Genetic Networks Research Progress

Massive genome sequencing projects have already generated catalogues of all the genes for a variety of organisms, including humans. But with billions of base pairs to comb through and analyze in each catalogue, researchers face great challenges in interpreting this data. The Genetic Networks program approaches this challenge by mapping and comparing how sets of genes work together, one organism at a time.

Since the inaugural meeting of the program in 2006, members made major progress in mapping genetic interactions. Partial network maps now exist for several model organisms, including two different yeast species, and the nematode worm.

Using a budding yeast map, which clusters genes according to the key roles they play in survival of this organism, CIFAR researchers discovered that only 19% of yeast genes are absolutely essential to keep the cell alive. Many of the remaining “non-essential” genes share complementary roles, such that if one gene is damaged or destroyed, another can compensate.

Program members also tested whether genetic interactions are conserved between species – a key question to applying their knowledge of model systems to more complex organisms, including humans. They compared two types of yeast that are distantly related and separated by a billion years of evolution. These yeasts share three-quarters of their genes and as much as one third of their genetic interactions. This finding suggests there might be a core genetic network common to many even more distant species.

New genetic interaction maps and conservation studies have become starting points to address broad evolutionary questions and to better understand the genetic basis of many human diseases. Researchers in the program have already used the yeast genetic map to study parallel interactions in human cells - in this case an interaction associated with a certain cancer. A mutation in this genetic network causes tumour growth. That means the tumor cells might be susceptible to “selective killing,” where one of the mutated genes is “knocked out,” destroying the tumor cell. Healthy cells don’t have the mutation, and are therefore unaffected.

Members are also working with an international team to study autism spectrum disorders, which are known to involve multiple genes. This research exemplifies the potential to forecast better the likelihood that individual will develop particular diseases, and to learn how to stop these diseases before they start.

Through this program, CIFAR has also helped to recruit eminent researchers from the United Kingdom and the United States to conduct their work in Canada.