develops from photoreceptor cell R2 CL:0000690 R2 lamina receptor cell R2 VFB:FBbt_00004215 https://cdn.ncbi.nlm.nih.gov/pmc/blobs/bae0/7069908/ef7abe34662d/359_2019_1375_Fig2_HTML.jpg fly_anatomy.ontology FBbt:00004215 FBbt:00003711 R2 The name photoreceptor cell R2 is occasionally, mistakenly assumed to refer to any Rh2 expressing photoreceptor cell. This is incorrect. This term only refers to a type of adult eye photoreceptor cell. The name is based simply on the position of the cell and its rhabdomere within each ommatidium - see figure 4 in Wolff and Ready, 1993. Cell connectivity was determined by analysis of semi-automated EM reconstruction of 749 serial sections of 21 complete lamina cartridges. The number of synaptic connections for R2 (presynaptic/postsynaptic) in a single lamina cartridge with each cell type was the following: L1 (43/-), L2 (45/1), L3 (10/-), L4 (-/1), Lai (39/-), T1 (2/-), Lawf (-/3), epithelial glia (13/-) and surface glia (1/-) (Rivera-Alba et al., 2011). Outer photoreceptor cell of the adult eye whose rhabdomere is located in the middle of the longer of the two parallel sides of the trapezoid of rhabdomeres in each ommatidium. It has a single axon that projects along a single lamina optic cartridge (Fischbach and Dittrich, 1989; Wolff and Ready, 1993). receptor cell R2 outer photoreceptor cell photoreceptor R2 precursor cell