PROCEEDINGS OF THE SCHISTOSOME GENOME PROJECT

''The host-parasite relationship'' is a vast and diverse research fiel d which, despite huge human and financial input over many years, remai ns largely shrouded in mystery. Clearly, the adaptation of parasites t o their different host species, and to the different environmental str esses that they represent, depends on interactions with, and responses to, various molecules of host and/or parasite origin. The schistosome genome project is a primary strategy to reach the goal, this systemat ic research project has successfully developed novel technologies for qualitative and quantitative characterization of schistosome genes and genome organization by extensive international collaboration between top quality laboratories. Schistosomes are a family of parasitic blood flukes (Phylum Platyhelminthes), which have seven pairs of autosomal chromosomes and one pair of sex chromosomes (ZZ for a male worm and ZW for a female), of a haploid genome size of 2.7x10(8) base pairs (Simp son et al. 1982). Schistosomes are ideal model organisms for the devel opment of genome mapping strategies since they have a small genome siz e comparable to that of well-characterized model organisms such as Cae norhabditis elegans (100 Mb) and Drosophila (165 Mb), and contain func tional genes with a high level of homology to the host mammalian genes . Here we summarize the current progress in the schistosome genome pro ject, the information of 3,047 transcribed genes (Expressed Sequence T ags, EST), complete sets of cDNA and genomic DNA libraries (including YAC and cosmid libraries) with a mapping technique to the well defined schistosome chromosomes. The schistosome genome project will further identify and character the key molecules that are responsible for host -parasite adaptation, i.e., successful growth, development, maturation and reproduction of the parasite within its host in the near future.