瘤胃纤毛虫终止密码子研究  

The Stop Codons in Rumen Ciliates

作　　者：张禹 张婷婷[1] 李宗军[1] 姜雨[1] ZHANG YU;ZHANG Tingting;LI Zongjun;JIANG Yu(College of Animal Science and Technology,Northwest A&F University,Yangling 712100)

机构地区：[1]西北农林科技大学动物科技学院,陕西杨凌712100

出　　处：《家畜生态学报》2025年第2期8-13,共6页Journal of Domestic Animal Ecology

摘　　要：密码子是遗传研究的基础,大多生物采用标准密码子,然而在纤毛虫的不同纲间,甚至不同目间,时常存在终止密码子编码氨基酸的现象,这被称为终止密码子重分配。毛口亚纲(Trichostomatia)中的纤毛虫是草食动物胃肠道微生物区系的重要组成部分,其终止密码子的重分配现象尚不清楚,影响了当前草食动物消化道纤毛虫基因组的注释和分析工作。本研究首先通过对瘤胃纤毛虫所属的前庭目(Vestibuliferida)与内毛目(Entodiniomorphida)共计10个物种23个转录组数据进行组装,分别在两个目中筛选出含Poly A结构且能比对到NR数据库的3146条和15250条转录本用于终止密码子鉴定。结果显示两个目的终止密码子均是UAA、UAG和UGA。此外,构建与终止密码子识别相关基因真核释放因子1(eRF1)的系统发育树显示瘤胃纤毛虫eRF1基因与侧口纲(Litostomatea)中采用标准终止密码子的纤毛虫聚在一起。同时,鉴定eRF1基因的关键功能位点,发现瘤胃纤毛虫的主要功能位点与其它使用标准终止密码子的物种一致。eRF1分析结果也间接表明瘤胃纤毛虫使用UAA、UAG和UGA作为终止密码子。瘤胃纤毛虫终止密码子的确定为解析其遗传基础和功能奠定了基础。The genetic codons are the basis of genetic research.Most organisms use the standard codons.However,the“stop codons”coding for an amino acid,termed as stop codons reassignments,often occur among different classes or orders of ciliates.Trichostome ciliates are an important part in the gastrointestinal microflora of herbivores,but their stop codon reassignment is still unclear,which hinders the annotation and analysis of ciliates genomes in the gastrointestinal tract of herbivores.This study assembled 23 transcriptome data of 10 rumen ciliates species from Vestibuliferida and Entodiniomorphida.Among them,3,146 and 15,250 Poly A-capped and NR-mapped transcripts from Vestibuliferida and Entodiniomorphida,respectively,were used for stop codon detection.The results showed that both orders used UAA,UAG and UGA as stop codons.In addition,a phylogenetic tree of the eukaryotic release factor 1(eRF1)gene,which associated with stop codon recognition,demonstrated that the rumen ciliate eRF1 gene was clustered with species in Litostomatea using standard stop codons.The identification of key functional sites in eRF1 gene also showed that the main functional sites of rumen ciliates were consistent with the species using standard stop codons.Analysis of eRF1 gene also indirectly indicate that rumen ciliates use UAA,UAG and UGA as stop codons.Detection of rumen ciliates stop codon lays the foundation for further analysis of the genetic basis and function of rumen ciliates.

关 键 词：瘤胃纤毛虫 终止密码子重分配 eRF1 转录组 

分 类 号：S852.724[农业科学—基础兽医学]