The effects of different MT treatment methods on the ovarian transcriptome of Pampus argenteus.

17α-methyltestosterone (MT) is a synthetic androgen that is commonly used to induce sex reversal in teleost fish. In this study, MT treatment of Pampus argenteus was carried out by different methods to find the best treatment method and potential mechanism. The results showed that compared with the control group, low concentration of MT (50 mg/kg) could improve the growth performance of P. argenteus in 30 days. Gonadal histology showed that different treatments of MT had different inhibition on the ovarian development, and the number of oocytes decreased in the ovaries. The ovaries of the immersing treatment groups (10 μg/l) showed ovotestis state, but the male germ cells were in the spermatogonia stage. The E2 levels of the mixed feeding and immersing treatment groups was significantly higher than that of the control group (P < 0.05). The 11-KT levels in the 100 mg/kg group was significantly higher than that in the control group (P < 0.05). For the gonadal transcriptome analysis after MT treatment, 460, 568 and 381 DEGs were screened in the 50MT group, 100MT group and MT immersing group, respectively. The DEGs in 50 MT group were enriched in calcium signaling pathway and MAPK signaling pathway affecting gonadal development and differentiation. In 100 MT group, DEGs were mainly enriched in neuroactive ligand-receptor interaction, purine metabolism, vascular smooth muscle contraction and other pathways. The differential gene enrichment p53 signaling pathway and PPAR signaling pathway in the immersing group had an effect on the gonads. In this study, genes showing significant changes in expression after MT treatment were identified. The possible regulatory mechanism of 17α-methyltestosterone on gonadal development of Pampus argenteus was speculated. It provides a theoretical basis for exploring effective ways to improve the fertilization rate of P. argenteus.