Testing the Ability of DNA Markers to Resolve Species Boundaries

Abstract

DNA Barcoding is a useful tool in aiding researchers in identification, and classification of species by using short segments of DNA such as those found in mitochondria (eg. A portion of the COI gene). The COI gene sequence was used here first to characterize Tunisian populations of Ceratitis capitata from Bizerte, Tunisia and Takelsa, Tunisia. Comparisons were also made to species with very similar sequences found using the NCBI BLAST database. I have further evaluated whether COI is a good candidate DNA Barcode sequence for other genera by analyzing and comparing three collections of Bactrocera species endemic to the Philippines. These species belong to a very closely related complex of classified based on morphological characters. Sequence data can help resolve many issues relating to species complexes and tell us whether these samples appear to be different species, or whether they are so similar that perhaps they are actually one species.