title: Implications of genomic signatures in the differential vulnerability to fetal alcohol exposure in C57BL/6 and DBA/2 mice.
abstract: Maternal alcohol consumption inflicts a multitude of phenotypic consequences that range from undetectable changes to severe dysmorphology. Using tightly controlled murine studies that deliver precise amounts of alcohol at discrete developmental stages, our group and other labs demonstrated in prior studies that the C57BL/6 and DBA/2 inbred mouse strains display differential susceptibility to the teratogenic effects of alcohol. Since the phenotypic diversity extends beyond the amount, dosage and timing of alcohol exposure, it is likely that an individual's genetic background contributes to the phenotypic spectrum. To identify the genomic signatures associated with these observed differences in alcohol-induced dysmorphology, we conducted a microarray-based transcriptome study that also interrogated the genomic signatures between these two lines based on genetic background and alcohol exposure. This approach is called a gene x environment (GxE) analysis; one example of a GxE interaction would be a gene whose expression level increases in C57BL/6, but decreases in DBA/2 embryos, following alcohol exposure. We identified 35 candidate genes exhibiting GxE interactions. To identify cis-acting factors that mediated these interactions, we interrogated the proximal promoters of these 35 candidates and found 241 single nucleotide variants (SNVs) in 16 promoters. Further investigation indicated that 186 SNVs (15 promoters) are predicted to alter transcription factor binding. In addition, 62 SNVs created, removed or altered the placement of a CpG dinucleotide in 13 of the proximal promoters, 53 of which overlapped putative transcription factor binding sites. These 53 SNVs are also our top candidates for future studies aimed at examining the effects of alcohol on epigenetic gene regulation.
authors: Department of Animal Sciences, Purdue University West Lafayette, IN, USA.
authors: Amy C
authors: AC
authors: Lossie
authors: Department of Animal Sciences, Purdue University West Lafayette, IN, USA ; Department of Medicine, Indiana University School of Medicine Indianapolis, IN, USA.
authors: William M
authors: WM
authors: Muir
authors: Department of Anatomy and Cell Biology, Indiana University School of Medicine Indianapolis, IN, USA.
authors: Chiao-Ling
authors: CL
authors: Lo
authors: Department of Anatomy and Cell Biology, Indiana University School of Medicine Indianapolis, IN, USA.
authors: Floyd
authors: F
authors: Timm
authors: Department of Molecular and Medical Genetics, Indiana University School of Medicine Indianapolis, IN, USA.
authors: Yunlong
authors: Y
authors: Liu
authors: Department of Anatomy and Cell Biology, Indiana University School of Medicine Indianapolis, IN, USA.
authors: Whitney
authors: W
authors: Gray
authors: Department of Anatomy and Cell Biology, Indiana University School of Medicine Indianapolis, IN, USA ; Stark Neuroscience Research Institute, Indiana University School of Medicine Indianapolis, IN, USA.
authors: Feng C
authors: FC
authors: Zhou
keywords: epigenetics; fetal alcohol syndrome; gene expression; gene x environment interactions; genetic association; genomics; next generation sequencing