Genomic Tool Developed to Identify Cryptic Whitefish Species in Great Lakes
Researchers developed a genotyping panel of 494 loci capable of distinguishing members of the Coregonus artedi fish complex in the Laurentian Great Lakes, species that cannot be told apart using standard DNA barcoding. The panel was successfully used to identify over 3,000 coregonine larvae and juveniles collected from Lake Superior between 2019 and 2021. The findings advance conservation efforts for these salmonids and suggest that GT-seq panels can be repurposed across related taxa, broadening their utility in fisheries management.
A team of researchers has developed a GT-seq (Genotyping-in-Thousands by Sequencing) panel targeting 494 genomic loci to differentiate species within the Coregonus artedi complex, a group of salmonid fishes in the Laurentian Great Lakes that are morphologically cryptic and indistinguishable using mitochondrial DNA barcoding. The panel was able to assign individual fish to both species and lake of origin, addressing a critical gap in early-life ecology research where egg and larval stages are particularly difficult to identify. The study also tested cross-amplification in related species, finding that Lake Whitefish (C. clupeaformis) amplified at 94% of loci, while Round and Pygmy Whitefish (Prosopium spp.) amplified at 42% and 38%, respectively. To accommodate these related species, the researchers adapted bioinformatic probes to include 22 new SNPs and created a whitelist of 428 SNPs capable of distinguishing all whitefishes in the region. The panel was validated by successfully identifying 3,066 larval and juvenile coregonines from Lake Superior, demonstrating both its practical utility and the broader potential for off-target use of GT-seq panels in conservation genomics.
What's missing
The study does not report formal accuracy or error rates (e.g., misassignment rates) for species identification, nor does it address how panel performance might vary across different collection years, locations within Lake Superior, or sample preservation methods. Long-term validation across additional lakes in the Great Lakes system is also not yet demonstrated.
What different sources said
- bioRxivCenter
A genomic tool to tackle cryptic diversity demonstrates the potential for off-target use of GT-seq panels
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