Ultrastructural observations of previtellogenic ovarian follicles of dove

Zygote ◽  
2004 ◽  
Vol 12 (4) ◽  
pp. 285-292 ◽  
Author(s):  
Otilia Zarnescu
Keyword(s):  
Electron Microscopy ◽  
Granulosa Cells ◽  
Ovarian Follicle ◽  
Complex Structure ◽  
Cortical Region ◽  
Multivesicular Bodies ◽  
Coated Pits ◽  
Zona Radiata ◽  
Theca Externa ◽  
Theca Interna

Dove ovarian follicle is a complex structure composed of oocyte surrounded by a somatic compartment consisting of theca externa, theca interna and granulosa. The structure of ovarian follicle (1 and 2 mm) of dove was studied by electron microscopy. The granulosa was pseudostratified in the 1-mm-diameter follicles and stratified with two or three irregular rows of cells in the 2-mm-diameter follicles. In the larger follicle indentations between oocyte and granulosa cells become more numerous and the microvilli of granulosa cell elongated to form a zona radiata with similarly elongated oocyte microvilli. Lining bodies were present at the tips of granulosa microvilli and in the cortical region of the oocyte. In the oocyte cortex were observed coated pits, coated vesicles, dense tubules, multivesicular bodies and primordial yolk spheres. Primordial yolk spheres may contain lining bodies and were observed fused with dense tubules and multivesicular bodies or associated with smooth cisternae.

scholarly journals Localization of binding sites for IGF-I, insulin and GH in the sow ovary

1999 ◽  
Vol 163 (2) ◽  
pp. 363-372 ◽  
Author(s):  
H Quesnel
Keyword(s):  
Granulosa Cells ◽  
Stromal Cells ◽  
Binding Sites ◽  
Binding Proteins ◽  
Cell Function ◽  
Type I ◽  
Thecal Cells ◽  
Igf I ◽  
Theca Externa ◽  
Theca Interna

Binding sites for IGF-I, insulin, and GH were localized by in situ binding of (125)I-labelled hormones to the different compartments of the sow ovary. Binding sites for IGF-I were detected in oocytes, granulosa and thecal cells of healthy and atretic follicles as well as in the antrum and the stroma. Competition of (125)I-labelled IGF-I with IGF-I, insulin and an analogue of IGF-I (Long R(3)IGF-I), which allowed discrimination between binding to binding proteins from binding to type-I receptors, suggested that type-I receptors were present in granulosa cells of healthy follicles, whilst binding in other compartments was mainly due to binding proteins. Binding of insulin was revealed in oocytes, granulosa and theca interna cells of healthy preantral and antral follicles, and, to a lesser extent, in theca externa and stromal cells, and was still observed in granulosa cells of atretic follicles. Labelling with (125)I-labelled bovine GH was demonstrated in oocytes, granulosa cells, theca interna cells, and, although less intense, in theca externa and stromal cells. It disappeared in granulosa cells during atresia. Binding sites for GH were detected at all follicular stages, from preantral to preovulatory stages, but the intensity of labelling in granulosa cells was more intense in preantral than in large follicles. These data support the participation of insulin, GH and IGF-I in oocyte maturation, follicular growth and stromal cell function in swine.

scholarly journals Structure-Function Relationships in the Wall of the Ovarian Follicle

1981 ◽  
Vol 34 (4) ◽  
pp. 379 ◽  
Author(s):  
JD O'Shea
Keyword(s):  
Cell Function ◽  
Current Knowledge ◽  
Ovarian Follicle ◽  
Follicular Epithelium ◽  
Future Research ◽  
Seminiferous Tubules ◽  
Steroidogenic Cell ◽  
Theca Externa ◽  
Theca Interna ◽  
Follicular Epithelial

