Molting in a parasitic nematode, Phocanema decipiens. III. The histochemistry of cuticle deposition and protein synthesis

Abstract

The adult cuticle of Phocanema decipiens is deposited at the edge of the hypodermis as three discrete layers of protein, each having the same histochemical characteristics. The cortex, or outermost layer, is keratinized at the periphery as soon as it appears, and later differentiates into two layers. The middle layer, or matrix, differentiates into three bands, apparently by further secretion of material from the hypodermis. Cytoplasmic and nucleolar ribonucleic acid (RNA) in both hypodermis and muscle cells increases during cuticle deposition, even when the worms are deprived of nutrients. A cycle of nucleolar secretion also occurs in the muscle cells, but this is shown to be correlated with nutrition rather than with cuticle deposition.