Quantifying the fraction of new mutations that are recessive lethal

Evolution, Journal Year: 2023, Volume and Issue: 77(7), P. 1539 - 1549

Published: April 19, 2023

Abstract The presence and impact of recessive lethal mutations have been widely documented in diploid outcrossing species. However, precise estimates the proportion new that are remain limited. Here, we evaluate performance Fit∂a∂i, a commonly used method for inferring distribution fitness effects (DFE), mutations. Using simulations, demonstrate both additive cases, inference deleterious nonlethal portion DFE is minimally affected by small (<10%) Additionally, while Fit∂a∂i cannot estimate fraction mutations, can accurately infer Finally, as an alternative approach to lethal, employ models mutation–selection–drift balance using existing genomic parameters segregating lethals humans Drosophila melanogaster. In species, load be explained very (<1%) nonsynonymous being lethal. Our results refute recent assertions much higher (4%–5%), highlighting need additional information on joint selection dominance coefficients.

Language: Английский

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Genome-Assisted Gene-Flow Rescued Genetic Diversity Without Hindering Growth Performance in an Inbred Coho Salmon (Oncorhynchus kisutch) Population Selected for High Growth Phenotype

Marine Biotechnology, Journal Year: 2025, Volume and Issue: 27(1)

Published: Feb. 1, 2025

Abstract Selective breeding is a powerful tool for improving aquaculture production. A well-managed program essential, as populations can otherwise lose genetic diversity, leading to reduced selection response and inbreeding excesses. In such cases, diversity in broodstock must be restored by introducing individuals from external populations. However, this reduce the accumulated gains selective breeding. introduction of with superior phenotypes will allow restoration without sacrificing these gains. study, we demonstrated possibility using selectively bred (SB) randomly (RB) population coho salmon ( Oncorhynchus kisutch ). Forty males growth were selected RB genomic crossed 127 collected females SB population, producing newly (NB) population. Genetic assessed statistics effective number alleles, allele richness, observed heterozygosity 11 microsatellite markers, was higher NB than RB. Additionally, fork length body weight compared among three after 12 months post-fertilization common tanks. The least-squares means similar between (164.9 mm 57.9 g) (161.1 53.7 g), while both significantly greater (150.4 43.0 g). Our results highlight effectiveness genome-assisted gene flow restoring compromising gain growth.

Language: Английский

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A Test of the Long‐Term Efficiency of Genetic Rescue With Drosophila melanogaster

Molecular Ecology, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 18, 2025

ABSTRACT Genetic rescue is considered a promising but underutilised conservation strategy to mitigate inbreeding depression and restore genetic diversity. Yet, empirical evidence supporting its long‐term efficacy limited studies investigating short‐term effects. Here, we conducted an experiment with Drosophila test the efficiency of across generations. A wild population was captured found genetically diverse mass‐bred base (BP) in laboratory. Smaller populations 50 individuals each (N50) were then founded from BP maintained for 31 Three sets lines eight these N50 populations: non‐rescued (control), rescued males, males. These 33 Pupae productivity analysis showed substantial purging adaptation laboratory conditions BP. Rescued‐BP higher lower extinction rates compared lines. Whole‐genome sequencing line rescued‐BP revealed fewer deleterious alleles, diversity, line, suggesting efficient rescue. Our results enlighten importance introducing new variation allowing increase survival even small despite simultaneous introduction load, particularly when facing global changes affecting environmental both donor recipient populations.

Language: Английский

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Can genetic rescue help save Arabia's last big cat?

Evolutionary Applications, Journal Year: 2024, Volume and Issue: 17(5)

Published: May 1, 2024

Abstract Genetic diversity underpins evolutionary potential that is essential for the long‐term viability of wildlife populations. Captive populations harbor genetic potentially lost in wild, which could be valuable release programs and rescue. The Critically Endangered Arabian leopard ( Panthera pardus nimr ) has disappeared from most its former range across Peninsula, with fewer than 120 individuals left an additional 64 leopards captivity. We (i) examine wild captive to identify global patterns structure; (ii) estimate size remaining population Dhofar mountains Oman using spatially explicit capture–recapture models on DNA camera trap data, (iii) explore impact rescue three complementary computer modeling approaches. estimated a 51 (95% CI 32–79) found 8 out 25 microsatellite alleles present eight loci were undetected wild. This includes two only founders known have been wild‐sourced Yemen, suggests this represents important source then assessed benefits reintroducing novel into as well risks elevating load through captive‐bred individuals. Simulations indicate can improve by reducing realized load. model also partly purged population, making it However, greater loss exacerbate genomic erosion during program, these should carefully evaluated. An next step recovery empirically validate conclusions, implement monitor genomics‐informed management plan, optimize strategy tool recover Arabia's last big cat.

