利用单链构象多态性检测牛白细胞黏附缺陷症方法的建立

牛白细胞黏附缺陷症(BLAD)是由常染色体上CD18基因单碱基突变(A→G)引起的隐性遗传疾病，隐性基因纯合时导致白细胞表面的β2整合素表达明显减少或缺乏而引起临床发病，患病牛的主要特征是机体免疫力降低、易患病从而影响其生产性能的表现，严重影响了奶牛场的经济效益。该工作利用自行设计的特异性PCR引物，通过对PCR、PCR-SSCP条件的筛选和优化，并结合DNA序列测定，建立了PCR-SSCP检测BLAD 有害基因的新方法，该方法简便快捷、准确率高，使用样品宽泛，适合大样本筛选，为奶牛BLAD有害基因的分型和筛选提供了新的方法和思路，为我国奶牛的分子选育提供了可靠的理论依据。

A method for detecting bovine leukocyte adhesion deficiency in Hol-stein calves using polymerase chain reaction-single strand conforma-tion polymorphism analysis

Bovine leukocyte adhesion deficiency (BLAD) is an autosomal recessive disease caused by A-->G mutation in the CD18 gene. The disease is characterized by greatly reduced expression of the heterodimeric beta2 integrin adhesion molecules on leukocytes, resulting in multiple defects in leukocyte function and significant deficits on performance traits in Holstein cattle. In this study, primers were designed to amplify the CD18 gene fragment and BLAD was detected by PCR-SSCP in a simple, highly accurate and high throughput manner. Results were confirmed by DNA sequencing. This study provides a more reliable and useful method for extensive screening of BLAD and also offers a theoretical basis for molecular diagnosis in Holstein calves.