| 1. |
- Yates, James A. Fellows, et al.
(författare)
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The evolution and changing ecology of the African hominid oral microbiome
- 2021
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences (PNAS). - 0027-8424 .- 1091-6490. ; 118:20
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Tidskriftsartikel (refereegranskat)abstract
- The oral microbiome plays key roles in human biology, health, and disease, but little is known about the global diversity, variation, or evolution of this microbial community. To better understand the evolution and changing ecology of the human oral microbiome, we analyzed 124 dental biofilm metagenomes from humans, including Neanderthals and Late Pleistocene to present-day modern humans, chimpanzees, and gorillas, as well as New World howler monkeys for comparison. We find that a core microbiome of primarily biofilm structural taxa has been maintained throughout African hominid evolution, and these microbial groups are also shared with howler monkeys, suggesting that they have been important oral members since before the catarrhine-platyrrhine split ca. 40 Mya. However, community structure and individual microbial phylogenies do not closely reflect host relationships, and the dental biofilms of Homo and chimpanzees are distinguished by major taxonomic and functional differences. Reconstructing oral metagenomes from up to 100 thousand years ago, we show that the microbial profiles of both Neanderthals and modern humans are highly similar, sharing functional adaptations in nutrient metabolism. These include an apparent Homo-specific acquisition of salivary amylase-binding capability by oral streptococci, suggesting microbial coadaptation with host diet. We additionally find evidence of shared genetic diversity in the oral bacteria of Neanderthal and Upper Paleolithic modern humans that is not observed in later modern human populations. Differences in the oral microbiomes of African hominids provide insights into human evolution, the ancestral state of the human microbiome, and a temporal framework for understanding microbial health and disease.
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| 2. |
- Arandjelovic, M., et al.
(författare)
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Two-step multiplex polymerase chain reaction improves the speed and accuracy of genotyping using DNA from noninvasive and museum samples
- 2009
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Ingår i: Molecular Ecology Resources. - : Wiley. - 1755-098X .- 1755-0998. ; 9:1, s. 28-36
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Tidskriftsartikel (refereegranskat)abstract
- Many studies in molecular ecology rely upon the genotyping of large numbers of low‐quantity DNA extracts derived from noninvasive or museum specimens. To overcome low amplification success rates and avoid genotyping errors such as allelic dropout and false alleles, multiple polymerase chain reaction (PCR) replicates for each sample are typically used. Recently, two‐step multiplex procedures have been introduced which drastically increase the success rate and efficiency of genotyping. However, controversy still exists concerning the amount of replication needed for suitable control of error. Here we describe the use of a two‐step multiplex PCR procedure that allows rapid genotyping using at least 19 different microsatellite loci. We applied this approach to quantified amounts of noninvasive DNAs from western chimpanzee, western gorilla, mountain gorilla and black and white colobus faecal samples, as well as to DNA from ~100‐year‐old gorilla teeth from museums. Analysis of over 45 000 PCRs revealed average success rates of > 90% using faecal DNAs and 74% using museum specimen DNAs. Average allelic dropout rates were substantially reduced compared to those obtained using conventional singleplex PCR protocols, and reliable genotyping using low (< 25 pg) amounts of template DNA was possible. However, four to five replicates of apparently homozygous results are needed to avoid allelic dropout when using the lowest concentration DNAs (< 50 pg/reaction), suggesting that use of protocols allowing routine acceptance of homozygous genotypes after as few as three replicates may lead to unanticipated errors when applied to low‐concentration DNAs.
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| 3. |
- Baas, Pauline, et al.
(författare)
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Population-level assessment of genetic diversity and habitat fragmentation in critically endangered Grauer's gorillas
- 2018
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Ingår i: American Journal of Physical Anthropology. - : Wiley. - 0002-9483 .- 1096-8644. ; 165:3, s. 565-575
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The critically endangered Grauer's gorilla (Gorilla beringei graueri) has experienced an estimated 77% population decline within a single generation. Although crucial for informed conservation decisions, there is no clear understanding about population structure and distribution of genetic diversity across the species' highly fragmented range. We fill this gap by studying several core and peripheral Grauer's gorilla populations throughout their distribution range.Materials and Methods: We generated genetic profiles for a sampling of an unstudied population of Grauer's gorillas from within the species' core range at 13 autosomal microsatellite loci and combined them with previously published and newly generated data from four other Grauer's gorilla populations, two mountain gorilla populations, and one western lowland gorilla population.Results: In agreement with previous studies, the genetic diversity of Grauer's gorillas is intermediate, falling between western lowland and mountain gorillas. Among Grauer's gorilla populations, we observe lower genetic diversity and high differentiation in peripheral compared with central populations, indicating a strong effect of genetic drift and limited gene flow among small, isolated forest fragments.Discussion: Although genetically less diverse, peripheral populations are frequently essential for the long-term persistence of a species and migration between peripheral and core populations may significantly enrich the overall species genetic diversity. Thus, in addition to central Grauer's gorilla populations from the core of the distribution range that clearly deserve conservation attention, we argue that conservation strategies aiming to ensure long-term species viability should include preserving peripheral populations and enhancing habitat connectivity.
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| 4. |
- Brealey, Jaelle C., et al.
(författare)
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Dental Calculus as a Tool to Study the Evolution of the Mammalian Oral Microbiome
- 2020
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Ingår i: Molecular biology and evolution. - : OXFORD UNIV PRESS. - 0737-4038 .- 1537-1719. ; 37:10, s. 3003-3022
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Tidskriftsartikel (refereegranskat)abstract
- Dental calculus, the calcified form of the mammalian oral microbial plaque biofilm, is a rich source of oral microbiome, host, and dietary biomolecules and is well preserved in museum and archaeological specimens. Despite its wide presence in mammals, to date, dental calculus has primarily been used to study primate microbiome evolution. We establish dental calculus as a valuable tool for the study of nonhuman host microbiome evolution, by using shotgun metagenomics to characterize the taxonomic and functional composition of the oral microbiome in species as diverse as gorillas, bears, and reindeer. We detect oral pathogens in individuals with evidence of oral disease, assemble near-complete bacterial genomes from historical specimens, characterize antibiotic resistance genes, reconstruct components of the host diet, and recover host genetic profiles. Our work demonstrates that metagenomic analyses of dental calculus can be performed on a diverse range of mammalian species, which will allow the study of oral microbiome and pathogen evolution from a comparative perspective. As dental calculus is readily preserved through time, it can also facilitate the quantification of the impact of anthropogenic changes on wildlife and the environment.
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| 5. |
- Brealey, Jaelle C., et al.
