Ceriotti G, Chessa S, Bolla P, Budelli E, Bianchi L, Duranti E, Caroli A
Dipartimento di Scienze e Tecnologie Veterinarie per la Sicurezza Alimentare, Università degli Studi di Milano, 20134 Milano, Italy.
J Dairy Sci. 2004 Aug;87(8):2606-13. doi: 10.3168/jds.S0022-0302(04)73386-X.
Casein genetic polymorphisms are important and well known due to their effects on quantitative traits and technological properties of milk. At the DNA level, polymerase chain reaction (PCR)-single-strand conformation polymorphism (SSCP) allows for the simultaneous typing of several alleles at casein loci, as well as the detection of unknown polymorphisms. Here we describe the usefulness of the PCR-SSCP technique for casein typing in sheep. In particular, three single-nucleotide polymorphisms (SNP) are described at CSN1S1, CSN2, and CSN3, all resulting in amino acid exchanges. At CSN1S1, a transition T-->C was found, resulting in the deduced amino acid exchange Ile186-->Thr186. A transition A-->G resulting in the deduced amino acid exchange Met183-->Val183 was identified at CSN2. The 2 SNP showed a rather high frequency (ranging from 0.12 to 0.26) in 3 Italian breeds (Sarda, Comisana, Sopravissana). Another transition C-->T (Ser104-->Leu104) was found at CSN3 in one heterozygous animal.
酪蛋白基因多态性因其对牛奶数量性状和技术特性的影响而非常重要且广为人知。在DNA水平上，聚合酶链反应（PCR）-单链构象多态性（SSCP）可同时对酪蛋白基因座的多个等位基因进行分型，还能检测未知的多态性。在此，我们描述了PCR-SSCP技术在绵羊酪蛋白分型中的实用性。具体而言，在CSN1S1、CSN2和CSN3上描述了三个单核苷酸多态性（SNP），均导致氨基酸交换。在CSN1S1上，发现了一个T→C的转换，导致推导的氨基酸交换Ile186→Thr186。在CSN2上鉴定出一个A→G的转换，导致推导的氨基酸交换Met183→Val183。这两个SNP在三个意大利品种（撒丁岛羊、科米萨纳羊、索普拉维萨纳羊）中显示出相当高的频率（范围为0.12至0.26）。在一只杂合动物的CSN3上发现了另一个C→T的转换（Ser104→Leu104）。
