串联重复序列在琴叶拟南芥基因组中的特征探究

Characteristics of Tandem Repeats in Arabidopsis lyrata Genome

串联重复序列广泛存在于真核生物的基因组中,它通过影响染色质的空间结构及基因表达从而影响生物的遗传与进化。本研究以琴叶拟南芥(Arabidopsis lyrata)基因组为材料,分析了1~50 bp重复单元的串联重复序列特征。研究发现串联重复序列在基因的5'UTR和启动子区域密度最高(8757 bp/Mb,8430 bp/Mb),而编码区CDS的密度最低(2406 bp/Mb)。基因组中重复模体最高的为单核苷酸重复的T/A碱基,5'UTR中包含大量的二核苷酸重复模体,而在CDS中主要是三核酸重复模体。串联重复序列特征在琴叶拟南芥基因组不同区域的差别,显示其与基因表达和调控功能相适应。本研究深入探讨了串联重复序列在植物基因组中的特征及作用,为重复序列调控基因表达及植物基因组进化提供借鉴。

Tandem repeats(TRs)exist widely in the genomes of eukaryotes,which influence inheritance and evolution of organisms by affecting the spatial structure of chromatin and participating in the processes of gene expression.The paper analyzed the 1~50 bp repeating units of TR characteristics in Arabidopsis lyrata genome.The results showed that the highest densities were in 5'UTR and promoter regions(8757 bp/Mb and 8430 bp/Mb,respectively),and the lowest density was in CDS region(2406 bp/Mb).T/A bases in single nucleotide repeat motifs showed the highest density in the genome,and dinucleotide repeat units were the highest in 5'UTR,while CDS mainly contained trinucleotide repeating units.The differences of TR characteristics among different regions were closely connected with gene expression and regulation.The study would deepen our understanding on TR characteristics and functions in plant genomes,and would provide references on TRs in gene expression and plant genome evolution.