Nuclear bodies in the egg cells of aGyrodactylus species (Platyhelminthes,Monogenea)

The presence and ultrastructure of distinctive nuclear bodies in a mature egg cell of aGyrodactylus sp. are described. These electron-dense granular bodies, which appear in section as open or closed rings or as a solid mass are not membrane-bound and lie in clusters close to the nucleolus. The nuclear bodies are compared with the nuclear-inclusion bodies previously reported in platyhelminths. The possible origin, significance and role of the nuclear bodies in thisGyrodactylus sp. are discussed.This paper is dedicated to Prof. J.C. Pearson, Department of Parasitology, The University of Queensland, on the occasion of his 65th birthdayThis study was supported by a Macquarie University Research Grant (to M.K.J) and by a Queen Elizabeth II Fellowship awarded by the Australian Research Council (to I.D.W.)