Variabilité biochimique et génétique de Sphaeroma ghigii,S. hookeri et S. serratum. Variations intraspécifiques

Electrophoresis on polyacrylamide gel of enzymes (esterases, phosphatases) and total proteins of Sphaeroma ghigii, S. hookeri and S. serratum shows the existence of important intraspecific variability. Esterases, alkaline phosphatases and major low ionic strength extractable proteins also demonstrate quantitative and qualitative differences between individuals; these differences are the expression of protein and enzyme polymorphism. Some of these variations represent sexual differences which are an expression of a biochemical sexual dimorphism that appears particularly in esterases and phosphatases. Among males, this variability leads to the delineation of several biochemical phenotypes and gives an insight into the genetic variability of populations based on the protein composition of organisms. Taking into consideration the ecological characteristics of the various species of genus Sphaeroma, this polymorphism provides a source of information on ecophysiological relations at the level of proteins and enzymes, that may lead to a better understanding of intraspecific variability.