Levi-Strauss M, Tosi M, Steinmetz M, Klein J, Meo T
Proc Natl Acad Sci U S A. 1985 Mar;82(6):1746-50. doi: 10.1073/pnas.82.6.1746.
Mouse liver cDNA clones related to the C4 and C4-Slp isoforms of the fourth component of complement differ by few nucleotide changes within a region of substantial divergence from human C4. It is suggested that the mouse C4 gene duplication is an evolutionarily recent event with respect to the time of mammalian radiation. This conclusion is reinforced by the presence of a single C4 gene in the Syrian hamster. Most H-2 haplotypes, including those characterized by an undetectable C4-Slp protein, possess two C4 gene copies which, in contrast to the neighboring factor B, show a marked restriction site polymorphism. The genetic variation of this region is emphasized by the presence in the mouse of a rare "polymorphism" for C4 gene number. Multiple C4-related gene copies characterize those exceptional wild-derived H-2 haplotypes, H-2w7, H-2w16, and H-2w19, that determine the expression of the C4-Slp protein in female animals.
与补体第四成分的C4和C4-Slp亚型相关的小鼠肝脏cDNA克隆，在与人类C4有显著差异的区域内仅有少数核苷酸变化。有人提出，就哺乳动物辐射时间而言，小鼠C4基因复制是一个近期的进化事件。叙利亚仓鼠中存在单个C4基因，这一结论得到了进一步加强。大多数H-2单倍型，包括那些以无法检测到C4-Slp蛋白为特征的单倍型，都拥有两个C4基因拷贝，与相邻的B因子不同，这些拷贝显示出明显的限制性位点多态性。小鼠中存在罕见的C4基因数量“多态性”，这突出了该区域的遗传变异。多个与C4相关的基因拷贝是那些特殊的野生来源H-2单倍型H-2w7、H-2w16和H-2w19的特征，这些单倍型决定了雌性动物中C4-Slp蛋白的表达。
