scholarly journals Biology and Biotechnology of Follicle Development

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Gustavo Adolfo Palma ◽  
Martin Eduardo Argañaraz ◽  
Antonio Daniel Barrera ◽  
Daniela Rodler ◽  
Adrian Ángel Mutto ◽  
...  

Growth and development of ovarian follicles require a series of coordinated events that induce morphological and functional changes within the follicle, leading to cell differentiation and oocyte development. The preantral early antral follicle transition is the stage of follicular development during which gonadotropin dependence is obtained and the progression into growing or atresia of the follicle is made. Follicular growth during this period is tightly regulated by oocyte-granulosatheca cell interactions. A cluster of early expressed genes is required for normal folliculogenesis. Granulosa cell factors stimulate the recruitment of theca cells from cortical stromal cells. Thecal factors promote granulosa cell proliferation and suppress granulosa cell apoptosis. Cell-cell and cell-extracellular matrix interactions influence the production of growth factors in the different follicular compartments (oocyte, granulosa, and theca cells). Several autocrine and paracrine factors are involved in follicular growth and differentiation; their activity is present even at the time of ovulation, decreasing the gap junction communication, and stimulating the theca cell proliferation. In addition, the identification of the factors that promote follicular growth from the preantral stage to the small antral stage may provide important information for the identification for assisted reproduction techniques.

Reproduction ◽  
2010 ◽  
Vol 140 (2) ◽  
pp. 295-303 ◽  
Author(s):  
Jennifer L Juengel ◽  
Lisa J Haydon ◽  
Brigitta Mester ◽  
Brian P Thomson ◽  
Michael Beaumont ◽  
...  

IGFs are known to be key regulators of ovarian follicular growth in eutherian mammals, but little is known regarding their role in marsupials. To better understand the potential role of IGFs in the regulation of follicular growth in marsupials, expression of mRNAs encoding IGF1, IGF2, IGF1R, IGF-binding protein 2 (IGFBP2), IGFBP4 and IGFBP5 was localized by in situ hybridization in developing ovarian follicles of the brushtail possum. In addition, the effects of IGF1 and IGF2 on granulosa cell function were tested in vitro. Both granulosa and theca cells synthesize IGF mRNAs, with the theca expressing IGF1 mRNA and granulosa cell expressing IGF2 mRNA. Oocytes and granulosa cells express IGF1R. Granulosa and theca cells expressed IGFBP mRNAs, although the pattern of expression differed between the BPs. IGFBP5 mRNA was differentially expressed as the follicles developed with granulosa cells of antral follicles no longer expressing IGFBP5 mRNA, suggesting an increased IGF bioavailability in the antral follicle. The IGFBP protease, PAPPA mRNA, was also expressed in granulosa cells of growing follicles. Both IGF1 and IGF2 stimulated thymidine incorporation but had no effect on progesterone production. Thus, IGF may be an important regulator of ovarian follicular development in marsupials as has been shown in eutherian mammals.


Author(s):  
P. Bagavandoss ◽  
JoAnne S. Richards ◽  
A. Rees Midgley

During follicular development in the mammalian ovary, several functional changes occur in the granulosa cells in response to steroid hormones and gonadotropins (1,2). In particular, marked changes in the content of membrane-associated receptors for the gonadotropins have been observed (1).We report here scanning electron microscope observations of morphological changes that occur on the granulosa cell surface in response to the administration of estradiol, human follicle stimulating hormone (hFSH), and human chorionic gonadotropin (hCG).Immature female rats that were hypophysectcmized on day 24 of age were treated in the following manner. Group 1: control groups were injected once a day with 0.1 ml phosphate buffered saline (PBS) for 3 days; group 2: estradiol (1.5 mg/0.2 ml propylene glycol) once a day for 3 days; group 3: estradiol for 3 days followed by 2 days of hFSH (1 μg/0.1 ml) twice daily, group 4: same as in group 3; group 5: same as in group 3 with a final injection of hCG (5 IU/0.1 ml) on the fifth day.


