Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, USA.
Bioessays. 2013 Aug;35(8):725-32. doi: 10.1002/bies.201300009. Epub 2013 Jun 26.
The differentiation of male and female characteristics in vertebrates and insects has long been thought to proceed via different mechanisms. Traditionally, vertebrate sexual development was thought to occur in two phases: a primary and a secondary phase, the primary phase involving the differentiation of the gonads, and the secondary phase involving the differentiation of other sexual traits via the influence of sex hormones secreted by the gonads. In contrast, insect sexual development was thought to depend exclusively on cell-autonomous expression of sex-specific genes. Recently, however, new evidence indicates that both vertebrates and insects rely on sex hormones as well as cell-autonomous mechanisms to develop sexual traits. Collectively, these new data challenge the traditional vertebrate definitions of primary and secondary sexual development, call for a redefinition of these terms, and indicate the need for research aimed at explaining the relative dependence on cell-autonomous versus hormonally guided sexual development in animals.
长期以来，人们一直认为脊椎动物和昆虫的雌雄特征分化是通过不同的机制进行的。传统上，脊椎动物的性发育被认为经历两个阶段：一个是初级阶段，一个是次级阶段，初级阶段涉及性腺的分化，次级阶段则通过性腺分泌的性激素对其他性特征的分化产生影响。相比之下，昆虫的性发育被认为完全依赖于性特异性基因的细胞自主表达。然而，最近的新证据表明，脊椎动物和昆虫都依赖于性激素以及细胞自主机制来发育性特征。总的来说，这些新数据挑战了传统的脊椎动物对初级和次级性发育的定义，呼吁重新定义这些术语，并表明需要研究旨在解释动物中对细胞自主与激素指导的性发育的相对依赖。
