tailieunhanh - Báo cáo sinh học: " Genetic variability of the pattern of night melatonin blood levels in relation to coat changes development in rabbits"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học thế giới đề tài: Genetic variability of the pattern of night melatonin blood levels in relation to coat changes development in rabbits | Genet. Sel. Evol. 36 2004 207-216 INRA EDP Sciences 2004 DOI gse 2003059 207 Original article Genetic variability of the pattern of night melatonin blood levels in relation to coat changes development in rabbits Daniel ALLAiNa Benoit MALPAUxb Francois PuECHALa Rene Gerard ThEbaultc Hubert de RocHAMBEAUa Philippe CHEMINEAUb a Station d amelioration genetique des animaux Institut national de la recherche agronomique BP 27 31326 Castanet Tolosan France b Physiologie de la reproduction et des comportements neuroendocrinologie Institut national de la recherche agronomique 37380 Nouzilly France c Genetique animale phaneres Le Magneraud Institut national de la recherche agronomique BP 56 17700 Surgeres France Received 6 June 2002 accepted 25 September 2003 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 and 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 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. rabbit coat development melatonin secretion genetic variability 1. INTRODUCTION The pineal gland via melatonin secretion is a key element in the neuroendocrine control of pelage changes by photoperiodism in various mammalian species including mink sheep goats and rabbits 1 as it is for