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The effects of artificial androgen (17α-methyltestoterone, MT) on the growth of Pengze curcian carp (Pcc) previtellogenic oocytes and gene expression patterns of both steroid receptor and steroidogenic genes together with Pcc-vtg B transcripts were analyzed in this study.Immature seven-month-old mono-female Pcc F2 offspring were exposed to 50, 100 μg/L of MT (week 2, 4 and 8) for three times.Some morphological indicators significantly decreased and oocyte cell development was repressed via histological check.Ovarian 11-KT decreased (P<0.01), while E2 and T increased (P<0.01), and ovarian aromatase activities also increased at week4 (P<0.01).However, in the brain tissue, these three steroid hormones and aromatase activities were highly significantly decreased.Quantitative RT-PCR analysis demonstrated that the transcripts of steroid receptor genes (Pcc-esr1, Pcc-er alpha2, Pcc-esr2a and Pcc-ar) were up-regulated, the former three of these steroidogenic genes (Pcc-3bhsd, Pcc-11bhsd2, Pcc-cyp11a1, Pcc-cyp17a1, Pcc-cyp19a1a and Pcc-star) were highly significantly increased but the latter three genes were highly significantly decreased from wee4 to week8.Ovarian and hepatopancreatic Pcc-vtg B transcripts and Vtg contents were increased in both 50 and 100 μg/L of MT exposure groups (P<0.01).The present study adds further information regarding the effects of androgens on the development of previtellogenic oocytes, which suggests MT could directly target estrogen signaling pathway, or indirectly affect steroidogenesis and vitellogenesis.