scholarly journals Atresia revisited: two basic patterns of atresia of bovine antral follicles

Reproduction ◽  
2001 ◽  
pp. 761-775 ◽  
Author(s):  
HF Irving-Rodgers ◽  
IL van Wezel ◽  
ML Mussard ◽  
JE Kinder ◽  
RJ Rodgers
Keyword(s):  
Basal Lamina ◽  
Granulosa Cells ◽  
Immunohistochemical Study ◽  
Steroid Hormone ◽  
Basal Layer ◽  
Follicle Development ◽  
Basal Cells ◽  
Apoptotic Bodies ◽  
Antral Follicles ◽  
Follicular Fluids

Our observations of bovine follicles indicated that the original histological classifications of atresia were inaccurate. A detailed histological, ultrastructural and immunohistochemical study of antral follicles from bovine ovaries collected from an abattoir and from animals whose large follicles had been monitored by ultrasonography was conducted to investigate this further. Nidogen and CD68 were immunolocalized to observe the follicular basal lamina and macrophages, respectively. In randomly collected ovaries, approximately one quarter of all antral follicles were undergoing antral atresia, as designated in this study. Antral atresia was characterized by early destruction of the layers of the membrana granulosa closest to the antrum, whereas the most basal cells remained intact. Numerous pyknotic nuclei were observed in the most antral layers and in the antrum close to the membrana granulosa. This is the classic description of atretic follicles and was observed at all sizes of follicle development and almost universally in large follicles (> 5 mm in diameter), including dominant follicles. Basal atretic follicles, as designated in this study, were almost as prevalent as the antral atretic follicles, and were characterized by initial destruction of the most basal layer of granulosa cells, whereas the cells in the most antral layers remained associated with each other and were predominantly healthy. Pyknotic nuclei and the nuclei of dying basal cells budded into apoptotic bodies were observed rarely. The basal lamina of basal atretic follicles was often breached by macrophages, which were phagocytosing dying basal granulosa cells. The theca was characterized by an increased deposition of collagen, and the cells were orientated randomly, rather than lying parallel to the membrana granulosa as in healthy follicles. Basal atresia occurred in small (< 5 mm in diameter) follicles only. Importantly, these basal atretic follicles were originally identified incorrectly in the literature. Thus, on the basis of the results of this study and another on the expression of steroidogenic enzymes in atretic follicles, it is suggested that the standard biochemical methods for measuring steroid hormone concentrations in follicular fluids to assess atresia should be re-evaluated.

Ultrastructure of the basal lamina of bovine ovarian follicles and its relationship to the membrana granulosa

Reproduction ◽  
2000 ◽  
pp. 221-228 ◽  
Author(s):  
HF Irving-Rodgers ◽  
RJ Rodgers
Keyword(s):  
Basal Lamina ◽  
Granulosa Cells ◽  
Light And Electron Microscopy ◽  
Single Layer ◽  
Antral Follicle ◽  
Basal Cells ◽  
Preantral Follicles ◽  
Antral Follicles ◽  
Cellular Processes ◽  
Innermost Layer

Different morphological phenotypes of follicular basal lamina and of membrana granulosa have been observed. Ten preantral follicles (< 0. 1 mm), and 17 healthy and six atretic antral follicles (0.5-12 mm in diameter) were processed for light and electron microscopy to investigate the relationship the between follicular basal lamina and membrana granulosa. Within each antral follicle, the shape of the basal cells of the membrana granulosa was uniform, and either rounded or columnar. There were equal proportions of follicles </= 4 mm in diameter with columnar basal cells and with rounded basal cells. Larger follicles had only rounded basal cells. Conventional basal laminae of a single layer adjacent to the basal granulosa cells were observed in healthy follicles at the preantral and antral stages. However, at the preantral stage, the conventional types of basal lamina were enlarged or even partially laminated. A second type of basal lamina, described as 'loopy', occurred in about half the preantral follicles and in half the antral follicles </= 4 mm diameter. 'Loopy' basal laminae were not observed in larger follicles. 'Loopy' basal laminae were composed of basal laminae aligning the basal surface of basal granulosa cells, but with additional layers or loops often branching from the innermost layer. Each loop was usually < 1 microm long and had vesicles (20-30 nm) attached to the inner aspect. Basal cellular processes were also common, and vesicles could be seen budding off from these processes. In antral follicles, conventional basal laminae occurred in follicles with rounded basal granulosa cells. Other follicles with columnar cells, and atretic follicles, had the 'loopy' basal lamina phenotype. Thus, follicles have different basal laminae that relate to the morphology of the membrana granulosa.

