scholarly journals Ovarian follicle development in the laying hen is accompanied by divergent changes in inhibin A, inhibin B, activin A and follistatin production in granulosa and theca layers

2003 ◽  
Vol 177 (1) ◽  
pp. 45-55 ◽  
Author(s):  
TM Lovell ◽  
RT Gladwell ◽  
NP Groome ◽  
PG Knight
Keyword(s):  
Functional Role ◽  
Ovarian Follicle ◽  
Fold Increase ◽  
Activin A ◽  
Inhibin B ◽  
Follicle Development ◽  
Inhibin A ◽  
Ovarian Follicle Development ◽  
Tissue Extracts

To study the potential involvement of inhibin A (inhA), inhibin B (inhB), activin A (actA) and follistatin (FS) in the recruitment of follicles into the preovulatory hierarchy, growing follicles (ranging from 1 mm to the largest designated F1) and the three most recent postovulatory follicles (POFs) were recovered from laying hens (n=11). With the exception of <4 mm follicles and POFs, follicle walls were dissected into separate granulosa (G) and theca (T) layers before extraction. Contents of inhA, inhB, actA and FS in tissue extracts were assayed using specific two-site ELISAs and results are expressed per mg DNA. InhB content of both G and T followed a similar developmental pattern, although the content was >4-fold higher in G than in T at all stages. InhB content was very low in follicles <4 mm but increased ~50-fold (P<0.0001) to peak in 7-9 mm follicles, before falling steadily as follicles entered and moved up the follicular hierarchy (40-fold; 8 mm vs F2). In stark contrast, inhA remained very low in prehierarchical follicles (< or =9 mm) but then increased progressively as follicles moved up the preovulatory hierarchy to peak in F1 (approximately 100-fold increase; P<0.0001); In F1 >97% of inhA was confined to the G layer whereas in 5-9 mm follicles inhA was only detected in the T layer. Both inhA and inhB contents of POFs were significantly reduced compared with F1. Follicular actA was mainly confined to the T layer although detectable levels were present in G from 9 mm; actA was low between 1 and 9 mm but increased sharply as follicles entered the preovulatory hierarchy (approximately 6-fold higher in F4; P<0.0001); levels then fell approximately 2-fold as the follicle progressed to F1. Like actA, FS predominated in the T although significant amounts were also present in the G of prehierarchical follicles (4-9 mm), in contrast to actA, which was absent from the G. The FS content of T rose approximately 3-fold from 6 mm to a plateau which was sustained until F1. In contrast, the FS content of G was greatest in prehierarchical follicles and fell approximately 4-fold in F4-F1 follicles. ActA and FS contents of POFs were reduced compared with F1. In vitro studies on follicle wall explants confirmed the striking divergence in the secretion of inhA and inhB during follicle development. These findings of marked stage-dependent differences in the expression of inhA, inhB, actA and FS proteins imply a significant functional role for these peptides in the recruitment and ordered progression of follicles within the avian ovary.

scholarly journals Bovine follicle development is associated with divergent changes in activin-A, inhibin-A and follistatin and the relative abundance of different follistatin isoforms in follicular fluid

2006 ◽  
Vol 188 (2) ◽  
pp. 215-225 ◽  
Author(s):  
Claire Glister ◽  
Nigel P Groome ◽  
Philip G Knight
Keyword(s):  
Relative Abundance ◽  
Follicular Fluid ◽  
Fold Increase ◽  
Activin A ◽  
Major Influence ◽  
Follicle Development ◽  
Follicle Growth ◽  
Inhibin A ◽  
Follicle Selection

