Cell Differentiation

The spermatozoa from the shrimp Palaemon serratus have been studied with respect to their morphological and biochemical characters. At the ultrastructural level the acrosomal vesicle of the nail-shaped spermatozoon displays a periodically striated bundle. This appearance seems to be characteristic for the Palaemonidae. The biochemical parameters of the chromatin, extracted from the spermatozoa, have been compared with those obtained from the testes and the hepatopancreas. The basic proteins of testes and sperm have been characterized by polyacrylamide gel electrophoresis. Protamines appear to be absent in the sperm of P. serratus. On the contrary, histones with a somatic character remain present. Moreover, supplementary histone fractions have been identified. These proteins have been further studied after purification on Biogel P-100. Their amino acid composition shows similarities to that of the H2A and H2B histone and has a molecular weight of 15,500±300.