Effects of lysine deprivation and serum stimulation on the synthesis of non-histone chromosomal proteins by confluent chick fibroblasts

Cellular sterol content and sterol metabolism were studied in diploid human kidney cells in early passages in culture. Cholesterol, the main cellular sterol, was present at levels similar to those reported for other cultured mammalian kidneys. Cholesterol biosynthesis was characterized by a slow conversion of sterol precursors with accumulation of lanosterol and 27 carbon-atom sterols. In the absence of exogenous cholesterol, kidney cells grew slowly and intracellular cholesterol decreased; however, sterol formation from labelled acetate was stimulated. These results suggest that the cholesterol concentration in the culture medium influences the rate of sterol formation by the kidney cell. Furthermore, cholesterol appears to be essential to cultured human kidney and de novo synthesis by the cells in culture is not adequate to meet their requirements for growth.     

Properties of soluble chromatins isolated from apical and axial parts of cauliflower inflorescence

Soluble chromatins were isolated from apical and axial parts of the cauliflower inflorescence. The template activities of the two chromatins were found to differ significantly, when using RNA polymerase of Escherichia coli. The derivative thermal melting profiles showed at least three melting peaks for each chromatin, indicating that higher T_m values could be distinguished in the apical chromatin in each peak. Histones extracted from both chromatins were analysed by acrylamide disc-electrophoresis. A much smaller amount of presumed F1 fraction was observed in the sample from axial chromatin.