DNA samples were extracted from sixteen unidentified shark tissue specimens and underwent PCR amplification of CO1 mitochondrial gene. DNA samples were assessed for presence and quality using agarose gel electrophoresis. Species identification was performed by importing finalized CO1 sequences into two DNA databases to ensure accurate identification. Phylogenic analysis was then conducted to determine relationships between identified species.
Electrophoresis
Electrophoresis of DNA run in 2% agarose gel showed successful extraction of DNA in samples 1-8, 12 and 14-16. Samples were of good quality with high molecular weights (Figure 2). Samples 11 and 13 in Row 1 of gel 2 were not easily visible and thus the molecular weight was difficult to …show more content…
Relatedness between C. limbatus, C. tilstoni and C. obscurus is observed, indicating they shared a recent common ancestor (Fig 1.). The relative distance of I. oxyrinchus and S. australis from the shared common ancestor between shark species is indicative of their genetic divergence from the other samples (Fig. 1). Also noted there was significant genetic ambiguity between C. limbatus and C. tilstoni according to BOLD results. Genetic ambiguity was also noted between C. obscurus …show more content…
limbatus and C. tilstoni, suggesting that these species are very closely related and that they only diverged from each other approximately 200,000 years ago (Wong et al., 2009). The presence of CO1 haplotypes shared between C. limbatus and C. tilstoni also suggest the two shared a recent common ancestor and thus may explain why analyzing CO1 results of the two species resulted in our ambiguous BOLD Systems results (Boomer et al., 2010). Similar research into C. obscurus indicate that it is very similar genetically to Carcharhinus galapagensis (Galapagos shark), suggesting that the two derived from a common ancestor very recently as well and this may explain why it was difficult in definitively distinguishing between the four samples (Benavides et al., 2011). These ambiguity issues could perhaps be circumvented in future experiments by sequencing other genes in addition to the mitochondrial CO1 gene when identifying shark
Electrophoresis
Electrophoresis of DNA run in 2% agarose gel showed successful extraction of DNA in samples 1-8, 12 and 14-16. Samples were of good quality with high molecular weights (Figure 2). Samples 11 and 13 in Row 1 of gel 2 were not easily visible and thus the molecular weight was difficult to …show more content…
Relatedness between C. limbatus, C. tilstoni and C. obscurus is observed, indicating they shared a recent common ancestor (Fig 1.). The relative distance of I. oxyrinchus and S. australis from the shared common ancestor between shark species is indicative of their genetic divergence from the other samples (Fig. 1). Also noted there was significant genetic ambiguity between C. limbatus and C. tilstoni according to BOLD results. Genetic ambiguity was also noted between C. obscurus …show more content…
limbatus and C. tilstoni, suggesting that these species are very closely related and that they only diverged from each other approximately 200,000 years ago (Wong et al., 2009). The presence of CO1 haplotypes shared between C. limbatus and C. tilstoni also suggest the two shared a recent common ancestor and thus may explain why analyzing CO1 results of the two species resulted in our ambiguous BOLD Systems results (Boomer et al., 2010). Similar research into C. obscurus indicate that it is very similar genetically to Carcharhinus galapagensis (Galapagos shark), suggesting that the two derived from a common ancestor very recently as well and this may explain why it was difficult in definitively distinguishing between the four samples (Benavides et al., 2011). These ambiguity issues could perhaps be circumvented in future experiments by sequencing other genes in addition to the mitochondrial CO1 gene when identifying shark