The relationship between oöcyte and follicle in the hen's ovary as shown by electron microscopy

Development ◽  
1965 ◽  
Vol 13 (2) ◽  
pp. 215-233
Author(s):  
Ruth Bellairs
Keyword(s):  
Electron Microscopy ◽  
Cell Membrane ◽  
Raw Materials ◽  
Follicle Cell ◽  
Follicle Cells ◽  
Vitelline Membrane ◽  
Zona Radiata ◽  
Golgi Bodies ◽  
Pass Through ◽  
The Relationship

In the adult hen each oöcyte is surrounded by a capsule of follicle cells and all the raw materials that enter the oöcyte must pass through this capsule. It is not surprising, therefore, that the morphological relationships between the follicle and the oöcyte are of a highly specialized nature. Several workers have studied them, mainly by light microscopy, but their findings have not been unanimous, largely because of difficulties in resolving fine details. For instance, although it has frequently been suggested that certain structures pass from the follicle cell into the oöcyte, these structures have been interpreted by different authors as Golgi bodies, as mitochondria or as fat drops. Similarly, there have been several different theories about the relationship between the cell membrane of the oöcyte, the zona radiata and the vitelline membrane.

The oocyte of the domestic chicken shortly after hatching, studied by electron microscopy

Development ◽  
1966 ◽  
Vol 15 (3) ◽  
pp. 297-316
Author(s):  
M. L. Greenfield
Keyword(s):  
Electron Microscopy ◽  
Cell Membrane ◽  
Follicle Cell ◽  
Domestic Chicken ◽  
Follicle Cells ◽  
Golgi Bodies ◽  
New Type

The cytoplasm of oocytes is highly complex. This has been demonstrated by light-microscopists not only in birds but in most other classes of animals (see review by Raven, 1961), although the various authors have not always agreed as to the nature of the cytoplasmic components nor as to their significance. For instance, in birds it has often been reported that certain structures pass from the follicle cells into the oocyte, but these have been identified as Golgi bodies, as mitochondria or as lipid drops by different authors. Recently, however, it has been demonstrated by electron microscopy that in the oocytes of adult birds the structures are instead a new type of organelle formed by a modification of the follicle-cell membrane and they have been termed ‘lining bodies’ (Bellairs, 1964, 1965). The role of these structures is not understood and it is clear that more information is needed about them.

Aspects of the development of yolk spheres in the hen's oöcyte, studied by electron microscopy

Development ◽  
1967 ◽  
Vol 17 (2) ◽  
pp. 267-281
Author(s):  
Ruth Bellairs
Keyword(s):  
Electron Microscopy ◽  
Cell Nucleus ◽  
Raw Materials ◽  
Morphological Changes ◽  
Laying Hen ◽  
Follicle Cells ◽  
Balbiani Body ◽  
Hen’S Egg ◽  
Pass Through ◽  
Yolk Nucleus

The yolk of the hen's egg is composed mainly of proteins, lipids and water (see reviews by Bellairs, 1964; Williams, 1966). It consists essentially of yolk spheres floating in an aqueous protein medium (Grodziński, 1939; Bellairs, 1961). The raw materials from which the yolk is formed are synthesized in the liver of the laying hen and pass from there in the blood to the ovary (see reviews by Romanoff, 1960; Bellairs, 1964). Each oöcyte is enclosed in a capsule of follicle cells, and all the raw materials pass through this capsule before they enter the oöcyte. The morphological changes that take place within the oöcyte as the yolk spheres form have been described previously by light microscopists who have produced a variety of theories to explain their observations. Formerly, it was supposed that yolk arose in the so-called ‘yolk nucleus’, or Balbiani body, which lies alongside the cell nucleus, but few would subscribe to this theory now.

An electron microscopic study of vitellogenesis and egg membrane formation in Lytta nuttalli Say (ColeopterarMeloidae)

1970 ◽  
Vol 48 (4) ◽  
pp. 651-657 ◽  
Author(s):  
P. R. Sweeny ◽  
N. S. Church ◽  
J. G. Rempel ◽  
Wendy Frith
Keyword(s):  
Electron Microscopy ◽  
Plasma Membrane ◽  
Follicle Cells ◽  
Vitelline Membrane ◽  
Electron Microscopic ◽  
Yolk Formation ◽  
Membrane Formation ◽  
Electron Dense Material ◽  
Egg Membrane ◽  
Pass Through

Vitellogenesis and egg membrane formation in the terminal ovarian follicles of Lytta nuttatii were investigated by electron microscopy. Three kinds of yolk globules are produced. They apparently are composed predominantly of carbohydrates, lipids, and proteins, respectively. The "carbohydrate" and "lipid" yolk are assembled in the ooplasm, the former by rough endoplasmic reticulum and the latter by Golgi complexes. Their production begins early in oogenesis. "Proteid" yolk formation begins somewhat later. The "proteid" yolk globules evidently are formed from exfraovarian materials that pass through large spaces that develop between the follicular epithelial cells, then through the oocyte plasma membrane by pinocytosis. Fairly late in development, glycogen granules appear in the inner ooplasm. In the nearly fully grown follicle, the "membranous system" of the vitelline membrane is elaborated. It probably is formed largely from an electron-dense material of undetermined origin that accumulates outside the bases of the oocyte plasma membrane microvilli. Immediately after completion of the vitelline membrane, the chorion is laid down, presumably from dense globules of material produced by Golgi complexes in the follicle cells.

