Table 2.

Factors affecting progenitor cell cycle exit and differentiation in zebrafish.

Factor	Normal function	Method of reduction	Effect on progenitor cell cycle exit	Effect on progenitor migration	Effect on progenitor differentiation	Ref
Drgal1-L2 (Igals2a)	Galectin family member, β-galactoside binding protein	Morpholino knockdown	None noted	None noted	Stimulates rod regeneration	99
FGFR	Signal transduction	Dominant/negative	*None noted	None noted	*Photoreceptor maintenance and rod regeneration	115,123
Insmla	Transcriptional repressor	Morpholino Knockdown	Stimulates cell cycle exit	Stimulates migration into ONL	Stimulates differentiation	96
Mps1	Mitotic check point regulation	Temperature sensitive mutation	None noted	None noted	Stimulates cone differentiation	12
N-cadherin	Cell adhesion	Semi-dominant mutation	None noted	Progenitors accumulate in ONL	Necessary for regeneration of inner retinal neurons	13
Notch	Signal transduction	Pharmacological inhibition; NICD overexpression	!None noted	None noted	Stimulates photoreceptor differentiation at the expense of MCillerglia differentiation	83

^*One study reports no effect of dnfgfr on progenitor proliferation following light damage and that fgf signaling is necessary for rod maintenance¹¹⁵, while the other study shows dnfgfr suppresses progenitor proliferation following light damage and that fgf signaling is necessary for rod and cone maintenance¹²³.

^!Notch signaling inhibits progenitor formation and proliferation in the injured retina⁸³.