The National Institute on Aging (NIA), part of the U.S. National Institutes of Health, revealed earlier this month that it will be phasing out its colony of calorie-restricted rodents. Although most researchers who study aging won’t be affected by the decision, some scientists will have to pay substantially more for experimental mice, and some may be priced out of the field.
In the 1930s, researchers first noticed that a very low-cal diet prolongs the life of some animals. This regimen, known as calorie restriction (CR), also delays age-related maladies such as cardiovascular disease and cancer. For nearly 20 years, NIA has sponsored a colony of calorie-restricted rodents, which are available only to its grantees. The price was right: Until this year, researchers paid $6 per month of the animal’s age plus shipping. And because of a rule change that went into effect in January 2014, the rodents are now free.
Despite the low prices, there isn’t much appetite for the CR mice. Just eight to 10 researchers request animals from the colony each year, says NIA’s Nancy Nadon, chief of the Biological Resources Branch. On 11 June, NIA announced it would not renew the contract with the company that houses the rodents, Charles River Laboratories in Wilmington, Massachusetts. “The way the usage has changed over the last few years,” Nadon says, “it wasn’t the best way to go about using NIA funds.” (She had no estimate of what maintaining the colony costs.)