Male polymorphism inLimia perugiae (Pisces: Poeciliidae)
Male polymorphism inLimia perugiae (Pisces: Poeciliidae)
复制标题
Limia perugiae 的雄性多态性（双鱼座：Poeciliidae）
作者：
Claudia Erbelding;J. Schröder;M. Schartl;I. Nanda;M. Schmid;J. Epplen
雄性多态性鱼类 Limia perugiae 是加勒比海岛伊斯帕尼奥拉岛东南部特有的一种小型硬骨鱼，由三种雄性体型和均匀的雌性组成。大型雄性的区别在于尺寸在 25 至 38 毫米之间；中等雄性，21至25毫米之间。在竞争中，体型较大的雄性会表现出复杂的求爱行为，而体型较小的雄性则只会表现出偷偷追逐的行为。中级雄性会根据各自的竞争对手调整策略。然而，所有雄性变体都可以从求爱行为转变为偷偷追逐行为。在由四只不同体型的雄性和五六只未交配的雌性组成的大型交配群体中，较大的占主导地位的α-雄性和较小的从属δ-雄性不会产生任何后代。出乎意料的是，所有后代都是由中间从属的β-和γ-雄性产生的。三种雄性变体的育种实验可以通过小体型和大体型的 Y 连锁基因模型来最好地解释，这些基因都因负责中间雄性发育的常染色体隐性抑制子的活性而暂停。隐性阻遏蛋白的显性等位基因，无论处于同源杂合状态，都会分别激活大或小尺寸的Y染色体基因。因此，中间雄性可以产生各种体型的雄性后代，这取决于 Y 连锁基因或常染色体阻遏物的存在。
The male-polymorphic poeciliid fish,Limia perugiae, a small teleostean endemic to the southeast of the Caribbean island Hispañola, consists of three male size morphs with uniform females. Large males differentiate at a size varying between 25 and 38 mm; intermediate males, between 21 and 25 mm. Under competition, large males exhibit an elaborate courship display, whereas small males show only a sneak-chase behavior. Intermediate males adapt their tactics to the respective competitors. However, all male morphs can switch from courtship display to sneak-chase behavior. In large mating groups with four males of different size and five or six virgin females, large dominant α-males as well as small subordinate δ-males did not produce any offspring. Unexpectedly, all progeny were sired exclusively by the intemediate subordinate β- and γ-males. Breeding experiments with the three male morphs can best be explained by a model of Y-linked genes for small and large size which are both suspended by the activity of an autosomal recessive repressor responsible for the development of intermediate males. The dominant allele of the recessive repressor, in either its homoorits heteozygous state, activates the Y-chromosomal genes for large or small size, respectively. Accordingly, intermediate males may produce male offspring of all size classes, depending on the presence of either the Y-linked gene or the autosomal repressor.