| 1. |
- Hansson, Bengt, et al.
(författare)
-
Comment on “Individual heterozygosity predicts translocation success in threatened desert tortoises”
- 2021
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 372:6546
-
Tidskriftsartikel (refereegranskat)abstract
- Scott et al. (Reports, 27 November 2020, p. 1086) bring much-needed attention to species conservation by demonstrating heterozygote superiority among translocated tortoises. However, we believe that their recommended heterozygosity decision rule risks taking conservation genomics backward. We argue that their advice could misguide conservation management aimed at establishing viable populations, and that it can be improved by also assessing the genetic load.
|
|
| 2. |
- Pinto, Alessandro V., et al.
(författare)
-
The impact of habitat loss and population fragmentation on genomic erosion
-
Ingår i: Conservation Genetics. - 1566-0621.
-
Tidskriftsartikel (refereegranskat)abstract
- Habitat loss and population fragmentation pose severe threats to biodiversity and the survival of many species. Population isolation and the decline in effective population size lead to increased genetic drift and inbreeding. In turn, this reduces neutral diversity, and it also affects the genetic load of deleterious mutations. Here, we analyse the effect of such genomic erosion by designing a spatially explicit, individual based model in SLiM, simulating the effects of the recorded habitat loss in Mauritius over the past ~ 250 years. We show that the loss of neutral diversity (genome-wide heterozygosity) was barely noticeable during the first 100 years of habitat loss. Changes to the genetic load took even more time to register, and they only became apparent circa 200 years after the start of habitat decline. Although a considerable number of deleterious mutations were lost by drift, others increased in frequency. The masked load was thus converted into a realised load, which compromised individual fitness and population viability after much of the native habitat had been lost. Importantly, genomic erosion continued after the metapopulation had stabilised at low numbers. Our study shows that historic habitat loss can pose a sustained threat to populations also in future generations, even without further habitat loss. The UN’s Decade on Ecosystem Restoration needs to lead to transformative change to save species from future extinction, and this requires the urgent restoration of natural habitats.
|
|
| 3. |
- Stephenson, Jessica F., et al.
(författare)
-
A further cost for the sicker sex? : Evidence for male-biased parasite-induced vulnerability to predation
- 2016
-
Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 6:8, s. 2506-2515
-
Tidskriftsartikel (refereegranskat)abstract
- Males are typically the sicker sex. Data from multiple taxa indicate that they are more likely to be infected with parasites, and are less "tolerant," or less able to mitigate the fitness costs of a given infection, than females. One cost of infection for many animals is an increased probability of being captured by a predator. A clear, hitherto untested, prediction is therefore that this parasite-induced vulnerability to predation is more pronounced among males than females. We tested this prediction in the sexually size dimorphic guppy, Poecilia reticulata, in which females are typically larger than males. We either sham or experimentally infected guppies with Gyrodactylus turnbulli, elicited their escape response using an established protocol and measured the distance they covered during 60 ms. To discriminate between the effects of body size and those of other inherent sex differences, we size-matched fish across treatment groups. Infection with G. turnbulli reduced the distance covered during the escape response of small adults by 20.1%, whereas that of large fish was unaffected. This result implies that parasite-induced vulnerability to predation is male-biased in the wild: although there was no difference in escape response between our experimentally size-matched groups of males and females, males are significantly smaller across natural guppy populations. These results are consistent with Bateman's principle for immunity: Natural selection for larger body sizes and longevity in females seems to have resulted in the evolution of increased infection tolerance. We discuss the potential implications of sex-and size-biased parasite-induced vulnerability to predation for the evolutionary ecology of this host-parasite interaction in natural communities.
|
|
| 4. |
- Svensson, Ola, 1971-, et al.
(författare)
-
Data from: The genetics of mate preferences in hybrids between two young and sympatric Lake Victoria cichlid species
- 2017
-
Annan publikationabstract
- The genetic architecture of mate preferences is likely to affect significant evolutionary processes, including speciation and hybridization. Here, we investigate laboratory hybrids between a pair of sympatric Lake Victoria cichlid fish species that appear to have recently evolved from a hybrid population between similar predecessor species. The species demonstrate strong assortative mating in the laboratory, associated with divergent male breeding coloration (red dorsum versus blue). We show in a common garden experiment, using DNA-based paternity testing, that the strong female mate preferences among males of the two species are fully recovered in a large fraction of their F2 hybrid generation. Individual hybrid females often demonstrated consistent preferences in multiple mate choice trials (more than or equal to five) across a year or more. This result suggests that female mate preference is influenced by relatively few major genes or genomic regions. These preferences were not changed by experience of a successful spawning event with a male of the non-preferred species in a no-choice single-male trial. We found no evidence for imprinting in the F2 hybrids, although the F1 hybrid females may have been imprinted on their mothers. We discuss this nearly Mendelian inheritance of consistent innate mate preferences in the context of speciation theory.
|
|
| 5. |
- Svensson, Ola, 1971-, et al.
(författare)
-
Immigrant reproductive dysfunction facilitates ecological speciation
- 2017
-
Ingår i: Evolution. - : Wiley-Blackwell. - 0014-3820 .- 1558-5646. ; 71:10, s. 2510-2521
-
Tidskriftsartikel (refereegranskat)abstract
- The distributions of species are not only determined by where they can survive - they must also be able to reproduce. Although immigrant inviability is a well-established concept, the fact that immigrants also need to be able to effectively reproduce in foreign environments has not been fully appreciated in the study of adaptive divergence and speciation. Fertilization and reproduction are sensitive life history stages that could be detrimentally affected for immigrants in non-native habitats. We propose that 'immigrant reproductive dysfunction' is a hitherto overlooked aspect of reproductive isolation caused by natural selection on immigrants. This idea is supported by results from experiments on an externally fertilizing fish (sand goby, Pomatoschistus minutus). Growth and condition of adults were not affected by non-native salinity whereas males spawning as immigrants had lower sperm motility and hatching success than residents. We interpret these results as evidence for local adaptation or acclimation of sperm, and possibly also components of paternal care. The resulting loss in fitness, which we call 'immigrant reproductive dysfunction', has the potential to reduce gene flow between populations with locally adapted reproduction, and it may play a role in species distributions and speciation.
|
|
| 6. |
- Svensson, Ola, 1971, et al.
