Science

Scientists map male fruit fly brain connections to reveal genetic wiring differences

A comparison with female fly neural maps shows that a 5% difference in brain cells drives distinct courtship and aggressive behaviors.

Updated Sep 3, 2026 · 16:18 UTC1 reports

The short version

Researchers mapped all 124 million neural connections in a male fruit fly's brain and compared them with a previously mapped female brain.
While 95% of brain cells are identical between sexes, the remaining 5% create distinct circuits for aggression, visual tracking, and courtship songs.
Scientists say the comparative wiring model could help explain how genetic variants influence complex behaviors and human neurodevelopmental conditions.

Researchers mapped all 124 million nerve cell connections in a male fruit fly's brain, completing a 3D diagram to compare against a female fly brain map produced two years prior.[BBC News]
The study, published in the journal Cell, was conducted by researchers from the Medical Research Council's Laboratory of Molecular Biology, the University of Cambridge, HHMI Janelia Research Campus, Google Research, and the Champalimaud Foundation.[BBC News]
Male and female fruit fly brains share roughly 95% of their cells, while the remaining 5% contain wiring differences linked to male-specific aggression, visual tracking during courtship, and wing-vibration songs.[BBC News]
The observed anatomical wiring differences between the sexes are driven by two known genes.[BBC News]

Researchers emphasize that the insect findings cannot explain behavioral differences between human men and women due to human complexity.[BBC News]
The extent to which these fly connectome insights will successfully translate to understanding human conditions like autism and schizophrenia or improving artificial intelligence architectures remains to be demonstrated.[BBC News]