A West Virginia University biologist is delving into the genetic reasons behind why some animals can regenerate their bodies while others cannot.
Christopher Arnold, an assistant professor of biology at the WVU Eberly College of Arts and Sciences, is focusing on how genes that determine animal body plans may also influence regenerative abilities. His research could shed light on human development and disease, potentially offering new approaches to improve human health.
Arnold’s research is supported by a Maximizing Investigators’ Research Award from the National Institutes of Health. According to Arnold, the scientific community has much to learn about regeneration.
“We really don’t understand a lot about regeneration, and we have a bit of a misconception that regeneration is something super rare and that animals that can do it are out of the norm, particularly animals that regenerate their whole body,” Arnold said.
Highly regenerative animals are more common than previously thought, Arnold noted. Whole body regeneration could be an ancestral trait lost in some animal lineages, including humans, while retained in others. “To put it simply, those animals aren’t weird because they can regenerate. We’re weird because we can’t,” he said.
Regeneration appears to be more than simply a response to injury. The process may have other underlying factors. For instance, the human liver can regenerate to its original size even after 90% of the organ is removed, a degree of regeneration unusual in natural injuries.
Arnold emphasized the potential role of Hox genes, which are crucial for the patterning and evolution of various body plans across animals. These genes are highly conserved transcription factors that guide the embryonic development of animals from insects to humans. Several human developmental disorders and diseases are linked to Hox gene dysfunction.
“We have a fundamental set of genes for patterning the body,” Arnold said. “Our work has identified unexpected roles for these genes in a highly regenerative animal.”
Arnold’s subject of choice for this research is planaria, a flatworm known for its ability to regenerate its entire body both after injury and through asexual reproduction. “Planaria can asexually reproduce by tearing off pieces of their body, and each one of those pieces will be able to regenerate into a full copy of the parent organism,” he said.
These flatworms offer valuable insights as their Hox genes are essential for both asexual reproduction and maintaining whole-body regeneration. “We’ve never looked at this in these animals before,” Arnold noted. “We’re just starting to learn all the different ways these genes can create the diversity in the tree of life.”
Arnold’s work could pave the way for understanding why regenerative abilities vary across species, offering a deeper understanding of life’s complexities.
