Ultrastructure ofAspergillus nidulans conidia and conidial lomasomes

Summary Lomasomes in the conidia ofAspergillus nidulans can be divided into at least two distinct structures. The first is a twice double membrane bound core of cytoplasmic origin. The outermost membrane of the lomasome becomes incorporated into the plasmalemma as it migrates to rest next to the cell wall. The second lomasome structure appears to be a triangle shaped series of tubules arranged in a parallel fashion. The wide end next to the cell wall connected to the plasmalemma and the opposite end to an element of the endoplasmic reticulum. The term membranosome has been coined to designate this lomasome structure with its function of plasmalemma extension. Various structures of the conidium such as wall, endoplasmic reticulum and the cytoplasmic matrix undergo changes from the conidial chain stage to the free or resting conidial stage. This suggests that after conidiation and before the resting stage, the conidium continues to mature.