Bees tend to be social and cooperative insects, working together for the good of the entire hive. You don’t expect entire colonies to suddenly begin fighting amongst each other and for usurpers to try and take over as queen bee. However, one species, the South African Cape bee, has one specific gene that can turn these usually social, organized insects into fighting parasites. For the first time, an international team of researchers headed by Martin Luther University Halle-Wittenberg (MLU) have been able to isolate and explain the very rare genetic basis that causes this phenomenon, their findings recently published in the journal Molecular Biology and Evolution.
Bees are one of the social insect species that are able to live together in large colonies that have a clear social structure. The roles within a bee colony are usually clearly and equally distributed. You have the queen bee that is responsible for reproducing to provide all of the offspring in the colony. The male drones work to provide food for the colony and do most of the physical work. There are also many infertile female worker bees that care for the nest and the queen, basically her handmaidens. The male drones are born from the queen’s unfertilized eggs, while the female workers come from the fertilized ones. Generally, the queen is the queen until she dies, is too old to keep producing offspring, or the colony divides.
However, this is not the case with the South African Cape bee. They have a gene that allows some of the female worker bees produce female offspring from unfertilized eggs. These bees are often referred to as false queens. After these false queens are grown, they begin to make more of their own kind, which they will then use to invade foreign bee colonies that are still closely related to them and usurp their queen’s throne, taking over the hive. This phenomenon in which these female worker bees are born with fully develop ovaries, which allow them to produce their own little bees from their unfertilized eggs is known as parthenogenesis. This occasionally happens with other bee species too. But the Cape bees are able to produce females, and not just drones like with parthenogenesis, from their unfertilized eggs, a phenomenon known as thelytoky.
Scientists have spent years trying to discover why the South African Cape bees can do this while other species cannot and looking specifically for some genetic basis for the phenomenon. They were finally able to crack this case and found a special gene responsible for these parasitic offspring. Just a small variation in the code of this particular gene sets the phenomenon thelytoky in motion. They were also able to demonstrate that this gene is a dominant genetic trait, which should mean that the phenomenon should spread to more and more bee colonies. But this doesn’t happen for some reason, meaning that underlying mechanism that puts this gene into motion is much more complex, and still needs to be further studied.
Why do you think this strange phenomenon doesn’t spread and seems to affect only South African Cape bees?