Lipids in the egg shell of the ostrich (Struthio camelus) (author's transl)]

The egg shell (with cuticle) of the ostrich contained a total lipid concentration of 0.19 mg/g egg shell; the phospholipids constituted the major portion, among the neutral' lipids cholesterol esters, cholesterol and free fatty acids were identified. The egg shell lipids showed a stimulating effect on the crystal growth of calcium carbonate; the highest rate of crystal growth was observed with the phospholipid fraction.     

Possible relationship between packed sperm volume and egg mass in domestic fowl

Summary Packed sperm volume (PSV) values of male chickens have been observed to parallel the daily egg mass values of laying hens. Selection progress was greater when selection was for PSV and egg mass than for egg mass alone.     

The egg-lipid composition of the ‘living fossil’ reptile tuatara (Sphenodon punctatus)

Summary The lipid composition of two tuatara eggs was examined. The eggs contained triacylglycerol (80%) and phospholipid (12%) as their major lipid fractions. Fatty acid analyses of the individual lipid classes indicated the presence of essential fatty acids, linoleic and arachidonic acids. The quantity of such acids in the egg yolk lipids would suggest they are factors for survival as illustrated in other species.     

pH and calcium concentration changes in a molluscan egg during development.

During development, the egg albumen of calcified land snail eggs becomes more and more acid, correlated directly with a constant rise in the calcium concentration of this albumen. It is suggested that the developing embryo releases some acid metabolite and the subsequent change in albumen pH aids in embryonic absorption of the CaCO3 (calcite) egg shell, used for making the embryonic body shell or skeleton (CaCO3 in the form of aragonite).     

Zum Schlüpfprozess bei Fischen: I. Der Aufbau der Eihülle und ihre Veränderungen während der Keimesentwicklung bei der Forelle (Salmo trutta fario L.)

Summary The investigation of the egg shell ofSalmo trutta fario L. reveals several layers, which are chemically and physically different. During development of the egg, the chorion does not show notable changes in structure. Immediately at hatching the dissolution of the egg takes place as a result of the glands being on the head of the embryo.

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FräuleinBarbara Blum danken wir für ihre technische Hilfe.

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Der Deutschen Forschungsgemeinschaft sei für finanzielle Unterstützung gedankt.     

Enzymes involved in oxygen detoxification during development of Drosophila melanogaster

Activities of superoxide dismutase (SOD), catalase (CAT), and peroxidases (PER) were examined at 24-h intervals during Drosophila development. SOD activities show a U-shaped curve from egg to adult stages whereas CAT and PER are consistently low in egg through larval stages. Male and female larvae have similar activities of SOD, CAT, and PER whereas male adults have elevated activities of these enzymes. Larvae are more sensitive to H2O2 and 3-amino-1,2,4-triazole (an inhibitor of CAT) than adults.     

pH and calcium concentration changes in a molluscan egg during development

Summary During development, the egg albumen of calcified land snail eggs becomes more and more acid, correlated directly with a constant rise in the calcium concentration of this albumen. It is suggested that the developing embryo releases some acid metabolite and the subsequent change in albumen pH aids in embryonic absorption of the CaCO₃ (calcite) egg shell, used for making the embryonic body shell or skeleton (CaCO₃ in the form of aragonite).     

Parental care in terrestrial gastropods

Parental care in terrestrial gastropods includes the of oviposition sites, production of large, heavily-yolked eggs supplied with calcium carbonate, provisioning of hatchings with eggs in specis with facultative sibling cannibalism, egg retention, and ovoviviparity. Evidence for true viviparity is scarce in terrestrial gastropods, as it is for postlaying care of eggs, though external egg carrying on the shell occurs in a few species. Care of young has not been observed in any terrestrial gastropod species. Provisioning of eggs with nutrients and calcium carbonate might be the most common form of parental investment. Ovoviviparity allows terrestrial gastropods to persist in habitats otherwise unsuitable for oviparous species (e.g. exposed rock walls). An interspecific comparison demonstrates that egg-retaining and ovoviviparous species produce smaller clutches than oviparous species and suggests a cost of parental care.     

Biotin-binding proteins in eggs of oviparous vertebrates

Summary Biotin-binding was found in the egg whites and yolks of all 23 avian species studied, and in a turtle, but the amount varied considerably even in related species. There was no clear correlation in biotin-binding between egg white and yolk in various species. Antigenic determinants of avidin in different species have changed in the course of evolution as compared with those of chicken egg white avidin.We thank Mr Jukka Peltonen and Mr Antti Karlin for the collection of the avian eggs with permission obtained from the Ministry of Agriculture, and Mr Reino Saarinen for the turtle eggs. The authors are indebted to Mrs Outi Kurronen Miss Riitta Mero and Miss Tiina-Maija Mattila for technical assistance. This work was supported by the Ford Foundation Grants No. 760-0526 and No. 790-0665.     

Common antigenic properties of a g-type (goose) and a c-type (duck) egg white lysozyme: Antibody responses in rabbits and mice

Embden goose (GEWL) and Barbary duck (DEWL) egg white lysozymes possess different amino acid sequences corresponding to the g-type and c-type, respectively. GEWL was shown to be a better immunogen than DEWL in both rabbits and mice. The antigenicity of the two lysozymes was tested using different technique (i.e. indirect ELISA, inhibition tests and immunoabsorption experiments). Injection of either GEWL or DEWL into rabbits and mice induced both specific antibodies and cross-reacting antibodies. Moreover, anti-GEWL antibodies, in contrast to anti-DEWL antibodies, did not cross-react with hen egg white lysozyme (HEWL), a c-type lysozyme. While the structure of GEWL was not modified after binding to plastic, DEWL was denaturated, but it did keep some native epitopes. It was concluded that g-type and c-type lysozymes, which have different amino acid sequences, exhibit strong common antigenic properties.