Studies on the Ovarian Follicle Cells of Drosophila

1963 ◽  
Vol s3-104 (67) ◽  
pp. 297-320
Author(s):  
R. C. KING ◽  
ELIZABETH A. KOCH
Keyword(s):  
Ovarian Follicle ◽  
Protein A ◽  
Follicle Cell ◽  
Follicle Cells ◽  
Vitelline Membrane ◽  
Membrane Material ◽  
Adjacent Layer ◽  
Membrane Formation ◽  
Precursor Material ◽  
Egg Shell

Studies are described of the ultrastructure of the follicle cells which invest the oocyte of Drosophila melanogaster at the time of vitelline membrane formation. Of particular interest are organelles made up of endoplasmic reticulum organized into a husk of concentric lamellae which surround lipidal droplets. These epithelial bodies are seen only at the time the vitelline membrane is being formed, and it is assumed therefore that the lipidal material of the epithelial body may be utilized somehow in the fabrication of the vitelline membrane. Cytochemical studies have shown this membrane to contain at least 5 classes of compounds; a protein, two lipids (which may be distinguished by differences in their resistance to extraction by various solvents), and 2 polysaccharides (1 neutral and 1 acidic). Studies were made of vitelline membrane formation in the ovaries of flies homozygous for either of 2 recessive, female-sterile genes (tiny and female sterile). In the case of the ty mutation vitelline membrane material is sometimes secreted between follicle and nurse cells, while in the mutant fes vitelline membrane is observed in rare instances to be secreted between follicle cells and an adjacent layer of tumour cells. In the latter case the vitelline membrane shows altered cytochemical properties. The fact that vitelline membrane can be secreted by follicle cells not adjacent to an oocyte demonstrates that it is the follicle cell rather than the oocyte that plays the major role in the secretion of the precursor material of the vitelline membrane. Subsequently the follicle cells secrete the egg-shell, or chorion, which is subdivided into a dense, compartmented, inner endochorion, and a pale, outer exochorion. A description is given of the ultrastructure of the follicle cells during the secretion of the endochorion and the exochorion. The endochorion contains a protein, a polysaccharide, and a lipid, all of which may be distinguished cytochemically from the vitelline membrane compounds. The exochorion contains large amounts of acidic mucopolysaccharides. Specialized follicle cells form the micropylar apparatus and the chorionic appendages. The formation of the chorion and chorionic appendages is discussed in the light of information gained from abnormalities of the chorions and chorionic appendages seen in ty and fs 2.1 oocytes. Subsequent to the time the egg leaves the ovariole a layer of waterproofing wax is secreted between the vitelline membrane and the chorion.

Memoirs: A Study of the Cytoplasmic Inclusions and Nucleolar Phenomena during the Oogenesis of the Mouse

1933 ◽  
Vol s2-75 (300) ◽  
pp. 697-721
Author(s):  
R.A. R. GRESSON
Keyword(s):  
Golgi Apparatus ◽  
Close Association ◽  
Large Body ◽  
Follicle Cell ◽  
Nuclear Body ◽  
Follicle Cells ◽  
Present Contribution ◽  
Cytoplasmic Inclusions ◽  
Golgi Bodies ◽  
Nucleolar Material

