It\u2019s the culmination of nearly a decade\u2019s work by several members of the Japanese team, including co-first author Ryoya Tanaka, who in 2017 led a study mapping and comparing the mating circuits of the two fly species \u2013 D. melanogaster, which courts by singing, and D. subobscura, which regurgitates food as a romantic gesture (“gift-giving”). By using optogenetics to trigger gift-giving in D. subobscura, they confirmed that a gene called Fruitless (Fru) \u2013 present in both species \u2013 played a key role in courtship, but controled very different behaviors in each.<\/p>\n
<\/p>\n
Drosophila subobscura males regurgitate food and offer it as a gift to females during courtship<\/p>\n
Tanaka et al., 2025<\/p>\n
Now, the Japanese researchers have taken this to a completely new level, using genetic manipulation to turn D. melanogaster males \u2013 who diverged from the other species around 35 million years ago \u2013 into gift givers, not singers. While we can’t say for sure, when the increasingly distinct species continued down their own path of evolution from a common ancestor, environmental pressures and mating preferences would have shaped their “love language.” One refined its wing muscles and song circuits to produce the sonic courtship ritual, the other boosting the visual and motor circuits for regurgitating and presenting food to a female.<\/p>\n
Essentially, turning D. melanogaster<\/a> flies into gift-givers is not something that can be “unlocked” \u2013 it vanished possibly tens of millions of years ago. <\/p>\n Scientists have now upended this evolutionary journey, genetically rewiring the brains of D. melanogaster by “switching” on the Fru gene in the singing flies’ insulin-producing neurons \u2013 where you’ll find the gene lurking in the heads of the gift-givers \u2013 to manipulate it to form totally new neural connections, resulting in the behavior transferral to the other species.<\/p>\n It represents the first example of manipulating a single gene to transfer this foreign behavior to another species. <\/p>\n The gene flip enabled new neuronal pathways to form, resulting in courtship behavior previously unknown to the species<\/p>\n The scientists inserted DNA into D. subobscura embryos so that certain brain cells would produce heat-activated proteins. By briefly warming the flies, they could switch these targeted neurons on. This revealed a cluster of 16\u201318 insulin-producing neurons in the pars intercerebralis \u2013 the insect brain\u2019s neurosecretory center \u2013 that make the male-specific protein FruM. Comparing this region to D. melanogaster showed that, in the gift-giving species, the insulin neurons are wired into the courtship circuit \u2013 while in the singing species, they’re not. <\/p>\n In D. melanogaster, the insulin-producing neurons aren\u2019t connected to the Fru-driven courtship circuit, which means regurgitation simply isn\u2019t part of their skillset \u2013 their wiring and genetic programming make it impossible. However, the researchers figured out how to switch on the fru gene in these neurons, effectively rewiring the circuit so the singing flies could perform the foreign gift-giving behavior.<\/p>\n Remarkably, this behavioral switch occurred with no learning or social exposure \u2013 it came about purely through reconfigured neural circuitry.<\/p>\n \u201cWhen we activated the fru gene in insulin-producing neurons of singing flies to produce FruM proteins, the cells grew long neural projections and connected to the courtship center in the brain, creating new brain circuits that produce gift-giving behavior in D. melanogaster for the first time,\u201d said Ryoya Tanaka, co-lead author and lecturer at Nagoya University\u2019s Graduate School of Science.<\/p>\n The genetically engineered courtship transfer highlights how some animals may carry hidden, evolutionarily dormant behaviors in their neural architecture. So activating the right genetic switch can awaken these ancient programs \u2013 even if they\u2019re completely foreign to the species in question.<\/p>\n \u201cOur findings indicate that the evolution of novel behaviors does not necessarily require the emergence of new neurons; instead, small-scale genetic rewiring in a few preexisting neurons can lead to behavioral diversification and, ultimately, contribute to species differentiation,\u201d said co-lead author Yusuke Hara, from the National Institute of Information and Communications Technology (NICT).<\/p>\n Last year, scientists mapped the 50 largest neurons of the fruit fly brain connectome<\/p>\n Tyler Sloan and Amy Sterling for FlyWire, Princeton University, (Dorkenwald et al., 2024)<\/p>\n But this is more than a mad-science experiment \u2013 fruit fly species, although distinct from each other, share around 60% of their genetic makeup with humans. And scientists believe three in four human genetic diseases have a parallel condition in fruit flies. It’s no surprise that research on fruit flies \u2013 the model species D. melanogaster, in particular \u2013 has earned scientists six Nobel prizes to date. In 2024, researchers created the most detailed neuronal map of the fly’s brain<\/a>. <\/p>\n This latest study offers real proof that small genetic tweaks \u2013 in this case, a single gene \u2013 in circuitry can redesign behavior at a species level. While no-one is suggesting we\u2019ll be engineering new instincts in humans anytime soon, the work shows it\u2019s possible to activate entirely novel behaviors by tweaking the brain\u2019s wiring at the genetic level. It hints that some behaviors may lie dormant in our own biology \u2013 hard-wired but silent \u2013 waiting for the right molecular \u201cswitch\u201d to turn them on.<\/p>\n “We\u2019ve shown how we can trace complex behaviors like nuptial gift-giving back to their genetic roots to understand how evolution creates entirely new strategies that help species survive and reproduce,” said senior author Daisuke Yamamoto from NICT.<\/p>\n The study was published in the journal Science<\/a>.<\/p>\n Source: Nagoya University<\/a> via EurekAlert!<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"In a breakthrough study, scientists have transferred a courtship behavior from one species to another, triggering the recipient…\n","protected":false},"author":2,"featured_media":23675,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[272],"tags":[20006,19995,19996,18,6721,20002,19994,20000,19993,19997,20003,458,19,20005,17,19998,20001,20004,19999,133],"class_list":{"0":"post-23674","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-genetics","8":"tag-behavioral-diversification-in-flies","9":"tag-drosophila-melanogaster","10":"tag-drosophila-subobscura","11":"tag-eire","12":"tag-evolutionary-biology","13":"tag-evolutionary-dormant-behaviors","14":"tag-fruit-fly-courtship-behavior","15":"tag-fruitless-gene-in-flies","16":"tag-genetic-behavior-transfer","17":"tag-genetic-manipulation-in-flies","18":"tag-genetic-rewiring-in-species","19":"tag-genetics","20":"tag-ie","21":"tag-insulin-producing-neurons","22":"tag-ireland","23":"tag-neural-circuitry-in-insects","24":"tag-neural-connections-and-behavior","25":"tag-novel-behaviors-in-evolution","26":"tag-optogenetics-in-research","27":"tag-science"},"share_on_mastodon":{"url":"","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/23674","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/comments?post=23674"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/23674\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media\/23675"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media?parent=23674"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/categories?post=23674"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/tags?post=23674"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}<\/p>\n
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