Ovarian follicle activation can be defined as primordial follicles in the ovary moving from a quiescent (inactive) to a growing phase. The primordial follicle in the oocyte is what makes up the pool of follicles that will be induced to enter growth and developmental changes that change them into pre-ovulatory follicles, ready to be released during ovulation. The process of development from a primordial follicle to a pre-ovulatory follicle is called folliculogenesis. Activation of the primordial follicle involves the following: a morphological change from flattened to cuboidal granulosa cells, proliferation of granulosa cells, formation of the protective zona pellucida layer, and growth of the oocyte. It is widely understood that androgens act primarily on preantral follicles and that this activity is important for preantral follicle growth. Additionally, it is thought that androgens are involved in primordial follicle activation. However, the influence of androgens on primordial follicle ...
This study was designed to develop preantral follicle isolation and classification protocols for the domestic dog as a model for endangered canids. Ovary donors were grouped by age, size, breed purity, ovary weight and ovary status. Ovaries were randomly assigned to 1 of 3 digestion protocols: A) digestion and follicle isolation on the day of spaying; B) storage at 4 degrees C for 18 to 24 h prior to digestion and follicle isolation; C) digestion on the day of spaying, then incubation at 4 degrees C for 18 h prior to follicle isolation. Minced tissue was placed in a collagenase/DNase solution at 37 degrees C for 1 h. Follicles were classified by oocyte size and opaqueness and by size and appearance of the granulosa cell layers. Preantral follicles contained small, pale oocytes. Preantral follicles containing grown oocytes with dense cytoplasmic lipid were designated as advanced preantral. Only advanced preantral and early antral follicles were examined and classified further. Group 1 follicles had
TY - JOUR. T1 - Markers of growth and development in primate primordial follicles are preserved after slow cryopreservation. AU - Jin, Shiying. AU - Lei, Lei. AU - Shea, Lonnie D.. AU - Zelinski, Mary B.. AU - Stouffer, Richard L.. AU - Woodruff, Teresa K.. N1 - Funding Information: Supported by Oncofertility Consortium: National Institutes of Health grants RL1-HD058295 and PL1EB008542 and Training for a New Interdisciplinary Research Workforce (T90) grants 1TL1CA133837 , U54-HD18185 , and NCRR RR00163 . PY - 2010/5/15. Y1 - 2010/5/15. N2 - Objective: To investigate the effect of slow cryopreservation on the morphology and function of primate primordial follicles within ovarian tissue slices. Design: Fresh monkey ovarian tissue was frozen by slow cryopreservation and thawed for analysis of morphologic and functional parameters. Setting: University-affiliated laboratory. Animals: Rhesus monkey ovarian tissue. Intervention(s): None. Main Outcome Measure(s): Histologic analysis, follicle counting, ...
The objective of this study was to investigate the effect of equine chorionic gonadotropin (eCG) on ovarian follicles at three stages of development (emergence, dominance and early static phases) during the first follicular wave (FFW) in Holstein heifers. Heifers (n=20) were randomly assigned into four experimental groups (n=5 in each group). Heifers received eCG (500 IU; Folligon®; Intervet, Holland; i.m) a) on the day of follicle emergence (day of ovulation; group 1), b) on the dominant phase (dominant follicle (DF): the first day in which follicle was observed at ≥10 mm; group 2, and c) on the early static phase (group 3) of the FFW. Control group heifers did not receive any treatment. Daily ultrasonography was conducted to monitor ovarian structure throughout estrous cycle. All treatment group heifers, regardless of the stage of follicle development, displayed follicle growth after eCG injection. Administration of eCG, in group 1, hastened DF detection and induced co-dominant follicles; whereas,
Calorie restriction inhibits ovarian follicle development and follicle loss through activating SIRT1 signaling in mice. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
Ovarian follicle selection is an important process impacting the laying performance and fecundity of hens, and is regulated by follicle-stimulating hormone (FSH) through binding to its receptor [follicle-stimulating hormone receptor (FSHR)]. In laying hens, the small yellow follicle (6-8 mm in diameter) with the highest expression of FSHR will be recruited into the preovulatory hierarchy during ovarian follicle development. The study of molecular mechanism of chicken follicle selection is helpful for the identification of genes underlying egg-laying traits in chicken and other poultry species. Herein, the transcriptomes of chicken small yellow follicles differing in the mRNA expression of FSHR were compared, and a total of 17,993 genes were identified in 3 pairs of small yellow follicles. The Wnt signaling pathway was significantly enriched in the follicles with the greatest fold change in FSHR expression. In this pathway, the expression level of Wnt4 mRNA was significantly upregulated with a log2(fold
Chronic exposure to the polycyclic aromatic hydrocarbon 7,12-dimethylbenz[a]anthracene (DMBA), generated during combustion of organic matter including cigarette smoke, depletes all ovarian follicle types in the mouse and rat, and in vitro models mimic this effect. To investigate the mechanisms involved in follicular depletion during acute DMBA exposure, two concentrations of DMBA at which follicle depletion has (75 nM) and has not (12.5 nM) been observed were investigated. Postnatal day four F344 rat ovaries were maintained in culture for four days before a single exposure to vehicle control (1% DMSO; CT) or DMBA (12 nM; low-concentration or 75 nM; high-concentration). After four or eight additional days of culture, DMBA-induced follicle depletion was evaluated via follicle enumeration. Relative to control, DMBA did not affect follicle numbers after 4 days of exposure, but induced large primary follicle loss at both concentrations after 8 days; while, the low-concentration DMBA also caused ...
Although the process is similar in many animals, this article will deal exclusively with human folliculogenesis. In biology, folliculogenesis is the maturation of the ovarian follicle, a densely packed shell of somatic cells that contains an immature oocyte. Folliculogenesis describes the progression of a number of small primordial follicles into large preovulatory follicles that occurs in part during the menstrual cycle. Contrary to male spermatogenesis, which can last indefinitely, folliculogenesis ends when the remaining follicles in the ovaries are incapable of responding to the hormonal cues that previously recruited some follicles to mature. This depletion in follicle supply signals the beginning of menopause. The primary role of the follicle is oocyte support. From birth, the ovaries of the human female contain a number of immature, primordial follicles. These follicles each contain a similarly immature primary oocyte. At puberty clutches of follicles begin folliculogenesis, entering a ...
STUDY QUESTION: Is it possible to identify by mass spectrometry a wider range of proteins and key proteins involved in folliculogenesis and oocyte growth and development by studying follicular fluid (FF) from human small antral follicles (hSAF)?. SUMMARY ANSWER: The largest number of proteins currently reported in human FF was identified in this study analysing hSAF where several proteins showed a strong relationship with follicular developmental processes.. WHAT IS KNOWN ALREADY: Protein composition of human ovarian FF constitutes the microenvironment for oocyte development. Previous proteomics studies have analysed fluids from pre-ovulatory follicles, where large numbers of plasma constituents are transferred through the follicular basal membrane. This attenuates the detection of low abundant proteins, however, the basal membrane of small antral follicles is less permeable, making it possible to detect a large number of proteins, and thereby offering further insights in ...
Ovarian stimulation is an important phase of in vitro fertilization (IVF) treatments. The harvest of a larger number of viable eggs per cycle compensate eventual laboratory difficulties and allow for the selection of embryos with higher implantation potential. In the current protocols, based on the most prevailing theory of ovarian follicular development, stimulation drugs are usually started on the second or third day after the beginning of menses. The follicular phase of the menstrual cycle is believed to be the only favorable moment for follicular development.. In the early 2000s a new model of human ovarian follicular development (follicular waves) has been proposed based on frequent transvaginal ultrasound observations between two ovulations. It has been shown that ovarian antral follicles develop in synchronous groups, two to three times in a cycle. In fact the follicular wave phenomenon has been initially described in the 80s on domestic animals, like the mare and the cow. Moreover, ...
The GnRH-induced ovulation of small dominant follicles was associated with reduced pregnancy rates and late embryonic/fetal survival around the time of embryo-uterine attachment. PAGs are secreted by binucleated trophoblast cells into the maternal circulation and have been used to monitor placental function and embryo/fetal mortality. The overall objective was to examine the relationship between ovulatory follicle size and circulating concentrations of bPAG. Postpartum cows were treated with the CO-Synch protocol and timed artificial insemination and classified into one of four groups based on the size of the follicle induced to ovulate at GnRH-2. There was an effect of treatment on pregnancy rates at d 30 post insemination with pregnancy rate being higher following GnRH-induced ovulation of 14 to 15 mm compared to 12 to 13 mm follicles. The first increase in bPAG occurred on d 24. There was an effect of day on bPAG but no effect of ovulatory follicle size or ovulatory follicle size by day ...
