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The ultrastructure and immunogold labelling of pancreatic polypeptide-immunoreactive cells associated with the egg-forming apparatus of a monogenean parasite, Diclidophora merlangi

Published online by Cambridge University Press:  06 April 2009

D. W. Halton
Affiliation:
Comparative Neuroendocrinology Research Group, School of Biology and Biochemistry The Queen's University of Belfast, Belfast BT7 1NN, UK
G. P. Brennan
Affiliation:
Comparative Neuroendocrinology Research Group, School of Biology and Biochemistry The Queen's University of Belfast, Belfast BT7 1NN, UK
A. G. Maule
Affiliation:
Comparative Neuroendocrinology Research Group, School of Biology and Biochemistry The Queen's University of Belfast, Belfast BT7 1NN, UK
C. Shaw
Affiliation:
Department of Medicine, The Queen's University of Belfast, Belfast BT7 1NN, UK
C. F. Johnston
Affiliation:
Department of Medicine, The Queen's University of Belfast, Belfast BT7 1NN, UK
I. Fairweather
Affiliation:
Comparative Neuroendocrinology Research Group, School of Biology and Biochemistry The Queen's University of Belfast, Belfast BT7 1NN, UK

Extract

An electron microscopical examination has been made of the fine structure and disposition of pancreatic polypeptide immunoreactive cells associated with the egg-forming apparatus in Diclidophora merlangi. The cell bodies are positioned in the parenchyma surrounding the ootype and taper to axon-like processes that extend to the ootype wall. The terminal regions of these processes branch and anastomose and, in places, the swollen endings or varicosities form synaptic appositions with the muscle fibres in the ootype wall. The cells are characterized by an extensive GER-Golgi system that is involved in the assembly and packaging of dense-cored vesicles. The vesicles accumulate in the axons and terminal varicosities, and their contents were found to be immunoreactive with antisera raised to the C-terminal hexapeptide amide of pancreatic polypeptide. It is concluded that the cells are neurosecretory in appearance and that, functionally, their secretions may serve to regulate ootype motility and thereby help co-ordinate egg production in the worm.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1991

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