In the animal kingdom, there are many examples of "marriage gifting" behavior in which a male courts a female and gives the female what he or she has eaten by mouth.The mechanism by which this behavior is produced has been unknown.

　This time, Professor Daisuke Yamamoto and Yoshiya Tanaka of the Graduate School of Life Sciences, Tohoku University, and others have obtained interesting findings that will lead to the elucidation of the circuit that produces the donation behavior for a type of Drosophila that presents marriage.

　Sexual behavior such as Drosophila courtship behavior is determined by a gene called the fru gene.Drosophila, D. subobscura (no Japanese name), is the only species in the same genus in which males donate marriages to females are essential for successful mating.This time, the research group edited the genome of D. subobscura and incorporated the gene of the protein that causes excitement of brain cells when exposed to light inside the fru gene that controls sexual behavior.Then, the circuit was artificially activated by the irradiation of light, and what kind of action was caused was investigated.As a result, when exposed to light, D. subobscura's unique marriage-giving behavior was repeatedly induced in the absence of females.

　From this, it is inferred that in the brain of D. subobscura, the cells in which the fru gene works are partially different from those of other Drosophila, and their unique cells produce the behavior of D. subobscura's unique marriage donation.

Paper information:[Journal of Neuroscience] Optogenetic activation of the fruitless-labeled circuitry in Drosophila subobscura males induces mating motor acts