Sexual selection and mating advantages in the giant sperm species, Drosophila bifurca -: art. no. 10
Sexual selection and mating advantages in the giant sperm species, Drosophila bifurca -: art. no. 10
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DOI：
10.1093/jis/5.1.10
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发表时间：
2005-04-13
影响因子：
2.2
通讯作者：
Joly, D
中科院分区：
文献类型：
--
作者：
Luck, N;Joly, D
雌雄皆可选择配偶；然而，雌性通常比雄性更挑剔，因为它们在配子上投入更多。女性的选择往往是基于直接的好处，例如更好的生殖产出，而男性的选择似乎是基于女性生育能力的差异。然而，当配子产量有限时，性选择理论预测，配偶选择将对两性的生殖成功起决定性作用。在这里，我们研究如何在双果蝇中获得交配优势，这是一个巨大的精子物种，在这种物种中，两性只产生几个配子。我们最初的预期是：(1)女性会歧视精子枯竭的男性，以避免生育成本；(2)男性会歧视受精的女性，以减少精子竞争，并增加单个配子的父权保证。在21摄氏度的温度下，雄性在22天后达到的性成熟，以及两性的生殖史(女性受精与处女，男性耗尽精子与携带精子)的求偶行为的差异被分析。我们的结果表明：(1)性不成熟阻碍了两性的交配；(2)处女不区分精子丰富和精子枯竭的男性；(3)男性优先与处女交配，因为受精的女性抵挡了男性，这往往会结束男性的求爱。女性的保留是有限的，但当第一个男性精子枯竭时，女性的保留显著增加。与我们最初的预期相反，这些发现表明，男性精子枯竭并不影响女性的交配偏好，而男性求爱的成功是由女性的行为驱动的。本文还讨论了雌性生殖仅在低精子传输率时才被促进的可能性，这与该物种的配子系统有关。
Mate choice may be exercised by either sex; however, females are generally choosier than males because they invest more in their gametes. Female choice is often based on direct benefits, such as better reproductive output, whereas male choice appears to be based on differences in female fecundity. However, when gamete production is limited, sexual selection theories predict that mate choice will be decisive for reproductive success in both sexes. Here, we investigate how mating advantage is achieved in Drosophila bifurca, a giant sperm species in which both sexes produce only a few gametes. Our initial expectations were as follows: (1) females would discriminate against sperm-depleted males to avoid fertility cost; and (2) males would discriminate against inseminated females to reduce sperm competition and increase the assurance of paternity of individual gametes. Differences in courtship behaviors were analyzed with regard to the sexual maturity, which is reached after 22 days in males at 21 degrees C, and the reproductive history of both sexes (inseminated versus virgin for females, and sperm-depleted versus sperm-loaded for males). Our results show that: (1) sexual immaturity precludes mating in both sexes; (2) virgin females do not discriminate between sperm-loaded and sperm-depleted males, and (3) males mate preferentially with virgin females, because inseminated females fend off the male, which tended to bring male courtship to an end. Female remating was limited, but increased significantly when the first male was sperm-depleted. Contrary to our initial expectations, these findings suggest that male sperm depletion does not affect female mating preference, whereas the success of male courtship is driven by female behavior. The possibility that female remating was only promoted in response to low sperm transfer is discussed in relation to the gametic system of this species.