Project description:In order to determine the imprinted transcription factor Zac1 targets, we overexpressed Zac1 in a neuroblastoma cell line and measured both the regulated expressed genes by Differential Gene Expressed analysis and Zac1 binding sites throughout the mouse genome by ChIP-seq. We have shown that Zac1 regulates and binds closed to many genes belonging to the Imprinted Gene Network.
Project description:In order to determine the imprinted transcription factor Zac1 targets, we overexpressed Zac1 in a neuroblastoma cell line and measured both the regulated expressed genes by Differential Gene Expressed analysis and Zac1 binding sites throughout the mouse genome by ChIP-seq. We have shown that Zac1 regulates and binds closed to many genes belonging to the Imprinted Gene Network.
Project description:In order to determine the imprinted transcription factor Zac1 targets, we overexpressed Zac1 in a mouse insulinoma cell line and measured the regulated expressed genes by RNA-seq. We have shown that Zac1 regulates many genes belonging to the Imprinted Gene Network, including genes coding for the extra-cellular matrix.
Project description:In order to determine the targets of the imprinted transcription factor Zac1, we compared wild type and Zac1-mutant MEFs and measured the differentially expressed genes by RNA-seq. Genes deregulated in the absence of Zac1 include genes belonging to the Imprinted Gene Network and genes coding for the extra-cellular matrix.
Project description:Genome-wide characterization of Zac1 target genes reveals its role as a broad regulator of the imprinted gene network including extracellular matrix genes.
Project description:Background and Aims Within the next decade, non-alcoholic fatty liver disease (NAFLD) is predicted to become the most prevalent cause of childhood liver failure in developed countries. Predisposition to juvenile NAFLD can be programmed during early life in response to maternal metabolic syndrome (MetS), but the underlying mechanisms are poorly understood. We hypothesized that imprinted genes, defined by expression from a single parental allele, play a key role in maternal MetS-induced NAFLD, due to their susceptibility to environmental stressors and their functions in liver homeostasis. We aimed to test this hypothesis and determine the critical periods of susceptibility to maternal MetS. Approach and Results We established a mouse model to compare the effects of MetS during prenatal and postnatal development on NAFLD. Postnatal but not prenatal MetS exposure is associated with histological, biochemical and molecular signatures of hepatic steatosis and fibrosis in juvenile mice. Using RNA-seq, we show that the Imprinted Gene Network (IGN), including its regulator Zac1, is up-regulated and over-represented among differentially expressed genes, consistent with a role in maternal MetS-induced NAFLD. In support of this, activation of the IGN in cultured hepatoma cells by over-expressing Zac1 is sufficient to induce signatures of profibrogenic transformation. Using chromatin immunoprecipitation, we demonstrate that Zac1 binds the TGF-β1 and COL6A2 promoters, forming a direct pathway between imprinted genes and well-characterized pathophysiological mechanisms of NAFLD. Finally, we show that hepatocyte-specific over-expression of Zac1 is sufficient to drive fibrosis in vivo. Conclusions Our findings identify a novel pathway linking maternal MetS exposure during postnatal development to the programming of juvenile NAFLD, and provide support for the hypothesis that imprinted genes play a central role in metabolic disease programming.
Project description:Background and Aims Within the next decade, non-alcoholic fatty liver disease (NAFLD) is predicted to become the most prevalent cause of childhood liver failure in developed countries. Predisposition to juvenile NAFLD can be programmed during early life in response to maternal metabolic syndrome (MetS), but the underlying mechanisms are poorly understood. We hypothesized that imprinted genes, defined by expression from a single parental allele, play a key role in maternal MetS-induced NAFLD, due to their susceptibility to environmental stressors and their functions in liver homeostasis. We aimed to test this hypothesis and determine the critical periods of susceptibility to maternal MetS. Approach and Results We established a mouse model to compare the effects of MetS during prenatal and postnatal development on NAFLD. Postnatal but not prenatal MetS exposure is associated with histological, biochemical and molecular signatures of hepatic steatosis and fibrosis in juvenile mice. Using RNA-seq, we show that the Imprinted Gene Network (IGN), including its regulator Zac1, is up-regulated and over-represented among differentially expressed genes, consistent with a role in maternal MetS-induced NAFLD. In support of this, activation of the IGN in cultured hepatoma cells by over-expressing Zac1 is sufficient to induce signatures of profibrogenic transformation. Using chromatin immunoprecipitation, we demonstrate that Zac1 binds the TGF-β1 and COL6A2 promoters, forming a direct pathway between imprinted genes and well-characterized pathophysiological mechanisms of NAFLD. Finally, we show that hepatocyte-specific over-expression of Zac1 is sufficient to drive fibrosis in vivo. Conclusions Our findings identify a novel pathway linking maternal MetS exposure during postnatal development to the programming of juvenile NAFLD, and provide support for the hypothesis that imprinted genes play a central role in metabolic disease programming.
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.