Geology topics

Cameron M. Layne

Publications and source records attributed to Cameron M. Layne.

2 recordsLinked to original sources

USGS2025

Quantitative PCR detection of endangered diamond darter Crystallaria Cincotta in environmental DNA: Employing locked nucleic acids and blocking probe for specificity

This study presents a quantitative PCR (qPCR) assay for the detection of the endangered diamond darter Crystallaria cincotta from environmental DNA (eDNA) in water samples. The assay design is based on an alignment of mitochondrial cytochrome b DNA sequences from 58 individuals representing 25 percid species. Leveraging genetic differences, a species-specific qPCR assay was designed, incorporating alocked nucleic acid (LNA)-enriched probe and a secondary blocking probe to enhance specificity. The assay targets a 93-base pair fragment that includes a diagnostic single nucleotide polymorphism in the probe region; combined with multiple primer mismatches, this provides specificity for distinguishing C. cincotta from other sympatric percid species. Specificity was validated by testing genomic DNA from 16 percid species and synthetic templates, confirming no cross-reactivity. Performance metrics, including the standard curve, qPCR efficiency, limit of detection, and limit of quantification, are reported. The qPCR assay exhibited sufficient sensitivity to detect C. cincotta eDNA in environmental water samples collected from occupied riverine habitats. This study illustrates the effectiveness of LNA-enriched and blocking probes in developing species-specific qPCR assays for eDNA applications, demonstrating their utility in accurately distinguishing closely related species within diverse fish communities.

Conservation Genetics Resources↗

USGS2024

Paddlefish movement and dam passage in the Ohio and Kanawha Rivers, West Virginia

The Paddlefish ( Polyodon spathula ), a large-bodied and highly migratory species of large river systems, has experienced population declines or extirpation in parts of its native range. As an effort to reestablish a Paddlefish population in the Ohio River of West Virginia, the West Virginia Division of Natural Resources has stocked fingerling Paddlefish in the previous two decades. Post-stocking studies could assess the status of the reintroduced population, which includes collecting information on their seasonal movements and dam passage frequency through navigation dams of the Ohio and Kanawha Rivers. Using acoustic telemetry techniques, we monitored seasonal movements and assessed dam passage of five Paddlefish in the Robert C. Byrd Pool of the Ohio and Kanawha rivers. Paddlefish were highly mobile with two individuals using the entire R.C. Byrd Pool during the 11-month study period. Most movements occurred during the expected spawning period of April and May, where all individuals frequented the upper section of the pool in the Kanawha River. Downstream passage was documented for one individual at the R.C. Byrd lock during July 2023, but no evidence of upstream passage was documented for the locks at Racine (Ohio River) or Winfield (Kanawha River). Tagging of additional Paddlefish would be beneficial to increase sample size for future assessments and continue efforts toward the long-term conservation and management of Ohio River Paddlefish.

West Virginia↗