scholarly journals Morphological classification of bovine ovarian follicles

Reproduction ◽  
2010 ◽  
Vol 139 (2) ◽  
pp. 309-318 ◽  
Author(s):  
R J Rodgers ◽  
H F Irving-Rodgers
Keyword(s):  
Basal Lamina ◽  
Granulosa Cells ◽  
Follicular Development ◽  
Basal Cells ◽  
Morphological Classification ◽  
Primordial Follicles ◽  
Antral Follicles ◽  
Different Types ◽  
Biological Differences

Follicle classification is an important aid to the understanding of follicular development and atresia. Some bovine primordial follicles have the classical primordial shape, but ellipsoidal shaped follicles with some cuboidal granulosa cells at the poles are far more common. Preantral follicles have one of two basal lamina phenotypes, either a single aligned layer or one with additional layers. In antral follicles <5 mm diameter, half of the healthy follicles have columnar shaped basal granulosa cells and additional layers of basal lamina, which appear as loops in cross section (‘loopy’). The remainder have aligned single-layered follicular basal laminas with rounded basal cells, and contain better quality oocytes than the loopy/columnar follicles. In sizes >5 mm, only aligned/rounded phenotypes are present. Dominant and subordinate follicles can be identified by ultrasound and/or histological examination of pairs of ovaries. Atretic follicles <5 mm are either basal atretic or antral atretic, named on the basis of the location in the membrana granulosa where cells die first. Basal atretic follicles have considerable biological differences to antral atretic follicles. In follicles >5 mm, only antral atresia is observed. The concentrations of follicular fluid steroid hormones can be used to classify atresia and distinguish some of the different types of atresia; however, this method is unlikely to identify follicles early in atresia, and hence misclassify them as healthy. Other biochemical and histological methods can be used, but since cell death is a part of normal homoeostatis, deciding when a follicle has entered atresia remains somewhat subjective.

scholarly journals Composition and morphology of the follicular basal lamina during atresia of bovine antral follicles

Reproduction ◽  
2002 ◽  
pp. 97-106 ◽  
Author(s):  
HF Irving-Rodgers ◽  
ML Mussard ◽  
JE Kinder ◽  
RJ Rodgers
Keyword(s):  
Basal Lamina ◽  
Granulosa Cells ◽  
Cell Shape ◽  
Type Iv Collagen ◽  
Basal Cells ◽  
Follicle Growth ◽  
Electron Microscopic ◽  
Antral Follicles ◽  
Type Iv ◽  
Follicle Diameter

The fate of the follicular basal lamina during atresia was investigated using bovine follicles, in which different follicle phenotypes have been observed. These phenotypes include: healthy follicles with rounded basal granulosa cells with an aligned basal lamina or follicles with columnar basal granulosa cells with a basal lamina of many loops (loopy), and atretic follicles in which either the antral granulosa cells (antral atresia) or the basal cells (basal atresia) die first. Loopy lamina and basal atresia occur only in small antral follicles < 5 mm in diameter. Follicles were collected from cattle of unknown reproductive history and processed for immunohistochemistry and electron microscopy, and from animals in which follicle growth had been monitored by daily measurements of follicle diameter by ultrasonography. Electron microscopic observations of dominant follicles during the growth phase, plateau and regression showed that the basal lamina was still visible and intact upon atresia. These follicles had a conventional aligned basal lamina, which they retained, except for some degree of folding, as they progressed into antral atresia. In small follicles (2-5 mm in diameter), the basal cell shape (rounded or columnar) and appearance of the basal lamina (aligned or of many loops) did not appear to be related to the type of atresia. On atresia the follicular basal laminae retained immunoreactive laminin alpha1 and beta2, type IV collagen alpha1 and nidogen. Laminin alpha2, which may come from the theca, was present in the follicular basal lamina of only 22% of healthy follicles, but was expressed very commonly in 71% of the atretic follicles. Laminin alpha2 expression was found in both phenotypes of healthy follicles, antral and basal atretic follicles, and follicles with aligned or loopy basal laminae. It is concluded that the basal lamina is not degraded upon atresia, but does undergo a variety of other changes.

