Ryffel G U, Muellener D B, Gerber-Huber S, Wyler T, Wahli W
Nucleic Acids Res. 1983 Nov 25;11(22):7701-16. doi: 10.1093/nar/11.22.7701.
We have analyzed middle repetitive DNA in the albumin and vitellogenin gene families of Xenopus laevis. Mapping specific repetitive DNA sequences derived from introns of the A1 vitellogenin gene reveals that these sequences are scattered within and around the four vitellogenin genes (A1, A2, B1 and B2) and the two albumin genes (74 kd and 68 kd). Three repetitive DNA elements present in the A1 vitellogenin transcriptional unit are also located in introns of the 74 kd albumin gene. This apparently random distribution of middle repetitive DNA in the two gene families suggests that the analyzed sequences are not involved in gene regulation, but rather that they might represent unstable genetic elements. This hypothesis is further supported by the finding that size polymorphism in the A1 vitellogenin gene and in the 74 kd albumin gene is correlated with the presence or absence of repetitive DNA.
我们分析了非洲爪蟾白蛋白和卵黄蛋白原基因家族中的中度重复DNA。对源自A1卵黄蛋白原基因内含子的特定重复DNA序列进行定位，结果显示这些序列散布在四个卵黄蛋白原基因（A1、A2、B1和B2）以及两个白蛋白基因（74kd和68kd）之内及周围。A1卵黄蛋白原转录单元中存在的三个重复DNA元件也位于74kd白蛋白基因的内含子中。中度重复DNA在这两个基因家族中的这种明显随机分布表明，所分析的序列不参与基因调控，相反，它们可能代表不稳定的遗传元件。A1卵黄蛋白原基因和74kd白蛋白基因中的大小多态性与重复DNA的存在与否相关，这一发现进一步支持了这一假说。
