Cloning of the SmSPO-1 gene preferentially expressed in sporocyst during the life cycle of the parasitic helminth Schistosoma mansoni

Schistosomes are parasitic helminths with a complex life cycle in human and snail hosts. They express stage-specific genes that conceivably determine distinct properties of the parasite at different developmental stages. Here we report the stage-specific gene SmSPO-1, which is preferentially express ed in sporocysts residing in the snail host. The cDNA and the gene were clo ned and sequenced. The cDNA. from cap site to the poly(A) addition site, is 498 bp long. It encodes a protein of 117 amino acids with a hydrophobic si gnal peptide of Is residues, indicating that SmSPO-1 is a secreted or a mem branal protein. In the gene the cDNA is split into four exons spread over 2 .1 kb of chromosomal DNA. (C) 1999 Elsevier Science B.V. All rights reserve d.