The aim was to determine whether follicle growth in cattle is accompanied by changes in levels of inhibin-A (inh-A), activin-A (act-A) and different Mr isoforms of follistatin (FS) in bovine follicular fluid (bFF), reflecting differential roles of these proteins during folliculogenesis. Follicles (n=146) from 2–20 mm diameter were dissected from ovaries of ~40 cattle. Immunoassays were used to measure total FS, act-A, inh-A, oestradiol (E) and progesterone (P) levels; immunoblotting was used to quantify the relative abundance of different FS isoforms. Follicle growth from 2–6 mm was associated with a 6-fold increase in inh-A and 30-fold increase in act-A; FS remained uniformly high from 2–10 mm. From 6–2 mm, inh-A remained high while act-A and FS fell 3-fold and 2-fold, respectively. Act-A/FS ratio increased 20-fold from 2–6 mm before falling slightly through to 20 mm. Act-A/inh-A ratio increased 6-fold from 2–6 mm before falling 2-fold from 6 to 17–20 mm. These findings imply a marked increase in relative activin ‘tone’ around the stage at which dominant follicle selection occurs. When larger follicles (13–20 mm) were subdivided according to E/P ratio, those with high ( > 5) E/P ratio had lower (2-fold; P < 0.001) levels of inh-A and act-A in comparison to follicles with low ( < 5) E/P ratio, but there were no significant differences in FS, act-A/inh-A ratio or act-A/FS ratio. Thus follicle size, but not oestrogenic status, has a major influence on the intrafollicular balance between act-A and its opposing factors, inh-A and FS. Six FS isoforms were detected in bFF (apparent Mr: 65, 41, 37, 35, 33 and 31 kDa) averaging 6, 13, 24, 26, 13 and 17% respectively of total FS. During growth from 2–20 mm the proportion of total FS represented by 65, 41 and 37 kDa isoforms increased ~2-fold while the proportion represented by the 33 and 31 kDa isoforms decreased by 3-fold and 1.6-fold, respectively. Treatment of bovine granulosa cells in vitro with FSH and IGF alone or in combination increased total FS secretion up to 12-fold but did not affect the relative abundance of the five different FS isoforms detected. While the functional significance of the intriguing shift in FS isoform abundance in bFF during follicle development remains to be established, we have shown that a marked increase in intrafollicular activin ‘tone’ accompanies bovine follicle growth from 3–6 mm, corresponding to the stage at which the FSH-dependent follicle selection mechanism operates in this species.

scholarly journals Interpenetrating fibrin–alginate matrices for in vitro ovarian follicle development

Biomaterials ◽  
2009 ◽  
Vol 30 (29) ◽  
pp. 5476-5485 ◽  
Author(s):  
Ariella Shikanov ◽  
Min Xu ◽  
Teresa K. Woodruff ◽  
Lonnie D. Shea
Keyword(s):  
Ovarian Follicle ◽  
Follicle Development ◽  
Ovarian Follicle Development ◽  
Alginate Matrices

scholarly journals Involvement of miRNAs in equine follicle development

Reproduction ◽  
2013 ◽  
Vol 146 (3) ◽  
pp. 273-282 ◽  
Author(s):  
S N Schauer ◽  
S D Sontakke ◽  
E D Watson ◽  
C L Esteves ◽  
F X Donadeu
Keyword(s):  
Cell Survival ◽  
Granulosa Cells ◽  
Follicular Fluid ◽  
Ovarian Follicle ◽  
Follicle Development ◽  
Previous Evidence ◽  
Ovarian Follicle Development ◽  
Fluid Levels ◽  
Follicle Selection

Previous evidence fromin vitrostudies suggests specific roles for a subset of miRNAs, including miR-21, miR-23a, miR-145, miR-503, miR-224, miR-383, miR-378, miR-132, and miR-212, in regulating ovarian follicle development. The objective of this study was to determine changes in the levels of these miRNAs in relation to follicle selection, maturation, and ovulation in the monovular equine ovary. In Experiment 1, follicular fluid was aspirated during ovulatory cycles from the dominant (DO) and largest subordinate (S) follicles of an ovulatory wave and the dominant (DA) follicle of a mid-cycle anovulatory wave (n=6 mares). Follicular fluid levels of progesterone and estradiol were lower (P<0.01) in S follicles than in DO follicles, whereas mean levels of IGF1 were lower (P<0.01) in S and DA follicles than in DO follicles. Relative to DO and DA follicles, S follicles had higher (P≤0.01) follicular fluid levels of miR-145 and miR-378. In Experiment 2, follicular fluid and granulosa cells were aspirated from dominant follicles before (DO) and 24 h after (L) administration of an ovulatory dose of hCG (n=5 mares/group). Relative to DO follicles, L follicles had higher follicular fluid levels of progesterone (P=0.05) and lower granulosa cell levels ofCYP19A1andLHCGR(P<0.005). Levels of miR-21, miR-132, miR-212, and miR-224 were increased (P<0.05) in L follicles; this was associated with reduced expression of the putative miRNA targets,PTEN,RASA1, andSMAD4. These novel results may indicate a physiological involvement of miR-21, miR-145, miR-224, miR-378, miR-132, and miR-212 in the regulation of cell survival, steroidogenesis, and differentiation during follicle selection and ovulation in the monovular ovary.

scholarly journals Correction to: Synergy of Paracrine Signaling During Early-Stage Mouse Ovarian Follicle Development In Vitro

2018 ◽  
Vol 11 (6) ◽  
pp. 537-537
Author(s):  
Hong Zhou ◽  
Joseph T. Decker ◽  
Melissa M. Lemke ◽  
Claire E. Tomaszewski ◽  
Lonnie D. Shea ◽  
...  
Keyword(s):  
Early Stage ◽  
Ovarian Follicle ◽  
Follicle Development ◽  
Paracrine Signaling ◽  
Ovarian Follicle Development ◽  
Development In Vitro

Activin promotes ovarian follicle development in vitro.

