Host-like sequences in the schistosome genome

A series of recent papers has indicated that widespread genomic rearrangements take place in the genome of schistosomes during the life cycle of the parasite. These results have been controversial since genomic rearrangements are not common in eukaryotes, probably because excessive genome plasticity would carry a heavy evolutionary price. Here, Karen Clough, Alec Drew and Paul Brindley present data that ostensibly support the concept of widespread genomic rearrangements, but for which they suggest a different interpretation. They conclude that artefactual contamination of schistosome genome preparations with host DNA can probably explain the Southern hybridization results which led to the original hypothesis of developmental, genomic rearrangements.