Transcriptomics, regulatory syntax, and enhancer identification in mesoderm-induced ESCs at single-cell resolution

Area of Science:

• Developmental Biology
• Stem Cell Biology
• Genomics

Background:

• Embryonic stem cells (ESCs) possess the potential to differentiate into various functional cell types through defined developmental pathways.
• Understanding the molecular mechanisms governing ESC differentiation is crucial for regenerative medicine and developmental studies.

Purpose of the Study:

• To comprehensively catalog gene expression, histone modifications, chromatin conformation, and accessibility during ESC differentiation into presomitic mesoderm, and subsequently into myogenic and neurogenic lineages.
• To identify key cis-regulatory elements and transcription factors that orchestrate these lineage-specific gene-expression programs.
• To uncover previously unrecognized genomic elements involved in the activation of Pax7 and the initiation of myogenic and neurogenic programs.

Main Methods:

• Utilized bulk and single-cell assays to profile multiple molecular layers including gene expression, histone modifications, and chromatin accessibility.
• Analyzed transitions in ESC populations and individual cells undergoing lineage specification.
• Employed computational approaches to identify cis-regulatory regions and transcription factors.

Main Results:

• Detailed atlases of molecular changes during ESC differentiation toward mesoderm, myogenic, and neurogenic fates were generated.
• Identified specific cis-regulatory elements and transcription factors governing critical gene-expression programs at defined ESC developmental stages.
• Revealed significant heterogeneity within ESC populations at discrete developmental time points.
• Discovered novel genomic elements essential for initiating Pax7 expression and myogenic/neurogenic programs.

Conclusions:

• This study provides a valuable multi-omic resource for understanding the genomic and transcriptional landscape of pluripotent stem cells and their differentiated progeny.
• The findings offer insights into the complex regulatory networks controlling cell fate decisions during early development.
• The identified genomic elements and transcriptional regulators serve as potential targets for future research in stem cell differentiation and therapeutic development.