Construction and characterization of a genomic BAC library for the Mus m. musculus mouse subspecies (PWD/Ph inbred strain)

BACKGROUND: The genome of classical laboratory strains of mice is an artificial mosaic of genomes originated from several mouse subspecies with predominant representation (>90%) of the Mus m. domesticus component. Mice of another subspecies, East European/Asian Mus m. musculus, can interbreed with the classical laboratory strains to generate hybrids with unprecedented phenotypic and genotypic variations. To study these variations in depth we prepared the first genomic large insert BAC library from an inbred strain derived purely from the Mus m. musculus-subspecies. The library will be used to seek and characterize genomic sequences controlling specific monogenic and polygenic complex traits, including modifiers of dominant and recessive mutations. RESULTS: A representative mouse genomic BAC library was derived from a female mouse of the PWD/Ph inbred strain of Mus m. musculus subspecies. The library consists of 144 768 primary clones from which 97% contain an insert of 120 kb average size. The library represents an equivalent of 6.7 × mouse haploid genome, as estimated from the total number of clones carrying genomic DNA inserts and from the average insert size. The clones were arrayed in duplicates onto eight high-density membranes that were screened with seven single-copy gene probes. The individual probes identified four to eleven positive clones, corresponding to 6.9-fold coverage of the mouse genome. Eighty-seven BAC-ends of PWD/Ph clones were sequenced, edited, and aligned with mouse C57BL/6J (B6) genome. Seventy-three BAC-ends displayed unique hits on B6 genome and their alignment revealed 0.92 single nucleotide polymorphisms (SNPs) per 100 bp. Insertions and deletions represented 0.3% of the BAC end sequences. CONCLUSION: Analysis of the novel genomic library for the PWD/Ph inbred strain demonstrated coverage of almost seven mouse genome equivalents and a capability to recover clones for specific regions of PWD/Ph genome. The single nucleotide polymorphism between the strains PWD/Ph and C57BL/6J was 0.92/100 bp, a value significantly higher than between classical laboratory strains. The library will serve as a resource for dissecting the phenotypic and genotypic variations between mice of the Mus m. musculus subspecies and classical laboratory mouse strains

Global transcriptome analysis of the C57BL/6J mouse testis by SAGE: evidence for nonrandom gene order

BACKGROUND: We generated the gene expression profile of the total testis from the adult C57BL/6J male mice using serial analysis of gene expression (SAGE). Two high-quality SAGE libraries containing a total of 76 854 tags were constructed. An extensive bioinformatic analysis and comparison of SAGE transcriptomes of the total testis, testicular somatic cells and other mouse tissues was performed and the theory of male-biased gene accumulation on the X chromosome was tested. RESULTS: We sorted out 829 genes predominantly expressed from the germinal part and 944 genes from the somatic part of the testis. The genes preferentially and specifically expressed in total testis and testicular somatic cells were identified by comparing the testis SAGE transcriptomes to the available transcriptomes of seven non-testis tissues. We uncovered chromosomal clusters of adjacent genes with preferential expression in total testis and testicular somatic cells by a genome-wide search and found that the clusters encompassed a significantly higher number of genes than expected by chance. We observed a significant 3.2-fold enrichment of the proportion of X-linked genes specific for testicular somatic cells, while the proportions of X-linked genes specific for total testis and for other tissues were comparable. In contrast to the tissue-specific genes, an under-representation of X-linked genes in the total testis transcriptome but not in the transcriptomes of testicular somatic cells and other tissues was detected. CONCLUSION: Our results provide new evidence in favor of the theory of male-biased genes accumulation on the X chromosome in testicular somatic cells and indicate the opposite action of the meiotic X-inactivation in testicular germ cells

Prediction of single-nucleotide substitutions that result in exon skipping: identification of a splicing silencer in BRCA1 exon 6

Missense, nonsense and translationally silent mutations can inactivate genes by altering the inclusion of mutant exons in mRNA, but their overall frequency amongst disease-causing exonic substitutions is unknown. Here, we have tested missense and silent mutations deposited in the BRCA1 mutation databases of unclassified variants for their effects on exon inclusion. Analysis of 21 BRCA1 variants using minigene assays revealed a single exon-skipping mutation c.231G>T. Comprehensive mutagenesis of an adjacent 12-nt segment showed that this silent mutation resulted in a higher level of exon skipping than 35 other single-nucleotide substitutions. Exon inclusion levels of mutant constructs correlated significantly with predicted splicing enhancers/silencers, prompting the development of two online utilities freely available at http://www.dbass.org.uk. EX-SKIP quickly estimates which allele is more susceptible to exon skipping whereas HOT-SKIP examines all possible mutations at each exon position and identifies candidate exon-skipping positions/substitutions. We demonstrate that the distribution of exon-skipping and disease-associated substitutions previously identified in coding regions was biased toward top-ranking HOT-SKIP mutations. Finally, we show that proteins 9G8, SC35, SF2/ASF, Tra2 and hnRNP A1 were associated with significant alterations of BRCA1 exon 6 inclusion in the mRNA. Together, these results facilitate prediction of exonic substitutions that reduce exon inclusion in mature transcripts

