GMP, GCP & Quality Control

Biography

Biography: Sunil Kumar Verma

Abstract

Previously, the ‘Sushigate’ fish scandal of Florida and now the Europe-wide scandal over the contamination of beef products with horsemeat and, in some cases pork, has thrown the Food Standards Agency into the headlines. The methodology that revealed this scandal is mainly based on DNA barcoding of confiscated beef products involving amplification of small fragment of mitochondrial ‘Cytochrome b’ gene or ‘Cytochrome C Oxidase 1’ gene using universal primers.rnIt has been shown before that the Nuclear Mitochondrial Pseudogenes (numts) can introduce serious ambiguity into DNA barcoding results leading to false detection of many species in one. While amplifying the mitochondrial genomes of Bubalus bubalis (Buffalo) (Genbank Accession No. AF547270.1) and Platanista gangetica (Gangetic dolphin) using a universal primer system, we had detected a specific numt in dolphin DNA, which had high similarity scores with Sus (porcine) mitochondrial DNA rather than that with the dolphin mtDNA sequences available in nr nucleotide database of NCBI, leading to a serious confusion. On the first hand, we also suspected it to be a contamination of pig DNA in dolphin DNA preparations. However, careful re-analysis of the sequences identified this contaminating sequence as a numt, which might have had translocated and integrated to dolphin nuclear genome prior to the divergence of this species from Sus-Bovine lineage. Since the horse (Equus), pig, buffalo and dolphin all belong to Laurasiatheria lineage, the co-amplification of numt could also appear as contamination and adulteration of pig and horse in beef products. This, however, needs to be assessed and taken into consideration while DNA testing is done for food purity testing in particular by the use of DNA barcode system.