Regeneration of Organs and Appendages in Zebrafish: A Window into Underlying Control Mechanisms

Abstract The ability to regenerate organs and appendages is not universal among animals. Humans have a rather limited capacity to regenerate after injury, while other vertebrates such as the zebrafish are capable of regenerating many anatomical structures. Research with the zebrafish indicates that different structures use different regeneration strategies: fin regeneration involves the formation specialised epidermis and the accumulation of blastemal cells at the amputation site. Regeneration of nervous system tissues utilises the activation of resident stem cells, whereas the regeneration of heart muscle appears to employ the proliferation of differentiated cardiomyocytes. This article details how zebrafish appendages, nervous tissues and heart regenerate and how current cell and molecular discoveries from these regenerating fish structures contribute to our understanding of general principles of regenerative biology. Key Concepts: The zebrafish is a remarkable in vivo model to understand the cell biology and molecular mechanisms required for appendage and organ regeneration. Studying how the zebrafish regenerates its fins, its nervous system and heart will provide information on how endogenous cell populations (whether fully differentiated or stem cells) are reprogrammed to form progenitor cell populations that concertedly regenerate compound structures.