埃博拉病毒基因组中微卫星序列的分布分析

Analysis of Microsatellite Sequence Distribution in Ebolavirus Genomes

微卫星或简单重复序列(simple sequence repeat, SSR)在真核和原核生物以及病毒基因组中普遍存在,并被广泛用于遗传与进化研究。本研究从NCBI中下载埃博拉病毒属的四个不同种的埃博拉病毒全基因组序列,筛选36条作为实验材料,利用IMEx在线提取软件提取SSRs,用Python编程统计数据,从而分析SSRs在埃博拉病毒全基因组序列中的分布情况。分析得出,埃博拉病毒基因组序列中二型SSRs含量最为丰富,其次是一型SSRs,三型SSRs有少量,四型SSRs则更少,没有发现五型和六型SSRs。在更深入的分析中得出在埃博拉病毒属四个种中,含A/T碱基的SSRs含量远远大于含C/G碱基的SSRs。分析得出一型SSRs中(A)n/(T)n远多于(G)n/(C)n,二型SSRs中不存在(GC/CG)n,三型中也不存在(GGC/CGG/GCG/CCG/CGC/GCC) n。上述发现可能跟埃博拉病毒的致病机理有密切联系。通过对埃博拉病毒基因组序列中SSRs的分析,为研究埃博拉病毒的变异情况及致病机制提供更多参考。

Microsatellites or Simple Sequence Repeat,(SSR)are ubiquitous in prokaryotic organism,eukaryotic organism,and viral genome,which have been extensively used for heredity and evolutionary studies.In this study,36 complete genomic sequences of Ebolavirus from 4 species were selected in National Center for Biotechnology Information(NCBI),and SSRs were extracted from these samples through an online extraction software IMEx with statistical work in Python,to analyze of the distribution of SSRs in complete genomes of Ebolavirus.The results showed the content of dinucleotide SSRs(di-SSRs)was the most abundant SSRs in genomic sequences of Ebolavirus,followed by mononucleotide SSRs(mono-SSRs),trinucleotide SSRs(tri-SSRs)and tetranucleotide SSRs(tetra-SSRs),but pentanucleotide SSRs(penta-SSRs)and hexnucleotide SSRs(hex-SSRs)had not been found.Further analysis showed that in 4 species of genus Ebolavirus,the SSRs containing A/T nucleotide had been detected to be more than the SSRs containing C/G nucleotide.The content of(A)n and(T)n in mononucleotide SSRs were much more higher than the content of(G)n and(C)n.There was no(GC/CG)n discovered in dinucleotide SSRs,and also no(GGC/CGG/GCG/CCG/CGC/GCC)n discovered in trinucleotide SSRs.Those discoveries might be closely related to the pathogenic mechanism of the Ebolavirus.By analyzing the SSRs in the genomes of Ebolavirus,this analysis could provide more reference to study the mutation and pathogenic mechanism of the Ebolavirus.