Project description:Whereas cloning mammals by direct somatic cell nuclear transfer has been successful using a wide range of donor cell types, neurons from adult brain remain “unclonable” for unknown reasons. Here we examined whether neurons from adult mice could be cloned, using a combination of two epigenetic approaches. First, we used a specific antibody to discover cell types with reduced amounts of a repressive histone mark - dimethylated histone H3 lysine 9 (H3K9me2) - and identified CA1 pyramidal cells in the hippocampus and Purkinje cells in the cerebellum as candidates. Second, reconstructed embryos were treated with trichostatin A (TSA), a potent histone deacetylase inhibitor. Using CA1 cells, cloned offspring were obtained at high rates, reaching 10.2% and 4.6% (per embryos transferred) for male and female donors, respectively. Cerebellar Purkinje cell nuclei were too large to maintain their genetic integrity during nuclear transfer, leading to developmental arrest of embryos. However, gene expression analysis using cloned blastocysts corroborated a high rate of genomic reprogrammability of CA1 pyramidal and Purkinje cells. Neurons from the hippocampal dentate gyrus and cerebral cortex, which had higher amounts of H3K9me2, could also be used for producing cloned offspring, but the efficiencies were low. A more thorough analysis revealed that TSA treatment was essential for cloning adult neuronal cells. This study demonstrated for the first time that adult neurons could be cloned by nuclear transfer. Furthermore, our data imply that reduced amounts of H3K9me2 and increased histone acetylation appear to act synergistically to improve the development of cloned embryos.
Project description:Whereas cloning mammals by direct somatic cell nuclear transfer has been successful using a wide range of donor cell types, neurons from adult brain remain M-bM-^@M-^\unclonableM-bM-^@M-^] for unknown reasons. Here we examined whether neurons from adult mice could be cloned, using a combination of two epigenetic approaches. First, we used a specific antibody to discover cell types with reduced amounts of a repressive histone mark - dimethylated histone H3 lysine 9 (H3K9me2) - and identified CA1 pyramidal cells in the hippocampus and Purkinje cells in the cerebellum as candidates. Second, reconstructed embryos were treated with trichostatin A (TSA), a potent histone deacetylase inhibitor. Using CA1 cells, cloned offspring were obtained at high rates, reaching 10.2% and 4.6% (per embryos transferred) for male and female donors, respectively. Cerebellar Purkinje cell nuclei were too large to maintain their genetic integrity during nuclear transfer, leading to developmental arrest of embryos. However, gene expression analysis using cloned blastocysts corroborated a high rate of genomic reprogrammability of CA1 pyramidal and Purkinje cells. Neurons from the hippocampal dentate gyrus and cerebral cortex, which had higher amounts of H3K9me2, could also be used for producing cloned offspring, but the efficiencies were low. A more thorough analysis revealed that TSA treatment was essential for cloning adult neuronal cells. This study demonstrated for the first time that adult neurons could be cloned by nuclear transfer. Furthermore, our data imply that reduced amounts of H3K9me2 and increased histone acetylation appear to act synergistically to improve the development of cloned embryos. Comparative gene expression analyses using blastocysts of cloned embryos were performed by microarray. Cloned embryos were produced with three different types of donor cells (neonatal Sertoli cells, CA1 pyramidal cells and Purkinje cells) and all cloned embryos were treated with Trichostatin A (TSA). Each embryos were cultured for 96 h and blastocysts derived from each donor cell types were subjected to gene expression microarray. For comparison of gene expression, the data sets of control sex- and genotype-matched embryos produced by in vitro fertilization and SCNT-derived blastocysts from cumulus cells treated with TSA from our previous paper (Inoue K. et al. Science 2010) were also used.
Project description:We collected whole genome testis expression data from hybrid zone mice. We integrated GWAS mapping of testis expression traits and low testis weight to gain insight into the genetic basis of hybrid male sterility. Gene expression was measured in whole testis from males aged 62-86 days. Samples include 190 first generation lab-bred male offspring of wild-caught mice from the Mus musculus musculus - M. m. domesticus hybrid zone.
