Earwig close-up
What animals first come to mind when thinking of scientific research? Mice, rabbits and chimpanzees, right? You probably didn’t think of earwigs, did you? Well maybe now you should. Dr. Judith Roe and two of her students–Sabrina Douglas and Ashley Rekem–are currently conducting research in making earwigs into a model system for organ regeneration right here on campus at UMPI. Maine INBRE is funding the project as the organization’s goal is to research opportunities in the biomedical field in Maine.
What is a model system? In biology, it’s a plant or animal that can be easily bred, maintained and studied in a lab setting.
“A model system would be a system we can study in the laboratory that might give us a clue about how organ regeneration works in many organisms, not just earwigs,” Dr. Roe said.
The team’s work is inspired by a paper published back in the 1950s that says that in the early stages of the earwig’s life, if their pincers are removed, they’ll grow back given time. Outside of this one source, it has never been recorded that the earwigs can actually regrow these or any other appendages. The goal is to repeat the outcome of the initial study from the 1950s, establishing that the earwigs truly can regrow the missing pincers. The next step would be to figure out which gene or genes are responsible for the regeneration. After that, the team would make earwigs a model system for continued study in the future.
The project was officially set into motion last summer when earwig specimens were collected from various local locations. They were housed separately to avoid any cross-breeding between the different sample populations. Collecting the earwigs was the easy part though. Now the hard part had just begun. Keeping the buggers alive and actively breeding was the next big step. This is where the project’s first major snag came up with getting the earwigs to eat.
“Some papers said that they (earwigs) would eat certain fruits or that they would eat bird seed, but they won’t eat ours,” Sabrina said. To date the team has found that the earwigs will eat only Romaine lettuce and nothing else that is given to them. This is in contrast to prior research. Once the team solved the food issue, the next was to get the earwigs to breed so that the experiments could start on the offspring. It took some time, but the first batch of eggs was laid on Dec. 1, 2017, and hatched almost two months later on Jan. 25, 2018.
“The mother earwig will actually clean her eggs and take care of her eggs. So there are some scientists that test or study earwigs because they do what is called maternal care, which is where the mothers take care of their babies,” Dr. Roe said. Though this is unrelated to the research the team is conducting, it is very interesting. It is uncommon for insects to show this type of behavior of maternal care toward their young. This is another reason the earwig has the potential to become a model system.
Now the baby earwigs are nearing the age where the experiments can start. Young earwigs will begin having one of their pincers cut off in order to test if earwigs really do have the ability to regrow organs. The team will run many tests and experiments on the young earwigs in the near future. If it’s found that they can regrow the lost organs, then the next step will be to identify what specific gene(s) is the cause of the regeneration. Then it too will be up for research.
Only time will tell if the hard work of Dr. Roe and her team will bear the fruits of success. All they can do is wait and see.
