天敌昆虫蠋蝽线粒体基因组蛋白编码基因分析

Analysis of Protein Coding Genes in Mitochondrial Genome of a Natural Enemy,Arma custos

为了寻找捕食性天敌昆虫在适应环境变化及进化过程中所遗留的痕迹、了解益蝽亚科群体间的分化程度及适应性选择,以蠋蝽13个线粒体蛋白编码基因为分析对象,利用软件Geneious 8.0.4、MEGA 7.0、Codon W1.4.2以及SPSS 26.0等多种生物学软件对蠋蝽13个蛋白编码基因的核苷酸组成、同义密码子相对使用度、有效密码子数和蛋白质性质进行分析,并构建蝽科的系统发育树来探讨蠋蝽的亲缘关系。结果显示,蠋蝽具有很强的AT偏好性;有效密码子数(ENC)结果显示,除黑益蝽外其余均具有较强的密码子偏好性,同义密码子相对使用度显示,密码子的第3位更偏好以A/T结尾;ENC绘图、奇偶图和中性图分析显示,突变压力和自然选择都会影响其密码子使用偏好,其中自然选择是主要作用;系统发育分析结果表明,蛋白编码基因在物种的系统进化关系中具有与形态特征同样的重要性。蠋蝽的蛋白编码基因分析显示,自然选择是影响其密码子偏好性的主要因素,而亲缘关系越近的物种其密码子的使用模式相似度越高,因此,蛋白编码基因在分析物种形成和种群分化中发挥着重要作用。

In order to find the traces left by predatory natural enemies in the process of adaptation to environmental changes and evolution,and to understand the degree of differentiation and adaptive selection among Asopinae,in this study,13mitochondrial protein coding genes of Arma custos were taken as the analytic objects,by using the biological software such as Geneious 8.0.4,MEGA 7.0,Codon W1.4.2 and SPSS 26.0,the nucleotide composition,the relative use of synonymous codons,the number of effective codons,and protein properties of 13 protein coding genes in the mitochondrial genome of Arma custos were analyzed,and the phylogenetic tree of Pentatomidae was constructed to explore the genetic relationship of Arma custos.Nucleotide composition analysis showed that Arma custos had strong AT preference.Comparison of effective codon number(ENC)showed that Asopinae had strong codon preference(except Picromerus griseus).The relative use of synonymous codons indicated that the third bit of the codon was more likely to end with A/T.Enc-plot,Parity plot,and Neutrality plot analysis showed that both mutation pressure and natural selection could affect codon usage preference,and natural selection played a major role.Phylogenetic analysis showed that protein coding genes were as important as morphological characteristics in phylogenetic relationships of species.In conclusion,the analysis of protein coding genes of Arma custos showed that natural selection was the main factor affecting its codon preference.However,the closer the kinship of species were,the higher the similarity of the codon usage patterns was.Therefore,protein coding genes played an important role in the analysis of species formation and population differentiation.