异色瓢虫与七星瓢虫细胞色素P450、抗菌肽和溶菌酶基因的鉴定及表达分析

Identification and expression analysis of cytochrome P450, antimicrobial peptide and lysozyme genes in multicolored Asian lady beetle Harmonia axyridis and sevenspotted lady beetle Coccinella septempunctata

中文关键词:异色瓢虫  七星瓢虫  抗菌肽  溶菌酶  细胞色素P450  免疫

keywords:Harmonia axyridis  Coccinella septempunctata  antimicrobial peptide  lysozyme  cytochrome P450  immune

中文摘要:为探究异色瓢虫Harmonia axyridis环境竞争力的来源，以七星瓢虫Coccinella septempunctata为对照，采用同源比对法对两者细胞色素P450（cytochrome P450，CYP450）、抗菌肽和溶菌酶基因进行鉴定，并对差异表达基因进行分析和荧光定量PCR验证。结果显示，在异色瓢虫中共发现89个CYP450基因、25个抗菌肽基因和18个溶菌酶基因；在七星瓢虫中共发现127个CYP450基因、17个抗菌肽基因和9个溶菌酶基因。异色瓢虫编码抗菌肽和溶菌酶的基因较七星瓢虫存在明显的扩增，而CYP450基因的扩增少于七星瓢虫，表明抗菌肽家族在异色瓢虫环境竞争过程中有着更重要的作用；通过转录组的差异表达分析以及荧光定量PCR验证，发现大部分抗菌肽和溶菌酶基因在脂肪体中高表达，据此推测脂肪体为2种瓢虫抗菌肽等免疫因子的主要合成场所。

Abstract:To explore the source of environmental competitiveness in multicolored Asian lady beetle Harmonia axyridis, sevenspotted lady beetle Coccinella septempunctata was selected as control, cytochrome P450 (CYP450), antimicrobial peptide (AMP), and lysozyme genes were identified by homology comparison and domain comparison, and the differentially expressed genes were analyzed and verified by qPCR. The results showed that total 89 CYP450, 25 AMPs, and 18 lysozyme genes were identified in H. axyridis, while 127, 17, and nine identified in C. septempunctata. The significantly more genes encoding AMPs and lysozymes were found in H. axyridis than in C. septempunctata suggested that AMPs might play a more important role in environmental competition of H. axyridis. Through transcriptome differential expression analysis and qPCR, the high expression level of AMPs and lysozymes in the fat body was found. All the results indicated that the fat body was probably the main synthesis site of immune factors such as AMPs.