The model organism C. elegans is well studied; solid glycobiological literature have provided insights on the nematodal N-glycosylation machinery which shares many traits with other eukaryotic species. C. elegans is known to produce paucimannosidic proteins via a GnT-I-dependent route in which GnT-I firstly produces GlcNAc-capped glycoprotein intermediates. Further processing by two Hex isoenzymes (HEX-2 and HEX-3) encoded by two C. elegans genes (hex-2, hex-3) generate the unsubstituted C. elegans paucimannosidic glycans.
Other glycoenzymes catalise further processing and structural diversity including α-Man II and α1,6- and α1,3-fucosyltransferases. Albeit less active, a GnT-I-independent α1,6-fucosyltransferase has also been observed for C. elegans, indicating that both the GnT-I-dependent and -independent pathways may contribute to the formation of paucimannosidic N-glycoproteins in worms. However, the biosynthetic processes underpinning the unusual non-sugar and core-modified paucimannosidic N-glycans in C. elegans remain to be elucidated.