Sperm swimming speed and energetics vary with sperm competition risk in bluegill (Lepomis macrochirus)
Sperm swimming speed and energetics vary with sperm competition risk in bluegill (Lepomis macrochirus)
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DOI：
10.1007/s00265-003-0752-7
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发表时间：
2004-05-01
影响因子：
2.3
通讯作者：
Montgomerie, R
中科院分区：
文献类型：
--
作者：
Burness, G;Casselman, SJ;Montgomerie, R
在精子竞争下，男性受精的成功在很大程度上取决于竞争男性的射精特征。理论模型预测，在外部肥料中，精子竞争的风险增加应该会导致选择更快的精子游泳速度。为了验证这一预测，我们研究了来自父母和运动鞋雄性蓝鳃(Lepomis Macchirus)的精子的行为，这种鱼的特征是由于雄性(父母和绿帽子)的替代生殖策略而具有高水平的绿帽子。因为戴绿帽子的人(运动鞋和卫星)总是在双亲雄性的在场的情况下产卵，但情况并非如此，戴绿帽子的人面临着更大的精子竞争风险。我们在这里表明，运动鞋的精子比亲本雄性的精子具有更快的初始游泳速度，但运动周期更短。此外，我们还发现，精子在激活后不久(大多数受精发生时)的游泳速度与精子中开始的ATP水平相关，这表明精子竞争选择了运动鞋精子中更高的能量容量。因此，运动鞋精子的能量能力和初始游泳速度更高，这可能解释了为什么运动鞋每次射精的精子比父母少，但当运动鞋竞争让一群卵子受精时，它们会比父母的雄性受精更多的卵子。
Under sperm competition, a male's fertilization success depends largely on the ejaculate characteristics of competing males. Theoretical models predict that, in external fertilizers, increased risk of sperm competition should result in selection for increased sperm swimming speed. To test this prediction, we studied the behavior of sperm from parental and sneaker male bluegill (Lepomis macrochirus), a fish species characterized by high levels of cuckoldry due to alternative reproductive tactics of males (parentals and cuckolders). Because cuckolders (sneakers and satellites) always spawn in the presence of a parental male, but the reverse is not true, cuckolders experience the greater risk of sperm competition. We show here that the spermatozoa of sneakers have faster initial swimming speeds but shorter periods of motility than the sperm of parental males. Moreover, we show that sperm swimming speeds shortly after activation (when most fertilization occurs) are correlated with starting ATP levels in spermatozoa, suggesting that sperm competition has selected for higher energetic capacity in the sperm of sneakers. Thus, the higher energetic capacity and initial swimming speed of sneaker sperm may explain why, despite having fewer sperm per ejaculate than parentals, sneakers fertilize more eggs than parental males when they compete to fertilize a clutch of eggs.