Patterns of reproductive isolation within and between two Lygaeus species characterized by sexual conflicts over mating
Patterns of reproductive isolation within and between two Lygaeus species characterized by sexual conflicts over mating
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DOI：
10.1111/bij.12639
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发表时间：
2015-12-01
影响因子：
1.9
通讯作者：
Shuker, David M.
中科院分区：
文献类型：
--
作者：
Evans, Gethin M. V.;Nowlan, Toby;Shuker, David M.
理论表明，在某些情况下，交配上的性别冲突可能会导致种群之间在与交配相关的特征上出现不同的性对抗共同进化，这可能会促进生殖隔离，从而促进物种形成。然而，交配上的性别冲突也可能选择能够增强种群间基因流动、限制种群分化的特征(例如，男性愿意交配)。在目前的研究中，我们比较了交配前和交配后的隔离在两个物种之间的差异，这两个物种的特征是雌雄在交配率上发生冲突。我们量化了从意大利和瑞典收集的五个种子虫种群的性隔离，以及同样从意大利收集的姐妹种Lygaeus Simans种群的两个重复。我们没有发现种群之间存在生殖隔离的证据，这表明交配上的性别冲突并没有导致种群在相关交配性状上的分化。然而，马尾鱼和拟马尾鱼之间存在很强的不对称交配隔离：雄性马尾鱼能够与雌性马尾鱼成功交配，而雄性马尾鱼基本上不能与雌性马尾鱼交配。然而，随着杂交F-2后代的产生，我们几乎没有发现这两个物种之间存在强烈的交配后隔离的证据。我们的结果表明，交配上的性别冲突并没有导致种群分化，实际上可能支持了相反的理论预测，即男性交配意愿可能通过促进基因流动来延缓物种形成。
Theory suggests that, under some circumstances, sexual conflict over mating can lead to divergent sexually antagonistic coevolution among populations for traits associated with mating, and that this can promote reproductive isolation and hence speciation. However, sexual conflict over mating may also select for traits (e.g. male willingness to mate) that enhance gene flow between populations, limiting population divergence. In the present study, we compare pre- and post-mating isolation within and between two species characterized by male-female conflict over mating rate. We quantify sexual isolation among five populations of the seed bug Lygaeus equestris collected from Italy and Sweden, and two replicates of a population of the sister-species Lygaeus simulans, also collected from Italy. We find no evidence of reproductive isolation amongst populations of L.equestris, suggesting that sexual conflict over mating has not led to population divergence in relevant mating traits in L.equestris. However, there was strong asymmetric pre-mating isolation between L.equestris and L.simulans: male L.simulans were able to mate successfully with female L.equestris, whereas male L.equestris were largely unable to mate with female L.simulans. We found little evidence for strong post-mating isolation between the two species, however, with hybrid F-2 offspring being produced. Our results suggest that sexual conflict over mating has not led to population divergence, and indeed perhaps supports the contrary theoretical prediction that male willingness to mate may retard speciation by promoting gene flow.