Qi C F, Bonhomme F, Buckler-White A, Buckler C, Orth A, Lander M R, Chattopadhyay S K, Morse H C
Laboratory of Immunopathology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Building 7, Room 304, MSC 0760, Bethesda, Maryland 20892-0760, USA.
Mamm Genome. 1998 Dec;9(12):1049-55. doi: 10.1007/s003359900923.
Alleles at the Fv1 gene of inbred mice confer resistance to infection and spread of vertically or horizontally transmitted murine leukemia viruses (MuLV). The nucleotide sequence of Fv1 bears similarity to the gag of a human endogenous retrovirus, HERV-L, but is more closely related to the gag-coding sequence of a newly described class of HERV-L-related mouse endogenous retroviruses designated MuERV-L. Both observations suggest an origin of Fv1 from endogenous gag sequences. The molecular definition of Fv1 provided an opportunity to determine the phylogeny of the gene among wild mice and its relation to MuERV-L. PCR primers, chosen to include most of the coding region of Fv1 for both the n and b alleles, were used to amplify sequences from animals of the genus Mus, which were then sequenced. Closely related products were obtained from almost all animals examined that evolved after the separation from Rattus, in which the homologous gene was shown to be absent. A phylogenetic tree generated with Fv1 sequence data differs noticeably from that developed with sequence data from other genes. In addition, non-synonymous changes were found to be present twice as frequently as synonymous changes, a fact that departs from the standard behavior of a structural gene. These observations suggest that the Fv1 gene may have been subjected to possible horizontal transfers as well as to positive Darwinian selection.
近交系小鼠Fv1基因的等位基因赋予其对垂直或水平传播的鼠白血病病毒（MuLV）感染和传播的抗性。Fv1的核苷酸序列与人类内源性逆转录病毒HERV-L的gag有相似性，但与新描述的一类与HERV-L相关的小鼠内源性逆转录病毒MuERV-L的gag编码序列关系更密切。这两个观察结果都表明Fv1起源于内源性gag序列。Fv1的分子定义为确定该基因在野生小鼠中的系统发育及其与MuERV-L的关系提供了机会。选择用于扩增n和b等位基因Fv1大部分编码区的PCR引物，用于扩增小家鼠属动物的序列，然后进行测序。几乎所有检测的动物在与大鼠分离后进化出的相关产物都被获得，其中显示不存在同源基因。用Fv1序列数据生成的系统发育树与用其他基因序列数据生成的系统发育树明显不同。此外，发现非同义变化的频率是同义变化的两倍，这一事实与结构基因的标准行为不同。这些观察结果表明，Fv1基因可能经历了可能的水平转移以及正向达尔文选择。
