SXP/RAL-2 proteins of the potato cyst nematode Globodera rostochiensis: secreted proteins of the hypodermis and amphids

A family of secreted proteins (thr: SXP/RAL-2 proteins) has been identified in animal parasitic nematodes and Caenorhabditis elegans. In this paper, we describe two full length cDNA sequences from the potato cyst nematode Globodera rostochiensis which could encode proteins similar to SXP/RAL-2 proteins. We show that although both genes are expressed in second stage juveniles and in sedentary females of G. rostochiensis. they have remarkably different spatial expression patterns. The mRNA derived from one of the genes (gr-sxp-l) was present in the hypodermis. as has been described previously for one of these: genes in an animal parasitic nematode. However, expression of the mRNA from the other gene was restricted to the: gland cells surrounding the amphidial sense organs (the sheath cells), In addition to providing the first description of SXP proteins from a plant parasitic nematode, this work provides the first detailed characterisation of a protein secreted from the amphids of a plant parasite.