Department of Zoology, Taki Government College, Taki, India.
Endocrinology Laboratory, Department of Zoology, University of Kalyani, Kalyani, India.
J Exp Zool A Ecol Integr Physiol. 2018 Jan;329(1):29-42. doi: 10.1002/jez.2158. Epub 2018 Apr 18.
Cytochrome P450arom (CYP19), a product of cyp19a1 gene, catalyzes the conversion of androgens to estrogens and is essential for regulation of reproductive function in vertebrates. In the present study, we isolated partial cDNA encoding the ovarian (cyp19a1a) and brain (cyp19a1b) P450arom genes from adult female perch, Anabas testudineus and investigated their regulation by estrogen in vivo. Results demonstrated that cyp19a1a and cyp19a1b predominate in ovary and brain respectively, with quantity of both attuned to reproductive cycle. To elucidate estrogen-regulated expression of cyp19a1b in brain and cyp19a1a in ovary, dose- and time-dependent studies were conducted with estrogen in vitellogenic-stage fish in the presence or absence of specific aromatase inhibitor fadrozole. Results demonstrated that treatment of fish with 17β-estradiol (E2; 1.0 μM)) for 6 days caused significant upregulation of cyp19a1b transcripts, aromatase B protein, and aromatase activity in brain in a dose- and time-dependent manner. Ovarian cyp19a1a mRNA, aromatase protein, and aromatase activity, however, was less responsive to E2 than brain. Treatment of fish with an aromatase inhibitor fadrozole for 6 days attenuated both brain and ovarian cyp19a1 mRNAs expression and stimulatory effects of E2 was also significantly reduced. These results indicate that expression of cyp19a1b in brain and cyp19a1a in ovary of adult female A. testudineus was closely associated to plasma E2 levels and seasonal reproductive cycle. Results further show apparent differential regulation of cyp19a1a and cyp19a1b expression by E2/fadrozole manipulation.
细胞色素 P450arom（CYP19）是 cyp19a1 基因的产物，催化雄激素向雌激素的转化，是脊椎动物生殖功能调节所必需的。本研究从成年雌性黄颡鱼（Anabas testudineus）卵巢和脑中分离出部分 cDNA 编码卵巢（cyp19a1a）和脑（cyp19a1b）P450arom 基因，并研究了它们在体内受雌激素的调节。结果表明，cyp19a1a 和 cyp19a1b 分别在卵巢和脑中占优势，两者的数量都与生殖周期相适应。为了阐明雌激素对脑 cyp19a1b 和卵巢 cyp19a1a 表达的调节作用，我们在卵黄生成期鱼类中进行了雌激素的剂量和时间依赖性研究，同时存在或不存在特定的芳香化酶抑制剂 fadrozole。结果表明，用 17β-雌二醇（E2；1.0 μM）处理鱼类 6 天，可导致脑 cyp19a1b 转录物、芳香化酶 B 蛋白和芳香化酶活性显著上调，呈剂量和时间依赖性。然而，卵巢 cyp19a1a mRNA、芳香化酶蛋白和芳香化酶活性对 E2 的反应性低于脑。用芳香化酶抑制剂 fadrozole 处理鱼类 6 天可减弱脑和卵巢 cyp19a1a mRNA 的表达，E2 的刺激作用也明显降低。这些结果表明，成年雌性 A. testudineus 脑和卵巢中 cyp19a1b 和 cyp19a1a 的表达与血浆 E2 水平和季节性生殖周期密切相关。结果进一步表明，E2/fadrozole 处理对 cyp19a1a 和 cyp19a1b 表达的调节存在明显差异。
