A 4-bp deletion in the ATP-binding cassette subfamily B member 1 (ABCB1) gene, also referred to as the multidrug resistance gene (MDR1), produces stop codons that cause premature termination of P-glycoprotein 1 (P-gp) synthesis. Dogs with the homozygous mutation do not express functional P-gp, which increases their sensitivity markedly to many common veterinary drugs. We detected the nt230 (del4) ABCB1 mutation in Border Collie dogs in western Mexico with a simple and affordable primer-introduced restriction analysis PCR (PIRA-PCR). PIRA-PCR clearly identified all genotypes in our sample of 104 dogs. Genotype frequencies were 0.952 (wild/wild), 0.029 (wild/mut) and 0.019 (mut/mut). Allele frequencies were 0.033 (mutant alleles) and 0.966 (wild-type alleles). In this small subset of the Mexican dog population, we found a higher prevalence of the nt230 (del4) MDR1/ABCB1 gene mutation than reported in other countries.

ATP 结合盒亚家族 B 成员 1 ( ABCB1 ) 基因（也称为多药耐药基因 ( MDR1 )）中的 4 bp 缺失会产生导致 P-糖蛋白 1 (P-gp) 合成提前终止的终止密码子. 具有纯合突变的狗不表达功能性 P-gp，这显着增加了它们对许多常见兽药的敏感性。我们检测到nt230 (del4) ABCB1使用简单且负担得起的引物引入限制性分析 PCR (PIRA-PCR) 在墨西哥西部的边境牧羊犬中进行突变。PIRA-PCR 清楚地识别了我们 104 只狗样本中的所有基因型。基因型频率为 0.952（野生/野生）、0.029（野生/突变）和 0.019（突变/突变）。等位基因频率为 0.033（突变等位基因）和 0.966（野生型等位基因）。在墨西哥犬群的这一小部分中，我们发现nt230 (del4) MDR1/ABCB1基因突变的患病率高于其他国家报道的。