(författare)
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The oral microbiota of wild bears in Sweden reflects the history of antibiotic use by humans
- 2021
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Ingår i: Current Biology. - : Elsevier BV. - 0960-9822 .- 1879-0445. ; 31:20, s. 4650-4658.e6
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Tidskriftsartikel (refereegranskat)abstract
- Following the advent of industrial-scale antibiotic production in the 1940s,1 antimicrobial resistance (AMR) has been on the rise and now poses a major global health threat in terms of mortality, morbidity, and economic burden.2,3 Because AMR can be exchanged between humans, livestock, and wildlife, wild animals can be used as indicators of human-associated AMR contamination of the environment.4 However, AMR is a normal function of natural environments and is present in host-associated microbiomes, which makes it challenging to distinguish between anthropogenic and natural sources.4,5 One way to overcome this difficulty is to use historical samples that span the period from before the mass production of antibiotics to today. We used shotgun metagenomic sequencing of dental calculus, the calcified form of the oral microbial biofilm, to determine the abundance and repertoire of AMR genes in the oral microbiome of Swedish brown bears collected over the last 180 years. Our temporal metagenomics approach allowed us to establish a baseline of natural AMR in the pre-antibiotics era and to quantify a significant increase in total AMR load and diversity of AMR genes that is consistent with patterns of national human antibiotic use. We also demonstrated a significant decrease in total AMR load in bears in the last two decades, which coincides with Swedish strategies to mitigate AMR. Our study suggests that public health policies can be effective in limiting human-associated AMR contamination of the environment and wildlife.
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| 6. |
- Dehasque, Marianne, et al.
(författare)
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Inference of natural selection from ancient DNA
- 2020
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Ingår i: Evolution Letters. - : JOHN WILEY & SONS LTD. - 2056-3744. ; 4:2, s. 94-108
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Evolutionary processes, including selection, can be indirectly inferred based on patterns of genomic variation among contemporary populations or species. However, this often requires unrealistic assumptions of ancestral demography and selective regimes. Sequencing ancient DNA from temporally spaced samples can inform about past selection processes, as time series data allow direct quantification of population parameters collected before, during, and after genetic changes driven by selection. In this Comment and Opinion, we advocate for the inclusion of temporal sampling and the generation of paleogenomic datasets in evolutionary biology, and highlight some of the recent advances that have yet to be broadly applied by evolutionary biologists. In doing so, we consider the expected signatures of balancing, purifying, and positive selection in time series data, and detail how this can advance our understanding of the chronology and tempo of genomic change driven by selection. However, we also recognize the limitations of such data, which can suffer from postmortem damage, fragmentation, low coverage, and typically low sample size. We therefore highlight the many assumptions and considerations associated with analyzing paleogenomic data and the assumptions associated with analytical methods.
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| 7. |
- Dussex, Nicolas, et al.
(författare)
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Population genomics of the critically endangered kākāpō
- 2021
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Ingår i: Cell Genomics. - : Elsevier BV. - 2666-979X. ; 1:1
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Tidskriftsartikel (refereegranskat)abstract
- Summary The kākāpō is a flightless parrot endemic to New Zealand. Once common in the archipelago, only 201 individuals remain today, most of them descending from an isolated island population. We report the first genome-wide analyses of the species, including a high-quality genome assembly for kākāpō, one of the first chromosome-level reference genomes sequenced by the Vertebrate Genomes Project (VGP). We also sequenced and analyzed 35 modern genomes from the sole surviving island population and 14 genomes from the extinct mainland population. While theory suggests that such a small population is likely to have accumulated deleterious mutations through genetic drift, our analyses on the impact of the long-term small population size in kākāpō indicate that present-day island kākāpō have a reduced number of harmful mutations compared to mainland individuals. We hypothesize that this reduced mutational load is due to the island population having been subjected to a combination of genetic drift and purging of deleterious mutations, through increased inbreeding and purifying selection, since its isolation from the mainland ∼10,000 years ago. Our results provide evidence that small populations can survive even when isolated for hundreds of generations. This work provides key insights into kākāpō breeding and recovery and more generally into the application of genetic tools in conservation efforts for endangered species.
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| 8. |
- Gao, Hong, et al.
(författare)
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The landscape of tolerated genetic variation in humans and primates
- 2023
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 380:6648
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Tidskriftsartikel (refereegranskat)abstract
- Personalized genome sequencing has revealed millions of genetic differences between individuals, but our understanding of their clinical relevance remains largely incomplete. To systematically decipher the effects of human genetic variants, we obtained whole-genome sequencing data for 809 individuals from 233 primate species and identified 4.3 million common protein-altering variants with orthologs in humans. We show that these variants can be inferred to have nondeleterious effects in humans based on their presence at high allele frequencies in other primate populations. We use this resource to classify 6% of all possible human protein-altering variants as likely benign and impute the pathogenicity of the remaining 94% of variants with deep learning, achieving state-of-the-art accuracy for diagnosing pathogenic variants in patients with genetic diseases.
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| 9. |
- Guschanski, Katerina, Dr. 1978-, et al.
(författare)
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Counting elusive animals : Comparing field and genetic census of the entire mountain gorilla population of Bwindi Impenetrable National Park, Uganda
- 2009
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Ingår i: Biological Conservation. - : Elsevier BV. - 0006-3207 .- 1873-2917. ; 142:2, s. 290-300
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Tidskriftsartikel (refereegranskat)abstract
- Accurate population size estimates are an essential part of every effective management plan for conserving endangered species. However, censusing rare and elusive wild animals is challenging and often relies on counting indirect signs, such as nests or feces. Despite widespread use, the accuracy of such estimates has rarely been evaluated. Here we compare an estimate of population size derived solely from field data with that obtained from a combination of field and genetic data for the critically endangered population of mountain gorillas (Gorilla beringei beringei) in Bwindi Impenetrable National Park, Uganda. After genotyping DNA from 384 fecal samples at 16 microsatellite loci, the population size estimate was reduced by 10.1% to 302 individuals, compared with 336 gorillas estimated using the traditional nest-count based method alone. We found that both groups and lone silverbacks were double-counted in the field and that individuals constructed multiple nests with an overall rate of 7.8%, resulting in the overestimation of the population size in the absence of genetic data. Since the error associated with the traditional field method exceeded the estimated population growth of 5% in the last 4 years, future genetic censusing will be needed to determine how the population size is changing. This study illustrates that newly improved molecular methods allow fast, efficient and relatively affordable genotyping of several hundred samples, suggesting that genetic censusing can be widely applied to provide accurate and reliable population size estimates for a wide variety of species. (C) 2008 Elsevier Ltd. All rights reserved.
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| 10. |
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| 11. |
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| 12. |
- Guschanski, Katerina, Dr. 1978-, et al.
