Ultrastructure of spherites in the midgut diverticula and Malpighian tubules of the harvestman Amilenus aurantiacus during the winter diapause

Hazards related to the presence of cadmium in food - Studies on the European soil centipede, Lithobius forficatus

The soil is an environment rich in numerous potentially toxic substances/elements when present at elevated concentrations. They can be transported through the successive levels of the trophic chain. Animals living in a contaminated environment or eating contaminated food can accumulate potentially toxic elements in their bodies. One of the potentially toxic metals is cadmium, which accumulates significantly in soils. The aim of our research was to evaluate the changes caused by cadmium supplied with the food administered to invertebrates living in uncontaminated soil. The results were compared with those obtained for animals raised in contaminated soil, where cadmium entered the body via the epidermis. As the material for studies, we chose a common European soil centipede, Lithobius forficatus. Adult specimens were divided into the following experimental groups: C - control animals, Cd12 and Cd45 - animals fed with Chironomus larvae maintained in water containing 80 mg/l CdCl₂, for 12 and 45 days, respectively. The material was analyzed using qualitative and quantitative analysis (transmission electron microscopy, confocal microscopy, flow cytometry, atomic absorption spectrometry). Eventually, we can conclude that the digestive system is an effective barrier against the effects of toxic metals on the entire organism, but among the gonads, ovaries are more protected than testes, however, this protection is not sufficient. Accumulation of spherites and mitochondrial alterations are probably involved in survival mechanisms of tissues after Cd intoxication.

Ovaries and testes of Lithobius forficatus (Myriapoda, Chilopoda) react differently to the presence of cadmium in the environment

Proper reproduction depends on properly functioning gonads (ovaries and testes). Many xenobiotics, including heavy metals, can cause changes in somatic and germ line cells, thus damaging the reproductive capacity. The aim of this study was to investigate the effect of the heavy metal cadmium on the gonads, including germ line and somatic cells. It is important to determine whether cell death processes are triggered in both types of cells in the gonads, and which gonads are more sensitive to the presence of cadmium in the environment. The research was conducted on the soil-dwelling arthropod Lithobius forficatus (Myriapoda, Chilopoda), which is common for European fauna. Animals were cultured in soil supplemented with Cd for different periods (short- and long-term treatment). Gonads were isolated and prepared for qualitative and quantitative analysis, which enabled us to describe all changes which appeared after both the short- and long-term cadmium treatment. The results of our study showed that cadmium affects the structure and ultrastructure of both gonads in soil-dwelling organisms including the activation of cell death processes. However, the male germ line cells are more sensitive to cadmium than female germ line cells. We also observed that germ line cells are protected by the somatic cells of both gonads.