Kobayashi Tohru, Matsuda Masaru, Kajiura-Kobayashi Hiroko, Suzuki Aya, Saito Noriko, Nakamoto Masatoshi, Shibata Naoki, Nagahama Yoshitaka
Laboratory of Reproductive Biology, Department of Developmental Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan.
Dev Dyn. 2004 Nov;231(3):518-26. doi: 10.1002/dvdy.20158.
The recent discovery of the DMY gene (DM domain gene on Y chromosome and one of the DMRT1 family genes) as a key determinant of male development in the medaka (Oryzias latipes) has led to its designation as the prime candidate gene for sex-determination in this species. This study focused on the sites and pattern of expression of DMY and DMRT1 genes during gonadal differentiation of medaka to further determine their roles in testis development. DMY mRNA and protein are expressed specifically in the somatic cells surrounding primordial germ cells (PGCs) in the early gonadal primordium, before morphological sex differences are seen. However, somatic cells surrounding PGCs never express DMY during the early migratory period. Expression of DMY persists in Sertoli cell lineage cells, from PGC-supporting cells to Sertoli cells, indicating that only DMY-positive cells enclose PGCs during mitotic arrest after hatching. DMRT1 is expressed in spermatogonium-supporting cells after testicular differentiation (20-30 days after hatching), and its expression is much higher than that of DMY in mature testes. In XX sex-reversed testes, DMRT1 is expressed in the Sertoli cell lineage, similar to the expression of DMY in XY testes. These results suggest strongly that DMY regulates PGC proliferation and differentiation sex-specifically during early gonadal differentiation of XY individuals and that DMRT1 regulates spermatogonial differentiation.
最近发现的DMY基因（Y染色体上的DM结构域基因，也是DMRT1家族基因之一）是青鳉（Oryzias latipes）雄性发育的关键决定因素，这使其被指定为该物种性别决定的主要候选基因。本研究聚焦于青鳉性腺分化过程中DMY和DMRT1基因的表达位点及模式，以进一步确定它们在睾丸发育中的作用。在形态学性别差异出现之前，DMY mRNA和蛋白在性腺原基早期原始生殖细胞（PGC）周围的体细胞中特异性表达。然而，在早期迁移阶段，PGC周围的体细胞从不表达DMY。DMY在从PGC支持细胞到支持细胞的支持细胞谱系细胞中持续表达，这表明在孵化后的有丝分裂停滞期间，只有DMY阳性细胞包围PGC。DMRT1在睾丸分化后（孵化后20 - 30天）在精原细胞支持细胞中表达，并且在成熟睾丸中其表达远高于DMY。在XX性反转睾丸中，DMRT1在支持细胞谱系中表达，类似于XY睾丸中DMY的表达。这些结果有力地表明，DMY在XY个体性腺早期分化过程中特异性地调节PGC的增殖和分化，而DMRT1调节精原细胞的分化。
