This regulation resembles the antero-posterior control of hunchback mRNA in Drosophila, and could underlie a fundamental system for generating polarity in the early embryo. To determine the relevance of the NRE-like motifs, we have further examined sequence requirements. A 39 nt deletion that removes all three NRE-like motifs and intervening sequences prevented posterior repression, whereas removal of a neighboring 21 nt had no effect. In addition, replacement of the intervening sequences with random sequence of the same base composition had no effect on regulation. Preliminary experiments suggest that glp-1 mRNA lacking translational control elements in the 3' UTR induces embryonic lethality in wild type embryos.
Dead embryos contain many differentiated cell types but fail to undergo proper morphogenesis.
Thus, derepression of glp-1 translation may lead to specific lineage alterations in the embryo. In addition we plan to determine the lineage defects.