The time- and age-dependent effects of the juvenile hormone analog pesticide, pyriproxyfen on Daphnia magna reproduction

Abstract

Pyriproxyfen is an insecticidal juvenile hormone analog that perturbs insect and tick development. Pyriproxyfen also alters parthenogenic reproduction in non-target cladoceran species as it induces male production that can lead to a decrease in fecundity, a reduction in population density, and subsequent ecological effects. In this study, we investigate the impacts of pyriproxyfen on Daphnia magna reproduction using a series of male production screening assays. These assays demonstrate that pyriproxyfen increases male production in a concentration-dependent fashion with an EC50 of 156 pM (50.24 ng L-1); a concentration considered environmentally relevant. Furthermore, pyriproxyfen decreases overall fecundity at all ages tested (7, 14, 21-d old female parthenogenic daphnids). Juvenile (3-d old) and reproductively mature (10-d old) female daphnids were also exposed to 155 pM pyriproxyfen for 2 – 12 d and reproduction measured for 16 d to compare the effects of short-term and prolonged exposures, and determine the potential for recovery. Results indicate that longer pyriproxyfen exposures (8–12 d) extend male production and decrease reproduction; however, daphnids exposed for only 2–4 d recover and produce a relatively normal abundance of neonates. In addition, juvenile daphnids are also very sensitive to pyriproxyfen, but the primary effect on juvenile daphnids is reduced reproduction and protracted development not male production. Taken together, continued use of pyriproxyfen around water bodies needs due caution because of its potential adverse effects with significant developmental delays and male production compounded by prolonged exposure.

De Novo Transcriptome Assembly and Sex-Biased Gene Expression in the Cyclical ParthenogeneticDaphnia galeata

“…Nevertheless, some differences between MF-induced and naturally produced males have been described. For example, MF-induced males show delayed development and decreased fecundity (Olmstead and LeBlanc 2002; Tatarazako et al 2003; Ginjupalli and Baldwin 2013). We could also observe this in a preliminary study on our own D. galeata populations.…”

“…A recent study showed that the NMDA receptor seems to be involved in signaling upstream of MF and may be a sensor of environmental stimuli (LeBlanc and Medlock 2015; Toyota, Miyakawa, Yamaguchi, et al 2015). In addition, exogenous treatment with MF and other JH III analogs induces male production in a dose-dependent manner (Olmstead and LeBlanc 2002; Tatarazako et al 2003; Ginjupalli and Baldwin 2013). Some of these JH III analogs are common insecticides that reach freshwater systems with rain washout, where they can disturb the natural cycles of sexual and asexual reproduction in Daphnia .…”

“…It is not clear, however, how exogenous MF-induced male production differs from natural male production. There is evidence indicating that exogenously induced males are worse at fertilizing resting eggs than naturally produced males and that JH III homologs reduce fertility and life span in general (Tatarazako et al 2003; Ginjupalli and Baldwin 2013; LeBlanc et al 2013). Thus, it seems that MF treatment can have an effect that differs from natural sexual reproduction.…”

Digging Deeper Into the Pyriproxyfen-Response of the Amphipod Gammarus fossarum With a Next-Generation Ultra-High-Field Orbitrap Analyser: New Perspectives for Environmental Toxicoproteomics

“…The juvenoid analog pyriproxyfen is used in agriculture as a growth regulator to inhibit the larval development and maturation of many arachnid and insect pests: ticks, mosquitos, ants, houseflies, and fleas (Sullivan and Goh, 2008). This molecule also affects crustaceans, inducing morphological abnormalities and limiting growth rates in decapods (LeBlanc, 2007), decreasing female fecundity and altering the sex ratio in branchiopods (Olmstead and LeBlanc, 2003;Ginjupalli and Baldwin, 2013), and reducing sperm production in amphipods (Trapp et al, 2015).…”

Effects of Pyriproxyfen on Viability and Increase of Intracellular Lipids in HepG2 Cell Line

“…PPF is a juvenile hormone analogue (JHA) that interrupts normal development and metamorphosis of targeted mosquitoes [11]. It also alters parthenogenic reproduction in non-target cladoceran species as it induces male production that can lead to a decrease in fecundity, a reduction in population density, and subsequent ecological effects [12]. Highly potent in terms of activity and specificity, PPF degrades rapidly in soil under aerobic conditions, with a half-life of 6.4-36 days and it disappeared from aerobic lake water-sediment systems with half-lives ranging from 16 to 21 days.…”