PERMEABILITY OF THE EGG SHELL OF ACHETA DOMESTICUS (L.), AND THE FATE OF THE VITELLINE MEMBRANE

1960 ◽  
Vol 38 (6) ◽  
pp. 1037-1039 ◽  
Author(s):  
J. E. McFarlane
Keyword(s):  
Embryonic Development ◽  
Water Absorption ◽  
Acheta Domesticus ◽  
Vitelline Membrane ◽  
Egg Shell

The egg shell of Acheta domesticus (L.) is permeable to dyes in the interval between the fragmentation of the endochorion and the secretion of the lipoid layer of the serosal cuticle, i.e. at the beginning of the water absorption period. The vitelline membrane persists throughout the whole of embryonic development, lying between the aforementioned layers from the beginning of water absorption.

WATER ABSORPTION BY THE EGGS OF CRICKETS

1959 ◽  
Vol 37 (4) ◽  
pp. 391-399 ◽  
Author(s):  
J. E. McFarlane ◽  
A. S. K. Ghouri ◽  
C. P. Kennard
Keyword(s):  
Embryonic Development ◽  
Water Absorption ◽  
Acheta Domesticus ◽  
Early Embryonic Development ◽  
Embryonic Stage ◽  
Distilled Water ◽  
Rapid Loss ◽  
Incubation Periods ◽  
Maximal Absorption ◽  
Gryllodes Sigillatus

Absorption of water by the eggs of Acheta configuratus, Gryllodes sigillatus, and a Canadian and a Pakistani strain of Acheta domesticus takes place during early embryonic development. The amount of water absorbed varies from about 60 to 120% of the weight of newly laid eggs, depending on the species or strain. The time of absorption is generally earlier the more rapid is embryonic development, indicating that the embryonic stage during which water is absorbed is similar in all forms. Absorption is more rapid at 33 than at 28 °C. In all forms, a small but rapid loss in water occurs just after maximal absorption; this loss takes place also when the eggs are immersed in distilled water. The incubation periods of the four forms at various temperatures (28–38 °C) are presented.

FURTHER OBSERVATIONS ON WATER ABSORPTION BY THE EGGS OF ACHETA DOMESTICUS (L.)

1960 ◽  
Vol 38 (1) ◽  
pp. 77-85 ◽  
Author(s):  
J. E. McFarlane ◽  
C. P. Kennard
Keyword(s):  
Embryonic Development ◽  
Water Absorption ◽  
Water Loss ◽  
Acheta Domesticus ◽  
Entire Surface ◽  
Maximal Absorption

Eggs of Acheta domesticus (L.) absorb water during the stage of embryonic development in which the serosa surrounds the embryo and yolk. Water is absorbed over the entire surface of the shell. The egg membranes are more permeable to water, as shown by water loss in an unsaturated atmosphere, during the period of water absorption than either before or after; they are also permeable to dyes during the period of water absorption. The mechanism of water absorption is discussed. A possible explanation is presented for water loss after maximal absorption has occurred.

TYROSINASE AND THE STRUCTURE OF THE EGG SHELL OF ACHETA DOMESTICUS (L.)

1961 ◽  
Vol 39 (1) ◽  
pp. 1-9 ◽  
Author(s):  
J. E. McFarlane
Keyword(s):  
Water Absorption ◽  
Normal Development ◽  
Acheta Domesticus ◽  
House Cricket ◽  
Egg Shell

The endochorion of the egg of the house cricket, Acheta domesticus (L.), is composed, in part, of imbricated scales. These scales are revealed in the pattern of melanization of the chorion that results on immersing eggs in aqueous tyrosine before they have begun to absorb water. Such treatment prevents the normal breaking up of the endochorion, but does not prevent water absorption or normal development of the eggs. Failure of the endochorion to fragment in the usual way affects the structure of the underlying lipoid layer of the serosal cuticle.

STRUCTURE AND FUNCTION OF THE EGG SHELL AS RELATED TO WATER ABSORPTION BY THE EGGS OF ACHETA DOMESTICUS (L.)

