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Fitness decline under osmotic stress in Caenorhabditis elegans populations subjected to spontaneous mutation accumulation at varying population sizes
被引:15
|作者:
Katju, Vaishali
[1
]
Packard, Lucille B.
[2
]
Keightley, Peter D.
[3
]
机构:
[1] Texas A&M Univ, Dept Vet Integrat Biosci, College Stn, TX 77843 USA
[2] Univ New Mexico, Dept Biol, Albuquerque, NM 87131 USA
[3] Univ Edinburgh, Inst Evolutionary Biol, Edinburgh EH9 3JT, Midlothian, Scotland
来源:
基金:
美国国家科学基金会;
美国国家卫生研究院;
关键词:
Conservation;
deleterious mutation;
fitness;
osmotic stress;
productivity;
survivorship to adulthood;
DROSOPHILA-MELANOGASTER;
DELETERIOUS MUTATIONS;
RATES;
EXTINCTION;
TRAITS;
D O I:
10.1111/evo.13463
中图分类号:
Q14 [生态学(生物生态学)];
学科分类号:
071012 ;
0713 ;
摘要:
The consequences of mutations for population fitness depends on their individual selection coefficients and the effective population size. An earlier study of Caenorhabditis elegans spontaneous mutation accumulation lines evolved for 409 generations at three population sizes found thatN(e) = 1 populations declined significantly in fitness whereas the fitness of larger populations (N-e = 5, 50) was indistinguishable from the ancestral control under benign conditions. To test if larger MA populations harbor a load of cryptic deleterious mutations that are obscured underbenignlaboratory conditions, we measured fitness underosmotic stressvia exposure to hypersaline conditions. The fitness ofN(e) = 1 lines exhibited a further decline under osmotic stress compared to benign conditions. However, the fitness of larger populations remained indistinguishable from that of the ancestral control. The average effects of deleterious mutations inN(e) = 1 lines were estimated to be 22% for productivity and 14% for survivorship, exceeding values previously detected underbenignconditions. Our results suggest that fitness decline is due to large effect mutations that are rapidly removed via selection even in small populations, with implications for conservation practices. Genetic stochasticity may not be as potent and immediate a threat to the persistence of small populations as other demographic and environmental stochastic factors.
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页码:1000 / 1008
页数:9
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