Proximal traits and mechanisms for biasing paternity in the red flour beetle Tribolium castaneum (Coleoptera: Tenebrionidae)
Proximal traits and mechanisms for biasing paternity in the red flour beetle Tribolium castaneum (Coleoptera: Tenebrionidae)
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DOI：
10.1007/s00265-006-0228-7
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发表时间：
2006-10-01
影响因子：
2.3
通讯作者：
Lewis, Sara M.
中科院分区：
文献类型：
--
作者：
Fedina, Tatyana Yu;Lewis, Sara M.
对性选择的全面理解需要了解与与同一只雌性交配的其他雄性相比，增加雄性亲子关系份额(后代比例)的特征和机制。在这项研究中，我们通过饥饿来操纵可能影响雄性亲权份额的性状在卡氏拟谷盗中的表达。然后，我们进行了实验，以考察在从交配到后代生产的一连串的性选择过程中，雄性饥饿如何影响雄性的表现，并通过使用活的和死的雌性来研究雌性在特定阶段的控制。饥饿雄性与喂食雄性的比较表明，雌性在交配过程中控制着精子团的转移，因为活着的雌性拒绝饥饿(“低质量”)雄性的受精。测量的男性交配行为(腿部摩擦频率、不对称性和摩擦时间百分比)都不影响授精成功的可能性，但后两种行为与男性父亲份额呈正相关。雄性处理(饥饿/喂养)、雌性处理(活/死)或雄性交配行为不影响雌性生殖道内的精原细胞定位。然而，饥饿对男性生殖生理有很大的影响，减少了附腺的大小和转移的精子总数(但不包括精子在精囊中的存活率)。此外，与饥饿雄性交配的雌性在其受精囊中储存的精子较少，再加上射精大小的减少，这可能解释了与喂食雄性相比，饥饿雄性的父子份额减少的原因。这项研究阐明了一些影响男性生殖成功的隐秘机制，并有助于我们通过性别选择来理解性状进化。
A comprehensive understanding of sexual selection requires knowledge of the traits and mechanisms responsible for increasing a male's paternity share (proportion of progeny sired) relative to that of other males mating with the same female. In this study we manipulated by starvation the expression of traits that might influence male paternity share in Tribolium castaneum. We then conducted experiments to examine how male starvation affects male performance during sequential episodes of sexual selection from mating to progeny production, and investigated female control over specific stages by using live vs dead females. Comparison of starved vs fed males revealed that T. castaneum females have control over spermatophore transfer during mating, as live females rejected inseminations by starved ("low quality") males. None of the measured male copulatory behaviors (leg-rubbing frequency, asymmetry, and percent of time spent rubbing) affected the probability of successful insemination, but the last two were positively associated with male paternity share. Spermatophore positioning within the female reproductive tract was not affected by male treatment (starved/fed), by female treatment (live/dead), or by male copulatory behaviors. Starvation, however, had a dramatic effect on male reproductive physiology, decreasing both accessory gland size and total number of sperms transferred (but not sperm viability in seminal vesicles). In addition, females who mated to starved males stored fewer sperms in their spermathecae, which, together with decreased ejaculate size, may explain the reduced paternity share of starved males compared to fed males. This study elucidates some cryptic mechanisms influencing male reproductive success and aids our understanding of trait evolution through sexual selection.