A general theory of sexual differentiation.
A general theory of sexual differentiation.
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DOI：
10.1002/jnr.23884
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发表时间：
2017-01-02
影响因子：
4.2
通讯作者：
Arnold AP
中科院分区：
文献类型：
--
作者：
Arnold AP
提出了哺乳动物性别分化的一般理论。所有的生物性别差异都是性染色体作用不平等的结果，性染色体是XX受精卵与XY受精卵唯一不同的因素。这种不平等导致了男性特有的Y染色体效应，包括导致睾丸分化的睾丸决定基因Sry的表达。因此，Sry在性腺激素的影响上建立了终生的性别差异。Y基因也作用于性腺外，导致男性特有的影响。XX和XY细胞之间X染色体数目的差异导致了(1)Xist、(2)逃脱失活的X基因和(2)父母印记的X基因表达的性别差异。表型上的性别差异最终是多种独立的性别偏见因素、荷尔蒙和性染色体的结果。这些因素并行并结合在一起，导致了性别差异。它们还可以相互抵消，以减少性别差异。在人口层面运作的其他机制导致男性群体平均不同于女性群体。该理论具有优势，可以引导人们注意内在的性别偏见因素，这些因素在许多组织中发挥作用，导致性别差异，导致对疾病的性别偏见保护，并为进一步研究构建问题框架。
A general theory of mammalian sexual differentiation is proposed. All biological sex differences are the result of the inequality in effects of the sex chromosomes, which are the only factors that differ in XX vs. XY zygotes. This inequality leads to male-specific effects of the Y chromosome, including expression of the testis-determining gene Sry that causes differentiation of testes. Thus, Sry sets up lifelong sex differences in effects of gonadal hormones. Y genes also act outside of the gonads to cause male-specific effects. Differences in the number of X chromosomes between XX and XY cells causes sex differences in expression (1) of Xist, (2) of X genes that escape inactivation, and (2) of parentally imprinted X genes. Sex differences in phenotype are ultimately the result of multiple, independent sex-biasing factors, hormonal and sex chromosomal. These factors act in parallel and in combination to induce sex differences. They can also can offset each other to reduce sex differences. Other mechanisms, operating at the level of populations, cause groups of males to differ on average from groups of females. The theory has advantages for directing attention to inherent sex-biasing factors that operate in many tissues to cause sex differences, to cause sex-biased protection from disease, and to frame questions for further study.