Aligning Single-Cell Developmental and Reprogramming Trajectories Identifies Molecular Determinants of Myogenic...

Area of Science:

• Cell Biology
• Developmental Biology
• Systems Biology

Background:

• Cellular reprogramming aims to generate specific cell types for therapy and understand gene regulation.
• Current reprogramming methods often suffer from low efficiency, converting only a small proportion of cells.

Purpose of the Study:

• To analyze the barriers to efficient cellular reprogramming using a well-established model system.
• To develop and apply a novel analytical technique for comparing gene expression kinetics during biological processes.

Main Methods:

• Utilized single-cell RNA sequencing (scRNA-seq) to analyze MYOD-mediated reprogramming of human fibroblasts to myotubes at pseudotemporal resolution.
• Introduced and applied a novel analytic technique, trajectory alignment, for quantitative comparison of gene expression kinetics.

Main Results:

• Identified branch points in the reprogramming trajectory corresponding to critical cell fate decisions.
• Discovered that insulin and BMP signaling pathways are crucial molecular determinants controlling reprogramming efficiency and outcome.
• Demonstrated that incorrect cell fate choices lead to aberrant or incomplete reprogramming.

Conclusions:

• Single-cell trajectory alignment is a powerful tool for quantitatively comparing biological trajectories across different processes.
• Understanding signaling pathway dynamics is essential for improving cellular reprogramming efficiency.
• This approach can be applied to diverse biological processes, including development and reprogramming.