Restoration of retinal development in Vsx2 deficient mice by reduction of Gdf11 levels.

The visual system homeobox 2 (Vsx2/Chx10) gene is required for proper eye development in vertebrates. In mouse, mutations in Vsx2 cause micro-ophthalmia, optic nerve aplasia, and failed retinal development, as well as aberrant retinal lamination. GDF11, a member of the TGF-β superfamily of signaling molecules known to function as an autocrine negative regulator of sensory neuron neurogenesis, has also been shown to have dramatic effects on retinal development: Absence of Gdf11 results in an increase in numbers of retinal ganglion cells, resulting from changes in the fates of retinal stem/progenitor cells in Gdf11 null retinas. In the present study, we performed genetic manipulations of the GDF11 signaling system to determine whether alterations in Gdf11 activity levels can improve retinal development in Vsx2-null mice. We found that removal of Gdf11 alleles in Vsx2 orJ/orJ mice can rescue retinal development and thickness to a substantial extent, and partially restores the expression of genes important for the development of specific types of retinal neurons. The molecular mechanism(s) by which reduction of Gdf11 activity enables rescue of retinal development in Vsx2 mutant animals is currently being investigated, and should provide important insights for potential treatment of retinal dystrophies. © 2012 Springer Science+Business Media, LLC