title: Genetic variability of the pattern of night melatonin blood levels in relation to coat changes development in rabbits.
abstract: To assess the genetic variability in both the nocturnal increase pattern of melatonin concentration and photoresponsiveness in coat changes, an experiment on 422 Rex rabbits (from 23 males) raised under a constant light programme from birth was performed. The animals were sampled at 12 weeks of age, according to 4 periods over a year. Blood samples were taken 7 times during the dark phase and up to 1 h after the lighting began. Maturity of the fur was assessed at pelting. Heritability estimates of blood melatonin concentration (0.42, 0.17 and 0.11 at mid-night, 13 and 15 h after lights-out respectively) and strong genetic correlations between fur maturity and melatonin levels at the end of the dark phase (-0.64) indicates that (i) the variability of the nocturnal pattern of melatonin levels is under genetic control and (ii) the duration of the nocturnal melatonin increase is a genetic component of photoresponsiveness in coat changes.
authors.affiliation: Station d'amélioration génétique des animaux, Institut national de la recherche agronomique, BP 27, 31326 Castanet Tolosan, France. allain@toulouse.inra.fr
authors.forename: Daniel
authors.initials: D
authors.lastname: Allain
authors.forename: Benoit
authors.initials: B
authors.lastname: Malpaux
authors.forename: François
authors.initials: F
authors.lastname: Puechal
authors.forename: René Gérard
authors.initials: RG
authors.lastname: Thébault
authors.forename: Hubert
authors.initials: H
authors.lastname: De Rochambeau
authors.forename: Philippe
authors.initials: P
authors.lastname: Chemineau
mesh_terms: D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology*; D014644:Genetic Variation; D006197:Hair / Q000502:physiology*; D008137:Longitudinal Studies; D008550:Melatonin / Q000097:blood* / Q000235:genetics; D017440:Photoperiod; D011817:Rabbits / Q000235:genetics* / Q000502:physiology; D011863:Radioimmunoassay
chemical_list: D008550:Melatonin