Effects of mycostatin in sea urchin development.

Sea urchin development is inhibited in the presence of mycostatin, a fungicidal antibiotic believed to alter cell membranes. Pretreatment of eggs inhibits fertilization inL. pictus, but not inS. purpuratus. The doses resulting in abnormal development inS. purpuratus increase as the treatment is started later in development. AH tissues are sensitive to mycostatin at high concentrations, but the endodermal and mesenchyme derivatives are most sensitive at lower concentrations. The results suggest the heterogeneity of cell membranes and also indicate that membranes change with time of development.