DNA Barcoding - Choice of Locus

Choice of Locus

A desirable locus for DNA barcoding should be standardized (so that large databases of sequences for that locus can be developed), present in most of the taxa of interest and sequencable without species-specific PCR primers, short enough to be easily sequenced with current technology, and provide a large variation between species yet a relatively small amount of variation within a species.

Although several loci have been suggested, a common set of choices are:

• For animals and many other eukaryotes, the mitochondrial CO1 gene

• For land plants, the concatenation of the rbcL and matK chloroplast genes