A 34 kDa vitellogenin protein in Heterodera schachtii is localised to second-stage juvenile seam cells that regulate cuticle development: Seam cells in Heterodera schachtii

Plant-parasitic nematodes (PPN) are economically important crop pests. Cyst nematodes undergo embryogenesis within the egg and arrest at the second-stage juvenile. Within the egg, the nematode is bathed in perivitelline fluid that contains the protein vitellogenin. In Caenorhabditis elegans, there are six encoding genes that make four protein subunits that produce two complexes which have roles in nematode development by transporting lipids, providing amino acids, influencing post-embryonic phenotypes, and providing some environmental protection against bacterial infection. Annexins are also a family of proteins also found in perivitelline fluid. Neither of these groups of proteins have been fully characterised in PPN. Using a panel of three antibodies (MAC-356, IACR-PC320 and UH-VitA) raised to proteins present in the perivitelline fluid of cyst nematodes (Globodera spp. and H. schachtii) we characterised them by Western blot analysis, immuno-localisation studies, MALDI-TOF and LC/MS. The monospecific polyclonal antibody IACR-PC320 to an annexin from vitelline fluid recognised a band at ~34 kDa in H. schachtii which was slightly larger, ~35 kDA, in G. pallida. The antibody UH-VitA raised to a short synthetic peptide (EQQLRSSGKWEFSLFNAEEREG) and identified as having 86% similarity to sequences of vitellogenins identified from the published genomes of Globodera pallida, G. rostochiensis and H. schachtii, was shown in immuno-localisation studies to be present in seam cells of H. schachtii. We discuss this result in the light of recent studies in C. elegans, which show that seam cells are important in the regulation and development of the cuticle surface coat.