CVM Conservation Geneticists Identify Reliable Genetic Markers in Bison Feces
Researchers at the Texas A&M College of Veterinary Medicine and Biomedical Sciences (CVM) have identified a series of genetic markers found in bison fecal samples that can be used to identify bison population trends.
Published in the most recent issue of the journal BMC Genetics, the article reevaluates the belief that DNA obtained from American bison chips is not a valid source of DNA for conducting research.
“Our research involves American bison conservation genetics and we are working to develop a panel of genetic markers that can be used to identify bison population trends,” said James Derr, a professor in the CVM’s Department of Veterinary Pathobiology (VTPB) who led the study.
Working in close collaboration with biologist from Yellowstone National Park, the CVM team acquired both fecal and blood samples for DNA analysis from 50 bison.
While, it is well known in the scientific literature that DNA from fecal samples is often unreliable due to its low quality, few wildlife studies have directly compared fecal DNAs to high-quality DNAs such as those obtained from blood to aid in marker selection.
“Some genetic markers (in our study) produced major discrepancies between the fecal and blood samples from the same bison,” said David Forgacs, graduate student and first author of this publication.
However, after analyzing the results from 35 genetic markers, the team identified 15 of these markers that perform very reliably with bison fecal samples and can be used for random and non-invasive population sampling.
Therefore, the researchers concluded that since most wildlife studies using fecal samples do not use paired samples during marker selection, they may have significantly skewed their data.
This finding has far-reaching consequences, as many genetic studies have used DNA from fecal samples with wildlife species that are difficult or dangerous to capture.
In addition, DNA derived from fecal samples is consider a non-invasive and safer alternative sampling strategy for rare and endangered species.
Nevertheless, “conservation biologists and wildlife enthusiasts may have a reason to rejoice because, according to our findings, many studies that have used fecal samples in the past may have underestimated the genetic diversity and overestimated the negative effects of inbreeding in many wild populations,” Forgacs said.
The article— “Evaluation of fecal samples as a valid source of DNA by comparing paired blood and fecal samples from American bison (Bison bison)”— is available at https://doi.org/10.1186/s12863-019-0722-3.