Factors that cause some primordial follicles to enter the growth phase while the others remain quiescent are unknown. The hypothesis was tested that primate primordial follicles can survive and initiate growth in vitro in serum-free medium. Superficial pieces of ovarian cortex, containing mostly primordial follicles, were obtained from baboon fetuses during late gestation and cultured for 0, 2, 4, 7, 10 or 20 days in Waymouth MB 752/1 medium supplemented with insulin, transferrin, selenium, linoleic acid, and bovine serum albumin (ITS +). Histological examination of cortical pieces revealed that after 2 and 4 days in culture, the total number of primordial follicles had decreased by 55 and 76% (P | 0.01) respectively, relative to day 0 of culture. This was associated with a sustained, 5- to 8-fold increase in total primary follicles (P | 0.01) beginning on day 2 of culture. There was also a gradual increase in the total number of early secondary and secondary follicles. The average
Transforming growth factor-β (TGF-β) superfamily is a group of about 35 proteins involved in pre- and postnatal physiological processes.56 Members of this superfamily are expressed by oocytes and ovarian somatic cells in key developmental stages.57, 58, 59, 60, 61 Throughout life ovarian follicles leave the resting pool to join the growing pool. The precise mechanism of follicular recruitment is not fully elucidated, however, members of the TGF-β family are involved in the process. Bone morphogenetic proteins (BMP) 7 and 4 promote primordial to primary follicle transition.62 Similarly, anti-Mullerian hormone (AMH), another member of the TGF-β superfamily, is involved in initiation of primordial follicle growth.63 Progression of primary follicles to early antral stage is enhanced by growth and differentiation factor-9 (GDF-9) and BMP-15 of oocyte origin, activins of granulosa origin, and BMP-4 and BMP-7 of thecal origin.61 Antral follicle growth and follicle selection mechanism involves the ...
Women are born with a finite population of ovarian follicles, which are slowly depleted during their reproductive years until reproductive failure (menopause) occurs. The rate of loss of primordial follicles is determined by genetic and environmental influences, but certain toxic exposures can accelerate this process. Ionizing radiation reduces preantral follicle numbers in rodents and humans in a dose-dependent manner. Cigarette smoking is linked to menopause occurring 1-4 yr earlier than with nonsmokers, and components of smoke, polycyclic aromatic hydrocarbons, can cause follicle depletion in rodents or in ovaries in vitro. Chemotherapeutic agents, such as alkylating drugs and cisplatin, also cause loss of preantral ovarian follicles. Effects depend on dose, type, and reactivity of the drug, and the age of the individual. Evidence suggests DNA damage may underlie follicle loss induced by one common alkylating drug, cyclophosphamide. Occupational exposures have also been linked to ovarian damage. In
Several lines of evidence indicate that retinoids, derivates of vitamin A, affect reproductive function in birds, however, the mechanism of their action in the ovary is still unknown. Therefore, the present study was designed (i) to show whether in the domestic hen 9-cis retinoic acid (9-cis RA), one of the retinoids, influences steroid secretion in vitro by white and yellow chicken ovarian follicles, and (ii) to detect expression of retinoic acid RXR receptor mRNA in these follicles. The white follicles (small: 1-4 mm, medium: 4-6 mm and large 6-8 mm in diameter) and the three largest yellow preovulatory follicles (F3-F1; 25-37 mm) were isolated from the ovary 3 h before ovulation. The granulosa layer was separated from the theca layer in the preovulatory follicles, which were subsequently divided into 4 equal pieces. The isolated whole white follicles or parts of the granulosa or theca layers were incubated for 24 h at 38oC in Eagle's medium in the following 4 groups: control, ovine LH ...
Evaluation of antral follicle growth in the macaque ovary during the menstrual cycle and controlled ovarian stimulation by high-resolution ultrasonography
New evidence from 3-D culture of a variety of cell types have produced intriguing results, emphasizing the importance of a 3-D perspective when developing new culture systems [20]. This may be especially critical for follicle culture due to the complex nature of the interactions between the oocyte and the granulosa/thecal cells, the necessity of preserving communication through gap junctions and the length of time needed in culture for immature oocyte maturation. This report describes the first application of a new and unique hyaluronan- based hydrogel to the 3-D culture of ovarian follicles. Follicle architecture was maintained and diffusion through the gel during IVC was sufficient to support follicle growth, resumption of meiosis and oocyte nuclear and cytoplasmic maturation. Further modifications to follicle growth pattern were attempted by the addition of extracellular matrix components to the HA gel. This new model for 3-D in vitro follicle maturation was also successfully applied to ...
Thrilled to be 6 weeks pregnant. Nevertheless, its always recommended for you to choose a fluffy pillow to provde the most consolation during your sleep period. You also may low antral follicle count and pregnancy symptoms and truly mistake a counf for something like normal pregnancy. This calculates the anticipated due date from the first day of the last regular menstrual period (LMP or Low antral follicle count and pregnancy no matter components known to qntral this inaccurate, reminiscent of a shorter 7 weeks pregnant and showing second pregnancy longer menstrual cycle ahtral. While there is no single sex place that is finest for babymaking (or for selecting your babys sex), stick to one the place youll be in your again when antal is over. It is obtainable in the form of a juice, an pregnancg used in colonic irrigation, or capsules. So watch for a couple of weeks after which take a low antral follicle count and pregnancy oow look at once more or make another go to to your physician. A ...
The results of this study demonstrated that there is a remarkable difference in in vitro-growth of primary follicles retrieved from neonatal mice of different ages, which suggests a positive correlation between number of retrieved follicles and derivation of mature oocytes per animal. Continuous increase in retrieval number of preantral follicles was observed as the age was increased up to 14-day-old and, among those follicles, primary follicles yielded developmentally-competent oocytes following our in vitro-culture. The best efficiencies in follicle retrieval and oocyte maturation was obtained at 11 day old females and percentile values of intrafollicular oocytes to initiate and complete meiotic maturation, however, are similar among the ages (9- to 11-day-olds).. Although many efforts for the establishment of in vitro culture system for primary follicles have been made (Eppig et al., 1989; Cortvrindt et al., 1996; OBrien et al., 2003; Lenie et al., 2004; Sadeu et al., 2008), there was no a ...
Introduction: It has been documented that mammalian ovaries receive sympathetic, parasympathetic and sensory nerve fibers. The aim of this work was to investigate the effects of sensory denervation with capsaicin at the first vaginal opening (FVO) on follicular development and the expression of TRPV1 receptors in ovary cells as well as in the dorsal root ganglia (DRGs) and lumbar dorsal spinal cord neurons of guinea pigs. The DRGs and lumbar dorsal spinal cord neurons serve as a nerve connection from the ovaries to the CNS. Materials and Methods: Female guinea pigs received a subcutaneous injection of capsaicin (30 mM) at 10 days of age (P10), while control animals were injected with vehicle. Using light microscopy, we counted healthy preantral follicles (HPF), healthy antral follicles (HAF), atretic preantral follicles (APF), and atretic antral follicles (AAF) in the ovaries at the FVO, and the numbers of TRPV1-positive cells were counted in the ovarian follicles, DRGs, and lumbar dorsal spinal cord
In adult sheep, inhibin expression in developing follicles appears to be associated with antrum formation. Our objective was to investigate using in situ hybridization and immunohistochemistry whether antral follicles present before birth in the sheep expressed mRNA or peptide for inhibin α- and βA-subunits. At days 70 and 100 when only primordial and primary follicles were present, there was no detectable mRNA or peptide for either inhibin subunit. By days 130 and 140 (term = 145 days), many secondary follicles were present, a proportion of which (∼50%) expressed detectable levels of α-subunit mRNA but not peptide. A number of antral follicles were present by this stage, all of which expressed α-subunit mRNA and peptide. Expression of βA-subunit mRNA and peptide was undetectable at all stages of gestation. Our results indicate that even in non-ovulatory follicles present before birth, expression of inhibin, at least the α-subunit, is developmentally linked with antrum formation ...
