title: Sex differences in diurnal rhythms of food intake in mice caused by gonadal hormones and complement of sex chromosomes.
abstract: We measured diurnal rhythms of food intake, as well as body weight and composition, while varying three major classes of sex-biasing factors: activational and organizational effects of gonadal hormones, and sex chromosome complement (SCC). Four Core Genotypes (FCG) mice, comprising XX and XY gonadal males and XX and XY gonadal females, were either gonad-intact or gonadectomized (GDX) as adults (2.5months); food intake was measured second-by-second for 7days starting 5weeks later, and body weight and composition were measured for 22weeks thereafter. Gonadal males weighed more than females. GDX increased body weight/fat of gonadal females, but increased body fat and reduced body weight of males. After GDX, XX mice had greater body weight and more fat than XY mice. In gonad-intact mice, males had greater total food intake and more meals than females during the dark phase, but females had more food intake and meals and larger meals than males during the light phase. GDX reduced overall food intake irrespective of gonad type or SCC, and eliminated differences in feeding between groups with different gonads. Diurnal phase of feeding was influenced by all three sex-biasing variables. Gonad-intact females had earlier onset and acrophase (peak) of feeding relative to males. GDX caused a phase-advance of feeding, especially in XX mice, leading to an earlier onset of feeding in GDX XX vs. XY mice, but earlier acrophase in GDX males relative to females. Gonadal hormones and SCC interact in the control of diurnal rhythms of food intake.
authors.affiliation: Department of Integrative Biology & Physiology, University of California, Los Angeles, CA, USA; Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, CA, USA. Electronic address: xuqichen@physci.ucla.edu.
authors.forename: Xuqi
authors.initials: X
authors.lastname: Chen
authors.affiliation: CURE/Digestive Diseases Research Center and Center for the Neurobiology of Stress, Department of Medicine, Division of Digestive Diseases, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; VA Greater Los Angeles Healthcare System, 11301 Wilshire Blvd, Los Angeles, CA, 90073, USA. Electronic address: LixinWang@mednet.ucla.edu.
authors.forename: Lixin
authors.initials: L
authors.lastname: Wang
authors.affiliation: Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, CA, USA; Department of Psychiatry and Biobehavioral Sciences, Semel Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA. Electronic address: hloh@mednet.ucla.edu.
authors.forename: Dawn H
authors.initials: DH
authors.lastname: Loh
authors.affiliation: Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, CA, USA; Department of Psychiatry and Biobehavioral Sciences, Semel Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA. Electronic address: ccolwell@mednet.ucla.edu.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Colwell
authors.affiliation: CURE/Digestive Diseases Research Center and Center for the Neurobiology of Stress, Department of Medicine, Division of Digestive Diseases, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; VA Greater Los Angeles Healthcare System, 11301 Wilshire Blvd, Los Angeles, CA, 90073, USA. Electronic address: ytache@mednet.ucla.edu.
authors.forename: Yvette
authors.initials: Y
authors.lastname: Taché
authors.affiliation: Department of Human Genetics and Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles CA, USA. Electronic address: reuek@ucla.edu.
authors.forename: Karen
authors.initials: K
authors.lastname: Reue
authors.affiliation: Department of Integrative Biology & Physiology, University of California, Los Angeles, CA, USA; Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, CA, USA. Electronic address: arnold@ucla.edu.
authors.forename: Arthur P
authors.initials: AP
authors.lastname: Arnold
mesh_terms: D000818:Animals; D001823:Body Composition / Q000502:physiology; D001835:Body Weight; D002940:Circadian Rhythm / Q000235:genetics; D004435:Eating / Q000235:genetics / Q000502:physiology*; D005260:Female; D005838:Genotype; D042341:Gonadal Hormones / Q000097:blood*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D012727:Sex Characteristics; D012730:Sex Chromosomes / Q000502:physiology*; D012737:Sex Factors
chemical_list: D042341:Gonadal Hormones
keywords: Adiposity; Body composition; Circadian rhythm; Estradiol; Food intake; Four Core Genotypes; Night eating; Obesity; Sex chromosomes; Sex differences; Testosterone