1. |
- van der Meijden, Arie, et al.
(author)
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Target-Specificity in Scorpions : Comparing Lethality of Scorpion Venoms across Arthropods and Vertebrates
- 2017
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In: Toxins. - : MDPI. - 2072-6651. ; 9:10
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Journal article (peer-reviewed)abstract
- Scorpions use their venom in defensive situations as well as for subduing prey. Since some species of scorpion use their venom more in defensive situations than others, this may have led to selection for differences in effectiveness in defensive situations. Here, we compared the LD50 of the venom of 10 species of scorpions on five different species of target organisms; two insects and three vertebrates. We found little correlation between the target species in the efficacy of the different scorpion venoms. Only the two insects showed a positive correlation, indicating that they responded similarly to the panel of scorpion venoms. We discuss the lack of positive correlation between the vertebrate target species in the light of their evolution and development. When comparing the responses of the target systems to individual scorpion venoms pairwise, we found that closely related scorpion species tend to elicit a similar response pattern across the target species. This was further reflected in a significant phylogenetic signal across the scorpion phylogeny for the LD50 in mice and in zebrafish. We also provide the first mouse LD50 value for Grosphus grandidieri.
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2. |
- Liu, Shanlin, et al.
(author)
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Ancient and modem genomes unravel the evolutionary history of the rhinoceros family
- 2021
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In: Cell. - : Elsevier. - 0092-8674 .- 1097-4172. ; 184:19, s. 4874-4885.e16
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Journal article (peer-reviewed)abstract
- Only five species of the once-diverse Rhinocerotidae remain, making the reconstruction of their evolutionary history a challenge to biologists since Darwin. We sequenced genomes from five rhinoceros species (three extinct and two living), which we compared to existing data from the remaining three living species and a range of outgroups. We identify an early divergence between extant African and Eurasian lineages, resolving a key debate regarding the phylogeny of extant rhinoceroses. This early Miocene (similar to 16 million years ago [mya]) split post-dates the land bridge formation between the Afro-Arabian and Eurasian landmasses. Our analyses also show that while rhinoceros genomes in general exhibit low levels of genome-wide diversity, heterozygosity is lowest and inbreeding is highest in the modern species. These results suggest that while low genetic diversity is a long-term feature of the family, it has been particularly exacerbated recently, likely reflecting recent anthropogenic-driven population declines.
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3. |
- Pečnerová, Patrícia, et al.
(author)
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Population genomics of the muskox' resilience in the near absence of genetic variation
- 2024
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In: Molecular Ecology. - 0962-1083 .- 1365-294X. ; 33:2
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Journal article (peer-reviewed)abstract
- Genomic studies of species threatened by extinction are providing crucial information about evolutionary mechanisms and genetic consequences of population declines and bottlenecks. However, to understand how species avoid the extinction vortex, insights can be drawn by studying species that thrive despite past declines. Here, we studied the population genomics of the muskox (Ovibos moschatus), an Ice Age relict that was at the brink of extinction for thousands of years at the end of the Pleistocene yet appears to be thriving today. We analysed 108 whole genomes, including present-day individuals representing the current native range of both muskox subspecies, the white-faced and the barren-ground muskox (O. moschatus wardi and O. moschatus moschatus) and a ~21,000-year-old ancient individual from Siberia. We found that the muskox' demographic history was profoundly shaped by past climate changes and post-glacial re-colonizations. In particular, the white-faced muskox has the lowest genome-wide heterozygosity recorded in an ungulate. Yet, there is no evidence of inbreeding depression in native muskox populations. We hypothesize that this can be explained by the effect of long-term gradual population declines that allowed for purging of strongly deleterious mutations. This study provides insights into how species with a history of population bottlenecks, small population sizes and low genetic diversity survive against all odds.
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4. |
- Baas, Pauline, et al.
(author)
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Population-level assessment of genetic diversity and habitat fragmentation in critically endangered Grauer's gorillas
- 2018
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In: American Journal of Physical Anthropology. - : Wiley. - 0002-9483 .- 1096-8644. ; 165:3, s. 565-575
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Journal article (peer-reviewed)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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5. |
- Barcala, Maximiliano Estravis, et al.
