Spontaneous sexual differentiation of Mesocestoides corti tetrathyridia in vitro

Abstract

Barrett N. J., Smyth J. D. and Ong S. J. 1982. Spontaneous sexual differentiation of Mesocestoides corti tetrathyridia in vitro. International Journal for Parasitology 12: 315–322. Tetrathyridia of Mesocestoides corti, from the body cavity of mice, maintained in the laboratory by intraperitoneal infection, were used for in vitro culture. In an initial experiment, after 50 days asexual multiplication in vitro one tetrathyridium spontaneously segmented and developed into a sexually mature adult. Further experiments were carried out in an attempt to determine the conditions favouring segmentation and sexual differentiation. A combination of 5 or 10 ml liquid medium S1OE.H (basically composed of CMRL 1066 and foetal calf serum with supplements) changed every 3 days, in a Leighton tube (19 × 105 mm), rotated at 38°C and gassed with 10 or 20% CO 2, containing between 100 and 200 tetrathyridia, has proved to be most suitable so far. Numerous adult worms with normal male and female genitalia have been obtained in this system. However, segmentation is sporadic, rather than consistent and only a few shelled eggs with hooked oncospheres have so far been obtained, suggesting that impregnation and fertilization in vitro is not fully comparable with that in vivo.