Single cell analyses reveal the transient emergence of retinal progenitor cells in the ciliary margin zone during human retinal development [Spatial]
Retina is the innermost, light-sensitive layer that lines the back of the eye and is vital for light sensing and image processing. All the retinal cells types are derived from retinal progenitor cells (RPCs) in an orderly spatio-temporal manner that has been well studied in vertebrates. To better understand the emergence of RPCs, their localisation and differentiation to retinal lineages, we performed single cell (sc) RNA-Seq of 24 samples spanning 13 time points from 10-21 post-conception weeks of human development. Several types of progenitors were identified, including early and late RPCs which in turn gave rise the transient neurogenic progenitors that differentiated to all retinal neurones. Spatial transcriptomic analyses combined with scRNA-Seq revealed localisation of early RPCs in the ciliary margin of developing human retinas up to 10 PCW of development and propagation of neural retina differentiation from the centre to the periphery. Single cell ATAC-Seq analyses of 11 samples spanning 8-21 PCW of human development identified Hippo-Yap signalling as key pathway regulating RPC proliferation and cell cycle exit. These results provide the molecular map of human retinal development which may help guide generation of RPCs from human pluripotent stem cells and the design of cell-based replacement therapies for treating retinal dystrophies Overall design: 4 fetal retina samples from 8,10,11 and 13PCW