(författare)
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Next-Generation Museomics Disentangles One of the Largest Primate Radiations
- 2013
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Ingår i: Systematic Biology. - : Oxford University Press (OUP). - 1063-5157 .- 1076-836X. ; 62:4, s. 539-554
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Tidskriftsartikel (refereegranskat)abstract
- Guenons (tribe Cercopithecini) are one of the most diverse groups of primates. They occupy all of sub-Saharan Africa and show great variation in ecology, behavior, and morphology. This variation led to the description of over 60 species and subspecies. Here, using next-generation DNA sequencing (NGS) in combination with targeted DNA capture, we sequenced 92 mitochondrial genomes from museum-preserved specimens as old as 117 years. We infer evolutionary relationships and estimate divergence times of almost all guenon taxa based on mitochondrial genome sequences. Using this phylogenetic framework, we infer divergence dates and reconstruct ancestral geographic ranges. We conclude that the extraordinary radiation of guenons has been a complex process driven by, among other factors, localized fluctuations of African forest cover. We find incongruences between phylogenetic trees reconstructed from mitochondrial and nuclear DNA sequences, which can be explained by either incomplete lineage sorting or hybridization. Furthermore, having produced the largest mitochondrial DNA data set from museum specimens, we document how NGS technologies can “unlock” museum collections, thereby helping to unravel the tree-of-life. [Museum collection; next-generation DNA sequencing; primate radiation; speciation; target capture.]
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| 13. |
- Guschanski, Katerina, Dr. 1978-
(författare)
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Recent Loss of Genetic Diversity in Eastern Gorillas
- 2020
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Ingår i: eLS. - : Wiley-Blackwell. - 9780470015902
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Many primate populations are declining as a result of human activities. Eastern gorillas are the most affected of all great apes. Understanding the genomic consequences of rapid declines is important for assessing conservation needs. Genomic analyses of museum specimens that predate the most recent changes allow for quantification of the genomic effects of population declines and extinctions. Grauer's gorillas, one of the two Eastern gorilla subspecies, have declined by almost 80% in the last two decades. Comparisons of genomic changes over the last 100 years revealed severe reduction in genetic diversity and increase in inbreeding and frequency of deleterious mutations. The other subspecies, the Mountain gorilla, has experienced little genomic change, possibly as a result of both long‐term evolutionary history and recent conservation efforts over the last 60 years. There is thus hope for the critically endangered species if appropriate conservation actions are taken.
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| 14. |
- Hold, Katharina, et al.
(författare)
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Ancient reindeer mitogenomes reveal island-hopping colonisation of the Arctic archipelagos
- 2024
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Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Climate warming at the end of the last glacial period had profound effects on the distribution of cold-adapted species. As their range shifted towards northern latitudes, they were able to colonise previously glaciated areas, including remote Arctic islands. However, there is still uncertainty about the routes and timing of colonisation. At the end of the last ice age, reindeer/caribou (Rangifer tarandus) expanded to the Holarctic region and colonised the archipelagos of Svalbard and Franz Josef Land. Earlier studies have proposed two possible colonisation routes, either from the Eurasian mainland or from Canada via Greenland. Here, we used 174 ancient, historical and modern mitogenomes to reconstruct the phylogeny of reindeer across its whole range and to infer the colonisation route of the Arctic islands. Our data shows a close affinity among Svalbard, Franz Josef Land and Novaya Zemlya reindeer. We also found tentative evidence for positive selection in the mitochondrial gene ND4, which is possibly associated with increased heat production. Our results thus support a colonisation of the Eurasian Arctic archipelagos from the Eurasian mainland and provide some insights into the evolutionary history and adaptation of the species to its High Arctic habitat.
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| 15. |
- Hooper, Rebecca, et al.
(författare)
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Host-derived population genomics data provides insights into bacterial and diatom composition of the killer whale skin
- 2019
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Ingår i: Molecular Ecology. - : John Wiley & Sons. - 0962-1083 .- 1365-294X. ; 28:2, s. 484-502
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Tidskriftsartikel (refereegranskat)abstract
- Recent exploration into the interactions and relationship between hosts and their microbiota has revealed a connection between many aspects of the host's biology, health and associated micro-organisms. Whereas amplicon sequencing has traditionally been used to characterize the microbiome, the increasing number of published population genomics data sets offers an underexploited opportunity to study microbial profiles from the host shotgun sequencing data. Here, we use sequence data originally generated from killer whale Orcinus orca skin biopsies for population genomics, to characterize the skin microbiome and investigate how host social and geographical factors influence the microbial community composition. Having identified 845 microbial taxa from 2.4 million reads that did not map to the killer whale reference genome, we found that both ecotypic and geographical factors influence community composition of killer whale skin microbiomes. Furthermore, we uncovered key taxa that drive the microbiome community composition and showed that they are embedded in unique networks, one of which is tentatively linked to diatom presence and poor skin condition. Community composition differed between Antarctic killer whales with and without diatom coverage, suggesting that the previously reported episodic migrations of Antarctic killer whales to warmer waters associated with skin turnover may control the effects of potentially pathogenic bacteria such as Tenacibaculum dicentrarchi. Our work demonstrates the feasibility of microbiome studies from host shotgun sequencing data and highlights the importance of metagenomics in understanding the relationship between host and microbial ecology.
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| 16. |
- Jensen, Axel, et al.
(författare)
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Complex Evolutionary History With Extensive Ancestral Gene Flow in an African Primate Radiation
- 2023
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Ingår i: Molecular biology and evolution. - : Oxford University Press. - 0737-4038 .- 1537-1719. ; 40:12
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the drivers of speciation is fundamental in evolutionary biology, and recent studies highlight hybridization as an important evolutionary force. Using whole-genome sequencing data from 22 species of guenons (tribe Cercopithecini), one of the world's largest primate radiations, we show that rampant gene flow characterizes their evolutionary history and identify ancient hybridization across deeply divergent lineages that differ in ecology, morphology, and karyotypes. Some hybridization events resulted in mitochondrial introgression between distant lineages, likely facilitated by cointrogression of coadapted nuclear variants. Although the genomic landscapes of introgression were largely lineage specific, we found that genes with immune functions were overrepresented in introgressing regions, in line with adaptive introgression, whereas genes involved in pigmentation and morphology may contribute to reproductive isolation. In line with reports from other systems that hybridization might facilitate diversification, we find that some of the most species-rich guenon clades are of admixed origin. This study provides important insights into the prevalence, role, and outcomes of ancestral hybridization in a large mammalian radiation.
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| 17. |
- Kuderna, Lukas F. K., et al.
(författare)
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A global catalog of whole-genome diversity from 233 primate species
- 2023
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 380:6648, s. 906-913
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Tidskriftsartikel (refereegranskat)abstract
- The rich diversity of morphology and behavior displayed across primate species provides an informative context in which to study the impact of genomic diversity on fundamental biological processes. Analysis of that diversity provides insight into long-standing questions in evolutionary and conservation biology and is urgent given severe threats these species are facing. Here, we present high-coverage wholegenome data from 233 primate species representing 86% of genera and all 16 families. This dataset was used, together with fossil calibration, to create a nuclear DNA phylogeny and to reassess evolutionary divergence times among primate clades. We found within-species genetic diversity across families and geographic regions to be associated with climate and sociality, but not with extinction risk. Furthermore, mutation rates differ across species, potentially influenced by effective population sizes. Lastly, we identified extensive recurrence of missense mutations previously thought to be human specific. This study will open a wide range of research avenues for future primate genomic research.
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| 18. |
- Kuderna, Lukas F. K., et al.
