INFLUENCE OF HEAVY-METALS (CADMIUM AND LE AD) ON VITELLOGENIN PRODUCTION IN THE CENTIPEDE LITHOBIUS-FORFICATUS (LINNE)

Vitellogenin was identified in the hemolymph of mature Lithobius forfi catus and partially characterized by polyacrylamide gel electrophoresi s. Two major protein bands with apparent molecular weight of about 360 and 450 kDa stained with Sudan Black B anti PAS reagent were identifi ed as lipoglycoproteins and defined as vitellogenins. The same protein bands were present in the hemolymph of females, and, to far lower lev els, in males. Variation in vitellogenin production from contaminated and uncontaminated areas may be interpreted rather as a microclimatic response than a direct effect of heavy metals on vitellogenesis. In co ntrast, when cadmium or lead was injected in animals, a significant de crease in vitellogenin levels was observed, compared to unpolluted con trols, providing evidence for a physiological process of compensation. As a consequence, the production of vitellogenin in natural populatio ns of centipedes may not be useful as a biomarker for these chemicals.