Postcopulatory, prezygotic isolation: intraspecific and interspecific sperm precedence in Tribolium spp., flour beetles.
Postcopulatory, prezygotic isolation: intraspecific and interspecific sperm precedence in Tribolium spp., flour beetles.
复制标题
交配后、合子前隔离：谷盗属、面粉甲虫的种内和种间精子优先权。
作者：
Robinson,T;Johnson,NA;Wade,MJ
本文研究了粉甲虫（Tribolium castaneum）种内和种间的父权模式，方法是将雌性与同种雄虫配对，或与近缘种Tribolium freemani的一个同种和一个异种雄虫配对。这两个物种的雌性在交配后和交配后都将精子储存在精子囊中，这对物种之间存在着合子前生殖隔离的报道。当具有对比基因型的同种雄性与雌性同时交配时，我们观察到雌性在精子优先模式上的高度差异，正如后代基因型所显示的那样。与此相反，castaneum雌虫与同种雄虫和异种雄虫同时交配产生超过99%的同种后代。在3 ~ 7天内，同种雄虫与雌虫依次交配，后代均由第二雄虫承继。相比之下，当同一种雄虫被同一种雄虫取代时，大多数雌虫在接下来的10天里继续只生产第一种雄虫，同一种的后代。当异种雄代替换为同种雄代时，雌代在3天内从产生杂种转变为产生同种后代。我们讨论了这些发现的进化意义。
We investigated intraspecific and interspecific patterns of paternity in Tribolium castaneum, the flour beetle, by mating females either to pairs of conspecific males or to one conspecific and one heterospecific male of the closely related species, T. freemani. Females of both species store sperm in the spermatheca after copulation and postcopulatory, prezygotic reproductive isolation has been reported between this pair of species. When conspecific males of contrasting genotype were mated simultaneously to T. castaneum females, we observed extremely high levels of variation among females in the pattern of sperm precedence as shown by the offspring genotypes. In contrast, T. castaneum females mated simultaneously to a conspecific and a heterospecific male produced over 99 per cent conspecific progeny. When conspecific males were mated sequentially to T. castaneum females, within 3-7 days, all offspring were sired by the second male. In contrast, when a conspecific male was replaced with a T. freemani male, most females continued to produce only first-male, conspecific offspring for the next 10 days. When a heterospecific male was replaced with a conspecific male, T. castaneum females changed from producing hybrid to conspecific offspring within 3 days. We discuss the evolutionary implications of these findings.