Sulfate and glucosamine labelling of the intercellular matrix in vitellogenic follicels of a moth.

InHyalophora cecropia the intercellular spaces of the follicles contain during vitellogenesis a matrix that can be labelled eitherin situ or in culture with35S-sulfate and3H-glucosamine. The matrix was demonstrated by autoradiography and also by treating follicles for 15 min with pronase, which released TCA-soluble matrix fragments with molecular weights of up to 2×106 daltons. Testicular hyaluronidase degraded the high molecular weight fragments, and thus it is probable that they are chondroitin sulfate-like mucopolysaccharides. With the termination of vitellogenesis new matrix is no longer deposited, and the pre-existing material is disassembled. The sulfated matrix may account for the patency of the intercellular diffusion channels essential for blood protein uptake and also for the low level, extracellular binding of blood proteins that characterizes the vitellogenic follicle inHyalophora.