SPERMIOGENESIS IN PHYTOPHAGOUS BUG (HEMIPTERA, PENTATOMIDAE) - AN ULTRASTRUCTURAL-STUDY

Ultrastructural and immunocytochemical studies were carried out on spe rmiogenesis in two species of phytophagous bug, Acrosternum aseadum an d Nezara viridula. The nucleus development involved changes in the sha pe and in the degree sf chromatin condensation, with specific aggregat ion patterns of DNA-histone complex occurring during this process. The acrosome showed a three-layered and the acrosomal content a paracryst alline arrangement. The axoneme presented a 9+9+2 microtubule pattern and bridges occurred between axonemal microtubules 1 and 5, and mitoch ondrial derivatives. Two paracrystalline structures embedded in amorph ous regions were observed in the mitochondrial derivatives. The use of the negative staining technique shows a zig-zag profile in the mitoch ondria due to infolding to the cristae, regularly spaced with approxim ately 40 nm. An electron dense rod was observed near the centriolar ad junct; it presented labelling for tubulin suggesting that this structu re may be involved in the microtubule organization during spermiogenes is of these insects.