Studies of membrane, mammilary cores and cuticle of the hen egg shell

Cooke, A. S.; Balch, D. A.

doi:10.1080/00071667008415825

Cited by 42 publications

(13 citation statements)

References 15 publications

(21 reference statements)

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“…There are a number of histochemical studies on the membrane and oviduct wall particularly concerning the presence of complex carbohydrates [Robinson and King, 1967;Robinson, King and Bowen, 1968;Simkiss, 1968;Candlish, 1972]. However, recent chemical work has shown that the shell membranes contain at the most 5% carbohydrate [Cooke and Balch, 1970;Balch and Cooke, 1970;Candlish, 1972] and this seems to indicate that the contribution to membrane structure by complex carbohydrate molecules is considerably less than the histochemical studies had indicated. It also suggests that the specificity of some of the procedures may not be as high as has been believed; and this, coupled with slightly different preparative procedures and anatomical localizations, may explain some of the apparent discrepancies in the findings of the various groups.…”

Section: Discussionmentioning

confidence: 99%

“…The main protein, because it has a high content of cystine, was believed to be keratin, and indeed its possible keratin nature is still mentioned, if not assumed, in recent work on the shell membrane. However, hydroxyproline [Balch and Cooke, 1970] and hydroxylysine are now known to be present [Candlish and Scougall, 1969], which would seem to indicate the presence of collagen. Candlish [1972] believes that the insoluble cystine-containing acidic protein common to membranes, shell matrix, cuticle and vitelline membrane is a special structural protein, ovocapsin, with a marked propensity for cross linkage with other proteins such as collagen.…”

Section: Secretion Ofthe Isthmusmentioning

confidence: 99%

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THE FINE STRUCTURE OF THE FIBROUS MEMBRANE FORMING REGION OF THE ISTHMUS OF THE OVIDUCT OF GALLUS DOMESTICUS

et al. 1972

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The fibrous membrane forming region of the isthmus of the oviduct of Gallu8 Dome8ticu8 forms the upper two thirds of the anatomical isthmus. The secreting surface of the isthmus is arranged in a series of longitudinal ridges. The mucous membrane consists of a surface epithelium of columnar cells beneath which is a layer of tubular glands. In the membrane forming part of the isthmus the tubular gland cells are filled with prominent secretory granules, hence the name granular isthmus. The tubular glands of the lower third of the isthmus have few prominent granules and the region has a characteristic reddish tinge; hence the name red region of the isthmus is appropriate.In the granular isthmus there are three types of surface epithelial cell. Scott, 1935]. The red region adds water, potassium and glucose to the egg white and is involved in the initial nidation mechanism of calcification prior to the hard shell formation in the pouch of the shell gland [Draper, 1966;Davidson and Draper, 1969; Simkiss, 1968]. Richardson [1935] gives the total length of the isthmus as 8 cm in his hens and includes the red region as part of the shell gland. This has caused some confutsion in discussions of the contribution of the isthmus and the shell gland to the egg respectively.The primary object of this investigation is the study of the structure of the granular isthmus in relation to its production of the form and the substance of the shell membranes. Table I gives the status of each of the oviducts examined, and in all over 100 blocks were examined from the isthmus region. METHODSBirds were prepared for E.M. studies by giving a lethal injection of Nembutal Shell membranes for study were obtained from eggs midway down the granular isthmus (hens 12 and 13), from a soft egg in the proximal part of the shell gland (hen 14), and from laid eggs following removal of the hard shell. Tissues remained in fixative for 1-2 hr, were rinsed in buffer solution for 2-3 hr and then post-fixed in buffered osmium tetroxide for 14 hr. They were then rinsed in buffer solution and dehydrated through a series of alcohols commencing with 50% alcohol. Propylene oxide was used to clear the tissues which were then soaked in a mixture of propylene oxide and Araldite before the main immersion in Araldite. The tissues were embedded in Araldite in flat trays or propylene pre-shaped capsules. For location purposes, 2 ,um sections were cut from the Araldite blocks and stained by azure blue 11 in sodium borate solution using a hot plate to facilitate staining. Thin sections were cut on an L.K.B. ultrotome, mounted on uncoated grids and stained with uranyl acetate followed by lead citrate [Reynolds, 1963]. Specimens were examined with a Philips E.M. 200 electron microscope.For histological and histochemical studies, oviducts were removed from birds which had been killed with intravenous Nembutal. Each was transferred to ice cold Tyrode's solution, dissected free of ligaments and connective tissue and everted over strips of Perspex. After fixation in 10% buffere...

