Social isolation leads to changes in the behavior and activity of immune and stress genes
Ants interact with social isolation in the same way that humans and other social mammals do. A study by an Israeli-German research team revealed changes in the social and health behavior of isolated ants from their group. The research team was particularly surprised by the fact that immune and stress genes are less regulated in the brains of isolated ants. “This makes the immune system less efficient, and it is also a visible phenomenon in the social isolation of humans – particularly at the present time during the COVID-19 crisis,” said Professor Susan Voitsick, who led the study at the Johannes Gutenberg University Mainz (JGU). The study of an ant that is native to Germany was recently published Molecular Ecology.
The effects of isolation in social insects have been little studied so far
Humans and other social mammals experience isolation from their group as a stressor, and it has a negative impact on their overall well-being and physical health. Professor Einon Scharf, lead author of the article and collaborative partner of the Mainz Research Group in Tel Aviv, added: “Lonely people become lonely, depressed and anxious, become addicted more easily, have weak immune systems and poor overall health.” University in Israel. While the effects of isolation have been studied extensively in social mammals such as humans and rats, little is known about how social insects respond in similar situations – even though they live in highly developed social systems. Ants, for example, live their entire lives as members of the same colony and depend on their mates in the colony. Working ants give up their reproductive potential and dedicate themselves to feeding the larvae, cleaning and defending the nest, and foraging for food, while the queen does more than just lay eggs.
The research team looked at the consequences of social isolation in the case of Temnothorax nylanderi ants. These ants inhabit hollows in acorns and sticks on the ground in European forests, and form colonies of a few dozen workers. Young workers involved in brood care were taken singly from 14 cells and isolated for varying periods of time, from 1 hour to a maximum of 28 days. The study was conducted between January and March 2019 and highlights three specific aspects in which changes have been observed. After their isolation ended, the workers were less concerned with their adult mates in the colony, but the length of time they spent on brood contact increased; They also spent less time taking care of themselves. “This decrease in healthy behavior may make ants more susceptible to parasites, but it is also a typical feature of social deprivation in other social creatures,” said Professor Susan Fotsik.
The stress of isolation negatively affects the immune system
While the study revealed significant changes in the behavior of isolated insects, their findings regarding genetic activity were more striking: the regulation of several genes related to immune system function and response to stress was reduced. In other words, these genes were less active. Professor Enun Scharf said: “This finding is consistent with studies in other social animals that showed weakened immune systems after isolation.”
The discovery by a team of biologists led by Professor Susan Voitzyk is the first of its kind, combining behavioral and genetic analyzes of the effects of isolation on social insects. “Our study shows that ants are affected by isolation like social mammals, and indicates a general link between social well-being, stress tolerance, and immune competence in social animals,” Wojtsick concluded, summarizing the results of the Israeli-German study. Foitzik is also collaborating with her Israeli partner Professor Inon Scharf and with co-author and group leader Dr Romain Libbrecht of JGU on a new joint project on the benefits of physical fitness and the molecular basis of spatial learning in ants, funded by the German Research Foundation (DFG).