Biology of tissue

Retina regeneration in zebrafish depends on the reprograming ability of theMuller glia into a proliferating population of retinal stem cells. Severalregeneration-associated genes and pluripotency-inducing factorssuch as Oct4, cMyc, Lin28, Sox2, Lin28 etc contribute to this reprogramming. Many developmentally essential pathways such as Wnt, Notch, Shh, and Tgf-β signalling govern the timely induction and decline of various pluripotency-inducing factors and regeneration-associated genes. Epigenome modifiers such as polycomb repressor complex, histone deacetylases and non-coding RNAs such as miRNA let-7, and lncRNA malat1 also contribute to the complex cascade of regeneration events. Many retina regeneration pathways play similar roles during the regeneration of other tissues such as zebrafish fin and axolotl limb/tail. Immune cells migration to the injury site also plays a vital role to cause adequate build up of extracellular matrix during tissue regeneration.
Taken together, the insights from zebrafish and axolotl regeneration studies bring us closer to mammalian complex tissue regeneration.