Panagrellus redivivus: failure to find evidence for the occurrence and biosynthesis of sialic acids.

The occurrence of sialic acids in the free-living nematode Panagrellus redivivus was studied by periodate oxidation/3H]sodium borohydride reduction of about 10(7) nematodes. In parallel, the capability of sialic acid biosynthesis was examined by metabolic labeling of the same number of nematodes with N-3H]acetylmannosamine. In both experiments, radioactivity was incorporated into the nematodes. Mild acid hydrolysis, however, did not release radioactively labeled sialic acids or derivatives as tested by radio thin-layer chromatography, suggesting that P. redivivus does not contain or synthesize sialic acids.