Correlation between messenger RNA expression of cytochrome p450 aromatase and its enzyme activity during oocyte development in the red seabream (Pagrus major)
Correlation between messenger RNA expression of cytochrome p450 aromatase and its enzyme activity during oocyte development in the red seabream (Pagrus major)
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DOI：
10.1095/biolreprod65.4.1186
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发表时间：
2001-10-01
影响因子：
3.6
通讯作者：
Kagawa, H
中科院分区：
文献类型：
--
作者：
Gen, K;Okuzawa, K;Kagawa, H
在硬骨鱼中，雌二醇-17 β（E-2）是负责卵母细胞发育的重要激素。为了阐明E-2生物合成的分子机制，我们对直接参与E-2生物合成的真鲷（Pagrus major）细胞色素P450芳香化酶（P450（arom））的结构进行了表征，并发现在卵母细胞发育过程中，促性腺激素释放激素类似物的植入诱导了P450（arom）mRNA水平的变化。编码P450（arom）的cDNA克隆的长度为1779个碱基对，并且编码长度为519个氨基酸的蛋白质，计算的分子量为58.9kDa。北方印迹分析表明，P450（arom）mRNA水平从第8天开始逐渐增加，当卵母细胞达到次级卵黄球阶段，并维持在高水平，在产卵当天（15天）。P450（arom）mRNA水平增加与性腺指数（性腺重量/体重× 100%）、血清E-2和P450（arom）酶活性（卵巢碎片中睾酮体外转化为E-2）增加相关。此外，在卵巢发育过程中，LH β mRNA水平的增加与P450（arom）mRNA水平的增加相关，而FSH β mRNA水平的增加与P450（arom）mRNA水平无关。此外，在卵黄发生卵母细胞生长过程中，P450（arom）mRNA在离体卵泡中表达增加，而在移行核期和成熟期卵泡中检测不到。这些研究结果，加上那些以前的研究表明，LH，而不是FSH，可能通过增加P450（arom）mRNA水平调节E-2的生物合成过程中的卵母细胞发育的红海鸟。
In teleosts, estradiol-17 beta (E-2) is an important hormone responsible for oocyte development. To elucidate the molecular mechanisms underlying E-2 biosynthesis, we characterized the structure of red seabream (Pagrus major) cytochrome P450 aromatase (P450(arom)) that is directly involved in E-2 biosynthesis and found changes in mRNA levels of P450(arom) during oocyte development induced by implantation of gonadotropin-releasing hormone analogue. A cDNA clone encoding P450(arom) is 1779 base pairs in length and encodes a protein of 519 amino acids in length, with a calculated molecular weight of 58.9 kDa. Northern blot analysis showed that P450(arom) mRNA levels increased gradually from Day 8, when oocytes reached the secondary yolk globule stage, and were maintained at high levels at the day of spawning (Day 15). The P450(arom) mRNA levels increased in association with an increase of the gonadosomatic index (gonad weight/body weight x 100%), serum E-2, and P450(arom) enzyme activity (in vitro conversion of testosterone to E-2 in the ovarian fragments). Furthermore, an increase in mRNA levels of the LH beta, but not FSH beta, correlated with increased P450(arom) mRNA levels during the course of ovarian development. in addition, the levels of P450(arom) mRNA increased in isolated ovarian follicles during the course of vitellogenic oocyte growth and became undetectable in follicles at the migratory nucleus and the mature stages. These findings, together with those of the previous studies, suggest that LH, not FSH, may regulate E-2 biosynthesis via increased levels of P450(arom) mRNA during oocyte development of red seabream.