Genetic variability of the pattern of night melatonin blood levels in relation to coat changes development in rabbits |
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Authors: | Daniel Allain Benoit Malpaux Fran?ois Puechal René Gérard Thébault Hubert de Rochambeau Philippe Chemineau |
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Institution: | 1.Station d''amélioration génétique des animaux, Institut national de la recherche agronomique, BP 27, 31326 Castanet Tolosan, France;2.Physiologie de la reproduction et des comportements, neuroendocrinologie, Institut national de la recherche agronomique, 37380 Nouzilly, France;3.Génétique animale phanères, Le Magneraud, Institut national de la recherche agronomique, BP 56, 17700 Surgères, France |
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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. |
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Keywords: | rabbit coat development melatonin secretion genetic variability |
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