A NEW-TYPE OF MANCHETTE STRUCTURE IN SPERMATIDS OF CULEX-TIGRIPES (CULICIDAE)

In young spermatids of Culex tigripes, microtubules organize a manchet te which surrounds the nucleus. When the nucleus elongates, 1-5 expans ions appear on the wall of the microtubules. They grow and branch out while the nucleus elongates and chromatin condenses. Expansions are st raight or curved in shape. They have the same thickness as the microtu bule walls, but they rarely constitute links between microtubules. The manchette disappears naturally at the end of spermiogenesis. The acti on of colchicine on spermatids leads to the complete disappearance of the microtubules and expansions, and inhibits the lengthening of the n ucleus.