The objective of this study was to examine the effect of an excess intake of quickly degradable nitrogen (QDN) on ovarian follicle development. Twenty lactating dairy cows were fed mixed silage and concentrates twice daily. The control diet was a typical ration for high producing dairy cows in the United Kingdom (crude protein (CP)=17.5%; metabolizable energy (ME)=11.8 MJ/kg DM). The cows were randomly divided into two groups, control diet (control; n=10) and excess QDN diet (QDN; n=10). The QDN group was fed an additional 250 g of urea per cow per day; for 17 days. Ovaries were scanned daily using B-mode ultrasonography for 17 days. The excess QDN diet resulted in significantly elevated (P|0.05) plasma urea concentrations four days after starting urea feeding and these were maintained until the end of the experiment. The QDN treatment did not significantly affect (P|0.5) the number of small (≥0.5 cm diameter), medium to large follicles (0.5-1.4 cm diameter) and pre-ovulatory (1.5-2.3 cm diameter)
Ovarian follicle is a fluid filled structure that consists of the developing oocyte as well as other cells involved in the menstuation process -Every month one of these primary follices containing a primary oocyte will devleop into a secondary follicle that contains a secondary oocyte. -During stimulation, secondary oocyte is released into the fallopian tubes while the remainder of cells develop into the corpus luteum.. -Other than the oocyte itself, there are two types of cells in the ovarian follicle:. (1) Theca Cell: Regulates Oogenesis and produces sex steroid hormones. (2) Granulosa Cell: FSH stimulates granulosa cells to convert androgens (coming from the thecal cells) to estradiol by aromatase during the follicular phase of the menstrual cycle.. General Process: LH acts on -, Theca cell = Cholesterol -, Androgen -, Travels to Granulosa cell; which with the aid of FSH; Androgen -, Oestrogen.. ...
Storage conditions during transportation of explanted ovaries are a critical step in setting up fertility preservation protocols in both animal and human fields. Here, we evaluated the effects of ovary storage at 4 °C on the preservation of preantral follicles and oocytes retrieved from antral follicles using the domestic cat as model. Ovaries were harvested from fifty-five healthy domestic queens during ovariectomy and stored at 4 °C for 0 (control), 24, 48, 72 and 96 h. In Experiment 1, the effects of the storage period at 4 °C on the morphology, cytoskeleton (α/β tubulin) and DNA integrity (phosphorylation of histone H2AX) of preantral follicles were investigated. In Experiment 2, oocytes recovered from antral follicles were matured and fertilized in vitro to evaluate their meiotic and developmental competence. Reactive oxygen species (ROS), glutathione (GSH) and lipid peroxidation were measured in matured oocytes. The results showed that: a) storage up to 24 h did not affect the morphology and
rhFSH and rhActA have been used in mammalian ovarian follicle culture systems for activation of follicular growth in vitro and suggested to be responsible for primordial follicle survival through MAPK and Akt pathways. The aim of our study was to determine the effects of rhFSH and rhActA on Akt, pAkt, MAPK1/3 and pMAPK1/3 protein levels in bovine ovarian cortical strips cultured in vitro. Ovarian cortical strips from heifers were cultured in the presence of rhFSH (50 ng/mL), rhActA (100 ng/mL) or combination of these factors for 6 days. The strips were embedded in paraffin for histological observations and homogenized for western blot to determine Akt, pAkt, MAPK1/3 and pMAPK1/3 protein levels after the culture. Determination of primordial, primary and secondary follicle proportions at the end of culture as well as comparison of healthy follicle for each developmental stage after the culture was performed to quantify follicle survival and activation. pAkt protein levels were significantly lower in rhFSH
Oocytes are generally recovered as a cumulus-oocyte complex, an oocyte surrounded by the cumulus cells that nourish it, dislodged from the follicle wall. Initially as a follicle grows, the cumulus cells are tightly adhered to the follicle wall and the mass of cells itself is very dense; the cells are very close together. As the follicle grows and becomes a dominant follicle the cumulus mass starts to expand as the cells secrete an extracellular matrix that spreads them apart. Nearing ovulation this expansion makes the attachment to the follicle wall weaker and weaker so that during ovulation the oocyte can be swept from the follicle into the oviduct. The loosening of the attachment makes the oocyte somewhat easier to recover nearing ovulation, although as the follicle enlarges it is more difficult to create the turbulence necessary to dislodge the oocyte. For these reasons, aspiration of the immature follicles with their firmly attached cumulus-oocyte complex, tend to have the highest recovery ...
Oocytes are generally recovered as a cumulus-oocyte complex, an oocyte surrounded by the cumulus cells that nourish it, dislodged from the follicle wall. Initially as a follicle grows, the cumulus cells are tightly adhered to the follicle wall and the mass of cells itself is very dense; the cells are very close together. As the follicle grows and becomes a dominant follicle the cumulus mass starts to expand as the cells secrete an extracellular matrix that spreads them apart. Nearing ovulation this expansion makes the attachment to the follicle wall weaker and weaker so that during ovulation the oocyte can be swept from the follicle into the oviduct. The loosening of the attachment makes the oocyte somewhat easier to recover nearing ovulation, although as the follicle enlarges it is more difficult to create the turbulence necessary to dislodge the oocyte. For these reasons, aspiration of the immature follicles with their firmly attached cumulus-oocyte complex, tend to have the highest recovery ...
The goals of this research proposal are to further our understanding of the reproductive aging process in women and to improve our ability to clinically assess and model reproductive aging. Reproductive aging is a continuous process that begins many years prior to menopause. Women in their late 30s and early 40s usually maintain normal menstrual function and ovulatory status, yet fertility in these women is considerably compromised compared to younger women. The primary mechanism of reproductive aging is through the process of ovarian primordial follicle (egg) depletion, a process that exhibits considerable variation between women. As a result, the age at which an individual begins to experience infertility and menstrual cycle changes secondary to follicle depletion also varies significantly and is difficult to predict. The clinical assessment of the number of primordial follicles remaining in the ovary has traditionally relied upon the measurement of ovarian or pituitary hormones such as FSH, ...
Light microscopy of a growing ovarian follicle at the early antral stage of development. The central oocyte (female germ cell) is surrounded by follicular cells separated from the oocyte cytoplasm by a thin coat of special proteins called the zona pellucida which serves to bind sperm during fertilization, and to protect the early embryo if formed. Peripheral layers of flattened cells make up the thecal tissues. Fluid-filled gaps between follicular cells signify the initial stages of antrum formation during folliculogenesis which enlarge to dominate the volume of the follicle as it approaches ovulation. Magnification x500 when printed at 10 cm. - Stock Image C023/9426
After ovulation in mammals, rupture of mature follicles is reorganized into the corpus luteum that secrets progesterone (P4) to stimulate endometrial development. The situation in birds differs considerably. Beyond ovulation the ruptured avian follicle forms a postovulatory follicle (POF) that is not considered analogous to mammalian corpus luteum. The function and regression mechanisms of avian POFs remain poorly understood. Here we investigated the changes in apoptotic and autophagic activities that were involved during POF degradation. Results showed that the structure and secretory function of POF3 manifested the most apparent deterioration during whole processes of regression. A TUENL assay revealed that the granulosa layer maintained longer viability than the theca layer. Importantly, mitochondrial apoptosis and endoplasmic reticulum (ER) stress-associated genes and proteins reached their highest levels in the granulosa cells of POF3. Beclin1 was distributed mainly in theca cells and
After ovulation in mammals, rupture of mature follicles is reorganized into the corpus luteum that secrets progesterone (P4) to stimulate endometrial development. The situation in birds differs considerably. Beyond ovulation the ruptured avian follicle forms a postovulatory follicle (POF) that is not considered analogous to mammalian corpus luteum. The function and regression mechanisms of avian POFs remain poorly understood. Here we investigated the changes in apoptotic and autophagic activities that were involved during POF degradation. Results showed that the structure and secretory function of POF3 manifested the most apparent deterioration during whole processes of regression. A TUENL assay revealed that the granulosa layer maintained longer viability than the theca layer. Importantly, mitochondrial apoptosis and endoplasmic reticulum (ER) stress-associated genes and proteins reached their highest levels in the granulosa cells of POF3. Beclin1 was distributed mainly in theca cells and
Primordial follicles are found just under the tunica albuginea. They are one cell thick layer of somatic cells wrapping one oocyte, which is arrested in prophase I. Somatic cells area rather flattened to cuboidal, in close apposition to the oocyte. The follicle is separated from the surrounding stroma by a basal lamina. Those follicles that start growing also begin to mature, and will eventually release the fully developed ovum during ovulation, at the end of this maturing process. Depending on the author and the developing stage, follicles receive different names. Primary follicles show an increase in the oocyte size and the follicle somatic cells covering the oocyte change from flattened to cuboidal shapes. Furthermore, the pellucida membrane starts to be visible between the oocyte and the somatic cells of the follicle. As maturation progresses, follicle somatic cells proliferate and reorganize into several layers, altogether known as granulosa cells. Granulosa cells are enclosed by the ...
