Comparative effects of mono-, di-, and triphosphorylated nucleosides on amphibian morphogenesis.

E X P E R I M E N T S previously reported (Ambellan, 1955) established the fact that short-term treatment of Rana pipiens blastulae with solutions of mononucleotides under specific conditions resulted in accelerated formation of neural tubes: at 18° C. they were about 4 hours ahead of controls. As briefly mentioned in the previous paper, slight overdoses or excessive periods of treatment resulted in visible side-reactions affecting other aspects of development in conjunction with the precocious neural tube formation. A comparison of the different effects that result from overdoses of adenosinemonophosphate (AMP-3), adenosinediphosphate (ADP), adenosinetriphosphate (ATP), and other compounds that differ from each other only in the number of phosphate bonds may throw some light on the biochemical nature of the morphogenetic processes differentially affected by these substances and is the subject of this paper.