earticle

영어

Animal-related crimes have emerged as a social issue with an increase in the number of pets, and the importance of accurate animal species identification using DNA from crime scene evidence is augmenting. This study investigated the species-specific limitations of universal primers, commonly employed in forensic casework, through a discordant result from a casework sample. Analysis of an evidence sample containing a mixture of human and feline DNA revealed that while 12S sequencing yielded a mixed profile, the Cyt b primer exclusively amplified the human DNA. Subsequent analysis to resolve this discordance demonstrated that the Cyt b primer exhibited a greater number of nucleotide mismatches within its binding region on cat DNA, particularly at the 3' terminus and internal regions, compared to human DNA. This structural incompatibility critically compromised amplification efficiency for the feline DNA template. This finding highlighted a significant forensic limitation, as the use of the Cyt b universal primer alone could lead to the failure of feline DNA detection. To address this issue, the applicability of a feline-specific primer (SFI14-Cat) was validated. This study proves that the Cyt b universal primer can exhibit low amplification efficiency for certain species such as cat. Therefore, it suggests that using a species-specific primer in conjunction with a universal primer is essential for enhancing the accuracy and reliability of forensic analysis for species identification in future animal-related crime cases.