Cytophotometric study of nuclear proteins during gametogenesis in Ascaris lumbricoides

Abstract

Microspectrophotometric analyses of histone and basic nuclear proteins indicated that characteristic changes occur during the development of male and female gametes in Ascaris lumbricoides. The lysine-rich histone/Feulgen-DNA ratio varies slightly during spermatogenesis, whereas the arginine-rich histone/Feulgen-DNA ratio increases prior to meiosis and then dramatically decreases during spermiogenesis. Similarly, both the Sakaguchi-arginine/Feulgen-DNA and fluorodinitrobenzene-lysine plus tyrosine/Feulgen-DNA ratios increase as the spermatocytes develop and than fall after meiosis. Low levels of both histone and basic protein are retained by the nuclear material of the mature sperm. The Feulgen-DNA values of sperm are hypohaploid. Both the arginine-rich and lysine-rich histone/Feulgen-DNA values increase as the primary oocytes mature. Concomitantly, there is a steady accumulation of basic nuclear proteins as revealed by binding of the Sakaguchi reagent and fluorodinitrobenzene. Feulgen stainability is abruptly lost as the primary oocytes reach the terminal quarter of the reproductive tract thereby precluding further quantitation. There is no demonstrable evidence for a nuclear to cytoplasm transfer of basic proteins during either gametogenic process.