National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics and Breeding and Reproduction of Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, China.
J Anim Sci Biotechnol. 2012 Jul 23;3(1):24. doi: 10.1186/2049-1891-3-24.
Complex vertebral malformation (CVM) and bovine leukocyte adhesion deficiency (BLAD) are two autosomal recessive lethal genetic defects frequently occurring in Holstein cattle, identifiable by single nucleotide polymorphisms. The objective of this study is to develop a rapid and reliable genotyping assay to screen the active Holstein sires and determine the carrier frequency of CVM and BLAD in Chinese dairy cattle population.
We developed real-time PCR-based assays for discrimination of wild-type and defective alleles, so that carriers can be detected. Only one step was required after the DNA extraction from the sample and time consumption was about 2 hours. A total of 587 Chinese Holstein bulls were assayed, and fifty-six CVM-carriers and eight BLAD-carriers were identified, corresponding to heterozygote carrier frequencies of 9.54% and 1.36%, respectively. The pedigree analysis showed that most of the carriers could be traced back to the common ancestry, Osborndale Ivanhoe for BLAD and Pennstate Ivanhoe Star for CVM.
These results demonstrate that real-time PCR is a simple, rapid and reliable assay for BLAD and CVM defective allele detection. The high frequency of the CVM allele suggests that implementing a routine testing system is necessary to gradually eradicate the deleterious gene from the Chinese Holstein population.
复杂的椎体畸形（CVM）和牛白细胞黏附缺陷（BLAD）是两种常发生于荷斯坦牛的常染色体隐性致死遗传缺陷，可通过单核苷酸多态性识别。本研究旨在开发一种快速可靠的基因分型检测方法，筛选有活力的荷斯坦公牛，并确定中国奶牛群体中 CVM 和 BLAD 的携带频率。
我们开发了基于实时 PCR 的检测方法，用于区分野生型和缺陷型等位基因，从而可以检测到携带者。从样本中提取 DNA 后只需一步，耗时约 2 小时。对 587 头中国荷斯坦公牛进行了检测，鉴定出 56 名 CVM 携带者和 8 名 BLAD 携带者，杂合子携带者频率分别为 9.54%和 1.36%。系谱分析表明，大多数携带者可以追溯到共同的祖先，BLAD 为 Osborndale Ivanhoe，CVM 为 Pennstate Ivanhoe Star。
这些结果表明，实时 PCR 是一种简单、快速和可靠的 BLAD 和 CVM 缺陷等位基因检测方法。CVM 等位基因的高频率表明，有必要实施常规检测系统，逐步从中国荷斯坦牛群体中消除有害基因。
