The use of mitochondrial DNA genes to identify closely related avian species

Species identification using mitochondrial DNA (mtDNA) loci is a standard method for mammalian species testing. Less is understood about the conservation and variability in the avian mitochondrial genome, yet many exotic bird species are threatened with extinction and are traded illegally. In this study 80 different avian species were chosen from 22 different Orders and their gene sequences for the cytochrome b, cytochrome oxidase I and the ND2 genes were obtained from the NCBI web site. Alignments of the sequence determined the areas of greatest variation and conservation. The alignment result of DNA sequence showed that the cytochrome b gene placed the most number of avian species into their appropriate Orders, ND2 was next closest and COI the poorest of the three loci. These data support the use of cytochrome b over the other two mitochondrial loci for avian species identification

DNA typing in wildlife crime : recent developments in species identification

Species identification has become a tool in the investigation of acts of alleged wildlife crimes. This review details the steps required in DNA testing in wildlife crime investigations and highlights recent developments where not only can individual species be identified within a mixture of species but multiple species can be identified simultaneously. ‘What species is this?’ is a question asked frequently in wildlife crime investigations. Depending on the material being examined, DNA analysis may offer the best opportunity to answer this question. Species testing requires the comparison of the DNA type from the unknown sample to DNA types on a database. The areas of DNA tested are on the mitochondria and include predominantly the cytochrome b gene and the cytochrome oxidase I gene. Standard analysis requires the sequencing of part of one of these genes and comparing the sequence to that held on a repository of DNA sequences such as the GenBank database. Much of the DNA sequence of either of these two genes is conserved with only parts being variable. A recent development is to target areas of those sequences that are specific to a species; this can increase the sensitivity of the test with no loss of specificity. The benefit of targeting species specific sequences is that within a mixture of two of more species, the individual species within the mixture can be identified. This identification would not be possible using standard sequencing. These new developments can lead to a greater number of samples being tested in alleged wildlife crimes