Ultrastructure of ovarian follicular epithelium of the amazonian fish Pseudotylosurus microps (Gunther) (Teleostei, Belonidae): I. the follicular cells cycle of development

Abstract

ABSTRACT. The present paper deals with the changes on ultrastructural features of the follicular cells along the growth of the oocyte of PselidotyloslIrlis microps (Gunther, 1868). The epithelium pass from single squamous to pseudostratified and finally cylindric. Remarkable are the changes in the nuclear shapes, the increasing amount of rough endoplasmic reticulum and the formation of large lipid deposits in the follicular cells by the end ofvitellogenic phase. Very peculiar intercellular deposits forms between the perinucleolar and vitellogenic phase of oocyte maturation. A1-though largely referred to in the specialized literature, our attempts to correlate the follicular cells changes with the formation of the oocyte envelopes or even with an endocrine function are not supported by conclusive evidences in the present paper. KEY WORDS. PselidolyloslIrlis microps, follicular epithelium, ultrastructure, teleostThe ovarian follicular covering has been demonstrated to be a very important part during oocyte growth in a number of different classes ofanimals. The dynamic aspect of its structure along oogenesis largely suggests that specific functional interrelationships between follicle cells and oocyte may exist prior, during, and eventually after oocyte maturation. Among the fishes a number of functions have been attributed to the follicle cells, as in the production of the components of the

Structure and ultrastructure of oogenic stage in short mackerel Rastrelliger brachysoma (Teleostei: Scombidae)

“…However, only in ultrastructural study in teleost fish, it possible to investigate the details of gametogenic processing at cellular and organelles levels (GRIER, 2000). There have been many investigations of the oogenic ultrastructure in different ways including concerning the development of oogenic stage (ABASCAL and MEDINA, 2005), development of cytoplasmic organelles and follicular cells (CRUZ-LANDIM and CRUZ-HOFLING, 2001). Although, the Scombroid species is composed of several high commercial values for fisheries, it has rarely been selected for examination.…”