向梅 谢应强 张洪志 李玉艳 王孟卿 臧连生 张礼生

摘要 ：乙酰輔酶A羧化酶（acetyl-CoA carboxylase，ACC）是脂肪酸合成第一步反应的限速酶，参与长链脂肪酸的合成。本试验基于七星瓢虫Coccinella septempunctata L.转录组数据，探究ACC在滞育七星瓢虫脂代谢中的调控作用。利用RT-PCR和RACE技术从七星瓢虫中克隆得到ACC基因全长，命名为CsACC（GenBank登录号：MT012819），该基因cDNA序列全长7 217 bp，开放阅读框（ORF）长为6 792 bp，编码2 263个氨基酸，预测蛋白质分子量为255.9 kDa，理论等电点（pI）为5.90，无跨膜螺旋结构，无信号肽。通过氨基酸多序列比对分析，结果显示CsACC与鞘翅目的赤拟谷盗Tribolium castaneum乙酰辅酶A羧化酶同源性较高。利用实时荧光定量PCR技术检测CsACC基因在七星瓢虫正常发育及滞育诱导不同阶段的相对表达量，结果显示，滞育诱导30 d表达量达到最高，滞育诱导60 d、滞育解除期以及正常发育30 d表达量几乎持平。本研究为揭示CsACC基因在脂代谢通路中的调控作用提供理论依据。

关键词 ：七星瓢虫; 乙酰辅酶A羧化酶; 脂代谢; 基因克隆; 表达分析

中图分类号：

S 476.2

文献标识码： A

DOI： 10.16688/j.zwbh.2020093

Cloning and expression analysis of acetyl-CoA carboxylase in

Coccinella septempunctata

XIANG Mei1，2， XIE Yingqiang2， ZHANG Hongzhi2， LI Yuyan2， WANG Mengqing2，

ZANG Liansheng1*， ZHANG Lisheng2*

（1. Jinlin Agricultural University， Changchun 130118， China; 2. Institute of Plant Protection， Chinese Academy of Agricultural Sciences， Beijing 100193， China）

Abstract

Acetyl-CoA carboxylase （ACC） is a rate-limiting enzyme involved in the first step of fatty acid synthesis. In order to explore the function of ACC in lipid metabolism of Coccinella septempunctata at diapause stage， the full-length cDNA of a ACC gene was cloned using RT-PCR and RACE techniquebased on the transcriptome database. The gene was named CsACC （GenBank accession no. MT012819）. The full length of cDNA sequence of this gene was 7 217 bp and the length of open reading frame （ORF） was 6 792 bp， encoding 2 263 amino acid residues. The predicted molecular weight of the protein was 255.9 kDa with an isoelectric point （pI） of 5.90 without a transmembrane helical structure or signal peptide. The results showed that CsACC had a high homology with that of Tribolium castaneum. The relative expression levels of CsACC gene in different stages of normal and diapause development were detected by real-time fluorescence quantitative PCR. The results showed that the expression levels of CsACC gene reached the highest level on 30th day after diapause induction， and the expression levels were almost flat on 60th day after diapause inductions， 30th day after normal development and after diapause termination. This study provides a theoretical basis for revealing the regulatory role of CsACC gene in the lipid metabolism pathway.

Key words

Coccinella septempunctata; acetyl-CoA carboxylase; lipid metabolism; gene clone; gene expression

七星瓢虫Coccinella septempunctata L.在我国广泛分布，其捕食果树及农作物上的各种蚜虫[12]，是一种典型的捕食性农业害虫天敌，在国内外已被广泛应用[34]。七星瓢虫存在滞育现象，腹部可大量积累脂肪，滞育个体总脂含量较正常发育个体显著增加[5]。根据此现象，本研究通过七星瓢虫转录组数据分析比对正常发育组、滞育组及滞育解除组，筛选得到脂代谢中滞育关联基因，研究差异表达基因，为揭示滞育分子机制提供理论依据[67]。

昆虫脂肪体是维持体内能量平衡的动力来源，也是在变态过程中长时间不进食时脂肪的必要储藏库。……