12.00-12.15 Andreas Martin Sagner
‘Single cell transcriptomics reveals spatial and temporal dynamics of gene expression in the developing mouse spinal cord’
Transcriptional dynamics underlie cell fate choice and the establishment of cell identities. Single cell transcriptomics is emerging as a powerful tool to reconstruct the transcriptional dynamics along differentiation lineages with unprecedented resolution and to infer the molecular mechanisms underlying developmental progression. The advent of high-throughput single cell sequencing methods makes it possible to construct precise spatiotemporal atlases of gene expression of developing organs and even entire embryos. Here we present such a map for the developing mouse spinal cord based on transcriptome profiles of more than 20,000 cells from e8.5 to e13.5, which are assigned to specific classes of progenitors and neurons based on the expression of specific marker genes. This allows us to reconstruct the spatial and temporal dynamics of gene expression of the entire early spinal cord, including the identification of novel cell type specific markers and the de novo identification of novel neuronal subpopulations based on their transcriptional profile. We further identify and provide experimental evidence for the existence of a temporal transcriptional program that subdivides the neurons in the spinal cord based on their timepoint of birth. Our data therefore suggest that besides the well-known spatial patterning temporal mechanisms contribute to the generation of neuronal diversity in the spinal cord.