Effect of cadmium on gonadogenesis and metamorphosis in Pleurodeles waltl (urodele amphibian)

• Published in: Aquatic toxicology Vol. 64; no. 2; pp. 143 - 153
• Main Authors: Flament, S., Kuntz, S., Chesnel, A., Grillier-Vuissoz, I., Tankozic, C., Penrad-Mobayed, M., Auque, G., Shirali, P., Schroeder, H., Chardard, D.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 16.07.2003; Elsevier Science
• Subjects: Amphibia; Amphibian; Analysis of Variance; Animal, plant and microbial ecology; Animals; Applied ecology; Biological and medical sciences; Cadmium; Cadmium - toxicity; Dose-Response Relationship, Drug; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on protozoa and invertebrates; Effects of pollution and side effects of pesticides on vertebrates; Environmental Pollutants - toxicity; Female; Freshwater; Fundamental and applied biological sciences. Psychology; Gonadal Steroid Hormones - antagonists & inhibitors; gonads; Gonads - drug effects; Hormone Antagonists - toxicity; Larva - drug effects; Larva - growth & development; Lethal Dose 50; Male; Metamorphosis; Metamorphosis, Biological - drug effects; Organogenesis - drug effects; Pleurodeles - anatomy & histology; Pleurodeles - growth & development; Pleurodeles waltl; Reptilia. Amphibia; Sex determination; Sex Determination Analysis; Sex differentiation; Sex Differentiation - drug effects; steroids; Time Factors; Cadmium; Sex determination; Sex differentiation; Metamorphosis; Amphibian; Vertebrata; Toxicity; Caudata; Amphibia; Development; Pleurodeles waltl; Pollutant effect; Sexual differentiation; Heavy metal
• ISSN: 0166-445X; 1879-1514
• DOI: 10.1016/S0166-445X(03)00042-0

In the amphibian Pleurodeles waltl, steroid hormones play a key role in sex differentiation. Since cadmium has been reported to block receptors of sex steroid hormones, we analyzed the effects of this heavy metal on Pleurodeles larvae gonadogenesis. At stage 42, larvae die in the presence of 10.9 μM Cd in the rearing tap water, with TL 50 of 46.3 h, but the concentration of 5.5 μM is tolerated for more than 60 days. When used at 5.5 μM cadmium accumulation measured by atomic absorption spectrophotometry (AAS) in total homogenates of larvae at stage 54 (after 77 days of exposure to the heavy metal) reached 58.1 μg/g of dry weight. At stage 54, we did not detect inhibitory effects on gonadogenesis in larvae reared in the presence of 5.5 μM Cd since stage 42. When the exposure to 5.5 μM Cd was lengthened after stage 54, metamorphosis was delayed and could not be completed. When larvae were exposed to 10.9 μM Cd from stage 54, metamorphosis did not occur and gonad development was stopped. Our study demonstrates a lack of a direct effect of cadmium on sex determination-differentiation but a strong inhibitory effect on metamorphosis, which impairs further gonadal development.