(författare)
-
Segregation of species-specific male attractiveness in F2 hybrid Lake Malawi cichlid fish
- 2011
-
Ingår i: International Journal of Evolutionary Biology. - : Hindawi Limited. - 2090-052X. ; 2011
-
Tidskriftsartikel (refereegranskat)abstract
- Among the huge radiations of haplochromine cichlid fish in Lakes Malawi and Victoria, closely related species are often reproductively isolated via female mate choice although viable fertile hybrids can be produced when females are confined only with heterospecific males. We generated F2 hybrid males from a cross between a pair of closely related sympatric cichlid fish from Lake Malawi. Laboratory mate choice experiments using microsatellite paternity analysis demonstrated that F2 hybrid males differed significantly in their attractiveness to females of the two parental species, indicating heritable variation in traits involved in mate choice that may contribute to reproductive isolation between these species. We found no significant correlation between male mating success and any measurement of male colour pattern. A simple quantitative genetic model of reproductive isolation suggests that there may be as few as two chromosomal regions controlling species-specific attractiveness. We propose that adaptive radiation of Lake Malawi cichlids could be facilitated by the presence of genes with major effects on mate choice and reproductive isolation.
|
|
| 7. |
- Svensson, Ola, 1971-, et al.
(författare)
-
The genetics of mate preferences in hybrids between two young and sympatric Lake Victoria cichlid species.
- 2017
-
Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 284:1849
-
Tidskriftsartikel (refereegranskat)abstract
- The genetic architecture of mate preferences is likely to affect significant evolutionary processes, including speciation and hybridization. Here, we investigate laboratory hybrids between a pair of sympatric Lake Victoria cichlid fish species that appear to have recently evolved from a hybrid population between similar predecessor species. The species demonstrate strong assortative mating in the laboratory, associated with divergent male breeding coloration (red dorsum versus blue). We show in a common garden experiment, using DNA-based paternity testing, that the strong female mate preferences among males of the two species are fully recovered in a large fraction of their F2 hybrid generation. Individual hybrid females often demonstrated consistent preferences in multiple mate choice trials (more than or equal to five) across a year or more. This result suggests that female mate preference is influenced by relatively few major genes or genomic regions. These preferences were not changed by experience of a successful spawning event with a male of the non-preferred species in a no-choice single-male trial. We found no evidence for imprinting in the F2 hybrids, although the F1 hybrid females may have been imprinted on their mothers. We discuss this nearly Mendelian inheritance of consistent innate mate preferences in the context of speciation theory.
|
|
| 8. |
- Tesson, Sylvie V.M., et al.
(författare)
-
Mendelian Inheritance Pattern and High Mutation Rates of Microsatellite Alleles in the Diatom Pseudo-nitzschia multistriata.
- 2012
-
Ingår i: Protist. - : Elsevier BV. - 1434-4610.
-
Tidskriftsartikel (refereegranskat)abstract
- The diatom Pseudo-nitzschia multistriata exhibits a diplontic life cycle composed of an extensive phase of vegetative cell division and a brief phase of sexual reproduction. To explore genotypic stability, we genotyped seven polymorphic microsatellite loci in 26 monoclonal strains over 3-16 months in a culture maintenance regime. Moreover, to assess inheritance patterns of the microsatellite alleles, we genotyped 246 F1 strains resulting from four mating experiments between parental strains of know genotype. Results generally conformed expectations according to Mendelian inheritance patterns, but deviations were detected indicating mutations during sexual reproduction. A total of forty-two mutations were detected in the clonal cultures over time. Microsatellites with more core-repeats accumulated mutations faster. The mutation rate varied significantly across loci and strains. A binomial mass function and a computer simulation showed that the mutation rate was significantly higher during the first months of culture (μ≈3×10(-3) per locus per cell division) and decreased to μ≈1×10(-3) in the strains kept for 16 months. Our results suggest that genetic mutations acquired in both the vegetative phase and sexual reproduction add to the allelic diversity of microsatellites, and hence to the genotypic variation present in a natural population.
|
|
| 9. |
- Urban, Lara, et al.
(författare)
-
Real-time genomics for One Health
- 2023
-
Ingår i: Molecular Systems Biology. - 1744-4292. ; 19:8
-
Forskningsöversikt (refereegranskat)abstract
- The ongoing degradation of natural systems and other environmental changes has put our society at a crossroad with respect to our future relationship with our planet. While the concept of One Health describes how human health is inextricably linked with environmental health, many of these complex interdependencies are still not well-understood. Here, we describe how the advent of real-time genomic analyses can benefit One Health and how it can enable timely, in-depth ecosystem health assessments. We introduce nanopore sequencing as the only disruptive technology that currently allows for real-time genomic analyses and that is already being used worldwide to improve the accessibility and versatility of genomic sequencing. We showcase real-time genomic studies on zoonotic disease, food security, environmental microbiome, emerging pathogens, and their antimicrobial resistances, and on environmental health itself – from genomic resource creation for wildlife conservation to the monitoring of biodiversity, invasive species, and wildlife trafficking. We stress why equitable access to real-time genomics in the context of One Health will be paramount and discuss related practical, legal, and ethical limitations.
|
|
