三斑石斑鱼(Epinephelus trimaculatus)两种芳香化酶cDNA的克隆及其表达的组织特异性

IDENTIFICATION AND EXPRESSION OF TWO CYTOCHROME P450 AROMATASE GENES IN THREESPOT GROUPER EPINEPHELUS TRIMACULATUS

通过设计引物,从三斑石斑鱼的卵巢中克隆鉴定出性腺芳香化酶(EtP450arom a)和脑芳香化酶(EtP450arom b)的cDNA序列,EtP450arom a开放阅读框为1557bp,编码519个氨基酸残基;EtP450arom b开放阅读框为1530bp,共编码510个氨基酸残基;性腺芳香化酶(EtP450arom a)和脑芳香化酶(EtP450arom b)的氨基酸序列的同源性为63.3%,并且包含了芳香化酶经典的功能保守结构。构建了芳香化酶的系统进化树。采用半定量RT-PCR方法研究了性腺芳香化酶(EtP450arom a)和脑芳香化酶(EtP450arom b)在雌性成鱼各组织中的mRNA的表达情况。组织表达结果显示,性腺芳香化酶EtP450arom a只在性腺中特异性表达,而脑芳香化酶EtP450arom b主要在脑区和垂体中表达,表明三斑石斑鱼两种芳香化酶基因的组织特异性及功能的差异。

In the present study, The eDNA sequences encoding two distinct cytochrome P450 Aromatases were cloned from ovary of threespot grouper Epinephelus trimaculatus, and named as EtP450arom a and EtP450arom b. The open reading frame （ORF） of EtP450arom a cDNA is 1557bp in length, encoding 519 amino acids. The EtP450arom b contains an ORF of 1530bp, which translate to a putative protein of 510 amino acids. Sequence analysis showed that the two P450arom genes of threespot grouper shared 63.3% identity with each other, and possessed the typical conservative structures as other species. Phylogenetic analysis revealed that the P450 Aromatases of threespot grouper showed close relation to other perciforrnes, agreeing with the analyzed by traditional morphology and biochemistry in their evolution status. RT-PCR was used to detect the tissue expression in the adult female threespot grouper, and the result showed that the transcription signal of EtP450arom was only observed in ovary with a special expression matter, and the EtP450arom b mainly expressed in brain and pituitary, indicating the tissue specification and functional diversity of cytochrome P450 Aromatases in threespot grouper E. trimaculatus.