Genetic rescue of small inbred populations: meta-analysis reveals large and consistent benefits of gene flow
Genetic rescue of small inbred populations: meta-analysis reveals large and consistent benefits of gene flow
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DOI：
10.1111/mec.13139
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发表时间：
2015-06-01
影响因子：
4.9
通讯作者：
Frankham, Richard
中科院分区：
文献类型：
--
作者：
Frankham, Richard
许多物种呈碎片化分布，孤立的小种群遭受近交衰退和/或进化能力下降。如果没有来自该物种内其他种群的基因流（遗传拯救），这些种群很可能会灭绝。然而，出于保护目的而进行的此类杂交仅有约20例已发表的案例，可能在潜在受益的种群中所占比例极低。由于遗传拯救的一个障碍是缺乏对野生物种中遗传拯救效应的程度和一致性的综述，我进行了一项荟萃分析。对近交种群进行杂交，在筛选出的156例远交衰退风险较低的案例中，92.9%产生了有益效果。杂交后综合适合度（繁殖力和存活率相结合）在恶劣环境中的中位数增长为148%，在良好环境中为45%。适合度收益也随着母本近交系数F（因基因流导致的近交系数降低）以及自然远交物种相对于近交物种而显著增加。然而，无脊椎动物、脊椎动物和植物之间的收益没有显著差异。近交种群中适合度性状的进化潜力也受益于基因流。只要潜在杂交的远交衰退风险较低，对自然远交物种的近交种群进行杂交以进行遗传拯救的广泛应用就没有科学障碍。我为遗传拯救尝试的管理提供了修订后的指导方针。
Many species have fragmented distribution with small isolated populations suffering inbreeding depression and/or reduced ability to evolve. Without gene flow from another population within the species (genetic rescue), these populations are likely to be extirpated. However, there have been only similar to 20 published cases of such outcrossing for conservation purposes, probably a very low proportion of populations that would potentially benefit. As one impediment to genetic rescues is the lack of an overview of the magnitude and consistency of genetic rescue effects in wild species, I carried out a meta-analysis. Outcrossing of inbred populations resulted in beneficial effects in 92.9% of 156 cases screened as having a low risk of outbreeding depression. The median increase in composite fitness (combined fecundity and survival) following outcrossing was 148% in stressful environments and 45% in benign ones. Fitness benefits also increased significantly with maternal F (reduction in inbreeding coefficient due to gene flow) and for naturally outbreeding versus inbreeding species. However, benefits did not differ significantly among invertebrates, vertebrates and plants. Evolutionary potential for fitness characters in inbred populations also benefited from gene flow. There are no scientific impediments to the widespread use of outcrossing to genetically rescue inbred populations of naturally outbreeding species, provided potential crosses have a low risk of outbreeding depression. I provide revised guidelines for the management of genetic rescue attempts.