SoxB1-Mediated Chromatin Remodeling Promotes Sensory Neuron Differentiation in Planarians

Area of Science:

• Developmental Biology
• Stem Cell Biology
• Regenerative Medicine

Background:

• Adult stem cells generate neurons, crucial for regenerative medicine.
• Planarian flatworms offer a model for studying adult neurogenesis due to abundant stem cells (neoblasts).
• SoxB1 transcription factors are involved in ectodermal lineage commitment, with planarian SoxB1-2 promoting neural and epidermal differentiation.

Purpose of the Study:

• Investigate the mechanisms by which SoxB1-2 influences chromatin dynamics and gene expression during adult neurogenesis.
• Understand the role of SoxB1-2 in adult stem cell fate specification.
• Identify downstream targets of SoxB1-2 in neurogenesis.

Main Methods:

• Performed ATAC-seq and RNA-seq on neural-rich planarian head tissues.
• Utilized RNA interference (RNAi) to knock down soxB1-2 expression.
• Analyzed changes in chromatin accessibility and gene expression following soxB1-2 disruption.

Main Results:

• Disrupting soxB1-2 led to reduced chromatin accessibility and gene expression in neural and epidermal cells.
• SoxB1-2 acts as a pioneer factor, priming chromatin for differentiation.
• Identified 31 downstream targets, including castor and mecom, involved in mechanosensory and ion transport.
• Detected soxB1-2-responsive genes in rare neural subtypes missed in previous whole-body studies.

Conclusions:

• SoxB1-2 plays a critical pioneer-like role in adult neurogenesis by regulating chromatin accessibility and gene expression.
• Findings provide mechanistic insight into adult ectodermal lineage specification.
• Establishes a framework for studying chromatin-mediated neurogenesis in regenerative systems.