Progress in the Quest for More Effective Control of Gopher Populations

Source: Saskatchewan Agriculture and Food

Gophers present a significant problem to agriculture in Saskatchewan and in other North American jurisdictions. Wherever they live, gophers tend to create problems, says Andrew Olkowski, a researcher at the University of Saskatchewan who has been looking for solutions to the gopher problem.

“We proposed to undertake a research project inspired by information that I read in the press several years ago," he says. "People were complaining that the gopher population was growing. I read comments to the effect that poison is not working, or is difficult to get."

As a toxicological researcher, this was a challenge Olkowski could not resist. He and his research team decided to investigate the problem. Why is the gopher population growing despite the efforts to control it?

Saskatchewan Agriculture and Food’s (SAF) Agriculture Development Fund helped finance the project (ADF #20020076). Olkowski assigned his team to some basic investigative work.

“When any toxin enters the body, the gopher's first line of defence is to get rid of the toxin as fast as possible. This happens when the toxin is being metabolized. How fast it is metabolized? That is what pre-determines the effectiveness of the toxin. So essentially, if the toxins that are currently being used on gophers are less effective in some cases, there must be some biological explanation."

Olkowski’s project was designed to test all the major pathways that are responsible for breaking down toxic compounds.

"We captured a number of gophers for the study and harvested the liver tissue, then extracted the enzymes that are responsible for detoxification. This gave us a very good idea of how, at what speed, and at what rate those compounds are metabolized. We essentially learned which ones are the compounds that metabolize faster and which are slower; what the gender differences are, and quite a few other things.”

Part of this study also compared two different groups in an attempt to determine why the toxins do not work in some situations.

“We wanted to test a group of gophers that were not exposed to toxins in the past, and compare them to another group that was captured from a field where attempts to control them for a number of years had been made. Essentially, one group had been exposed to toxins and the other had not.

“What we found out was quite intriguing. It turned out that animals that were captured from the field, the ones that had been previously exposed, had actually built up quite a bit of resistance—the metabolic pathways in this group of animals were much better equipped to deal with the toxins. They acquired a certain immunity to them.”

Olkowski admits that this in itself is not something new, but it is revealing.

“You can actually stimulate a lot of these metabolic pathways in an artificial way. In experiments done on rats, the subjects were given low doses of a drug designed to make them sleep. They acquired such immunity to this drug that other rats that hadn't been exposed to the drug fell asleep rapidly, while the exposed rats were not even losing consciousness. Even humans develop mechanisms to deal with sleeping pills. If used for a long period of time, they become ineffective. It is the same type of mechanism.

"We tested generic pathways that are organised in certain patterns of metabolisms, so some groups can be added to the original chemical to basically facilitate excretion of this chemical. This is a kind of reaction that we call a biotransformation. Usually the aim of this organism is to make the compound less available to the body and more excretable, therefore less toxic.” Usually, this would happen because the metabolism would add some function to make it more soluble, more excretable, or it would immobilize some toxic paths of the chemical, explains Olkowski.

“We didn’t come up with miracle solutions, but on the basis of this study, we now have enough information to think about designing a new generation of drugs. We know which structures are metabolized faster, and what the gender differences are. We found quite a significant difference between males and females. This can be used as a target.”

For more information, contact:

Andrew Olkowski
Researcher
Department of Animal and Poultry Science
University of Saskatchewan
(306) 966-5848