New cyt b gene universal primer set for forensic analysis.

Area of Science:

• Forensic Science
• Molecular Biology
• Genetics

Background:

• Mitochondrial DNA (mtDNA), specifically the cytochrome b (cyt b) gene, is crucial for species identification in forensic science.
• Degraded DNA samples pose challenges for accurate species identification, necessitating efficient amplification tools.

Purpose of the Study:

• To develop a new universal primer set for the cytochrome b gene with high species identification capabilities, even in degraded DNA.
• To validate the primer set's effectiveness across diverse mammalian and non-mammalian species and assess its performance on forensic samples.

Main Methods:

• Designed universal primers by aligning 751 mammalian cyt b sequences from GenBank to identify a variable region flanked by conserved sequences.
• Tested primer efficacy on 63 animal species across 5 classes, analyzing intraspecific variability using BLAST, and constructing phylogenetic trees.
• Evaluated primer performance on 40 degraded forensic DNA samples.

Main Results:

• The new primer set successfully identified species in all 63 tested animal species.
• Intraspecific concordance exceeded 97%, and phylogenetic analysis showed 93.75% of species grouped correctly by Order.
• Species identification was achieved even with highly degraded DNA from forensic samples.

Conclusions:

• The developed universal cyt b primer set is highly effective for species identification, particularly in forensic applications involving degraded DNA.
• The primer set offers robust species discrimination power and high intraspecific concordance, making it a valuable tool for forensic analysis.
• This new primer set addresses a critical need for reliable species identification in challenging forensic sample types.