Tolerance of the Nematode Caenorhabditis elegans to pH, Salinity, and Hardness in Aquatic Media

Kohra

Iguchi

et al. 2004

Toxicity studies using the nematode Caenorhabditis elegans (C. elegans) as a model organism have shown that perfluoro organic compounds have sub-lethal toxicity at the 10 pM-100 nM range on multi-generation assays. We examined the acute lethal toxicity and multi-generational sublethal toxicity (fecundity and reproduction) of perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA) and salts of perfluoro-1-octansulfonic acid (PFOS) using 1.7% agar Nematode Growth Medium (NGM) plates. The fluorine compounds affected the fecundity of C. elegans at concentrations 10 5 -to 10 8 -fold lower than the median effective concentrations (EC 50 ). In particular, worm abundance during the first generation did not differ significantly from controls, while in contrast, the number of worms in the fourth generation at 10 pM PFOStetraethylammonium (TEA) decreased significantly to about 50% of control (p < 0.01) and the number of eggs and worms in the fourth generation at 1 nM PFNA decreased significantly to about 30% of control (p < 0.01). However, no dose-response relationship was observed in this study. We confirmed that perfluoro organic compounds strongly disrupt fecundity in C. elegans.

Section: Introductionmentioning

confidence: 99%

Effects of Perfluoro Organic Compound Toxicity on Nematode Caenorhabditis elegans Fecundity

Kohra

Iguchi

et al. 2004

“…9) Subsequently, many researchers have used it for aquatic, sediment, and soil toxicity tests. [10][11][12][13] Power and Pomerai developed a transgenic nematode, carrying a stress-inducible β-galactosidase reporter, for a toxicity test in soil biomonitoring. 14) More recently, we reported that treatment of C. elegans hermaphrodites with estradiol or certain EDCs increases the expression level of vitellogenin (VTG), the egg yolk protein precursor synthesized by female oviparous animals.…”

Section: Introductionmentioning

confidence: 99%

Caenorhabditis elegans Responses to Specific Steroid Hormones.

Ura

Kawakami

et al. 2003

In this paper, Caenorhabditis elegans (C. elegans) is proposed as a model organism for studying chemical effects over multiple generations. We investigated whether C. elegans responds to vertebrate steroid hormones. We found that estrogenic steroids, especially estradiol (E2), have a cholesterol-like potency in supporting the reproduction of C. elegans. In contrast, testosterone (TS) and diethylstilbestrol (DES) did not display this potency. On the other hand, E2, TS and DES supressed the fecundity rate of C. elegans, when culture carried out with cholesterol. Moreover effect of TS accumulated over generation, in contrast to the other chemicals tested. These data suggested that with convenient biomarkers such as fecundity, C. elegans might be an effective model organism for studying chemical actions, including the disruption of reproduction.

“…3) Many studies have used C. elegans in assessments of acute and chronic chemical hazards, [4][5][6][7][8][9][10][11][12][13][14] and thus C. elegans serves as an efficient model for testing the effects of xenobiotic chemicals in vivo. Accordingly, we have established several laboratory-scale bioassay systems to evaluate the impact of various chemicals on C. elegans.…”

mentioning

confidence: 99%

A Multi-Generation Sublethal Assay of Phenols Using the Nematode Caenorhabditis elegans

Kohra

Iguchi

et al. 2003

The nematode Caenorhabditis elegans (C. elegans) was used for a multiple-generation toxicity bioassay of phenols. We examined the sublethal toxicity (fecundity and reproduction) of bisphenol A (BisA), 4-(1-adamantyl) phenol (Adp), and 4,4′-(1,3-adamantanediyl) diphenol (AdDP) over five generations using a Nematode Growth Medium (NGM) 1.7% agar plate. In the fourth generation, the phenols affected the fecundity rate of C. elegans at doses 100-to 10000-fold lower than the LC 50 s. In particular, at 1 nM BisA, the number of worms decreased significantly to about 50% of control (p < 0.05). A comparison of the number of viable worms and eggs suggested that the phenols exert hatching toxicity. In addition, individuals with an abnormality in the vulva, which could not ovulate, appeared on the phenol-containing plates. We confirmed that phenols disrupt reproduction in C. elegans and that the method using NGM agar plates facilitates multi-generational toxicity tests of chemicals that are poorly soluble in water.