Where in the genome are there genes that cooperate?

Interdisciplinary project analyzing genetic data

Cancer is one example of a partially hereditary disease that is associated with several different genes. The risk of contracting cancer is a so-called polygenic trait. At the Department of Information Technology a team of researchers is developing computational methods for determining where in the genome there are genes that influence polygenic traits in animals.

What we look like, how quickly we grow, and how susceptible we are to disease depends largely on our genes. Traits that are influenced by several genes are called polygenic traits. An individual´s risk of developing cancer is one example of such a trait, meat quality in pigs is another. The project is a collaboration between researchers in genetics, statistics, and scientific computing. Genetic data from a group of animals is used to formulate a statistical problem. The computational task is to calculate the solution to this problem, i.e. to find out where in the genome the interesting genes are located.

The study of both meat quality and cancer is complicated by the fact that the underlying genes can work together as a team. This means that we must look for several genes simultaneously, which entails gigantic multidimensional optimization problems. One can compare this to selecting players for a soccer team. If there are 25 players to choose from, there are more than 4 million possible ways to pick a team of 11 players. It is impossible to test all teams, but on the other hand it is not enough to study how single players handle the ball on an empty field, the most important thing for the success of the team is how the players perform together. The genetic analysis is further complicated by environmental influences on the traits, and by the fact that we do not know how many genes are involved in each case.

Kajsa Ljungberg