Insulin-like growth factor binding proteins in follicular fluid from morphologically distinct healthy and atretic bovine antral follicles

2003 ◽  
Vol 15 (4) ◽  
pp. 241 ◽  
Author(s):  
H. F. Irving-Rodgers ◽  
K. D. Catanzariti ◽  
M. Master ◽  
P. A. Grant ◽  
P. C. Owens ◽  
...  
Keyword(s):  
Growth Factor ◽  
Basal Lamina ◽  
Granulosa Cells ◽  
Follicular Fluid ◽  
Binding Proteins ◽  
Basal Layer ◽  
Insulin Like Growth Factor ◽  
Basal Cells ◽  
Factor Binding ◽  
Different Types

In bovine follicles 2–5 mm in diameter, two morphologically distinct types of healthy follicles and two types of atretic follicles have been described recently. Healthy follicles either have columnar basal granulosa cells with follicular basal lamina composed of many layers or ‘loops’ or they have rounded basal cells with a conventional single-layered, aligned follicular basal lamina. In atretic follicles, cell death either commences at the basal layer and progresses to the antrum (basal atresia) with macrophage penetration of the membrana granulosa or death progresses from the antrum in a basal direction (antral atresia). Little is known about how these different phenotypes develop. To determine whether insulin-like growth factor binding protein (IGFBP) levels in follicular fluid differ between these different types of follicles, we measured IGFBP levels in fluids from these follicles. A total of 61 follicles were assessed by light microscopy and characterized by morphological analysis as either healthy, with columnar or rounded basal granulosa cells, or as undergoing antral or basal atresia. The IGFBP concentration in the follicular fluid of individual follicles from the four groups (n = 12–20 per group) was identified by Western ligand blots using 125I-insulin-like growth factor (IGF)-II as a probe. Insulin-like growth factor binding proteins 2, 3 (44 and 40 kDa), 4 (glycosylated and non-glycosylated) and 5 were observed. The levels (per volume of fluid) of IGFBPs 2, 4 and 5 were greater in atretic follicles than in healthy follicles. However, there were no statistical differences in levels of each IGFBP between either the two types of healthy follicle or between the two types of atretic follicles. Thus, IGFBP levels are not related to the different types of healthy or atretic follicles.

scholarly journals Insulin-like growth factor 2 is produced by antral follicles and promotes preantral follicle development in macaques

2020 ◽  
Author(s):  
Olena Y Tkachenko ◽  
Shally Wolf ◽  
Maralee S Lawson ◽  
Alison Y Ting ◽  
Jhenifer K Rodrigues ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Granulosa Cell ◽  
Steroid Hormone ◽  
Follicle Development ◽  
Hormone Regulation ◽  
Preantral Follicle ◽  
Paracrine Factor ◽  
Preantral Follicles ◽  
Antral Follicles ◽  
And Function

Abstract Insulin-like growth factors (IGFs) are known for their involvement in endocrine and paracrine regulation of ovarian function. While IGF2 is the predominant circulating and intra-ovarian form of IGFs in primate species, the stage-specific follicular expression, action and regulation of IGF2 are not well defined. Therefore, experiments were conducted to investigate the follicular IGF production in response to steroid hormone regulation and the direct IGF actions on follicular development and function in vitro. Preantral follicles were isolated from rhesus macaque ovaries and cultured to the antral stage in media supplemented with follicle-stimulating hormone and insulin. Follicles were randomly assigned to treatment groups: (a) control, (b) trilostane (a steroid synthesis inhibitor), (c) trilostane + estradiol, (d) trilostane + progesterone, and (e) trilostane + dihydrotestosterone. Media was analyzed for IGF concentrations, which were correlated to follicle growth. Follicles produced IGF2, but not IGF1, at the antral stage. Steroid depletion decreased, while steroid replacement increased, IGF2 production by antral follicles. Media IGF2 levels correlated positively with antral follicle diameters. Macaque preantral follicles and granulosa cells were subsequently cultured without (control) and with recombinant human IGF2 supplementation. Follicle survival, growth and paracrine factor production, as well as granulosa cell proliferation and gonadotropin receptor gene expression, were assessed. IGF2 addition increased follicle survival rates, diameters and inhibin B production, as well as granulosa cell proliferation. These data demonstrate that IGF2 produced by antral follicles, in response to steroid hormone regulation, could act as a paracrine factor that positively impacts preantral follicle development and function in primates.

