Ganglion cell regeneration following whole-retina destruction in zebrafish.

The retinas of adult teleost fish can regenerate neurons following injury. The current study provides the first documentation of functional whole retina regeneration in the zebrafish, Danio rerio, following intraocular injection of the cytotoxin, ouabain. Loss and replacement of laminated retinal tissue was monitored by analysis of cell death and cell proliferation, and by analysis of retina-specific gene expression patterns.

Embryonic retinal gene expression in sonic-you mutant zebrafish.

Hedgehog (Hh) signaling is required for proper eye development in vertebrates; known roles for Hh in the zebrafish include regulation of eye morphogenesis, ganglion cell neurogenesis, and photoreceptor differentiation. To gain insight into the mechanisms by which Hh signaling influences these developmental events, we have examined proliferation, cell death, and expression patterns of several retinal genes in the eyes of embryonic zebrafish lacking the sonic hedgehog gene. We find that features of the eye phenotype of the sonic-you (syu) mutant are consistent with multiple roles for the Hh signal during retinal development.