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Singh a master of adjusting research focus

Dr. Jaswant Singh has mastered the ability to adjust his research focus — much like a camera lens. From one day to the next, the reproduction specialist's mind goes from taking a wide-angle, whole-animal view of a cow's reproductive system to zooming in on the bovine oocyte (immature egg).

That's partly because of his multi-layered research. Using cows as models, Singh and his graduate students are helping to improve cattle breeding and learning about bovine reproductive physiology. They're also helping researchers learn more about human reproduction.

"My research spans from studying the individual enzymes at the oocyte level to applying what we've learned about cattle reproduction to the whole animal level," explains Singh, whose chief interest is the oocyte's structure. "I've always been interested in connecting the function with structure and understanding how the two are correlated."

Singh joined the Western College of Veterinary Medicine in 2000, returning three years after finishing his PhD at the veterinary college. A Commonwealth scholarship recipient, Singh left his faculty position at the Punjab Agricultural University of India and came to the University of Saskatchewan in 1993 where he joined Dr. Gregg Adams at the WCVM.

As Adams' first graduate student, Singh was involved in the young scientist's work on ovarian follicle development with Dr. Roger Pierson at the U of S College of Medicine. He also became part of the university's Reproductive Science and Medicine Research Group that strongly encouraged collaborations between human and veterinary researchers.

"That environment was very conducive for research — and I still think that's the case," says Singh.

During this time, Adams, Pierson and Singh realized the potential of using cows as a research model. Many attributes of bovine ovarian follicle development are similar to those in humans, plus in vitro culture conditions for oocytes and embryos were already established in cattle.

"Then came the idea of using old cows as a model to mimic events that happen during a woman's perimenopausal period," recalls Singh. 

 He estimates that a 12-year-old cow is similar to a 35-year-old woman — the age when many women with careers want to begin having children. But between 35 and 40, there's a rapid decrease in women's ability to conceive and greater potential for fetal abnormalities.

"Using the older bovine model, we can try to understand what triggers different events in the oocyte and what affects its quality in both species," says Singh.

Based on a series of studies over the past six years, Singh and his graduate students proved the value of using older cows to learn about human reproduction. Their investigations showed that women after 35 years old and cows in their early teens share similarities in follicular development, reproductive hormone levels, embryo development and oocyte quality.

All of these investigations involved cows that are part of the WCVM Goodale Research Farm's herd. Singh selected older, successful breeding cows and identified their younger daughters so comparisons could be made between younger and older females with genetic similarities.

Now Singh and his team are taking an in-depth look at oocytes. They're investigating the theory of whether mitochondria (the cell's principal energy source) become less active in older oocytes and less protective of the unfertilized eggs.

Singh and PhD student Dinesh Dadarwal are studying mitochondria using a new confocal microscope that was purchased by the College in partnership with Agriculture and Agri-Food Canada. "We're looking at the mitochondria's structure, their numbers in old cows versus young cows, and whether mitochondrial function changes over time," explains Singh.

Another PhD student, Dr. Muhammad Irfan Khan, is studying gene expression in the follicles of old cows versus young cows. The exploratory project will compare genes from both groups and target any of the genetic differences for further research. These investigations, which are part of the EmbryoGENE research consortium funded by the Natural Sciences and Engineering Research Council of Canada (NSERC), are in partnership with the Université de Laval and the University of Alberta. 

"For us, the oocyte is the whole universe, so sometimes we forget to stand back and look at the big picture," explains Singh. "That's what we're trying to do with this genetic research: we're exploring 40,000 genes rather than one gene at time."

On the other hand, Singh's group is capturing some of the first closeup images of oocytes with a powerful ultrasound biomicroscope that allows them to view oocytes that are 0.1 millimetre in size. "Last summer, we recorded images of oocytes within the cow within a follicle," says Singh. "This opens a new avenue for us where we can compare the image attributes of good versus bad oocytes."  

To complement the maternal aging research, Singh and Dr. Fernanda Dias, one of his PhD students, are conducting research to determine the effects of follicular aging on cows' follicles. She's studying how the genes of follicle-stimulating hormone (FSH)-starved and FSH-supported, super-stimulated follicles differ from those naturally developed by cows. 

"Again, that has applied implications for breeding and for producing embryos," points out Singh. "If we understand what goes wrong, then hopefully we can go back, correct the problem and come up with protocols that will give us good oocytes."

While NSERC funding has allowed Singh to conduct fundamental studies in bovine reproduction, six years of grants from the Saskatchewan Agriculture Development Fund have enabled him to conduct investigations with practical applications for the cattle industry.

For example, Singh's team proved that low progesterone levels aren't detrimental for developing oocytes — a misconception believed by many cattle breeders. They showed that low progesterone levels given for short time periods actually give better oocytes than those developed with high progesterone levels.

Singh has also collaborated with WCVM theriogenologist Dr. Reuben Mapletoft to develop fixed-time artificial insemination protocols that are now used by cattle breeders in South America and other parts of the world.

More research opportunities arise as people's perceptions change along with society's needs. For instance, after countries banned the use of estradiol (estrogenic hormone used to synchronize animals' follicle waves) in food-producing animals, the need arose for an alternative treatment. Now, that's another new challenge for Singh and his research group — something he continues to relish. The novelty of being one of the many individuals who contributes small bits of information to a greater ocean of knowledge has never grown old for Singh.

"Every day I go home and I ask myself, ‘What new thing did I do today that I haven't done previously?' That's something that still gives me a whole lot of satisfaction."

Originally published in the 2009 WCVM Research Report.

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