scholarly journals Effects of Male Accessory Sex Glands on Deoxyribonucleic Acid Synthesis in the First Cell Cycle of Golden Hamster Embryos1

1998 ◽  
Vol 58 (3) ◽  
pp. 659-663 ◽  
Author(s):  
Y. Ying ◽  
P. H. Chow ◽  
W. S. O
Keyword(s):  
Cell Cycle ◽  
Golden Hamster ◽  
Deoxyribonucleic Acid ◽  
Acid Synthesis ◽  
Accessory Sex Glands ◽  
Deoxyribonucleic Acid Synthesis ◽  
Male Accessory Sex Glands

Cell Proliferation in the Epithelium of the Oesophagus, Trachea and Ureter in Mice

1969 ◽  
Vol 5 (2) ◽  
pp. 393-401
Author(s):  
W. K. BLENKINSOPP
Keyword(s):  
Cell Cycle ◽  
Deoxyribonucleic Acid ◽  
Single Injection ◽  
Tritiated Thymidine ◽  
Acid Synthesis ◽  
Basal Cells ◽  
Paraffin Sections ◽  
Cell Cycle Time ◽  
Deoxyribonucleic Acid Synthesis ◽  
Intermediate Cells

Over a 24-h period, groups of mice were given a single injection of colchicine (to collect blocked metaphases) and tritiated thymidine (to label nuclei synthesizing deoxyribonucleic acid). Epithelial nuclei in the oesophagus, trachea and ureter were examined and counted in paraffin sections: the duration of deoxyribonucleic acid synthesis (Ts) was calculated from the numbers of blocked metaphases and labelled nuclei, the duration of the post-synthetic gap (TG2) was estimated from the proportion of blocked mataphases labelled, and the cell cycle time (Tc) was calculated from Ts and the proportion of nuclei labelled. In each epithelium the different layers seen by light microscopy were analysed separately. Ts was probably the same for the basal and superficial cells in the trachea (about 8 h), and was probably the same for the basal, intermediate and superficial cells in the ureter (about 5 h). In the oesophagus Ts was 8.5 h. TG2 was probably the same for the basal and superficial cells in the trachea (3.6 h), and probably the same for the basal, intermediate and superficial cells in the ureter (about 4.6 h). In the oesophagus TG2 was 2.8 h. Tc was about 380 h (basal cells) and 1400 h (superficial cells) in the trachea, and about 8000 h (basal and intermediate cells) and 2700 h (superficial cells) in the ureter. In the oesophagus Tc was 41 h.

scholarly journals THE TIMING OF DEOXYRIBONUCLEIC ACID SYNTHESIS IN THE CELL CYCLE OF SACCHAROMYCES CEREVISIAE

1965 ◽  
Vol 25 (3) ◽  
pp. 517-528 ◽  
Author(s):  
D. H. Williamson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Deoxyribonucleic Acid ◽  
Acid Synthesis ◽  
Dilute Acid ◽  
Deoxyribonucleic Acid Synthesis ◽  
Initial Appearance ◽  
Synchronized Cultures

Randomly dividing cultures of Saccharomyces cerevisiae were briefly exposed to radioactive adenine and then treated successively with dilute acid, ribonuclease, buffered formaldehyde, and NaOH. This treatment was shown to remove virtually all the radioactivity of the labelled cells other than that in DNA. Thus, in subsequent autoradiographs, only cells which had been synthesizing DNA during exposure to the precursor were labelled. The ages of these individuals within the cell cycle were estimated by measuring their sizes. This revealed that incorporation into DNA occurred almost exclusively during the first quarter of the cell cycle, starting with the initial appearance of the bud. This behaviour agreed closely with that of cells growing in artificially synchronized cultures.

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