A light- and electron-microscope study of the oocyte nucleus during development of the antral follicle in the prepubertal mouse

1975 ◽  
Vol 17 (3) ◽  
pp. 589-615
Author(s):  
L.A. Chouinard
Keyword(s):  
Meiotic Prophase ◽  
Functional Organization ◽  
Current Knowledge ◽  
Light And Electron Microscopy ◽  
Antral Follicle ◽  
Mouse Oocyte ◽  
Oocyte Nucleus ◽  
Follicle Development ◽  
Preovulatory Follicle ◽  
Functional Changes

The ordered changes which occur in the structural organization of the mouse oocyte nucelus during the preparatory, the maturative and the preovulatory stages of antral follicle development, have been studied under both light and electron microscopy. All observations have been made on those antral follicles whose development is initiated on postnatal day 14 and completed by postnatal day 28 in prepubertal animals of the ICR albino mouse strain. The formed entities that can be recognized within the oocyte nucleus during that period are the condensing bivalents, the heterochromatic knobs, the nucleolus and the extranucleolar bodies. At the onset of antral follicle development, the highly unravelled dictyate bivalents are seen to take on a lampbrush-type configuration. Subsequent condensation of these lampbursh bivalents appears to be a very gradual and lengthy process that extends over almost the entire period of antral follicle development. The shortening and thickening of the lampbrush bivalents are best interpreted as resulting from the withdrawal of their lateral loop-like projections into the chromosome axes and from the focal aggregation of these axes into compact chromatin masses. Electron-opaque granules, which appear within the oocyte nucleus during the preparatory and maturative follicle stages, are seen to be intimately associated with these condensing bivalents. A number of Feulgen-positive heterochromatic knobs make their appearance in contact with certain bivalents during the preparatory follicle stage. These knobs are not reincorporated as such into the condensing chromatin masses and undergo disintegration and dissolution during the preovulatory follicle stage. The size, shape and ultrastructural features of the nucleolus remain unchanged thoughout the period of antral follicle development. Breakdown and dissolution of the nucleolar mass is a swift process that takes place only in the fully mature preovulatory follicle and more or less concomitantly with the dismantling of the nuclear envelope. The extranucleolar bodies increase noticeably in size during the preparatory and the maturative follicle stages; they shrink in size and undergo dissolution during the preovulatory stage of antral follicle development. An attempt is made to interpret these morphological changes in the light of current knowledge concerning the architectural and functional organization of the oocyte nucleus in general during meiotic prophase. The relevant observational evidence would be consistent with the view that, during antral follicle deveopment, the mouse oocyte nucleus is not, as too often assumed, in a period of arrested evolution; its formed components undergo structural, maturational and functional changes which are of significance not only for the resumption of the first meiotic prophase but also for the early development of the embryo.

Mouse oocyte differentiation during antral follicle development

2006 ◽  
Vol 69 (6) ◽  
pp. 408-414 ◽  
Author(s):  
Sandra Cecconi ◽  
Gianna Rossi ◽  
Maria Grazia Palmerini
Keyword(s):  
Antral Follicle ◽  
Mouse Oocyte ◽  
Follicle Development ◽  
Oocyte Differentiation

A Light- And Electron-Microscope Study of the Nucleolus During Growth of the Oocyte in the Prepubertal Mouse

1971 ◽  
Vol 9 (3) ◽  
pp. 637-663
Author(s):  
L. A. CHOUINARD
Keyword(s):  
Structural Organization ◽  
Functional Organization ◽  
Current Knowledge ◽  
Light And Electron Microscopy ◽  
Fold Increase ◽  
Dense Fibrillar Component ◽  
Parallel Increase ◽  
Nucleolar Material ◽  
Nucleolar Volume ◽  
Fibrillar Component

