Understanding how sex differences in innate animal behaviors arise has long fascinated biologists. As a general rule, the potential for sex differences in behavior is built by the developmental actions of sex-specific hormones or regulatory proteins that direct the sexual differentiation of the nervous system. In the last decade, studies in several animal systems have uncovered neural circuit mechanisms underlying discrete sexually dimorphic behaviors. Moreover, how certain hormones and regulatory proteins implement the sexual differentiation of these neural circuits has been illuminated in tremendous detail. Here, we discuss some of these mechanisms with three case-studies—mate recognition in flies, maturation of mating behavior in worms, and play-fighting behavior in young rodents. These studies illustrate general and unique developmental mechanisms to establish sex differences in neuroanatomy and behavior and highlight future challenges for the field.

早就使生物学家着迷的是了解先天动物行为中的性别差异是如何产生的。作为一般规则，行为上性别差异的可能性是由指导神经系统性别分化的性别特异性激素或调节蛋白的发育作用建立的。在过去的十年中，对几种动物系统的研究发现了离散的性二态性行为背后的神经回路机制。此外，已经非常详细地阐明了某些激素和调节蛋白如何实现这些神经回路的性别分化。在这里，我们通过三个案例研究来讨论其中的一些机制：果蝇中的配偶识别，蠕虫中交配行为的成熟以及年轻啮齿动物的打架行为。