Abstract

Females usually encounter males sequentially and should discriminate between potential partners among the males that they encounter. Thus, appropriate sequential mating decisions allow females to gain mate choice benefits in the circumstance of multiple encounters. For example, if mated females can assess the genetic quality of a male prior to mating, they can remate with genetically superior males and benefit indirectly by production of offspring of superior quality (trading-up hypothesis). Additionally, because female remating generates opportunities for postcopulatory sexual selection, females can improve son quality in postcopulation processes. In the beetle Gnatocerus cornutus, females prefer mates that court vigorously before copulation and prefer attractive males, which provide indirect benefits to females because they sire attractive sons. However, there is no information about male attractiveness and the resulting fitness benefits in female remating decisions, and here we focused on this. We found that females readily remated with attractive males and that females who had mated with unattractive males readily accepted remating. Subsequently, we established four experimental treatments: a single mating with an attractive or unattractive male, mating with an attractive and then an unattractive male, and mating with an unattractive and then an attractive male. All females that mated with attractive males produced attractive sons, regardless of the order of mating with the attractive male. These results suggest that females improve son quality by trading up and biasing fertilizations toward sperm of attractive males in G. cornutus. On the other hand, no direct effect of remating on female fitness was observed.

Significance statement

When females encounter males sequentially, they must choose appropriate partners among the mates that they encounter. In the beetle Gnatocerus cornutus, proper sequential mating decisions increase the likelihood of securing sperm of attractive males when females encounter multiple mates. That is, females readily remated with attractive males, and females that mated with unattractive males readily accepted remating. Additionally, they produced attractive sons regardless of the order of the mating with attractive males. This suggests that females bias fertilizations toward the sperm of attractive males to produce attractive sons. Therefore, females may produce attractive sons by remating with attractive males and biasing fertilization toward the sperm of attractive males, indirectly increasing female fitness in G. cornutus. By contrast, remating did not affect female fitness (longevity and offspring number), and so there was no direct effect of remating on female fitness.

中文翻译：

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甲虫 Gnatocerus cornutus 的雌性交配决定和配偶选择益处

摘要

女性通常会依次遇到男性，并且应该区分他们遇到的男性中的潜在伴侣。因此，适当的顺序交配决定允许雌性在多次遭遇的情况下获得择偶利益。例如，如果交配的雌性可以在交配前评估雄性的遗传质量，它们可以与遗传上优越的雄性再交配，并通过产生优质后代而间接受益（交易假设）。此外，由于雌性交配为交配后的性选择提供了机会，因此雌性可以在交配后的过程中提高儿子的质量。在甲虫Gnatocerus cornutus，雌性更喜欢在交配前积极求爱的配偶，更喜欢有吸引力的雄性，这为雌性提供了间接的好处，因为它们生出有吸引力的儿子。然而，没有关于男性吸引力和女性重新择偶决定中由此产生的健康益处的信息，我们在这里关注这一点。我们发现雌性很容易与有魅力的雄性交配，而与没有吸引力的雄性交配的雌性很容易接受再交配。随后，我们建立了四种实验处理方法：与有吸引力或不吸引人的雄性单次交配，与有吸引力然后再不吸引人的雄性交配，以及与不吸引人然后再有吸引力的雄性交配。无论与有魅力的雄性交配的顺序如何，所有与有魅力的雄性交配的雌性都会产生有魅力的儿子。G.cornutus。另一方面，没有观察到交配对女性健康的直接影响。

意义陈述

当雌性依次遇到雄性时，它们必须在遇到的配偶中选择合适的伴侣。在Gnatocerus cornutus甲虫中，当雌性遇到多个配偶时，适当的顺序交配决定增加了获得有吸引力的雄性精子的可能性。也就是说，雌性很容易与有吸引力的雄性交配，而与没有吸引力的雄性交配的雌性很容易接受再交配。此外，无论与有吸引力的雄性交配的顺序如何，它们都产生了有吸引力的儿子。这表明雌性将受精偏向有吸引力的雄性的精子以产生有吸引力的儿子。因此，雌性可能会通过与有魅力的雄性重新交配，并将受精偏向有魅力的雄性的精子，从而产生有魅力的儿子，从而间接提高女性的适应性。G.cornutus。相比之下，重新交配不影响女性健康（寿命和后代数量），因此重新交配对女性健康没有直接影响。