The ordered changes which occur in the structural organization of the nucleolus during growth of the mouse oocyte have been studied by both light and electron microscopy. All observations have been made on those oocytes whose growth is initiated on the day of birth and completed by postnatal day 14 in prepubertal animals of the ICR albino mouse strain. During that period the oocyte nucleolus undergoes an approximate 90-fold increase in volume. During the unilaminar follicle stage (from birth to postnatal day 4), the growing nucleolus exhibits an overall reticulated-type of structure consisting of: (1) a moderately electron-dense fibrillogranular component occupying most parts of the nucleolar framework; (2) an electron-transparent nucleoplasm-like component filling the numerous interstices of the nucleolar framework; (3) an electron-dense fibrillar component located in the peripheral portion of a number of small islands widely and uniformly scattered within the nucleolar framework, and (4) a slightly less-dense fibrillar component situated in the central portion of these same islands and referred to as fibrillar centres. Increase in nucleolar volume during that stage is brought about mainly through an increase in the overall dimensions of the fibrillogranular framework, accompanied by a parallel increase in the number and, to a certain extent, the size of its electron-transparent interstices. During the bilaminar follicle stage (postnatal day 5 through 8), the following structural and organizational changes take place more or less concomitantly within the still enlarging nucleolar mass: (1) the fibrillogranular framework becomes predominantly fibrillar in texture as a result of what appears to be an unravelling or unfolding of its constituent granules of ribosomal dimensions; (2) the nucleolar interstices decrease rapidly both in number and size because of the accumulation within their interior of a material the texture and density of which match that present in the nucleolar framework itself; and (3) a number of rounded electron-transparent spaces, the nucleolar vacuoles, make their appearance in the regions formerly occupied by some of the fibrillar islands and adjacent interstices. Increase in nucleolar volume during that stage is largely due to the appearance and subsequent enlargement of the nucleolar vacuoles in question. During the plurilaminar follicle stage (postnatal day 9 through 14), the following sequential events take place within the nucleolar mass: (1) a moderately electron-dense fibrillogranular material accumulates within the nucleolar vacuoles; (2) this fibrillogranular material, which eventually fills all vacuolar spaces, undergoes degranulation and a concomitant increase in density, eventually matching that of the rest of the nucleolar mass; (3) all remnants of the lightly stained nucleolar interstices disappear from view; and (4) the fully grown rounded nucleolus finally appears as a dense, compact mass, exclusively fibrillar in texture, and exhibiting no internal structural organization. An attempt is made to interpret these changes in the light of current knowledge concerning thearchitectural and functional organization of the mammalian nucleolus in general. The observations are consistent with the view that the nucleolus, during growth of the primary oocyte, is the site of massive synthesis and storage of nucleolar material.

An Electron-Microscope Study of the Extranucleolar Bodies during Growth of the Oocyte in the Prepubertal Mouse

1973 ◽  
Vol 12 (1) ◽  
pp. 55-69
Author(s):  
L. A. CHOUINARD
Keyword(s):  
Functional Organization ◽  
Current Knowledge ◽  
Oocyte Nucleus ◽  
Oocyte Growth ◽  
Fibrillar Material ◽  
The Third ◽  
Morphological Findings ◽  
Coiled Bodies ◽  
Differential Gene ◽  
Morphological Expression

The dictyate nucleus of the growing mouse oocyte exhibits, besides the nucleolus, 3 ultrastructurally distinct types of smaller formed entities referred to as extranucleolar bodies. The extranucleolar bodies of the first type (fibrillogranular bodies) consist of intermingled masses made up of closely arranged convoluted fibrils, 6-10 nm in width, interspersed with electrondense granules approximately 15 nm in diameter. The extranucleolar bodies of the second type (fibrillar bodies) are composed of an entanglement of loosely arranged convoluted fibrils 4-10 nm in diameter; such bodies are also characterized by the presence within their mass of irregularly shaped widely scattered islands of varying sizes made up of densely packed fibrillar material exhibiting a somewhat greater electron opacity. The extranucleolar bodies of the third type (coiled bodies) appear to consist of an aggregate of highly contorted threads, the thickness of which varies from 20 to 35 nm; the threads themselves are composed of bundles of fibrils 5 nm thick which are irregularly twisted along their axis. An attempt is made to interpret these morphological findings in the light of current knowledge concerning the architectural and functional organization of the oocyte nucleus in general during the protracted dictyate stage of meiotic prophase. Our observations would be consistent with the view that the various types of extranucleolar bodies are morphological expression - like the puffs of the polytene and the loops or spheroids of the lampbrush chromosomes - of differential gene activity on the part of the localized regions of the chromosomes during oocyte growth.

265. Increased FSH activity increases primordial follicle reserve and enhances preovulatory follicle survival in transgenic FSH female mice

2008 ◽  
Vol 20 (9) ◽  
pp. 65
Author(s):  
K. J. McTavish ◽  
K. A. Walters ◽  
D. J. Handelsman ◽  
C. M. Allan
Keyword(s):  
Ovarian Follicle ◽  
Primordial Follicle ◽  
Antral Follicle ◽  
Follicle Development ◽  
Preovulatory Follicle ◽  
Primary Follicle ◽  
Primordial Follicles ◽  
Female Mice ◽  
Depletion Rate ◽  
Reproductive Ageing

