| Abstract: | The microtubules in the nutritive tubes of telotrophic insect ovaries, like those in many other situations, are surrounded by an electron clear zone or ‘sleeve’ after conventional preparative procedures for electron microscopy. Ribosomes, which also pack the nutritive tubes, do not encroach into this region, and although microtubules are often closely opposed, they are rarely seen to touch. The composition of the microtubule sleeve zone is unknown. This study shows that colchicine not only destroys the microtubules in the nutritive tubes, but also the sleeve zone which surrounds them, suggesting that the integrity of the microtubules is essential for the existence of the sleeves. |
