Project description:Fyn kinase has been implicated in multiple behavioral responses to ethanol and in the regulation of myelin gene expression. Here we tested whether Fyn kinase modulated basal or ethanol-responsive expression of genes regulated by acute ethanol in brain regions of the mesolimbocortical dopamine pathway. Using expression profiling, we sought to define Fyn-dependent gene networks underlying ethanol behavioral traits; with emphasis on ethanol-induced loss of righting reflex (LORR) due to the reproducible association of Fyn kinase genotype with this behavioral phenotype (Miyakawa et al., 1997, Boehm et al., 2003, Yaka et al., 2003, Boehm et al., 2004b). Our expression profiling and bioinformatics results suggest multiple Fyn-related mechanisms, especially those affecting a network of myelin-related gene expression within the medial PFC, as contributing to the sedative-hypnotic properties of ethanol. Variation in the expression of these Fyn-dependent gene networks may be critical molecular endophenotypes affecting the behavioral level of response to acute ethanol, and subsequently, the long-term risk for alcohol use disorders. Adult male control (B6129SF2/J) and Fyn-kinase null (B6;129S7-Fyntm1Sor/J) mice were treated with saline or ethanol (3.0 g/kg x 4 hours) and brain regions harvested by microdissection for total RNA expression profiling by Affymetrix microarrays. Samples were randomly assigned to batch groups prior to total RNA extraction, cRNA synthesis and hybridization. Each microarray represents a pooling of 3 animals and 3 arrays were analyzed per treatment group for a total of 12 arrays per brain region. Statistical and bioinformatics analysis was used to identify Fyn-dependent effects on basal and ethanol-responsive gene expression, with a particular focus on myelin-related gene expression. This series of samples includes medial prefrontal cortex (PFC).
Project description:Fyn kinase has been implicated in multiple behavioral responses to ethanol and in the regulation of myelin gene expression. Here we tested whether Fyn kinase modulated basal or ethanol-responsive expression of genes regulated by acute ethanol in brain regions of the mesolimbocortical dopamine pathway. Using expression profiling, we sought to define Fyn-dependent gene networks underlying ethanol behavioral traits; with emphasis on ethanol-induced loss of righting reflex (LORR) due to the reproducible association of Fyn kinase genotype with this behavioral phenotype (Miyakawa et al., 1997, Boehm et al., 2003, Yaka et al., 2003, Boehm et al., 2004b). Our expression profiling and bioinformatics results suggest multiple Fyn-related mechanisms, especially those affecting a network of myelin-related gene expression within the medial PFC, as contributing to the sedative-hypnotic properties of ethanol. Variation in the expression of these Fyn-dependent gene networks may be critical molecular endophenotypes affecting the behavioral level of response to acute ethanol, and subsequently, the long-term risk for alcohol use disorders.
Project description:In order to elucidate the molecular mechanisms underlying individual variation in sensitivity to ethanol we profiled the prefrontal cortex transcriptomes of two inbred strains that exhibit divergent responses to acute ethanol, the C57BL6/J (B6) and DBA/2J (D2) strains, as well as 27 members of the BXD recombinant inbred panel, which was derived from a B6 x D2 cross. With this dataset we were able to identify several gene co-expression networks that were robustly altered by acute ethanol across the BXD panel. These ethanol-responsive gene-enriched networks were heavily populated by genes regulating synaptic transmission and neuroplasticity, and showed strong genetic linkage to discreet chromosomal loci. Network-based measurements of node importance identified several hub genes as established regulators of ethanol response phenotypes, while other hubs represent novel candidate modulators of ethanol responses. Animals were injected intraperitoneally (IP) with saline or 1.8 g/kg of ethanol. As part of a parallel study of ethanol induced anxiolysis, all mice underwent behavioral testing that included 15 minutes of restraint in a 50 mL conical tube followed by 10 minutes in a light-dark chamber. Mice were killed by cervical dislocation four hours following IP injection. Immediately thereafter, brains were extracted and chilled for 1 minute in iced phosphate buffer before being microdissected into 8 constituent regions, including the medial prefrontal cortex. Samples were randomly assigned to batch groups prior to total RNA extraction, cRNA synthesis and hybridization. Each microarray represent a pooling of 4-5 animals.
Project description:In order to elucidate the molecular mechanisms underlying individual variation in sensitivity to ethanol we profiled the prefrontal cortex transcriptomes of two inbred strains that exhibit divergent responses to acute ethanol, the C57BL6/J (B6) and DBA/2J (D2) strains, as well as 27 members of the BXD recombinant inbred panel, which was derived from a B6 x D2 cross. With this dataset we were able to identify several gene co-expression networks that were robustly altered by acute ethanol across the BXD panel. These ethanol-responsive gene-enriched networks were heavily populated by genes regulating synaptic transmission and neuroplasticity, and showed strong genetic linkage to discreet chromosomal loci. Network-based measurements of node importance identified several hub genes as established regulators of ethanol response phenotypes, while other hubs represent novel candidate modulators of ethanol responses.
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.
Project description:Here, we identify persistent and substantial variation in ethanol drinking behavior within an inbred mouse strain and utilize this model to identify gene networks influencing such non-genetic variation in ethanol intake. C57BL/6NCrl mice showed persistent inter-individual variation of ethanol intake in a two-bottle choice paradigm over a three week period, ranging from less than 1 g/kg to over 14 g/kg ethanol in an 18h interval. Whole genome microarray expression analysis in nucleus accumbens, prefrontal cortex and ventral tegmental area of individual animals identified gene expression patterns correlated with ethanol intake. Results included several gene networks previously implicated in ethanol behaviors, such as glutamate signaling, BDNF and genes involved in synaptic vesicle function. Additionally, genes functioning in epigenetic chromatin or DNA modifications such as acetylation and/or methylation also had expression patterns correlated with ethanol intake. Our results thus implicate specific brain regional gene networks, including chromatin modification factors, as potentially important mechanisms underlying individual variation in ethanol intake. Voluntary two-bottle choice drinking was performed as described previously (Khisti et al. 2006). Briefly, two bottles containing 10%(w/v) ethanol (Aaper Alcohol and Chemical Co. Shelbyville, KY) or tap water were placed into the home cage at the beginning of the dark cycle. Tube position was varied every two days (L, L, R, R). Drinking sessions lasted 18 hours/day followed by 6 hours access to water only. Mice had four consecutive drinking sessions followed by four days of abstinence repeated four times to give 16 total drinking sessions. Three brain regions were harvested 6 days after the last drinking session: prefrontal cortex (PFC), nucleus accumbens (NAc) and ventral tegmental area (VTA) as previously described (Kerns et al. 2005). Labeled cRNA from individual animals (n=19) was hybridized to a single microarray for each brain region (n=58 total microarrays).
Project description:Persistent changes in brain gene expression are hypothesized to underlie thealtered neural signaling producing abusive consumption in AUD. To identify brain regional gene expression networks contributing to progressive ethanol consumption, we performed microarray and scale-free network analysis of expression responses in a C57BL/6J mouse model utilizing chronic intermittent ethanol by vapor chamber (CIE) in combination with limited access oral ethanol consumption. The interaction of CIE and oral consumption was studied with Affymetrix microarrays. Gene expression was studied in medial prefrontal cortex, nucleus accumbens, hippocampus, bed nucleus of the stria terminalis, and central nucleus of the amygdala. Brain region expression networks were analyzed for ethanol-responsive gene expression, correlation with ethanol consumption and functional content using extensive bioinformatics studies.