Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: A Mendelian polymorphism underlying quantitative variations of goat α -casein s1 | Génét. Sél. Evol. 1987 19 4 399-412 A Mendelian polymorphism underlying quantitative variations of goat as1-casein F. GROSCLAUDE Marie-Frangoise MAHÉ Ghislaine BRIGNON Liliana DI STASIO and R. JEUNET . Laboratoire de Genetique Biochimique Centre de Jouy-en-Josas F 78350 Jouy-en-Josas . Laboratoire de Biochimie et Technologie Laitières Centre de Jouy-en-Josas F 78350 Jouy-en-Josas Osservatorio di Genetica Animate Via Pastrengo 28 10128 Torino Italie . Station Expérimentale Laitière . 94 F 39800 Poligny Summary Using SDS-polyacrylamide gel electrophoresis and rocket immunoelectrophoresis 3 new alleles designated asl-CnB asl-CnF and asl-Cn were identified at the goat as -Cn locus in addition to alleles asl-CnA asl-CnB and asl-Cnc previously reported by Boulanger et al. 1984 . Alleles asl-CnA as -CnB and a5 -Cnc are associated with a high content of asl-casein approximate mean contribution of each allele being g 1 compared to a -CnF with a low content g 1 and asl-CnB with an intermediate content g 1 asl-Cn appears to be a true null allele. In a sample of 213 Alpine females from 49 flocks in West Central France the frequencies of the 6 alleles were asl-CnA asl-CnB a5l-Cnc a -CnB asl-CnF and asl-Cn . In a sample of 159 Saanen females from 52 flocks of the same region the frequencies were asl-CnA asl-CnB asl-Cnc 0 asl-CnB asl-CnF asl-Cn . Additional data confirm that loci sl-Cn and as2-Cn are closely linked. Preliminary investigations indicated a significant superiority in casein content of milks from goats possessing the allele asl-CnA as compared to that of milks from goats of genotypes asl-CnF as -CnF and asl-CnB asl-CnF and in a large herd N 251 a strong correlation was observed between the asl-casein content and the rennet-casein content of milk r b . Key words Goat asl-casein as2-casein polymorphism null type genetic linkage quantitative variations. Résumé Un .