OBJECTIVE To explore the effective isolation method for preantral follicles from human frozen-thawed ovarian tissue. METHODS The ovarian cortical tissue was frozen by direct cover vitrification (DCV). The frozen-thawed ovarian tissue was used for isolation of preantral follicles with collagenase combined with mechanical method and mechanical method alone, respectively. RESULTS 1. There was ...

Objective In the present study, the effects of alginate (ALG) concentration and ovarian cells (OCs) on the development and function of follicles were simultaneously evaluated. MaterialsAndMethods In the first step, preantral follicles (100-130 µm in diameter) were mechanically isolated from the ovaries of 2-week-old NMRI mice, encapsulated in the absence or presence of OCs in 0.5, 0.75 and 1% A...

BACKGROUND Neovascularization is necessary for follicular growth. Vascularization is first observed in preantral follicles, and thereafter the vasculature markedly increases in follicles undergoing development. Neovascularization includes angiogenesis and vasculogenesis. Vasculogenesis is the formation of new blood vessels by bone marrow-derived endothelial progenitor cells. It is unclear wheth...

Background: The majority of thousands of oocytes in the ovaries are small, non-growing and reside in preantral follicles (PFs). The development of a culture system for preantral follicle may be very useful for understanding the complex mechanism in folliculogenesis at early stages of development as wells as could offer a significant way for the propagation of livestock, including goats. This pa...

The effects of α-tocopherol and ternatin on the morphology, activation, and growth of goat preantral follicles in vitro cultured, for one or five days, were evaluated. Ovarian fragments were immediately fixed (non-cultured control) or in vitro cultured for one or five days in Minimum Essential Medium (MEM) with or without α-tocopherol or ternatin supplementation, both at concentrations of 5, 10...

Activins have been implicated as important regulating factors for many reproductive processes. The aim of this study was to determine the effect of activin A on the development of ovine preantral follicles in vitro. Mechanically isolated preantral follicles (161 +/- 2 microm) were cultured for 6 days in the presence of human recombinant activin A (0, 10 and 100 ng/ml). Half of the medium was re...

Developing a culture system for preantral follicles has important biotechnological implications due to the potential to produce a large number of oocytes for embryo production and transfer. To accomplish this goal, the present study was aimed to culture preantral follicles in the presence of different media, sera and FSH concentrations. Six-week-old preantral follicles (95 ± 5 µm) were cultured...

The developmental requirements of ovarian follicles are dependent on the maturation stage of the follicle; in particular, elegant studies with genetic models have indicated that FSH is required for antral, but not preantral, follicle growth and maturation. To elucidate further the role of FSH and other regulatory molecules in preantral follicle development, in vitro culture systems are needed. ...

The TGFβ superfamily comprises several bone morphogenetic proteins (BMP) capable of exerting gonadotropin-independent effects on the development of small preantral follicles. In embryonic tissues, BMP concentration gradients, partly formed by antagonistic factors, are essential for establishing phenotypic fate. By examining the expression of candidate genes whose protein products are known to i...

Although ovarian follicle growth is under the influence of many growth factors and hormones of which FSH remains one of the most prominent regulators. Therefore, factors affecting the sensitivity of ovarian follicles to FSH are also important for follicle growth. The aim of the present study was to investigate whether anti-Müllerian hormone (AMH) has an inhibitory effect on follicle growth by d...