The mammalian female reproductive lifespan is determined by the depletion rate of the finite ovarian follicle reserve established before or shortly after birth. Follicle formation, initiation and early growth are thought to be independent of follicle-stimulating hormone (FSH), whereas antral follicle development requires FSH stimulation. Rising serum FSH is one of the earliest signs of reproductive ageing in women, coinciding with declining fecundity and an accelerated decline in remaining follicle reserves, but whether or not increased FSH plays a direct or feed-forward role in accelerating reproductive ageing remains undetermined. We previously described transgenic (Tg) mice with rising serum human FSH that produced larger litter sizes <20 weeks of age, then rapidly declining litter size from 20–40 weeks old (wo) culminating in premature infertility1. Despite declining fertility, ageing TgFSH females maintained ovulation rates ~3-fold higher than wt females. Follicle quantitation revealed that ovarian antral follicle numbers at diestrus were equivalent in 26 wo TgFSH and wt females. The elevated ovulation rates in TgFSH females may reflect increased preovulatory follicle survival during proestrus, as ~70% of large antral follicles go on to ovulate in TgFSH females, compared with only 30% in wt females. In contrast to the view that higher FSH may increase follicle development and consequently accelerate follicle depletion, examination of follicle reserve revealed that subfertile or infertile 26–52 wo TgFSH females exhibited increased total ovarian primordial follicle numbers (60%, P < 0.05) with no significant change in primary follicle numbers compared with age-matched wt females. Therefore, increased FSH activity appeared to act as a survival factor for primordial follicles. Our current analysis of increased FSH actions in female mice suggests that FSH may enhance the survival of both early (primordial) and late (preovulatory) follicle populations. (1) McTavish KJ et al. Endocrinology. 2007 Sep;148(9):4432–9.

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 Preovulatory follicle development and ovulation in the brushtail possum (Trichosurus vulpecula) monitored by repeated laparoscopy

Reproduction ◽  
1997 ◽  
Vol 110 (2) ◽  
pp. 361-370 ◽  
Author(s):  
J. L. Crawford ◽  
G. H. Shackell ◽  
E. G. Thompson ◽  
B. J. McLeod ◽  
P. R. Hurst
Keyword(s):  
Brushtail Possum ◽  
Follicle Development ◽  
Trichosurus Vulpecula ◽  
Preovulatory Follicle

scholarly journals Developmental Origins of Kidney Disease: Why Oxidative Stress Matters?

Antioxidants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 33
Author(s):  
Chien-Ning Hsu ◽  
You-Lin Tain
Keyword(s):  
Oxidative Stress ◽  
Kidney Disease ◽  
Current Knowledge ◽  
Future Research ◽  
Antioxidant Systems ◽  
Developmental Origins ◽  
Adult Onset ◽  
Functional Changes ◽  
Health And Disease ◽  
Developing Kidney

The “developmental origins of health and disease” theory indicates that many adult-onset diseases can originate in the earliest stages of life. The developing kidney has emerged as being particularly vulnerable to adverse in utero conditions leading to morphological and functional changes, namely renal programming. Emerging evidence indicates oxidative stress, an imbalance between reactive oxygen/nitrogen species (ROS/RNS) and antioxidant systems, plays a pathogenetic role in the developmental programming of kidney disease. Conversely, perinatal use of antioxidants has been implemented to reverse programming processes and prevent adult-onset diseases. We have termed this reprogramming. The focus of this review is twofold: (1) To summarize the current knowledge on oxidative stress implicated in renal programming and kidney disease of developmental origins; and (2) to provide an overview of reprogramming effects of perinatal antioxidant therapy on renal programming and how this may prevent adult-onset kidney disease. Although early-life oxidative stress is implicated in mediating renal programming and adverse offspring renal outcomes, and animal models provide promising results to allow perinatal antioxidants applied as potential reprogramming interventions, it is still awaiting clinical translation. This presents exciting new challenges and areas for future research.

Mechanisms involved in developmental programming of hypertension and renal diseases. Gender differences

2014 ◽  
Vol 18 (2) ◽  
Author(s):  
Analia Lorena Tomat ◽  
Francisco Javier Salazar
Keyword(s):  
Metabolic Diseases ◽  
Current Knowledge ◽  
Adult Life ◽  
Developmental Programming ◽  
Renal Diseases ◽  
Future Studies ◽  
Functional Changes ◽  
Regulatory Systems ◽  
Increased Risk ◽  
Renal Changes

