1. The growth .energy of the granulosa cells in the ovarian follicles of normal guinea pig ovaries varies with the size of the follcle, and follows a definite growth curve. The growth energy in small follicles is relatively low, then a gradual rise takes place with increase in size of the follicle up to a maximum which is reached when the follicle attains medium size. This ascending part of the...

The mare, on the average, has an estrous period that lasts around 6.5 days. Most mares will ovulate follicles ranging between 40 and 45 mm, 24–48 h before the end of their standing heat. Therefore, mares can show strong signs of heat up to 48 h after ovulation. Although these parameters are well established for the average mare, follicle size at ovulation and the duration of estrus in mares var...

In a previous study, we showed that follicle size at weaning affects the response of a sow to a short-term altrenogest treatment after weaning. In this study, an attempt was made to prevent the growth of follicles into larger size categories before weaning by using different altrenogest treatments before weaning to improve reproductive performance after postweaning altrenogest treatments. Sows ...

Cows exhibiting estrus near fixed-time artificial insemination (AI) had greater pregnancy success than cows not showing estrus. The objective of this study was to determine the relationship between follicle size and peak estradiol concentration between cows that did or did not exhibit estrus during a fixed-time AI protocol. Ovulation was synchronized in beef cows by applying the CO-Synch protoc...

The granulosa follicle cell of the Graafian follicle of the rabbit ovary differentiates into a lutein cell involved in steroid synthesis. Cytological events which occur within the granulosa cell of the normally stimulated follicle prior to ovulation have been duplicated by the intrafollicular injection of exogenous gonadotrophin. The luteinization of the granulosa cells involves the accumulatio...

During Drosophila oogenesis, the formation of the egg respiratory appendages and the micropyle require the shaping of anterior and dorsal follicle cells. Prior to their morphogenesis, cells of the presumptive appendages are determined by integrating dorsal-ventral and anterior-posterior positional information provided by the epidermal growth factor receptor (EGFR) and Decapentaplegic (Dpp) path...

In the present paper, we develop an extensive theoretical analysis of the deterministic model for the control of ovulation in mammals proposed by Mariana et al., (1994), which is an extension of Lacker's model. Mariana et al. incorporated an age decaying factor in follicle maturity, and kept follicle growth law as Lacker first proposed. However, they produced only some numerical examples simula...

The mean areas of lymphoid follicles have been determined in 20 specimens of malignant follicular (centrocytic-centroblastic) lymphoma, 15 specimens of reactive follicular hyperplasia and 10 palatine tonsils. In all of the benign specimens and whenever possible for those showing malignancy, the areas of both the whole follicles (including the "mantle" zones) and of the follicle centres were mea...

In female mammals, primordial follicles consist of two types of cells, namely, oocytes and pregranulosa cells that surround the oocytes. The size of the primordial follicle pool determines the reproductive ability of female mammals. However, the underlying mechanisms controlling primordial follicle assembly remain unclear. In this study, we show that oocyte-derived Janus kinase (JAK) signaling ...

Primary ovarian insufficiency (POI) and polycystic ovarian syndrome are ovarian diseases causing infertility. Although there is no effective treatment for POI, therapies for polycystic ovarian syndrome include ovarian wedge resection or laser drilling to induce follicle growth. Underlying mechanisms for these disruptive procedures are unclear. Here, we explored the role of the conserved Hippo s...