DNA Barcoding is a molecular approach to identifying groups of organisms using gene sequences. A gene useful for DNA barcoding at the species level should be highly conserved among a wide range of taxonomic groups yet just variable enough that a species??? gene pool contains one unique allele that differs from other species??? alleles. A gene that has been useful for this purpose in plants is rbcL which codes for the large subunit of ribulose 1,5 bisphosphate carboxylase/oxygenase (Rubisco), an enzyme used in photosynthesis. We have developed a lab activity that introduces students to the Barcode of Life (BOL) Project while teaching them basic skills in both the laboratory and computer-based bioinformatics. Starting with a mix of salad greens obtained from a supermarket, each student pair selects a leaf and follows a protocol involving extraction of DNA, polymerase chain reaction (PCR), cleanup of rbcL amplicons, and set-up of sequencing reactions that are sent away to be processed. Once each student receives their DNA sequence, that sequence can then be BLASTed to reveal the most probable candidate species in the NCBI database. If students have collectively sampled a variety of different leaves, they can do pairwise BLAST comparisons of sequences obtained from both the same type of leaf and different types to assess the usefulness of the rbcL gene for DNA Barcoding among plants. Distance Trees can also be created to investigate phylogenetic relationships.
Keywords: DNA barcoding in plants, Barcode of Life, molecular genetics, bioinformatics, BLAST, phylogeny
University of Manitoba (2025)
We use cookies to ensure that we give you the best experience on our website. If you continue to use this site we will assume that you are happy with it.
