Blood flukes of the genus Schistosoma (Platyhelminthes, Trematoda, Digenea) are responsible for the chronic debilitating disease schistosomiasis / bilharzia, widely considered to be second only to malaria as a global health problem and an incalculable drain on the economic development of endemic countries.
Since 1994, the World Health Organization has supported a genome initiative for Schistosoma, the Schistosoma Genome Network, aimed at identifying new targets for drug and vaccine development, understanding the molecular basis of parasite metabolism and development and determining biological variation. That initiative developed, and continues to develop, resources and datasets that have provided a firm foundation from which large scale mapping and sequencing efforts have been launched.
Schistosoma mansoni possesses 7 pairs of autosomes and one pair of sex chromosomes (female = ZW, male = ZZ). Chromosomes range in size from 18 to 73 MB and can be distinguished by size, shape and C banding. A draft genome has been produced by the Wellcome Trust Sanger Institute in collaboration with The Institute for Genomic Research using a whole genome shotgun sequencing strategy. Approximately 3.8 million pooled reads have been produced by the two genome centres and have been assembled using the Phusion assembly algorithm. The draft genome is 363Mb and encodes at least 11,809 genes. Further work is underway on the genome.
A first draft of the S. mansoni genome has been published (PMID:19606141) and is available for browsing from GeneDB. Sequencing is continuing and further assemblies will be available from this site, prior to publication.
In collaboration with Prof. Alan Wilson (University of York), expressed sequence tags from the following life cycle stages have been produced: day 21 liver worms (mouse host), day 28 liver worms (mouse), day 28 liver worms (rat), day 7 lung stage, intramolluscan germ ball, cercariae, day 3 schistosomule.
Further characterisation of the life cycle using high-thoughput second generation sequencing (RNA-Seq) is ongoing.
A systematically improved high quality genome and transcriptome of the human blood fluke Schistosoma mansoni.
PLoS neglected tropical diseases 2012;6;1;e1455
The genome of the blood fluke Schistosoma mansoni.