Delbridge M L, Graves J A
Department of Biochemistry and Genetics, La Trobe University, Bundoora, Victoria, Australia.
Rev Reprod. 1999 May;4(2):101-9. doi: 10.1530/ror.0.0040101.
All mammals have an XY chromosomal sex determining system, in which a small Y chromosome triggers male development, and contains genes required for spermatogenesis. The X and Y chromosomes were originally homologous, but diverged during evolution as the Y chromosome was degraded progressively. Comparisons among the sex chromosomes of different mammal groups indicate that the X and Y chromosomes received additions of material from other chromosomes. Genes on the Y chromosome originated from the ancient X-Y pair, or from these additions, or were copies of genes on one of the autosomes. Only genes with important male-specific functions, such as sex determination and spermatogenesis, are selected for and retained on the differential region of the Y chromosome. The mammalian sex determining gene, SRY, controls the testis determination pathway, which includes at least one related gene. Several candidate spermatogenesis genes have been identified, but so far the only one that is conserved on the Y chromosome of all therian mammals is RBM (RNA-binding motif gene, Y chromosome).
所有哺乳动物都有XY染色体性别决定系统，其中小的Y染色体触发雄性发育，并包含精子发生所需的基因。X和Y染色体最初是同源的，但在进化过程中随着Y染色体逐渐退化而发生了分化。不同哺乳动物群体性染色体之间的比较表明，X和Y染色体从其他染色体获得了物质添加。Y染色体上的基因起源于古老的X-Y对，或源于这些添加物，或为常染色体之一上基因的拷贝。只有具有重要雄性特异性功能的基因，如性别决定和精子发生相关基因，才会被选择并保留在Y染色体的差异区域。哺乳动物的性别决定基因SRY控制睾丸决定途径，该途径至少包括一个相关基因。已经鉴定出几个候选精子发生基因，但到目前为止，在所有兽亚纲哺乳动物的Y染色体上保守的唯一基因是RBM（RNA结合基序基因，Y染色体）。