Objectives were twofold: 1 ) to determine the chronology of development of dominant ovarian follicles during the peripubertal period in heifers and 2) to determine whether feeding a diet with low energy content that delays onset of puberty alters chronology of dominant ovarian follicular development in peripubertal heifers. Ten heifers of composite breeding ( 1/4 Angus, 1/4 Hereford, 1/4 Red Poll, 1/4 Pinzgauer) were randomly assigned, at 8 mo of age, to receive a diet designed to produce 0.9 (n = 5) or 0.3 (n = 5) kg body weight gain per day for the duration of the experiment. To characterize changes in size of ovarian follicles, real-time linear ultrasonography of ovaries was conducted in all heifers every other day until puberty occurred. Blood samples were collected weekly to determine concentrations of progesterone and 17β-estradiol. Determination of time of puberty was based on increased concentrations of progesterone, ultrasound depiction of ovulation, and subsequent presence of a corpus luteum.
Question - Had U/S follicle size 31mm. Took clomid. What size a biggest follicle can be?. Ask a Doctor about when and why Ultrasound is advised, Ask an OBGYN, Gynecologic Oncology
I prefer to end my week either on a high note or hell, why not just high.. However, since Im now a responsible adult with a child, Ill be selecting the high note.. There are several tests out there to help physicians determine a womans Ovarian Reserve (cache of eggs). We have the AFC: Antral Follicle Count - Presumably, the number of antral follicles visible on ultrasound is indicative of the relative number of microscopic (and sound asleep) primordial follicles remaining in the ovary. Each primordial follicle contains an immature egg that can potentially develop in the future. In other words, when there are only a few antral follicles visible, there are less eggs remaining as compared to when there are more antral follicles visible. As women age, they have less eggs (primordial follicles) remaining, therefore they have less antral follicles visible on ultrasound. (1). We have the CD3 FSH:. Day 3 Follicle Stimulating Hormone - By measuring a baseline FSH on day 3 of the cycle (we do it on ...
Primary Follicle Definition - A primary follicle is an immature follicle in the ovary consisting of an egg (oocyte) surrounded by a single layer of...
Video articles in JoVE about ovarian follicle include A Method for Ovarian Follicle Encapsulation and Culture in a Proteolytically Degradable 3 Dimensional System, Methods for Imaging Intracellular pH of the Follicle Stem Cell Lineage in Live Drosophila Ovarian Tissue, Culture and Co-Culture of Mouse Ovaries and Ovarian Follicles, In Vitro Growth of Mouse Preantral Follicles Under Simulated Microgravity, Studying Mitochondrial Structure and Function in Drosophila Ovaries, Analysis of Chromosome Segregation, Histone Acetylation, and Spindle Morphology in Horse Oocytes, Three-dimensional Reconstruction of the Vascular Architecture of the Passive CLARITY-cleared Mouse Ovary, A Method to Study the Impact of Chemically-induced Ovarian Failure on Exercise Capacity and Cardiac Adaptation in Mice, Assessment of Ovarian Cancer Spheroid Attachment and Invasion of Mesothelial Cells in Real Time, Alginate Hydrogels for Three-Dimensional Organ Culture of Ovaries and Oviducts, Orthotopic Ovarian
This study aimed to investigate the developmental competence of ovum pick-up collected oocytes on three stages of the follicular wave: Days 2, 5 and 8. A group of 11 cows was used in successive cycles to perform ovum pick-up on either Day 2, 5 or 8 of an induced follicular wave (three sessions per stage). Follicular waves were initiated by puncturing the dominant follicle and all other follicles sized , or = 5 mm at Days 5-7 of the cycle. The plasma progesterone concentrations did not differ between the days of ovum pick-up: 4.0 +/- 1.8, 5.1 +/- 1.6 and 5.2 +/- 1.7 ng/ml for Days 2, 5 and 8, respectively. The proportion of oocytes with three or more layers of non-expanded cumulus cells was higher for Day 5 than Day 8, while Days 2 and 5 did not significantly differ from each other (85, 96 and 68% of 113, 60 and 101 oocytes for Days 2, 5 and 8, respectively). The proportion of oocytes competent to develop a blastocyst in an in vitro production system was higher for Days 2 and 5 than for Day 8: ...
Autotransplantation of cryopreserved ovarian cortex can be associated with a risk of cancer cell reseeding. This issue could be eliminated by grafting isolated preantral follicles. Collagenase NB6 is an enzyme produced under good manufacturing practices (GMP) in compliance with requirements for tissue engineering and transplantation in humans and thus can be used to isolate preantral follicles from ovarian tissue in the framework of further clinical applications. Multicolor flow cytometry is an effective tool to evaluate the potential contamination of follicular suspensions by leukemic cells. The efficiency of collagenase NB6 was evaluated in comparison to collagenase type IA and Liberase DH, in terms of yield, morphology and viability. A short-term in vitro culture of follicles isolated with collagenase NB6 was conducted for 3 days in a fibrin matrix. A modelization procedure was carried out to detect the presence of leukemic cells in follicular suspensions using multicolor flow cytometry (MFC). No
Mammalian female fertility relies on the proper development of follicles. Right after birth in mouse, oocytes associate with somatic ovarian cells to form follicles. These follicles grow during adult lifetime to produce viable gametes. In this study, we analyzed the role of the ATM and rad3-related (ATR) kinase in mouse oogenesis and folliculogenesis using a hypomorphic mutation of the Atr gene (Murga et al., 2009). Female mice homozygote for this allele have been reported to be sterile. Our data show that female meiotic prophase is not grossly altered when ATR levels are reduced. However, follicle development is majorly compromised since Atr mutant ovaries present a decrease of growing follicles. Comprehensive analysis of follicular cell death and proliferation suggest that wild-type levels of ATR are required to achieve optimal follicular development. Altogether, these findings suggest that reduced ATR expression causes sterility due to defects in follicular progression rather than in meiotic ...
In January 2017, Drs. Donahoe and David Pépin stunned the scientific community with the discovery that AMH/MIS can function both as a contraceptive agent and as an agent which can protect the ovarian reserve during chemotherapy. Their research team showed that MIS can block primordial follicle activation, thereby inhibiting the first step of folliculogenesis and reproduction. Reduction in the number of growing follicles leads to a phenotype of smaller ovaries in the body. This increase in AMH does not reduce the number of primordial follicles, rather it prevents follicular loss. It also can provide contraception without removing reserve oocytes - or immature, female germ cells - during chemotherapy, so natural reproduction can still occur. In mice, treatment with MIS has now been shown to protect the ovarian reserve. As a result, MIS proves to be a reversible contraceptive that functions to mitigate potentially negative effects that chemotherapy may have on mice [7]. Ongoing studies on larger ...
Conclusion: This approach is both simple and effective and it may prove to be an attractive alternative to the standard GnRH agonist long protocol.. Key words: friendly IVF, clomiphene citrate, ICSI, male infertility. As part of the complex physiological patterns of the menstrual cycle in humans, it has been demonstrated that during the first days of the follicular phase of the cycle, early antral follicles exhibit dissimilar sizes, ranging from 2 to 8 mm in diameter (1). This can partly be explained by the inconsistent sensitivity to follicle stimulation hormone (FSH) by the developing oocytes during follicular development (2, 3). This natural phenomenon involves the exposure of early antral follicles to gradient FSH levels during the late luteal phase. During the last days of the menstrual cycle (i.e. late luteal follicular phase transition) paralleling the corpus luteum demise, FSH levels increase progressively to preserve antral follicles from atresia, and ensure their subsequent growth (4). ...
