this manuscript reviews the present knowledge related to folliculogenesis in sheep.folliculogenesis starts with formation of primordial follicles before birth, present as a pool containing a certain number of follicles. by the attainment of puberty, a group of follicles from that pool starts to grow, a process known as primordial follicle activation or recruitment. the number of growing primord...

BACKGROUND A standard histomorphometric approach has been used for nearly 40 years that identifies atretic (e.g., dying) follicles by counting the number of pyknotic granulosa cells (GC) in the largest follicle cross-section. This method holds that if one pyknotic granulosa nucleus is seen in the largest cross section of a primary follicle, or three pyknotic cells are found in a larger follicle...

Mammalian females are born with a finite number of nonrenewing primordial follicles, the majority of which remain in a quiescent state for many years. Because of their nonrenewing nature, these "resting" oocytes are particularly vulnerable to xenobiotic insult, resulting in premature ovarian senescence and the formation of dysfunctional oocytes. In this study, we characterized the mechanisms of...

Activin A is a gonadal protein originally isolated from follicular fluid and is recognized as a local regulator of granulosa cell differentiation. Whether activin A promotes folliculogenesis, however, still remains unclarified. The present study was designed to elucidate the effect of activin A on follicular growth in in vitro follicle culture systems. Preantral follicles, 100-120 microm in dia...

Initiation of folliculogenesis through the induction of primordial follicle development in the ovary has an important role in determining the fertility and reproductive fitness of most mammalian species. The factors that control this critical process are largely unknown. The hypothesis tested in the current study was that kit-ligand/stem cell factor (KL) promotes the initiation and progression ...

This manuscript reviews the present knowledge related to folliculogenesis in sheep.Folliculogenesis starts with formation of primordial follicles before birth, present as a pool containing a certain number of follicles. By the attainment of puberty, a group of follicles from that pool starts to grow, a process known as primordial follicle activation or recruitment. The number of growing primord...

Background: The aim of the present study was to develop a three-dimensional (3D) collagen gel culture system for the in vitro growth and survival of buffalo preantral follicles with or without growth factors. Materials and Methods: Buffalo ovaries were collected from a local abattoir and preantral follicles were isolated through microdissection. Isolated preantral follicles were put either in c...

Follicle and oocyte growth is under the control of systemic gonadotropins and various local intraovarian factors. The present study was undertaken to examine the efficacy of peptide(s) isolated from ovine follicular fluid on preantral and antral follicles, oocytes, cumulus and granulosa cells, and oviductal epithelial cell growth in vitro in a heterologous species (Bubalus bubalis). Follicular ...