Who would have thought that studying the genes responsible for a coat colour of the Belgian Blue would lead to the discovery of a new mechanism responsible for creating genetic variability? And yet this is what happened to Carole Charlier and her colleagues at the Unit of Animal Genomics. The results of their research were published in the journal Nature at the beginning of February.
They are almost as much a part of our landscape as the furniture in our homes. You simply have to step outside of town to find them grazing in the fields. After more than 10,000 years of domestication, cows have become such common animals that although we humans regard them fondly, we often pass them by without a second thought. But while we might pay little attention to cattle, “cow” patterns, on the other hand, have aroused great interest. Indeed, the white coat with black spots is very fashionable, decorating bibs, dressing gowns, cushions, telephone covers, umbrellas, shoes, bins and other products.
However, cows’ coats are not only of interest to the fashionistas. Carole Charlier, a qualified F.R.S.-FNRS researcher and project leader at GIGA’s Unit of Animal Genomics, and her colleagues are also interested in them. “This study results from a research programme on the Belgian Blue variety aimed at mapping simple monogenic traits, i.e., characteristics determined by a single gene, which have a major agronomic effect. These characteristics can either be characteristics arising from production, defects or economically debilitating diseases”, the researcher explains. Usually, this type of characteristic is recessive and therefore requires two copies of the mutation so that the individual presents the phenotype associated with it. “You can find the gene and the mutations responsible for a phenotype by studying the whole genome thanks to statistical analysis programmes that allow you to locate these characteristics”, Carole Charlier points out. “For recessive diseases, this type of programme has been perfected and we would like to develop the same type of analyses for dominant characteristics”, she continues. In the case of the the Belgian Blues, they have a dominant phenotype regarding a particular colouring of their coat. This is translated into pigmented sectors on the flanks and a white band along their spine known as “lineback”. “We thus hope to be able to identify new genes involved in bovine coat colour because these genes frequently have other more important effects on characteristics. For instance, in mice, some genes that play a role in the colour of these rodents’ coats are also associated with effects on fertility or obesity”, Carole Charlier elaborates.