Characterization and sequencing of the sex determining region Y gene (Sty) in Akodon (Cricetidae) species with sex reversed females

BIANCHI NO; BIANCHI MS; BAILLIET G; DE LA CHAPELLE A

CHROMOSOMA

SPRINGER

Lugar: Berlin; Año: 1993 vol. 102 p. 389 - 395

0009-5915

The sex determining region Y gene (Sry) is the strongest candidate to be the testis determining factor gene (Tdy). Several South-American Akodon species havetwo varieties of Y chromosome. One type transmitted via male specimens induces testis development. The second Y variety fails to induce male gonadal differentiation and gives rise to fully fertile XY females. These variant females test positive for Sry. Moreover, sequencing of a partial open reading frame of the conserved region of Sry from males and XY females shows no sequence difference. Sty is two- to sixfold amplified in six of eight akodont species tested. Since Sry amplification was found in species having and not having XY females, amplification apparently does not in itself play a primary role in the origin of sex reversal. The development of fully fertile ovaries in XY Akodon females is not due to a deletion of Sty or to mutations in the Sty segment analyzed in this report. Sex reversal may be due to abnormal expressionof this gene at the stage of gonadal differentiation. Alternatively, other genes in the sex-determining pathway may be involved. Several of the Akodon speciesshowing Sty amplification also have amplification of Zfy, which may map to the same region of the Akodon Y chromosome.