title: The larvicide pyriproxyfen blamed during the Zika virus outbreak does not cause microcephaly in zebrafish embryos.
abstract: Although the zika virus (ZIKV) has now been strongly correlated with emerging cases of microcephaly in the Americas, suspicions have been raised regarding the use of pyriproxyfen, a larvicide that prevents mosquito development, in drinking water. The effects of this compound on neurodevelopment have not yet been addressed specifically in vertebrates. As a result, we aimed at addressing the effects, if any, of pyriproxyfen on neurodevelopment in the zebrafish embryo as a vertebrate model. Using zebrafish transgenic lines expressing GFP in different cell populations (elavl3 in newborn neurons, gfap and nestin in neural stem cells), we focused on the analysis of whole embryonic brain volume after confocal 3D-reconstruction and the quantification of purified neural stem cells during early neurodevelopment by FACS-cell sorting from whole in vivo embryos. Interestingly, though lethal at very high doses, pyriproxyfen did not cause brain malformation nor any significant changes in the number of observed stem cells in the developing central nervous system. Our data indicate that pyriproxyfen does not affect central nervous system development in zebrafish, suggesting that this larvicide on its own, may not be correlated with the increase in microcephaly cases reported recently.
authors.affiliation: Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montréal, QC, Canada.
authors.forename: Stefania
authors.initials: S
authors.lastname: Dzieciolowska
authors.affiliation: Drug Discovery Platform, Research Institute of the McGill University Health Center, Montréal, QC, Canada.
authors.forename: Anne-Laure
authors.initials: AL
authors.lastname: Larroque
authors.affiliation: Drug Discovery Platform, Research Institute of the McGill University Health Center, Montréal, QC, Canada.
authors.forename: Elizabeth-Ann
authors.initials: EA
authors.lastname: Kranjec
authors.affiliation: Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montréal, QC, Canada.|DanioDesign Inc., Montréal, QC, Canada.
authors.forename: Pierre
authors.initials: P
authors.lastname: Drapeau
authors.affiliation: Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montréal, QC, Canada.|DanioDesign Inc., Montréal, QC, Canada.
authors.forename: Eric
authors.initials: E
authors.lastname: Samarut
mesh_terms: D000818:Animals; D001921:Brain / Q000196:embryology*; D002452:Cell Count; D004195:Disease Models, Animal; D004196:Disease Outbreaks; D007306:Insecticides / Q000633:toxicity*; D008831:Microcephaly / Q000139:chemically induced*; D058953:Neural Stem Cells / Q000187:drug effects / Q000502:physiology; D011725:Pyridines / Q000633:toxicity*; D015027:Zebrafish / Q000196:embryology
chemical_list: D007306:Insecticides; D011725:Pyridines; C055613:pyriproxyfen