Do bees also "autistic" and "social"? Warmer and cooler environments also affect spawning

Sweat bees help researchers understand the genetic basis of social behavior. Image credit: BRIAN VALENTINE

An enduring mystery in biology is how some animals— from humans to bees — have become social. Now, a study suggests that in humble sweat bees, a change in the expression of a single gene may determine which sweat bees are solitary and which are good at socializing. This gene, which was previously associated with human autism, is also associated with the social behavior of animals such as mice and locusts. The latest findings take scientists one step closer to demonstrating the co-evolutionary cornerstone of social behavior.

In the 1950s, French biologist Cécile Plateaux-Quénu documented two different behaviors of a sweat bee, the tunnel bee. Female tunnel bees that live in the colder parts of France usually do not have "helpers", while female tunnel bees in warmer regions do have "helpers". Meanwhile, in warmer regions, female tunnel bees lay two sets of eggs — the first group of hatched tunnel bees tends to the second. Plateaux-Quénu's research also confirms that this difference is inherited.

Twenty years later, Sarah Kocher, an evolutionary geneticist now working at Princeton University, decided to follow down Theraux-Quénu's seminal research. She collected 150 bees from 3 cold and 3 warm regions of France. Kocher and colleagues, who were postdocs at Harvard at the time, analyzed the bees' DNA to look for genetic differences that might explain the two behaviors.

After sequencing and comparing the genomes of 6 groups of tunnel wasps, the researchers found 200 differences centered on 62 genes. Among them, a gene called syntaxin 1a caught people's attention. It is responsible for creating synaptic fusion proteins, a protein that plays an important role in transmitting signals between nerve cells. According to Kocher, this gene, which is linked to the social behavior of many animals, best distinguishes social and solitary sweat bees.

Subsequently, Kocher measured the gene's activity in social and solitary sweat wasps. The gene is about 15 times more active in social sweat wasps than in solitary sweat wasps. The researchers reported this result in the recent publication of the journal Nature Communications. (Xu Xu)

Related thesis information: DOI:10.1126/science.aav7683

China Science Daily (2018-10-24 2nd Edition International)