Protein turnover in the cytoplasmic transport system within an insect ovary--a clue to the mechanism of microtubule-associated transport.

The movement of radioactively labelled polypeptides into the microtubule-associated transport channels in the ovaries of a hemipteran insect has been analysed using SDS-polyacrylamide slab gel electrophoresis and fluorography. The patterns of label suggest that the microtubules which pack the transport channels form a relatively static cytoskeleton while other components move independently from them along the channels. As well as illustrating the functional organisation of microtubule-associated transport in this system our studies of labelled proteins have also provided clues as to the mechanism of transport itself.