title: Sex, age, and hunger regulate behavioral prioritization through dynamic modulation of chemoreceptor expression.
abstract: BACKGROUND
  Adaptive behavioral prioritization requires flexible outputs from fixed neural circuits. In C. elegans, the prioritization of feeding versus mate searching depends on biological sex (males will abandon food to search for mates, whereas hermaphrodites will not) as well as developmental stage and feeding status. Previously, we found that males are less attracted than hermaphrodites to the food-associated odorant diacetyl, suggesting that sensory modulation may contribute to behavioral prioritization.
  
  
  RESULTS
  We show that somatic sex acts cell autonomously to reconfigure the olfactory circuit by regulating a key chemoreceptor, odr-10, in the AWA neurons. Moreover, we find that odr-10 has a significant role in food detection, the regulation of which contributes to sex differences in behavioral prioritization. Overexpression of odr-10 increases male food attraction and decreases off-food exploration; conversely, loss of odr-10 impairs food taxis in both sexes. In larvae, both sexes prioritize feeding over exploration; correspondingly, the sexes have equal odr-10 expression and food attraction. Food deprivation, which transiently favors feeding over exploration in adult males, increases male food attraction by activating odr-10 expression. Furthermore, the weak expression of odr-10 in well-fed adult males has important adaptive value, allowing males to efficiently locate mates in a patchy food environment.
  
  
  CONCLUSIONS
  We find that modulated expression of a single chemoreceptor plays a key role in naturally occurring variation in the prioritization of feeding and exploration. The convergence of three independent regulatory inputs--somatic sex, age, and feeding status--on chemoreceptor expression highlights sensory function as a key source of plasticity in neural circuits.
authors.affiliation: Center for Neural Development and Disease, Department of Biomedical Genetics, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA.
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Ryan
authors.affiliation: Center for Neural Development and Disease, Department of Biomedical Genetics, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA; Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY 14642, USA.
authors.forename: Renee M
authors.initials: RM
authors.lastname: Miller
authors.affiliation: Center for Neural Development and Disease, Department of Biomedical Genetics, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA.
authors.forename: KyungHwa
authors.initials: K
authors.lastname: Lee
authors.affiliation: Department of Biology, National Center for Behavioral Genomics, Brandeis University, Waltham, MA 02454, USA.
authors.forename: Scott J
authors.initials: SJ
authors.lastname: Neal
authors.affiliation: Center for Neural Development and Disease, Department of Biomedical Genetics, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA.
authors.forename: Kelli A
authors.initials: KA
authors.lastname: Fagan
authors.affiliation: Department of Biology, National Center for Behavioral Genomics, Brandeis University, Waltham, MA 02454, USA.
authors.forename: Piali
authors.initials: P
authors.lastname: Sengupta
authors.affiliation: Center for Neural Development and Disease, Department of Biomedical Genetics, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA. Electronic address: douglas.portman@rochester.edu.
authors.forename: Douglas S
authors.initials: DS
authors.lastname: Portman
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D001522:Behavior, Animal; D017173:Caenorhabditis elegans / Q000378:metabolism / Q000502:physiology*; D002628:Chemoreceptor Cells / Q000378:metabolism*; D005260:Female; D006815:Hunger; D008297:Male; D012737:Sex Factors; D012726:Sexual Behavior, Animal; D013997:Time Factors