Project description:BACKGROUND: Lim1 is a homeobox gene that is essential for nephrogenesis. During metanephric kidney development, Lim1 is expressed in the nephric duct, ureteric buds, and the induced metanephric mesenchyme. Conditional ablation of Lim1 in the metanephric mesenchyme blocks the formation of nephrons at the nephric vesicle stage, leading to the production of small, non-functional kidneys that lack nephrons. METHODS: In the present study, we used Affymetrix probe arrays to screen for nephron-specific genes by comparing the expression profiles of control and Lim1 conditional mutant kidneys. Kidneys from two developmental stages, embryonic day 14.5 (E14.5) and 18.5 (E18.5), were examined. RESULTS: Comparison of E18.5 kidney expression profiles generated a list of 465 nephron-specific gene candidates that showed a more than 2-fold increase in their expression level in control kidney versus the Lim1 conditional mutant kidney. Computational analysis confirmed that this screen enriched for kidney-specific genes. Furthermore, at least twenty-eight of the top fifty (56%) candidates (or their vertebrate orthologs) were previously reported to have a nephron-specific expression pattern. Our analysis of E14.5 expression data yielded 41 candidate genes that are up-regulated in the control kidneys compared to the conditional mutants. Three of them are related to the Notch signaling pathway that is known to be important in cell fate determination and nephron patterning. CONCLUSIONS: Therefore, we demonstrate that Lim1 conditional mutant kidneys serve as a novel tissue source for comprehensive expression studies and provide a means to identify nephron-specific genes. Keywords: tissue specificity, time course, development, kidney, metanephric mesenchyme, nephron, Lim1, knockout mice, conditional knockout
Project description:The Lim1 gene has essential functions during several stages of kidney development. In particular, a tissue specific knockout in the early metanephric mesenchyme results in the formation of the earliest nephron precursor, the renal vesicle, but failure of this structure to progress to the next stage, the comma shaped body. To better understand the molecular nature of this developmental arrest we used a laser capture microdissection-microarray strategy to examine the perturbed gene expression pattern of the mutant renal vesicles. Among the genes found differently expressed were Chrdl2, an inhibitor of BMP signaling, the pro-apoptotic factor Bmf, as well as myob5, an atypical myosin which modulates chemokine and transferring signaling, and pdgfr1, which is important in epithelial folding. Of particular interest, the microarray data indicated that the Dkk1 gene, which encodes an inhibitor of Wnt signaling, was downregulated nine fold in mutants. This was confirmed by in situ hybridizations. It is interesting to note that Lim1 and Dkk1 mutant mice have striking similarities in phenotype. These results suggest that the Dkk1 gene might be a key downstream effector of Lim1 function. Experiment Overall Design: We compared gene expression profiles of wild type and mutant Lim1 renal vesicles, which were isolated from E12.5 kidneys by laser capture microdissection. Nine biological independent samples were examined, with four mutant and five wild type. Each sample included approximately 30-50 renal vesicles. Detailed protocols are described at GUDMAP.org
Project description:The Lim1 gene has essential functions during several stages of kidney development. In particular, a tissue specific knockout in the early metanephric mesenchyme results in the formation of the earliest nephron precursor, the renal vesicle, but failure of this structure to progress to the next stage, the comma shaped body. To better understand the molecular nature of this developmental arrest we used a laser capture microdissection-microarray strategy to examine the perturbed gene expression pattern of the mutant renal vesicles. Among the genes found differently expressed were Chrdl2, an inhibitor of BMP signaling, the pro-apoptotic factor Bmf, as well as myob5, an atypical myosin which modulates chemokine and transferring signaling, and pdgfr1, which is important in epithelial folding. Of particular interest, the microarray data indicated that the Dkk1 gene, which encodes an inhibitor of Wnt signaling, was downregulated nine fold in mutants. This was confirmed by in situ hybridizations. It is interesting to note that Lim1 and Dkk1 mutant mice have striking similarities in phenotype. These results suggest that the Dkk1 gene might be a key downstream effector of Lim1 function. Keywords: Lim1 mutant, kidney development, gene expression profile comparison
Project description:E11.5 metanephric mesenchyme and ureteric bud were dissected from the E11.5 kidney rudiment using fine manual microdissection (ureteric bud only) or both fine manual microdissection and laser capture microdissection (metanephric mesenchyme) to define the gene expression profiles of these structures. Additionally, HoxA11, HoxD11 compound null E11.5 metanephric mesenchyme was obtained through laser capture microdissection allowing analysis of possible Hox targets in kidney development. Targets from multiple biological replicates of each were generated and the expression profiles were determined using Affymetrix MOE430_v2 arrays. Keywords: embryonic metanephric kidney, kidney development, Hoxa11, Hoxd11, compound null targeted mice
Project description:We used micro-dissection with FACS sorting techniques to isolate single cells from the metanephric mesenchyme of the E11.5 developing kidney. A subset of these single cell populations is analysed individually via Fluidigm single cell analysis. This analysis will determine the transcriptional profile of each cell type, identify compartment specific transcripts, compartment specific transcript isoforms and cell-type specific long-noncoding RNAs. In addition the unbiased nature of RNA-SEQ will potentially identify novel transcripts that have not been annotated in the database. Kidneys are harvested from Tg(Crym-EGFP)GF82Gsat mice. Single cells are extracted from E11.5 metanephric mesenchyme using manual micro-dissection techniques. A subset of these cells is analyzed individually via Fluidigm single cell analysis. The long term goal is to generate a transcriptional atlas of the developing kidney.
