Allele specific-PCR and melting curve analysis showed relatively high frequency of ß-casein gene A1 allele in Iranian Holstein, Simmental and native cows.

There are two allelic forms of A1 and A2 of ß-casein gene in dairy cattle. Proteolytic digestion of bovine ß-casein A1 type produces bioactive peptide of ß-casomorphin-7 known as milk devil. ß-casomorphin-7 causes many diseases, including type 1 diabetes, cardiovascular disease syndrome, sudden death and madness. The aim of the present study was to determine the different allelic forms of ß-casein gene in Iranian Holstein, Simmental and native cattle in order to identify A1 and A2 variants. The blood samples were collected randomly and DNA was extracted using modified salting out method. An 854 bp fragment including part of exon 7 and part of intron 6 of ß-casein gene was amplified by allele specific polymerase chain reaction (AS-PCR). Also, the accuracy of AS-PCR genotyping has been confirmed by melting temperature curve analysis using Real-time PCR machinery. The comparison of observed allele and genotype frequency among the studied breeds was performed using the Fisher exact and Chi-squared test, respectively by SAS program. Obtained results showed the A1 allele frequencies of 50, 51.57, 54.5, 49.4 and 46.6% in Holstein, Simmental, Sistani, Taleshi and Mazandarani cattle populations, respectively. The chi-square test was shown that no any populations were in Hardy-Weinberg equilibrium for studied marker locus. Comparison and analysis of the test results for allelic frequency showed no any significant differences between breeds (P>0.05). The frequency of observed genotypes only differs significantly between Holstein and Taleshi breeds but no any statistically significant differences were found for other breeds (P>0.05). A relatively high frequency of ß-casein A1 allele was observed in Iranian native cattle. Therefore, determine the genotypes and preference alleles A2 in these native and commercial cattle is recommended.

Lack of association between the TNF-α-1031genotypes and generalized aggressive periodontitis disease.

Periodontal disease is one of the most prevalent inflammatory illnesses and is a main cause of tooth loss in human population. Tumor necrosis factor-α (TNF-α) gene is one of pro-inflammatory cytokines which has important role in pathogenesis of periodontal disease. The main purpose of this study is to determine genotype abundance of TNF-α-1031 gene in both groups of patients and controls, and also investigation of relation of single nucleotide polymorphism (SNP) these genotypes with periodontal disease risk. DNA was extracted from blood tissue of 31 patients and 54 controls. The TNF-α-1031 polymorphism was evaluated by polymerase chain reaction- confronting two-pair primer (PCR-CTPP) method. In the GAP group, the frequencies of TT, TC and CC genotypes were 35.48%, 61.29 and 3.23%, respectively. In controls the frequencies of TT, TC and CC genotypes were 22.22%, 72.22%, and 5.56%, respectively. Results of this study showed that there was no significant association between TNF-α (-1031 T/C promoter) gene polymorphisms and the risk of generalized aggressive periodontitis disease.