1960 ◽  
Vol 38 (2) ◽  
pp. 231-241 ◽  
Author(s):  
J. E. McFarlane
Keyword(s):  
Structural Change ◽  
Water Absorption ◽  
Structure And Function ◽  
Acheta Domesticus ◽  
Maximum Thickness ◽  
Egg Shell ◽  
And Function

The shell of the newly laid egg of Acheta domesticus (L.) consists of the chorion, in which two layers can be distinguished: an outer exochorion, about 2.5 μ thick; and an inner endochorion, about 0.4 μ thick, which contains lipoid and a tyrosinase. At about the time water absorption begins, the endochorion breaks up, in a more or less regular way, into many small fragments; as a result, spaces are created in the endochorion, and it seems probable that it is this structural change which permits water to be absorbed by the egg. The breaking up of the endochorion appears to be due to phenolic tanning. Also at about the time water absorption begins, the newly formed serosa begins to lay down the serosal cuticle, first an outer lipoid layer, about 0.4 μ thick, which contains a tyrosinase; and then an inner layer, which is laid down continuously while the serosa exists, and which reaches, at the time water absorption ends, a maximum thickness of 8–10 μ. Thereafter the inner layer of the serosal cuticle is steadily resorbed up to the time the egg is hatched, and the vacated shell consists only of the chorion and the lipoid layer of the serosal cuticle. Water absorption appears to be brought to an end by the phenolic tanning of the lipoid layer of the serosal cuticle.

The Egg Shell of the House Cricket (Acheta Domesticus): An Electron-Microscope Study

1969 ◽  
Vol 5 (1) ◽  
pp. 227-249
Author(s):  
P. J. S. FURNEAUX ◽  
C. R. JAMES ◽  
S. A. POTTER
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Microscope Study ◽  
Electron Microscope Study ◽  
Outer Zone ◽  
Acheta Domesticus ◽  
Vitelline Membrane ◽  
House Cricket ◽  
Stable Part ◽  
Egg Shell

Consecutive changes in two discrete layers of the egg shell of the house cricket, Acheta domesticus, have been claimed to control the uptake of water by the eggs. The development of the shell has been re-investigated with the electron microscope by examination of eggs at different stages of embryogenesis and of ovarioles containing oocytes at various stages of maturity. It is confirmed that fragmentation of the maternal epicuticle and deposition and resorption of the serosal cuticle are the only apparent changes in the shell during development. The existence of a serosal epicuticle is confirmed and a distinction is made between the serosal epicuticle and the vitelline membrane. Previously unreported features of the shell are (i) an outer zone of the maternal endocuticle which seems to be the most stable part of the maternal cuticle, (ii) a microlaminar organization within the scales of the maternal epicuticle, (iii) a vitelline membrane containing specialized regions, which remains distinct from the serosal epicuticle throughout development, and (iv) the osmiophilic character of the serosal epicuticle, its complex fine structure and its origin. Observations on eggs which had just begun to absorb water allow us to suggest that fragmentation involves a shrinkage of the material of which the scales are composed.

Water Uptake and Embryonic Development in Eggs of Chorthippus Brunneus Thunberg (Saltatoria: Acrididae)

1969 ◽  
Vol 50 (2) ◽  
pp. 327-333
Author(s):  
F. MORIARTY
Keyword(s):  
Sodium Chloride ◽  
Embryonic Development ◽  
Water Absorption ◽  
Osmotic Pressure ◽  
Water Uptake ◽  
Water Loss ◽  
Chloride Solutions ◽  
Sodium Chloride Solutions ◽  
Close Relationship ◽  
Further Development

1. The pattern of water absorption by eggs of Chorthippus brunneus varies greatly between individuals. 2. The time at which water is absorbed does not have a close relationship with the stage of embryonic development. 3. Water absorption is not essential for prediapause development. 4. Eggs can only undergo blastokinesis and further development, after diapause is broken, if some water has been absorbed. 5. The rate of water loss or gain varies with the osmotic pressure of sodium chloride solutions. 6. Eggs which have started to absorb water appear to become desiccated more rapidly than eggs which have not.