The ovary is the female reproductive organ responsible for the production of both the female gamete, the oocyte, and two major female sex hormones, estradiol and progesterone. During embryonic development, oocytes are formed from primordial germ cells and eventually become surrounded by squamous granulosa cells in a follicular structure, termed primordial. The oocyte numbers encased in primordial follicles are finite at birth and remain arrested in the diplotene stage of meiosis until ovulation or they degenerate through atresia. Once the pool of primordial follicles is depleted, ovarian senescence occurs. We hypothesized that the maternal metabolic changes that occur during lean gestational diabetes mellitus would impact offspring ovarian function both basally and in response to a dietary stressor later in life. We observed impacts on follicle numbers and alterations in the ovarian proteome, suggesting possible impacts on fertility and oocyte quality in relation to in utero and metabolic stressors.
The corpus luteum (yellow body) is a stage in the transformation of an ovarian follicle following ovulation. Granulosa lutein cells: Larger in size, more centrally located; nuclei less densely stained and cytoplasm more abundant. They are transformed cells of the stratum granulosum of the ovarian follicle. Theca lutein cells: Smaller, have less cytoplasm, are more peripherally located, and nuclei stain more densely. They are transformed cells of the theca interna of the ovarian follicle. Both types of cells are epithelioid and produce steroids. The corpus luteum secretes both estrogens and progestins. Progesterone induces changes in the uterine endometrium (secretory phase), in preparation for the implantation of a fertilized ovum, and inhibits spontaneous contractions of the smooth muscle of the uterus so that gestation can be maintained. The vacuoles seen in some cells are due to the lipid droplets dissolved during processing of tissue. Ovarian stroma: Connective tissue stroma, remnant of ...
TY - JOUR. T1 - Expression of the beta-2 adrenergic receptor (ADRB-2) in human and monkey ovarian follicles. T2 - A marker of growing follicles?. AU - Merz, Christoph. AU - Saller, Sabine. AU - Kunz, Lars. AU - Xu, Jing. AU - Yeoman, Richard R.. AU - Ting, Alison. AU - Lawson, Maralee S.. AU - Stouffer, Richard. AU - Hennebold, Jon. AU - Pau, Francis. AU - Dissen, Gregory. AU - Ojeda, Sergio. AU - Zelinski, Mary. AU - Mayerhofer, Artur. PY - 2015. Y1 - 2015. N2 - Background: ADRB-2 was implicated in rodent ovarian functions, including initial follicular growth. In contrast, ADRB-2 expression and function in nonhuman primate and human ovary were not fully known but innervation and significant levels of norepinephrine (NE), which is a ligand at the ADRB-2, were reported in the ovary. Methods: We studied expression of ADRB-2 in human and rhesus monkey ovary (RT-PCR, immunohistochemistry; laser micro dissection) and measured levels of norepinephrine (NE; ELISA) in monkey follicular fluid (FF). 3D ...
Definition of follicle cells in the Legal Dictionary - by Free online English dictionary and encyclopedia. What is follicle cells? Meaning of follicle cells as a legal term. What does follicle cells mean in law?
Consequences of eight consecutive applications of equine chorionic gonadotropin on ovarian follicle development and ovulation in bos indicus cows . Isaac Santos Gil ; Tracy Ferreira Lacerda ; Mauricio Gomes Favoreto ; Bárbara Loureiro ;Ciência Rural 2016, 46 (11). Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
TY - JOUR. T1 - A role for neurotransmitters in early follicular development. T2 - Induction of functional follicle-stimulating hormone receptors in newly formed follicles of the rat ovary. AU - Mayerhofer, Artur. AU - Dissen, Gregory A.. AU - Costa, Maria E.. AU - Ojeda, Sergio R.. PY - 1997/1/1. Y1 - 1997/1/1. N2 - The initiation of follicular growth in the mammalian ovary is a gonadotropin-independent phenomenon. Although some of the intraovarian signaling molecules that control the later phases of this process have been recently identified, the factors involved in the acquisition of gonadotropin receptors by early growing follicles have not been fully defined. In the rat, development of the ovarian innervation precedes the onset of folliculogenesis and occurs before follicles acquire responsiveness to gonadotropins. Because vasoactive intestinal polypeptide (VIP) and norepinephrine (NE), two of the neurotransmitters contained in ovarian nerves, are present in the ovary before the gland ...
TY - JOUR. T1 - Involvement of Gαs-proteins in the action of relaxin-like gonad-stimulating substance on starfish ovarian follicle cells. AU - Mita, Masatoshi. AU - Haraguchi, Shogo. AU - Watanabe, Miho. AU - Takeshige, Yuki. AU - Yamamoto, Kazutoshi. AU - Tsutsui, Kazuyoshi. PY - 2014/9/1. Y1 - 2014/9/1. N2 - Gonad-stimulating substance (GSS) in starfish is the only known invertebrate peptide hormone responsible for final gamete maturation, rendering it functionally analogous to gonadotropins in vertebrates. In breeding season (stage V), GSS stimulates oocyte maturation to induce 1-methyladenine (1-MeAde) by ovarian follicle cells. The hormonal action of GSS is mediated through the activation of its receptor, G-proteins and adenylyl cyclase. It has been reported that GSS fails to induce 1-MeAde and cyclic AMP (cAMP) production in follicle cells of ovaries during oogenesis (stage IV). This study examined the regulatory mechanism how ovarian follicle cells acquire the potential to respond to GSS ...
The present study examined the follicular populations prior to and during superovulation and investigated their relationship with superovulatory response in crossbred cattle. Eleven animals were administered i.m. 8 doses of Folltropin of 2.5 ml each (1.75 mg/ml) spread over 4 days beginning on Day 10 of oestrous cycle, and 30 and 20 mg Lutalyse was given along with the 5th and 6th injections of Folltropin respectively, to induce luteolysis. The animals were artificially inseminated 48, 60 and 72 h after the first Lutalyse injection. The number of corpora lutea (CL) was recorded by palpation per rectum and embryos were recovered non-surgically on Day 6 (Day 0 = day of superoestrus). The ovarian follicular population was examined by transrectal ultrasonography 15 h prior to and 52 h after the first FSH injection, and then on the day of superoestrus and the day of flushing. The follicles were classified on the basis of diameter as small (3-5 mm), medium (6-9 mm) and large (> 10 mm). The total ...
TY - JOUR. T1 - VEGFR-3 neutralization inhibits ovarian lymphangiogenesis, follicle maturation, and murine pregnancy. AU - Rutkowski, Joseph M.. AU - Ihm, Jong Eun. AU - Lee, Seung Tae. AU - Kilarski, Witold W.. AU - Greenwood, Veronique I.. AU - Pasquier, Miriella C.. AU - Quazzola, Alexandra. AU - Trono, Didier. AU - Hubbell, Jeffrey A.. AU - Swartz, Melody A.. PY - 2013/11/1. Y1 - 2013/11/1. N2 - Lymphatic vessels surround follicles within the ovary, but their roles in folliculogenesis and pregnancy, as well as the necessity of lymphangiogenesis in follicle maturation and health, are undefined. We used systemic delivery of mF4-31C1, a specific antagonist vascular endothelial growth factor receptor 3 (VEGFR-3) antibody to block lymphangiogenesis in mice. VEGFR-3 neutralization for 2 weeks before mating blocked ovarian lymphangiogenesis at all stages of follicle maturation, most notably around corpora lutea, without significantly affecting follicular blood angiogenesis. The numbers of oocytes ...
TY - JOUR. T1 - Identification and genetic localization of mRNAs from ovarian follicle cells of Drosophila melanogaster. AU - Spradling, Allan C.. AU - Mahowald, Anthony P.. PY - 1979. Y1 - 1979. N2 - RNA synthesis in ovarian follicles of Drosophila melanogaster was studied by methods which eliminate experimentally induced alterations in gene expression. Gel electrophoresis of follicular RNA, labeled after injection of precursors into females, revealed qualitative and quantitative differences in synthesis during the course of oogenesis. A highly heterogeneous group of poly(A)-containing RNAs is produced during much of the course of follicular development. However, post-vitellogenic stages synthesize a small number of stage-specific poly(A)-containing RNAs. During this period, RNA synthesis is known to take place primarily in the follicle cells, which are engaged in the production of the endochorion and exochorion. Two intense bands of nonmitochondrial poly(A)+ RNA are labeled between stage 11 ...
Looking for online definition of Antral follicle in the Medical Dictionary? Antral follicle explanation free. What is Antral follicle? Meaning of Antral follicle medical term. What does Antral follicle mean?
