Genome-wide translation control analysis of developing human neurons

Spatiotemporal dynamics of the developing zebrafish enteric nervous system at the whole-organ level

Neural crest cells give rise to the neurons of the enteric nervous system (ENS) that innervate the gastrointestinal (GI) tract to regulate gut motility. The immense size and distinct subregions of the gut present a challenge to understanding the spatial organization and sequential differentiation of different neuronal subtypes. Here, we profile enteric neurons (ENs) and progenitors at single-cell resolution during zebrafish embryonic and larval development to provide a near-complete picture of transcriptional changes that accompany the emergence of ENS neurons throughout the GI tract. Multiplex spatial RNA transcript analysis identifies the temporal order and distinct localization patterns of neuronal subtypes along the length of the gut. Finally, we show that functional perturbation of select transcription factors Ebf1a, Gata3, and Satb2 alters the cell fate choice, respectively, of inhibitory, excitatory, and serotonergic neuronal subtypes in the developing ENS.

Ribosomal RNA 2'-O-methylation dynamics impact cell fate decisions

Translational regulation impacts both pluripotency maintenance and cell differentiation. To what degree the ribosome exerts control over this process remains unanswered. Accumulating evidence has demonstrated heterogeneity in ribosome composition in various organisms. 2'-O-methylation (2'-O-me) of rRNA represents an important source of heterogeneity, where site-specific alteration of methylation levels can modulate translation. Here, we examine changes in rRNA 2'-O-me during mouse brain development and tri-lineage differentiation of human embryonic stem cells (hESCs). We find distinct alterations between brain regions, as well as clear dynamics during cortex development and germ layer differentiation. We identify a methylation site impacting neuronal differentiation. Modulation of its methylation levels affects ribosome association of the fragile X mental retardation protein (FMRP) and is accompanied by an altered translation of WNT pathway-related mRNAs. Together, these data identify ribosome heterogeneity through rRNA 2'-O-me during early development and differentiation and suggest a direct role for ribosomes in regulating translation during cell fate acquisition.