Requirements for Regenerative Mechanisms in Tissue Growth and Homeostasis in Adult Zebrafish
- Authors
- Wills, A.A.
- ID
- ZDB-PUB-150626-31
- Date
- 2009
- Source
- Thesis : (Thesis)
- Registered Authors
- Wills, Airon
- Keywords
- Cell biology, General biology, Cardiogenesis, Epicardium, Fin, Regeneration, Zebrafish
- MeSH Terms
- none
- PubMed
- none
We found that regenerative capacity is generally required for homeostasis in the fin, as multiple genetic treatments that block regeneration also led to a degenerative loss of distal fin tissue in uninjured animals. In addition, we found that there is extensive cell turnover in the distal fin tissues, accompanied by expression of critical effectors of blastemal regeneration. Both cell proliferation and gene expression were sensitive to changes in Fgf signaling, a factor that is critical for fin regeneration.
In the heart, we found that although there is little cell turnover in uninjured adult animals, the zebrafish heart can undergo rapid, dramatic cardiogenesis in response to animal growth. These growth conditions induce cardiomyocyte hyperplasia similar to regeneration, and induce gene expression changes in the epicardium, a tissue that is critical for cardiac regeneration. We find that the epicardium continually contributes cells to the uninjured heart, even in the absence of cardiac growth. If this contribution is prevented via a long-term block of Fgf signals, scarring can result, indicating that continual activity of epicardium derived cells