Early stage differentiation of glia in human and mouse

Abstract

Central nervous system macroglia (astrocytes and oligodendrocytes) are required for normal brain development and function, and are among the last cells to emerge during neurodevelopment. Many questions remain about their emergence in the brain and spinal cord, including how early glial fates are specified during development or differentiation, and similarly when subtypes of glia are specified. Here, we used single-cell RNA sequencing (scRNAseq) to analyze ∼90,000 cells across multiple timepoints during the differentiation of astrocytes and oligodendrocytes from human induced pluripotent stem cells and mouse embryonic stem cells. Using time series analysis of gene expression, we uncovered multiple genes involved in fate specification of glial subtypes in both species. We examined gene expression changes during intermediate states of glial specification, and were able to identify genes that were correlated with the choice between neuron versus glia in both species. Using our scRNAseq data we optimized previous mouse astrocyte differentiation protocols by highlighting and removing non-required transition states and decreasing the overall protocol from 3 weeks to less than 12 days. Our data will be useful for researchers interested in optimizing glial differentiations in either species, and provide a window into human glial differentiation, which is difficult to study given its lateness in development.