Molecular impact of juvenile hormone agonists on neonatal Daphnia magna

Kenji Toyota, Yasuhiko Kato, Hitoshi Miyakawa, Ryohei Yatsu, Takeshi Mizutani, Yukiko Ogino, Shinichi Miyagawa, Hajime Watanabe, Hiroyo Nishide, Ikuo Uchiyama, Norihisa Tatarazako, Taisen Iguchi

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21 Citations (Scopus)

Abstract

Daphnia magna has been used extensively to evaluate organism- and population-level responses to pollutants in acute toxicity and reproductive toxicity tests. We have previously reported that exposure to juvenile hormone (JH) agonists results in a reduction of reproductive function and production of male offspring in a cyclic parthenogenesis, D. magna. Recent advances in molecular techniques have provided tools to understand better the responses to pollutants in aquatic organisms, including D. magna. DNA microarray was used to evaluate gene expression profiles of neonatal daphnids exposed to JH agonists: methoprene (125, 250 and 500 ppb), fenoxycarb (0.5, 1 and 2 ppb) and epofenonane (50, 100 and 200 ppb). Exposure to these JH analogs resulted in chemical-specific patterns of gene expression. The heat map analyses based on hierarchical clustering revealed a similar pattern between treatments with a high dose of methoprene and with epofenonane. In contrast, treatment with low to middle doses of methoprene resulted in similar profiles to fenoxycarb treatments. Hemoglobin and JH epoxide hydrolase genes were clustered as JH-responsive genes. These data suggest that fenoxycarb has high activity as a JH agonist, methoprene shows high toxicity and epofenonane works through a different mechanism compared with other JH analogs, agreeing with data of previously reported toxicity tests. In conclusion, D. magna DNA microarray is useful for the classification of JH analogs and identification of JH-responsive genes.

Original languageEnglish
Pages (from-to)537-544
Number of pages8
JournalJournal of Applied Toxicology
Volume34
Issue number5
DOIs
Publication statusPublished - 1 Jan 2014

Keywords

  • Daphnia magna
  • Gene expression
  • Juvenile hormone agonists
  • Juvenile hormone-responsive gene
  • Microarray

Cite this

Toyota, K., Kato, Y., Miyakawa, H., Yatsu, R., Mizutani, T., Ogino, Y., Miyagawa, S., Watanabe, H., Nishide, H., Uchiyama, I., Tatarazako, N., & Iguchi, T. (2014). Molecular impact of juvenile hormone agonists on neonatal Daphnia magna. Journal of Applied Toxicology, 34(5), 537-544. https://doi.org/10.1002/jat.2922