(författare)
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Identification of constrained sequence elements across 239 primate genomes
- 2024
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Ingår i: Nature. - : Springer Nature. - 0028-0836 .- 1476-4687. ; 625:7996, s. 735-742
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Tidskriftsartikel (refereegranskat)abstract
- Noncoding DNA is central to our understanding of human gene regulation and complex diseases1,2, and measuring the evolutionary sequence constraint can establish the functional relevance of putative regulatory elements in the human genome3,4,5,6,7,8,9. Identifying the genomic elements that have become constrained specifically in primates has been hampered by the faster evolution of noncoding DNA compared to protein-coding DNA10, the relatively short timescales separating primate species11, and the previously limited availability of whole-genome sequences12. Here we construct a whole-genome alignment of 239 species, representing nearly half of all extant species in the primate order. Using this resource, we identified human regulatory elements that are under selective constraint across primates and other mammals at a 5% false discovery rate. We detected 111,318 DNase I hypersensitivity sites and 267,410 transcription factor binding sites that are constrained specifically in primates but not across other placental mammals and validate their cis-regulatory effects on gene expression. These regulatory elements are enriched for human genetic variants that affect gene expression and complex traits and diseases. Our results highlight the important role of recent evolution in regulatory sequence elements differentiating primates, including humans, from other placental mammals.
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| 19. |
- Malukiewicz, Joanna, et al.
(författare)
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Application of PE-RADSeq to the study of genomic diversity and divergence of two Brazilian marmoset species (Callithrix jacchus and C-penicillata)
- 2017
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Ingår i: American Journal of Primatology. - : WILEY. - 0275-2565 .- 1098-2345. ; 79:2
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Tidskriftsartikel (refereegranskat)abstract
- Callithrix jacchus and C. penicillata are among the smallest anthropoid primates, are highly specialized tree gougers, and largely occupy Brazil's most extreme, semi-arid biomes. However, the underlying genomic factors that underpin the evolution of these species and their unique traits are under-investigated. Additionally, exotic populations of these two species are widely established throughout Brazil and hybridize with threatened native congers. Thus, both genomic and conservation factors call for a better understanding of C. jacchus and C. penicillata evolution. Here, we applied PE-RADseq to characterize genomic variation in these two species, using six C. jacchus and seven C. penicillata individuals. We identified an average of 7,463 and 5,180 SNPs/individual in C. penicillata and C. jacchus, respectively, and also found 1,395 variable sites that were represented in both species. C. penicillata showed overall higher levels of genetic diversity than C. jacchus at the variable sites present in both species. Additionally, among these variable sites, 106 showed relative interspecific divergence levels that were significantly higher than the genome-wide average. We further compared relative and absolute divergence for C. penicillata and C. jacchus between RAD loci associated with the 106 significantly diverged variable sites and all other RAD loci present in both species. The former RAD loci set showed significantly elevated relative and absolute divergence measures in comparison to the latter set. This convergence suggests that C. jacchus and C. penicillata may have diverged under a scenario of gene flow under secondary contact. Here, we demonstrate that RADseq is an efficient method to simultaneously discover and genotype a large number of markers and validate the utility of RADseq for examining Callithrix evolution.
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| 20. |
- Malukiewicz, Joanna, et al.
(författare)
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Phylogeny of the jacchus group of Callithrix marmosets based on complete mitochondrial genomes
- 2017
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Ingår i: American Journal of Physical Anthropology. - : WILEY-BLACKWELL. - 0002-9483 .- 1096-8644. ; 162:1, s. 157-169
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Tidskriftsartikel (refereegranskat)abstract
- ObjectivesTwo subgroups make up the marmoset genus Callithrix. The "aurita" group is composed of two species, whereas evolutionary relationships among the four species of the "jacchus" group remain unclear. To uncover these relationships, we first sequenced mitochondrial genomes for C. kuhlii and C. penicillata to complement data available for congeners. We then constructed a phylogenetic tree based on mtDNA heavy chain protein coding genes from several primates to untangle species relationships and estimate divergence times of the jacchus group. Materials and MethodsMtDNA genomes of C. kuhlii and C. penicillata were Sanger sequenced. These Callithrix mitogenomes were combined with other publically available primate mtDNA genomes. Phylogenies were produced using maximum likelihood and Bayesian inference. Finally, divergence times within the jacchus group of marmosets were estimated with Bayesian inference. ResultsIn our phylogenetic tree, C. geoffroyi was the sister to all other jacchus group species, followed by C. kuhlii, while C. jacchus and C. penicillata diverged most recently. Bayesian inference showed that C. jacchus and C. penicillata diverged approximately 0.70 MYA and that the jacchus group radiated approximately 1.30 MYA. DiscussionCallithrix nuclear and mtDNA phylogenies frequently result in polytomies and paraphyly. Here, we present a well-supported phylogenetic tree based on mitochondrial genome sequences, which facilitates the understanding of the divergence of the jacchus marmosets. Our results demonstrate how mitochondrial genomes can enrich Callithrix phylogenetic studies by alleviating some of the difficulties faced by previous mtDNA studies and allow formulation of hypotheses to test further under larger genomic-scale analyses.
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| 21. |
- Meunier, Julien, et al.
(författare)
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Birth and expression evolution of mammalian microRNA genes
- 2013
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Ingår i: Genome Research. - : Cold Spring Harbor Laboratory. - 1088-9051 .- 1549-5469. ; 23:1, s. 34-45
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Tidskriftsartikel (refereegranskat)abstract
- MicroRNAs (miRNAs) are major post-transcriptional regulators of gene expression, yet their origins and functional evolution in mammals remain little understood due to the lack of appropriate comparative data. Using RNA sequencing, we have generated extensive and comparable miRNA data for five organs in six species that represent all main mammalian lineages and birds (the evolutionary outgroup) with the aim to unravel the evolution of mammalian miRNAs. Our analyses reveal an overall expansion of miRNA repertoires in mammals, with threefold accelerated birth rates of miRNA families in placentals and marsupials, facilitated by the de novo emergence of miRNAs in host gene introns. Generally, our analyses suggest a high rate of miRNA family turnover in mammals with many newly emerged miRNA families being lost soon after their formation. Selectively preserved mammalian miRNA families gradually evolved higher expression levels, as well as altered mature sequences and target gene repertoires, and were apparently mainly recruited to exert regulatory functions in nervous tissues. However, miRNAs that originated on the X chromosome evolved high expression levels and potentially diverse functions during spermatogenesis, including meiosis, through selectively driven duplication-divergence processes. Overall, our study thus provides detailed insights into the birth and evolution of mammalian miRNA genes and the associated selective forces.
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| 22. |
- Michel, Alice, et al.
