Hunter F M, Birkhead T R
Department of Animal and Plant Sciences, University of Sheffield, S10 2TN, Sheffield, United Kingdom.
Curr Biol. 2002 Jan 22;12(2):121-3. doi: 10.1016/s0960-9822(01)00647-9.
Sperm quality plays an important role in vertebrates in determining which male has the advantage when two or more males compete to fertilize a female's ova. In insects, however, the importance of sperm quality has never been considered, despite sperm competition being widespread and well studied in this group. We tested the hypothesis that sperm viability, measured as the proportion of live sperm, covaried with the intensity of sperm competition in insects. In a pairwise comparison of seven closely related species pairs, each comprising a monandrous and a polyandrous species (i.e., with and without sperm competition, respectively), we found that in all cases the polyandrous species had a higher proportion of live sperm in their sperm stores. The distribution of the percentage of live sperm showed considerable inter- and intraspecific variation, suggesting that, all else being equal, males will vary in their ability to fertilize ova on the basis of sperm viability alone. Our results suggest that sperm viability is one of a suite of male adaptations to sperm competition in insects.
在脊椎动物中，当两个或更多雄性竞争使雌性卵子受精时，精子质量在决定哪个雄性具有优势方面起着重要作用。然而，在昆虫中，尽管精子竞争在该类群中广泛存在且已得到充分研究，但精子质量的重要性从未被考虑过。我们检验了这样一个假设：以活精子比例衡量的精子活力与昆虫精子竞争的强度相关。在对七个密切相关的物种对进行的成对比较中，每个物种对都包括一个单配偶制物种和一个多配偶制物种（即分别有无精子竞争），我们发现在所有情况下，多配偶制物种的精子储存中活精子的比例更高。活精子百分比的分布显示出相当大的种间和种内变异，这表明在其他条件相同的情况下，雄性仅基于精子活力使卵子受精的能力就会有所不同。我们的结果表明，精子活力是昆虫雄性对精子竞争的一系列适应性之一。