1. The Golgi apparatus of the germinal epithelium consists of a dark mass of material situated at one pole of the nucleus. The mitochondria occur scattered throughout the cytoplasm. 2. The Golgi material of the very early oocyte consists of rods and granules clumped together to form a large body at one pole of the nucleus; smaller masses of Golgi material may also be present. 3. In the young oocyte, surrounded by a follicle wall, a single juxta-nuclear body is present; at a later stage the individual Golgi elements break away from the juxta-nuclear body and become distributed throughout the ooplasm. 4. In the late oocytes the Golgi elements occur in close association with the mitochondrial clumps and also scattered through the ooplasm. In tubal eggs the Golgi bodies are smaller in size and more numerous than in the ovarian ova. 5. It is concluded that the large mitochondria of Lams and Doorme correspond to the oocyte Golgi elements of the present contribution. The behaviour of the Golgi material during the growth of the ovum resembles that of the eggs of other mammals. The present findings on the structure of the juxta-nuclear Golgi material agrees with Nihoul's account for the rabbit. 6. The mitochondria of the young oocytes occur scattered through the ooplasm, but are more numerous in the vicinity of the nucleus and Golgi material. Later, the majority of the mitochondria become collected into clumps; in the tubal eggs the mitochondrial clumps are more numerous. 7. The Golgi apparatus of young follicles is situated between the follicle-cell nucleus and the pole of the cell directed towards the oocyte; in follicles consisting of several layers the position of the Golgi apparatus varies, while in fully-formed follicles the Golgi material of many of the cells surrounding the follicular cavity are directed towards the cavity. This agrees with Henneguy's findings for the Golgi apparatus of the follicle-cells of the guinea-pig. The mitochondria of the follicle-cells occur scattered through the cytoplasm but are more numerous towards the pole of the cell adjoining the oocyte. 8. The number of nucleoli present in the early oocyte varies from one to five; the majority of the older oocytes contain a single nucleolus but two may be present. Extrusion into the ooplasm of nucleolar material takes place; the nucleoli and the nucleolar extrusions are basophil (Mann's methyl-blue eosin). 9. Fatty yolk is not present in the mouse ovum. It is suggested that the Golgi elements and mitochondria play some part in yolk-formation, and that some of the granules formed by the fragmentation of the nucleolar extrusions are added to the yolkglobules already present. The yolk-globules of unsegmented tubal eggs are situated towards one pole of the cell; at the twocell stage they appear to be evenly distributed between the two cells. 10. In degenerating eggs the mitochondria are clumped; the Golgi bodies occur in small groups or are closely applied to the mitochondrial clumps. In eggs which have undergone fragmentation the Golgi bodies occur in groups, while the majority of the mitochondria are clumped. The fat-globules, previously recorded by Kingery in degenerating eggs, were identified. In material treated by Ciaccio's method for the identification of fats, appearances suggest that the Golgi elements, and possibly the mitochondria, give rise to fat. Yolk-globules could not be distinguished in the late stages of these eggs.

The eggshell of Drosophila melanogaster. II. New staging characteristics and fine structural analysis of choriogenesis

1986 ◽  
Vol 64 (10) ◽  
pp. 2152-2175 ◽  
Author(s):  
Lukas H. Margaritis
Keyword(s):  
Electron Microscopy ◽  
Light And Electron Microscopy ◽  
Dark Field ◽  
Posterior Pole ◽  
Follicle Cells ◽  
Vitelline Membrane ◽  
Simultaneous Formation ◽  
Last Stage ◽  
Flocculent Material ◽  
Factor C

The characteristics of the stages of choriogenesis have been identified using light and electron microscopy. Nine stages have been discerned (11A, 11B, 12A, 12B, 12C, 13A, 13B, 14A, 14B), replacing the four stages used so far (11, 12, 13, 14). Characteristics used to determine the stage of the choriogenesis include (a) the size of oocyte as compared with the whole follicle, (b) the length of the chorionic appendages, and (c) the fine structure of the chorionic layers at the main shell and at the specialized regions. Factors a and b were detected by dark-field light microscopy on living follicles, whereas factor c was studied with electron microscopy. At stage 11A the vitelline membrane has just been completed. At stage 11B the follicle cells secrete the wax layer and the respiratory appendages start to form. Stage 12A follicles secrete endochorion at the anterior pole and the appendages elongate, whereas at stage 12B the main shell follicle cells start to secrete endochorion complex. Stage 12C shows initiation of pillar formation at the main shell and 150 μm long appendages. Stage 13A is characterized by 200 μm long appendages and formation of endochorionic cavities at the main shell, through the participation of a "flocculent" material. At stage 13B the endochorionic "roof is formed, which is completed at stage 14A by the simultaneous formation of the "roof network." The last stage, 14B, exhibits 300 μm long appendages and the secretion of exochorion over the entire follicle. The above stages are accompanied by region-specific formation of specialized structures which include the respiratory appendages, the operculum, the posterior pole, the micropyle, and the collar.

scholarly journals Gap junctions between the oocyte and companion follicle cells in the mammalian ovary.

