We studied the effects of dexamethasone on virus production and antigen expression in avian retrovirus-infected chick embryo fibroblast (CEF) cells. The presence of specific receptors for this hormone in both normal and infected CEF cells could only be demonstrated using cultures that were at or near confluence. Dexamethasone, while not toxic to the cells, exerted a growth-retarding influence w...

Extracellular matrices (ECM) isolated from chick embryo fibroblast and human and rabbit corneal stromal cells induce polarization and elongation of corneal endothelial cells in culture. ECM isolated from rabbit corneal or bovine aortic endothelial cells neither polarize nor elongate corneal endothelial cells in culture. By indirect immunofluorescence, fibronectin is seen as arrays of long fiber...

A ribonucleic acid (RNA)-dependent RNA polymerase was induced in chick embryo fibroblast cells after infection with Sendai virus (parainfluenza 1 virus). The enzyme was associated with the microsomal fraction of infected cells and reached maximum detectable activity at 18 hr after virus infection. The activity of the enzyme in vitro was dependent on the presence of added magnesium ions and all ...

Chick viability is known to be an important factor determining profitability of the poultry industry. Chick embryo tissues contain a high proportion of highly polyunsaturated fatty acids in the lipid fraction and therefore need antioxidant defence. The antioxidant system of the developing embryo and newly hatched chick includes the antioxidant enzymes (superoxide dismutase, glutathione peroxida...

We report here that cells present in embryonic chick retinal monolayer cultures express differentiated properties characteristic of chick cones developing in vivo. Cell suspensions from 8-d chick embryo retina (a stage when photoreceptor differentiation has not yet started) were cultured for up to 7 d in low density, glial-free monolayers. Under these conditions, monopolar cells represent appro...

Changes in lectin activity during development of embryonic chick skin were studied. In the dorsal skin of the chick embryo in which feathers were formed, lectin activity first increased, during the period of dermal condensation, and then it decreased during the development of feathers. A similar change in lectin activity was also found in the anterior shank skin, the prospective scale region of...