The Ciliary Margin Zone of the Mammalian Retina Generates Retinal Ganglion Cells

Cell Rep. 2016 Dec 20;17(12):3153-3164. doi: 10.1016/j.celrep.2016.11.016.

Abstract

The retina of lower vertebrates grows continuously by integrating new neurons generated from progenitors in the ciliary margin zone (CMZ). Whether the mammalian CMZ provides the neural retina with retinal cells is controversial. Live imaging of embryonic retina expressing eGFP in the CMZ shows that cells migrate laterally from the CMZ to the neural retina where differentiated retinal ganglion cells (RGCs) reside. Because Cyclin D2, a cell-cycle regulator, is enriched in ventral CMZ, we analyzed Cyclin D2-/- mice to test whether the CMZ is a source of retinal cells. Neurogenesis is diminished in Cyclin D2 mutants, leading to a reduction of RGCs in the ventral retina. In line with these findings, in the albino retina, the decreased production of ipsilateral RGCs is correlated with fewer Cyclin D2+ cells. Together, these results implicate the mammalian CMZ as a neurogenic site that produces RGCs and whose proper generation depends on Cyclin D2 activity.

Keywords: Cyclin D2; binocular vision; ciliary margin zone; contralateral RGCs; ipsilateral RGCs; neurogenesis; retina; retinal progenitors.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Differentiation / genetics
  • Cell Proliferation / genetics
  • Cilia / genetics
  • Cilia / metabolism
  • Cyclin D2 / genetics*
  • Humans
  • Mammals
  • Mice
  • Mice, Knockout
  • Neurogenesis / genetics*
  • Retina / embryology
  • Retina / growth & development
  • Retina / metabolism*
  • Retinal Ganglion Cells / metabolism*

Substances

  • Cyclin D2