Prediction of single‐nucleotide substitutions that result in exon skipping: identification of a splicing silencer in BRCA1

Missense, nonsense and translationally silent mutations can inactivate genes by altering the inclusion of mutant exons in mRNA, but their overall frequency amongst disease-causing exonic substitutions is unknown. Here, we have tested missense and silent mutations deposited in the BRCA1 mutation databases of unclassified variants for their effects on exon inclusion. Analysis of 21 BRCA1 variants using minigene assays revealed a single exon-skipping mutation c.231G>T. Comprehensive mutagenesis of an adjacent 12-nt segment showed that this silent mutation resulted in a higher level of exon skipping than 35 other single-nucleotide substitutions. Exon inclusion levels of mutant constructs correlated significantly with predicted splicing enhancers/silencers, prompting the development of two online utilities freely available at http://www.dbass.org.uk. EX-SKIP quickly estimates which allele is more susceptible to exon skipping whereas HOT-SKIP examines all possible mutations at each exon position and identifies candidate exon-skipping positions/substitutions. We demonstrate that the distribution of exon-skipping and disease-associated substitutions previously identified in coding regions was biased toward top-ranking HOT-SKIP mutations. Finally, we show that proteins 9G8, SC35, SF2/ASF, Tra2 and hnRNP A1 were associated with significant alterations of BRCA1 exon 6 inclusion in the mRNA. Together, these results facilitate prediction of exonic substitutions that reduce exon inclusion in mature transcripts

Development of a human mitochondrial oligonucleotide microarray (h-MitoArray) and gene expression analysis of fibroblast cell lines from 13 patients with isolated F1Fo ATP synthase deficiency

<p>Abstract</p> <p>Background</p> <p>To strengthen research and differential diagnostics of mitochondrial disorders, we constructed and validated an oligonucleotide microarray (h-MitoArray) allowing expression analysis of 1632 human genes involved in mitochondrial biology, cell cycle regulation, signal transduction and apoptosis. Using h-MitoArray we analyzed gene expression profiles in 9 control and 13 fibroblast cell lines from patients with F₁F_oATP synthase deficiency consisting of 2 patients with mt9205ΔTA microdeletion and a genetically heterogeneous group of 11 patients with not yet characterized nuclear defects. Analysing gene expression profiles, we attempted to classify patients into expected defect specific subgroups, and subsequently reveal group specific compensatory changes, identify potential phenotype causing pathways and define candidate disease causing genes.</p> <p>Results</p> <p>Molecular studies, in combination with unsupervised clustering methods, defined three subgroups of patient cell lines – M group with mtDNA mutation and N1 and N2 groups with nuclear defect. Comparison of expression profiles and functional annotation, gene enrichment and pathway analyses of differentially expressed genes revealed in the M group a transcription profile suggestive of synchronized suppression of mitochondrial biogenesis and G1/S arrest. The N1 group showed elevated expression of complex I and reduced expression of complexes III, V, and V-type ATP synthase subunit genes, reduced expression of genes involved in phosphorylation dependent signaling along MAPK, Jak-STAT, JNK, and p38 MAP kinase pathways, signs of activated apoptosis and oxidative stress resembling phenotype of premature senescent fibroblasts. No specific functionally meaningful changes, except of signs of activated apoptosis, were detected in the N2 group. Evaluation of individual gene expression profiles confirmed already known <it>ATP6/ATP8 </it>defect in patients from the M group and indicated several candidate disease causing genes for nuclear defects.</p> <p>Conclusion</p> <p>Our analysis showed that deficiency in the ATP synthase protein complex amount is generally accompanied by only minor changes in expression of ATP synthase related genes. It also suggested that the site (mtDNA vs nuclear DNA) and the severity (ATP synthase content) of the underlying defect have diverse effects on cellular gene expression phenotypes, which warrants further investigation of cell cycle regulatory and signal transduction pathways in other OXPHOS disorders and related pharmacological models.</p

Gene order in eukaryotic genomes: an analysis using sequence-based gene expression data

Katedra genetiky a mikrobiologieDepartment of Genetics and MicrobiologyFaculty of SciencePřírodovědecká fakult

Gene order in eukaryotic genomes: an analysis using sequence-based gene expression data

