ELUTION PROFILES OF LYSINE AND TYROSINE TRANSFER RNA DURING AVIAN DEVELOPMENT

Changes in the reversed-phase chromatography patterns of the isoaccepting species of 13 aminoacyl-tRNA's during avian development were investigated. Only lysyl- and tyrosyl-tRNA's from whole chick embryo showed altered profiles when compared to the corresponding tRNA's from individual adult chicken organs. At least 3 species of lysyl-tRNA were found. The distribution of lysyl-tRNA radioactivity in whole chick embryo profiles was 12, 50, and 38 % for Peaks I, II, and III, respectively. The corresponding values for adult liver were 4, 50 and 46 %. No effect on these distributions was observed when liver enzymes were used to charge both liver and embryo tRNA. The changes for lysyl-tRNA were observed in 4-, 8- and 20-day-old chick embryos. Similar variations of lysyl- and tyrosyl-tRNA's in duck embryos were absent. When lysyl-tRNA was chromatographed on benzoylated DEAE-cellulose columns, Peak I of chicken liver and whole chick embryo did not coincide. An additional peak was also detected, for both samples, in the ethanol salt wash. When lysyl-tRNA prepared from either the subcellular or soluble cell fraction of adult liver was chromatographed, with lysyl-tRNA of the corresponding whole embryo fraction, the same differences for Peak I were found.