Project description:We define a pathogenic role for a ß-catenin-activated genetic pathway in murine renal dysplasia. Cre-mediated stabilization of ß-catenin in the ureteric cell lineage prior to the onset of kidney development increased ß-catenin levels and caused renal aplasia or severe hypodysplasia. A genome-wide analysis of mRNA expression in dysplastic tissue identified down-regulation of genes required for ureteric branching and up regulation of Tgfß2 and Dkk1.
Project description:We define a pathogenic role for a ß-catenin-activated genetic pathway in murine renal dysplasia. Cre-mediated stabilization of ß-catenin in the ureteric cell lineage prior to the onset of kidney development increased ß-catenin levels and caused renal aplasia or severe hypodysplasia. A genome-wide analysis of mRNA expression in dysplastic tissue identified down-regulation of genes required for ureteric branching and up regulation of Tgfß2 and Dkk1. Hoxb7-Cre:EGFP mice ( Zhao, et al. (2004) Dev Biol 276:403-415) were crossed with mice containing loxP sites flanking exon 3 of the ß-catenin allele (ß-catdelta3/delta3) (Harada,et al. (2002) Cancer Res 62:1971-1977) to generate ß-catenin gain-of-function mutant mice specific to the uteric bud, termed ß-catGOF-UB .Eighteen ß-catGOF-UB mutant kidneys and 9 WT kidneys were micro-dissected at E12.5. Mutant kidneys were divided into three random pools (n=3) consisting of 6 kidneys each and mRNA expression assessed by microarray.
Project description:SILAC based protein correlation profiling using size exclusion of protein complexes derived from Mus musculus tissues (Heart, Liver, Lung, Kidney, Skeletal Muscle, Thymus)
Project description:SILAC based protein correlation profiling using size exclusion of protein complexes derived from seven Mus musculus tissues (Heart, Brain, Liver, Lung, Kidney, Skeletal Muscle, Thymus)
Project description:Context dependent molecular cues shape the formation of the cerebral vascular network and the function of the blood-brain barrier (BBB). The Wnt/ß-catenin pathway is orchestrating CNS vascular development, but downstream mediators have not been characterized. Here we generated an endothelial cell-specific R26-Axin1 overexpression (AOE) mouse model to inhibit Wnt/ß-catenin signaling. In AOE mice we discovered that blockade of Wnt/ß-catenin pathway leads to premature regression and remodeling without compromising BBB integrity. Importantly, by comparing transcriptomes of endothelial cells from wildtype and AOE mice, we identified ADAMTSL2 as a novel Wnt/ß-catenin-induced, secreted factor, important for stabilizing the BBB during development. Zebrafish loss-of-function and gain-of-function models, further demonstrated that ADAMTSL2 is crucial for normal vascular development and could rescue vascular phenotypes in AOE zebrafish brains. In conclusion, the studies presented here reveal a hitherto unrecognized role of ADAMTSL2 as an endothelial cell-specific mediator of Wnt/ß-catenin signaling during CNS vascular development and BBB-formation.
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:Analysis of the transcriptome of ß-catenin flox/- mES cells in comparison with ß-catenin null mES cells or ß-catenin null mES cells stably transfected with an E-cadherin-?-catenin fusion protein. Expression assay was performed using the Affymetrix GeneChip Mouse Gene 1.0 ST array. The experiment includes ß-catenin flox/-, ß-catenin null and ß-catenin null E? mouse embryonic stem cells with three biological replicates for each sample.
Project description:The Wnt/ß-catenin pathway is orchestrating the development of the blood-brain barrier (BBB), but its downstream mediators have remained elusive. To identify potential effectors, we generated an endothelial cell specific Axin1 over-expressing mouse model, AOEiEC. We found that in AOEiE mice Wnt/ß-catenin signalling was down regulated leading to premature regression and remodelling without directly compromising BBB integrity. Interestingly, by comparing transcriptomes of endothelial cells from control and AOEiEC mice, we identified Adamtsl2 as a novel Wnt/ß-catenin-induced, secreted factor, important for stabilizing the cerebral vasculature during development. Importantly, loss-of-function and gain-of-function experiments revealed that Adamtsl2 alone was sufficient to rescue CNS vascular defects seen upon Wnt-signalling inhibition. Furthermore, using various cell and animal models we demonstrate that Adamtsl2 exerts its function by fine-tuning the TGFβ signalling pathway in CNS vessels. In conclusion, this study implicates Adamtsl2 as a mediator of Wnt/ß-catenin signalling during BBB development by linking it to TGFβ signalling.