First-Ever Interspecies ‘Behavior Transplant’ Performed

Metaverse Planet August 18, 2025Last Updated: August 18, 2025

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Japanese scientists have achieved the first-ever behavior transfer between fruit fly species by manipulating a single gene. The transfer focused on mating behavior.

In a groundbreaking achievement for the scientific world, Japanese researchers have successfully transferred the mating behavior of one species to another through genetic intervention. A team from Nagoya University and NICT permanently instilled a completely foreign behavior between fruit fly species by manipulating just one gene.

The Experiment Used Flies

The research was conducted on two different fruit fly species: Drosophila melanogaster (which courts by singing) and Drosophila subobscura (which offers food to the female). These two species evolutionarily diverged about 35 million years ago and developed completely different mating strategies. However, scientists were able to transform the singing species into a “gift-giving” one by connecting a gene called “Fruitless” (Fru), found in both species, to different neural circuits.

The team first discovered that in D. subobscura, 16-18 insulin-producing neurons in the brain were connected to the mating circuit under the control of the Fru gene. Since this connection does not exist in D. melanogaster, the food-offering behavior never occurs. Using genetic engineering, the researchers activated the Fru gene in these specific neurons in the singing flies. As a result, new neural connections formed in the flies’ brains, and the gift-giving behavior emerged purely through genetic modification, without any learning process.

The research suggests that behaviors that have been evolutionarily erased or never existed may lie “dormant” within the brain’s existing structure. Co-author Yusuke Hara commented on the subject, stating, “Our findings indicate that the emergence of new neurons is not necessary for the evolution of new behaviors. Instead, small-scale genetic rewiring in a few pre-existing neurons can lead to behavioral diversity and ultimately contribute to the differentiation of species.”

Fruit flies share approximately 60% of their genetic makeup with humans, and conditions corresponding to 75% of human genetic diseases can be observed in these organisms. Therefore, this research not only helps in understanding insect behavior but may also provide clues about hidden behavioral programs in the human brain.