Changes in elongation factor-1 alpha transcripts are uncoupled to changes in EF-1 delta during sea urchin development

A probe for Sphaerechinus granularis EF-1 alpha mRNA was generated and sequ enced, and further used for comparative developmental analysis of gene expr essions of two components of elongation factor-1, EF-1 alpha and EF-1 delta . EF-1 alpha mRNA, detected as a single 2.7 kb transcript decreased 6 h aft er fertilization and dramatically increased 20 h post-fertilization at the late blastula stage. The relative ratio of EF-1 alpha versus EF-1 delta tra nscripts varied from 0.2 up to 10 (x 50) during development, thus demonstra ting uncoupling in the genetic expressions of the two EF-I components durin g the rapid cell divisions following fertilization and in the slow cell cyc le period of later development. ((C) Elsevier, Paris).