A GENETIC PATHWAY FOR REGULATION OF TRA-2 TRANSLATION

In Caenorhabditis elegans, the tra-2 sex-determining gene is regulated at the translational level by two 28 nt direct repeat elements (DREs) located in its 3' untranslated region (3'UTR). DRF is a factor that b inds the DREs and may be a trans-acting translational regulator of tra -2. Here we identify two genes that are required for the normal patter n of translational control. A newly identified gene, called laf-1, is required for translational repression by the tra-2 3'UTR. In addition, the sex-determining gene, tra-3, appears to promote female developmen t by freeing tra-2 from laf-1 repression. Finally, we show that DRF ac tivity correlates with translational repression of tra-2 during develo pment and that tra-3 regulates DRF activity. We suggest that tra-3 may promote female development by releasing tra-2 from translation repres sion by laf-1 and that translational control is important for proper s ex determination - both in the early embryo and during postembryonic d evelopment.