Data from: Improving PCR detection of prey in molecular diet studies: importance of group-specific primer set selection and extraction protocol performances
While morphological identification of prey remains in feces of predators is the method most commonly used to study trophic interactions, many studies indicate that this method does not detect all consumed prey. Polymerase Chain Reaction based methods are increasingly used to detect prey DNA in the p...
| Main Authors: | , , |
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| Format: | Article in Journal/Newspaper |
| Language: | unknown |
| Published: |
2012
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| Subjects: | |
| Online Access: | http://hdl.handle.net/10255/dryad.42331 https://doi.org/10.5061/dryad.8c134 |
| Summary: | While morphological identification of prey remains in feces of predators is the method most commonly used to study trophic interactions, many studies indicate that this method does not detect all consumed prey. Polymerase Chain Reaction based methods are increasingly used to detect prey DNA in the predator food bolus and have proved themselves efficient, with high accuracy. When studying complex diet samples, the extraction of total DNA is a critical step, as PCR inhibitors may be co-extracted. Another critical step consist in carefully select suitable group-specific primer sets that should only amplify prey DNA from the targeted taxon. In this study, the food boluses of five Rattus rattus and seven Rattus exulans were analyzed using both morphological and molecular methods. We tested a panel of 30 PCR specific primer sets targeting Bird, Invertebrate and Plant sequences and four were finally selected to be use as group-specific primer pairs in PCR protocols. The performances of four DNA extraction protocols (QIAamp DNA stool mini kit, DNeasy mericon food kit and two CTAB-based methods) were compared using four variables: DNA concentration, A260/A280 absorbance ratio, food compartment analyzed (stomach or fecal contents), total number of prey specific PCR amplification per sample. Our results clearly indicate that the A260/A280 absorbance ratio, which varies between extraction protocols, is positively correlated to the number of PCR amplifications of each prey taxon. We recommend using the DNeasy mericon food kit (Qiagen), which yielded results very similar to those achieved with the morphological approach. |
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