Juvenile hormone agonists affect the occurrence of male Daphnia

Tatarazako, Norihisa; Oda, Shigeto; Watanabe, Hidenobu; Morita, Masatoshi; Iguchi, Taisen

doi:10.1016/s0045-6535(03)00761-6

Cited by 180 publications

(183 citation statements)

References 13 publications

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“…The environmental signal to produce male offspring is transduced, within the organism, by a terpenoid signaling pathway ( Fig.·6; Olmstead and LeBlanc, 2002;Tatarazako et al, 2003). The results of the present study demonstrate that hemoglobin levels are regulated by this same terpenoid signaling pathway in addition to the hypoxia/HIF signaling pathway.…”

Section: Discussionmentioning

confidence: 51%

Stress signaling: coregulation of hemoglobin and male sex determination through a terpenoid signaling pathway in a crustacean

Rider

Gorr

Olmstead

et al. 2005

Journal of Experimental Biology

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Environmental signals can activate neuro-endocrine cascades that regulate various physiological processes. In the present study, we demonstrate that two responses to environmental stress signaling in the crustacean Daphnia magna -hemoglobin accumulation and male offspring production -are co-elevated by the crustacean terpenoid hormone methyl farnesoate and several synthetic analogs. Potency of the hormones with respect to the induction of both hemoglobin and male offspring was highly correlated, suggesting that both processes are regulated by the same terpenoid signaling pathway. Six clones of the D. pulex/pulicaria species complex that were previously characterized as unable to produce male offspring and five clones that were capable of producing males were evaluated for both hemoglobin induction and male offspring production in response to methyl farnesoate. Four of the five male-producing clones produced both hemoglobin and male offspring in response to the hormone. Five of the six non-male-producing clones produced neither hemoglobin nor males in response to the hormone. These results provide additional evidence that both physiological processes are regulated by the same signaling pathway. Furthermore, the results indicate that the non-male-producing clones are largely defective in some methyl farnesoate signaling component, downstream from methyl farnesoate synthesis but upstream from the genes regulated by the hormone. A likely candidate for the site of the defect is the methyl farnesoate receptor. As a consequence of this defect, non-male-producing clones have lost their responsiveness to environmental signals that are transduced by this endocrine pathway. This defect in signaling would be likely to enhance population growth in stable environments due to the elimination of males from the population, assuming that other processes critical to population growth are not also compromised by this defect.

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Section: Discussionmentioning

confidence: 51%

Stress signaling: coregulation of hemoglobin and male sex determination through a terpenoid signaling pathway in a crustacean

Rider

Gorr

Olmstead

et al. 2005

Journal of Experimental Biology

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“…The Ec affects male progeny production and chemicals related to JH increase male production in Daphnia magna and other daphnids (Peterson et al 2001, Tatarazako et al 2003. These findings suggest that sex determination in Daphnia is closely tied to hormonal systems.…”

Section: Introductionmentioning

confidence: 91%

“…The D. magna strain (NIES clone) was obtained from the National Institute for Environmental Studies (NIES; Tsukuba, Japan; Tatarazako et al 2003). The strain originated at the Environmental Protection Agency USA and was maintained for more than 10 years at NIES.…”

Section: Daphnia Strain and Culture Conditionsmentioning

confidence: 99%

Cloning and characterization of the ecdysone receptor and ultraspiracle protein from the water flea Daphnia magna

Kato¹,

Kobayashi²,

Oda³

et al. 2007

Journal of Endocrinology

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cDNAs encoding the ecdysone receptor (EcR) and ultraspiracle (USP) protein were cloned from the water flea Daphnia magna (Crustacea: Cladocera). The deduced EcR and USP amino acid sequences showed a high degree of homology to those of other crustaceans as well as insects. We isolated three isoforms of EcR that differ in the A/B domain. Quantitative PCR analysis indicated differing temporal expression patterns of the EcR isoforms during the molting period and demonstrated that the expression of one subtype correlated well with the timing of molt. Using cDNAs encoding EcR and USP, we constructed a Daphnia EcR/USP reporter based on a two-hybrid system.The gene fusions encoded the EcR ligand-binding domain (LBD) fused to the Gal4 DNA-binding domain, and the USP-LBD fused to the Vp16 activation domain. These chimeric genes were transfected with a luciferase reporter gene. Dose-dependent activation of the reporter gene could be observed when transfectants were exposed to Ec and other chemicals known to have Ec-like activities. This two-hybrid system may represent a useful reporter system for further examination of hormonal and chemical effects on Daphnia at the molecular level.

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“…Other JH analogs (JHAs) in addition to MF have been shown to induce male production in Daphnia. The insecticides pyriproxyfen, fenoxycarb and methoprene cause male broods (Tatarazako et al, 2003), with orders of magnitude greater potency than MF for pyriproxyfen and fenoxycarb. Interestingly, all of these compounds also induce Hb production in Daphnia (Rider et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

Ecological genomics in Daphnia: stress responses and environmental sex determination

2007

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Ecological genomics is the study of adaptation of natural populations to their environment, and therefore seeks to link organism and population level processes through an understanding of genome organization and function. The planktonic microcrustacean Daphnia, which has long been an important system for ecology, is now being used as a genomic model as well. Here we review recent progress in selected areas of Daphnia genomics research. Production of parthenogenetic male offspring occurs through environmental cues, which clearly involves endocrine regulation and has also been studied as a toxicological response to juvenoid hormone analog insecticides. Recent progress has uncovered a putative juvenoid cis-response element, which together with microarray analysis will stimulate further research into nuclear hormone receptors and their associated transcriptional regulatory networks. Ecotoxicological studies indicate that mRNA profiling is a sensitive and specific research tool with promising applications in environmental monitoring and for uncovering conserved cellular processes. Rapid progress is expected to continue in these and other areas, as genomic tools for Daphnia become widely available to investigators.

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Juvenile hormone agonists affect the occurrence of male Daphnia

Cited by 180 publications

References 13 publications

Stress signaling: coregulation of hemoglobin and male sex determination through a terpenoid signaling pathway in a crustacean

Stress signaling: coregulation of hemoglobin and male sex determination through a terpenoid signaling pathway in a crustacean

Cloning and characterization of the ecdysone receptor and ultraspiracle protein from the water flea Daphnia magna

Ecological genomics in Daphnia: stress responses and environmental sex determination

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