A Duplicated, Truncated amh Gene Is Involved in Male Sex Determination in an Old World Silverside

作者:Bej Dilip Kumar; Miyoshi Kaho; Hattori Ricardo S; Strussmann Carlos A; Yamamoto Yoji*
来源:Genes Genomes Genetics, 2017, 7(8): 2489-2495.
DOI:10.1534/g3.117.042697

摘要

A master sex-determining gene, the Y chromosome-linked anti-Mulerian hormone (amhy) gene, has been described in two New World atheriniform species but little is known on the distribution, evolution, and s) of this gene in other Atheriniformes. Interestingly, amhy has been found to coexist with temperature-dependent sex determination (TSD), providing a unique opportunity to explore the interplay between genotypic and environmental sex determination. In this study, the search for an amhy homolog was extended to an Old World atheriniform, the cobaltcap silverside Hypoatherina tsurugae (Atherinidae). The full sequences, including the coding and noncoding regions, of the autosomal amh (amha) and a putative amhy were obtained. The deduced Amha and Amhy proteins comprised 511 and 340 amino acids (aa), respectively. PCR analysis with genomic DNA from wild adults and from laboratoryreared juveniles revealed a high, but not complete association of similar to 95% between amhy and maleness. The spatiotemporal expression of amhy and amha during gonadal sex differentiation was analyzed by qRT-PCR and in situ hybridization (ISH). amhy transcription (in amhy-positive larvae) started before and peaked during histological differentiation of the gonads whereas amha was negligible during the same period in both genotypes. These results demonstrate that the amhy, although with some structural differences in relation to the amhy of some New World atheriniforms, is strongly associated with maleness and probably important for testicular development in this Old World atheriniform. Thus, amhy is a candidate sex determination gene in cobaltcap silverside and it will be key to scrutinize the mechanism of sex determination in this species.

  • 出版日期2017-8