MORPHOGENESIS OF THE SILKMOTH CHORION - PATTERNS OF DISTRIBUTION AND INSOLUBILIZATION OF THE STRUCTURAL PROTEINS

The morphogenesis of the silkmoth eggshell (chorion) is a complex process of extracellular distribution and insolubilization of secreted proteins. At various stages during chorion development, the secreted proteins establish a structural framework, permeate into the interstices of that framework, or are deposited superficially, immediately adjacent to the secretory cell surface. Secreted proteins rapidly reach their respective extracellular sites. However, insolubilization of the proteins occurs slowly and can be divided into two major sequential processes: fixation (development of resistance to extraction; chorion solubilized with difficulty in water or SDS in the absence of a reductant) and cementing (development of total resistance to extraction; chorion solubilized only once reduced). Certain chorion proteins exhibit unusual susceptibility to extraction. © 1979.