An improved CRISPR-LICHT screen of 120 Tdark genes illuminates new biologically relevant SOX2 targets in human brain organoids

CRISPR-LICHT screening of 120 Tdark SOX2-dependent genes in human cerebral organoids identified 28 candidate hits whose disruption impaired neural progenitor lineage expansion and/or survival.

• Why it matters: SOX2 is a key neural progenitor regulator, but its downstream human developmental networks are incompletely mapped beyond severe microcephaly-associated phenotypes.
• What they did: The study used CRISPR-lineage tracing at cellular resolution (CRISPR-LICHT) in heterogeneous human cerebral organoids with a SOX2-focused library, then screened 120 evolutionarily conserved Tdark genes.
• The result: Hits included genes tied to cytoskeletal organization, membrane dynamics, and intracellular architecture; CDC42EP4 downregulation altered targeted progenitor distribution between ventricular- and subventricular-like compartments.