Patterns of Synthesis of Thymidine Triphosphate and Other Deoxyribonucleoside Triphosphates in Mouse Liver and in Mouse Ascites Hepatoma.

The control of cellular proliferation in mam malian tissues is currently being investigated in terms of the basic biochemical processes leading to deoxyribonucleic acid (DNA) synthesis and the means by which critical steps in the biosynthetic sequence may be regulated by product interaction. Various enzymatic reactions involved in the syn thesis of DNA precursor substances have been ex amined in growing and nongrowing tissues, and although some relationships have been observed which are consistent with growth demands there is yet no indication of a critical point at which control is initiated or a mechanism by which this is effected. Bucher (2) has recently reviewed much of the biochemical literature on these aspects of DNA synthesis in relation to liver regeneration. Some time ago we began to approach the problem of control at the level of deoxyribonucleoside tn