This paper reviews current knowledge of the light and electron microscopic structure of the three layers of the mammalian follicular wall-follicular epithelium (membrana granulosa), theca interna and theca externa-and discusses correlations between structure and function. The ultrastructure of follicular epithelial cells in growing follicles emphasizes their protein synthetic and secretory functions; features suggestive of a major steroidogenic function appear only at later stages. Regional differences in follicular epithelial cell function are probably important, although structurally these cells are relatively homogeneous. Structural diversity is more marked in the thecal layers : differentiation in the theca interna is towards fibrocytic and steroidogenic cell types, while that in the theca externa is towards fibrocytic and myoid types. Adherens and gap junctions are present between cells in all layers; however, tight (occludens) junctions have not been convincingly demonstrated between the cells in any of the three layers. Blood and lymph vessels are confined to the thecal layers. However, follicles possess no structural barrier comparable to that associated with the 'blood-testis barrier', and show a correspondingly greater permeability to large molecules than seminiferous tubules. Interactions between the layers of the follicular wall have not yet been intensively investigated, but are likely to play an important role in follicular function. To date, the best-documented interaction between layers is that described in the 'two-cell hypothesis' of oestrogen production. Some potentially useful directions for future research are proposed.

scholarly journals Scanning Electron Microscopy of Granulosa Cells in the Porcine Ovarian Follicle

1982 ◽  
Vol 53 (12) ◽  
pp. 831-837
Author(s):  
Hajime MIYAMOTO ◽  
Ryosuke FURUBAYASHI ◽  
Takao TANII ◽  
Takehiko ISHIBASHI
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Granulosa Cells ◽  
Ovarian Follicle ◽  
Scanning Electron

Histological description of aceh cattle ovary cryopreserved by various cryoprotectants

2018 ◽  
Author(s):  
Roslizawaty Roslizawaty ◽  
Syafruddin Syafruddin ◽  
Tongku Nizwan Siregar ◽  
Azrin . ◽  
Zuhrawati Zuhrawati ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Liquid Nitrogen ◽  
Histological Examination ◽  
Zona Pellucida ◽  
Ovarian Follicle ◽  
Cumulus Oophorus ◽  
Theca Externa ◽  
Theca Interna ◽  
Phosphate Buffered Saline ◽  
Better Than

This research aimed to determine Aceh cattle ovarian follicle morphological integrity after vitrified by various cryoprotectants. Cryoprotectants used in this research were 30% ethylene glycol (EG), 30% dimethyl suphocide (DMSO), and combination of 15% EG + 15% DMSO. Prior to vitrification process, ovaries were cleansed by phosphate buffered saline (PBS) and then cut into ±1 mm³. Ovaries were consecutively submerged into the following liquid for 5 minutes each: PBS+ 0.25 M sucrose; PBS+ 0.5 M sucrose; PBS+ 0.5 M sucrose + 10% cryoprotectants; and PBS+ 0.5 M sucrose + 30% cryoprotectants. Then, ovaries were packed into straws with ±7 cm in length and ± 6 mm in diameter. Before kept in liquid nitrogen, ovaries were first exposed to nitrogen fume for 10 second. After being stored for 1 day, the ovaries were proceed for histological examination. The result showed that Aceh cattle ovarian follicle after vitrification using 30% EG yields the best morphological integrity. Cumulus oophorus, zona pellucida, granulose cell arrangement, theca interna, and theca externa cells were observed clearer in ovary which was vitrified with 30 % EG than those with 30% DMSO and combination of 15% EG + 15% DMSO. As conclusion, 30% EG was able to protect ovary morphological integrity better than 15 % EG + 15% DMSO and 30% DMSO. Furthermore, combination of 15% EG+ 15 % DMSO was relatively better in protecting ovary follicle morphological integrity compared to 30% DMSO.

scholarly journals Relaxin protein and gene expression in ovarian follicles of immature pigs

1998 ◽  
Vol 21 (2) ◽  
pp. 179-187 ◽  
Author(s):  
KM Ohleth ◽  
Q Zhang ◽  
CA Bagnell
Keyword(s):  
Gene Expression ◽  
Granulosa Cells ◽  
Follicular Fluid ◽  
Ovarian Follicle ◽  
Follicular Development ◽  
Ovarian Follicles ◽  
In Vitro Growth ◽  
Follicle Size ◽  
Theca Interna

