Ultrastructural and cytochemical features of the supramedullary neurons of the pufferfish Diodon holacanthus (L.) (Osteichthyes).
Exceptionally high DNA contents were found in supramedullary neuron (SN) nuclei of the pufferfish Diodon holacanthus by quantitative microfluorimetric assay. This phenomenon has been explained by endoreplication, the functional significance of which is still unclear. In this view, the peptidergic nature and large dimensions make the teleostean clustered SN an interesting model for investigating the relationships between endoreplication, nuclear morphology and biosynthetic cellular activity. In this paper, we present a cytochemical and ultrastructural study on the SN of D. holacanthus (Tetraodontiformes). The nucleolar and nucleus structures suggest an intense production of ribosomal components in order to satisfy high cellular demands for protein synthesis. Accordingly, the cytoplasmic compartment presents an extensive rough endoplasmic reticulum, well-developed Golgi apparatus and a remarkable vesicular traffic. These features suggest that SN are engaged in an intense process of protein biosynthesis. The SN are completely surrounded by processes of different types of glial cells. The glial cells may be considered part of the SN cluster.
Cuoghi
B
B
Department of Animal Biology, University of Modena and Reggio Emilia, Italy. cuoghi.barbara@unimo.it
Marini
M
M
D000135:Acid Phosphatase / Q000032:analysis; D000818:Animals; D009474:Neurons / Q000737:chemistry / Q000166:cytology*; D013116:Spinal Cord / Q000737:chemistry / Q000166:cytology*; D023721:Tetraodontiformes
D000135:Acid Phosphatase