title: Large-scale analysis of acute ethanol exposure in zebrafish development: a critical time window and resilience.
abstract: BACKGROUND
  In humans, ethanol exposure during pregnancy causes a spectrum of developmental defects (fetal alcohol syndrome or FAS). Individuals vary in phenotypic expression. Zebrafish embryos develop FAS-like features after ethanol exposure. In this study, we ask whether stage-specific effects of ethanol can be identified in the zebrafish, and if so, whether they allow the pinpointing of sensitive developmental mechanisms. We have therefore conducted the first large-scale (>1500 embryos) analysis of acute, stage-specific drug effects on zebrafish development, with a large panel of readouts.
  
  
  RESULTS
  Zebrafish embryos were raised in 96-well plates. Range-finding indicated that 10% ethanol for 1 h was suitable for an acute exposure regime. High-resolution magic-angle spinning proton magnetic resonance spectroscopy showed that this produced a transient pulse of 0.86% concentration of ethanol in the embryo within the chorion. Survivors at 5 days postfertilisation were analysed. Phenotypes ranged from normal (resilient) to severely malformed. Ethanol exposure at early stages caused high mortality (≥88%). At later stages of exposure, mortality declined and malformations developed. Pharyngeal arch hypoplasia and behavioral impairment were most common after prim-6 and prim-16 exposure. By contrast, microphthalmia and growth retardation were stage-independent.
  
  
  CONCLUSIONS
  Our findings show that some ethanol effects are strongly stage-dependent. The phenotypes mimic key aspects of FAS including craniofacial abnormality, microphthalmia, growth retardation and behavioral impairment. We also identify a critical time window (prim-6 and prim-16) for ethanol sensitivity. Finally, our identification of a wide phenotypic spectrum is reminiscent of human FAS, and may provide a useful model for studying disease resilience.
authors.affiliation: Institute of Biology, Leiden University, Sylvius Laboratory, Leiden, The Netherlands.
authors.forename: Shaukat
authors.initials: S
authors.lastname: Ali
authors.forename: Danielle L
authors.initials: DL
authors.lastname: Champagne
authors.forename: Alia
authors.initials: A
authors.lastname: Alia
authors.forename: Michael K
authors.initials: MK
authors.lastname: Richardson
mesh_terms: D000818:Animals; D000431:Ethanol / Q000008:administration & dosage / Q000633:toxicity*; D005260:Female; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D013723:Teratogens / Q000633:toxicity*; D013997:Time Factors; D015027:Zebrafish / Q000196:embryology*
chemical_list: D013723:Teratogens; D000431:Ethanol