Characterization of the Mitochondrial DNA Control Region of the Wahoo, Acanthocybium solandri, from the Northcentral Gulf of Mexico and Bimini, Bahamas

Wahoo, Acanthocybium solandri, rank among the most coveted of fish sought by offshore recreational anglers in many parts of the world and are the basis of important commercial fisheries. Little information is available on the biology and life history of the wahoo and no information exists on the molecular genetics of this pelagic, circumglobally distributed species. Our preliminary research consisted of a molecular characterization of the mtDNA control region, including structure and sequence of the flanking tRNA genes. Total DNA was isolated from ten wahoo tissue samples: five from the northcentral Gulf of Mexico and five from Bimini, Bahamas. Universal primers produced a fragment of approximately 1830 base pairs (bp) containing the tRNAs for proline, threonine, and phenylalanine plus the entire control region of one fish from each site. The fragments were gel purified for direct sequencing and species specific primers were designed in the tRNAs immediately flanking the control region and used in subsequent amplifications. The control region of the ten wahoo ranged in size from 886 bp to 892 bp. One termination activation sequence (TAS I), three conserved sequence blocks (putative CSB I, CSB II, CSB III), five repeats, and two inverted repeats were identified. The 5' end of the control region contained the greatest sequence variability with approximately 100 variable bases and 3 indels within the first 330 bp. Multiple restriction sites for HinfI, RsaI, and SspI were identified that could be used to distinguish each fish as a unique haplotype by RFLP analysis. Results provide a characterization of the wahoo mtDNA control region for possible use in future investigations.