Retina Regeneration in Zebrafish. In response to retinal damage or cell loss, zebrafish Müller Glia (MG) are activated and undergo dedifferentiation. Asymmetric division allows for self renewal and the generation of proliferating retinal progenitor cells (RPCs) which cluster along MG processes. As regeneration proceeds, the RPCs migrate to the site of damage before differentiating into any lost or damaged cell types.

Pathways and factors involved in retina regeneration. Following damage in the zebrafish retina, multiple pathways are activated controlling dedifferentiation of MG, re-entry into the cell cycle, asymmetric cell division, generation of proliferating RPCs, and eventual differentiation into replacement cell types. Green arrows represent factors that are active at the given step, whereas red arrows represent factors that are repressed or inactive at that time.

miRNAs and Retina Regeneration. The adult zebrafish retina expresses ~200 miRNAs but only a small subset of these miRNAs are differentially expressed during regeneration. RNAseq and other analyses after damage or during distinct stages of regeneration have identified miRNAs and select target mRNAs, as indicated. Green arrows represent miRNAs that are expressed or active at that given step, and red arrows represent miRNAs that are not expressed or inactive.