Fetal Alcohol Spectrum Disorders (FASD) refers to the complex and highly variable deleterious phenotypes caused by prenatal alcohol exposure. This variability is likely driven by the interaction of genetic and epigenetic factors. Despite the prevalence and devastating impact of FASD, little is known about how these factors interact in ethanol teratogenesis. Results from a genetic ?shelf? screen revealed vangl2, a member of the Wnt/planar cell polarity (PCP) pathway, as an ethanol-sensitive genetic locus. Untreated vangl2 mutants displayed a relatively intact craniofacial skeleton. Ethanol-exposed vangl2 heterozygotes and mutants, displayed cyclopean and midfacial defects characteristic of other vangl2 compound mutants that fail to separate the eye field. Sequence analysis suggests that the Wnt/PCP pathway is regulated by microRNAs commonly upregulated by ethanol. Preliminary loss-of-function and gain-of-function studies show that ethanol- sensitive miR-107 is necessary and sufficient to induce the ethanol phenotype in vangl2 mutants. The objective of this proposed research is to understand how microRNAs mediate susceptibility to ethanol teratogenesis. The first specific aim will characterize the interaction of miR-107 and the Wnt/PCP pathway using A) immunoblot analyses, B) microRNA reporter analyses, and C) in vivo time-lapse imaging of miR-107 and ethanol-responsive cell behaviors. The second specific aim will utilize a bioinformatics approach to understand ethanol teratogenesis using A) miR-Seq, and B) RNA-Seq from unexposed and ethanol-exposed zebrafish embryos. This proposed research will yield important insight necessary to advance understanding and treatment for FASD.
This purpose of this research proposal is to gain an understanding of how genetic and epigenetic factors interact with environmental ethanol exposure. Experiments will examine how an ethanol-sensitive microRNA attenuates the Wnt/Planar Cell Polarity pathway, leading to midfacial defects commonly seen among children born with Fetal Alcohol Spectrum Disorders. Furthermore, results obtained from an unbiased RNA sequencing approach, will elucidate other sensitizing microRNAs and genetic pathways, to inform us of the etiology of this prevalent disease.
