USE OF AMINO-ACIDS BY PLASMODIUM-RELICTUM OOCYSTS INVITRO

A comparison was made of the in vitro growth of the gut of Culex tarsalis in Grace''s insect culture medium, supplemented with fetal bovine serum in the presence of dividing cells of Antheraea eucalypti, with a similar preparation of a gut infected with oocysts of the avian parasite P. relictum. In the latter case, after 16 h significant decreases occurred in the concentration of arginine, asparagine and glutamine combined, glutamic acid, glycine, histidine, lysine, proline and serine. Lower and less marked decreased concentrations of alanine, .beta.-alanine, cystine, isoleucine, leucine, methionine, ornithine, phenylalanine, threonine, tryptophan, tyrosine and valine took place. This indicated utilization of certain amino acids by the developing oocysts of P. relictum in the presence of metabolizing insect cells.