2004 ◽  
Vol 183 (1) ◽  
pp. 1-17 ◽  
Author(s):  
P D Taylor ◽  
S G Hillier ◽  
H M Fraser

Angiogenesis is required for normal follicular development but the role of gonadotrophins in the control of follicular angiogenesis remains to be elucidated. This study investigated the effects of treatment with GnRH antagonist in vivo on follicular development and angiogenesis in the marmoset. GnRH antagonist was administered on either follicular day 0 or day 5 of the 10-day follicular phase with ovaries collected on day 10. Ovaries from control marmosets were studied at day 5 (mid follicular phase) and day 10 (periovulatory period). Ovaries were fixed, serial sectioned and subjected to morphological analysis and immunocytochemistry to determine cell proliferation and follicular endothelial cell area and in situ hybridization to assess changes in expression of vascular endothelial growth factor (VEGF). Treatment with GnRH antagonist from day 0–10 resulted in an absence of dominant preovulatory follicles seen in controls. In the remaining tertiary follicles granulosa, theca and endothelial cell proliferation was reduced, resulting in a minor reduction in vascular density. However, VEGF mRNA expression was unaffected by treatment. Treatment from day 5–10 did not prevent development of ovulatory size follicles, but they were atretic and lacked VEGF mRNA. These results suggest that while VEGF expression in the preovulatory follicle is under gonadotrophic control it is not dependent on normal gonadotrophin secretion in tertiary follicles, indicating that there are other paracrine factors regulating VEGF expression in the developing ovarian follicle.


2010 ◽  
Vol 24 (3) ◽  
pp. 540-551 ◽  
Author(s):  
Guidong Yao ◽  
Mianmian Yin ◽  
Jie Lian ◽  
Hui Tian ◽  
Lin Liu ◽  
...  

Abstract Many members of the TGF-β superfamily are indicated to play important roles in ovarian follicular development, such as affecting granulosa cell function and oocyte maturation. Abnormalities associated with TGF-β1 signaling transduction could result in female infertility. MicroRNAs (miRNAs), as small noncoding RNAs, were recently found to regulate gene expression at posttranscriptional levels. However, little is known about the role of miRNAs in TGF-β-mediated granulosa cell proliferation and granulosa cell function. In this study, the miRNA expression profiling was identified from TGF-β1-treated mouse preantral granulosa cells (GCs), and three miRNAs were found to be significantly up-regulated and 13 miRNAs were down-regulated. Among up-regulated miRNAs, miR-224 was the second most significantly elevated miRNA. This up-regulation was attenuated by treatment of GCs with SB431542 (an inhibitor of TGFβ superfamily type I receptors, thus blocking phosphorylation of the downstream effectors Smad2/3), indicating that miR-224 expression was regulated by TGF-β1/Smads pathway. The ectopic expression of miR-224 can enhance TGF-β1-induced GC proliferation through targeting Smad4. Inhibition of endogenous miR-224 partially suppressed GC proliferation induced by TGF-β1. In addition, both miR-224 and TGF-β1 can promote estradiol release from GC, at least in part, through increasing CYP19A1 mRNA levels. This is the first demonstration that miRNAs can control reproductive functions resulting in promoting TGF-β1-induced GC proliferation and ovarian estrogen release. Such miRNA-mediated effects could be potentially used for regulation of reproductive processes or for treatment of reproductive disorders.


Zygote ◽  
1996 ◽  
Vol 4 (04) ◽  
pp. 317-321 ◽  
Author(s):  
Barbara C. Vanderhyden

Investigations of strains of mice defective in germ cell development have revealed the importance of oocytes for the initial stages of folliculogenesis (Pellaset al., 1991; Huanget al., 1993). Various aspects of follicular development are dependent upon and/or influenced by the presence of oocytes, including granulosa cell proliferation (Vanderhydenet al., 1990, 1992) and cumulus expansion (Buccioneet al., 1990; Salustriet al., 1990; Vanderhydenet al., 1990; Vanderhyden, 1993). We are investigating the possibility that oocytes influence one of the primary functions of granulosa cells: steroidogenesis. In many species, granulosa cells removed from preovulatory follicles luteinisein vitro(Channinget al., 1982), presumably due to loss of contact with follicular luteinisation inhibitory factor(s). Indeed, follicular fluid can prevent granulosa cell luteinisationin vitro(Ledwitz-Rigbyet al., 1977). Follicular fluid, however, may simply be the medium for transport of factors secreted by oocytes to regulate granulosa cell activities.


