Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: Polymorphism of β-casein in the Creole goat of Guadeloupe: evidence for a null allele | Genet Sei Evol 1993 25 403-408 Elsevier INRA 403 Note Polymorphism of 3-casein in the Creole goat of Guadeloupe evidence for a null allele MF Mahé F Grosclaude Institut National de la Recherche Agronomique Laboratoire de Génétique Biochimique 78352 Jouy-en-Josas cedex France Received 6 January 1993 accepted 3 February 1993 Summary - A polymorphism of 3-casein including several null phenotypes was observed in a large flock of Creole goats of Guadeloupe. In addition to the common allele -CnA this polymorphism includes 2 new alleles 3-CnB with a frequency of and 3-Cn a null allele with a frequency of . The null allele was found in 2 different Osi-Cn 3-Cn haplotypes asi-CnB d-Cn and ữsl-CnA 3 - Cn . This suggests the possible existence of 2 different mutations producing a null allele at locus 3-Cn. goat -casein polymorphism null type Resume Polymorphisme de la caséine 3 dans un troupeau de chèvres créoles de Guadeloupe mise en evidence d un allèle nul. Un polymorphisme de la caséine 3 comprenant entre autres plusieurs phenotypes nuls a été observe dans un grand troupeau de chèvres créoles de Guadeloupe. Ce polymorphisme s explique par la presence en plus de 1 allèle commun -CnA de 2 nouveauxv allèles -CnB frequence 0 03 et P-Cn un allele nul frequence d environ 0 2 . L allele nul a été trouvé dans 2 haplotypes Qsi-Cn 3-Cn differents asi-CnB 3-Cn et asi-CnA 3-Cn ce qui suggère I existence possible de 2 mutations de type nul au locus 3-Cn. chèvre caséine 3 polymorphisme allele nul INTRODUCTION Among the 4 types of casein 3 have been found to be polymorphic in the goat namely asi- as2 and K-caseins. Boulanger et al 1984 were the first to describe the polymorphism of as2-casein with 2 alleles as2-CnA and as2-CnB the first being predominant in the Alpine and Saanen breeds. Later studies in other breeds 404 MF Mahé F Grosclaude indicated that this polymorphism was widely distributed Grosclaude and Tucker 1992 . The polymorphism of asi-casein also disclosed by .
