Oocyte growth, follicular complex formation and extracellular-matrix remodeling in ovarian maturation of the imperial zebra pleco fish Hypancistrus zebra

Abstract

This contribution describes the growth of oocytes, addressing the formation of structures that compose the follicular complex, as well as the remodeling of the extracellular matrix, specifically laminin, fibronectin and type IV collagen during gonadal maturation. Thirty-seven females of the Acari zebra fish, Hypancistrus zebra were captured and the ovaries were submitted to histological processing for light and electron microscopy and immunohistochemistry techniques. Oogonia and four stages (I – IV) of oocytes were distinguished, and structures such as the postovulatory follicle and atretic oocytes (initial and advanced atresia) were observed. The follicular complex consists of the mature oocyte, zona radiata (Zr1, Zr2 and Zr3), follicular cells, basement membrane and theca. During oocyte growth, proteins of the extracellular matrix showed different intensities of staining. Based on these observations, a model of oocyte growth is proposed to define specific characteristics of the oocyte and the remodeling of the extracellular matrix in the ovary of H. zebra. This model of oocyte growth can be extended to other species of ornamental fishes. This study contributes data for induced fertilization and eventual conservation of this species.

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Human Menstrual Blood-Derived Stromal Cells Promote Recovery of Premature Ovarian Insufficiency Via Regulating the ECM-Dependent FAK/AKT Signaling

“…The abnormity of these ECM molecules in quality or quantity will trigger structural or functional disturbance of target organs. In ovaries, germ cells maturation and follicles development rely much on the re-organization and modification of ECM to provide major collagen framework for ovarian tissue and serve as transportation hub for nutrients, hormones and signaling molecules [ 58 , 59 ]. As indicated in this study, the expression of COL6A5 and COL9A2 were down-regulated after CTX treatment, which signified the destructive effect of CTX on ovarian structure and function.…”

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