“The fly” returns to stardom

(article from the PRBB newspaper el·lipse, December issue)

It is the biggest genomic comparison in history, and it has allowed to start understanding the evolutive processes that have taken place during the last 100 years in Drosophila, the most used insect model organism.

The IMIM researchers Charles Chapple and Roderic Guigó, director of the Bioinformatics and Genomics programme of the CRG, have been co-authors of the article in Nature that compares the genomes of 12 out of the 1,500 species of Drosophila. The study, done by an international consortium of more than 100 institutions, has revealed, amongst other things, sequences that have been preserved through the years and that are probably important for the organism. Within the consortium, Charles Chapple has studied the genes that codify for selenoproteins. This part of the study has given rise to an unexpected finding.

Selenoproteins are implied, amongst other things, in the protection against oxidative stress and toxic effects of selenium. So far it was thought that these proteins were essential for animal life. But this study identifies one of the analysed species, Drosophila willistoni, as the first animal which does not contain selenoproteins. Why this organism has lost selenoproteins is still a mystery, but the group has already started to study the possible reasons and consequences.

The major difficulty of the project, says Chapple, was that “the amount of data was inhuman”. But it’s been worth it. Taking into account that about 61% of the human genes implied in diseases have an equivalent in Drosophila, this study can be an important step to their understanding.