Single-cell analysis of human retina identifies evolutionarily conserved and species-specific mechanisms controlling development.

The advent of single-cell RNA-sequencing (scRNA-seq) has enabled high resolution studies of cell type diversity and transcriptional networks governing cell fate specification. In order to examine the transcriptional networks governing human retinal development, we performed scRNA-seq over retinal organoid and in vivo retinal development, across 20 timepoints. Using both pseudotemporal and cross-species analyses, we examined the conservation of gene use across retinal progenitor maturation and specification of all seven major retinal cell types. Furthermore, we examined gene expression differences between developing macula and periphery and between two distinct populations of horizontal cells. We also highlight both shared and unique gene usage during human and mouse retinal development. Finally, we identify an unexpected role for ATOH7 expression in regulation of photoreceptor specification during late retinogenesis. Together, these studies present a comprehensive atlas of gene expression during human retinal development; information vital for the modeling of both human retinal development and disease.