ZÁVĚRY 61 6. ZÁVĚRY 6.1. Analýza genů exprimovaných v myším varleti a jejich uspořádání v genomu Pomocí expresního profilování metodou SAGE (sériová analýza genové exprese) byl vytvořen katalog genů exprimovaných ve varleti dospělých myší. Byly identifikovány poziční klastry genů na chromosomech obsahující geny s preferenční expresí ve varleti. Tyto klastry obsahovaly signifikantně vyšší počet genů než v náhodně vygenerovaných genomech. Geny specificky exprimované v somatických buňkách myšího varlete byly signifikantně obohacené na chromosomu X, což podporuje teorii o hromadění genů preferenčně exprimovaných v samčích tkáních na chromosomu X. Geny exprimované z chromosomu X byly ochuzené v transkriptomu celého myšího varlete, což je v souladu s představou o inaktivaci chromosomu X během prvního meiotického dělení. Byla vytvořena veřejně přístupná internetová databáze Mouse SAGE Site, která shromažďuje expresní data z myších tkání a buněčných liniích vytvořená pomocí metody SAGE. 6.2. Genový obsah chromosomu Z kura domácího Chromosom Z kura domácího byl signifikantně obohacený o geny preferenčně exprimované v samčím mozku. ZÁVĚRY 62 Geny s preferenční expresí v samičím mozku vykazovaly náznak ochuzení na chromosomu Z. Podobně, geny specificky exprimované ve vaječnících byly na chromosomu Z...ZÁVĚRY 61 6. ZÁVĚRY 6.1. Analýza genů exprimovaných v myším varleti a jejich uspořádání v genomu Pomocí expresního profilování metodou SAGE (sériová analýza genové exprese) byl vytvořen katalog genů exprimovaných ve varleti dospělých myší. Byly identifikovány poziční klastry genů na chromosomech obsahující geny s preferenční expresí ve varleti. Tyto klastry obsahovaly signifikantně vyšší počet genů než v náhodně vygenerovaných genomech. Geny specificky exprimované v somatických buňkách myšího varlete byly signifikantně obohacené na chromosomu X, což podporuje teorii o hromadění genů preferenčně exprimovaných v samčích tkáních na chromosomu X. Geny exprimované z chromosomu X byly ochuzené v transkriptomu celého myšího varlete, což je v souladu s představou o inaktivaci chromosomu X během prvního meiotického dělení. Byla vytvořena veřejně přístupná internetová databáze Mouse SAGE Site, která shromažďuje expresní data z myších tkání a buněčných liniích vytvořená pomocí metody SAGE. 6.2. Genový obsah chromosomu Z kura domácího Chromosom Z kura domácího byl signifikantně obohacený o geny preferenčně exprimované v samčím mozku. ZÁVĚRY 62 Geny s preferenční expresí v samičím mozku vykazovaly náznak ochuzení na chromosomu Z. Podobně, geny specificky exprimované ve vaječnících byly na chromosomu Z...Department of Genetics and MicrobiologyKatedra genetiky a mikrobiologiePřírodovědecká fakultaFaculty of Scienc

Gene order in eukaryotic genomes: an analysis using sequence-based gene expression data

ZÁVĚRY 61 6. ZÁVĚRY 6.1. Analýza genů exprimovaných v myším varleti a jejich uspořádání v genomu Pomocí expresního profilování metodou SAGE (sériová analýza genové exprese) byl vytvořen katalog genů exprimovaných ve varleti dospělých myší. Byly identifikovány poziční klastry genů na chromosomech obsahující geny s preferenční expresí ve varleti. Tyto klastry obsahovaly signifikantně vyšší počet genů než v náhodně vygenerovaných genomech. Geny specificky exprimované v somatických buňkách myšího varlete byly signifikantně obohacené na chromosomu X, což podporuje teorii o hromadění genů preferenčně exprimovaných v samčích tkáních na chromosomu X. Geny exprimované z chromosomu X byly ochuzené v transkriptomu celého myšího varlete, což je v souladu s představou o inaktivaci chromosomu X během prvního meiotického dělení. Byla vytvořena veřejně přístupná internetová databáze Mouse SAGE Site, která shromažďuje expresní data z myších tkání a buněčných liniích vytvořená pomocí metody SAGE. 6.2. Genový obsah chromosomu Z kura domácího Chromosom Z kura domácího byl signifikantně obohacený o geny preferenčně exprimované v samčím mozku. ZÁVĚRY 62 Geny s preferenční expresí v samičím mozku vykazovaly náznak ochuzení na chromosomu Z. Podobně, geny specificky exprimované ve vaječnících byly na chromosomu Z..

Gene order in eukaryotic genomes: an analysis using sequence-based gene expression data

Department of Genetics and MicrobiologyKatedra genetiky a mikrobiologieFaculty of SciencePřírodovědecká fakult

The Mouse SAGE Site: database of public mouse SAGE libraries

The Mouse SAGE Site is a web-based database of all available public libraries generated by the Serial Analysis of Gene Expression (SAGE) from various mouse tissues and cell lines. The database contains mouse SAGE libraries organized in a uniform way and provides web-based tools for browsing, comparing and searching SAGE data with reliable tag-to-gene identification. A modified approach based on the SAGEmap database is used for reliable tag identification. The Mouse SAGE Site is maintained on an ongoing basis at the Institute of Molecular Genetics, Academy of Sciences of the Czech Republic and is accessible at the internet address http://mouse.biomed.cas.cz/sage/