143. DIFFERENCES IN GENE EXPRESSION BETWEEN APICAL AND BASAL CELLS OF THE MEMBRANA GRANULOSA

2010 ◽  
Vol 22 (9) ◽  
pp. 61
Author(s):  
H. F. Irving-Rodgers ◽  
S. T. Lee ◽  
N. Hatzirodos ◽  
K. Hummitzsch ◽  
T. R. Sullivan ◽  
...  
Keyword(s):  
Basal Lamina ◽  
Granulosa Cells ◽  
Single Layer ◽  
Cumulus Cells ◽  
Endocrine Function ◽  
Follicular Epithelium ◽  
Basal Cells ◽  
Expression Of Genes ◽  
Apical Cells ◽  
Follicle Maturation

Granulosa cells constitute the ovarian follicular epithelium which at the beginning of folliculogenesis forms a single layer of flattened cells. As the follicle matures the cells acquire a cuboidal morphology, proliferate and differentiate into the cumulus cells surrounding the oocyte, and the mural granulosa cells forming the inner layer of the follicle (the membrana granulosa). Mural granulosa cells may further differ in their functionality depending on whether they are situated apically or basally within the stratified membrana granulosa. Late in folliculogenesis granulosa cells develop the ability to produce oestradiol, and also a specialised extracellular matrix (focimatrix) which is more abundant between apical cells. In order to investigate possible differences between granulosa cells, the expression of genes for oestradiol synthesis (CYP11A1, CYP19A1), focimatrix components (LAMB2, COL4A1, HSPG2), FSH and LH receptors, and cell cycle genes (CCND2, CCNE1, CCNE2, CDKN1B, CDKN2D) were examined in apical and basal granulosa cells from large healthy bovine follicles [n = 18, 14.3 ± 0.3 mm (mean + SEM)] using quantitative RT-PCR. Apical granulosa cells were collected by flushing the follicle with balanced salt solution. The remaining cells were detached from the follicular basal lamina by gently scraping; these are the basal granulosa cells. This collection method resulted in equivalent cell yields of apical and basal cells. Expression for all genes was significantly higher in basal cells in comparison to apical cells (P < 0.05), except for the cycle genes CCND2 and CDKN2D, which did not differ between cell populations. These results suggest that functional heterogeneity exists within the membrana granulosa. How differences between apical and basal cells are established is unknown but may be due to the proximity of the basal cells to the follicular basal lamina. The relevance of this aspect of follicle maturation to the endocrine function of granulosa cells has yet to be determined.

scholarly journals Glial-derived neurotrophic factor promotes ovarian primordial follicle development and cell–cell interactions during folliculogenesis

Reproduction ◽  
2008 ◽  
Vol 135 (5) ◽  
pp. 671-682 ◽  
Author(s):  
Gretchen Dole ◽  
Eric E Nilsson ◽  
Michael K Skinner
Keyword(s):  
Microarray Analysis ◽  
Granulosa Cells ◽  
Neurotrophic Factor ◽  
Primordial Follicle ◽  
Cell Interactions ◽  
Follicle Development ◽  
Antral Follicles ◽  
Theca Cells ◽  
Oocyte Cytoplasm ◽  
Cell Cell

Female fertility is determined in part by the size and development of the primordial follicle pool. The current study investigates the role of glial cell-line-derived neurotrophic factor (GDNF) in the regulation of primordial follicle development in the ovary. Ovaries from 4-day-old female rat pups were maintained in organ culture for 10 days in the absence (control) or presence of GDNF or kit ligand (KL)/stem cell factor. Ovaries treated with GDNF contained a significant increase in developing follicles, similar to that observed with KL treatment previously shown to promote follicle development. The actions of GDNF on the ovarian transcriptome were investigated with a microarray analysis. Immunohistochemical studies demonstrated that GDNF is localized to oocyte cytoplasm in follicles of all developmental stages, as well as to cumulus granulosa cells and theca cells in antral follicles. GDNF receptor α1 (GFRα1) staining was localized to oocyte cytoplasm of primordial and primary follicles, and at reduced levels in the oocytes of antral follicles. GFRα1 was present in mural granulosa cells of antral follicles, theca cells, and ovarian surface epithelium. The localization studies were confirmed with molecular analysis. Microarray analysis was used to identify changes in the ovarian transcriptome and further elucidate the signaling network regulating early follicle development. Observations indicate that GDNF promotes primordial follicle development and mediates autocrine and paracrine cell–cell interactions required during folliculogenesis. In contrast to the testis, ovarian GDNF is predominantly produced by germ cells (oocytes) rather than somatic cells.

