A first step to elucidating the roles that steroids may play in the processes of ovarian development and early follicular growth is to identify the cell types that are likely to be receptive to steroids. Thus, cell types expressing receptors for oestrogen (alpha and beta form; ERalpha and ERbeta respectively), androgen (AR) and progesterone (PR) were determined by in situ hybridisation and immu...

Comparisons of numbers of antral ovarian follicles and corpora lutea (CL), of blood hormone concentrations, and of follicular fluid steroid concentrations and IGFBP activity were conducted between cows selected (twinner) and unselected (control) for twin births to elucidate genetic differences in the regulation of ovarian follicular development. Ovarian follicular development was synchronized a...

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...

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...

Ovaries, which provide a place for follicular development and oocyte maturation, are important organs in female mammals. Follicular development is complicated physiological progress mediated by various regulatory factors including microRNAs (miRNAs). To demonstrate the role of miRNAs in follicular development, this study analyzed the expression patterns of miRNAs in granulosa cells through inve...

Follicular development begins as early as the fourth month of fetal life [1]. At that time, the primordial germ cells (PGCs) have migrated from the yolk sac endoderm to the gonadal ridge, undergoing mitotic divisions. PGCs are called oogonia once they reach the gonads, then the oogonia enter the first meiotic division and become primary oocytes. Somatic cells originating from the primitive gona...

................................................................................................... 5 PUBLICATION LIST........................................................................................6 INTRODUCTION.............................................................................................7 1. THE MAMMALIAN OVARY...............................................................

1. Abstract 2. Introduction 3. Apoptosis during follicular development 3.1. Follicular development 3.2. Follicular atresia 4. Hormonal regulation of ovarian apotosis 4.1. Primordial follicles 4.2. Preantral follicles 4.3. Early antral follicles 4.4. Preovulatory follicles 4.5. Periovulatory follicles 5. Apoptosis in corpus luteum 6. Signal pathway of factors in regulating apoptosis in ovary 6.1...

The preantral-early antral follicle transition is the penultimate stage of follicular development in terms of gonadotropin dependence and follicle destiny (growth versus atresia). Follicular growth during this period is tightly regulated by oocyte-granulosa-theca cell interactions. Formation of the theca cell layer is a key event that occurs during this transitional stage. Granulosal factor(s) ...