title: Quantitative Genetics of the Aging of Reproductive Traits in the Houbara Bustard.
abstract: Do all traits within an organism age for the same reason? Evolutionary theories of aging share a common assumption: the strength of natural selection declines with age. A corollary is that additive genetic variance should increase with age. However, not all senescent traits display such increases suggesting that other mechanisms may be at play. Using longitudinal data collected from more than 5400 houbara bustards (Chlamydotis undulata) with an exhaustive recorded pedigree, we investigated the genetics of aging in one female reproductive trait (egg production) and three male reproductive traits (courtship display rate, ejaculate size and sperm viability), that display senescence at the phenotypic level. Animal models revealed an increase in additive genetic variance with age for courtship display rate and egg production but an unexpected absence of increased additive genetic variance for ejaculate size and no additive genetic variance for sperm viability. Our results suggest that the mechanisms behind the senescence of some traits are linked with a change in genetic expression, whereas for some other traits, aging may result from the constraints associated with physiological wear and tear on the organism throughout the life of the individual.
authors.affiliation: UMR 7204 MNHN-CNRS-UPMC Centre d'Ecologie et des Sciences de la Conservation, Muséum National d'Histoire Naturelle, Paris, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Chantepie
authors.affiliation: UMR 7204 MNHN-CNRS-UPMC Centre d'Ecologie et des Sciences de la Conservation, Muséum National d'Histoire Naturelle, Paris, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Robert
authors.affiliation: UMR CNRS/uB 6282 Biogéosciences, Université de Bourgogne, Dijon, France.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Sorci
authors.affiliation: Reneco for Wildlife Preservation, Abu Dhabi, United Arab Emirates.
authors.forename: Yves
authors.initials: Y
authors.lastname: Hingrat
authors.affiliation: UMR 5175 CEFE-CNRS Centre d'Ecologie Fonctionnelle et Evolutive, Montpellier, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Charmantier
authors.affiliation: Emirates Center for Wildlife Propagation, Missour, Morocco.
authors.forename: Gwénaëlle
authors.initials: G
authors.lastname: Leveque
authors.affiliation: Reneco for Wildlife Preservation, Abu Dhabi, United Arab Emirates.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Lacroix
authors.affiliation: UMR 7204 MNHN-CNRS-UPMC Centre d'Ecologie et des Sciences de la Conservation, Muséum National d'Histoire Naturelle, Paris, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Teplitsky
mesh_terms: D000375:Aging / Q000235:genetics*; D000818:Animals; D001717:Birds / Q000502:physiology*; D052284:Clutch Size; D003380:Courtship; D056727:Endangered Species; D005260:Female; D014644:Genetic Variation; D008137:Longitudinal Studies; D008297:Male; D008957:Models, Genetic; D009018:Morocco; D012098:Reproduction / Q000235:genetics*; D012661:Semen / Q000502:physiology; D012726:Sexual Behavior, Animal; D013094:Spermatozoa / Q000502:physiology