Changes in transfer RNAs and aminoacyl-tRNA synthetases during sea urchin development

Abstract

tRNAs from five stages of sea urchin development (eggs, two-cell stage, hatching blastula, middle gastrula and pluteus) were charged with four amino acids, using aminoacyl-tRNA synthetase preparations from the same stages of development. The aminoacyl-tRNAs were chromatographed on columns of benzoylated DEAE-cellulose. The elution profiles of arginyl-tRNAs from the five stages of development did not show significant differences. Small changes in the lysyl-tRNA patterns and the appearance of a new seryl-tRNA peak were observed during gastrulation. These effects are caused by alterations at the tRNA level. In the leucine system the tRNA elution pattern is altered very soon after fertilization or parthenogenetical activation of eggs. It could be shown that the alteration is due to a change at the synthetase level. This conclusion is based on cross experiments with tRNAs and synthetases from different stages of development and from yeast. It is supported by a number of control experiments.