From harmless to harmful

31 Jan 2012

Stramenopiles are a major and diverse line of eukaryotic organisms, predominantly algae, but also including the generally pathogenic oomycetes. One of the most notorious oomycetes species is Phytophtora infestans, which causes late blight in potato.

Oomycetes are known to have flexible genomes. To learn more about the evolutionary processes that shaped gene content and the origin of the oomycetes' pathogenicity (in contrast to the non-pathogenic nature of the algae they are related to), Michael Seidl (Utrecht University) and colleagues applied systemic tree reconciliation. They focused on ten Stramenopiles (algae and oomycetes) and were able to reconstruct  a last common ancestor that contained appr. 10,000 genes.

It appears that throughout evolution, the oomycetes genomes underwent a continuous flow of gene duplication and gene loss. According to Seidl et al., the branch leading to the notorious Phytophtora genus marks a major transition point in oomycetes evolution.

Seidl MF, van den Ackerveken G, Govers F, Snel B
Reconstruction of oomycete genome evolution identifies differences in evolutionary trajectories leading to present-day large gene families.
Genome Biol Evol. 2012 Jan 13

By: Esther Thole

To NBIC news list