Genetic Regulation of GM2 Expression in Liver of Mouse1 Yasuhiro HASHIMOTO, * Hideaki OTSUKA,* * Katsuko SUDO,***

GM2 containing NeuGc was found to be a major ganglioside in the liver of most inbred strains of mouse we have examined so far. They were DBA/2, C3H/He, C57BL/6, BALB/c, and CBA mice. However, WHT/Ht mouse does not contain a detectable amount of GM2 (NeuGc) but has GM3 containing NeuGc as the major ganglioside in the liver. The positive expression of GM2 (NeuGc) was demonstrated in the liver of Fx hybrids between WHT/Ht and DBA/2 mice, as one of the possible combinations. Moreover, the expression of GM2 (NeuGc) in the liver was proved to be an autosomal dominant trait by ganglioside analysis of 34 individual mice of the F2 and backcross generations. WHT/Ht mouse was demon-strated to be a recessive homozygote lacking GM2 (NeuGc) expression. During the analysis, interestingly enough, the enhanced elongation of the sugar chain in the gangliosides from GM2 (NeuGc) to GM1 (NeuGc) and GDI was observed in the liver of Fx mice and this elongation was segregated only in half members of F2 and backcross generations. In a series of studies on mammalian erythrocyte in the genetic regulation of the carbohydrate por