GSX2 Regulates Progenitor Maturation and Regional Identity Through Transcriptional Repression in the Developing Basal Ganglia [ATAC-seq]

Transgenic mouse models have demonstrated the critical role of the homeodomain transcription factor Genetic-Screened Homeobox 2 (??Gsx2) in the developing basal ganglia. However, the technical limitations of the existing in vivo approaches, such as progenitor heterogeneity and lack of temporal resolution, have impeded the investigation of direct regulatory targets . This study engineered a Dox-inducible human embryonic stem cell (??hESC) line to investigate the function of GSX2 protein in directed differentiation cultures that model developing lateral ganglionic eminence-like (LGE-like) progenitors. Transcriptomic, chromatin accessibility, and genomic binding studies revealed that GSX2: (1) binds to both high- and low-accessibility chromatin using varying binding site preferences; (????2) alters chromatin accessibility largely through indirect mechanisms; (3) functions primarily as a transcriptional repressor; and (4) regulates key conserved target genes of both progenitor maturation and regional specification. These results provide insight into the key regulatory roles and targets of GSX2, thereby establishing a new tractable experimental system to investigate basal ganglia development. Overall design: Triplicate, longitudinal ATAC-seq of chromatin state in transgenic H9 (WA-09) hESC line (TRE3G 2xFLAG-GSX2 WT) differentiated to LGE-like progenitors at Days 10-12 with variable transgene induction