Big Things to Come in Bison Research

Thursday, October 26, 2023

Usask's project works to develop new tools and healthy genetics.

By Emily Croft

A team at the University of Saskatchewan and Parks Canada are working to create sustainable tools to help bison return to the Canadian Prairies.

The Bison Integrated Genomics (BIG) Project is a collaborative effort between several organizations and is led by Dr. Gregg Adams, a professor in the Department of Veterinary Biomedical Sciences at USask, and Dr. Todd Shury, the manager of the Wildlife Health and Management team at Parks Canada.

The overall goal of the project is to develop tools to support healthy genetics and reduce disease risk in wood and plains bison.

After many repeated threats to the species, in the 1920s plains bison were driven north and co-mingled with wood bison. Wood bison were exposed to cattle diseases that were picked up by the plains bison in the south, and hybridization between the plains and wood bison resulted in reductions in genetic fidelity and healthy diversity among remaining populations.

Adams describes it as "a perfect storm that caused near extinction and has left us with a real quagmire."

Modern conservation efforts have been difficult due to genetic intermingling and the diseases still carried by the bison.

"We haven't progressed as well as we could and this project is how can we make the conservation effort move along," says Adams.

A large part of the problem is the risk of transferring disease back to cattle populations.

"Bison are one of last reservoirs of bovine tuberculosis and brucellosis in Canada," says Shury.

"There has been an eradication program for 100 years. Luckily the diseases haven't spilled over from bison in national parks, largely due to remoteness, but it could happen eventually, and we want to make sure we have tools in place to avoid it."

Shury explains that this project has been in the works for a while now.

"The project really started out quite a few years ago – around 12 years. The collaboration started as a hallway conversation and then we started looking at different possibilities to carry it out," says Shury.

"Gregg was interested in starting reproduction research in bison and there had been very little work done in the past.

"We had surplus of bison from Elk Island National Park and created a herd at the university to start very basic reproduction research in females and then started doing basic work on the male side as well."

After working with Genome Canada to apply for funding through the Genomic Applications Partnership Program (GAPP), the BIG project was created.

To address the challenges in bison conservation, the BIG project is broken down into four main activities:

• Develop more sensitive and specific diagnostic tests for disease in bison.
• Develop a combined brucellosis and tuberculosis vaccine for wood bison.
• Create genomic tools for assessing the genetic composition of bison herds.
• Collect and transfer healthy genetics between existing bison herds.

As part of developing genomic tools, it's necessary for the team to assess what the genetics of bison looked like before they were mixed.

"One of the most exciting parts for me is being able to go back in time to determine what the gold standard was for unadulterated plains and wood bison, and until now we haven't had a tool to do that," says Adams.

"One of the goals is to determine if we have any pure wood bison left in the world. Present day bison may well all be mixed."

To discover if there are any pure wood bison, the team must look back at the genome of the bison before they were mixed.

"One tool is a SNP test that can identify whether it's a plains bison or wood bison. They are similar, so it can be hard to distinguish, and genetics have mixed, so that's a big part of project," says Shury.

Adams explains that "one of the steps is going back to samples that are 200 to 2,000 years old and looking at the genetics.

"Then we can say for sure that we do have plains bison or wood bison, with or without mixing between species or with cattle. Now we have the tools to answer that question."

The team also aims to develop a bison genome biobank, to allow for the collection and transfer of healthy bison genetics.

"This has already started, and we have genetics in the biobank.

"There will be a process of putting together germplasm inventory, and that's happening now. And we have developed a system to handle all the genetic data to go along with it," says Adams.

"We are developing tools to be able to do this in wild, free-roaming animals. You dart them and collect semen or eggs in recumbent animals, which isn't always easy.

"We are right at the cusp of seeing the biobank take off with enthusiasm and support from local communities – a lot of which are Indigenous communities."

Shury says that tools that allow genetics to be moved without moving live animals will help prevent the spread of disease.

"When we move live animals, we tend to move diseases as well and it can be difficult to detect."

"If you are only moving semen or embryos there's a reduced risk of transferring disease and it's far cheaper to move around – moving frozen straws of semen or embryos is a fraction of the cost of moving the whole animal."

Only one year into the three-year project, the team has already made progress toward their goals.

"We've made a lot of progress on Activity 3 (developing tools to assess genetic composition in herds) and have made progress on the vaccine front, but we likely won't have a lot of these tools until the third year of the project," says Shury.

"I think our biggest challenge so far has been translating some of these advanced reproduction techniques to local communities and explaining the long-term benefits of how this project will help these herds."

Adams adds, "Some people don't feel comfortable with assisted reproductive technologies. I think that's changing now and I think in this last year we've seen real progress and support of this effort.

"I'm optimistic we will have a busy couple of years. I think the impact will last a very long time."

A few other studies have already proven the benefits of reintroducing bison to Prairie ecosystems.

"Bison are really one of these species that are considered a keystone of different ecosystems," says Shury.

"Where they've been reintroduced, they find there's greater biodiversity. They create wallows that are habitats for other animals, birds use bison hair for nests, and there are lots of studies about reintroduction that show the benefits to the ecosystem.

"When they are reintroduced, we want those bison to be as healthy as possible."

Through genetics and disease prevention, Shury hopes that bison can return to northern Canada.

"If successful, there will be swaths of northern Alberta and Northwest Territories with populations of healthy bison. Indigenous communities that hunt bison also won't have to worry about infection from these diseases anymore, as they are zoonotic," says Shury.

Although Shury and Adams are leading the team, a number of organizations, stakeholders, and researchers are involved in making the research a success and sharing these successes with impacted communities, including the Toronto Zoo, the Canadian Bison Association, and other universities.

"It's probably one of the few projects where we are trying to build from the ground up with a lot of community engagement, which is difficult to do.

A lot of other research is done in the lab without a lot of the input from community, and it can be difficult to match the needs of science to the needs of the community," says Shury.

Adams adds that "one of the most gratifying parts of this project is to have a diverse group of scientists and participants all facing in the same direction. It's amazing to work with a team like that." BF