Abstract
The cell ultrastructure of the VAM fungus Gigaspora margarita was examined, and its N-acetylglucosamine content and distribution were assessed by means of WGA/ovomucoid-gold labelling. The various ontogenic stages of the fungus were studied with particular reference to cell walls. The results provide new information on chitin incorporation during spore wall development. A decrease of chitin was observed which was correlated to the structural simplification of the fungus wall throughout its life-cycle. This suggests an involvement of chitin in specific biological functions such as mechanical resistance and plasticity.