ARS | Publication request: DNA Amplification from Pin Mounted Bumble Bees (Bombus) in a Museum Collection: Effects of Fragment Size and Specimen Age on Successful PCR

Submitted to: Apidologie
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 15, 2008
Publication Date: March 15, 2009
Citation: Strange, J.P., Knoblett, J.N., Griswold, T.L. 2009. DNA Amplification from Pin Mounted Bumble Bees (Bombus) in a Museum Collection: Effects of Fragment Size and Specimen Age on Successful PCR. Apidologie 40:134-139.

Interpretive Summary: Entomological collections contain large numbers of pinned insect specimens and offer the potential to determine changes in genetic diversity over time. We assayed DNA markers (microsatellites) widely used in genetic studies for usefulness in studying pinned bumble bee specimens from the U.S. National Pollinating Insects Collection at Logan, UT. Because DNA is known to degrade over time, it is necessary to first establish the reliability of this technique before implementation into larger studies. We tested three bumble bee species (Bombus huntii, Bombus occidentalis and Bombus appositus) to understand the applicability of our technique. Bombus occidentalis is a species of particular concern for conservation biologists as the species has disappeared from much of its former range. To test the technique with minimal damage to the museum specimen, one leg was removed from each of ninety-six individuals from each species. Sampled specimens ranged from 8 to 101 years old. The molecular markers worked successfully in specimens up to 101 years old, but the rate of success was significantly lower in material more than 60 years old. We correlated the age of specimens to failure of the technique and discuss potential impacts of using certain DNA markers for genetic studies of museum specimens.

Technical Abstract: Historic data in the form of pinned specimens in entomological collections offer the potential to determine trends in genetic diversity of bumble bees (Bombus). We screened eight microsatellite loci for amplification success in pinned bumble bee specimens from the U.S. National Pollinating Insects Collection. We tested three species (Bombus huntii, Bombus occidentalis and Bombus appositus) representing three subgenera of bumble bees (Pyrobombus, Bombus sensu stricto, and Subterraneobombus) respectively. Bombus occidentalis is a species of particular concern for conservation biologists. Single midlegs of ninety-six individuals from each species collected during the 20th century were assayed to determine microsatellite amplification success rates of historic material in a museum collection. Microsatellite alleles amplified in specimens up to 101 years old, but the rate of amplification success was significantly lower in material over 60 years old. Loci with shorter allele sizes amplified more frequently than relatively longer alleles in samples from all age classes. We correlated the age of specimens to the age at which loci fail to amplify and discuss potential impacts of using certain markers for population genetic studies of museum specimens.