Gender-specifically expressed genes in Schistosoma mansoni

Using a genomic gene bank in phage lambda and two cDNA banks in the expression vector lambda-gt11 we have cloned and characterized genes that are expressed preferentially or exclusively in females. One of these genes transcribes two predominant RNA molecules of 0.8 and 3.9 kb which comprise more than 5% of the mRNA population of adult female worms. Transcription of these two RNAs occurs in close proximity on the genome, probably in an overlapping fashion. Experiments are presently in progress to sequence the genes and to produce antibodies against their polypeptide products which will be used to determine in which tissue and at what time in development these genes are expressed. The gene products are probably used for egg shell formation. The final long-term perspective of this project is to interfere with the schistosome parasite's cycle and to reduce its pathogenicity by interrupting egg production.