Dr Cecconi said that little had been done to study the potential role for ELF-EMF on the development of mammalian reproduction so their study was designed to see whether ELF-EMF could affect ovarian follicle development in mice.. They exposed isolated mouse ovarian follicles that were at the pre-antral development stage for five days to ELF-EFM at 33Hz or 50Hz frequencies. On day five, only around a third of the follicles exposed to 33Hz and half of those exposed to 50Hz developed antral cavities compared with 80% of controls.. We dont know yet why this happens but our results indicate ELF-EMF may affect the regulatory mechanism controlling the somatic (non-germ) cells in the follicle.. Dr Cecconi said that more research would be needed to discover exactly how ELF-EMF was impairing the physiological process. It was also important to undertake research to see whether ELF-EMF exposure produced a similar effect on human ovarian follicles.. At this stage we have no idea whether the same effect ...
During the autumn/winter/spring periods of three seasons, 32 pure and crossbred Irish Draught mares were stabled and maintained under extended daylength of 16 hours light beginning December 16th. Prior to the first ovulatory oestrus following a period of acyclicity (seasonal anoestrus), all mares were examined at intervals of no more than 7-10 days, more frequently when follicular activity increased and at least once daily for at least 11 days before ovulation and when a follicle reached 35 mm. All follicles of 20 mm or larger were measured and recorded. In the absence of any follicle in either ovary larger than 20 mm, the diameter of any smaller follicle was also recorded. It was therefore possible to trace back from the time of ovulation, the diameter of the ovulatory follicle during its development. Where over several days, one follicle in an ovary regressed, it was assumed that another initially smaller follicle in the same ovary had grown to overtake the larger and progressed to ovulation. ...
Daniel A. Dumesic, M.D., JoAnne S. Richards, Ph.D.. Volume 100, Issue 1, Pages 23-38, July 2013. Abstract:. Activation of primordial follicles into the growing pool, selection of the dominant follicle and its eventual ovulation require complex endocrine and metabolic interactions, as well as intraovarian paracrine signals to coordinate granulosa cell proliferation, theca cell differentiation and oocyte maturation. Early preantral follicle development relies mostly upon mesenchymal-epithelial cell interactions, intraovarian paracrine signals and oocyte-secreted factors, while development of the antral follicle depends upon circulating gonadotropins as well as locally-derived regulators. In women with polycystic ovary syndrome (PCOS), ovarian hyperandrogenism, hyperinsulinemia from insulin resistance and altered intrafollicular paracrine signaling perturb activation, survival, growth and selection of follicles, causing accumulation of small antral follicles within the periphery of the ovary, ...
Follicular (preovulatory, estrogenic) phase. It entails maturation of the ovarian follicle and secretion of estrogen hormone. Under the effect of the follicle stimulating hormone (F.S.H.) secreted by the anterior pituitary gland, many primary ovarian follicles grow at the same time, but only one of them reaches full maturation into a Graafian follicle. The other follicles undergo atresia (atretic follicles).The developing Graafian follicle secretes estrogen in the liquor folliculi. Estrogen is responsible for the proliferative phase of the uterine cycle.. Ovulation. It is the process of rupture of the Graafian follicle and release of the mature ovum from the ovary. It occurs once every lunar month (about 28 days) during the fertile period of the human female. It does not occur during pregnancy. It sometimes occurs during lactation. The time of ovulation is variable but it is usually on the 14th day of the ovarian cycle. Ovulation occurs at about 14 days (± one day) before the beginning of the ...
Synchronization programs aim to effectively create an ideal hormonal environment to successfully induce the development of a dominant follicle containing a healthy oocyte that is capable of being fertilized and developing to term. It has been repeatedly suggested that greater gonadotropin stimulation for a finite period during follicular development may enhance fertility in beef cattle. It was hypothesized that decreased progesterone (P4) concentrations during early follicular development would result in increased luteinizing hormone (LH) pulse frequency, leading to oocytes of greater developmental capacity, ultimately increasing pregnancy rate to AI in beef cattle. In the first experiment, decreased P4 concentration during early follicular development and its effect on pregnancy rate to timed-AI and estrus-AI were investigated in multiparous beef cows in Ohio (Experiment 1.1) and Montana (Experiment 1.2). In both experiments, P4 concentrations at the end of P4 treatment were, as designed, greater in
There is an increasing interest in the manipulation of ovarian follicular populations in large domestic animals because this could prove beneficial for assisted reproductive techniques such as ovum pick-up (OPU). The aim of the present study was to evaluate the effects of deslorelin slow-release implants (SRI) on the interovulatory interval, antral follicle count (AFC), number of follicles of different size ranges and plasma anti-Muellerian hormone (AMH) concentration in mares. To synchronize their estrous cycles, Haflinger mares (n = 12) were treated twice with a PGF2α analogue. One day after the second injection (day 0), mares received a 9.4 mg deslorelin SRI (group DES, n = 6) or 1.25 mg deslorelin in a short-acting formulation (CON; n = 6), respectively. Regular transrectal ultrasonography of the genital tract was performed and blood samples were collected for the analysis of progesterone, AMH and gonadotrophins. The interval from implant insertion to the first spontaneous ovulation was 23.8 ± 10
Advanced maternal age has been shown to influence follicular and luteal dynamics in bovine ovary resulting in reduced fertility. The overall objective of the four studies presented in this thesis is to identify the maternal age-associated transcriptional changes in granulosa cells of the dominant follicles during follicle development. In the first study, mRNA expression levels of housekeeping genes were measured by real-time quantitative PCR (RT-qPCR) in granulosa cells of dominant follicles and FSH-stimulated follicles to select and validate suitable reference genes for relative gene expression analyses during maternal and follicular aging. Stability of six reference genes (GAPDH, ACTB, EIF2B2, UBE2D2, SF3A1 and RNF20) was analyzed using GeNorm, DeltaCT and NormFinder programs and comprehensive ranking order was determined based on these programs. Geometric mean of multiple genes (UBE2D2, EIF2B2, GAPDH and SF3A1) was more appropriate reference control than individual genes for the comparison of ...
To date, empty follicle syndrome (EFS) has only been reported in GnRH agonist down‐regulated IVF cycles. Some cases have been successfully treated by changing the batch, or by repeating the dose of hCG. A case of EFS was observed in both GnRH antagonist and GnRH agonist down‐regulated IVF cycles when final oocyte maturation was triggered using urinary hCG (u‐hCG). Failure to retrieve oocytes occurred, despite administration of a further dose of u‐hCG from a different batch and a delayed repeated oocyte recovery performed in the second GnRH agonist down‐regulated cycle. A successful oocyte recovery cycle was achieved after triggering of an endogenous gonadotrophin surge using GnRH agonist in an antagonist down‐regulated cycle. Nine oocytes were readily retrieved from 10 follicles, at 36 h after GnRH agonist administration, and eight of these fertilized normally. Two good quality embryos were used for fresh transfer and four were cryopreserved for future use. EFS can occur in GnRH ...
FSH stimulates the growth and recruitment of immature ovarian follicles in the ovary. In early (small) antral follicles, FSH is the major survival factor that rescues the small antral follicles (2-5 mm in diameter for humans) from apoptosis (programmed death of the somatic cells of the follicle and oocyte). In the luteal-follicle phase transition period the serum levels of progesterone and estrogen (primarily estradiol) decrease and no longer suppress the release of FSH, consequently FSH peaks at about day three (day one is the first day of menstrual flow). The cohort of small antral follicles is normally sufficient in number to produce enough Inhibin B to lower FSH serum levels. In addition, there is evidence that gonadotropin surge-attenuating factor produced by small follicles during the first half of the follicle phase also exerts a negative feedback on pulsatile luteinizing hormone (LH) secretion amplitude, thus allowing a more favorable environment for follicle growth and preventing ...
Left: The pituitary gonadotropins FSH and LH are part of the hypothalamic-pituitary-gonadal axis that coordinately regulates the menstrual (in humans) or estrous (in nonhuman mammals) cycle by extensive feedback loops. FSH controls follicular granulosa cell (GC) growth and estradiol production, while LH controls ovulation and follicular luteinization. Right: A cross section of a mouse ovary is shown, demonstrating the main cell types and follicle stages. Ovarian follicles are composed of a single oocyte surrounded by somatic cells (granulosa cells) and thecal cells. Follicles grow from primordial (not shown) to primary and secondary stages independent of the pituitary gonadotropins. FSH stimulates growth to the preovulatory follicle stage, characterized by granulosa cells that directly surround the oocyte (cumulus cells) and those that make up the bulk of the wall of the follicle. Following the LH surge, the follicle erupts through the ovarian surface (OSE), and the remaining cells of the ...