(author)
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Whole-genome resequencing facilitates the development of a 50K single nucleotide polymorphism genotyping array for Scots pine (Pinus sylvestris L.) and its transferability to other pine species
- 2024
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In: The Plant Journal. - 0960-7412 .- 1365-313X. ; 117:3, s. 944-955
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Journal article (peer-reviewed)abstract
- Scots pine (Pinus sylvestris L.) is one of the most widespread and economically important conifer species in the world. Applications like genomic selection and association studies, which could help accelerate breeding cycles, are challenging in Scots pine because of its large and repetitive genome. For this reason, genotyping tools for conifer species, and in particular for Scots pine, are commonly based on transcribed regions of the genome. In this article, we present the Axiom Psyl50K array, the first single nucleotide polymorphism (SNP) genotyping array for Scots pine based on whole-genome resequencing, that represents both genic and intergenic regions. This array was designed following a two-step procedure: first, 192 trees were sequenced, and a 430K SNP screening array was constructed. Then, 480 samples, including haploid megagametophytes, full-sib family trios, breeding population, and range-wide individuals from across Eurasia were genotyped with the screening array. The best 50K SNPs were selected based on quality, replicability, distribution across the draft genome assembly, balance between genic and intergenic regions, and genotype–environment and genotype–phenotype associations. Of the final 49 877 probes tiled in the array, 20 372 (40.84%) occur inside gene models, while the rest lie in intergenic regions. We also show that the Psyl50K array can yield enough high-confidence SNPs for genetic studies in pine species from North America and Eurasia. This new genotyping tool will be a valuable resource for high-throughput fundamental and applied research of Scots pine and other pine species.
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6. |
- Brealey, Jaelle C., et al.
(author)
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Dental Calculus as a Tool to Study the Evolution of the Mammalian Oral Microbiome
- 2020
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In: Molecular biology and evolution. - : OXFORD UNIV PRESS. - 0737-4038 .- 1537-1719. ; 37:10, s. 3003-3022
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Journal article (peer-reviewed)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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7. |
- Cortazar-Chinarro, Maria, et al.
(author)
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Antimicrobial peptide and sequence variation along a latitudinal gradient in two anurans
- 2020
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In: BMC Genetics. - : BMC. - 1471-2156. ; 21:1
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Journal article (peer-reviewed)abstract
- Background While there is evidence of both purifying and balancing selection in immune defense genes, large-scale genetic diversity in antimicrobial peptides (AMPs), an important part of the innate immune system released from dermal glands in the skin, has remained uninvestigated. Here we describe genetic diversity at three AMP loci (Temporin, Brevinin and Palustrin) in two ranid frogs (Rana arvalis and R. temporaria) along a 2000 km latitudinal gradient. We amplified and sequenced part of the Acidic Propiece domain and the hypervariable Mature Peptide domain ( 150-200 bp) in the three genes using Illumina Miseq and expected to find decreased AMP genetic variation towards the northern distribution limit of the species similarly to studies on MHC genetic patterns. Results We found multiple loci for each AMP and relatively high gene diversity, but no clear pattern of geographic genetic structure along the latitudinal gradient. We found evidence of trans-specific polymorphism in the two species, indicating a common evolutionary origin of the alleles. Temporin and Brevinin did not form monophyletic clades suggesting that they belong to the same gene family. By implementing codon evolution models we found evidence of strong positive selection acting on the Mature Peptide. We also found evidence of diversifying selection as indicated by divergent allele frequencies among populations and high Theta k values. Conclusion Our results suggest that AMPs are an important source of adaptive diversity, minimizing the chance of microorganisms developing resistance to individual peptides.
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9. |
- Dehasque, Marianne, et al.
(author)
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Temporal dynamics of woolly mammoth genome erosion prior to extinction
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Other publication (other academic/artistic)abstract
- A large number of species have recently recovered from near-extinction events. Understanding the genetic consequences of severe population declines followed by demographic recoveries is key to predict the long-term viability of species in order to mitigate future extinction risks. Although these species have avoided the immediate extinction threat, their long-term viability remains questionable due to the genetic consequences of population declines, which are not understood on a time scale beyond a few generations. The woolly mammoth (Mammuthus primigenius) population on Wrangel Island is an excellent model system to investigate long-term genetic consequences of a population bottleneck. Mammoths became isolated on the island in the early Holocene due to rising sea levels, and persisted for over 200 generations (~6,000 years) before becoming extinct ~4,000 years ago. To study the evolutionary processes leading up to the extinction of the woolly mammoth on the island, we analysed 21 Siberian woolly mammoth genomes, including that of one of the last known mammoths. Our results show that the Wrangel Island mammoths recovered quickly from an initially severe bottleneck, and subsequently remained demographically stable during the ensuing 6 millennia. Further, we find that highly deleterious mutations were gradually purged from the population, whereas there was an accumulation of mildly deleterious mutations. The gradual purging of highly deleterious mutations suggests an ongoing inbreeding depression that lasted for hundreds of generations. This time-lag between demographic and genetic recovery has wide-ranging implications for conservation management of recently bottlenecked present-day populations.
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