The chick embryo provides a superb vertebrate model that can be used to dissect developmental questions in a direct way. Its accessibility and robustness following surgical intervention are key experimental strengths. Mica plates were the first barriers used to prevent chick limb bud initiation1. Protocols that use aluminum foil as an impermeable barrier to wing bud or leg bud induction and or ...

Interferon-pretreatment of vaccinia-infected chick embryo fibroblasts resulted in a greater than 50% decrease in ribose methylation of the penultimate "cap" nucleotide in virus-specific mRNA. However, in contrast to results obtained with cell-free systems, in intact infected cells there was (a) no detectable reduction in methylation of the 5'-ultimate m7G of viral mRNA; (b) a virus specificity ...

The Dyche Museum at the University of Kansas: DR. Special Articles: ALEXANDER WETMORE .................... 593 The Protection of Mice Against Infection with AirSome Unsolved Problems of Theoretical Dynamics: borne Influenza Virus by Means of Propylene DR. GEORGE D. BIRKHOFF . 598 Glycol Vapor: DR. 0. H. ROBERTSON and OTHERS. Properties of the Isolated Macromolecular ComObituary: ponent of Norma...

These results show that primary chick embryo cells in culture release a particle bound RNA dependent DNA polymerase into the culture fluid. The enzyme is also found in the allantoic fluid of embryonated chicken eggs. This phenomenon is not restricted to the chicken system because primary quail embryo cells which are not known to express the so far known endogenous viruses release a particle bou...

Previous studies have implicated histone H5 dephosphorylation as a causal factor in genetic inactivation and chromatin condensation during erythroid senescence in adult chickens. We show that histone H5 phosphorylation declines in two stages as various cohorts of erythroid cells senesce in chick embryos. The first decline occurs between 5 and 6 days and coincides with the senescence of primitiv...

The chick embryo is a classic model that has been used to gain insight into developmental processes and cell fate within the embryo for over a century. For the most part, investigators have implanted quail cells into a chicken embryo. A more powerful tool for developmental biology research than the quail:chick chimera system would be to have lines of transgenic chickens expressing reporter gene...

VARIOUS malformations in rats and mice have been observed to be caused by administration of the vital dye, Trypan blue (Gillman, Gilbert, Gillman, & Spence, 1948; Fox & Goss, 1956, 1957; Hamburgh, 1952, 1954; Waddington & Carter, 1952, 1953). Recently Waddington & Perry (1956) reported a teratogenic effect of Trypan blue on Amphibian embryos. The present paper deals with the effects of this dye...

A study was made to establish the reproducibility of end points obtained in the titration of influenza viruses in chick embryos. Six tests were performed, each composed of five replicate titrations of a purified preparation of the PR8 strain of influenza virus. The data from these titrations were subjected to statistical analysis which revealed that the chances are 19 out of 20 that differences...

A method based on the familiar coupling azo dye technique has been devised for the study of enzyme distribution in thick specimens. Its application to the study of esterase distribution in whole tadpoles of Xenopus laevis is described in detail. It can also be used to show the distribution of alkaline phosphatase, both in Xenopus tadpoles and in limbs dissected from chick embryos. It has proved...