Veterinary/zoology session

The assessment of sequence variability in vertebrate mitochondrial genomes is recently the subject of many phylogenetical studies as well as a potential tool in animal breeding, in veterinary and in forensic sciences. The advantage of investigating mitochondrial DNA in animal breeding, in quality control and in forensic cases is based on its high copy number in the cell which makes it possible to be examined in highly degraded samples as well.

In our recent study we assessed the sequence polymorphisms of the mitochondrial DNA control region (D-loop) in Hungarian domestic (Sus scrofa domestica) and in wild pigs (Sus scrofa). The study involved the following breeds: Hungarian Landrace, Large White, Pietrain, Blond-, Red- and Swallow-bellied Mangalica, and Hungarian wild-boars as well. A part of the D-loop has been sequenced from the blood samples of altogether forty animals, from which 5-5 belonged to different breeds and ten originated from the Hungarian wild pigs. A 239 bp DNA fragment of the D-loop (from 16441 to 16680 nucleotide positions) was amplified by PCR and directly sequenced using the conventional Sanger dideoxy sequencing method in each DNA samples.

Comparing the D-loop sequences of the different swine breeds we found the Asian type 16594C, 16601G, 16651C sequence motif in five from altogether ten of the Large White and Hungarian Landrace breeds. In the Pietrain, in the Mangalica and in the wild pigs European type sequences were found exclusively. Interestingly, in many of the Hungarian autochthonous Mangalicas a newly reviewed nucleotide variant 16667A has been identified, which could establish a breed-specific polymorphism. This Mangalica specific polymorphic locus has to be confirmed by further population studies.