Nav: Home

Epigenetic switch found that turns warrior ants into forager ants

November 12, 2019

In 2016, researchers observed that they could reprogram the behavior of the Florida carpenter ant Camponotus floridanus. This species has two distinct castes with nearly identical genetic makeup: smaller Minor workers who forage and nurse the ant brood and larger Major worker soldiers that defend the colony. On November 12 in the journal Molecular Cell, the same group reports that ant castes are determined by epigenetic influences. Specifically, they discover that the neural repressor, known as CoRest, is a major contributor to influencing forager or worker behaviors.

"We view this as an epigenetic mechanism," says senior author Shelley Berger, whose laboratory at the University of Pennsylvania studies genome regulation and the influence of epigenetics in cancer, aging, and neurodegenerative disease. "The genomes are nearly identical, much like how the genome is the same in our tissues and organs. There are epigenetic changes that lead to cell differentiation, so we want to know what the epigenetic mechanisms are that are driving this dramatic difference at the organismal level in these ants."

In the 2016 experiments, by injecting the ants with the histone deacetylase (HDAC) inhibitor trichostatin A (TSA), Berger and her colleagues could reprogram the Major worker ants to act more like foraging Minors. To dive deeper into the precise epigenetic mechanism involved with these ants, the researchers injected TSA at specific times in early adulthood and performed more specific tests designed to measure markers of epigenetic activity, such as chromatin marks, as well as their gene expression.

Early on, they identified the neural repressor known as CoRest. When the Majors were reprogrammed with TSA, they noticed that Major ants started acting like Minor foragers, and many genes were turned on in the reprogrammed Majors that are usually on only in Minors. "We also saw that CoRest is upregulated in these Major ants," says first author Karl Glastad (@Laevorotatory), a postdoctoral researcher the University of Pennsylvania.

Gene expression testing during the reprogramming phase showed that CoRest repressed enzymes that degrade juvenile hormone (JH). JH is naturally elevated in Minors. When they compared the natural Minors with the reprogrammed Majors, they saw mirrored patterns: high CoRest, high JH levels, and low JH degradation. "This is pretty strong evidence that chromatin regulation through CoRest is playing a major role in differentiating social behavior in these ants," says Glastad.

The team found that reprogramming could only be accomplished in a short window. In this paper, they could reprogram the Major soldier to forage up to a maximum of five days after hatching. At 10 days, reprogramming is impossible. "This means there is transient epigenetic plasticity that is linked to a long-lasting behavioral change," says Berger. "And it shows that an epigenetic mechanism can influence complex social behavior."

"The importance of timing, hormones, and how epigenetics regulates hormones all coalesce in this study," adds Glastad. "What we've shown here in one case with ants is how this is epigenetically regulated at a very punctuated time, and we think there are parallels in other species."

CoRest is found widely throughout animal species, all the way up through mammals, including humans. It is known to repress unwanted neural genes, but this is some of the first evidence that it has a role in directing behaviors. "We believe the activity of CoRest is highly conserved in Hymenoptera (ants, bees, wasps)," adds Berger. "They all have this complex sociality that is so fascinating, and we are using it because we think of it as a simple model to try and understand how complex sociality can be regulated."

Moving ahead, the team will study single cells in the brain looking at epigenetic changes at the cellular level. "We are trying to understand which cell types in the brain are being individually regulated," says Berger, "since we have some interesting early data that this change in CoRest regulation is occurring in a very specific cell type in the brain."
-end-
This work was supported by the National Institutes of Health and the National Institute on Aging.

Molecular Cell, Glastad et al. "Epigenetic regulator CoRest controls social behavior in ants." https://www.cell.com/molecular-cell/fulltext/S1097-2765(19)30790-7

Molecular Cell (@MolecularCell), published by Cell Press, is a bimonthly journal that focuses on analyses at the molecular level, with an emphasis on new mechanistic insights. The scope of the journal encompasses all of "traditional" molecular biology as well as studies of the molecular interactions and mechanisms that underlie basic cellular processes. Visit: http://www.cell.com/molecular-cell. To receive Cell Press media alerts, please contact press@cell.com.

