Department Integrative Biology and Physiology, University of California, Los Angeles, United States of America.
Horm Behav. 2020 Apr;120:104691. doi: 10.1016/j.yhbeh.2020.104691. Epub 2020 Jan 31.
This paper is part of the celebration of the 50th anniversary of founding of the journal Hormones and Behavior, the official journal of the Society for Behavioral Neuroendocrinology. All sex differences in phenotypic development stem from the sexual imbalance in X and Y chromosomes, which are the only known differences in XX and XY zygotes. The sex chromosome genes act within cells to cause differences in phenotypes of XX and XY cells throughout the body. In the gonad, they determine the type of gonad, leading to differences in secretion of testicular vs. ovarian hormones, which cause further sex differences in tissue function. These current ideas of sexual differentiation are briefly contrasted with a hormones-only view of sexual differentiation of the last century. The multiple, independent action of diverse sex-biasing agents means that sex-biased factors can be synergistic, increasing sex differences, or compensatory, making the two sexes more equal. Several animal models have been fruitful in demonstrating sex chromosome effects, and interactions with gonadal hormones. MRI studies of human brains demonstrate variation in brain structure associated with both differences in gonadal hormones, and in the number of X and Y chromosomes. Five unanswered questions are posed as a challenge to future investigators to improve understanding of sexual differentiation throughout the body.
本文是为庆祝《激素与行为杂志》（神经行为内分泌学会官方期刊）创刊 50 周年而撰写的。所有表型发育的性别差异都源于 X 和 Y 染色体的性不平衡，这是 XX 和 XY 受精卵中唯一已知的差异。性染色体基因在细胞内发挥作用，导致 XX 和 XY 细胞在整个身体中的表型差异。在性腺中，它们决定性腺的类型，导致睾丸激素与卵巢激素分泌的差异，从而进一步导致组织功能的性别差异。这些关于性分化的当前观点与上世纪仅关注激素的性分化观点进行了简要对比。多种、独立的性别偏向因素作用意味着性别偏向因素可以协同作用，增加性别差异，或者相互补偿，使两性更加平等。一些动物模型在证明性染色体的作用以及与性腺激素的相互作用方面取得了丰硕成果。对人类大脑的 MRI 研究表明，与性腺激素差异以及 X 和 Y 染色体数量相关的大脑结构存在差异。提出了五个未解决的问题，作为对未来研究人员的挑战，以提高对全身性分化的理解。