Ultrastructural changes in the avian vitelline membrane during embryonic development

Development ◽  
1969 ◽  
Vol 21 (3) ◽  
pp. 467-484
Author(s):  
Cynthia Jensen
Keyword(s):  
Embryonic Development ◽  
Mechanical Strength ◽  
Dual Role ◽  
Early Embryonic Development ◽  
Ultrastructural Changes ◽  
Vitelline Membrane ◽  
Entire Surface ◽  
Animal Pole ◽  
The Third ◽  
Vegetal Pole

The vitelline (yolk) membrane of the avian egg plays a dual role during early embryonic development; it encloses the yolk and provides a substratum for expansion of the embryo (Fig. 1). Expansion appears to be dependent upon the movement of cells at the edge of the blastoderm which is intimately associated with the inner layer of the vitelline membrane (New, 1959; Bellairs, 1963). The blastoderm (embryonic plus extraembryonic cells) has almost covered the entire surface of the yolk by the third and fourth days of incubation, and when this stage has been reached the vitelline membrane ruptures over the embryo and slips toward the vegetal pole. Rupture of the membrane during development appears to be the consequence of a decrease in its mechanical strength (Moran, 1936), which changes most rapidly at the animal pole (over the embryo).

scholarly journals Dynamics of Structural Barriers and Innate Immune Components during Incubation of the Avian Egg: Critical Interplay between Autonomous Embryonic Development and Maternal Anticipation

2018 ◽  
Vol 11 (2) ◽  
pp. 111-124 ◽  
Author(s):  
Maxwell T. Hincke ◽  
Mylène Da Silva ◽  
Nicolas Guyot ◽  
Joël Gautron ◽  
Marc D. McKee ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Innate Immune ◽  
Vitelline Membrane ◽  
Structural Barriers ◽  
Embryonic Tissues ◽  
Egg Incubation ◽  
Evolutionary Success ◽  
Protective Structures ◽  
Amniotic Membranes ◽  
Autonomous Development

The integrated innate immune features of the calcareous egg and its contents are a critical underpinning of the remarkable evolutionary success of the Aves clade. Beginning at the time of laying, the initial protective structures of the egg, i.e., the biomineralized eggshell, egg-white antimicrobial peptides, and vitelline membrane, are rapidly and dramatically altered during embryonic development. The embryo-generated extra-embryonic tissues (chorioallantoic/amniotic membranes, yolk sac, and associated chambers) are all critical to counteract degradation of primary egg defenses during development. With a focus on the chick embryo (Gallus gallus domesticus), this review describes the progressive transformation of egg innate immunity by embryo-generated structures and mechanisms over the 21-day course of egg incubation, and also discusses the critical interplay between autonomous development and maternal anticipation.

Studies of the Egg of Bacillus libanicus (Orthoptera, Phasmidae)

1950 ◽  
Vol s3-91 (14) ◽  
pp. 195-203
Author(s):  
A. MOSCONA
Keyword(s):  
Carbon Dioxide ◽  
Calcium Carbonate ◽  
Embryonic Development ◽  
Moisture Content ◽  
Mineral Content ◽  
Calcium Deficiency ◽  
Egg Shells ◽  
Egg Shell ◽  
Short Time ◽  
Initial Mineral

1. Weight, moisture content, and mineral content of freshly laid and of fully developed eggs of Bacillus libanicus (Uv.) were studied. During development of the embryo the egg-shell loses 19 per cent, of its initial mineral content, while the weight of mineral materials in the embryo increases correspondingly. 2. These changes can be explained only as resulting from transfer of minerals from the shell to the embryo. The mineral materials are derived from the calcium carbonate layer of the shell, which, owing to this loss, becomes thinner during embryonic development. 3. It is suggested that the mechanism of this transfer is based on the production of bicarbonate by the reaction of water and carbon dioxide, given off by the embryo, with the calcium carbonate of the shell. 4. Experimental calcium deficiency in the egg-shells results in a marked lowering of the viability of the embryos; although embryogenesis may sometimes proceed till the hatching stage, the few emerging nymphs survive only for a short time. 5. The possible occurrence of mineral transfer in other phasmid eggs is indicated.

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.

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