A new study shows that the complex caste system of ants may be partly controlled by an insect version of the blood-brain barrier, a gatekeeper that allows only certain substances into the brain.
An anthill is a tightly organized community of insects, with clear division of roles to ensure smooth operation.While the queen bee lays eggs, the worker bees Ali Ants search for food and protect their nests as soldiers. Ant hormones, including something called “juvenile hormone,” determine what role each ant plays.
However, the underlying molecular controls that regulate these hormones and shape social behavior are not well understood.
Recent research has shown that the blood-brain barrier (BBB), a filter that protects the brain from unwanted and potentially harmful substances, plays a role in this process.The survey results were published in the magazine on September 7th. cellshow that the ant BBB regulates hormone levels that enter the brain, influencing the role of workers within the colony.
Related: These queen ants live 500% longer than the workers. Now I understand why.
In this study, the researchers set out to understand the basis of behavioral differences between foragers and soldier ants. They investigated which genes and proteins are differentially expressed between these two classes of worker ants, the Florida carpenter ants (Camponotus floridianus). They discovered that an enzyme that breaks down juvenile hormone, called juvenile hormone esterase, is present only in the cells that make up the ant’s BBB.
Their analysis revealed that soldier ants had higher levels of the juvenile hormone esterase than foraging ants, and therefore less of the hormone was taken up by the soldiers’ brains.
When researchers bypassed the BBB and injected juvenile hormone directly into the brains of soldier ants, the ants abandoned their role as mercenaries and began foraging. When the researchers manipulated the gene that produces the juvenile hormone esterase to reduce its supply, they saw similar changes in the ants’ social behavior. Lacking the enzymes to break it down, the juvenile hormone reached the ants’ brains and reprogrammed their behavior.
Previous research The study’s co-lead authors reported that the BBB may regulate hormone levels in the insect brain. Karl Glastadresearchers at the University of Pennsylvania told Live Science via email.
“But the fact that the ant’s blood-brain barrier dynamically regulates juvenile hormones between these two types of worker ants in a way that controls such important behavior does not seem to suggest to us that I was really surprised,” he said.
“It’s a really exciting discovery that the access of juvenile hormones to the brain is so tightly regulated at the level of the blood-brain barrier.” Daniel CronauerAn evolutionary biologist at Rockefeller University who was not involved in the study told Live Science in an email.
To see if this enzyme affects less socially complex insects, the researchers conducted experiments in fruit flies.Drosophila melanogaster). Switching on the juvenile hormone esterase gene in the fly BBB caused behavioral changes similar to those seen in ants. The genetically modified flies spent less time searching for food than unmodified flies.
More research is needed to understand the factors that control the amount of juvenile hormone esterase that reaches the ant’s BBB, Glastad said. However, these findings reveal an unknown role for the BBB in insects. It is not just a passive sieve, he said, but an active component of the entire behavioral circuit.
To find out whether other animals use similar mechanisms to control hormones entering the brain, the researchers analyzed published data from other labs. They found that several hormone-degrading enzymes were also present in cells of the mouse BBB. (A similar enzyme has not been found in the human BBB, but this structure controls hormones in other ways.)
“It would be very surprising to me if similar independently evolved mechanisms did not exist in other organisms,” Glastad said.
Professor Kronauer said he was cautious about extending the findings from insects to mammals, but suggested that mammals may have a similar system in the BBB that regulates hormone levels in the brain by breaking down molecules. I admitted that I have sex.
“But we’ll need more experimental work to figure that out,” he says.