Dorsal-ventral (DV) patterning of the Drosophila embryo begins during oogenesis and relies on a series of intercellular signaling events in the egg chamber between the germline-derived oocyte and the somatically derived follicle cells (Ray and Schüpbach, 1996; Nilson and Schüpbach, 1999). The initial asymmetry for embryonic DV polarity is established at mid-oogenesis in the oocyte and is subsequently conveyed to the surrounding follicle cells. Spatial information generated within the follicular epithelium is then transmitted back to the germline, and is interpreted by the embryo after fertilization.. The initial polarizing signal from the oocyte to the follicle cells is determined by gurken (grk), which encodes a secreted transforming growth factor α (TGFα)-like protein (Neuman-Silberberg and Schüpbach, 1993). During mid-oogenesis, grk mRNA associated with the oocyte nucleus is localized to the dorsal anterior corner of the oocyte, resulting in restricted distribution of Grk protein and the ...
Looking for online definition of membrana adventitia in the Medical Dictionary? membrana adventitia explanation free. What is membrana adventitia? Meaning of membrana adventitia medical term. What does membrana adventitia mean?
The most common reason of anovulation is a hormonal imbalance that can cause the symptoms of PCOS (3,16). According to histological evaluation in PCOS, the number of primordial follicles in the ovary was not distinct from the ones in normal ovaries, but the number of primary and secondary follicles was shown to be significantly higher than in a normal ovary (17). Nevertheless, the autocrine-paracrine factors in the follicular microenvironment that showed variability in certain stages of folliculogenesis remains uncertain. Therefore, in our study we intended to clarify which stage of folliculogenesis in PCOS showed GDF9 and BMP15 expression changes.. Factors secreted by the oocyte are essential for follicular development and oocyte maturation (4,10). Previous studies indicate that oocyte-derived GDF9 and BMP15 support the follicle growth in the pre-antral and antral follicle stages, and they also play a role in the regulation of oocyte development and maturation (18,19). Zhao et al. (13) showed ...
TY - JOUR. T1 - Changes in gene expression involved in energy utilization during chicken follicle development. AU - Seol, H. S.. AU - Sato, Kan. AU - Murakami, Hitoshi. AU - Toyomizu, Masaaki. AU - Akiba, Yukio. N1 - Funding Information: These studies were supported by Grants-in-Aid (Nos. 152008026 and 14760175) from the Ministry of Education, Science and Culture of Japan. The authors would like to thank Ueda Masatoshi for competent and indispensable technical assistance. Special thanks are given to Iwaya Farm in Sendai for providing laying chickens for this study. Copyright: Copyright 2008 Elsevier B.V., All rights reserved.. PY - 2006/10. Y1 - 2006/10. N2 - Ovarian follicle development in egg-laying species is characterized by rapid growth in 7 days prior to ovulation when DNA and protein synthesis is markedly increased in the granulosa and theca cells. However, energy and substrate sources to facilitate the extensive DNA and protein synthesis necessary for folliculogenesis have not been ...
Required for ovarian folliculogenesis. Promotes primordial follicle development. Stimulates granulosa cell proliferation. Promotes cell transition from G0/G1 to S and G2/M phases, through an increase of CCND1 and CCNE1 expression, and RB1 phosphorylation. It regulates STAR expression and cAMP-dependent progesterone release in granulosa and thecal cells. Attenuates the suppressive effects of activin A on STAR expression and progesterone production by increasing the expression of inhibin B. It suppresses FST and FSTL3 production in granulosa-lutein cells.
I am a developmental/reproductive biologist studying the development of mammalian oocytes, the cells that become eggs. The focus of my research is on the complex interactions between developing oocytes and their companion follicular somatic cells, the granulosa cells. I found that oocytes are not simply passive recipients of nutrients and signals from ovarian follicular somatic cells, as once believed, but rather actively promote the functions of somatic cells needed to support oocyte development and regulate meiosis. I originated the concept of an oocyte-granulosa cell regulatory loop in which bi-directional communication between the oocyte and companion granulosa cells is essential for both normal oocyte and follicular development. A major goal of my current research is to define the components of this regulatory loop and their functions. I also achieved the first complete development of mammalian oocytes in vitro. This included in vitro initiation of primordial follicle development, oocyte ...
The fluid surrounding the Ovum and Granulosa Cells in the Graafian Follicle (Ovarian Follicle). The follicular fluid contains sex Steroids, Glycoprotein Hormones, Plasma Proteins, Mucopolysaccharides, and Enzymes ...
Your ovaries are the reservoir for your eggs. Eggs are the cells which carry half of the information (genetic blue print) necessary for creating a baby. Such precious egg cells are stored, nourished and protected within specialized structures in ovaries called follicles. A female foetus at around 18-22 weeks of gestation contains about 2,000,000 follicles in its ovaries and each follicle contains one egg. The follicles which are carrying the eggs are lost continuously (depleted) during the life time of a female and at around menopause only less than 1000 follicles will remain. A woman releases approximately 400 eggs during her lifetime (one egg each month from the time of attaining puberty until reaching menopause). A female ovary carries several immature follicles (and hence several eggs!) but not all the follicles will become mature enough to release a functional egg cell. This means that more than 99.9999 % of the follicles (and hence the eggs) are simply lost ...
TY - JOUR. T1 - Dacarbazine depletes the ovarian reserve in mice and depletion is enhanced with age. AU - Winship, Amy L.. AU - Bakai, Monika. AU - Sarma, Urooza. AU - Liew, Seng H.. AU - Hutt, Karla J.. PY - 2018/4/25. Y1 - 2018/4/25. N2 - Dacarbazine is commonly administered for the treatment of cancers prevalent in reproductive age females. However, investigations of off-target effects of dacarbazine on the ovary are limited. We assessed the impact of dacarbazine on the ovarian reserve of primordial follicles, essential for fertility. Eight week and 6 month old C57BL/6 J mice were administered with dacarbazine or saline on day (d)0 and d7, then sacrificed after 12 hours (h), or 14d (n = 4-5/group). Follicle numbers, follicle density, serum AMH and corpora lutea were quantified and estrous cyclicity monitored. In reproductively young mice, dacarbazine did not affect primordial follicle numbers at 12 h, but resulted in a 36% reduction at 14d (p , 0.05). Dacarbazine-mediated primordial follicle ...
A membrana amniótica é uma membrana translucida sendo a membrana mais interna da cavidade amniótica, formada por uma monocamada de células epiteliais disposta sobre uma membrana basal. Com o crescente...
Looking for membrana abdominis? Find out information about membrana abdominis. multilayered membrane which lines the abdominal cavity, and supports and covers the organs within it. The part of the membrane that lines the abdominal... Explanation of membrana abdominis
Follicles which have been stimulated to develop progress through primary and secondary stages to become mature tertiary or Graafian follicles, in which a large fluid-filled cavity, the antrum, is surrounded by many layers of granulosa cells. Stromal cells around the follicle differentiate into the theca interna and the theca externa (not apparent in this image). Androgen from cells in the theca interna is processed to estrogen in granulosa cells; the estrogen then enters circulation via blood vessels which form in the theca. The cumulus oophorus, containing the oocyte, seldom appears in random sections such as this. ...
ROCKLAND, MD - Sept. 30 /PRNewswire/ -- Serono, Inc. announced today that the Reproductive Health Drugs Advisory Committee of the U.S. Food and Drug Administration (FDA) issued a favorable recommendation for Luveris® in Seronos proposed indication of follicular development. Luveris® (lutropin alfa for injection) administered with follitropin alfa for injection, is proposed for the indication of stimulation of follicular development in infertile hypogonadotropic hypogonadal (HH) women with profound luteinizing hormone deficiency (LH The FDA had previously recommended that Serono study an endpoint of ovulation rates, an endpoint frequently used for products in ovulation induction. However, the Committee agreed that in this rare patient population the endpoint of follicular development was appropriate.. We are very pleased with the recommendation of the Advisory Committee supporting the efficacy of Luveris® for follicular development in this rare patient population and will continue to work ...
