Express for Success: Science Targets Gene Expression by: Geoff Geddes


Though encouraging kids to express themselves sounds like a good idea, it’s often better in theory than in practice. By contrast, gene expression and genetic factors that contribute to traits of interest are integral to success for researchers on the Efficient Dairy Genome Project.

“As part of this project, we are trying to identify the functional SNPs [the most common type of genetic variation]that affect feed efficiency and methane emissions,” said Dr. Angela Cánovas, Associate Professor – Department of Animal Biosciences at the University of Guelph. “To do so, we go beyond the DNA level to measure the expression of all genes in the transcriptome of the animal. We are combining the genome sequence – or DNA information – with the gene expression – or RNA sequence – to obtain the best possible results.”

Through this work, researchers hope to pinpoint what separates animals that are more efficient in regard to feed or methane emissions, from those that are less efficient. Do the better performing cows have a certain gene expression profile, microbiome profile or functional markers that make them superior?

Getting selective

“We need to validate these potential functional markers in independent cattle populations and see if we can include them in breeding programs to select for feed efficiency and methane emissions,” said Dr. Cánovas. “We are also in the process of identifying if there is a specific microbiome profile associated with these two traits. This is an interesting aspect, as the microbiome profile appears to be different for each cattle breed analyzed, and this is invaluable information when it comes to breeding and selection.”

Another key aspect of this research for Dr. Cánovas and her team is studying the bacteria present in the rumen fluid of cattle. Rumen fluid is the mixture of all fluids present in the rumen chamber as a consequence of digestive processes and ingestion.

“We know that within the rumen fluid, bacteria play an important role in the absorption of nutrients. Our understanding of these bacteria, and the interactions between the host and the microbiome profile associated with feed efficiency and methane emissions, could allow us to better select for more efficient animals.”

Among the benefits of this research to industry, that ability to enhance selection is perhaps the most impactful.

“If we can identify functional SNPs, we can improve the accuracy of selection and introduce those SNPs into breeding programs. As well, we can achieve a two-pronged gain for producers by selecting cows that have both specific genetic attributes and a specific microbiome profile related to feed efficiency or methane emission. By doing so, we produce animals that are genetically superior in terms of efficiency, while also having sustainable cattle, thereby maximizing performance.”

From both a scientific and practical standpoint, this research offers a lot for scientists to get excited about.

Science meets sustainability

“For me, the project is a chance to explore genetics at a deeper level and better understand the interaction between the host and the microbiome. It’s a novel relationship, and we don’t know which one of the two is a cause, and which is a consequence, so this work will help clarify the dynamics, and that’s very exciting from a scientific standpoint. In terms of real world applications, it’s gratifying to be identifying genetic markers that we can actually incorporate in breeding programs and boost the producer’s bottom line while making the industry more environmentally friendly.”

Based on interest from the scientific community, Dr. Cánovas is not the only one enthused about the project. She was invited to present her latest results at several national and international conferences, including the recent 37th International Society of Animal Genetics (ISAG) Conference in Spain.

Though “expressing yourself” is important for kids, gene expression is probably more productive and, ultimately, far less destructive.