The dynamics of sperm cooperation in a competitive environment.
The dynamics of sperm cooperation in a competitive environment.
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DOI：
10.1098/rspb.2014.0296
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发表时间：
2014-09-07
期刊：
影响因子：
--
通讯作者：
Mahadevan L
中科院分区：
文献类型：
--
作者：
Fisher HS;Giomi L;Hoekstra HE;Mahadevan L
精子合作已经在各种分类群中进化，通常被认为是对精子竞争的反应，但这种集体运动形式的好处仍然不清楚。在这里，我们使用精细尺度的成像和最小的数学模型来研究精子聚集在啮齿动物属Peromyscus。我们证明，随着精子细胞的数量在一个聚合体中的增加，该集团移动更持久的线性，但没有增加速度。然而，这种好处在更大的聚集体中被抵消，因为群体的几何形状迫使精子彼此游泳。结果是聚集体大小和平均速度之间的非单调关系，理论预测和经验观察到的最佳值为每个聚集体6至7个精子。为了了解性选择在驱动这些精子群动态中的作用，我们比较了两个具有不同交配系统的姐妹物种。我们发现，Peromyscus maniculatus（高度滥交），这已经在激烈的竞争下进化的精子，形成最佳大小的聚集体往往比Peromyscus polionotus（严格一夫一妻制），缺乏竞争的精子。我们结合数学和实验研究协调精子运动揭示了几何形状，运动和组大小对精子速度的重要性，并建议这些物理变量如何与进化选择压力相互作用，以调节竞争环境中的合作。
Sperm cooperation has evolved in a variety of taxa and is often considered a response to sperm competition, yet the benefit of this form of collective movement remains unclear. Here, we use fine-scale imaging and a minimal mathematical model to study sperm aggregation in the rodent genus Peromyscus. We demonstrate that as the number of sperm cells in an aggregate increase, the group moves with more persistent linearity but without increasing speed. This benefit, however, is offset in larger aggregates as the geometry of the group forces sperm to swim against one another. The result is a non-monotonic relationship between aggregate size and average velocity with both a theoretically predicted and empirically observed optimum of six to seven sperm per aggregate. To understand the role of sexual selection in driving these sperm group dynamics, we compared two sister-species with divergent mating systems. We find that sperm of Peromyscus maniculatus (highly promiscuous), which have evolved under intense competition, form optimal-sized aggregates more often than sperm of Peromyscus polionotus (strictly monogamous), which lack competition. Our combined mathematical and experimental study of coordinated sperm movement reveals the importance of geometry, motion and group size on sperm velocity and suggests how these physical variables interact with evolutionary selective pressures to regulate cooperation in competitive environments.
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影响因子：
2.3
作者：
Burness, G;Casselman, SJ;Montgomerie, R
通讯作者：
Montgomerie, R
影响因子：
3.7
作者：
Immler, Simone;Moore, Harry D. M.;Birkhead, Tim R.
通讯作者：
Birkhead, Tim R.
影响因子：
1.8
作者：
Elgeti, Jens;Gompper, Gerhard
通讯作者：
Gompper, Gerhard
DOI：
10.1073/pnas.0809990106
发表时间：
2009-01-27
影响因子：
11.1
作者：
Fitzpatrick, John L.;Montgomerie, Robert;Balshine, Sigal
通讯作者：
Balshine, Sigal
影响因子：
2
作者：
Couzin, ID;Krause, J;Franks, NR
通讯作者：
Franks, NR