Project description:E11.5 metanephric mesenchyme and ureteric bud were dissected from the E11.5 kidney rudiment using fine manual microdissection (ureteric bud only) or both fine manual microdissection and laser capture microdissection (metanephric mesenchyme) to define the gene expression profiles of these structures. Additionally, HoxA11, HoxD11 compound null E11.5 metanephric mesenchyme was obtained through laser capture microdissection allowing analysis of possible Hox targets in kidney development. Targets from multiple biological replicates of each were generated and the expression profiles were determined using Affymetrix MOE430_v2 arrays. Using microdissection techniques, ureteric bud and metanephric mesenchyme were dissected from E11.5 kidney rudiments allowing the identificated genes specifically regulated in either structure. In addition, Hoxa11, Hoxd11 compound null E11.5 metanephric mesenchyme were normalized to wild type embryonic controls allowing the identification of potential Hox targets in normal kidney development. Each structure/genotype were represented in biological (seperate embryo) replicate.
Project description:In this study we identify molecules with highly restricted expression patterns during the initial stages of metanephric development, when the ureteric bud has entered the metanephric mesenchyme and initiated branching morphogenesis. Using the Affymetrix Mouse Genome 430 2.0 Array, we compare gene expression patterns in ureteric bud tips, stalks and metanephric mesenchymes from mouse E12.5 embryos. To identify conserved molecular pathways, we also analyze transcriptional profiles in rat E13.5 ureteric buds and metanephric mesenchymes using the Affymetrix Rat Genome U34 Set. Taken together, these data sets help to identify conserved and highly localized transcripts in the metanephric kidney. Keywords = Mus musculus Keywords = Rattus norvegicus Keywords = metanephric mesenchyme Keywords = ureteric bud Keywords = ureteric bud tips Keywords = ureteric bud stalks Keywords = molecular screen for spatially restricted transcripts Keywords: other
Project description:Triplicate pairwise comparsion of FACS sorted GFP+ve Vs GFP-ve cells from the kidneys of the HoxB7-GFP transgenic mice on compugen 22K mouse arrays. HoxB7-GFP mice express GFP in the ureteric tree and its derivatives while the metanephric mesenchyme, interstitium, developing vasculature etc do not.
Project description:Triplicate pairwise comparsion of FACS sorted GFP+ve Vs GFP-ve cells from the kidneys of the HoxB7-GFP transgenic mice on compugen 22K mouse arrays. HoxB7-GFP mice express GFP in the ureteric tree and its derivatives while the metanephric mesenchyme, interstitium, developing vasculature etc do not. Keywords: repeat sample
Project description:In this study we identify molecules with highly restricted expression patterns during the initial stages of metanephric development, when the ureteric bud has entered the metanephric mesenchyme and initiated branching morphogenesis. Using the Affymetrix Mouse Genome 430 2.0 Array, we compare gene expression patterns in ureteric bud tips, stalks and metanephric mesenchymes from mouse E12.5 embryos. To identify conserved molecular pathways, we also analyze transcriptional profiles in rat E13.5 ureteric buds and metanephric mesenchymes using the Affymetrix Rat Genome U34 Set. Taken together, these data sets help to identify conserved and highly localized transcripts in the metanephric kidney.