Project description:PURPOSE: To provide a detailed gene expression profile of the normal postnatal mouse cornea. METHODS: Serial analysis of gene expression (SAGE) was performed on postnatal day (PN)9 and adult mouse (6 week) total corneas. The expression of selected genes was analyzed by in situ hybridization. RESULTS: A total of 64,272 PN9 and 62,206 adult tags were sequenced. Mouse corneal transcriptomes are composed of at least 19,544 and 18,509 unique mRNAs, respectively. One third of the unique tags were expressed at both stages, whereas a third was identified exclusively in PN9 or adult corneas. Three hundred thirty-four PN9 and 339 adult tags were enriched more than fivefold over other published nonocular libraries. Abundant transcripts were associated with metabolic functions, redox activities, and barrier integrity. Three members of the Ly-6/uPAR family whose functions are unknown in the cornea constitute more than 1% of the total mRNA. Aquaporin 5, epithelial membrane protein and glutathione-S-transferase (GST) omega-1, and GST alpha-4 mRNAs were preferentially expressed in distinct corneal epithelial layers, providing new markers for stratification. More than 200 tags were differentially expressed, of which 25 mediate transcription. CONCLUSIONS: In addition to providing a detailed profile of expressed genes in the PN9 and mature mouse cornea, the present SAGE data demonstrate dynamic changes in gene expression after eye opening and provide new probes for exploring corneal epithelial cell stratification, development, and function and for exploring the intricate relationship between programmed and environmentally induced gene expression in the cornea. Keywords: other
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:We collected whole genome testis expression data from hybrid zone mice. We integrated GWAS mapping of testis expression traits and low testis weight to gain insight into the genetic basis of hybrid male sterility.
Project description:Production of viable and fertile mice have been reported by nuclear replacement, however, the reasons behind the frequent deformations among foetuses and progeny are not well understood. Activation and in vitro culture methods are also important. Origin of the nuclear donor cells affects success rates, and their survival in culture varies. It has been reported that offspring of nuclear replacement parental mice were normal and fertile. All epigenetic problems in the parents seem to be erased when cell nuclei go through the germ line. cDNA microarray analysis compared expression patterns of Dll1 ko versus Dll1 ko NT (NT = nuclear transfer) and wt versus wt NT of liver and spleen. The aim of this study was analysis of possible epigenetic effects by cloning in the offspring of the 3rd generation. If the 3rd generation cloned animals are indeed phenotypically equivalent to conventional transgenic mouse models then this would open the possibility to develop novel techniques of genetic engineering based on somatic gene targeting and nuclear replacement. four male animals of each cohort (Dll1 conventional transgenic mouse, Dll1 nuclear transfer mouse, wildtype, wildtye nuclear transfer mouse). Two technical replicates including a colour flip experiment. For each analysed organ (liver, spleen) eight experiments including four biological replicates. As reference RNA pools were used
Project description:BACKGROUND: Long terminal repeat (LTR) retrotransposons make up a large fraction of the typical mammalian genome. They comprise about 8% of the human genome and approximately 10% of the mouse genome. On account of their abundance, LTR retrotransposons are believed to hold major significance for genome structure and function. Recent advances in genome sequencing of a variety of model organisms has provided an unprecedented opportunity to evaluate better the diversity of LTR retrotransposons resident in eukaryotic genomes. RESULTS: Using a new data-mining program, LTR_STRUC, in conjunction with conventional techniques, we have mined the GenBank mouse (Mus musculus) database and the more complete Ensembl mouse dataset for LTR retrotransposons. We report here that the M. musculus genome contains at least 21 separate families of LTR retrotransposons; 13 of these families are described here for the first time. CONCLUSIONS: All families of mouse LTR retrotransposons are members of the gypsy-like superfamily of retroviral-like elements. Several different families of unrelated non-autonomous elements were identified, suggesting that the evolution of non-autonomy may be a common event. High sequence similarity between several LTR retrotransposons identified in this study and those found in distantly-related species suggests that horizontal transfer has been a significant factor in the evolution of mouse LTR retrotransposons.
Project description:Copy number variation is an important dimension of genetic diversity and has implications in development and disease. As an important model organism, the mouse is a prime candidate for copy number variant (CNV) characterization, but this has yet to be completed for a large sample size. Here we report CNV analysis of publicly available, high-density microarray data files for 351 mouse tail samples, including 290 mice that had not been characterized for CNVs previously.We found 9634 putative autosomal CNVs across the samples affecting 6.87% of the mouse reference genome. We find significant differences in the degree of CNV uniqueness (single sample occurrence) and the nature of CNV-gene overlap between wild-caught mice and classical laboratory strains. CNV-gene overlap was associated with lipid metabolism, pheromone response and olfaction compared to immunity, carbohydrate metabolism and amino-acid metabolism for wild-caught mice and classical laboratory strains, respectively. Using two subspecies of wild-caught Mus musculus, we identified putative CNVs unique to those subspecies and show this diversity is better captured by wild-derived laboratory strains than by the classical laboratory strains. A total of 9 genic copy number variable regions (CNVRs) were selected for experimental confirmation by droplet digital PCR (ddPCR).The analysis we present is a comprehensive, genome-wide analysis of CNVs in Mus musculus, which increases the number of known variants in the species and will accelerate the identification of novel variants in future studies.