DIPLOID AND TETRAPLOID CLONAL CELLS IN CULTURE - GENE PLOIDY AND SYNTHESIS OF COLLAGEN

Six subclones were derived from a single clone isolated from a strain of chromosomally stable rat fibroblast-like cells. Three of the subclones were diploid, three were tetraploid, and all were derived from a single somatic cell. Abnormal chromosomes or total chromosome numbers differing from multiples of haploid were not found. Measurements of rate of formation of hydroxyproline in protein from H3-proline, the accumulation of hydroxyproline in medium and cell layer with time, and the rate of incorporation of C14-leucine into protein that coprecipitates with collagen were employed to determine the rate of synthesis of collagen. By each of these measurements the rate of synthesis was found to respond directly to presumed ploidy of genes for collagen. © 1969 Plenum Publishing Corporation.