(författare)
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Isolated Grauer's gorilla populations differ in diet and gut microbiome
- 2023
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Ingår i: Molecular Ecology. - : John Wiley & Sons. - 0962-1083 .- 1365-294X. ; 32:23, s. 6523-6542
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Tidskriftsartikel (refereegranskat)abstract
- The animal gut microbiome has been implicated in a number of key biological processes, ranging from digestion to behaviour, and has also been suggested to facilitate local adaptation. Yet studies in wild animals rarely compare multiple populations that differ ecologically, which is the level at which local adaptation may occur. Further, few studies simultaneously characterize diet and gut microbiome from the same sample, despite their probable interdependence. Here, we investigate the interplay between diet and gut microbiome in three geographically isolated populations of the critically endangered Grauer's gorilla (Gorilla beringei graueri), which we show to be genetically differentiated. We find population- and social group-specific dietary and gut microbial profiles and covariation between diet and gut microbiome, despite the presence of core microbial taxa. There was no detectable effect of age, and only marginal effects of sex and genetic relatedness on the microbiome. Diet differed considerably across populations, with the high-altitude population consuming a lower diversity of plants compared to low-altitude populations, consistent with plant availability constraining dietary choices. The observed pattern of covariation between diet and gut microbiome is probably a result of long-term social and environmental factors. Our study suggests that the gut microbiome is sufficiently plastic to support flexible food selection and hence contribute to local adaptation.
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| 23. |
- Moraitou, Markella, et al.
(författare)
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Ecology, Not Host Phylogeny, Shapes the Oral Microbiome in Closely Related Species
- 2022
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Ingår i: Molecular biology and evolution. - : Oxford University Press. - 0737-4038 .- 1537-1719. ; 39:12
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Tidskriftsartikel (refereegranskat)abstract
- Host-associated microbiomes are essential for a multitude of biological processes. Placed at the contact zone between external and internal environments, the little-studied oral microbiome has important roles in host physiology and health. Here, we investigate the roles of host evolutionary relationships and ecology in shaping the oral microbiome in three closely related gorilla subspecies (mountain, Grauer's, and western lowland gorillas) using shotgun metagenomics of 46 museum-preserved dental calculus samples. We find that the oral microbiomes of mountain gorillas are functionally and taxonomically distinct from the other two subspecies, despite close evolutionary relationships and geographic proximity with Grauer's gorillas. Grauer's gorillas show intermediate bacterial taxonomic and functional, and dietary profiles. Altitudinal differences in gorilla subspecies ranges appear to explain these patterns, suggesting a close connection between dental calculus microbiomes and the environment, likely mediated through diet. This is further supported by the presence of gorilla subspecies-specific phyllosphere/rhizosphere taxa in the oral microbiome. Mountain gorillas show a high abundance of nitrate-reducing oral taxa, which may promote adaptation to a high-altitude lifestyle by modulating blood pressure. Our results suggest that ecology, rather than evolutionary relationships and geographic distribution, shape the oral microbiome in these closely related species.
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| 24. |
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| 25. |
- Pawar, Harvinder, et al.
(författare)
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Ghost admixture in eastern gorillas
- 2023
-
Ingår i: Nature Ecology & Evolution. - : Springer Nature. - 2397-334X. ; 7:9, s. 1503-1514
-
Tidskriftsartikel (refereegranskat)abstract
- Archaic admixture has had a significant impact on human evolution with multiple events across different clades, including from extinct hominins such as Neanderthals and Denisovans into modern humans. Within the great apes archaic admixture has been identified in chimpanzees and bonobos, but the possibility of such events has not been explored in other species. Here, we address this question using high-coverage whole genome sequences from all four extant gorilla subspecies, including six newly sequenced eastern gorillas from previously unsampled geographic regions. Using Approximate Bayesian Computation (ABC) with neural networks to model the demographic history of gorillas, we find a signature of admixture from an archaic 'ghost' lineage into the common ancestor of eastern gorillas, but not western gorillas. We infer that up to 3% of the genome of these individuals is introgressed from an archaic lineage that diverged more than 3 million years ago from the common ancestor of all extant gorillas. This introgression event took place before the split of mountain and eastern lowland gorillas, likely more than 40 thousand years ago, and may have influenced perception of bitter taste in eastern gorillas. When comparing the introgression landscapes of gorillas, humans and bonobos, we find a consistent depletion of introgressed fragments on the X chromosome across these species. However, depletion in protein-coding content is not detectable in eastern gorillas, possibly as a consequence of stronger genetic drift in this species.
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| 26. |
- Porter, Amy, et al.
(författare)
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Behavioral responses around conspecific corpses in adult eastern gorillas (Gorilla beringei spp.)
- 2019
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Ingår i: PeerJ. - : PEERJ INC. - 2167-8359. ; 7
-
Tidskriftsartikel (refereegranskat)abstract
- Humans were once considered unique in having a concept of death but a growing number of observations of animal responses to dying and dead conspecifics suggests otherwise. Complex arrays of behaviors have been described ranging from corpse removal and burial among social insects to quiet attendance and caregiving among elephants and primates. Less frequently described, however, are behavioral responses of individuals from different age/sex classes or social position toward the death of conspecifics. We describe behavioral responses of mountain gorillas (Gorilla beringei beringei) to the deaths of a dominant silverback and a dominant adult female from the same social group in Volcanoes National Park in Rwanda and the responses of Grauer's gorillas (Gorilla b. graueri) to the corpse of an extra-group silverback in Kahuzi-Biega National Park, Democratic Republic of Congo. In gorillas, interactions between groups or with a lone silverback often result in avoidance or aggression. We predicted that: (i) more individuals should interact with the corpses of same-group members than with the corpse of the extra-group silverback; (ii) adult females with infants should avoid the corpse of the extra-group silverback; and (iii) in the mountain gorilla cases, individuals that shared close social relationships with the dead individual should spend more time with the corpse than other individuals in the group. We used a combination of detailed qualitative reports, photos, and videos to describe all occurrences of affiliative/investigative and agonistic behaviors observed at the corpses. We observed similar responses toward the corpses of group and extra-group individuals. Animals in all three cases showed a variety of affiliative/investigative and agonistic behaviors directed to the corpses. Animals of all age/sex classes interacted with the corpses in affiliative/investigative ways but there was a notable absence of all adult females at the corpse of the extra-group silverback. In all three cases, we observed only silverbacks and blackbacks being agonistic around and/or toward the corpses. In the mountain gorilla cases, the individuals who spent the most time with the corpses were animals who shared close social relationships with the deceased. We emphasize the similarity in the behavioral responses around the corpses of group and extra-group individuals, and suggest that the behavioral responses were influenced in part by close social relationships between the deceased and certain group members and by a general curiosity about death. We further discuss the implications close interactions with corpses have for disease transmission within and between gorilla social groups.
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| 27. |
- Prost, Stefan, et al.
