野桑蚕CYP305B1V1基因的克隆与序列分析

对野桑蚕CYP305B1V1基因进行克隆和序列分析的结果显示,野桑蚕CYP305B1V1基因的ORF为1 464nt,编码487 aa;同源性分析表明,在DNA水平上野桑蚕CYP305B1V1基因与家蚕CYP305B1基因的同源性达99%,与推导的氨基酸序列完全一致。通过和NCB I中家蚕基因组数据比对和拼接,预测野桑蚕CYP305B1V1基因结构中至少含有6个内含子,且内含子与外显子之间的连接符合GT-AT法则。

家蚕P450基因CYP305B1的基因组序列克隆及结构分析

为了研究家蚕P450基因CYP305B1的结构,采用反向PCR技术克隆了家蚕CYP305B1基因的基因组序列,经序列测定,拼接得到家蚕CYP305B1全基因序列,发现家蚕CYP305B1的第1内含子位于5′端非翻译区序列(5′-UTR)中间。将家蚕CYP305B1与野桑蚕P450基因CYP305B1V1序列进行同源性比较的结果表明,二者在5′-UTR上游-400～-770 bp序列间的同源性只有40.4%,序列差异最大的是第1内含子和第6内含子。在第1内含子中,野桑蚕CYP305B1V1在翻译起始密码ATG上游-340之前存在330 bp的插入序列,在-110～-340 bp间二者的同源性也只有46.9%;在第6内含子中,家蚕CYP305B1比野桑蚕CYP305B1V1多了一段约300 bp的插入序列。研究结果有助于进一步探究该基因的转录和调控机制。

野桑蚕不同组织细胞色素P450 CYP305 B1 V1基因的诱导表达特征研究

[目的]研究不同诱导物对野桑蚕各组织中细胞色素P450 CYP305 B1 V1基因表达的影响。[方法]参照GenBank中公布的野桑蚕CYP305 B1 V1基因的mRNA序列,设计1对引物,采用半定量RT-PCR方法分析经NaF、芸香苷、氯氰菊酯和蜕皮激素处理的野桑蚕各组织中CYP305 B1 V1基因的表达情况,并对该基因的氨基酸序列进行同源性比较和进化分析。[结果]氯氰菊酯、芸香苷和NaF影响野桑蚕CYP305 B1 V1基因在组织中的表达,蜕皮激素无明显影响。氨基酸的同源性分析表明该基因氨基酸序列与家蚕CYP305B1的氨基酸序列同源性最高(100%);与赤拟谷盗推测的CYP305 A1、蜜蜂推测的CYP305 A1、果蝇CYP305 A1、冈比亚按蚊CYP305 A2及库蚊CYP2L1有较高的同源性。[结论]野桑蚕CYP305 B1 V1基因可能主要参与外源性化合物的代谢,对揭示细胞色素P450的功能和不同药物的代谢机理具有重要意义。

Induced Expression of Cytochrome P450 CYP305 B1V1 Gene in Different Tissues of Wild Mulberry Silkworm(Bombyx mandarina)

[ Objective] The aim of this study was to investigate effects of various inducers on the expression of cytochrome P450 CYP305 B1 V1 Gene in different tissues of wild mulberry silkworm. [ Method] Referring to the mRNA sequence of CYP305 B1 V1 Gene published in GenBank for wild mulberry silkworm, one pair of primers was designed, and the expression of cytochrome P450 CYP305 B1 V1 Gene in different tissues of wild mulberry silkworm treated by NaF, rutin, cypermethrin and ecdysone was also analyzed by the semi - quantitative RT - PCR. Furthermore, homology comparison and phylogenetic analysis for amino acid sequences of this gene were studied. [ Result] Rutin, cypermethrin and NaF had effects on the expression of P450 CYP305 B1 V1 Gene in different tissues of wild mulberry silkworm, while ecdysone had no significant effect. Homology comparison for amino acids indicated that the amino acid sequence of this gene was the most similar to that of CYP305 B1 gene in Bombyx mori with 100% amino acid identity, and highly similar to those of Tribolium casmneum CYP305A1, Apis mellifera CYP305A1, Drosophi- la melanogaster CYP305A1, Anopheles gambiae CYP305A2and Culex pipiens quinquefasciatus CYP2LI. [ Conclusion] CYP305 B1 V1 Gene of wild mulberry silkworm is likely to mainly take part in the metabolism of exogenous compounds, which is of great significance for revealing the function of cytochrome P450 and the metabolic mechanism of different drugs.