Planarians have an amazing ability to regenerate lost tissues. In this video, scientists knock out two different genes in planaria to start to understand how the process works—and they generate animals with two heads and two tails!
Note: This video is available in both English and Spanish versions, both with original narration by Alejandro Sánchez Alvarado.
Identifying the key molecular players in planarian regeneration may offer clues into how the process may work in other species, including humans. HHMI investigator Alejandro Sánchez Alvarado and postdoctoral fellow Alice Accorsi, both at the Stowers Institute for Medical Research, use RNA-mediated genetic interference (RNAi) to silence different genes in planaria and determine how they affect regeneration.
In this video, we see the results of their RNAi experiments with two key genes: beta-catenin and APC. Normally when you amputate a planaria’s head and tail, stem cells in the animal’s body will migrate to the sites of the cuts and differentiate into a new head and tail in the correct places. But when Sánchez Alvarado and Accorsi treated animals with RNAi specific for beta-catenin, the planaria regenerated two heads, and when they treated them with RNAi specific for APC, two tails. Repeating this process for other genes will help the scientists build the molecular pathways involved in regeneration, which may also be activated in humans.