1999 ◽  
Vol 13 (6) ◽  
pp. 410-419 ◽  
Author(s):  
T. Maruo ◽  
J. B. Laoag-Fernandez ◽  
S. Takekida ◽  
X. Peng ◽  
J. Deguchi ◽  
...  

2011 ◽  
Vol 23 (1) ◽  
pp. 32 ◽  
Author(s):  
J. Buratini ◽  
C. A. Price

Considerable attention is currently paid to oocyte-derived secreted factors that act upon cumulus and granulosa cells. Also important for follicle development are somatic cell-derived secreted factors. This is illustrated by the ability of granulosa cell-derived Kit ligand (KITL) to promote primordial follicle activation, and the loss of follicle development that accompanies KITL gene disruption. This review summarises our current understanding of somatic cell factors during both preantral and antral follicle growth, involving not only signalling from granulosa cells to the oocyte, but also signalling between granulosa and theca cells. Principal granulosa cell-derived factors include activin, anti-Müllerian hormone (AMH), bone morphogenetic proteins (BMPs) and fibroblast growth factors (FGFs). Theca cells also secrete BMPs and FGFs. The interplay between these factors is equally important for follicle growth as the activity of oocyte-derived factors.


2005 ◽  
Vol 50 (23) ◽  
pp. 2665-2671 ◽  
Author(s):  
Lu Cuiling ◽  
Yang Wei ◽  
Hu Zhaoyuan ◽  
Liu Yixun

1996 ◽  
Vol 134 (5) ◽  
pp. 649-654 ◽  
Author(s):  
Grietje Dijkstra ◽  
Dirk G de Rooij ◽  
Frank H de Jong ◽  
Robert van den Hurk

Dijkstra G, de Rooij DG, de Jong FH, van den Hurk R. Effect of hypothyroidism on ovarian follicular development, granulosa cell proliferation and peripheral hormone levels in the prepubertal rat. Eur J Endocrinol 1996;134:649–54. ISSN 0804–4643 The aim of this study was to examine the effects of prepubertal hypothyroidism on ovarian development in rats. Therefore, from birth up to day 40 postpartum, rats were given 6-propyl-2-thiouracil (PTU) via the drinking water of mothers and pups. At ages ranging from 12 to 40 days, ovarian weights were measured and serum was collected to estimate thyrotrophin (TSH), folliclestimulating hormone (FSH) and inhibin levels. Two hours before sacrifice the animals received an injection of bromodeoxyuridine (BrdU) to estimate the proliferative activity of the follicular granulosa cells. Ovaries were fixed in Carnoy's fluid and follicle counts were performed on sections stained with anti-BrdU and with haematoxylin and eosin. The PTU treatment resulted in increased serum TSH levels, indicative of hypothyroidism, and markedly lower body and ovarian weights, whereas serum FSH and inhibin levels were hardly affected. At day 40, ovaries of PTU-treated animals contained relatively more secondary and less antral follicles, smaller non-atretic antral follicles and more atretic follicles when compared with untreated rats, while corpora lutea were absent. It is concluded that this disturbed folliculogenesis is due to inadequate thyroid hormone supply, which hampers the differentiation and not the proliferation of granulosa cells because diameters of antral follicles were significantly smaller whereas the BrdU-labelling index had not changed. Robert van den Hurk, Department of Functional Morphology, Faculty of Veterinary Medicine, PO Box 80.157, 3508 TD Utrecht, The Netherlands


2006 ◽  
Vol 73 (6) ◽  
pp. 737-744 ◽  
Author(s):  
Makoto Orisaka ◽  
Tetsuya Mizutani ◽  
Kimihisa Tajima ◽  
Sanae Orisaka ◽  
Ken-ichi Shukunami ◽  
...  

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