Relaxin production by the ovarian follicle of gonadotropin-primed, prepubertal gilts is well documented. As far as we are aware, a source of relaxin in pig follicles, independent of gonadotropins, has not yet been reported. Therefore, the objective of this study was to determine whether relaxin is produced in porcine follicles in the absence of exogenous or cyclic gonadotropins. In immature pigs, immunoreactive relaxin was detected in fluids from small (1-3 mm), medium (4-5 mm) and large (>6 mm) follicles and localized to the theca interna of large follicles. Relaxin levels in follicular fluid significantly increased with follicle size (P<0.05). Relaxin mRNA was detected in whole small- and medium-sized follicles. In large follicles, the relaxin gene was expressed in thecal layers, but not granulosa cells. The abundance of relaxin transcript did not change with follicle size. In summary, relaxin protein and mRNA were detected in porcine follicles from immature animals, indicating that relaxin is produced in the porcine follicle in the absence of exogenous or cyclic gonadotropins. Relaxin's in vitro growth effects on porcine granulosa and theca cells support this follicular relaxin as a growth modulator during porcine follicular development.

scholarly journals Human Granulosa Cells—Stemness Properties, Molecular Cross-Talk and Follicular Angiogenesis

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1396
Author(s):  
Claudia Dompe ◽  
Magdalena Kulus ◽  
Katarzyna Stefańska ◽  
Wiesława Kranc ◽  
Błażej Chermuła ◽  
...  
Keyword(s):  
Stem Cells ◽  
Granulosa Cells ◽  
Polycystic Ovary ◽  
Ovarian Follicle ◽  
Cumulus Cells ◽  
Ovary Syndrome ◽  
Different Types ◽  
Metabolite Exchange ◽  
Reproductive Techniques ◽  
New Strategies

The ovarian follicle is the basic functional unit of the ovary, comprising theca cells and granulosa cells (GCs). Two different types of GCs, mural GCs and cumulus cells (CCs), serve different functions during folliculogenesis. Mural GCs produce oestrogen during the follicular phase and progesterone after ovulation, while CCs surround the oocyte tightly and form the cumulus oophurus and corona radiata inner cell layer. CCs are also engaged in bi-directional metabolite exchange with the oocyte, as they form gap-junctions, which are crucial for both the oocyte’s proper maturation and GC proliferation. However, the function of both GCs and CCs is dependent on proper follicular angiogenesis. Aside from participating in complex molecular interplay with the oocyte, the ovarian follicular cells exhibit stem-like properties, characteristic of mesenchymal stem cells (MSCs). Both GCs and CCs remain under the influence of various miRNAs, and some of them may contribute to polycystic ovary syndrome (PCOS) or premature ovarian insufficiency (POI) occurrence. Considering increasing female fertility problems worldwide, it is of interest to develop new strategies enhancing assisted reproductive techniques. Therefore, it is important to carefully consider GCs as ovarian stem cells in terms of the cellular features and molecular pathways involved in their development and interactions as well as outline their possible application in translational medicine.

scholarly journals rdgE: A Novel Retinal Degeneration Mutation in Drosophila melanogaster

Genetics ◽  
1996 ◽  
Vol 144 (1) ◽  
pp. 127-138
Author(s):  
Troy Zars ◽  
David R Hyde
Keyword(s):  
Electron Microscopy ◽  
Retinal Degeneration ◽  
Light Response ◽  
Neuronal Membrane ◽  
Constant Darkness ◽  
Multivesicular Bodies ◽  
Photoreceptor Degeneration ◽  
Transmission Electron ◽  
Phototransduction Cascade ◽  
Membrane Biosynthesis

