title: Two DM domain genes, DMY and DMRT1, involved in testicular differentiation and development in the medaka, Oryzias latipes.
abstract: 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.
authors.affiliation: Laboratory of Reproductive Biology, Department of Developmental Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Masaru
authors.initials: M
authors.lastname: Matsuda
authors.forename: Hiroko
authors.initials: H
authors.lastname: Kajiura-Kobayashi
authors.forename: Aya
authors.initials: A
authors.lastname: Suzuki
authors.forename: Noriko
authors.initials: N
authors.lastname: Saito
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Nakamoto
authors.forename: Naoki
authors.initials: N
authors.lastname: Shibata
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Nagahama
mesh_terms: D000818:Animals; D019070:Cell Lineage; D004268:DNA-Binding Proteins / Q000235:genetics*; D004625:Embryo, Nonmammalian; D047108:Embryonic Development; D029941:Fish Proteins / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D005854:Germ Cells / Q000378:metabolism; D057850:Hermaphroditic Organisms; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D008954:Models, Biological; D009990:Oryzias / Q000235:genetics* / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012708:Sertoli Cells / Q000378:metabolism; D019849:Sex Determination Processes; D013737:Testis / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics*; D014998:Y Chromosome
chemical_list: C110547:DMRT1 protein; D004268:DNA-Binding Proteins; D029941:Fish Proteins; D012333:RNA, Messenger; D014157:Transcription Factors