Abstract
Presentation Description :
The retina generally contains six major neuronal classes: cone and rod photoreceptors (PR), horizontal cells (HC), amacrine cells (AC), bipolar cells (BC), and retinal ganglion cells (RGCs); and one main glia, müller glia (MG). The six neuronal types are organized into three somatic layers and formed synaptic connections within two synaptic plexiform layers. The laminar organization of retinal cells is shared among species, yet the visual perception is highly diverse. For example, human and most primates have the highest acuity vision among mammals. The high visual acuity in primates stems from the fovea, a specialized region in the center of retina. In this study, we ask to what extent does the fovea differ from the periphery, and primate retina differ from mouse retina by retinal cell types and gene expression.
To systematically address these questions, we used single-cell RNA-seq profiling to gain molecular characterizations of cell types to investigate their conservation and divergence. We analyzed >165,000 single-cell RNA-seq (scRNA-seq) profiles from the fovea and peripheral retina of adult crab-eating macaques (Macaca fascicularis), a widely used primate model in vision studies. We identified and molecularly characterized >65 cell types in each region, providing novel molecular markers for most types, and validated many by pairing them with cell morphology. We used a comparative analytic framework to match cell types between the fovea and the periphery, showing that the two regions share a common repertoire of types, but exhibit marked differences in cell type proportions and cell-intrinsic expression programs, which likely mediate their functional differences. We then assessed the conservation of macaque retinal cell types with those in other species. We found a tight correspondence between mouse and macaque PRs, BCs and ACs, but a divergence in RGC types, despite a conserved transcription factor code. Key macaque types and molecular features are also conserved in marmosets and humans.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.