Indian Jumping Ants Can Shrink and Regrow Their Brains
- Changes in observable characteristics allow organisms to respond to changing environments.
- However, these changes are usually not reversible.
- A long-lived vertebrate species was observed to exhibit seasonal changes in brain size.
- Similar changes have not been observed in short-lived species like insects.
- Researchers revealed a change in brain size of reproductive worker ants Harpegnathos saltator also known as Indian jumping ants.
- H. saltator worker ants are capable of sexual reproduction, unlike most ant species.
- They compete in a dominance tournament to establish a group of reproductive worker ants called “gamergates”.
- In comparison with the foragers who usually search for food, gamergates show a 19% reduction in brain volume.
- They also differ in behavior, ovarian status, cuticular hydrocarbon profile, venom production, and expression profiles of related genes.
- Researchers manipulated gamergates to observe the traits.
- After 6-8 weeks from being reverted back to non-reproductive status, their observable traits changed to the forager type across all traits they measured.
- The changes in traits include brain volume which changes were shown to be irreversible in Drosophila and honeybees.
- The change in brain size of H. saltator is more similar to that found in some long-lived vertebrates that display reversible changes in brain volume.
Penick Clint A., Ghaninia Majid, Haight Kevin L., Opachaloemphan Comzit, Yan Hua, Reinberg Danny and Liebig Jürgen 2021Reversible plasticity in brain size, behavior and physiology characterizes caste transitions in a socially flexible ant (Harpegnathos saltator)Proc. R. Soc. B.2882021014120210141. http://doi.org/10.1098/rspb.2021.0141