Department of Anatomy, University of Otago, Dunedin, New Zealand.
Department of Anatomy, University of Otago, Dunedin, New Zealand.
Curr Top Dev Biol. 2019;134:71-117. doi: 10.1016/bs.ctdb.2018.12.014. Epub 2019 Jan 30.
Sexual fate can no longer be considered an irreversible deterministic process that once established during early embryonic development, plays out unchanged across an organism's life. Rather, it appears to be a dynamic process, with sexual phenotype determined through an ongoing battle for supremacy between antagonistic male and female developmental pathways. That sexual fate is not final and is actively regulated via the suppression or activation of opposing genetic networks creates the potential for flexibility in sexual phenotype in adulthood. Such flexibility is seen in many fish, where sex change is a usual and adaptive part of the life cycle. Many fish are sequential hermaphrodites, beginning life as one sex and changing sometime later to the other. Sequential hermaphrodites include species capable of female-to-male (protogynous), male-to-female (protandrous), or bidirectional (serial) sex change. These natural forms of sex change involve coordinated transformations across multiple biological systems, including behavioral, anatomical, neuroendocrine and molecular axes. Here we review the biological processes underlying this amazing transformation, focusing particularly on the molecular aspects, where new genomic technologies are beginning to help us understand how sex change is initiated and regulated at the molecular level.
性命运不再被认为是一个在早期胚胎发育过程中一旦确定就不变地贯穿生物体一生的不可逆的确定性过程。相反，它似乎是一个动态的过程，性表型是通过拮抗的雄性和雌性发育途径之间的持续竞争来决定的。性命运不是最终的，并且通过抑制或激活相反的遗传网络来积极调节，这为成年后的性表型的灵活性创造了潜力。这种灵活性在许多鱼类中可见，其中性别转换是生命周期中常见的适应性部分。许多鱼类是顺序雌雄同体，一生开始时为一种性别，后来再变为另一种性别。顺序雌雄同体包括能够进行雌性到雄性（雌转雄）、雄性到雌性（雄转雌）或双向（序列）性别转换的物种。这些自然形式的性别转换涉及多个生物系统的协调转化，包括行为、解剖、神经内分泌和分子轴。在这里，我们回顾了这种惊人转化的生物学过程，特别关注分子方面，新的基因组技术开始帮助我们了解性别转换如何在分子水平上启动和调节。