Endocrinology ◽  
1995 ◽  
Vol 136 (3) ◽  
pp. 849-856 ◽  
Author(s):  
R Li ◽  
D M Phillips ◽  
J P Mather
Keyword(s):  
Ovarian Follicle ◽  
Follicle Development ◽  
Ovarian Follicle Development ◽  
Development In Vitro

123. ACTIVIN A AND OVARIAN FOLLICLE DEVELOPMENT

2009 ◽  
Vol 21 (9) ◽  
pp. 42
Author(s):  
D. A. Cossigny (Rosairo) ◽  
J. K. Findlay ◽  
A. E. Drummond
Keyword(s):  
Ovarian Follicle ◽  
Combined Treatment ◽  
Rna Extraction ◽  
Activin A ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Follicle Development ◽  
Preantral Follicle ◽  
Primary Follicle ◽  
Preantral Follicles ◽  
Ovarian Follicle Development

A significant developmental stage in ovarian folliculogenesis is the acquisition of gonadotropin sensitivity by ovarian follicles. Activin has previously been suggested to be involved in the responsiveness of granulosa cells to FSH (1). Therefore, the role of activin was investigated using a ‘physiological’ culture system to determine if pathways exist to transduce activin signals within the postnatal rat ovary. Organ cultures with day 4 whole ovaries were employed in order to assess the potential impact of Activin A on follicle growth and transition from the primordial through to the primary and later preantral stages of development. Ovaries were isolated and cultured for 10 days with the addition of supplemented DMEM/Hams F-12 media (2)and either FSH (100ng/ml), Activin A (50ng/ml), or a combination of the two. Media and treatments were refreshed every alternate day. At the end of the culture period, ovaries were fixed and sectioned, or placed immediately into Ultraspec for RNA extraction for future real-time PCR. Sections were used for morphological assessment and ovarian follicle counting of primordial, primary and preantral follicles. An evaluation of atresia by the detection of apoptotic cells was undertaken using terminal deoxynucleotidyl transferase (TdT) mediated dUTP-biotin nick-end labeling (TUNEL). Primary follicle numbers increased significantly (P<0.05) in the combined treatment group whereas, preantral follicle numbers increased significantly (P<0.0001) when treated with Activin A alone. This is consistent with a morphological appraisal of atresia where a decrease in atresia was found in primordial and primary follicles, supporting the primary follicle development data and Activin A treatment alone resulted in more healthy primary and preantral follicles than atretic ones. Therefore, a stimulatory role for Activin A both in the presence of FSH (primary follicle development) or alone (preantral follicle development) has resulted in more follicles making the transition from the primordial to primary stages, as well as to the later preantral stages.

scholarly journals Synergy of Paracrine Signaling During Early-Stage Mouse Ovarian Follicle Development In Vitro

2018 ◽  
Vol 11 (5) ◽  
pp. 435-450 ◽  
Author(s):  
Hong Zhou ◽  
Joseph T. Decker ◽  
Melissa M. Lemke ◽  
Claire E. Tomaszweski ◽  
Lonnie D. Shea ◽  
...  
Keyword(s):  
Early Stage ◽  
Ovarian Follicle ◽  
Follicle Development ◽  
Paracrine Signaling ◽  
Ovarian Follicle Development ◽  
Development In Vitro

scholarly journals Initial and Cyclic Recruitment of Ovarian Follicles*

2000 ◽  
Vol 21 (2) ◽  
pp. 200-214 ◽  
Author(s):  
Elizabeth A. McGee ◽  
Aaron J. W. Hsueh
Keyword(s):  
Ovarian Follicle ◽  
Ovarian Follicles ◽  
Follicle Development ◽  
Ovarian Follicle Development ◽  
Branching Points ◽  
Reproductive Techniques ◽  
Recruitment And Selection ◽  
Cyclic Recruitment

Abstract Mammalian ovaries consist of follicles as basic functional units. The total number of ovarian follicles is determined early in life, and the depletion of this pool leads to reproductive senescence. Each follicle develops to either ovulate or, more likely, to undergo degeneration. The dynamics of ovarian follicle development have interested endocrinologists and developmental biologists for many years. With the advent of assisted reproductive techniques in humans, the possibility of regulating follicle development in vivo and in vitro has gained clinical relevance. In this review, we focus upon key branching points during the development of ovarian follicles as well as factors involved in determining the eventual destiny of individual follicles. We discuss inconsistencies in the literature regarding the definitions of follicle recruitment and selection and propose to name the two major steps of follicle development as initial and cyclic recruitment, respectively. Because some of these disparities have arisen due to differences in the animal systems studied, we also compare the development of the ovarian follicles of both humans and rats. We also review the status of knowledge of several puzzling clinical issues that may provide important clues toward unlocking the mechanisms of follicle development.

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