Project to Obtain Butterfly DNA through Wing Swabs Wraps Up

Our Department of Defense Legacy Program Grant (Project 12-608) to develop a technique to sample DNA from live butterflies has wrapped up. The project was a collaboration with Dr. Jana Johnson at Moorpark College, Dr. Bob Wayne’s lab at UCLA, and a couple of groups working with endangered butterflies around the country.

The objective of the project was to develop and test a technique to sample DNA from live butterflies without removing a portion of the body (wing or leg clips) to increase feasibility of genetic testing for species being managed on military lands.

The longevity of Palos Verdes blue butterflies that were swabbed for DNA, handled but not swabbed, and neither handled nor swabbed did not differ significantly.

The longevity of Palos Verdes blue butterflies that were swabbed for DNA, handled but not swabbed, and neither handled nor swabbed did not differ significantly.

We developed an illustrated guide to sampling the wing scales of butterflies with a small cotton swab and distributed this guide to species experts working on three butterfly species currently or formerly found on military installations. These technicians sampled butterflies either in the wild or in captive breeding situations. We tested the effect of handling and sampling on longevity of captive Palos Verdes blue butterfly from a local military installation by comparing sampled, handled only, and control butterflies. We attempted to extract DNA from all swabs and in addition developed a microsatellite library for the Saint Francis Satyr from whole-body samples because such a library was not previously available. We then compared the success of DNA extraction across species and the differences between survival patterns of Palos Verdes blue butterfly in the experiment.

The new technique resulted in obtaining mitochondrial DNA from all butterflies sampled in captivity (Palos Verdes blue and Taylor’s checkerspot) but only a portion of those sampled in the wild (71% of Saint Francis satyrs and 15% of Oregon silverspots). Nuclear DNA was not amplified from the samples although this should be possible. We showed that handling butterflies for this purpose does not affect longevity in a captive environment and that technicians with no previous experience with the technique can implement it from written instructions only. As an additional benefit we developed a library of candidate microsatellite markers for Saint Francis Satyr, an extremely rare butterfly located exclusively on a military installation.

I’m going to hold off posting the final report for a while as we pursue some further tests and prepare for publication.  The report citation is:  Longcore, T. 2014. Demonstration of a non-destructive technique to sample DNA from butterflies. Department of Defense Legacy Program, Project 12-608.  This is only a temporary source, the paper still in progress will also include authors Jana J. Johnson, Deb Pires, Sarah A. Hendricks, Sarah Wenner, John Pollinger, and Robert K. Wayne.