Fig. 5: Mammalian orthologues of midget and parasol RGCs.
From: Evolution of neuronal cell classes and types in the vertebrate retina
a, Confusion matrix showing RGC clusters from different species that map specifically to oRGC1, oRGC4, oRGC5 and oRGC2, which contain OFF and ON midget RGCs (MGCs) and OFF and ON parasol RGCs (PGCs). Representation as in Fig. 3f. Column names corresponding to primate midget and parasol types are shown in red, and mouse α-RGC types are shown in blue. b, Schematic delineating morphological and physiological similarities between primate and midget RGCs and their α-RGC orthologues. Orthotypes (OTs) of each pair as well as the orthology among bipolar cell types that innervate them are also shown. Morphologies of neuronal types were created on the basis of published data (Supplementary Note 1). Within each pair, the left column corresponds to primate types and the right column corresponds to mouse types. c, FLDA projection of the scRNA-seq data for primate midget and parasol types and mouse α-RGC types onto the corresponding 3D space, with axes representing species, polarity and kinetics (see Supplementary Note 2). d, Matching MGCs and PGCs to mouse types by GAGE. Inset, given sets of mouse and primate RGC types, the model fits the arrangement of their cluster centroids in gene expression space by assuming a shape that is simply shifted to the other species via a linear translation. Symbols mark the four response types: circle, sustained; square, transient; open, ON; filled, OFF. The graph is a histogram of the fraction of explained variance showing for each proposed combination of four mouse cell types how well the resulting shape fits the macaque RGC geometry. The red bar shows the set of four α-RGC types. Green bars show combinations containing three α-RGC types. Grey bars, remaining sets of four mouse cell types as shown in Supplementary Table 4. e, Relative proportion of OFF and ON midget RGC orthologues in mammalian species based on frequencies of cells in oRGC1 and oRGC4.
