Differential gene expression of beta-1,4-galactosyltransferases I, II and V during mouse brain development

Since most brain glycoproteins from beta -1,4-galactosyltransferase (beta - 1,4-GalT) I knockout mice were galactosylated without apparent reduction th e gene expression of novel beta1,4-GalTs II and V which are involved in N-l inked oligosaccharide biosynthesis in addition to beta -1,4-GalT I was stud ied during mouse brain development. Isolation and characterization of beta -1,4-GalT II and V cDNAs from mouse brains indicates that they are also fun ctioning in the brain. Northern blot analysis revealed that the beta -1,4-G alT I gene is expressed mainly in mid-embryonic stages, while the expressio n level of beta -1,4-GalT II transcript remains constant and of beta -1,4-G alT V transcript increases during mouse brain development after birth. In s itu hybridization revealed that beta -1,4-GalT II and V signals are present in most neural cells, with a marked difference between them in the hippoca mpus of adult mouse brain tissue. The differential gene expression of beta -1,4-GalTs I, II and V during mouse brain development could affect the diff erential galactosylation of brain glycoproteins, as revealed by lectin blot analysis.