Effect of long-term cadmium and copper intoxication on the efficiency of ampullate silk glands in false black widow Steatoda grossa (Theridiidae) spiders.

The aim of the study was to compare cellular effects of xenobiotic cadmium and biogenic copper in ampullate silk glands of false black widow Steatoda grossa spider after long-term exposure via ingestion under laboratory conditions. Both the level of selected detoxification parameters (glutathione S-transferase, catalase, and the level of total antioxidant capacity) and degree of genotoxic changes (comet assay) were determined in the silk glands. Additionally the contents of selected amino acids (L-Ala, L-Pro, L-His, L-Phe, DL-Ile, and DL-Asn) in the hunting webs produced by spiders of this species were assessed. The ability of S. grossa females to accumulate cadmium was higher than that for copper. Long-term exposure of spiders to copper did not change the level of detoxification parameters, and the level of DNA damage in the cells of ampullate silk glands was also low. Cadmium had a stronger prooxidative and genotoxic effect than copper in the cells of the analyzed silk glands. However, regardless of the type of metal used, no significant changes in the level of amino acids in silk were found. The obtained results confirmed the effectiveness of metal neutralization mechanisms in the body of the studied spider species, which results in the protection of the function of ampullate silk glands.

Evaluation of selected biological properties of the hunting web spider (Steatoda grossa, Theridiidae) in the aspect of short- and long-term exposure to cadmium.

The study aimed at comparing the effects of short- and long-term exposure of Steatoda grossa female spiders to cadmium on the web's architecture, its energy content, and ultrastructure of ampullate glands. Simple food chain model (medium with 0.25 mM CdCl2 → Drosophila hydei flies → spider (for 4 weeks or 12 months) was used for the exposure. Analysis of Cd content provided evidence that silk fibers of the web are well protected against its incorporation irrespectively of the exposure period. Long-term exposure to cadmium resulted in the occurrence of numerous autophagosomes with degenerated organelles as well as apoptotic and necrotic cells in the ampullate glands. Concurrently, the individual silk fibers building double and multiple combination complexes were significantly thinner than in the control threads. Moreover, exposed spiders spun net with smaller mean calorific value than did the control individuals. Hence, evaluation of both the diameter of silk fibers and calorific value of the web can serve as biomarkers of the effects caused by exposure of these predators to cadmium.