Language: Английский

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Strongly deleterious mutations influence reproductive output and longevity in an endangered population

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Sept. 27, 2024

Language: Английский

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Genomes of critically endangered saola are shaped by population structure and purging

Cell, Journal Year: 2025, Volume and Issue: unknown

Published: May 1, 2025

The saola is one of the most elusive large mammals, standing at brink extinction. We constructed a reference genome and resequenced 26 individuals, confirming as basal member Bovini. Despite its small geographic range, we found that partitioned into two populations with high genetic differentiation (FST = 0.49). estimate these diverged started declining 5,000-20,000 years ago, possibly due to climate changes exacerbated by increasing human activities. has long tracts without genomic diversity; however, are not shared populations. Saolas carry load, yet their gradual decline resulted in purging deleterious variation. Finally, find combining populations, e.g., an eventual captive breeding program, would mitigate load increase odds species survival.

Language: Английский

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Genetic purging in captive endangered ungulates with extremely low effective population sizes

Heredity, Journal Year: 2021, Volume and Issue: 127(5), P. 433 - 442

Published: Sept. 28, 2021

Abstract Inbreeding threatens the survival of small populations by producing inbreeding depression, but also exposes recessive deleterious effects in homozygosis allowing for genetic purging. Using inbreeding-purging theory, we analyze early four pedigreed captive breeding programs endangered ungulates where population growth was prioritized so that most adult females were allowed to contribute offspring according their fitness. We find evidence purging can substantially reduce depression Gazella cuvieri (with effective size N e = 14) and Nanger dama ( 11). No is detected Ammotragus lervia 4), agreement with notion drift overcomes under fast inbreeding, nor G. dorcas 39) where, due larger size, slower detection expected require more generations. Thus, although smaller are always show fitness (as well as less adaptive potential) than ones higher fixation, our results a substantial fraction load be purged when contributions governed natural selection. Since management strategies intended maximize ratio from actual tend purging, search compromise between these could beneficial long term. This achieved either some level random mating role selection determining contributions, or undertaking reintroductions into wild at earliest opportunity.

Language: Английский

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Some hope and many concerns on the future of the vaquita

Heredity, Journal Year: 2022, Volume and Issue: 130(4), P. 179 - 182

Published: Nov. 4, 2022

Language: Английский

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Models based on best-available information support a low inbreeding load and potential for recovery in the vaquita

Heredity, Journal Year: 2023, Volume and Issue: 130(4), P. 183 - 187

Published: March 20, 2023

Language: Английский

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Reintroducing genetic diversity in populations from cryopreserved material: the case of Abondance, a French local dairy cattle breed

Genetics Selection Evolution, Journal Year: 2023, Volume and Issue: 55(1)

Published: April 19, 2023

Genetic diversity is a necessary condition for populations to evolve under natural adaptation, artificial selection, or both. However, genetic often threatened, in particular domestic animal where drift and inbreeding are strong. In this context, cryopreserved resources promising option reintroduce lost variants limit inbreeding. while the use of ancient more common plant breeding, it less documented animals due longer generation interval, making difficult fill gap performance continuous selection. This study investigates one only concrete cases available animals, which semen from bull born 1977 lineage was introduced into breeding scheme French local dairy cattle breed, Abondance than 20 years later.We found that re-introduced genetically distinct with respect current population thus allowed part over time be restored. The expected negative milk production selection absorbed few by preferential mating elite cows. Moreover, re-use two decades later did not increase level inbreeding, even tended reduce avoiding relatives. Finally, reintroduction improved reproductive abilities, trait subject past.The material an efficient way manage population, mitigating effects both strong attention should paid disadvantages associated incorporating original material, notably discrepancy values selected traits Therefore, careful characterization cryobanks could help ensure sustainable management populations, small populations. These results also transferred conservation wild threatened

Language: Английский

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