Single Cell Profiling in the Sox10^Dom Hirschsprung Mouse Implicates Hox Genes in Enteric Neuron Trajectory Allocation

Area of Science:

• Neuroscience
• Developmental Biology
• Genetics

Background:

• Enteric nervous system (ENS) development is crucial for gastrointestinal motility.
• Sox10 deficiency models Hirschsprung disease, causing aganglionosis and altered enteric neuron ratios.
• The precise mechanisms by which Sox10 deficiency impacts ENS development remain unclear.

Purpose of the Study:

• To investigate how Sox10 deficiency affects the development and differentiation of enteric neural crest-derived progenitors (ENCPs).
• To analyze the impact of Sox10 mutation on enteric neuron ratios and cell fate trajectories.
• To identify gene regulatory networks and specific genes involved in Sox10-mediated ENS development.

Main Methods:

• Immunohistochemistry to localize SOX10 protein in the developing ENS.
• Single-cell RNA sequencing (scRNA-seq) of ENS progenitors and neurons from Sox10 mutant and wild-type littermates.
• Analysis of scRNA-seq data for cell type identification, differential gene expression, and gene regulatory network (GRN) activity.
• Hybridization chain reaction (HCR) to validate gene expression changes.

Main Results:

• scRNA-seq identified three distinct neuronal trajectories and two transition pathways in the developing ENS.
• Sox10^Dom/+ mutants displayed a novel progenitor cell cluster and altered cell abundance across neuronal trajectories.
• Differential expression of Hoxa6 was observed in impacted neuronal trajectories in Sox10^Dom/+ mutants.
• HCR confirmed altered Hoxa6 expression in early developing neurons of Sox10^Dom/+ ENS.

Conclusions:

• Sox10 mutation alters enteric neuron types by modifying neuronal trajectories during early ENS development.
• Reduced expression of multiple neurogenic transcription factors was observed in Sox10^Dom/+ mutants.
• This study establishes a correlation between altered Hox gene expression, specifically Hoxa6, and changes in enteric neuron development.