A diverse array of sex determination (SD) mechanisms, encompassing environmental to genetic, have been found to exist among vertebrates, covering a spectrum from fixed SD mechanisms (mammals) to functional sex change in fishes (sequential hermaphroditic fishes). A major landmark in vertebrate SD was the discovery of the SRY gene in 1990. Since that time, many attempts to clone an SRY ortholog from non-mammalian vertebrates remained unsuccessful, until 2002, when DMY/DMRT1BY was discovered as the SD gene of a small fish, medaka. Surprisingly, however, DMY/DMRT1BYwas found in only two species among more than 20 species of medaka, suggesting a large diversity of SD genes among vertebrates. Considerable progress has been made over the last 3 decades, such that it is now possible to formulate reasonable paradigms of how SD and gonadal sex differentiation may work in some model vertebrate species. This review outlines our current understanding of vertebrate SD and gonadal sex differentiation, with a focus on the molecular and cellular mechanisms involved. An impressive number of genes and factors have been discovered that play important roles in testicular and ovarian differentiation. An antagonism between the male and female pathway genes exists in gonads during both sex differentiation and, surprisingly, even as adults, suggesting that, in addition to sex-changing fishes, gonochoristic vertebrates including mice maintain some degree of gonadal sexual plasticity into adulthood. Importantly, reviewing various SD mechanisms among vertebrates suggest that this is the ideal biological event that can make us understand the evolutionary conundrums underlying speciation and species diversity.

中文翻译：

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脊椎动物的性别决定、性腺性别分化和可塑性

已经发现脊椎动物中存在多种性别决定 (SD) 机制，包括环境到遗传，涵盖从固定的 SD 机制（哺乳动物）到鱼类（顺序雌雄同体鱼类）的功能性性别变化。脊椎动物 SD 的一个主要里程碑是 1990 年 SRY 基因的发现。从那时起，许多从非哺乳动物脊椎动物中克隆 SRY 直向同源物的尝试仍未成功，直到 2002 年，DMY/DMRT1BY 被发现作为小鱼，青鳉。然而，令人惊讶的是，DMY/DMRT1BY 在 20 多种青鳉中仅发现两种，表明脊椎动物中 SD 基因存在很大差异。在过去的 3 年里取得了相当大的进步，这样现在就可以制定合理的范式，说明 SD 和性腺性别分化如何在某些模型脊椎动物物种中起作用。这篇综述概述了我们目前对脊椎动物 SD 和性腺性别分化的理解，重点是所涉及的分子和细胞机制。已发现大量基因和因子在睾丸和卵巢分化中起重要作用。雄性和雌性通路基因在性别分化过程中存在于性腺中，令人惊讶的是，即使在成年期也存在拮抗作用，这表明除了改变性别的鱼类外，包括小鼠在内的生殖道脊椎动物在成年期仍保持一定程度的性腺性可塑性。重要的，