Lusis A J, Tomino S, Paigen K
Biochem Genet. 1977 Feb;15(1-2):115-22. doi: 10.1007/BF00484554.
Previous studies have suggested that the binding of mouse flucuronidase to endoplasmic reticulum membrane is stabilized by the membrane protein egasyn. Using a radioimmunoassay for egasyn, we have now examined the inheritance of egasyn levels in mice. Mice of the inbred strain C57BL/6J, which have normal levels of microsomal glucuronidase, contained 56 +/- 10 mug egasyn per gram of liver. Mice of the inbred strain YBR, which carry the Eg0 mutation resulting in the absence of microsomal glucuronidase, did not contain detectable levels of egasyn. The F1 progeny of these two strains contained intermediate levels of egasyn, 25 +/- 4 mug egasyn per gram of liver. Progeny from the backcross of these F1 animals to YBR were distributed equally into two discrete phenotypic classes. One class lacked both egasyn and microsomal glucuronidase, while the other class contained 25 +/- 3 mug egasyn per gram of liver and contained normal levels of microsomal glucuronidase. Thus egasyn levels are determined by the Eg locus and show additive inheritance. These results suggest that the Eg gene codes for egasyn and that it is the inability to produce egasyn that results in a deficiency of microsomal glucuronidase in the Eg0 mutant.
以往的研究表明，小鼠葡糖醛酸酶与内质网膜的结合通过膜蛋白egasyn得以稳定。我们现在使用针对egasyn的放射免疫分析法，研究了小鼠中egasyn水平的遗传情况。近交系C57BL/6J小鼠的微粒体葡糖醛酸酶水平正常，每克肝脏含56±10微克egasyn。近交系YBR小鼠携带Eg0突变，导致微粒体葡糖醛酸酶缺失，未检测到egasyn水平。这两个品系的F1后代中egasyn水平处于中间值，每克肝脏含25±4微克egasyn。这些F1动物与YBR回交的后代被平均分为两个不同的表型类别。一类既缺乏egasyn也缺乏微粒体葡糖醛酸酶，而另一类每克肝脏含25±3微克egasyn，且微粒体葡糖醛酸酶水平正常。因此，egasyn水平由Eg位点决定，并呈现加性遗传。这些结果表明，Eg基因编码egasyn，正是无法产生egasyn导致了Eg0突变体中微粒体葡糖醛酸酶的缺乏。
