The wolverine, a recluse, becomes more of an open book to scientists

A wolverine caught near Kugluktuk more than 30 years ago is central to a breakthrough that will help conservation of an animal that’s ordinarily hard to study.

Scientists have used frozen kidney tissue from that wolverine, preserved since 1990 at the Royal Ontario Museum, to sequence the whole genome of a North American wolverine for the first time.

Whole genome sequencing means developing a complete list of the genetic information that makes a wolverine what it is.

Researchers say they can now use a map of thousands of genetic markers to reach conclusions about animals in the wild far more quickly than in the past.

“You get tons of information from sequencing a wolverine,” said Dr Matthew Scrafford, a Wildlife Conservation Society Canada scientist who contributed to the paper that announced the completed genome assembly.

Dr Scrafford specializes in wolverine conservation. He says a process called resequencing will now allow researchers to extract far more information than was previously the case from small traces they find in the wilderness, such as samples of hair or scat.

To Scrafford, that’s important because wolverines are difficult to study: there aren’t many of them, their habitat is a vast stretch of northern Canada, and they are reclusive, normally found travelling alone for distances of 20 km or more in a day.

“I’ve done two GPS collaring projects on wolverines – one in northwestern Alberta and one in Ontario – for about 11 years now,” Scrafford told Cabin Radio.

“You’ve got to work really hard to get any sort of data, and that’s one of the reasons wolverines are considered a species that is data-deficient in a lot of places.

“That’s why getting this genome assembled is such a big deal. It will allow us to learn a little bit more about them, particularly through collecting things like scat.”

Lynx and snowshoe hare coming up

The wolverine is not considered a species at risk in the Northwest Territories but, more broadly, wolverine numbers are thought to be in decline.

In the North, their habitat is threatened by a rapidly changing climate and human interference from the likes of mines, forestry and highways.

Scrafford says having the wolverine genome to hand will make it easier to study how the animals are adapting to those changes.

“By assembling the genome, you get a much larger number of markers that allow you to look at the genetic differentiation among populations in a more detailed way,” he said.

As examples, Scrafford said, a better understanding of the wolverine’s genome assembly will help to assess how wolverines are adapting to changes in the availability of snow and variation in their habitat.

“It allows you to identify individuals that might have an enhanced ability to adapt to a changing environment,” he said.

“Climate change has the potential to have a huge effect on wolverines. They are a cold-adapted northern species and climate change is turning that on its head. You’re getting a warmer environment, you’re getting less snow. Physiologically, you’re stressing wolverines. Behaviourally, you’re affecting their environment.

“Wolverines like to cache. They scavenge, then they cache food in permafrost or in snow and rocks, partly because it won’t spoil until they come back. Well, climate change will have an effect on that, and that’s a big behavioural adaption.”

Si Lok, the paper’s lead author, told the Genetics Society of America the team is now working on the genome of other species that may be threatened by shifts in northern climate, such as the lynx and snowshoe hare.

In the wolverine’s case, the genome breakthrough will also allow researchers to more readily trace a given animal’s family tree, which may in turn mean a better understanding of the consequences of inbreeding or the spread of offspring.

“It is a powerful thing, in the sense that we can now get so much more information from simple, non-invasive biological samples,” said Scrafford.

“We can look at inbreeding, genetic connectivity, how different individual populations are connected, and how human disturbance affects that.

“There are lots of different questions we can ask, because we now have the ability.”