Utilization and requirements of amino acids by a cell line derived from the butterfly Papilio xuthus

The media, in which a butterfly cell line (Px 58), derived from pharate adult ovaries of Papilio xuthus cultured for 8 days, were analysed to examine the changes in free amino acids in the medium during cultivation. Beta-alanine, arginine, glycine, histidine, lysine, phenylalanine, proline, serine, and tryptophan did not change markedly. Asparagine, aspartic acid, cystine, glutamine, isoleucine, leucine, methionine, threonine, tyrosine, and valine decreased to some extent with culturing. Alpha-alanine increased markedly, and glutamic acid did so to a lesser extent. Requirements of amino acids by the cell line were examined by deleting amino acids one at a time. Deletion of alpha-alanine, beta-alanine, asparagine, glutamic acid, glycine, and phenylalanine did not cause deterioration of the cell. These amino acids were thought to be non-essential or required only a little. Deletion of other amino acids impaired the cell growth severely. These amino acids would appear to be essential for growth of the Px 58 cell line.