Submitted to: Society of Nematology Meeting
Publication Type: Abstract Only
Publication Acceptance Date: April 14, 1999
Publication Date: N/A
Nematode glycolipids have putative structural and bioregulatory roles; monoglycosylceramides (MGCs) consist of a single sugar residue attached to a long chain sphingoid base connected to a fatty acid molecule via an amide linkage. Our previous research demonstrated that MGCs comprised 0.17% (dry wt basis) of eggs of Meloidogyne incognita and mixed stages of Caenorhabditis elegans. In our current research, two attempts were made to isolate similar compounds from cysts of the soybean cyst nematode, Heterodera glycines. Cysts were extracted three times with hexane:isopropanol 3:2 (v:v). The crude lipid extract was fractionated on a silica column to obtain glycolipids, which were analyzed by two methods. First, fractions were analyzed on a reversed phase (octadecyl) HPLC column with a solvent of 1.0 % water in methanol. Second, the fraction containing putative MGCs was applied to a thin-layer chromatoplate developed with chloroform: 95% ethanol 70:30. Surprisingly, MGCs in cysts of Heterodera glycines were not detected with either method (threshold of detection = 0.005% of dry weight.) The results are interesting in view of the reported lack of lipase activity in hatching of eggs of other Heterodera species, in contrast to the lipase activity that reportedly accompanies root-knot nematode egg hatching.