[The action of tiazofurin on the development of sea urchin embryos and larvae].

The effects of the antitumor drug tiazofurin on development of sea urchins Sphaerechinus granularis, Paracentrotus lividus, Strongylocentrotus intermedius, and Arbacia lixula were studied. When 0.01-200 microM tiazofurin (TAF) was introduced in the incubation medium (artificial sea water) just after fertilization or at the midblastula stage, the development proceeded quite normally until the beginning of gastrulation. But later TAF blocked gastrulation and induced formation of mobile ball-shaped larvae with normal pigment cells but devoid of the nervous system, skeletal spicules and digestive tract. The threshold TAF concentrations varied from 0.05 microM (S. granularis) to 2-5 microM (all other species). When TAF was introduced during gastrulation and just after gastrulation, the larvae had defective nervous system and skeleton and suppressed expression of gangliosides. The nonhydrolyzable analog of GTP, GTP-gamma-S (5-20 microM), introduced in artificial sea water no later than at the midblastula stage prevented all above mentioned developmental defects.