(författare)
-
Genomic analyses show extremely perilous conservation status of African and Asiatic cheetahs (Acinonyx jubatus)
- 2022
-
Ingår i: Molecular Ecology. - : John Wiley & Sons. - 0962-1083 .- 1365-294X. ; 31:16, s. 4208-4223
-
Tidskriftsartikel (refereegranskat)abstract
- We live in a world characterized by biodiversity loss and global environmental change. The extinction of large carnivores can have ramifying effects on ecosystems like an uncontrolled increase in wild herbivores, which in turn can have knock-on impacts on vegetation regeneration and communities. Cheetahs (Acinonyx jubatus) serve important ecosystem functions as apex predators; yet, they are quickly heading towards an uncertain future. Threatened by habitat loss, human-wildlife conflict and illegal trafficking, there are only approximately 7100 individuals remaining in nature. We present the most comprehensive genome-wide analysis of cheetah phylogeography and conservation genomics to date, assembling samples from nearly the entire current and past species' range. We show that their phylogeography is more complex than previously thought, and that East African cheetahs (A. j. raineyi) are genetically distinct from Southern African individuals (A. j. jubatus), warranting their recognition as a distinct subspecies. We found strong genetic differentiation between all classically recognized subspecies, thus refuting earlier findings that cheetahs show only little differentiation. The strongest differentiation was observed between the Asiatic and all the African subspecies. We detected high inbreeding in the Critically Endangered Iranian (A. j. venaticus) and North-western (A. j. hecki) subspecies, and show that overall cheetahs, along with snow leopards, have the lowest genome-wide heterozygosity of all the big cats. This further emphasizes the cheetah's perilous conservation status. Our results provide novel and important information on cheetah phylogeography that can support evidence-based conservation policy decisions to help protect this species. This is especially relevant in light of ongoing and proposed translocations across subspecies boundaries, and the increasing threats of illegal trafficking.
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| 28. |
- Robbins, Martha M., et al.
(författare)
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Dispersal and reproductive careers of male mountain gorillas in Bwindi Impenetrable National Park, Uganda
- 2019
-
Ingår i: Primates. - : Springer Science and Business Media LLC. - 0032-8332 .- 1610-7365. ; 60:2, s. 133-142
-
Tidskriftsartikel (refereegranskat)abstract
- Dispersal is a key event in the life of an animal and it influences individual reproductive success. Male mountain gorillas exhibit both philopatry and dispersal, resulting in a mixed one-male and multimale social organization. However, little is known about the relationship between male dispersal or philopatry and reproductive careers in Bwindi mountain gorillas. Here we analyze data spanning from 1993 to 2017 on social groups in Bwindi Impenetrable National Park, Uganda to examine the proportion of males that disperse, age of dispersal, pathways to attaining alpha status, fate of dispersing males and philopatric males, and male tenure length as well as make comparisons of these variables to the Virunga mountain gorilla population. We report previously undocumented cases of dispersal by immature males and old males and we also observed the only known case of a fully mature male immigrating into a breeding group. We used genetic tracking of known individuals to estimate that a minimum of 25% of males that disperse to become solitary males eventually form new groups. No differences were found between the Bwindi and Virunga population in the age of male dispersal, the proportion of males that disperse, the age of alpha male acquisition, and dominance tenure length. The lack of differences may be due to small sample sizes or because the observed ecological variability does not lead to life history differences between the populations. Males in both populations follow variable strategies to attain alpha status leading to the variable one-male and multimale social organization, including dispersal to become solitary and eventually form a group, via group fissioning, usurping another alpha male, or inheriting the alpha position when a previous group leader dies.
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| 29. |
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| 30. |
- Roy, Justin, et al.
(författare)
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Recent divergences and size decreases of eastern gorilla populations
- 2014
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Ingår i: Biology Letters. - : The Royal Society. - 1744-9561 .- 1744-957X. ; 10:11
-
Tidskriftsartikel (refereegranskat)abstract
- Compared with other African apes, eastern gorillas (Gorilla beringei) have been little studied genetically. We used analysis of autosomal DNA genotypes obtained from non-invasively collected faecal samples to estimate the evolutionary histories of the two extant mountain gorilla populations and the closely related eastern lowland gorillas. Our results suggest that eastern lowland gorillas and mountain gorillas split beginning some 10 000 years ago, followed 5000 years ago by the split of the two mountain gorilla populations of Bwindi Impenetrable National Park and the Virungas Massif. All three populations have decreased in effective population size, with particularly substantial 10- fold decreases for the mountain gorillas. These dynamics probably reflect responses to habitat changes resulting from climate fluctuations over the past 20 000 years as well as increasing human influence in this densely populated region in the last several thousand years.
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| 31. |
- Sawyer, Susanna, et al.
(författare)
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Temporal Patterns of Nucleotide Misincorporations and DNA Fragmentation in Ancient DNA
- 2012
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:3
-
Tidskriftsartikel (refereegranskat)abstract
- DNA that survives in museum specimens, bones and other tissues recovered by archaeologists is invariably fragmented and chemically modified. The extent to which such modifications accumulate over time is largely unknown but could potentially be used to differentiate between endogenous old DNA and present-day DNA contaminating specimens and experiments. Here we examine mitochondrial DNA sequences from tissue remains that vary in age between 18 and 60,000 years with respect to three molecular features: fragment length, base composition at strand breaks, and apparent C to T substitutions. We find that fragment length does not decrease consistently over time and that strand breaks occur preferentially before purine residues by what may be at least two different molecular mechanisms that are not yet understood. In contrast, the frequency of apparent C to T substitutions towards the 5'-ends of molecules tends to increase over time. These nucleotide misincorporations are thus a useful tool to distinguish recent from ancient DNA sources in specimens that have not been subjected to unusual or harsh treatments.
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| 32. |
- Staedele, Veronika, et al.
(författare)
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The complex Y-chromosomal history of gorillas
- 2022
-
Ingår i: American Journal of Primatology. - : John Wiley & Sons. - 0275-2565 .- 1098-2345. ; 84:3
-
Tidskriftsartikel (refereegranskat)abstract
- Studies of the evolutionary relationships among gorilla populations using autosomal and mitochondrial sequences suggest that male-mediated gene flow may have been important in the past, but data on the Y-chromosomal relationships among the gorilla subspecies are limited. Here, we genotyped blood and noninvasively collected fecal samples from 12 captives and 257 wild male gorillas of known origin representing all four subspecies (Gorilla gorilla gorilla, G. g. diehli, G. beringei beringei, and G. b. graueri) at 10 Y-linked microsatellite loci resulting in 102 unique Y-haplotypes for 224 individuals. We found that western lowland gorilla (G. g. gorilla) haplotypes were consistently more diverse than any other subspecies for all measures of diversity and comprised several genetically distinct groups. However, these did not correspond to geographical proximity and some closely related haplotypes were found several hundred kilometers apart. Similarly, our broad sampling of eastern gorillas revealed that mountain (G. b. beringei) and Grauer's (G. b. graueri) gorilla Y-chromosomal haplotypes did not form distinct clusters. These observations suggest structure in the ancestral population with subsequent mixing of differentiated haplotypes by male dispersal for western lowland gorillas, and postisolation migration or incomplete lineage sorting due to short divergence times for eastern gorillas.
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| 33. |
- Thalmann, Olaf, et al.
