Apr 18, 2012

Micro RNA Dictates Worker Bee Roles In The Colony

Johnny Mason, April 18, 2012:

You may or may not know that as a honey bee ages, its role in the colony changes. Generally, after a few days free of the brood comb, a newborn worker bee will go straight to work as a nurse bee, feeding the next generation of larvae and secreting beeswax to seal open cells, and also attend to the queen. I want to see your three day old do that!

After a week or so, the worker will move on to things such as ventilation of the nest, packing pollen in cells, grooming other members of the colony and other tasks as needed. It’s not until toward the end of her own life will a worker venture out to become a forager and start collecting nectar and pollen to bring back to the hive.

This is all fascinating stuff, but how/why do they do it? Yehuda Ben-Shahar, PhD, an assistant professor of biology at Washington University in St. Louis wondered that also. He pondered whether or not this behavior was under some sort of genetic control. In his research, it turns out that this division of labor is directly tied the presence of tiny snippets of noncoding RNA (micro RNAs or miRNAs) that suppress the expression of genes in the brains of honey bees.

For example, a forager bee has higher levels of these micro RNAs in their brains than a nurse bee that stays with the colony and tends to the brood. Ben Shahar says that Micro-RNAs are also known to regulate development and disease processes such as cancer.

“We wondered if they weren’t playing a role in regulating social behaviors,” he says, “because recent studies have implicated them in complex nervous-system functions such as neurodevelopment, psychiatric disease, and circadian clocks.”