Researchers have developed a fascinating courtship behavior in fruit flies through genetic modification. A Japanese team changed one gene in the common fruit fly, Drosophila melanogaster, allowing it to mimic the courtship behavior of another species, Drosophila subobscura.
In typical fly dating, male D. melanogaster perform complex wing vibrations to create a “song” that attracts females. On the other hand, D. subobscura has a unique love language: males offer regurgitated food to woo potential mates.
Both species are closely related, diverging around 30-35 million years ago. Over time, their brain functions evolved differently. In D. subobscura, the center of courtship is linked to insulin-producing neurons, while in D. melanogaster, these two brain regions remain separate.
To investigate these differences, researchers modified the flies’ DNA to control gene activity with heat. When they activated the insulin neurons in D. melanogaster, the flies exhibited gift-giving behavior for the first time. Ryoya Tanaka, a neurobiologist from Nagoya University and co-author of the study, noted that this modification created new brain circuits related to courtship.
Interestingly, both fly species share a key gene called “FruitlessM” or “FruM” that influences male courtship behavior. In D. subobscura, the insulin neurons also produce this courtship protein, but this isn’t the case for D. melanogaster. Turning off the genes responsible for the behavior in D. subobscura eliminated their regurgitation gift.
Yusuke Hara, another researcher involved in the study, emphasized that evolving new behaviors doesn’t always require new neurons. Instead, small changes within existing ones can lead to significant behavioral changes and even species differences.
This study sheds light on the complex connections between genetics and behavior in evolution. It shows how minor tweaks in DNA can lead to remarkable changes in behavior, offering insights into the nature of courtship not just in fruit flies, but potentially in other species as well.
The findings were published in the journal Science. For more detailed information, you can access the original article here.
