Scott C L, Potter M
J Immunol. 1984 May;132(5):2638-43.
The complement of Ig V lambda genes in nine species of feral mice representing the four extant subgenera of the genus Mus was examined and compared with that of BALB/c inbred mice. Although all inbred strains examined have two V lambda genes, there is variation in the number of copies of V lambda genes in the wild mice. All feral representatives of M. musculus domesticus, from which inbred strains are derived, have at least three V lambda genes, indicating that a V lambda gene may have been lost during the inbreeding process. At least three V lambda genes are also found in representatives of three other M. musculus subspecies, including the stock of M. musculus musculus "Czech II" shown to have at least 12 C lambda genes. In comparing the complement of V lambda and C lambda genes in these animals, evidence is found that supports a mechanism of lambda gene reiteration involving duplication of a unit containing a V lambda and two C lambda genes. However, the possibility that C lambda gene amplification occurred independent of V lambda gene evolution cannot be ruled out. M. spicelegus and M. spretus, species that are semifertile with M. musculus, have one to three V lambda genes. Species more distantly related to M. musculus, such as M. cookii and M. platythrix, appear to have more (four to six) V lambda genes. Greater V lambda gene heterogeneity is also found in these animals. We propose that the ancestors of the subgenus Mus had more V lambda genes than are seen in modern species and that the paucity of V lambda genes in M. musculus, M. spicelegus, and M. spretus may be the result of V lambda gene deletion events that occurred since the divergence of the ancestor of these three species and those of the distantly related species.
研究并比较了代表小家鼠属四个现存亚属的九种野生小鼠的Ig Vλ基因互补情况，以及与BALB/c近交系小鼠的该基因互补情况。尽管所有检测的近交系都有两个Vλ基因，但野生小鼠中Vλ基因的拷贝数存在差异。家鼠（近交系即由此衍生而来）的所有野生代表至少有三个Vλ基因，这表明在近交过程中可能丢失了一个Vλ基因。在其他三个小家鼠亚种的代表中也发现至少有三个Vλ基因，包括小家鼠指名亚种“捷克II系”，该品系已显示至少有12个Cλ基因。在比较这些动物的Vλ和Cλ基因互补情况时，发现了支持λ基因重复机制的证据，该机制涉及一个包含一个Vλ和两个Cλ基因的单元的复制。然而，不能排除Cλ基因扩增独立于Vλ基因进化而发生的可能性。与小家鼠半可育的斯氏小家鼠和西班牙小家鼠有一至三个Vλ基因。与小家鼠亲缘关系更远的物种，如库克氏小家鼠和平颅小家鼠，似乎有更多（四至六个）Vλ基因。在这些动物中也发现了更大的Vλ基因异质性。我们提出，小家鼠亚属的祖先比现代物种拥有更多的Vλ基因，小家鼠、斯氏小家鼠和西班牙小家鼠中Vλ基因的稀少可能是由于这三个物种的祖先与亲缘关系较远的物种的祖先分化后发生的Vλ基因缺失事件所致。
