Effects of stressful conditions on the development and movement of reproductive cells in Schistosoma japonicum.

Adult S. japonicum exposed to 3H-thymidine to label reproductive cells were cultured in vitro, maintained intraperitoneally, or transplanted as unisexual infections to hamsters. Daily samples were taken, processed for autoradiography, and observed for abnormal morphological and developmental characteristics. By day 5 of in vitro culture in Medium 199 and calf serum, all worms were dead. The vitelline system was the most sensitive to culture conditions and labeled vitelline cells never moved from the gland area. No labeled sperm were produced by males and evidence of deterioration of the testes was apparent by day 2. Degenerative changes of the ovary were the last to appear, on day 3. Most adults transplanted to the peritoneal cavity of hamsters were dead by day 3, but some lived for 6 days. No movement or development of reproductive cells was detected in these worms. An intense cellular reaction directed against the tegument was observed as early as day 1. Males transplanted in groups to the hepatic portal system were maintained normally in vivo and produced labeled sperm in 6 days. Females handled similarly showed degenerative changes in their genitalia by day 2, but most were alive after 6 days.

The timing of reproductive cell development and movement in Schistosoma mansoni, S. japonicum, and S. haematobium, using techniques of autoradiography and transplantation.

Tritiated thymidine was incorporated into gonial and vitelline cells of male and female Schistosoma mansoni, S. japonicum, and S. haematobium after 2 hr of incubation. Spermatogonial cells developed into labeled mature sperm after 6 days of transplantation in all species. Insemination of females was detected on the same day indicating copulation is frequent. Oogonia labeled in the initial incubation matured into primary oocytes after 7 days of transplantation for S. mansoni and S. haematobium and after 6 days in S. japonicum. Cytoplasmic thymidine label was observed after 2-hr incubations in the primary oocytes of all species. Initial label in the vitellaria was scattered and heavy. After 3 days of transplantation, label was considerably diluted and by day 6 was undetectable in vitelline glands. These times for development and movement of reproductive cells are considered to be standards against which the effects of stressful conditions on the reproductive system can be assessed.