Departamento de Biología Experimental, Facultad de Ciencias Experimentales, Campus Las Lagunillas S/N, Universidad de Jaén, 23071 Jaén, Spain.
Genes (Basel). 2021 Apr 16;12(4):578. doi: 10.3390/genes12040578.
Sex is determined genetically in amphibians; however, little is known about the sex chromosomes, testis-determining genes, and the genes involved in testis differentiation in this class. Certain inherent characteristics of the species of this group, like the homomorphic sex chromosomes, the high diversity of the sex-determining mechanisms, or the existence of polyploids, may hinder the design of experiments when studying how the gonads can differentiate. Even so, other features, like their external development or the possibility of inducing sex reversal by external treatments, can be helpful. This review summarizes the current knowledge on amphibian sex determination, gonadal development, and testis differentiation. The analysis of this information, compared with the information available for other vertebrate groups, allows us to identify the evolutionarily conserved and divergent pathways involved in testis differentiation. Overall, the data confirm the previous observations in other vertebrates-the morphology of the adult testis is similar across different groups; however, the male-determining signal and the genetic networks involved in testis differentiation are not evolutionarily conserved.
性别的决定在两栖动物中是由基因决定的；然而，对于这个类群的性染色体、睾丸决定基因以及参与睾丸分化的基因知之甚少。该组物种的某些固有特征，如同质的性染色体、性别决定机制的高度多样性，或多倍体的存在，可能会在研究性腺如何分化时阻碍实验的设计。即便如此，其他特征，如外部发育或通过外部处理诱导性别反转的可能性，可能会有所帮助。这篇综述总结了目前关于两栖动物性别决定、性腺发育和睾丸分化的知识。对这些信息的分析，与其他脊椎动物组的可用信息进行比较，可以确定睾丸分化过程中涉及的进化保守和发散途径。总的来说，数据证实了其他脊椎动物的先前观察结果——不同群体的成年睾丸形态相似；然而，决定雄性的信号和参与睾丸分化的遗传网络在进化上并不保守。