AbstractA substantial body of epidemiological and experimental evidence suggests that a poor fetal and neonatal environment may “program” susceptibility in the offspring to later development of cardiovascular, renal and metabolic diseases.This review focuses on current knowledge from the available literature regarding the mechanisms linking an adverse developmental environment with an increased risk for cardiovascular, renal and metabolic diseases in adult life. Moreover, this review highlights important sex-dependent differences in the adaptation to developmental insults.Developmental programming of several diseases is secondary to changes in different mechanisms inducing important alterations in the normal development of several organs that lead to significant changes in birth weight. The different diseases occurring as a consequence of an adverse environment during development are secondary to morphological and functional cardiovascular and renal changes, to epigenetic changes and to an activation of several hormonal and regulatory systems, such as angiotensin II, sympathetic activity, nitric oxide, COX2-derived metabolites, oxidative stress and inflammation. The important sex-dependent differences in the developmental programming of diseases seem to be partly secondary to the effects of sex hormones. Recent studies have shown that the progression of these diseases is accelerated during aging in both sexes.The cardiovascular, renal and metabolic diseases during adult life that occur as a consequence of several insults during fetal and postnatal periods are secondary to multiple structural and functional changes. Future studies are needed in order to prevent the origin and reduce the incidence and consequences of developmental programmed diseases.

scholarly journals MODERN CONCEPTION AS TO THE FUNCTIONAL MORPHOLOGY OF THE OLFACTORY SYSTEM AND ITS CHANGES UNDER THE INFLUENCE OF SOME EXOGENOUS POLLUTANTS

2019 ◽  
Vol 23 (3-4) ◽  
pp. 37-40
Author(s):  
A.D. Shkodina ◽  
R.M. Hrinko ◽  
I.I. Starchenko
Keyword(s):  
Environmental Factors ◽  
Olfactory Epithelium ◽  
Functional Organization ◽  
Morphological Changes ◽  
Human Life ◽  
Experimental Studies ◽  
Experimental Models ◽  
Functional Changes ◽  
Olfactory Analyzer ◽  
Long Time

The interaction between a body and an environment provides the main aspects of human life. The study of the functional structure of the olfactory analyzer plays an important role both in clinical and in experimental studies, but the question of its features in humans needs detailed research. The paper presents the modern data of the structural and functional organization of the olfactory analyzer. Particular attention is paid to the structural organization of olfactory bulbs as most complicated and least studied component of the olfactory analyzer. The morphological and functional changes of the olfactory analyzer are developing in some diseases and in action of adverse environmental factors are described while the accentuation is placed on the differences of the mechanism in the pathogenesis of damage to the olfactory analyzer, depending on the nature of the influence of pathogenic factors. In this way as the result of short-term intense effects of the pollutant, irreversible atrophic changes are primarily affected to the olfactory epithelium, thus, to some extent, preventing the spread of the toxin to other analyzer structures. Conversely, a long-term exposure to low doses usually retains the functional activity of the olfactory epithelium, while harmful substances penetrate the central unit of the olfactory analyzer. In such cases, the olfactory dysfunction can be diagnosed after a long time after the start of the cohort with certain pollutants. Currently, studies of the influence of exogenous toxins on various parts of the olfactory analyzer on animal experimental models are quite active. At the same time, the issue of functional and morphological changes in various structural components of the human olfactory analyzer under the influence of negative environmental factors remains poorly understood and requires further morphological and biochemical studies, in order to be able to further develop effective therapeutic and prophylactic means.

scholarly journals Organization of the Macaque Extrastriate Visual Cortex Re-Examined Using the Principle of Spatial Continuity of Function

2011 ◽  
Vol 105 (1) ◽  
pp. 305-320 ◽  
Author(s):  
T. N. Aflalo ◽  
M.S.A. Graziano
Keyword(s):  
Functional Organization ◽  
Current Knowledge ◽  
Dimensional Space ◽  
Macaque Monkey ◽  
Specific Pattern ◽  
Extrastriate Cortex ◽  
Cortical Function ◽  
Spatial Continuity ◽  
Functional Relationships ◽  
Hierarchical Relationships

How is the macaque monkey extrastriate cortex organized? Is vision divisible into separate tasks, such as object recognition and spatial processing, each emphasized in a different anatomical stream? If so, how many streams exist? What are the hierarchical relationships among areas? The present study approached the organization of the extrastriate cortex in a novel manner. A principled relationship exists between cortical function and cortical topography. Similar functions tend to be located near each other, within the constraints of mapping a highly dimensional space of functions onto the two-dimensional space of the cortex. We used this principle to re-examine the functional organization of the extrastriate cortex given current knowledge about its topographic organization. The goal of the study was to obtain a model of the functional relationships among the visual areas, including the number of functional streams into which they are grouped, the pattern of informational overlap among the streams, and the hierarchical relationships among areas. To test each functional description, we mapped it to a model cortex according to the principle of optimal continuity and assessed whether it accurately reconstructed a version of the extrastriate topography. Of the models tested, the one that best reconstructed the topography included four functional streams rather than two, six levels of hierarchy per stream, and a specific pattern of informational overlap among streams and areas. A specific mixture of functions was predicted for each visual area. This description matched findings in the physiological literature, and provided predictions of functional relationships that have yet to be tested physiologically.

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