Identifying the Key Genes for Regeneration | HHMI BioInteractive (2017)

All multi-cellular organisms have a healing response. Most have the ability to regenerate lost body parts. Plants regenerate in fairly similar ways across diverse families. Animals on the other hand show a remarkable diversity. One can shred a sponge into pieces but the cells can rearrange and organize themselves in a surprisingly rapid manner. Human tissue and organ regeneration is a curious goal for medicine. However in order to achieve this one must understand whether there are common cellular and molecular mechanisms underlying all animal regeneration. Studying life forms that can and cannot regenerate may provide a useful comparison. For instance, although both are amphibians salamanders can regenerate but frogs cannot.

The free living flat worms called Planaria are famous for their amazing ability to regenerate lost body parts. Identifying the key genes involved in this process may offer clues into how regeneration works in animals. HHMI investigators at the Stowers Institute for Medical Research Alejandro Sánchez Alvarado and postdoctoral fellow Alice Accorsi, use RNA interference (RNAi) technique to silence beta-catenin and adenomatous polyposis coli (APC) genes.

Cephalization is an important characteristics in bilateral organisms. When the planarian beta-catenin gene gets silenced the animals regenerate two heads. Conversely, silenced APC gene leads to regeneration of two tails! Thus, the two genes are indeed masterswitches controlling regeneration. Studing other genes interacting with beta-catenin and APC will reveal the molecular pathways involved in this fascinating process.