Strongly deleterious mutations are a primary determinant of extinction risk due to inbreeding depression.
Strongly deleterious mutations are a primary determinant of extinction risk due to inbreeding depression.
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强烈有害的突变是由于近交抑郁症引起的灭绝风险的主要决定因素。
DOI：
10.1002/evl3.209
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发表时间：
2021-03
影响因子：
5
通讯作者：
Lohmueller KE
中科院分区：
文献类型：
--
作者：
Kyriazis CC;Wayne RK;Lohmueller KE
人类驱动的栖息地碎片化和丧失导致了具有高灭绝风险的小型和孤立的动植物种群的激增。这些种群面临灭绝的主要威胁之一是近亲繁殖衰退，这主要是由于近亲繁殖导致隐性有害突变变纯合子造成的。管理这些种群的典型方法是保持高度的遗传多样性，越来越多地通过从大量种群中转移个体来发起“基因拯救”。然而，这种方法的局限性最近在皇家岛上的灰狼种群的消亡中突显出来，在大量大陆狼种群的迁徙到来后不久，灰狼种群就下降到了灭绝的边缘。在这里，我们使用一个新的种群遗传模拟框架来研究遗传多样性、有害变异和人口历史在调节小种群近亲繁殖衰退导致的灭绝风险中所起的作用。我们表明，在现实的显性模型下，由于这些突变被隐藏在杂合态中的选择之外，大量的种群蕴藏着高水平的隐性强有害变异。因此，当大量种群收缩时，在这些极具危害性的突变通过近亲繁殖暴露出来后，他们经历的灭绝风险大大增加。此外，我们证明，尽管基因拯救作为一种降低灭绝风险的手段广泛有效，但由于较小的种群具有较低水平的隐性强有害变异，因此通过吸引来自中小型来源种群的迁徙而不是来自大型来源种群的迁徙，其有效性可以大大提高。我们的发现挑战了传统的保护范式，这种范式侧重于在小种群中最大化遗传多样性，而支持一种强调最大限度减少有害变异的观点。这些见解对管理人类世日益碎片化的小而孤立的人口具有重要意义。
Human‐driven habitat fragmentation and loss have led to a proliferation of small and isolated plant and animal populations with high risk of extinction. One of the main threats to extinction in these populations is inbreeding depression, which is primarily caused by recessive deleterious mutations becoming homozygous due to inbreeding. The typical approach for managing these populations is to maintain high genetic diversity, increasingly by translocating individuals from large populations to initiate a “genetic rescue.” However, the limitations of this approach have recently been highlighted by the demise of the gray wolf population on Isle Royale, which declined to the brink of extinction soon after the arrival of a migrant from the large mainland wolf population. Here, we use a novel population genetic simulation framework to investigate the role of genetic diversity, deleterious variation, and demographic history in mediating extinction risk due to inbreeding depression in small populations. We show that, under realistic models of dominance, large populations harbor high levels of recessive strongly deleterious variation due to these mutations being hidden from selection in the heterozygous state. As a result, when large populations contract, they experience a substantially elevated risk of extinction after these strongly deleterious mutations are exposed by inbreeding. Moreover, we demonstrate that, although genetic rescue is broadly effective as a means to reduce extinction risk, its effectiveness can be greatly increased by drawing migrants from small or moderate‐sized source populations rather than large source populations due to smaller populations harboring lower levels of recessive strongly deleterious variation. Our findings challenge the traditional conservation paradigm that focuses on maximizing genetic diversity in small populations in favor of a view that emphasizes minimizing strongly deleterious variation. These insights have important implications for managing small and isolated populations in the increasingly fragmented landscape of the Anthropocene.
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DOI：
10.1073/pnas.1619508114
发表时间：
2017-04-25
影响因子：
11.1
作者：
Huber, Christian D.;Kim, Bernard Y.;Lohmueller, Kirk E.
通讯作者：
Lohmueller, Kirk E.
影响因子：
4.9
作者：
Frankham, Richard
通讯作者：
Frankham, Richard
DOI：
10.1098/rspb.2006.3477
发表时间：
2006-06-22
影响因子：
4.7
作者：
Hogg, John T.;Forbes, Stephen H.;Luikart, Gordon
通讯作者：
Luikart, Gordon
影响因子：
16.6
作者：
Huber CD;Durvasula A;Hancock AM;Lohmueller KE
通讯作者：
Lohmueller KE
影响因子：
9.2
作者：
Fitzpatrick, Sarah W.;Bradburd, Gideon S.;Funk, W. Chris
通讯作者：
Funk, W. Chris