When the dominant antral follicle ovulates, slight localised haemorrhage occurs at the site of ovulation and fills the former cavity. The small amount of bloody tissue can be observed by the naked eye. Loss of fluid from the antral cavity causes the follicle to collapse into many folds. As a result, some granulosal and thecal layers are pushed into the apex of the ruptured follicle. The protrusion of tissue and ruptured blood vessels forms a structure known as the corpus haemorrhagicum. Following this, the theca interna and granulosa cells differentiate into large and small luteal cells. Luteal cells contain increased quantities of lipid droplets and the pigment lutein. As the blood is resorbed, a solid corpus luteum is formed by proliferation of granulosa and theca intera cells as well as blood vessels. This remains on the surface of the ovary. In the non-pregnant animal, corpora lutea are transient structures. Cyclic corpora lutea undergo proliferation and vascularisation directly after ...
When the dominant antral follicle ovulates, slight localised haemorrhage occurs at the site of ovulation and fills the former cavity. The small amount of bloody tissue can be observed by the naked eye. Loss of fluid from the antral cavity causes the follicle to collapse into many folds. As a result, some granulosal and thecal layers are pushed into the apex of the ruptured follicle. The protrusion of tissue and ruptured blood vessels forms a structure known as the corpus haemorrhagicum. Following this, the theca interna and granulosa cells differentiate into large and small luteal cells. Luteal cells contain increased quantities of lipid droplets and the pigment lutein. As the blood is resorbed, a solid corpus luteum is formed by proliferation of granulosa and theca intera cells as well as blood vessels. This remains on the surface of the ovary. In the non-pregnant animal, corpora lutea are transient structures. Cyclic corpora lutea undergo proliferation and vascularisation directly after ...
Maturation of the mammalian oocyte is characterized in part by dissolution of the nuclear envelope, or germinal vesicle breakdown (GVB). By fluorescence microscopy after vital uptake of acridine orange (AO), redistribution and perinuclear accumulation of organelles corresponding to lysosomes occur before GVB in rat oocytes undergoing meiotic maturation in vitro. In follicle-enclosed oocytes explanted during the preovulatory gonadotropin surge (GS) and individually cultured as such in chemically defined medium at approximately 22 degrees C, lysosomes aggregated into disperse clusters after 30 min; by 60 min, perinuclear concentration of lysosomes and their essential disappearance from the cortical ooplasm were observed. GVB occurred within 120 min. In contrast, follicle-enclosed oocytes explanted before the GS displayed a generally homogeneous distribution of lysosomes and intact GV for up to 5 h in culture. In oocytes aspirated from follicles before the GS, partially denuded of granulosa cells, ...
Abstract. Uncovers the mechanism of how ovarian follicles can respond to bacterial infections at a distant site.Granulosa cells of ovarian follicles have innate immune capabilities.First report in any species of LPS toxin of Gram-negative bacteria causing direct damage to oocytes.. ...
The mammalian oocyte develops within a complex of somatic cells known as a follicle, within which signals from the somatic cells regulate the oocyte, and signals from the oocyte regulate the somatic cells. Because isolation of the oocyte from the follicle disrupts these communication pathways, oocyte physiology is best studied within an intact follicle. Here we describe methods for quantitative microinjection of follicle-enclosed mouse oocytes, thus allowing the introduction of signaling molecules as well as optical probes into the oocyte within its physiological environment.
Citation: N/A Interpretive Summary: Successful reproduction is dependent on the ability of an animal to release a viable oocyte at the appropriate time of her estrous cycle. Yet little is known about the mechanisms that control the development of the ovarian follicles that support developing oocytes. While several hundred follicles begin to grow during each estrous cycle, only one generally ovulates. Cell lculture studies have demonstrated that the hormone insulin-like growth factor I (IGF-I) enhances the ability of cells from follicles to proliferate and secrete steroids (i.e., estrogens), two aspects associated with follicle maturation. In addition, IGF-I has been shown to be beneficial for in vitro maturation of oocytes. The present study demonstrated that concentrations of IGF-I did not differ between fluid from follicles destined to ovulate and those destined to die. However, the study determined that IGF-binding proteins (IGFBPs) were much less prevalent in follicles destined to ovulate ...
Population-specific incidence of testicular ovarian follicles in Xenopus laevis from South Africa : A potential issue in endocrine ...
Reactive oxygen species are produced during normal ovarian function, and they may also be produced as a result of toxicant metabolism. Our earlier work demonstrated a role for reactive oxygen species in mediating spontaneous apoptosis in follicles deprived of hormonal support and apoptosis caused by exposure to ovarian toxicants. We discovered that reactive oxygen species increased in ovarian follicles cultured without gonadotropin support prior to any increase in endpoints of apoptosis and that follicle stimulating hormone stimulated synthesis of the antioxidant glutathione (GSH) and suppressed the rise in reactive oxygen species. We further showed that GSH depletion in cultured follicles reversed the protective, suppressive effect of follicle stimulating hormone on reactive oxygen species and on apoptosis. This work provides evidence that the protective effects of follicle stimulating hormone are mediated in part via upregulation of GSH synthesis. We also showed that increased generation of ...
Human follicle stimulating hormone (hFSH) is a gonadotropin involved in the stimulation of ovarian follicles in women and the proper maturation of sperm in men. The receptor, hFSHR, belongs to the G protein-coupled receptor class of hormone receptors and is found embedded in cell membranes. Binding of hFSH to its receptor initiates a complex downstream signaling pathway, the precise intricacies of which are still being determined. Previous research in has suggested that hFSHR is located in lipid rafts, microdomains of the membrane that are made up of a higher concentration of cholesterol, glycosphingolipids, and the protein caveolin.. To better understand the mechanism and effect of hFSHR lipid raft residency, cells from the HEK293 line were treated with a peptide mimetic of transmembrane domain 4 of hFSHR. This peptide includes a sequence consistent with a motif shown in other proteins to interact with caveolin. The putative caveolin interaction motif (phiXphiXXXXphiXXphi) was synthesized along ...
Light microscopy of the fetal primate ovary about 20 weeks of gestation. The ovary is densely populated with oocytes (female germ cells) enclosed with a layer of follicle cells which together are known as follicles. The earliest follicles are called primordial follicles. In most species the fetal ovary is massively oversupplied with oocytes/follicles; in humans there may be up to 5 million per ovary. For reasons that remain unknown the majority (approximately 85%) of follicles die with a few hundred thousand surviving in each ovary at birth. Magnification x180 when narrow width printed at 10 cm. - Stock Image C024/0084
Meiosis in mammalian oocytes pauses in prophase until luteinizing hormone (LH) releases this arrest. One suggestion is that LH does this by closing the gap junctions between the somatic cells that surround the oocyte, thus blocking the transmission of a meiosis-inhibitory signal to oocytes. Now, Norris and co-workers show that LH-induced MAP kinase-dependent gap junction phosphorylation and closure is one of two paths to meiotic resumption in mouse ovarian follicles (see p. 3229). By monitoring the diffusion of fluorescent tracers in intact follicles, the researchers show for the first time that LH decreases the permeability of connexin 43-containing gap junctions between the somatic cells before nuclear envelope breakdown (NEBD; the start of the prophase-metaphase transition) occurs in oocytes. MAP kinase-dependent phosphorylation of connexin 43 causes this decreased permeability, they report. However, surprisingly, inhibition of MAP kinase activation does not prevent NEBD. Thus, they suggest, ...
During the development of oocytes from early antral follicles (EAFs) to antral follicles (AFs), the mitochondrial DNA copy number (Mt DNA number) increases, and granulosa cells markedly proliferate. This study examined the effect of supplementation of culture medium with estradiol-17β (E2) on the in vitro growth of oocytes, and increases in the Mt DNA number, and telomere length during the in vitro culture of oocytes derived from EAFs (0.4-0.7 mm in diameter). The E2 supplementation improved antrum formation and the ratio of oocytes reaching the metaphase II (MII) stage, and there was a significant difference in these values between addition E2 concentrations of 10 μg/ml and 0.1 μg/ml. When the oocytes were cultured in the medium containing 10 μg/ml E2, the Mt DNA number determined by real-time polymerase chain reaction (PCR) significantly increased, and the ratio of the Mt DNA number at the end of culture to the Mt DNA number at the beginning of the culture was greatly different among cows, ...