10种昆虫过氧化氢酶基因的全基因组鉴定与特征预测

Genome-Wide Identification and Prediction of Characteristics on Catalase Genes in Ten Insect Species

【目的】在全基因组水平上鉴定10种具有代表性昆虫的过氧化氢酶(CAT)基因,并对鉴定所得CAT基因的基本特征和系统发育关系分别进行预测和分析。【方法】在NCBI数据库中下载CAT氨基酸序列作为询问序列,通过本地Blast方法在10种昆虫全基因组水平搜索和鉴定CAT基因并命名。通过生物信息学方法预测10种昆虫CAT家族基因的特征、氨基酸同源序列一致率、保守结构域等。通过MEGA-X软件用最大似然法推断10种昆虫的CAT基因的系统发育。【结果】共鉴定得到23个CAT基因,内华达古白蚁(Zootermopsis nevadensis)、东亚飞蝗(Locusta migratoria)、人虱(Pediculus humanus)、苜蓿蓟马(Frankliniella occidentalis)、茶翅蝽(Halyomorpha halys)、赤拟谷盗(Tribolium castaneum)、黑腹果蝇(Drosophila melanogaster)、冈比亚按蚊(Anopheles gambiae)、家蚕(Bombyx mori)和意大利蜜蜂(Apis mellifera)基因组上分别有3,1,1,1,4,3,2,1,6和1个CAT基因,均具有全长的转录组序列,编码406~553个氨基酸,氨基酸分子量为46.0~63.7kDa,等电点为5.21~9.19。鉴定得到的CAT基因共有122个外显子,99个内含子,且外显子与内含子分布模式在物种间差异较大而种内的CAT基因结构相似。有7个CAT基因编码有信号肽,信号肽包含17~22个氨基酸残基。所有CAT基因编码的氨基酸序列的N端具有1个由17个氨基酸组成的CAT近端活性区域,而C端由9个氨基酸组成的CAT血红素配体区域所组成;其中家蚕的BmCat2基因中单独含有1个细菌胞外溶质结合区域。10种昆虫的CAT1基因具有1∶1的直系同源关系,家蚕出现特异性扩增独立形成支系,与CAT1支系互为姐妹群。【结论】研究结果提供了10个代表性昆虫CAT基因的基础信息,为进一步开展该基因的功能研究奠定了基础。

[Purposes]The catalase genes of 10 representative insects were identified at the genome-wide level,and the basic characteristics and phylogenetic relationships of CATgenes identified were predicted and analyzed respectively.[Methods]The CATamino acid sequences were downloaded from NCBI database as query sequences,and the CATgenes were searched and identified at the genome-wide level of 10 insects by local blast method.The bioinformatics methods were used to predict the characteristics,the consistency of amino acid homologous sequence and conserved domains of CATfamily genes of 10 insect species.The phylogeny of CAT genes in 10 insect species was inferred by maximum likelihood method with MEGA-X software.[Findings]A total of 23 CATgenes were identified,the genomes of Zootermopsis nevadensis,Locusta migratoria,Pediculus humanus,Frankliniella occidentalis,Halyomorpha halys,Tribolium castaneum,Drosophila melanogaster,Anopheles gambiae,Bombyx mori and Apis mellifera have 3,1,1,1,4,3,2,1,6,and 1 CATgenes,respectively,all of which have full-length transcriptional sequence encoding406~553 amino acids,with the molecular weight of 46.0~63.7 kDa and isoelectric point of 5.21~9.19.The identified CATgene contain 122 exons and 99 introns,and the distribution patterns of exons and introns were significantly different among species,while the CATgene structure within species was similar.Seven CATgenes have signal peptides containing 17~22 amino acid residues.The N-terminal of the amino acid sequence encoded by CATgenes has an CATactive domain composed of 17 amino acids,while the C-terminal is composed of a CATheme-ligand domain composed of 9 amino acids and the BmCat2 gene of B.mori contains a bacterial extracellular solute binding domain.CAT1 gene of 10 insects have 1∶1 orthologous relationship,and the B.mori shows specific expansion to form a branch independently,which is a sister group with the CAT1 branch.[Conclusions]The results provide the basic information of CATgenes in 10 representative insect,and lay a foundation for further study on the function of this gene.