This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: In a new Nature Physics study, researchers found that fin regrowth in zebrafish is driven by a brief burst of growth signal at the fin tip, sized to the amount lost, which sets up gradients of Erk activity that guide the regrowth. Unlike mammals, animals such as zebrafish and salamanders can regrow major appendages like limbs and fins after amputation.
The regrown structure matches the original in shape and size, with no stunting or overgrowth. This is known as positional memory. Size control is a fundamental biological aspect.
During normal development, limbs and organs are proportional to the body, and errors in size control can severely impair their function. Regeneration poses the same challenge. Researchers have identified many of the proteins needed to regrow a fin, but how they work together to restore the right size has remained a missing piece of the puzzle.
A leading idea has been that size information is stored in the fin before injury, for example, as a protein whose levels decrease along its length. While there is evidence for this in axolotl limbs, no such stored signal has been found in zebrafish. Phys.org spoke with co-authors Ashley Rich and Stefano Di Talia, both at Duke University Medical Center, and Ken Poss at the Morgridge Institute for Research and the University of Wisconsin–Madison.
"Understanding how positional memory is orchestrated at the cellular level inspired the recently published work," the researchers explained. A zebrafish's tail fin consists of 16 to 18 thin bony structures, called rays, separated by soft tissue. Each ray contains different cell types, including osteoblasts, the bone-building cells.
Each ray in an amputated tail fin grows independently. The rays that lose more tissue grow faster so that all of them return to their original length at roughly the same time. Regrowth begins with a layer of wound skin forming over the cut.
Extract — continue reading at the source.