scholarly journals Localization of follicle regulatory protein in the porcine ovary.

1988 ◽  
Vol 36 (6) ◽  
pp. 589-595 ◽  
Author(s):  
K Fujimori ◽  
K E Rodgers ◽  
R M Nakamura ◽  
E Katt ◽  
D L Yanagihara ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Basal Lamina ◽  
Granulosa Cells ◽  
Polyclonal Antibody ◽  
Regulatory Protein ◽  
Large Cell ◽  
Positive Staining ◽  
Primordial Follicles ◽  
Antral Follicles ◽  
Antibody Preparations

The granulosa cell secretes a protein (follicle regulatory protein: FRP) that affects the responsiveness of other follicles to gonadotropin stimulation. This protein was purified, partially characterized, and rabbit antisera as well as monoclonal antibodies were prepared against FRP. Fixed sections of porcine ovaries were prepared on slides and then incubated with the monoclonal antibody or polyclonal antisera and then incubated with either biotinylated mouse IgM or rabbit IgG antisera, respectively. These sections were then incubated with avidin conjugated to horseradish peroxidase, followed by substrate. Staining with both the monoclonal antibody and the antisera was present in the cytoplasm of granulosa cells of small- or medium-sized antral follicles. Staining distribution was localized preferentially to cells near the basal lamina; the antral granulosa cells of viable follicles did not stain. Neither primordial follicles nor pre-antral follicles (less than 300 microns in diameter) showed any positive staining. Thecal cells were not stained in follicles less than 5 mm in diameter, whereas some large follicles (greater than 5 mm) contained staining in the theca. In the latter, specific granulosa staining was only weakly positive with the polyclonal antibody and negative with the monoclonal antibody. Atretic follicles contained significant staining of all epithelial cells adjacent to the basal lamina by both the monoclonal and polyclonal antibody preparations. Staining of the luteal ovary by the monoclonal antibody was limited to the large luteal cells. These findings suggest that FRP is produced by the granulosa cells of porcine follicles at the stage of maturation corresponding to 0.5 mm in diameter. As the viable follicle increases in size, production of FRP in the granulosa is reduced below the detectable level when the follicle exceeds 5 mm in diameter. The main source of FRP during the luteal phase is the large cell of the corpus luteum.

scholarly journals Role of Jagged1-mediated Notch Signaling Activation in the Differentiation and Stratification of the Human Limbal Epithelium

Cells ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1945
Author(s):  
Sheyla González ◽  
Maximilian Halabi ◽  
David Ju ◽  
Matthew Tsai ◽  
Sophie X. Deng
Keyword(s):  
Notch Signaling ◽  
Progenitor Cell ◽  
Basal Layer ◽  
Notch Signaling Pathway ◽  
Basal Cells ◽  
Proliferation Markers ◽  
Limbal Epithelium ◽  
Asymmetric Divisions ◽  
Signaling Activation

The Notch signaling pathway plays a key role in proliferation and differentiation. We investigated the effect of Jagged 1 (Jag1)-mediated Notch signaling activation in the human limbal stem/progenitor cell (LSC) population and the stratification of the limbal epithelium in vitro. After Notch signaling activation, there was a reduction in the amount of the stem/progenitor cell population, epithelial stratification, and expression of proliferation markers. There was also an increase of the corneal epithelial differentiation. In the presence of Jag1, asymmetric divisions were decreased, and the expression pattern of the polarity protein Par3, normally present at the apical-lateral membrane of basal cells, was dispersed in the cells. We propose a mechanism in which Notch activation by Jag1 decreases p63 expression at the basal layer, which in turn reduces stratification by decreasing the number of asymmetric divisions and increases differentiation.

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