Genes Required for GLP-1 Asymmetry in the EarlyCaenorhabditis elegansEmbryo

AbstractThe translation of maternalglp-1mRNA is regulated both temporally and spatially in the earlyCaenorhabditis elegansembryo (T. C. Evans, S.L. Crittenden, V. Kodoyianni, and J. Kimble,Cell77, 183–194, 1994). To investigate the control of embryonicglp-1expression, we have examined the distribution of GLP-1 protein in selected maternal effect mutants that affect pattern or fate in the early embryo. We find that mutants that disrupt anterior–posterior asymmetry in the early embryo (par-1–par-6, emb-8,Par(q537)) disrupt the spatial but not temporal control of GLP-1 expression: GLP-1 is observed at the normal stage of embryogenesis inpar-like mutants; however, it is uniformly distributed. In contrast, mutants that alter blastomere identity (skn-1, pie-1, mex-1, apx-1) do not affect the normal GLP-1 pattern. We conclude that genes controlling the asymmetry of cellular components, including P granules, also control GLP-1 asymmetry in the early embryo. The finding that mutants that disrupt anterior–posterior asymmetry translate GLP-1 in all blastomeres suggests that loss of embryonic asymmetry causes translational activation of GLP-1 in the posterior