A gene-based model of fitness and its implications for genetic variation: Genetic and inbreeding loads

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 21, 2025

Abstract In the companion paper to this, we examined consequences for patterns of linkage disequilibrium “gene” model fitness, which postulates that effects recessive or partially deleterious mutations located at different sites within a gene fail complement each other. Here, examine genetic and inbreeding loads, using both analytical simulation methods, contrast it with frequently used “sites” allows allelic complementation. We show results in slightly lower load, but much smaller than model, implying standard predictions mutational contributions depression may be overestimates. Synergistic epistasis between pairs was also modeled, shown considerably reduce load models. The theoretical are discussed relation data on Drosophila melanogaster .

Language: Английский

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Ancient Demographics Determine the Effectiveness of Genetic Purging in Endangered Lizards

Molecular Biology and Evolution, Journal Year: 2021, Volume and Issue: 39(1)

Published: Dec. 14, 2021

Abstract The purging of deleterious alleles has been hypothesized to mitigate inbreeding depression, but its effectiveness in endangered species remains debatable. To understand how are purged during population contractions, we analyzed genomes the Chinese crocodile lizard (Shinisaurus crocodilurus), which is only surviving family and currently isolated into small populations. Population genomic analyses revealed four genetically distinct conservation units sharp declines both effective size genetic diversity. By comparing relative load across populations conducting simulations, discovered that seriously were effectively contractions this relict species, although generally enhanced burden. However, despite with initial purging, our simulations also predicted will gradually accumulate under prolonged bottlenecking. Therefore, emphasize importance maintaining a minimum capacity increasing functional diversity efforts preserve other species.

Language: Английский

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Mutation load decreases with haplotype age in wild Soay sheep

Evolution Letters, Journal Year: 2021, Volume and Issue: 5(3), P. 187 - 195

Published: May 18, 2021

Runs of homozygosity (ROH) are pervasive in diploid genomes and expose the effects deleterious recessive mutations, but how exactly these regions contribute to variation fitness remains unclear. Here, we combined empirical analyses simulations explore ROH with varying genetic map lengths wild Soay sheep. Using a long-term dataset 4879 individuals genotyped at 417K SNPs, found that inbreeding depression increases length. A 1% genomic increase long (>12.5 cM) reduced odds first-year survival by 12.4% compared only 7.7% for medium (1.56-12.5 cM), whereas short (<1.56 had no effect on survival. We show forward this is predicted: shorter ROH, will have higher densities alleles, larger average lower population frequencies. Taken together, our results consistent idea mutation load decreases older haplotypes underlying where purifying selection has more time purge mutations. Finally, study demonstrates strong can persist despite ongoing purging historically small population.

Language: Английский

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The impact of climate change on the distribution of rare and endangered tree Firmiana kwangsiensis using the Maxent modeling

Ecology and Evolution, Journal Year: 2022, Volume and Issue: 12(8)

Published: July 29, 2022

The upsurge in anthropogenic climate change has accelerated the habitat loss and fragmentation of wild animals plants. rare endangered plants are important biodiversity elements. However, lack comprehensive reliable information on spatial distribution these organisms hampered holistic efficient conservation management measures. We explored consequences geographical

Language: Английский

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Genomic erosion in a demographically recovered bird species during conservation rescue

Conservation Biology, Journal Year: 2022, Volume and Issue: 36(4)

Published: May 12, 2022

The pink pigeon (Nesoenas mayeri) is an endemic species of Mauritius that has made a remarkable recovery after severe population bottleneck in the 1970s to early 1990s. Prior this bottleneck, ex situ was established from which captive-bred individuals were released into free-living subpopulations increase size and genetic variation. This conservation rescue led rapid 400-480 individuals, twice downlisted on International Union for Conservation Nature (IUCN) Red List. We analyzed impacts neutral variation during (1993-2008) with restriction site-associated sequencing, microsatellite analyses, quantitative analysis studbook data 1112 birds zoos Europe United States. used computer simulations study predicted changes viability past future. Genetic declined rapidly, despite rebound, effective approximately order magnitude smaller than census size. carried high load circa 15 lethal equivalents longevity. Our continued inbreeding will likely result increased expression deleterious mutations (i.e., realized load) depression. Without actions, it go extinct wild within 100 years. been instrumental population. However, further required recover lost variation, reduce harmful prevent extinction. use genomics modeling can inform IUCN assessments extinction risk species, helps dependency populations.

Language: Английский

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