Competition drives cooperation among closely related sperm of deer mice
Competition drives cooperation among closely related sperm of deer mice
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DOI：
10.1038/nature08736
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发表时间：
2010-02-11
期刊：
影响因子：
64.8
通讯作者：
Hoekstra, Hopi E.
中科院分区：
文献类型：
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作者：
Fisher, Heidi S.;Hoekstra, Hopi E.
由精子竞争驱动的非凡适应之一是精子的合作行为(1)。通过形成合作群体，精子可以提高其游动速度，从而在雄性精子竞争中获得优势(1,2)。因此，选择应有利于最密切相关的精子的合作，以最大限度地提高适应性(3)。在这里，我们展示了鹿鼠（Peromyscus）的精子形成运动聚集，然后我们使用该系统来测试精子合作的预测。我们发现精子与同种精子聚集的频率高于与异种精子聚集的频率，这表明单个精子可以根据遗传相关性进行区分。接下来，我们提供证据表明密切相关的精子的合作行为是由精子竞争驱动的。在缺乏精子竞争的一夫一妻制物种（Peromyscus poliionotus）中，精子不加区别地与不相关的同种精子组合在一起。相比之下，在高度混杂的鹿鼠Peromyscus maniculatus中，精子与来自同一雄性的精子聚集的可能性明显高于与来自无关同种供体的精子聚集的可能性。即使当我们测试雄性兄弟姐妹的精子时，我们仍然看到手足蟹中相关精子的优先聚集。这些结果表明，来自杂乱鹿鼠的精子会区分亲属，从而与关系最密切的精子合作，这种适应可能是由精子竞争驱动的。
Among the extraordinary adaptations driven by sperm competition is the cooperative behaviour of spermatozoa(1). By forming cooperative groups, sperm can increase their swimming velocity and thereby gain an advantage in intermale sperm competition(1,2). Accordingly, selection should favour cooperation of the most closely related sperm to maximize fitness(3). Here we show that sperm of deer mice (genus Peromyscus) form motile aggregations, then we use this system to test predictions of sperm cooperation. We find that sperm aggregate more often with conspecific than heterospecific sperm, suggesting that individual sperm can discriminate on the basis of genetic relatedness. Next, we provide evidence that the cooperative behaviour of closely related sperm is driven by sperm competition. In a monogamous species lacking sperm competition, Peromyscus polionotus, sperm indiscriminately group with unrelated conspecific sperm. In contrast, in the highly promiscuous deer mouse, Peromyscus maniculatus, sperm are significantly more likely to aggregate with those obtained from the same male than with sperm from an unrelated conspecific donor. Even when we test sperm from sibling males, we continue to see preferential aggregations of related sperm in P. maniculatus. These results suggest that sperm from promiscuous deer mice discriminate among relatives and thereby cooperate with the most closely related sperm, an adaptation likely to have been driven by sperm competition.