Hughes Austin L
Department of Biological Sciences, University of South Carolina, Coker Life Sciences Bldg., 700 Sumter St., Columbia, SC 29208, USA.
Gene. 2007 May 1;392(1-2):266-72. doi: 10.1016/j.gene.2006.12.038. Epub 2007 Jan 24.
In the seven protein-coding genes in the Marburg virus (MARV) genome, the synonymous nucleotide diversity substantially exceeded the nonsynonymous nucleotide diversity, indicating strong purifying selection. Likewise, there was evidence of purifying selection on 5'UTR and 3'UTR, where nucleotide diversity (pi) was significantly less than piS in the coding regions. Nonsynonymous polymorphic sites showed significantly reduced mean gene diversity in comparison to other polymorphic sites, indicating that purifying selection at certain slightly deleterious nonsynonymous polymorphisms is ongoing. Moreover, nonsynonymous polymorphic sites showed significantly reduced gene diversity in comparison to adjacent synonymous sites, even though the vast majority of such adjacent synonymous sites were in the same codon or an adjacent codon. Thus purifying selection, in conjunction with recombination and/or backward mutation, can act to break up linkage relationships at a micro-scale in the MARV genome. The ability of purifying selection to break up linkage between synonymous and nonsynonymous polymorphisms on such a fine scale has not been reported in any other genome.
在马尔堡病毒（MARV）基因组的7个蛋白质编码基因中，同义核苷酸多样性显著超过非同义核苷酸多样性，表明存在强烈的纯化选择。同样，在5'UTR和3'UTR上也有纯化选择的证据，其核苷酸多样性（pi）显著低于编码区的piS。与其他多态性位点相比，非同义多态性位点的平均基因多样性显著降低，这表明针对某些轻微有害的非同义多态性的纯化选择正在进行。此外，与相邻的同义位点相比，非同义多态性位点的基因多样性显著降低，尽管绝大多数此类相邻同义位点位于同一密码子或相邻密码子中。因此，纯化选择与重组和/或反向突变共同作用，可以在微观尺度上打破MARV基因组中的连锁关系。纯化选择在如此精细的尺度上打破同义与非同义多态性之间连锁的能力在其他任何基因组中均未被报道。
