Aim of our study was the optimization of a DNA method, that is appropriate for reliable, low cost identification of animal species in milk and dairy product (cheese) and to determine the ratio of species. Mitochondrial DNA was used in our work to analyse buffalo/cow milk mixtures contained different ratio of bovine milk such as 0.1%, 0.5%, 1%,...1.5%, 2%, 5%, 10%, 15% (v/v%). Buffalo cheese were produced using buffalo and cows milk (0%, 2%, 5%, 10%, 15% – v/v% cows milk in buffalo milk). In case of milk mixtures, using species specific primers, the PCR assay showed a 0.5 v/v% detection limit. Cattle, in the buffalo/cows milk 99.9/0.1 v/v% mixture, was not detectable. The identification of buffalo and cows DNA in cheese was successful. The intensity of eletroforetic PCR fragment indicated the increase of cow milk ratio in milk and cheese samples as well.
Pituitary adenylate cyclase-activating polypeptide is a neuropeptide expressed primarily in the hypothalamus and in other tissues, which divergent and extensive physiological functions are proved. Large number of SNPs in PACAP are published involved SNP that is associated with phenotypic trait of cattle as well. Hungarian Grey, Hungarian Simmen...tal, Holstein, Charolais and Angus cattle breeds were involved in this study to search for polymorphism in exon 5 1–391 bp and G/A transition. Our results of PCR RFLP and PCR SSCP did not prove the occurrence neither G/A transition, nor any other SNP in cattle breeds involved.
In our study PCR-temporal temperature gelelectrophoresis (TTGE) and MeltINGENY bioinformatic program were used to analyse the mutations in the genes of melanocortin-1 receptor (MC1R) and pituitary adenylate-cyclase activating polypeptide (PACAP) in cattle. Amplification of target DNA by PCR was performed with GC-clamp primers and non-GC-clamp p...rimers in simplex PCR reactions. The fragments were separated by denaturing polyacrylamide gelelectrophoresis (denaturing agents: high temperature, urea) after PCR reactions.MC1R homozygous individuals were used for the reaction.
We concluded that MeltINGENY program makes the decision and detection system easier, and more simple as the melting profile of target sequence is determined by the software. In case of MC1R gene, PCR-TTGE method is appropriate for SNP detection, however PACAP gene polymorphism can not be identified by the method, because PACAP mutations are not included in melting domains, therefore PCR-TTGE cannot detect them.