ABSTRACT
The dramatic development of eukaryotic genetics in recent years, however, will surely prove a great stimulus to studies of phospholipid biosynthesis in animal cells, as well as in yeast. The decision to concentrate first on the biosynthesis of phosphatidylcholine was obviously dictated by the fact that this is the predominant phospholipid of animal tissues, and by the fact that choline is so important in the diet of mammals in neurotransmission. The bacterial system has the intrinsic advantage of the higher rates of biosynthesis associated with very rapid growth, as well as benefiting from the remarkable development of bacterial genetics. Adenosine triphosphate (ATP) was needed in the system of Kornberg and Pricer at relatively high levels, giving rise to the suspicion that it might contain some active impurity. Crystalline ATP had just become available from commercial sources, and, through the kindness of Drs. S. A. Morrel, S. Lipton, and A.
