Dynamic landscapes of gene regulatory networks in early mammalian neurogenesis: Insights into brain evolution and disorder risk
Neurogenesis--the process of generating neurons--is governed by dynamic transcriptional programs that vary across time, brain regions, and cell types, forming regionally specialized neuronal circuits. To understand these dynamics, we constructed a comprehensive gene regulatory network (GRN) resource encompassing 22 neurogenic lineages from human, macaque, and mouse, enabling cross-species and cross-regional comparisons. Leveraging state-of-the-art trajectory analysis and GRN inference, we characterized temporal regulatory dynamics and introduced a "dynamic score" to identify key subnetworks with lineage-specific dynamics, including hundreds of regulons and co-regulatory modules. Our analysis uncovered both known and novel candidate regulators driving neuronal differentiation and regional identity, spanning the entire human brain, as well as evolutionary divergence in neurogenic GRNs distinguishing human brains. Mapping risk genes to the resource helped understand associated early gene regulatory dynamics with 35 neurodevelopmental disorders and traits including autism, schizophrenia, severe intellectual disability, and microcephaly. This resource is publicly available as an interactive online platform.