The assembly of the developmentally arrested primordial follicle and the subsequent transition of the primordial follicle to the primary follicle are critical processes in normal ovarian physiology that remain to be elucidated. Ovarian follicles do not proliferate and the primordial follicles present in the neonate represent the total number of gametes available to a female throughout her repro...

A new species, Formica ribbeckei Radchenko & Perkovsky, sp. nov. , is described based on four workers from late Eocene Rovno amber (Ukraine). It most resembles F. flori Mayr, 1868 but differs the latter mainly by 5-segmented maxillary palps with preapical segment subequal in length to apical one, and shorter first funicular segment. Fossil luteola Presl, 1822, trigona macrognatha 1822 q...

Follicle rupture, the final step in ovulation, utilizes conserved molecular mechanisms including matrix metalloproteinases (Mmps), steroid signaling, and adrenergic signaling. It is still unknown how follicles become competent for follicle rupture/ovulation. Here, we identify a zinc-finger transcription factor Hindsight (Hnt) as the first transcription factor regulating follicle's competency fo...

We reviewed recent in vivo studies of the real-time changes in the vasculature of the follicle wall during selection of the dominant follicle as well as during ovulation in cows. Changes in follicle diameter and vascularity were determined by transrectal ultrasonography. Blood flow within the walls of the two largest follicles was detected at the time of wave emergence (largest follicle=5 mm in...

background: in vitro maturation (ivm) of immature oocytes collected from ovary has been proposed for fertility preservation. in addition, quality of oocytes post ivm is one of the factors determining its developmental competence. by using the non-invasive polscope system, both meiotic spindle (ms) and zona pellucida (zp) can be assessed in living oocytes. objective: the aim was to investigate t...

background: polycystic ovary syndrome (pcos) is a disorder in which there are numerous benign cysts that form on ovaries under a thick white covering that is one of the causes of infertility. follistatin is a single chain glycosylated polypeptide that can bind to activin. when follistatin binds to activin it suppresses the role of activin to stimulate the secretion of follicle stimulating hormo...

introduction: melatonin acts as an indirect antioxidant and is a powerful direct free radical scavenger and direct responses to melatonin in the gonads are detected. this study aims to investigate the influence of different doses of melatonin on preantral follicle development and oogenesis of in vitro cultured mouse ovarian follicles. materials and methods: preantral follicles with diameters of...

Here, we studied hair follicle development of Liaoning Cashmere goats. Every month for 1 year, skin samples were collected from five 1.5-year-old female goats, and made into paraffin sections. A number of parameters were measured of primary and secondary hair follicles via microscopic observation including follicle depth, hair bulb width, dermis and epidermis thickness, changes in follicle acti...

The ovarian follicle is a major site of steroidogenesis, crucially required for normal ovarian function and female reproduction. Our understanding of androgen synthesis and metabolism in the developing follicle has been limited by the sensitivity and specificity issues of previously used assays. Here we used liquid chromatography-tandem mass spectrometry to map the stage-dependent endogenous st...

In vitro ovarian follicle culture provides a tool to investigate folliculogenesis, and may one day provide women with fertility-preservation options. The application of tissue engineering principles to ovarian follicle maturation may enable the creation of controllable microenvironments that will coordinate the growth of the multiple cellular compartments within the follicle. Three-dimensional ...