Florida carpenter ant colonies possess distinct worker castes, and each shows vast differences in their social behavior throughout the course of their lives. However, a new study by University of Pennsylvania researchers found that these caste-specific behaviors are not irreversible - they can be reprogrammed by epigenetic factors, suggesting that genetic makeup may not be as important as epigenetics in determining ant colony behavior.
The team found that case-specific foraging behaviors can be changed by altering the balance of epigenetic chemicals called acetyl groups, which are attached to the histone protein complexes that DNA strands are wrapped around in cell nucleus'. In particular, the researchers inhibited either the addition or removal of these acetyl groups on histones and observed a change in the expression of nearby genes.
"The results suggest that behavioral malleability in ants, and likely other animals, may be regulated in an epigenetic manner via histone modification," Daniel Simola, lead author of the study, said in a press release.
One gene that was of particular importance in the study was CBP, which is an epigenetic "writer" enzyme that works by changing chromatin through the addition of acetyl groups to histones. The scientists believe that differences in CBP activity among different castes may guide gene expressions and alter behavior.
"From mammalian studies, it's clear this is an important protein involved in learning and memory," said Shelley Berger, senior author of the study. "The finding that CBP plays a key role in establishing distinct social behaviors in ants strongly suggests that the discoveries made in ants may have broad implications for understanding social organization."
The findings were published in the Dec. 31 issue of Science.
