Abstract

Sexual dimorphism is a device that supports genetic diversity while providing selective pressure against speciation. This phenomenon is at the core of sexually reproducing organisms. Caenorhabditis elegans provides a unique experimental system where males exist in a primarily hermaphroditic species. Early works of John Sulston, Robert Horvitz, and John White provided a complete map of the hermaphrodite nervous system, and recently the male nervous system was added. This addition completely realized the vision of C. elegans pioneer Sydney Brenner: a model organism with an entirely mapped nervous system. With this ‘connectome’ of information available, great strides have been made toward understanding concepts such as how a sex-shared nervous system (in hermaphrodites and males) can give rise to sex-specific functions, how neural plasticity plays a role in developing a dimorphic nervous system, and how a shared nervous system receives and processes external cues in a sexually-dimorphic manner to generate sex-specific behaviors. In C. elegans, the intricacies of male-mating behavior have been crucial for studying the function and circuitry of the male-specific nervous system and used as a model for studying human autosomal dominant polycystic kidney disease (ADPKD). With the emergence of CRISPR, a seemingly limitless tool for generating genomic mutations with pinpoint precision, the C. elegans model system will continue to be a useful instrument for pioneering research in the fields of behavior, reproductive biology, and neurogenetics.

摘要

性别二态性是一种支持遗传多样性，同时提供针对物种形成的选择性压力的装置。这种现象是有性生殖生物的核心。秀丽隐杆线虫提供了一个独特的实验系统，其中雄性主要存在于雌雄同体的物种中。约翰·苏尔斯顿、罗伯特·霍维茨和约翰·怀特的早期作品提供了雌雄同体神经系统的完整地图，最近又添加了男性神经系统。这一添加完全实现了线虫先驱悉尼·布伦纳 (Sydney Brenner)的愿景：一种具有完全映射的神经系统的模型生物。有了这些可用的“连接组”信息，我们在理解诸如性别共享神经系统（雌雄同体和男性）如何产生性别特异性功能、神经可塑性如何在发育中发挥作用等概念方面取得了巨大进步。二态性神经系统，以及共享神经系统如何以性别二态性方式接收和处理外部线索以产生性别特异性行为。在秀丽隐杆线虫中，复杂的雄性交配行为对于研究雄性特有的神经系统的功能和回路至关重要，并被用作研究人类常染色体显性多囊肾病（ADPKD）的模型。随着 CRISPR 这种看似无限的工具的出现，它可以精确地产生基因组突变，线虫模型系统将继续成为行为、生殖生物学和神经遗传学领域开创性研究的有用工具。