Regeneration of the sea anemone Nematostella vectensis: Dissecting the interplay between local and systemic responses

Animal regeneration describes the ability of animals to regrow a missing body part, such
as an arm or a tail. While we often think about regeneration to mean regrowth of limbs,
regeneration can also describe the regrowth of smaller structures (such as part of a nerve, or
part of an organ like the liver). Some animals are also able to regrow much larger structures.
For example, when the flatworm Planaria is cut into 279 little pieces, each piece is able to
regrow into a full worm again. This ability to reform an entire body from a small fragment
of tissue is called whole-body regeneration. This is the most impressive type of regeneration
because in this case, a very small bit of tissue is able to regrow all the different parts of the
whole body. How the small piece of tissue knows which body parts are missing and what the
body used to look like is still poorly understood.
The study of regeneration formally started in the mid 1700s. Scientists were captivated with
the ability of various animals’ ability to regrow missing body parts and sought to understand
how regeneration happens in these animals. The first animal to have its regenerative abilities
documented is the Hydra, a freshwater creature with a simple tube-like body with tentacles
extending from one end. Since the discovery of Hydra’s impressive regenerative abilities,
many animals have been found to be able to regrow body parts. Some of the most popular
animals used to study regeneration include a flatworm (Planaria), a small fish (zebrafish), and
a lizard (salamander). By studying how each of these animals are able to regrow lost body
parts, scientists have learned a lot about how wounding can lead to regeneration. However,
each of these animals has its shortcomings and limitations in terms of what scientists can
learn from them. Thus, new animals are still being introduced into the field of regeneration
to allow scientists to better understand the many factors involved in successful regeneration.
Nematostella vectensis, a small sea anemone, is one of these new animals being used to study
regeneration. This sea anemone is very simple but it still shares many genetic similarities with
humans. It is also very easy to work with and is capable of whole-body regeneration. Because
of these advantages, Nematostella became our animal of choice to study regeneration. During
my PhD I used this sea anemone to better understand how different parts of the animal
respond to injury and regeneration. Rather than focusing on only the regrowing body part, we
take a more holistic approach by looking at the entire body of the animal.