Comparative genomic analysis of C-type lectin-domain genes in seven holometabolous insect species
Comparative genomic analysis of C-type lectin-domain genes in seven holometabolous insect species
复制标题
七种全代谢昆虫 C 型凝集素结构域基因的比较基因组分析
DOI：
10.1016/j.ibmb.2020.103451
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发表时间：
2020-11-01
影响因子：
3.8
通讯作者：
Yu, Xiao-Qiang
中科院分区：
文献类型：
--
作者：
Lu, Yuzhen;Su, Fanghua;Yu, Xiao-Qiang
C型凝集素（CTL）通过糖识别结构域（CRD）识别各种糖复合物，在免疫应答中发挥重要作用。在这项研究中，比较基因组分析的CTL在7个全变态物种。CTL-S1 ~ S8和CTL-X1 ~ X4的正向同源群在7种昆虫中都存在，而CTL-X5的双CRD群、CTL-S11的三CRD群、CTL-S9的长C端群和鳞翅目昆虫特有的CTL-S10群则不保守。SliCTL-S12-S14簇仅在斜纹夜蛾中存在，而CTL-S基因在果蝇的2L和2 R染色体上均有扩增。大多数IMLs被聚成三组，IMLs的数量因物种而异，由于基因重复。D.三组中的每一组内的黑腹动物特异性CTL和鳞翅目IML进化得更快，具有更高的dN/dS比率。IMLs中的两个CRD聚成两个分支，第一和第二CRD分别具有保守的Cys 4-Cys 5和Cys 1-Cys 2键。S.斜纹夜蛾主要在5龄幼虫的脂肪体中表达，而在6龄幼虫的脂肪体中不表达;斜纹夜蛾核型多角体病毒（SpltNPV）和莱氏野村病毒（Nomuraea rileyi）感染。在SpltNPV感染的中后期，脂肪体中表达而血细胞中不高表达的SliCTLs的转录水平降低，血细胞中高表达或特异表达的SliCTLs的mRNA水平主要被SpltlNPV、N. rileyi和苏云金杆菌感染。这些结果为进一步研究CTL在宿主-病原体相互作用中的功能提供了有价值的信息。
C-type lectins (CTLs) recognize various glycoconjugates through carbohydrate recognition domains (CRDs) and they play important roles in immune responses. In this study, comparative genomic analysis of CTLs were performed in 7 holometabolous species. CTL-S1 to S8 and CTL-X1 to X4 orthologous groups existed in the 7 species, while CTL-X5 group with dual-CRD, CTL-S11 group with triple-CRD, CTL-S9 group with a long C-terminus and Lepidopteran specific CTL-S10 group were not conserved. SliCTL-S12 to S14 cluster was only present in Spodoptera litura, and CTL-S genes were expanded on chromosomes 2 L and 2 R in Drosophila melanogaster. Most IMLs were clustered into three groups and the numbers of IMLs vary among species due to gene duplications. D. melanogaster specific CTLs and Lepidopteran IMLs within each of the three groups evolved more rapidly with higher dN/dS ratios. Two CRDs in IMLs clustered into two clades, with conserved Cys4-Cys5 and Cys1-Cys2 bonds in the first and second CRDs, respectively. The CTL-S and CTL-X family members in S. litura were mainly expressed in the fat body of 5th but not 6th instar larvae, and responded differently to S. litura nucleopolyhedrovirus (SpltNPV) and Nomuraea rileyi infection. The transcription levels of SliCTLs that expressed in fat body but not highly expressed in hemocytes were decreased at the middle and late stages of SpltNPV infection, and the mRNA levels of SliCTLs highly or specifically expressed in hemocytes were mainly decreased by SpltlNPV, N. rileyi and Bacillus thuringiensis infection. These results provide valuable information for further exploration of CTL functions in host-pathogen interaction.