RESUMO
The ovary of Sarcophaga lineatocollis is a typical polytrophic ovary. Each of its 25-30 ovarioles is composed of a small terminal filament, a small germarium and a vitellarium consisting of the egg follicle. The tunica propria is a noncellular, PAS-positive membrane. The ovarian follicle contains fifteen trophocytes and one oocyte. RNA is synthesized with the aid of the nuclei in the trophocyte cytoplasm, which are RNA- and PAS-positive. Protein is deposited intensively in the early stages of the trophocytes. The trophocytes of Sarcophaga lineatocollis synthesize RNA and protein more actively than the oocyte. In this fly, protein yolk precursor (PYP) bodies are supplied by the trophocyte cytoplasm to the ooplasm at an advanced stage of development. Nucleolar budding and vacuolation are observed in the trophocytes. RNA, DNA, protein and PYP bodies appear to be transported to the ooplasm from the trophocytes. Pyknotic trophocyte nuclei can be seen entering the ooplasm. The perinuclear Golgi bodies of the trophocytes help in the production and maturation of PYP bodies in the trophocytes before they are organized and passed on to the oocytes. Some RNA is contributed to the oocyte by the follicular epithelium. All these processes leading to maturation and development of the oocyte are discussed and interpreted.
Assuntos
Muscidae/citologia , Oócitos/análise , Animais , Feminino , Histocitoquímica , Oócitos/crescimento & desenvolvimentoAssuntos
Oócitos/crescimento & desenvolvimento , Ortópteros/anatomia & histologia , Animais , Células Epiteliais , Epitélio/anatomia & histologia , Feminino , Oócitos/citologia , Oócitos/ultraestrutura , Ortópteros/citologia , Folículo Ovariano/citologia , Ovário/anatomia & histologia , Oviductos/anatomia & histologia , Oviductos/citologiaRESUMO
The cortical zone of oocyte of Nandus nandus has been studied by cytological and histochemical techniques. In an early stage of oocyte development some granular substances appear in the juxtanuclear region which during oocyte growth move to the peripheral ooplasm and forms a thick cortical granular layer. Cytochemically, this cortical granular layer consists of proteins and carbohydrates along with RNA positive material, lipids, mitochondria and Golgi bodies. This cortical granular layer, later on, converts into the cortical vacuolar layer and ultimately forms the cortical alveolar structures in the vitellogenic oocyte of Nandus nandus. The results suggest that the cortical zone plays an important role in the storage of substances transported from the follicular epithelium to the oocyte. Further, the cortical granular substances which are rich in proteins, carbohydrates and lipoidal material, also help in the formation of jelly layers of the developing oocytes.
Assuntos
Oócitos/citologia , Óvulo/citologia , Animais , Metabolismo dos Carboidratos , Ciclo Celular , Proteínas do Ovo/metabolismo , Feminino , Peixes , Ácidos Nucleicos/metabolismo , Oócitos/metabolismo , Distribuição TecidualRESUMO
A cytochemical study of the cortical zone has been made in the early oocyte, during oogenesis and during pre- and post-vitellogenic stages of Gallus domesticus. The cortical zone of oocyte is not well-developed in the pre- and post-vitellogenic stages. Cytochemically, the cortical zone consists of proteins, carbohydrates, ribonucleic acid and lipids of L1, L2 and L3 types along with mitochondrial granules. A possible mechanism of transport of lipids and mitochondria from the follicular epithelium to the cortical ooplasm has been suggested.