Postdoctoral Research Fellow The Broad Institute of MIT and Harvard Cambridge, Massachusetts, United States
Abstract: Schizophrenia (SCZ) is a severe psychiatric disorder with a high amount of genetic heritability. Neurexin 1 (NRXN1) is a presynaptic cell adhesion gene linked to SCZ; however, individuals with copy number variants in NRXN1 display incredible phenotypic variability from being neurotypical to developing psychiatric or neurodevelopmental disorders, suggesting a contribution of genetic background. To study the influence of the same mutation in different genetic backgrounds, we developed “village editing” (CRISPR/Cas9 gene editing in a cell village format) and generated NRXN1 knockouts (KOs) in induced pluripotent stem cell (iPSC) lines from 15 donors with low, neutral, or high polygenic risk scores for SCZ. Using this method, we achieved high efficiency and recovered untargeted control clones as well as heterozygous (33.1%) and homozygous (28.4%) deletions in NRXN1 for most donors. We differentiated iPSCs to cortical excitatory neurons for 28 days with mouse glia and performed RNA sequencing to determine the effect of NRXN1 KO on neuron transcriptomes. We found that genetic background deeply influences gene expression changes in NRXN1 KO neurons. Ongoing studies are leveraging these tools to characterize NRXN1 function in neural cells, including examination of synaptic and other cellular phenotypes. In summary, we generated novel tools to examine NRXN1 function, demonstrate the importance of including multiple genetic backgrounds, and provide a framework for rapid and efficient development of similar tools to study gene functions in complex, polygenic disorders.
Funding Source: The Stanley Center for Psychiatric Research, National Institute of Mental Health U01MH115727 (RN), and National Institute on Aging K00AG068523 (RB)
