DNA synapomorphies for a variety of taxonomic levels from a cosmid library from the New World bat Macrotus waterhousii.

An effective method yielding taxon-specific markers from the genome of a single individual would be valuable for many types of scientific investigations, including systematic, forensic, conservation, and evolutionary studies. We explored the use of cosmid libraries, with insert sizes averaging 35 kb, to streamline the process of locating sequences of DNA that can serve as taxonomic markers from the specific to the ordinal levels. By screening approximately 2.6% of the leaf-nosed bat (Macrotus waterhousii) genome, we identified several potential DNA fragments that appear to be synapomorphic for a variety of taxonomic levels. A more thorough analysis of the markers documented that 17 Macrotus-specific clones represent three distinct DNA generic markers, whereas 30 microchiropteran clones represent multiple copies of a single family of repetitive DNA. The Microchiroptera taxon markers hybridize with representatives of most of the Microchiroptera families; however, no hybridization was detected for members of the superfamily Rhinolophoidea. These results demonstrate that cosmid libraries can be a valuable source for isolating taxon-specific markers from mammals even when the insert size is as large as 35 kb.