Cell Press

Related Brain Articles:

Human brain size gene triggers bigger brain in monkeys
Dresden and Japanese researchers show that a human-specific gene causes a larger neocortex in the common marmoset, a non-human primate.
Unique insight into development of the human brain: Model of the early embryonic brain
Stem cell researchers from the University of Copenhagen have designed a model of an early embryonic brain.
An optical brain-to-brain interface supports information exchange for locomotion control
Chinese researchers established an optical BtBI that supports rapid information transmission for precise locomotion control, thus providing a proof-of-principle demonstration of fast BtBI for real-time behavioral control.
Transplanting human nerve cells into a mouse brain reveals how they wire into brain circuits
A team of researchers led by Pierre Vanderhaeghen and Vincent Bonin (VIB-KU Leuven, Université libre de Bruxelles and NERF) showed how human nerve cells can develop at their own pace, and form highly precise connections with the surrounding mouse brain cells.
Brain scans reveal how the human brain compensates when one hemisphere is removed
Researchers studying six adults who had one of their brain hemispheres removed during childhood to reduce epileptic seizures found that the remaining half of the brain formed unusually strong connections between different functional brain networks, which potentially help the body to function as if the brain were intact.
Alcohol byproduct contributes to brain chemistry changes in specific brain regions
Study of mouse models provides clear implications for new targets to treat alcohol use disorder and fetal alcohol syndrome.
Scientists predict the areas of the brain to stimulate transitions between different brain states
Using a computer model of the brain, Gustavo Deco, director of the Center for Brain and Cognition, and Josephine Cruzat, a member of his team, together with a group of international collaborators, have developed an innovative method published in Proceedings of the National Academy of Sciences on Sept.
BRAIN Initiative tool may transform how scientists study brain structure and function
Researchers have developed a high-tech support system that can keep a large mammalian brain from rapidly decomposing in the hours after death, enabling study of certain molecular and cellular functions.
Wiring diagram of the brain provides a clearer picture of brain scan data
In a study published today in the journal BRAIN, neuroscientists led by Michael D.
Blue Brain Project releases first-ever digital 3D brain cell atlas
The Blue Brain Cell Atlas is like ''going from hand-drawn maps to Google Earth'' -- providing previously unavailable information on major cell types, numbers and positions in all 737 brain regions.
More Brain News and Brain Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Debbie Millman: Designing Our Lives
From prehistoric cave art to today's social media feeds, to design is to be human. This hour, designer Debbie Millman guides us through a world made and remade–and helps us design our own paths.
Now Playing: Science for the People

#574 State of the Heart
This week we focus on heart disease, heart failure, what blood pressure is and why it's bad when it's high. Host Rachelle Saunders talks with physician, clinical researcher, and writer Haider Warraich about his book "State of the Heart: Exploring the History, Science, and Future of Cardiac Disease" and the ails of our hearts.
Now Playing: Radiolab

Insomnia Line
Coronasomnia is a not-so-surprising side-effect of the global pandemic. More and more of us are having trouble falling asleep. We wanted to find a way to get inside that nighttime world, to see why people are awake and what they are thinking about. So what'd Radiolab decide to do?  Open up the phone lines and talk to you. We created an insomnia hotline and on this week's experimental episode, we stayed up all night, taking hundreds of calls, spilling secrets, and at long last, watching the sunrise peek through.   This episode was produced by Lulu Miller with Rachael Cusick, Tracie Hunte, Tobin Low, Sarah Qari, Molly Webster, Pat Walters, Shima Oliaee, and Jonny Moens. Want more Radiolab in your life? Sign up for our newsletter! We share our latest favorites: articles, tv shows, funny Youtube videos, chocolate chip cookie recipes, and more. Support Radiolab by becoming a member today at Radiolab.org/donate.