Inbreeding Depression Is Purged in the Invasive Insect Harmonia axyridis
Inbreeding Depression Is Purged in the Invasive Insect Harmonia axyridis
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DOI：
10.1016/j.cub.2011.01.068
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发表时间：
2011-03-08
期刊：
影响因子：
9.2
通讯作者：
Estoup, Arnaud
中科院分区：
文献类型：
--
作者：
Facon, Benoit;Hufbauer, Ruth A.;Estoup, Arnaud
种群规模的瓶颈减少了遗传多样性，增加了近亲繁殖，这可能导致近亲繁殖衰退[1]。因此，令人困惑的是，通常通过瓶颈的引入物种如何成为如此成功的入侵者[2]。然而，在某些理论条件下，中等大小的瓶颈实际上可以清除导致近交衰退的等位基因[3]。虽然这一过程已在模型实验室系统中得到证实[4]，但尚未在自然入侵种群中观察到。我们评估这种清洗是否可以促进生物入侵，通过使用世界范围内的入侵瓢虫（或瓢虫）异色瓢虫。我们首先表明，入侵种群经历了中等强度的瓶颈。然后，我们证明，复制引进人口的经验几乎没有近亲繁殖的本地人口所遭受的抑郁症。因此，瓶颈并不像人们通常认为的那样对入侵构成障碍，而是通过清除有害的等位基因，使入侵者能够进化，即使在近亲繁殖时也能保持高适应度。
Bottlenecks in population size reduce genetic diversity and increase inbreeding, which can lead to inbreeding depression [1]. It is thus puzzling how introduced species, which typically pass through bottlenecks, become such successful invaders [2]. However, under certain theoretical conditions, bottlenecks of intermediate size can actually purge the alleles that cause inbreeding depression [3]. Although this process has been confirmed in model laboratory systems [4], it has yet to be observed in natural invasive populations. We evaluate whether such purging could facilitate biological invasions by using the world-wide invasion of the ladybird (or ladybug) Harmonia axyridis. We first show that invasive populations endured a bottleneck of intermediate intensity. We then demonstrate that replicate introduced populations experience almost none of the inbreeding depression suffered by native populations. Thus, rather than posing a barrier to invasion as often assumed, bottlenecks, by purging deleterious alleles, can enable the evolution of invaders that maintain high fitness even when inbred.