(författare)
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Historical sampling reveals dramatic demographic changes in western gorilla populations
- 2011
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Ingår i: BMC Evolutionary Biology. - : Springer Science and Business Media LLC. - 1471-2148. ; 11
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Today many large mammals live in small, fragmented populations, but it is often unclear whether this subdivision is the result of long-term or recent events. Demographic modeling using genetic data can estimate changes in long-term population sizes while temporal sampling provides a way to compare genetic variation present today with that sampled in the past. In order to better understand the dynamics associated with the divergences of great ape populations, these analytical approaches were applied to western gorillas (Gorilla gorilla) and in particular to the isolated and Critically Endangered Cross River gorilla subspecies (G. g. diehli). Results: We used microsatellite genotypes from museum specimens and contemporary samples of Cross River gorillas to infer both the long-term and recent population history. We find that Cross River gorillas diverged from the ancestral western gorilla population similar to 17,800 years ago (95% HDI: 760, 63,245 years). However, gene flow ceased only similar to 420 years ago (95% HDI: 200, 16,256 years), followed by a bottleneck beginning similar to 320 years ago (95% HDI: 200, 2,825 years) that caused a 60 fold decrease in the effective population size of Cross River gorillas. Direct comparison of heterozygosity estimates from museum and contemporary samples suggests a loss of genetic variation over the last 100 years. Conclusions: The composite history of western gorillas could plausibly be explained by climatic oscillations inducing environmental changes in western equatorial Africa that would have allowed gorilla populations to expand over time but ultimately isolate the Cross River gorillas, which thereafter exhibited a dramatic population size reduction. The recent decrease in the Cross River population is accordingly most likely attributable to increasing anthropogenic pressure over the last several hundred years. Isolation of diverging populations with prolonged concomitant gene flow, but not secondary admixture, appears to be a typical characteristic of the population histories of African great apes, including gorillas, chimpanzees and bonobos.
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| 34. |
- Theissinger, Kathrin, et al.
(författare)
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How genomics can help biodiversity conservation
- 2023
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Ingår i: Trends in Genetics. - : Elsevier. - 0168-9525 .- 1362-4555. ; 39:7, s. 545-559
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Forskningsöversikt (refereegranskat)abstract
- The availability of public genomic resources can greatly assist biodiversity assessment, conservation, and restoration efforts by providing evidence for scientifically informed management decisions. Here we survey the main approaches and applications in biodiversity and conservation genomics, considering practical factors, such as cost, time, prerequisite skills, and current shortcomings of applications. Most approaches perform best in combination with reference genomes from the target species or closely related species. We review case studies to illustrate how reference genomes can facilitate biodiversity research and conservation across the tree of life. We conclude that the time is ripe to view reference genomes as fundamental resources and to integrate their use as a best practice in conservation genomics.
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| 35. |
- van der Valk, Tom, et al.
(författare)
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Comparative genomic analyses provide new insights into evolutionary history and conservation genomics of gorillas
- 2024
-
Ingår i: BMC Ecology and Evolution. - : BioMed Central (BMC). - 2730-7182. ; 24:1
-
Tidskriftsartikel (refereegranskat)abstract
- Genome sequencing is a powerful tool to understand species evolutionary history, uncover genes under selection, which could be informative of local adaptation, and infer measures of genetic diversity, inbreeding and mutational load that could be used to inform conservation efforts. Gorillas, critically endangered primates, have received considerable attention and with the recently sequenced Bwindi mountain gorilla population, genomic data is now available from all gorilla subspecies and both mountain gorilla populations. Here, we reanalysed this rich dataset with a focus on evolutionary history, local adaptation and genomic parameters relevant for conservation. We estimate a recent split between western and eastern gorillas of 150,000-180,000 years ago, with gene flow around 20,000 years ago, primarily between the Cross River and Grauer's gorilla subspecies. This gene flow event likely obscures evolutionary relationships within eastern gorillas: after excluding putatively introgressed genomic regions, we uncover a sister relationship between Virunga mountain gorillas and Grauer's gorillas to the exclusion of Bwindi mountain gorillas. This makes mountain gorillas paraphyletic. Eastern gorillas are less genetically diverse and more inbred than western gorillas, yet we detected lower genetic load in the eastern species. Analyses of indels fit remarkably well with differences in genetic diversity across gorilla taxa as recovered with nucleotide diversity measures. We also identified genes under selection and unique gene variants specific for each gorilla subspecies, encoding, among others, traits involved in immunity, diet, muscular development, hair morphology and behavior. The presence of this functional variation suggests that the subspecies may be locally adapted. In conclusion, using extensive genomic resources we provide a comprehensive overview of gorilla genomic diversity, including a so-far understudied Bwindi mountain gorilla population, identify putative genes involved in local adaptation, and detect population-specific gene flow across gorilla species.
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| 36. |
- van der Valk, Tom, et al.
(författare)
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Historical Genomes Reveal the Genomic Consequences of Recent Population Decline in Eastern Gorillas
- 2019
-
Ingår i: Current Biology. - : Elsevier BV. - 0960-9822 .- 1879-0445. ; 29:1, s. 165-170.e6
-
Tidskriftsartikel (refereegranskat)abstract
- Many endangered species have experienced severe population declines within the last centuries [1, 2]. However, despite concerns about negative fitness effects resulting from increased genetic drift and inbreeding, there is a lack of empirical data on genomic changes in conjunction with such declines [3-7]. Here, we use whole genomes recovered from century-old historical museum specimens to quantify the genomic consequences of small population size in the critically endangered Grauer's and endangered mountain gorillas. We find a reduction of genetic diversity and increase in inbreeding and genetic load in the Grauer's gorilla, which experienced severe population declines in recent decades. In contrast, the small but relatively stable mountain gorilla population has experienced little genomic change during the last century. These results suggest that species histories as well as the rate of demographic change may influence how population declines affect genome diversity.
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| 37. |
- van der Valk, Tom, et al.
(författare)
-
Index hopping on the Illumina HiseqX platform and its consequences for ancient DNA studies
- 2020
-
Ingår i: Molecular Ecology Resources. - : Wiley. - 1755-098X .- 1755-0998. ; 20:5, s. 1171-1181
-
Tidskriftsartikel (refereegranskat)abstract
- The high-throughput capacities of the Illumina sequencing platforms and the possibility to label samples individually have encouraged wide use of sample multiplexing. However, this practice results in read misassignment (usually <1%) across samples sequenced on the same lane. Alarmingly high rates of read misassignment of up to 10% were reported for lllumina sequencing machines with exclusion amplification chemistry. This may make use of these platforms prohibitive, particularly in studies that rely on low-quantity and low-quality samples, such as historical and archaeological specimens. Here, we use barcodes, short sequences that are ligated to both ends of the DNA insert, to directly quantify the rate of index hopping in 100-year old museum-preserved gorilla (Gorilla beringei) samples. Correcting for multiple sources of noise, we identify on average 0.470% of reads containing a hopped index. We show that sample-specific quantity of misassigned reads depends on the number of reads that any given sample contributes to the total sequencing pool, so that samples with few sequenced reads receive the greatest proportion of misassigned reads. This particularly affects ancient DNA samples, as these frequently differ in their DNA quantity and endogenous content. Through simulations we show that even low rates of index hopping, as reported here, can lead to biases in ancient DNA studies when multiplexing samples with vastly different quantities of endogenous material.
