THE MAINTENANCE OF SPERM VARIABILITY: CONTEXT‐DEPENDENT SELECTION ON SPERM MORPHOLOGY IN A BROADCAST SPAWNING INVERTEBRATE
THE MAINTENANCE OF SPERM VARIABILITY: CONTEXT‐DEPENDENT SELECTION ON SPERM MORPHOLOGY IN A BROADCAST SPAWNING INVERTEBRATE
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精子变异性的维持：广播产卵无脊椎动物精子形态的环境相关选择
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
D. Marshall
中科院分区：
文献类型：
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作者：
Darren W. Johnson;Keyne Monro;D. Marshall
尽管精子具有独特的关键功能，而且与健康有着密切的关系，但为什么精子如此多变？理解精子形态进化的关键是确定哪些特征使精子能够成功受精。一些精子特征(例如，尾长、总大小)与精子性能有关，但这些特征的益处可能高度依赖于环境。在这里，我们研究了一种广播性产卵管虫(Galeolaria Gemineoa)精子形态的表型选择。我们进行了实验室实验，以测量一系列精子环境中精子的平均形态和相对受精成功率之间的关系，这些环境旨在接近卵子在自然界中遇到的精子浓度和年龄范围。我们发现，多变量选择的强度和形式在我们的环境梯度中有很大的不同。长尾巴和小头的精子在高浓度环境中更受欢迎，而长头精子在低浓度和老年时更受欢迎。我们认为，当地受精环境的变化和由此导致的选择差异可以保持男性内部和男性之间精子形态的差异性。
Why are sperm so variable despite having a singular, critical function and an intimate relationship with fitness? A key to understanding the evolution of sperm morphology is identifying which traits enable sperm to be successful fertilizers. Several sperm traits (e.g., tail length, overall size) are implicated in sperm performance, but the benefits of these traits are likely to be highly context dependent. Here, we examined phenotypic selection on sperm morphology of a broadcast spawning tube worm (Galeolaria gemineoa). We conducted laboratory experiments to measure the relationship between average sperm morphology and relative fertilization success across a range of sperm environments that were designed to approximate the range of sperm concentrations and ages encountered by eggs in nature. We found that the strength and form of multivariate selection varied substantially across our environmental gradients. Sperm with long tails and small heads were favored in high‐concentration environments, whereas sperm with long heads were favored at low concentrations and old ages. We suggest variation in the local fertilization environment and resulting differences in selection can preserve variability in sperm morphology both within and among males.