part of part of has part has part retinal progenitor cell cell layer retina ciliary marginal zone Region at the periphery of the retina where retinal stem cells are located. After 60 hpf, the CMZ is the source of most retinal growth.[Wehman et al, 2005]. XAO:0000086 EFO:0003668 peripheral growth zone CMZ VHOG:0000088 retinal ciliary marginal zone circumferential germinal zone AAO:0010342 The retina of all vertebrates develops via similar mechanisms. Toward the end of retinal histogenesis, proliferating progenitors and newly generated cells are confined to peripheral regions of the retina. In fish and amphibians, this region is maintained after embryonic development and becomes the CMZ (ciliary margin zone). A CMZ exists in birds but compared to that of fish and amphibians this region produces much less new retina as the globe of the eye expands postnatally. At least some of the molecular mechanisms that regulate the addition of new cells in this zone appear to have been conserved from fish to birds.[well established][VHOG] Region at the periphery of the retina where retinal stem cells are located. After 60 hpf, the CMZ is the source of most retinal growth. Wehman et al, 2005.[TAO] TAO:0001289 UBERON:0003065 ZFA:0001289 retinal proliferative zone