DISTRIBUTION AND IMMUNOCHEMICAL CHARACTERISTICS OF NEUROPEPTIDE-F (NPF) (MONIEZIA-EXPANSA)-IMMUNOREACTIVITY IN PROTEOCEPHALUS-POLLANICOLA (CESTODA, PROTEOCEPHALIDEA)

1. Using immunocytochemical techniques and confocal scanning laser mic roscopy, the proteocephalidean cestode, Proteocephalus pollanicola fro m Lough Neagh pollan (Coregonus autumnalis) was examined for the prese nce of the native platyhelminth neuropeptide, neuropeptide F (NPF). 2. An antiserum specific for whole-molecule NPF(1-39) (Moniezia expansa) did not immunostain nerve processes in P. pollanicola. A C-terminally -directed NPF(30-39) (M. expansa) antiserum immunostained nerve fibres and cell bodies of both the central and peripheral nervous systems, i ncluding innervation associated with the female reproductive system. 3 . The pattern of immunoreactivity was identical to that obtained using antisera to the C-terminal region of mammalian NPY-superfamily peptid es and the invertebrate neuropeptide, FMRFamide. 4. Under radioimmunoa ssay conditions, only the C-terminally-directed NPF antiserum cross-re acted with the P. pollanicola peptide and detected 58.74 ng/g wet weig ht of NPF-IR in extracts of the worm. 5. Chromatographic characterisat ion of P. pollanicola NPF-immunoreactivity indicated an apparent molec ular weight of 4400-4700 Da, similar to that of NPF (M. expansa). 6. F urther analytical HPLC characterisation identified two molecular forms of P. pollanicola NPF-immunoreactivity, both of which had different r etention times from those of NPF (M. expansa) and NPF (Artioposthia tr iangulata). 7. These data suggest that P. pollanicola possesses a neur opeptide which is homologous in its C-terminal region to NPF (M. expan sa) but differs in its mid- to N-terminal region.