PROJECT SUMMARY There is a critical need to develop high-throughput scalable assays to identify biological mechanisms underlying risk genes in neurodevelopmental and neuropsychiatric disorders (NPD). In this proposal, we aim to leverage the unique advantages of two scalable systems – human induced pluripotent stem cells (hiPSCs) and zebrafish – to perform parallel functional assays of NPD genes in vitro and in vivo, and to pilot the development of innovative spatial multi-omics technologies applicable across systems. We propose to establish an Assay and Data Generation Center (ADGC) as part of the SSPsyGene Consortium that capitalizes on the unique and complementary expertise of our labs in large-scale hiPSC CRISPR screens (Brennand), high-throughput zebrafish screens (Hoffman), and cutting-edge multi-omics tool development (Fan). Our goal is to gain novel insights into the convergent and divergent mechanisms by which diverse NPD gene loss of function affects neurodevelopment at the molecular, cellular, structural, circuit, and behavioral levels. We propose to screen 250 NPD genes using a tiered strategy in hiPSCs and zebrafish by conducting pooled and arrayed transcriptomic and phenotypic screens in hiPSCs-derived neurons and glia (Aim 1), CRISPR screens in zebrafish to assess the effects of gene loss of function on whole-brain structure, activity, and basic behaviors (Aim 2), and spatial transcriptomic and multi-omic CRISPR screens to investigate the transcriptional effects of NPD gene disruption in both systems (Aim 3). We will advance the field by identifying biologically relevant phenotypes resulting from NPD gene loss of function across multiple scales, informing gene prioritization schema, and establishing new spatial multi-omics platforms for the functional analysis of NPD genes. These studies will generate an unprecedented resource of matched molecular, cellular, structural, circuit, and behavioral data in hiPSCs and zebrafish, which will be provided for open distribution to the broader community to yield new insights into NPD.