mRNA-binding proteins repress mRNA translation to determine cell lineages

Translational regulation and cell-lineage decisions in the early C. elegans embryo. (a) At the four-cell stage of the C. elegans embryo, the GLP-1 protein is expressed in two anterior cells (bright green) but not in other cells. Translation of the glp-1 mRNA is regulated by the GLD-1 protein in posterior cells. (b) Fusion of the glp-1 3 ‘ UTR to the lacZ reporter gene leads to reporter expression in the ABa and ABp cells of the four-cell stage of the C. elegans embryo (shaded, right). Mutations in GLD-1-binding sites in the spatial control region (SCR) cause derepression of translation in the EMS and P₂ lineages, as does (c) loss of gld function.

[(a) Courtesy of Thomas C. Evans, University of Colorado Anschutz Medical Campus.]