August 17, 2009

Blood parasite genetic linkage map created

A U.S. scientist says he has completed the first genetic linkage map for Schistosoma mansoni -- a blood parasite linked with schistosomiasis.

S. mansoni is a complex and aggressive pathogen affecting more than 90 million people in Africa, the Middle East and South America, Texas A&M University Assistant Professor Charles Criscione said. Schistosomiasis is a debilitating, chronic disease that can damage internal organs and impair growth in children.

Criscione and his team of researchers said their map will be useful in piecing together the S. mansoni genome sequence, which is in 19,000 fragments. And, because it is the first genetic map for a platyhelminth (flatworm) species, it will also be a platform for other flatworm genomics, he said.

The linkage map we constructed will help assemble the genome and will serve as a useful genetic tool to help find genes that control important traits, such as drug resistance, virulence and host specificity, Criscione said. It has been shown that the parasite can vary for many of these traits. Knowledge of genomic regions that affect these traits will help identify new targets for drugs and vaccines and may help identify parasite genes involved in pathology.

The study appears in the online version of the journal Genome Biology.