Chd4 remodels chromatin to control retinal cell type specification and lineage termination

Area of Science:

• Neuroscience
• Developmental Biology
• Epigenetics

Background:

• Neural progenitor cells generate diverse cell types sequentially during development.
• Epigenetic regulation influences neural progenitor potential, but mechanisms remain unclear.

Purpose of the Study:

• Investigate the role of the nucleosome remodeler Chd4 in retinal development.
• Elucidate how Chd4 controls gene accessibility and transcription in neural progenitors.

Main Methods:

• Generated retina-specific conditional knockouts (cKOs) of Chd4.
• Utilized cut&run-seq and ATAC-seq for genome accessibility analysis.
• Performed multiplexed single-cell transcriptomics to assess gene expression.

Main Results:

• Chd4 cKOs showed overproduction of early-born retinal cells and underproduction of rod photoreceptors.
• Progenitors in Chd4 cKOs exhibited delayed Müller glia differentiation and prolonged proliferation.
• Chd4 deletion increased genome accessibility and transcription at thousands of regulatory elements.

Conclusions:

• Chd4 restricts the genome to repress progenitor identity and promote differentiation.
• Chd4-dependent nucleosome remodeling is critical for later temporal transitions, like lineage termination.
• Chd4 does not appear to regulate earlier temporal transitions in retinal progenitor development.