Bumblebee (Hymenoptera: Apidae) sample storage for a posteriori molecular studies: Interactions between sample storage and DNA-extraction techniques

Abstract

Abstract.A global decline in pollinator abundance and diversity has demanded increased research attention to the ecology and genetics of bumblebees. However, as progressively more restrictions are placed on sampling for insects, researchers are increasingly obliged to use archival specimens collected for purposes other than genetic analyses. In this study we assessed the suitability, for population genetic studies, of popular, low-cost methods for preservation and storage of bumblebee specimens. Specimens of Bombus terrestris L. were held under six storage regimes for up to two years. DNA was extracted from the samples using three extraction protocols and the quality of the DNA was examined using PCR amplification of a mitochondrial and a nuclear gene. All extraction and storage methods provided sufficient DNA for successful PCR amplification. However, samples preserved in acetone or at freezing temperatures yielded the highest DNA concentrations. DNA yields from pinned specimens at room temperature declined over time, particularly when using standard extraction techniques. DNA concentrations were significantly lower from specimens preserved in 70% ethanol compared to all other extraction techniques and declined linearly over the two years of storage. These results indicate that two of the most popular insect storage methods (pinning and storage in ethanol) should be avoided for the long-term preservation of genetic material for future studies. We suggest that optimal insect preservation methods should be incorporated into research protocols in order to best capitalise on limited collection opportunities.

Influence of killing method on Lepidoptera DNA barcode recovery

“…; Moreira et al . ). The chemicals used during insect killing have also been mentioned as an important consideration in the literature (Dillan et al .…”

“…; Moreira et al . ), but few studies have focused on the effect of the killing method on DNA quality (Dillan et al . ).…”

Population genetic structure of Bombus terrestris in Europe: Isolation and genetic differentiation of Irish and British populations

“…Preservation techniques were adequate to maintain good quality DNA (Moreira et al . ). An additional population from New Zealand where B. t. audax was introduced from Britain in the 1800s (Howlett & Donovan ) was included in this study.…”

“…Samples were maintained in a 99% ethanol solution in the field, and all samples were later stored at À18°C in the laboratory. Preservation techniques were adequate to maintain good quality DNA (Moreira et al 2013). An additional population from New Zealand where B. t. audax was introduced from Britain in the 1800s (Howlett & Donovan 2010) was included in this study.…”

Solvent effects on binding energy, stability order and hydrogen bonding of guanine–cytosine base pair

“…For example methanol, ethanol, ether, acetone and chloroform usually are used for manual DNA extraction [12] to achieve a pristine DNA sample which is the goal of DNA extraction techniques. DMSO is also used for cell cryopreservation [13].…”