Ataev G L, Fournier A, Coustau C
Department of Invertebrate Zoology, Saint-Petersburg University, Russia.
J Parasitol. 1998 Apr;84(2):227-35.
Biomphalaria glabrata embryonic (Bge) cells have previously been shown to permit a successful cocultivation of Schistosoma mansoni and Schistosoma japonicum from miracidia to mother sporocysts (MS) and then to the production of daughter sporocysts (DS). To investigate further the properties of the Bge culturing system we used Echinostoma caproni under identical in vitro conditions. In vitro-derived miracidia were used either for experimental infections of B. glabrata snails, or for in vitro cultivation with Bge cells. Histological analysis showed that the development of MS in B. glabrata was similar to the previously described development in Biomphalaria pfeifferi in terms of final site of infection, development dynamics, growth dynamics, reproduction intensity, and life spans. Only short delays in migration dynamics were observed in B. glabrata. When cultivated under in vitro conditions, E. caproni MS could live for up to 17 wk in the presence of Bge cells, as compared with 2 wk in cell-free Bge medium. The presence of Bge cells also permitted significant growth of MS and development through complete embryogenesis of the next intramolluscan stage (embryos of 100-110 cells). However, degeneration of MS consistently occurred before production of this second generation. During the entire cultivation period, no visible contact was observed between MS and Bge cells, suggesting that development of MS was only triggered by soluble factors released by Bge cells.
光滑双脐螺胚胎（Bge）细胞先前已被证明能够成功地将曼氏血吸虫和日本血吸虫从毛蚴培养至母胞蚴（MS），进而培养出子胞蚴（DS）。为了进一步研究Bge培养系统的特性，我们在相同的体外条件下使用了卡氏棘口吸虫。体外获得的毛蚴要么用于对光滑双脐螺进行实验性感染，要么用于与Bge细胞进行体外培养。组织学分析表明，光滑双脐螺中母胞蚴的发育在感染的最终部位、发育动态、生长动态、繁殖强度和寿命方面与先前描述的费氏双脐螺中的发育相似。在光滑双脐螺中仅观察到迁移动态有短暂延迟。在体外条件下培养时，卡氏棘口吸虫母胞蚴在有Bge细胞存在的情况下可存活长达17周，而在无细胞的Bge培养基中仅存活2周。Bge细胞的存在还使母胞蚴显著生长，并通过下一螺内阶段（100 - 110个细胞的胚胎）的完全胚胎发育。然而，在第二代产生之前母胞蚴始终会发生退化。在整个培养期间，未观察到母胞蚴与Bge细胞之间有明显接触，这表明母胞蚴的发育仅由Bge细胞释放的可溶性因子触发。
