Ribosomal ribonucleic acid sites in chicken deoxyribonucleic acid.

Hybridization of ribosomal RNA from chickens with DNA immobilized on membrane filters indicated that the chick ribosomal genetic area represented less than 0.02% of the genome. Competition of ribosomal RNA from differentiated tissues suggested that the same ribosomal RNA population was expressed by the cells of each tissue, including spleen cells grown in tissue culture. A saturation RNA/DNA ratio of 0.2% was found for Escherichia coli ribosomal RNA which confirmed reported values. Ribonucleic acid recovered from the hybrid was identical in base ratio to the starting RNA. Compared to the E. coli system, the hybridizing efficiency of chick ribosomal RNA was low and the base ratio of the recovered hybridized RNA indicated some susceptibility of the complex to ribonuolease attack.