1976 ◽  
Vol 71 (2) ◽  
pp. 680-686 ◽  
Author(s):  
E Anderson ◽  
D F Albertini
Keyword(s):  
Electron Microscopy ◽  
Gap Junctions ◽  
Functional Significance ◽  
Adult Mouse ◽  
Freeze Fracture ◽  
Follicle Cell ◽  
Neonatal Rat ◽  
Follicle Cells ◽  
Freeze Fracture Electron Microscopy ◽  
Fracture Electron

Tracer and freeze-fracture electron microscopy of the ovaries of neonatal rat and adult mouse, rat, rabbit, and primate have revealed the presence of gap junctions between follicle cells and oocytes. The junctional connections are found at the ends of follicle cell projections which traverse the zona pellucida and terminate upon microvilli and evenly contoured nonmicrovillar regions of the oolemma. Gap junctions are often seen associated with a macula adherens type of junction. The gap junctions occasionally consist of minute ovoid plaques, but nore frequently appear as rectilinear single- or multiple-row aggregates of particles on the P-face or pits on the E-face. The functional significance of follicle cell-oocyte gap junctions is discussed with respect to the regulation of meiosis and luteinization.

THE STRUCTURE AND DEVELOPMENT OF THE EXTERNAL MEMBRANE IN YOUNG EGGS OF THE BROOK TROUT, SALVELINUS FONTINALIS (MITCHILL)

1966 ◽  
Vol 44 (2) ◽  
pp. 173-190 ◽  
Author(s):  
Donal A. Hurley ◽  
Kenneth C. Fisher
Keyword(s):  
Electron Microscopy ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Morphological Changes ◽  
The Other ◽  
Follicular Cells ◽  
Immature Oocytes ◽  
Zona Radiata ◽  
Pore Canals ◽  
The Relationship

A study of the external membranes of the developing oocyte of the brook trout, Salvelinus fontinalis, was made by means of electron microscopy. The membrane, zona radiata, which becomes "hardened" in mature eggs after they are shed into water, was observed to begin development at the bases of microvilli which project from the surface of the oocyte. This membrane grows until in the mature egg it is about 50 μ thick. The zona radiata is completely permeated by numerous pore canals. In immature oocytes, the pore canals contain microvilli which arise from the surface of the oocyte. The microvilli make contact with the follicular cells surrounding the developing oocyte. Morphological changes which occur in the zona radiata and the other layers of developing oocytes are described at several stages of development. The relationship between morphological changes in the membranes and the transport of nutrients to the developing oocyte is discussed.The nomenclature of the membranes of the mature trout egg is discussed in relation to the findings of the present study. It is concluded that primary membranes and perhaps secondary membranes are present in the mature trout egg.

Further Information Concerning the Envelopes Surrounding Dipteran Eggs

1964 ◽  
Vol s3-105 (70) ◽  
pp. 209-212
Author(s):  
R. C. KING
Keyword(s):  
Drosophila Melanogaster ◽  
Thin Layer ◽  
Follicle Cell ◽  
Follicle Cells ◽  
Vitelline Membrane ◽  
Anopheles Maculipennis ◽  
Drosophila Embryos

A centripetal migration of follicle cells, which results in a separation of egg and nurse chambers, occurs in higher dipterans like Drosophila melanogaster but not in lower dipterans like Anopheles maculipennis. In Anopheles and Drosophila, while the vitelline membrane can be secreted in the absence of the oocyte, the follicle cells must be present. This suggests that the follicle cell is the governing agent in the synthesis of the vitelline membrane. The envelopes of Drosophila embryos differ from those surrounding ovarian eggs in that a membrane about 0.04 µ thick lies directly outside the vitelline membrane. This thin layer is thought to represent a waterproofing wax which forms once the egg leaves the ovariole.

The eggshell of Drosophila melanogaster. V. Structure and morphogenesis of the micropylar apparatus

1986 ◽  
Vol 64 (11) ◽  
pp. 2509-2519 ◽  
Author(s):  
Flora E. Zarani ◽  
Lukas H. Margaritis
Keyword(s):  
Drosophila Melanogaster ◽  
Outer Part ◽  
Follicle Cell ◽  
Follicle Cells ◽  
Vitelline Membrane ◽  
Mature Stage ◽  
Border Cells ◽  
Border Cell ◽  
Paracrystalline Structure ◽  
Cell Subpopulations

The micropylar apparatus in Drosophila melanogaster consists of two parts. The inner part is a protrusion of vitelline membrane, whereas the outer part is a chorionic protrusion containing a canal, through which the spermatozoon enters. In the formation of the micropylar apparatus two follicle cell subpopulations are involved: the border cells, i.e., a group of 9 follicle cells, and the peripheral cells (about 36 cells). The morphogenesis of the micropyle starts at stage 10B, when the border cells secrete the paracrystalline region of the vitelline membrane. The micropylar canal (length 7 μm, diameter 0.7 μm) and the pocket that penetrates within the paracrystalline structure are moulded by two border cell projections, full of microtubules. The formation of the micropyle terminates at stage 14B, when its chorionic part is completed and the border cell projections degenerate. The structure of the micropyle in fertilized and unfertilized laid eggs differs from the mature (stage 14B) egg in that the vitelline membrane is modified and appears homogeneous as in the rest of the eggshell. These transformations seem to be unrelated to sperm entry.

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