A Y-linked anti-Müllerian hormone duplication takes over a critical role in sex determination.
Gonadal sex determination in vertebrates generally follows a sequence of genetically programmed events. In what is seemingly becoming a pattern, all confirmed or current candidate "master" sex-determining genes reported in this group, e.g., SRY in eutherian mammals, DMY/dmrt1bY in medaka, DM-W in the African clawed frog, and DMRT1 in chicken encode transcription factors. In contrast, here we show that a male-specific, duplicated copy of the anti-Müllerian hormone (amh) is implicated in testicular development of the teleost fish Patagonian pejerrey (Odontesthes hatcheri). The gene, termed amhy because it is found in a single metacentric/submetacentric chromosome of XY individuals, is expressed much earlier than the autosomal amh (6 d after fertilization vs. 12 wk after fertilization) and is localized to presumptive Sertoli cells of XY males during testicular differentiation. Moreover, amhy knockdown in XY embryos resulted in the up-regulation of foxl2 and cyp19a1a mRNAs and the development of ovaries. These results are evidence of a functional amh duplication in vertebrates and suggest that amhy may be the master sex-determining gene in this species. If confirmed, this would be a unique instance of a hormone-related gene, a member of the TGF-β superfamily, in such a role.
Graduate School of Marine Science and Technology,  Tokyo University of Marine Science and Technology, Tokyo 108-8477,  Japan.
Ricardo S
RS
Hattori
Yu
Y
Murai
Miho
M
Oura
Shuji
S
Masuda
Sullip K
SK
Majhi
Takashi
T
Sakamoto
Juan I
JI
Fernandino
Gustavo M
GM
Somoza
Masashi
M
Yokota
Carlos A
CA
Strüssmann
D000818:Animals; D054304:Anti-Mullerian Hormone / Q000235:genetics*; D047108:Embryonic Development / Q000187:drug effects / Q000235:genetics; D005260:Female; D005399:Fishes / Q000235:genetics* / Q000254:growth & development; D020440:Gene Duplication / Q000187:drug effects / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D055785:Gene Knockdown Techniques; D005819:Genetic Markers; D008297:Male; D060172:Morpholinos / Q000494:pharmacology; D010053:Ovary / Q000187:drug effects / Q000254:growth & development; D020161:Physical Chromosome Mapping; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D019849:Sex Determination Processes / Q000187:drug effects / Q000235:genetics*; D013737:Testis / Q000187:drug effects / Q000254:growth & development; D013997:Time Factors; D014998:Y Chromosome / Q000235:genetics*
D005819:Genetic Markers; D060172:Morpholinos; D012333:RNA, Messenger; D054304:Anti-Mullerian Hormone