Retirement moms

Retirement moms

A Nova Scotia researcher has discovered a gene that may allow women to have babies well into old age
October 1, 2003

Dr. Hossain Farid has a radical vision for the reproductive future of humans. Forget about having kids in your 20s or 30s. Within several generations, he says, our baby-making years will mesh with our retirement years. That means women in their 60s and 70s will be buying maternity clothes and planning baby showers.

"We'll have two separate lives. You'll go to school and work, retire at 55, and then have children," says Dr. Hossain Farid, a Professor of Animal Breeding and Genetics in the Department of Plant and Animal Sciences at Truro's Nova Scotia Agricultural College (NSAC).

Farid's revolutionary image of the future is based on present-day facts. He recently identified the first gene in mice that plays a role in , the age to which females can have babies. The gene has already been shown to have the same effect in pigs, and might well be common to all mammals—including humans. "If it's possible to find out how this gene works, you can produce some kind of medication so that women can produce healthy kids at the age of 65, which isn't really old if life expectancy exceeds 120 years," he says.

The gene's discovery, with the help of CFI-supported equipment, was made using a unique colony of mice that have been bred for the past 22 years for their ability to have babies into old age. The mouse colony, of about 1,000 pairs, is made up of two groups: one group has been bred to reproduce into old age; the other "control group" acts as a normal point of comparison.

While mouse moms in the control groups have litters for an average of about 173 days, the "superbreeders" are able to push out pups over a whopping average of 321 days. This means the superbreeder moms have double the number of litters during their lives as compared with the control group moms.

Farid hit the genetic jackpot in early 2002, when he identified a region of a gene known as a DNA marker, that was different in the control group and the superbreeders. He discovered the gene linked to reproductive longevity by comparing several genes between the selected mice and those in the control groups using an automated DNA sequencer. "We don't exactly know the gene's role," says Farid. "All we know is that all those individuals that reproduce longer have this gene with a particular marker in it."

The results have not yet been publicly announced as Farid and Performance Genomics Incorporated, the company sponsoring the research, wait for a patent on the gene. Given this initial success, Farid is now broadening his search and using his lab's DNA analysis power to search the entire mouse genome, an estimated 35,000 genes, for those genes that control reproductive longevity.


Livestock breeders are always looking for ways to improve their herds. As a result, the ability to identify and potentially regulate the genes that control how long an animal has babies will have its most immediate impact in the livestock industry. Farid and his colleagues in the Department of Plant and Animal Sciences at the Nova Scotia Agricultural College are focusing on agricultural genomics, the use of genetic information to help farmers improve their livestock and crops. Increasing the length of time a cow or sow reproduces, and thus the number of her offspring, would be a major financial boost for farmers.

Some characteristics, skin colour for example, are relatively easy to choose and change — a farmer simply looks at a cow and a bull to reliably judge the resulting calf's colour. However, for complex traits, the most useful clues to a calf or piglet's characteristics are below the skin surface—in the genes. "Some traits are very difficult to improve, like reproductive longevity, or how long a cow will be able to reproduce," says Farid. "You have to wait about 15 years for a cow to stop reproducing, and with research you can't wait that long." That's why, he says, genetic techniques are becoming more and more important in animal and plant breeding.

Farid's speciality is locating DNA markers, bits of DNA that act as signposts pointing scientists to genes that influence particular traits such as disease resistance or how long an animal will reproduce. While the initial goal is helping farmers increase the number of calves and piglets they can raise from a single mother, Farid believes the genetic detective work he's doing today could one day have senior citizens having baby showers.


In early 1998, Farid received an intriguing offer. A colleague at Agriculture and AgriFood Canada in Ottawa called to say that the federal agency was closing much of its livestock research division. As a result, a unique colony of mice bred for reproductive longevity would be dispersed. Farid recognized the golden opportunity and wasted no time speaking with Nova Scotia Agricultural College's Vice-president at the time, Dr. Ted Burnside, and the head of his department, Dr. Don Crober. The College agreed to buy the rodent colony for a loonie. It has turned out to be a great investment. "We are now the only institution in the world that has a line of mice selected for reproductive longevity," says Farid.

To capitalize on the commercial value of any genes discovered in the colony of mice, the College created Performance Genomics Incorporated (PGI), its only biotech spin-off company to date. The College is currently PGI's majority shareholder, with an additional investment from PIC, a global market leader for improved pig breeding stock. PGI foots the $120,000-a-year bill to keep the 2,000 members of the mouse colony housed, fed, and cared for. Based on Farid's recent discovery of the world's first mammal gene related to reproductive longevity, PGI expects to have its first gene patent in the fall of 2003.

Farid says the Canada Foundation for Innovation was an essential part of making PGI possible because it provided the funding for a variety of genetic research tools, including an automated DNA sequencer. "We had the mice and the CFI provided us with the badly needed research infrastructure," he says.