Development and validation of rapid environmental DNA (eDNA) detection methods for bog turtle (Glyptemys...

Area of Science:

• Conservation Biology
• Molecular Ecology
• Environmental DNA (eDNA) Analysis

Background:

• Bog turtles (Glyptemys muhlenbergii) are a Species of Greatest Conservation Need (SGCN), requiring effective population assessment methods.
• Traditional sampling is hindered by wetland habitats, small size, and burrowing behavior, necessitating non-invasive molecular techniques.
• Developing species-specific qPCR assays is challenging due to high genetic similarity with cohabiting species and environmental inhibitors in eDNA samples.

Purpose of the Study:

• To develop and validate a highly specific qPCR assay for detecting bog turtle eDNA.
• To create a full-process internal control to improve DNA extraction efficiency and mitigate qPCR inhibition.
• To assess the impact of DNA recovery variability on eDNA-based detection rates.

Main Methods:

• Developed the BT3 qPCR assay targeting the mitochondrial cytochrome oxidase I gene.
• Validated the assay using 201 blood samples from six species across a wide geographic range.
• Incorporated a genetically modified Caenorhabditis elegans strain as an internal control for DNA extraction and qPCR inhibition.

Main Results:

• The BT3 assay demonstrated 100% specificity and sensitivity in identifying bog turtles.
• The internal control revealed significant variation (over an order of magnitude) in DNA recovery between samples.
• Variable DNA recovery was identified as a key factor limiting bog turtle detection in eDNA studies.

Conclusions:

• The BT3 assay provides a specific and sensitive tool for bog turtle eDNA detection.
• The developed internal control enhances the reliability of eDNA analysis by accounting for DNA recovery and inhibition.
• These methods offer a cost-effective, non-invasive approach to supplement bog turtle population monitoring in the Eastern United States.