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Section: Discussionmentioning

confidence: 99%

Section: Secretion Ofthe Isthmusmentioning

confidence: 99%

THE FINE STRUCTURE OF THE FIBROUS MEMBRANE FORMING REGION OF THE ISTHMUS OF THE OVIDUCT OF GALLUS DOMESTICUS

et al. 1972

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“…If the acid mucopolysaccharide of shell matrix plays some part in calcification it seems unlikely, according to the experiments of Cooke and Balch (1970a) that acid mucopolysaccharide is concerned with the initiation of calcification. These workers concluded from the results of their analyses that the mamillary cores, the probable sites of the start of calcification, were devoid of acid mucopolysaccharide.…”

Section: Discussionmentioning

confidence: 95%

The hexosamine and uronic acid contents of the matrix of shells of eggs from pullets fed on diets of different manganese content

Longstaff

Hill

1972

British Poultry Science

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“…Such investigations are based upon the earlier findings of Cooke and Balch (1970), Simons and Wiertz (1963), Simons (1971), all of whom described the uneven distribution of the matrix throughout the shell and its arrangement of fibrils running parallel to the shell surface. With reference to its biochemical composition, Simkiss and Tyler (1957), acknowledged the matrix as a protein/acidic mucopolysaccharide complex and 23 years later Krampitz et al (1980), isolated a calcium binding polypeptide from eggshell called ovocalcin.…”

Section: The Organic Fractionmentioning

confidence: 99%

An egg ist ein ei, es un huevo, est un oeuf

Solomon¹

1999

British Poultry Science

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1. Many of the mechanical tests devised to measure shell quality are inadequate because they fail to recognise the complex interaction between the organic and inorganic aspects of the eggshell. 2. Twelve structural modifications have been observed at the level of the mammillary layer and their presence correlated with a variety of environmental stress events. Occurring as they do in the basal layers of the shell, these morphological variants influence its mechanical properties. 3. The organic matrix proteins which complex with the calcium carbonate derive from a variety of sites within the oviduct and vary in their location within the fully formed shell. In vitro mineralisation reveals the significance of these proteins in the crystal growth mechanism. 4. The isolation and identification of the protein moiety in well-structured eggshells is an essential prerequisite to understanding the abnormalities in crystal growth observed in the shells of older birds challenged by disease and other undesirable 'on farm' events. 5. The eggshell is the daily indicator of the bird's harmony with its environment and as such provides a readily accessible and non invasive measure of welfare. The integration of these data with those derived from behavioural and biochemical testing should provide industry with a reliable numerical welfare index.

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Studies of membrane, mammilary cores and cuticle of the hen egg shell

Cited by 42 publications

References 15 publications

THE FINE STRUCTURE OF THE FIBROUS MEMBRANE FORMING REGION OF THE ISTHMUS OF THE OVIDUCT OF GALLUS DOMESTICUS

THE FINE STRUCTURE OF THE FIBROUS MEMBRANE FORMING REGION OF THE ISTHMUS OF THE OVIDUCT OF GALLUS DOMESTICUS

The hexosamine and uronic acid contents of the matrix of shells of eggs from pullets fed on diets of different manganese content

An egg ist ein ei, es un huevo, est un oeuf

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