Schistosoma mansoni: protein composition and synthesis during early development; evidence for early synthesis of heat shock proteins.

There are alterations in the proteins synthesized during different stages of development of Schistosoma mansoni. The protein profiles at different stages were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. When stained by Coomassie blue, no significant differences were seen in protein profiles derived from cultured schistosomula from Days 0 to 6 and from adults. Newly synthesized proteins were detected by [35S]methionine incorporation. There were only a few differences in the protein profiles of schistosomula from Days 1 to 6 and from adults. Profiles derived from Day 0 schistosomula showed striking differences. Only a few proteins appear to be synthesized on Day 0 under these conditions. Schistosomula on Day 0 synthesized several minor proteins as well as a major protein of approximately 69,000 Da. This protein was immunoprecipitated by rabbit antiserum against bovine uncoating adenosine triphosphatase which recognizes the constitutive and induced 70,000 Da heat shock proteins in a wide variety of eukaryotic cells. More significant differences were observed when the newly synthesized proteins were analyzed by two dimensional gel electrophoresis. The profiles of newly synthesized proteins showed a specific repertoire of expression during the early stages of development in the parasite. A shift in temperature and medium during transformation from aquarium water to isotonic medium may initiate the synthesis of heat shock protein in these parasites.