Sokoloff D, Hechtman P
Department of Biology, McGill University, Montreal, Quebec, Canada.
Biochem Genet. 1988 Oct;26(9-10):631-44. doi: 10.1007/BF02399607.
The enzymatic basis for the differences in hepatic ganglioside patterns in the mouse strains C57Bl/6 and Swiss White (SW) was investigated. SW has a "Swiss-type" ganglioside profile, expressing GM1- and GD1a- in addition to GM2- as major hepatic gangliosides, whereas C57Bl/6 shows a "GM2-type" profile, expressing only GM2- as the major hepatic ganglioside. The enzyme UDP-galactose:GM2 ganglioside galactosyltransferase (GM2-GalT), which catalyzes the synthesis of GM1 ganglioside, showed a four- to fivefold elevation in intact and solubilized liver Golgi membrane fractions of the SW strain compared to C57Bl/6. Crosses between C57Bl/6 and SW produced an F1 generation with a hepatic ganglioside and enzymatic phenotype intermediate between those of the two parental strains. All three genotypic groups show two forms of the Golgi apparatus enzyme with isoelectric points of 6.5-6.8 and 8.3-9.0. The simplest mode of action of genes which control the enzymatic phenotype that would be consistent with these findings are one or two structural genes or one or two cis-regulatory genes affecting the rate of enzyme synthesis.
研究了小鼠品系C57Bl/6和瑞士白化小鼠（SW）肝脏神经节苷脂模式差异的酶学基础。SW具有“瑞士型”神经节苷脂谱，除了GM2-作为主要肝脏神经节苷脂外，还表达GM1-和GD1a-，而C57Bl/6显示“GM2型”谱，仅表达GM2-作为主要肝脏神经节苷脂。催化GM1神经节苷脂合成的UDP-半乳糖：GM2神经节苷脂半乳糖基转移酶（GM2-GalT）在SW品系完整和溶解的肝脏高尔基体膜部分中比C57Bl/6高出四到五倍。C57Bl/6和SW之间的杂交产生了F1代，其肝脏神经节苷脂和酶表型介于两个亲本品系之间。所有三个基因型组均显示高尔基体酶的两种形式，其等电点分别为6.5 - 6.8和8.3 - 9.0。与这些发现一致的控制酶表型的基因最简单作用模式是一个或两个结构基因或一个或两个影响酶合成速率的顺式调节基因。