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| 38. |
- van der Valk, Tom, et al.
(författare)
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Significant loss of mitochondrial diversity within the last century due to extinction of peripheral populations in eastern gorillas
- 2018
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8
-
Tidskriftsartikel (refereegranskat)abstract
- Species and populations are disappearing at an alarming rate as a direct result of human activities. Loss of genetic diversity associated with population decline directly impacts species’ long-term survival. Therefore, preserving genetic diversity is of considerable conservation importance. However, to assist in conservation efforts, it is important to understand how genetic diversity is spatially distributed and how it changes due to anthropogenic pressures. In this study, we use historical museum and modern faecal samples of two critically endangered eastern gorilla taxa, Grauer’s (Gorilla beringei graueri) and mountain gorillas (Gorilla beringei beringei), to directly infer temporal changes in genetic diversity within the last century. Using over 100 complete mitochondrial genomes, we observe a significant decline in haplotype and nucleotide diversity in Grauer’s gorillas. By including historical samples from now extinct populations we show that this decline can be attributed to the loss of peripheral populations rather than a decrease in genetic diversity within the core range of the species. By directly quantifying genetic changes in the recent past, our study shows that human activities have severely impacted eastern gorilla genetic diversity within only four to five generations. This rapid loss calls for dedicated conservation actions, which should include preservation of the remaining peripheral populations.
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| 39. |
- van der Valk, Tom, et al.
(författare)
-
The genome of the endangered dryas monkey provides new insights into the evolutionary history of the vervets
- 2020
-
Ingår i: Molecular biology and evolution. - : Oxford University Press (OUP). - 0737-4038 .- 1537-1719. ; 37:1, s. 183-194
-
Tidskriftsartikel (refereegranskat)abstract
- Genomic data can be a powerful tool for inferring ecology, behaviour and conservation needs of highly elusive species, particularly when other sources of information are hard to come by. Here we focus on the dryas monkey, an endangered primate endemic to the Congo Basin with cryptic behaviour and possibly less than 250 remaining individuals. Using whole genome data we show that the dryas monkey represents a sister lineage to the vervet monkeys and has diverged from them at least 1 million years ago with additional bi-directional gene flow 590,000 – 360,000 years ago. After bonobo-chimpanzee admixture, this is the second reported case of gene flow that most likely involved crossing the Congo River, a strong dispersal barrier. As the demographic history of bonobos and dryas monkey shows similar patterns of population increase during this time period, we hypothesise that the fluvial topology of the Congo River might have been more dynamic than previously recognised. As a result of dryas monkey - vervet admixture, genes involved in resistance to the simian immunodeficiency virus (SIV) have been exchanged, possibly indicating adaptive introgression. Despite the presence of several homozygous loss-of-function mutations in genes associated with reduced sperm mobility and immunity, we find high genetic diversity and low levels of inbreeding and genetic load in the studied dryas monkey individual. This suggests that the current population carries sufficient genetic variability for the long-term survival of this species. We thus provide an example of how genomic data can directly improve our understanding of elusive species.
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| 40. |
- van der Valk, Tom, et al.
(författare)
-
Whole mitochondrial genome capture from faecal samples and museum-preserved specimens
- 2017
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Ingår i: Molecular Ecology Resources. - : Wiley. - 1755-098X .- 1755-0998. ; 17:6, s. e111-e121
-
Tidskriftsartikel (refereegranskat)abstract
- Population-scale molecular studies of endangered and cryptic species are often limited by access to high-quality samples. The use of noninvasively collected samples or museum-preserved specimens reduces the pressure on modern populations by removing the need to capture and handle live animals. However, endogenous DNA content in such samples is low, making shotgun sequencing a financially prohibitive approach. Here, we apply a target enrichment method to retrieve mitochondrial genomes from 65 museum specimens and 56 noninvasively collected faecal samples of two endangered great ape species, Grauer's gorilla and the eastern chimpanzee. We show that the applied method is suitable for a wide range of sample types that differ in endogenous DNA content, increasing the proportion of target reads to over 300-fold. By systematically evaluating biases introduced during target enrichment of pooled museum samples, we show that capture is less efficient for fragments shorter or longer than the baits, that the proportion of human contaminating reads increases postcapture although capture efficiency is lower for human compared to gorilla fragments with a gorilla-generated bait, and that the rate of jumping PCR is considerable, but can be controlled for with a double-barcoding approach. We succeed in capturing complete mitochondrial genomes from faecal samples, but observe reduced capture efficiency as sequence divergence increases between the bait and target species. As previously shown for museum specimens, we demonstrate here that mitochondrial genome capture from field-collected faecal samples is a robust and reliable approach for population-wide studies of nonmodel organisms.
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| 41. |
- Vigilant, Linda, et al.
(författare)
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Using genetics to understand the dynamics of wild primate populations
- 2009
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Ingår i: Primates. - : Springer Science and Business Media LLC. - 0032-8332 .- 1610-7365. ; 50:2, s. 105-120
-
Tidskriftsartikel (refereegranskat)abstract
- While much can be learned about primates by means of observation, the slow life history of many primates means that even decades of dedicated effort cannot illuminate long-term evolutionary processes. For example, while the size of a contemporary population can be estimated from field censuses, it is often desirable to know whether a population has been constant or changing in size over a time frame of hundreds or thousands of years. Even the nature of “a population” is open to question, and the extent to which individuals successfully disperse among defined populations is also difficult to estimate by using observational methods alone. Researchers have thus turned to genetic methods to examine the size, structure, and evolutionary histories of primate populations. Many results have been gained by study of sequence variation of maternally inherited mitochondrial DNA, but in recent years researchers have been increasingly focusing on analysis of short, highly variable microsatellite segments in the autosomal genome for a high-resolution view of evolutionary processes involving both sexes. In this review we describe some of the insights thus gained, and discuss the likely impact on this field of new technologies such as high-throughput DNA sequencing.
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| 42. |
- von Seth, J, et al.
(författare)
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Genomic insights into the conservation status of the world's last remaining Sumatran rhinoceros populations
- 2021
-
Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
-
Tidskriftsartikel (refereegranskat)abstract
- Small populations are often exposed to high inbreeding and mutational load that can increase the risk of extinction. The Sumatran rhinoceros was widespread in Southeast Asia, but is now restricted to small and isolated populations on Sumatra and Borneo, and most likely extinct on the Malay Peninsula. Here, we analyse 5 historical and 16 modern genomes from these populations to investigate the genomic consequences of the recent decline, such as increased inbreeding and mutational load. We find that the Malay Peninsula population experienced increased inbreeding shortly before extirpation, which possibly was accompanied by purging. The populations on Sumatra and Borneo instead show low inbreeding, but high mutational load. The currently small population sizes may thus in the near future lead to inbreeding depression. Moreover, we find little evidence for differences in local adaptation among populations, suggesting that future inbreeding depression could potentially be mitigated by assisted gene flow among populations.
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