CHAPTER 26 



The Metabolism of the Nucleic Acids 



R. M. S. SMELLIE 



Page 



I. Introduction 394 



II. The Use of P^^ in Studies on Nucleic Acid Metabolism 394 



1. DNA 394 



a. The Relative Activities of the DNA's from Different Tissues . . . 394 



b. The Effect of Physiological and Pathological Changes on the Uptake 



of Radioactive Phosphorus by DNA 395 



2. PNA 398 



a. Precautions Necessary in the Study of PNA Metabolism with P'* . 398 



b. The Relative Incorporations of Isotopic Phosphorus into the PNA 

 and DNA of Different Tissues 399 



c. The Uptake of P'* by the Individual Nucleotides Derived from the 

 PNA of Different Tissues 400 



d. The Effect of Physiological and Pathological Changes on the Metabo- 

 lic Activity of PNA 400 



III. The Metabolism of the Purine and Pyrimidine Bases of PNA and DNA. . 402 



1. General 402 



2. Small-Molecule Precursors of the Nucleic Acid Purines 402 



a. The Source of the Individual Atoms of the Purines 402 



b. Studies with Formate-C'^ 403 



c. Studies with C"- and C'*-labeled Glycine 404 



d. The Replacement of the Purine Nitrogen 404 



3. Labeled Adenine as a Precursor of PNA and DNA Purines 405 



4. The Metabolism of the Pyrimidine Bases 407 



IV. The Ribonucleic Acids of the Subcellular Fractions 408 



1. Contrast Between the Metabolism of Nuclear and Cytoplasmic PNA's . 408 



2. The PNA's of the Cytoplasm 411 



3. The Kinetics of PNA Metabolism 413 



V. Factors Affecting Nucleic Acid Metabolism 414 



1. The Effect of X-irradiation on Nucleic Acid Metabolism 414 



a. General 414 



b. The Effect of X-irradiation on the Uptake of Isotopes by the Nucleic 

 Acids of the Irradiated Tissue 415 



2. The Effect of Antibiotics on Nucleic Acid Metabolism 416 



a. Penicillin 416 



b. Aureomycin, Chloramphenicol, Neomycin, and Terramycin .... 418 



c. Bacitracin, Polymyxin, and Streptomycin 419 



VI. The Metabolism of Virus Nucleic Acids 419 



1. The Origin of Virus Nucleic Acids 419 



a. The Source of Bacteriophage Phosphorus 419 



b. Bacteriophage Nucleic Acids Studied with N'^ and C'"* 420 



2. The Fate of the Infecting Virus Particle .421 



393 



