Bombyx mori was used as a model to evaluate the reproductive toxicity of NaF in insects. Significant reduction in cocoon quality, survival rate, fecundity, and hatchability were observed upon NaF treatment groups. Fluoride determination indicated that F- has a cumulative effect on the gonad of silkworm. High-performance liquid chromatography revealed that the testosterone content of males was decreased in NaF-treated groups, and enzyme-linked immunosorbent assay showed that the estradiol content was decreased in NaF-treated females. Ultrastructural observation of testicles of silkworm larvae revealed mitochondrial turgescence, endoplasmic reticulum destruction, the appearance of vacuoles and lysosomes, and apoptosis and necrosis of cells in NaF-treated groups. Altered tail length and tail DNA content in Comet assays further confirmed DNA damage in NaF-treated larvae. We demonstrated reproductive toxicity of fluoride toward silkworm at physiological and biochemical levels, and the results provide a theoretical basis for revealing the reproductive toxicity of fluoride in terrestrial insects.
Keywords: DNA damage; Fluoride; Reproductive toxicity; Silkworm; Testis; Ultrastructure.
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