Description
Stem cell differentiation is known to involve changes in RNA expression, but little is known about translational control during differentiation. We comprehensively profiled gene expression during differentiation of embryonic stem cells (ESCs) into embyroid bodies (EBs) by integrating conventional transcriptome analysis with global assessment of ribosome loading. Differentiation was accompanied by an anabolic switch, characterized by global increases in transcript abundance, polysome content, protein synthesis rates and protein content. Furthermore, 78% of expressed transcripts showed increased ribosome loading, thereby enhancing translational efficiency. Elevated protein synthesis was accompanied by enhanced phosphorylation of eIF-4E binding protein, suggesting regulation by the mTOR pathway.