Abstract We report isolating the Drosophila retinal degeneration E (rdgE) mutation. The hypomorphic rdgE  1 allele causes rapid photoreceptor degeneration in light and a slower rate of degeneration when the flies are raised in constant darkness. The rdgE  1 flies exhibited an electrophysiological light response that decreased with age, coinciding with the degeneration. This suggests that degeneration caused the loss of the light response. We determined that the ninaE (rhodopsin) mutation, but not norpA [phospholipase C (PLC)], slowed the rdgE-dependent degeneration. This was consistent with the light-enhanced degeneration, but revealed that the degeneration is independent of the PLC-mediated phototransduction cascade. Transmission electron microscopy revealed that rdgE  1 photoreceptors exhibited a number of vesicular transport defects including unpacking/vesiculation of rhabdomeres, endocytosis of novel vesicles by photoreceptors, a buildup of very large multivesicular bodies, and an increased amount of rough endoplasmic reticulum. We determined that the rdgE null phenotype is a late embryonic lethality. Therefore, rdgE  + is required in cells outside of the retina, quite possibly in a large number of neurons. Thus, rdgE may define a mutational class that exhibits both light-enhanced retinal degeneration and a recessive null lethality by perturbing neuronal membrane biosynthesis and/or recycling.

scholarly journals Small RNA sequencing reveals distinct nuclear microRNAs in pig granulosa cells during ovarian follicle growth

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Derek Toms ◽  
Bo Pan ◽  
Yinshan Bai ◽  
Julang Li
Keyword(s):  
Granulosa Cells ◽  
Small Rna ◽  
High Throughput Sequencing ◽  
Ovarian Function ◽  
Ovarian Follicle ◽  
Small Rna Sequencing ◽  
Cell Fractionation ◽  
Steroid Synthesis ◽  
Non Coding Rna ◽  
Dna Binding Sites

AbstractNuclear small RNAs have emerged as an important subset of non-coding RNA species that are capable of regulating gene expression. A type of small RNA, microRNA (miRNA) have been shown to regulate development of the ovarian follicle via canonical targeting and translational repression. Little has been done to study these molecules at a subcellular level. Using cell fractionation and high throughput sequencing, we surveyed cytoplasmic and nuclear small RNA found in the granulosa cells of the pig ovarian antral preovulatory follicle. Bioinformatics analysis revealed a diverse network of small RNA that differ in their subcellular distribution and implied function. We identified predicted genomic DNA binding sites for nucleus-enriched miRNAs that may potentially be involved in transcriptional regulation. The small nucleolar RNA (snoRNA) SNORA73, known to be involved in steroid synthesis, was also found to be highly enriched in the cytoplasm, suggesting a role for snoRNA species in ovarian function. Taken together, these data provide an important resource to study the small RNAome in ovarian follicles and how they may impact fertility.

scholarly journals Functional Entry of Baculovirus into Insect and Mammalian Cells Is Dependent on Clathrin-Mediated Endocytosis

2006 ◽  
Vol 80 (17) ◽  
pp. 8830-8833 ◽  
Author(s):  
Gang Long ◽  
Xiaoyu Pan ◽  
Richard Kormelink ◽  
Just M. Vlak
Keyword(s):  
Electron Microscopy ◽  
Mammalian Cells ◽  
Low Ph ◽  
Coated Pits ◽  
Immuno Electron Microscopy ◽  
Endocytosis Pathway ◽  
Ph Dependent ◽  
Budded Virus

ABSTRACT Entry of the budded virus form of baculoviruses into insect and mammalian cells is generally thought to occur through a low-pH-dependent endocytosis pathway, possibly through clathrin-coated pits. This insight is primarily based on (immuno)electron microscopy studies but requires biochemical support to exclude the use of other pathways. Here, we demonstrate using various inhibitors that functional entry of baculoviruses into insect and mammalian cells is primarily dependent on clathrin-mediated endocytosis. Our results further suggest that caveolae are somehow involved in baculovirus entry in mammalian cells. A caveolar endocytosis inhibitor, genistein, enhances baculovirus transduction in these cells considerably.

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