Liu Xusheng, Liang Bing, Zhang Shuyi
Institute of Zoology, Chinese Academy of Sciences, Beijing 100080, PR China.
Gen Comp Endocrinol. 2004 Sep 15;138(3):247-54. doi: 10.1016/j.ygcen.2004.04.005.
In this study, a cDNA encoding cytochrome P450 aromatase (P450arom) was cloned from black porgy Acanthopagrus schlegeli ovary. The deduced amino acid sequence had high homology with ovarian P450arom of other teleost fish. Moreover, we partially cloned two FTZ-F1 homologues (asff1a and asff1b) from black porgy. Comparative sequence analysis grouped asff1a and asff1b in NR5A2 and NR5A4 clades, respectively. Among the various tissues tested, P450arom mRNA was highly expressed in the ovary and weakly in the brain and testis, asff1a was expressed in brain, liver, intestine, kidney, testis, and ovary, asff1b was expressed in brain, kidney, testis, and ovary. The transcript levels of P450arom, asff1a, and asff1b were measured in the ovary and testis of 1+ -year-old, 2+ -year-old, and 5+ -year-old black porgy. The transcript level of P450arom in the ovary of 2+ -year-old fish was significantly higher than those of 1+ -year-old and 5+ -year-old fish. The results suggest that P450arom gene may be involved in the mechanism of natural sex change of protandrous black porgy. No change in ovarian expression of asff1a or asff1b was observed among different ages. These results suggest that up-regulation of the transcript levels of P450arom during the course of natural sex change of black porgy was not regulated via FTZ-F1.
在本研究中，从黑鲷（Acanthopagrus schlegeli）卵巢中克隆了编码细胞色素P450芳香化酶（P450arom）的cDNA。推导的氨基酸序列与其他硬骨鱼类的卵巢P450arom具有高度同源性。此外，我们从黑鲷中部分克隆了两个FTZ-F1同源物（asff1a和asff1b）。比较序列分析将asff1a和asff1b分别归入NR5A2和NR5A4进化枝。在测试的各种组织中，P450arom mRNA在卵巢中高表达，在脑和睾丸中低表达，asff1a在脑、肝、肠、肾、睾丸和卵巢中表达，asff1b在脑、肾、睾丸和卵巢中表达。在1龄、2龄和5龄黑鲷的卵巢和睾丸中测量了P450arom、asff1a和asff1b的转录水平。2龄鱼卵巢中P450arom的转录水平显著高于1龄和5龄鱼。结果表明，P450arom基因可能参与了雄性先熟黑鲷自然性逆转的机制。在不同年龄组中，未观察到asff1a或asff1b在卵巢中的表达变化。这些结果表明，黑鲷自然性逆转过程中P450arom转录水平的上调不是通过FTZ-F1调节的。
