Abstract
Evidence of a distinct microtubule organizing center in the meiotic apparatus of the fertilized Drosophila egg is provided by means of specific antibodies. This center contained gamma-tubulin and CP190 antigens and nucleated a transient array of radial microtubules. When the eggs were incubated with the microtubule-depolymerizing drug colchicine, gamma-tubulin became undetectable in correspondence with the meiotic chromosomes, whereas it was visible near the sperm nucleus. Since the main difference between male and female microtubule organizing centers was the presence/absence of the centrioles, we propose that these organelles were mainly involved in the spatial organization of the microtubule nucleating material.
