Systematic searches of the DNA sequence databases have revealed in C. elegans a series of predicted genes homologous to mammalian glycosyltransferases which, if enzymatically active, could confer glycosylation similar to mammals. We have detected GnT-I,
beta-3-GalT, C4-GnT and GnT-V by enzyme assay of C. elegans lysates. In whole animals, lectin binding repertoires consistent with mammalian-like glycosylation patterns have been observed histochemically(1). Mutations in
sqv-3, a
beta-4-galactosyltransferase homolog cause developmental defects in vulval formation and sperm-egg interaction(2). These observations make the nematode an attractive model organism for the study of glycobiology. We have focused on 2 C. elegans genes homologous to the mammalian glycosyltransferases GnT-V (
yk126h8) and C2-GnT (F44F4.6). We have obtained and sequenced these cDNAs. The predicted proteins are 59.9% similar, 36.7% identical for the GnT-V homolog
yk126h8 and 52.3% similar, 29.4% identical for the C2-GnT homolog F44F4.6. We created a frozen Tc1-insertion mutant bank and isolated Tc1 insertion lines for both homologues from which we are currently generating deletion alleles. In addition, the transcript 5! ends are being mapped, the gene-products are being tested for enzyme activity and the expression pattern during C. elegans development is being assessed using GFP reporter protein fusions to the genomic promoter regions in transgenic animals. (1) G Borgonie et al Histochem 101:379 (2) T Herman & B Horvitz ECWM 1996 #6