Towards identification of oesophageal gland proteins in Globodera rostochiensis

Secretory proteins from the dorsal and subventral oesophageal glands of potato cyst- nematodes (Globodera rostochiensis and G.pallida ) are considered to play an important role in the induction and exploitation of the specialized feeding cells (syncytia) that these parasites establish in the roots of their host plant. Identification of these secretory proteins will provide insight into the mechanisms involved in the formation of these syncytia, and is likely to aid in the development of novel forms of (artificial) host plant resistance to potato cyst-nematode infection. This thesis presents the data which were collected during a search for the oesophageal gland secretory proteins of G.rostochiensis.In the first part of the investigations (Chapters 2 to 5) the proteins of G.rostochiensis are examined using two-dimensional gel electrophoresis (2D-GE) followed by silver staining. Chapter 2 compares the protein patterns of two motile (2nd-stage juveniles (J2) and males) and two sedentary (4th-stage females and adult females) developmental stages using conventional (2D-GE) in large gels. This demonstrated very large differences in protein composition between these four developmental stages, and it was estimated that 74% of the polypeptides visible in these gels showed variations in their presence or abundance. The highest similarity index values were calculated for the protein patterns of both motile stages (0.674) and of both sedentary stages (0.767) with decreased values for all other pairwise comparisons.Chapter 3 introduces a miniature 2D-GE technique of which the high sensitivity is demonstrated by its ability to genotype single females of G. pallida . In Chapter 4 this mini 2D-GE technique is used to analyse the proteins of the complete range of post-embryonic developmental stages of G. rostochiensis. This analysis demonstrated large changes in protein pattern during the transformation of preparasitic J2 into sedentary J3 and during the metamorphosis of males into