Welcome to the next episode of The Worm Podcast 🧠Today we are talking about a problem every animal faces:where should I spend my energy?For C. elegans, the answer depends partly on sex.Hermaphrodites need to balance food, reproduction and survival. Males have an extra problem: they also need to find a mate.This new study identifies SKN-1B, a neuronal version of the conserved Nrf transcription factor, as part of the switch that helps control those competing priorities.🍽️ Food or mate?SKN-1B is expressed in sensory neurons involved in food sensing and metabolism.In hermaphrodites, SKN-1B promotes food-seeking behaviour.But males behave differently.Male skn-1b mutants left food faster when no mate was present, suggesting increased mate-searching behaviour.Give them a hermaphrodite, or even just hermaphrodite pheromones, and they stayed.So the worms were not simply more active.They were changing what they prioritised.🧬 The effect lasts into older ageThe difference became even more interesting as the worms aged.Wild-type male exploration declined with age.But skn-1b mutant males maintained exploratory behaviour and were more likely to retain mating ability at day 5 of adulthood.The authors therefore suggest that SKN-1B normally acts to suppress male mate-searching behaviour, including later in life.🧠 A sex-specific molecular switchThe transcriptomic effects were striking.Loss of skn-1b changed only hundreds of genes in hermaphrodites, but thousands in males.The paper also found sex-specific effects on mitochondrial organisation and function.So the same neuronal transcription factor can produce very different whole-animal outcomes depending on whether the worm is male or hermaphrodite.🔬 The signalling pathwayThe authors traced part of the behavioural effect through a neuroendocrine pathway involving:• DAF-7 TGF-β signalling• insulin signalling• ODR-10, an olfactory receptor involved in food sensingIn skn-1b mutant males, DAF-7 increased while odr-10 expression fell.Reducing ODR-10 in wild-type males also increased exploration and food-leaving behaviour.That links SKN-1B directly to the neural machinery balancing feeding and mating.🧠 The take-home messageThis is not simply a story about male worms being more interested in mating than food.It is about how the nervous system decides where energy should go.SKN-1B acts as a sex-specific behavioural and metabolic switch, helping balance:food × energy × reproduction × ageingAnd in males, removing that switch seems to keep mate-searching behaviour going for longer.📄 Paper discussedNoviann McLean, Minaxi S. Gami, Nathan Dennis, Yasir Malik, Justin De Araujo, James Evans, Lydia Bennett, Marina Ezcurra and Jennifer M. A. Tullet (2026)Neuronal Nrf/SKN-1B controls a sexually dimorphic neuroendocrine pathway for C. elegans exploratory behaviourPLOS Genetics, 22(8): e1012239DOI: https://doi.org/10.1371/journal.pgen.1012239If you enjoyed this episode, please like, follow and subscribe to The Worm Podcast ⭐This podcast is generated with artificial intelligence and curated by Veeren. If you would like your publication or product featured on the show, please get in touch.🔗 www.veerenchauhan.com📧 [email protected]

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