Control of phosphonic acid and phosphonolipid synthesis in Tetrahymena

The phosphonolipid content of the protozoan Tetrahymena pyriformis was increased by growing the organism on a medium containing increasing amounts of 2-aminoethylphosphonic acid. With levels of 0, 1, 5 and 10 mM 2-amino-ethylphosphonic acid, the phosphonolipid content was 23, 25, 31 and 37% of the total cellular phospholipids, respectively. This increase was accompanied by a reciprocal decrease in phosphatidylethanolamine. With 32Pi in the growth medium along with the 2-aminoethylphosphonic acid, the incorporation of the radioactivity into new molecules of 2-aminoethylphosphonic acid was almost totally inhibited, indicating a feedback control on phosphonic acid synthesis.