Polymorphism of ZuBeCa3 microsatellite and its association with mammary tumor in dogs

A study was conducted to explore the genetic polymorphism at ZuBeCa3 microsatellite and to estimate the association between microsatellite polymorphism and mammary cancer in dogs. Three genotypes namely AA, AB and BB were observed both in dogs affected by mammary cancer and in non-affected dogs. In the affected group, the frequency of genotype and allele was 0.63 for AA, 0.25 for AB and 0.12 for BB genotype, and 0.76 for A and 0.24 for B allele. In the nonaffected group, the frequency of AA, AB and BB genotype was 0.39, 0.38 and 0.23 and the frequency of A and B allele was 0.58 and 0.42, respectively. Histopathological observation classified the cancer-affected animals into three groups namely, malignant solid mammary carcinoma, malignant papillary adenocarcinoma and benign papillary adenoma in which the frequency of A allele was relatively more predominant in benign tumor group, which is more than 80%. Statistical tests showed significant differences (P < 0.01) of allelic distribution between tumor-affected and non-affected group, which reveals the effect of polymorphism on occurrences of mammary cancer in dogs. Besides, chi(2) test also reflected the significant effect of genotypes on occurrences of three groups of mammary cancer in dogs.