Volker Wippersteg, Katja Kapp, Werner Kunz, and Christoph G Grevelding, Institute for Genetics, Center of Biological and Medical Research, Heinrich-Heine-University, D-40225 Dsseldorf, Germany
Schistosomes are parasitic helminths that cause bilharzia (schistosomiasis) in humans, a tropical disease of worldwide significance (Savioli et al.1997). One focus of international research on such pathogens is to increase the understanding of their molecular biology and to identify and characterize genes with key cellular functions. These genes could be new targets for the development of drugs and vaccines (Johnston et al. 1999).
Gene transfer in homologous systems has been shown to be a powerful tool for the functional analysis of genes and their regulatory elements (Buono and Linser 1992). However, there is comparatively little documentation of attempts to transform multicellular parasites. The goal of our study was to establish a gene delivery system for Schistosoma mansoni, a digenean trematode with a complex life cycle. Specifically, we used biolistic gene transfer techniques to transiently transform adult and larval stages of the schistosome.
Biolistic gene transfer, also known as particle bombardment, was initially
designed to transform plants; however, several other types of organisms
have been successfully transformed using the Helios gene gun and the
PDS-1000/He particle delivery system, both from Bio-Rad (Williams et al. 1991, Schiedlmeier et al. 1994, Davis et al. 1999, Jackstadt et al.
1999, Hara et al. 2002). The principle of biolistics is based on the acceleration
of DNA- or RNA-coated microparticles by high-pressure helium. These particles
are able to