Species Identification Using Cytochrome B Gene

Lee, Soong Deok; Lee, Yoon Seong; Lee, Jung Bin

Abstract

The feasibility of species identification using sequence analysis of the cytochrome B (Cyt B) gene in mitochondrial DNA was investigated. DNA was extracted from nine different animals that could be easily met in our surroundings and Cyt B gene was amplified. Direct sequencing results for the amplified PCR products were compared with each other. Human was also included. Nucleotide sequence of the Cyt B gene for each animals was also compared with the previously known ones registered in nucleotide databases, Genebank. The inter-species sequence variation was high as the percent similarity of each sequences ranged 64.6-83.5%. Compared to this the percent similarity of sequences obtained here were high when compared to the sequences of the same species registered in the database showing relatively low intra-species variation. This data shows that the nucleotide sequences of Cyt B gene in a certain biological materials can be identified at species level. The applicability of this method to the forensic field is also demonstrated by performing a casework; determination of the origin for the placentae which were commercial available as "invogorant". Points about the use of Cyt B gene in forensic field was also reviewed.