A Harpegnathos saltator employee recorded in an aggressive display screen (open mandibles) focused on the professional photographer. Credit: Karl Glastad (Berger Lab)
Depending on the result of social disputes, ants of the types Harpegnathos saltator do something uncommon: they can change from an employee to a queen-like status referred to as gamergate. Now, scientists reporting in the journal Cell today (November fourth, 2021) have actually made the unexpected discovery that a single protein, called Kr- h1 (Kru ̈ppel homolog 1), reacts to socially managed hormonal agents to manage this complex social shift.
“Animal brains are plastic; that is, they can change their structure and function in response to the environment,” states Roberto Bonasio of the University of Pennsylvania Perelman School ofMedicine “This process, which also takes place in human brains—think about the changes in behavior during adolescence—is crucial to survival, but the molecular mechanisms that control it are not fully understood. We determined that, in ants, Kr-h1 curbs brains’ plasticity by preventing inappropriate gene activation.”
Illustration revealing ant with eggs. Credit: Illustration by Tim Christopher based upon photography by Brigitte Baella and Karl Glastad
In an ant nest, employees preserve the nest by discovering food and battling intruders, whereas the queen’s primary job is to lay eggs. And, yet, it is the exact same hereditary guidelines that generate these extremely various social functions and habits. By studying ants, Bonasio and coworkers, consisting of Shelley Berger, likewise at the University of Pennsylvania, wished to comprehend how turning particular genes “on” or “off” impacts brain function and habits. Because Harpegnathos grownups can change from an employee to a gamergate, they were ideal for such research studies.
So that they might study the underlying molecular occasions that trigger such a switch, the research study group, led by co-first authors Janko Gospocic and Karl Glastad, established a technique for separating nerve cells from the ants and keeping them alive in plastic meals in the laboratory. This enabled the group to check out how the cells reacted to modifications in their environment, consisting of hormonal agent levels.
Illustration demonstrating how transcriptional repressor Kr- h1 supports caste identity by reducing improper social habits. Credit: Illustration by Roberto Bonasio based upon photography by Brigitte Baella and Karl Glastad
These research studies even more determine that 2 hormonal agents, juvenile hormonal agent, and ecdysone, which exist at various levels in the bodies of employees and gamergates, produced unique patterns of gene activation in the brains of the 2 castes. The most significant surprise was that both hormonal agents affected the cells by triggering a single protein, Kr- h1.
“This protein regulates different genes in workers and gamergates and prevents the ants from performing ‘socially inappropriate’ behaviors,” Berger states. “That is to say, Kr-h1 is required to maintain the boundaries between social castes and to ensure that workers continue to work while gamergates continue to act like queens.”
“We had not anticipated that the same protein could silence different genes in the brains of different castes and, as a consequence, suppress worker behavior in gamergates and gamergate behavior in workers,” Bonasio includes. “We thought that these jobs would be assigned to two or more different factors, each of them only present in one or the other brain.”
The findings expose essential functions for socially managed hormonal agents and gene policy in the capability of animal brains to change from one hereditary mode and social caste to another. “The key message is that, at least in ants, multiple behavioral patterns are simultaneously specified in the genome and that gene regulation can have a great impact on which behavior that organism carries out,” Berger states. “In other words, the parts of both Dr. Jekyll and Mr. Hyde are already written into the genome; everyone can play either role, depending on which gene switches are turned on or off.”
The scientists believe the ramifications might go much further than comprehending behavioral plasticity in ants and other pests. “It is tempting to speculate that related proteins might have comparable functions in more complex brains, including our own,” statesBonasio “Discovering these proteins might allow us to one day restore plasticity to brains that have lost it, for example aging brains.”
The discovery that a single aspect can reduce various sets of genes and habits in various brains raises essential concerns about how the double function of this protein and others like it may be managed. In future research studies, the scientists prepare to check out the function of Kr- h1 in other organisms. They state they likewise wish to check out how the environment affects gene policy at the epigenetic level– through the existence or lack of particular chemical marks on DNA— and how this in turn effects brain plasticity and habits.
Reference: “Kr-h1 maintains distinct caste-specific neurotranscriptomes in response to socially regulated hormones” 4 November 2021, Cell
DOI: 10.1016/ j.cell.202110006
This work was supported by the National Institutes of Health, the Searle Scholars Program, and the 2020 Max Planck-Humboldt Research Award.
