DNA test helps identify and protect North American wolves and coyotes
Forensic scientists can use a commercial test targeting mitochondrial DNA to accurately distinguish between wolf, coyote and dog species, according to a new study from North Carolina State University. Genetic information can be obtained from smaller or more degraded samples and could help authorities prosecute violations of hunting jurisdictions and preserve protected species.
In the United States, certain subspecies or species of wolves are endangered and restricted in terms of hunting status. It is also illegal to deliberately breed wolves or coyotes with domestic dogs.
“If it is a whole specimen, authorities can usually identify it based on physical characteristics, although the similarity between some species makes this method less than ideal,” says Kelly Meiklejohn, assistant professor of medicine. legal to NC State and corresponding author. of research. “If you are working with crossbreeds or incomplete specimens, you need DNA-based methods to accurately determine which species you have.”
Although some US federal laboratories perform DNA-based identification of wolves and coyotes, their methods and genetic reference databases are not publicly available. Meiklejohn has teamed up with the US Fish and Wildlife Service to see if it was possible to use a commercially available test designed for dogs as a means of retrieving the mitochondrial genome from various species of North American canids.
The mitochondrial genome is one of two genomes inherited from the parents of an animal. Specifically, the mitochondrial genome is inherited from the mother. It is useful for species identification both because its circular shape makes it less prone to degradation and because there are more copies of this genome per cell, increasing the chances of recovering useful material from it. small or damaged samples.
The team used a method, called “capture by hybridization,” in which about 80 base pair long RNA fragments are used to isolate DNA for sequencing. The samples are incubated with the RNA fragments, and if there is a match, the fragment will bind to the sample DNA. Linked DNA can be isolated and sequenced. In this case, the team used a hybridization capture panel designed for the dog’s mitochondrial genome.
“The fragments will bind together if there is about 80% similarity, which is why we thought the dog kit would be useful for sequencing wolves and coyotes,” Meiklejohn explains. “Dogs only diverged from wolves about 20,000 years ago, so the mitochondrial genomes aren’t that different.”
They sequenced 51 samples and were able to recover complete mitochondrial genomes and successfully differentiate four species of interest: the dog, the wolf, the Mexican wolf and the coyote.
“Essentially, this discovery means we can do more with less,” Meiklejohn says. “In forensics, we rarely have high quality DNA samples; they have usually been exposed to the environment and are degraded. The flexibility of this kit allows us to determine which species we are examining, which can round helping to continue hunting or breeding violations and protecting endangered canine species. “
Source of the story: