Sex-specific gonadal transcriptome during early development of Siberian sturgeon

By 2.5 months of age, sex-specific gonadal differences are already apparent in Siberian sturgeon. This study highlights the estrogen response pathway, including immediate early response genes described here for the first time in the context of fish gonadal differentiation. At the same time, an estrogen-independent ovarian pathway cannot be ruled out. Male differentiation appears to involve tbx1 together with new candidates for testis regulation in the absence of sex-biased androgen-producing enzymes. These novel genes expressed near the onset of sex differentiation merit further investigation.