Project description:RET/GDNF and ET3/EDNRB regulate cell survival, differentiation and migration of neural crest-derived cells. Many signalling mediators of RET have been characterized but the target genes at the end of the signalling cascade are largely unknown. Since the RET/EDNRB crosstalk has been previously shown, we used a Caenorhabditis elegans knockout strain of Nep-1, a homologue of human ECE1 (endothelin-converting enzyme-1), to identify new target genes. Transcriptome comparison between wild-type and Nep-1 strains at different stages identified vit-3 as a differentially expressed gene. Molecular studies of the vit3 mammalian homologue, Apoliporotein B (APOB), were performed in the murine Neuro2a cell line, a model of ENS development. Apob expression in Neuro2a is specifically activated by the RET/GDNF signalling pathway, since Ret silencing abolished Apob increase, and this effect is induced by MAPK P38 kinase activation. Mouse Apob promoter study revealed that there is a p53-dependent repressor element in the promoter region which blocks Apob expression and we show that actually p53 binds to this region. We demonstrated that RET/GDNF and EDNRB/endothelin 3 (ET-3) cooperate in inducing neuronal differentiation resulting in Apob activation. We also show that Apob expression is downregulated in mouse embryos homozygous for the mutation RetC620R and presenting a severe HSCR phenotype, whereas heterozygous mice, phenotypically normal, present a significant increase in Apob expression. These data suggest that Apob has an important role in RET-mediated neuronal development and APOB decrease may have an impact in human disorders where RET absence has been already identified, such as HSCR and Parkinson disease. Gene expression analysis using Affymetrix GeneChip C. elegans arrays in order to identify genes up- or down-regulated in nep-1 strains, homologue of human ECE1 (endothelin-converting enzyme 1). Comparison of the transcriptomes between wt and nep-1 strains in larval stage L3 and adult C. elegans.
Project description:RET/GDNF and ET3/EDNRB regulate cell survival, differentiation and migration of neural crest-derived cells. Many signalling mediators of RET have been characterized but the target genes at the end of the signalling cascade are largely unknown. Since the RET/EDNRB crosstalk has been previously shown, we used a Caenorhabditis elegans knockout strain of Nep-1, a homologue of human ECE1 (endothelin-converting enzyme-1), to identify new target genes. Transcriptome comparison between wild-type and Nep-1 strains at different stages identified vit-3 as a differentially expressed gene. Molecular studies of the vit3 mammalian homologue, Apoliporotein B (APOB), were performed in the murine Neuro2a cell line, a model of ENS development. Apob expression in Neuro2a is specifically activated by the RET/GDNF signalling pathway, since Ret silencing abolished Apob increase, and this effect is induced by MAPK P38 kinase activation. Mouse Apob promoter study revealed that there is a p53-dependent repressor element in the promoter region which blocks Apob expression and we show that actually p53 binds to this region. We demonstrated that RET/GDNF and EDNRB/endothelin 3 (ET-3) cooperate in inducing neuronal differentiation resulting in Apob activation. We also show that Apob expression is downregulated in mouse embryos homozygous for the mutation RetC620R and presenting a severe HSCR phenotype, whereas heterozygous mice, phenotypically normal, present a significant increase in Apob expression. These data suggest that Apob has an important role in RET-mediated neuronal development and APOB decrease may have an impact in human disorders where RET absence has been already identified, such as HSCR and Parkinson disease. Gene expression analysis using Affymetrix GeneChip C. elegans arrays in order to identify genes up- or down-regulated in nep-1 strains, homologue of human ECE1 (endothelin-converting enzyme 1).
Project description:Comparison of miRNA profiles of wildtype and lin-28(n719); lin-46(ma164) Caenorhabditis elegans nematodes at the L1 stage Two genotypes, wildtype vs. mutant. Biological replicates: 3 wild type, 3 mutant, independently grown and harvested. One replicate per slide.
Project description:Natural genetic variation is the raw material of evolution and influences disease development and progression. To analyze the effect of the genetic background on protein expression in the nematode C. elegans (Caenorhabditis elegans), the two genetically highly divergent wild-type strains N2 (Bristol) and CB4856 (Hawaii) were compared quantitatively. In total, we quantified 3,238 unique proteins in three independent SILAC (stable isotope labeling by amino acids in cell culture) experiments. The differentially expressed proteins were enriched for genes that function in insulin-signaling and stress response pathways.
Project description:Background: The force generating mechanism of muscle is evolutionarily ancient; the fundamental structural and functional components of the sarcomere are common to motile animals throughout phylogeny. Recent evidence suggests that the transcription factors that regulate muscle development are also conserved. Thus, a comprehensive description of muscle gene expression in a simple model organism should define a basic muscle transcriptome that is also expressed in animals with more complex body plans. To this end, we have applied Micro-Array Profiling of Caenorhabditis elegans Cells (MAPCeL) to muscle cell populations extracted from developing Caenorhabditis elegans embryos. Results: Fluorescence Activated Cell Sorting (FACS) was used to isolate myo-3::GFP-positive muscle cells, and their cultured derivatives, from dissociated early Caenorhabditis elegans embryos. Microarray analysis identified 6,693 expressed genes, 1,305 of which are enriched in the myo-3::GFP positive cell population relative to the average embryonic cell. The muscle-enriched gene set was validated by comparisons to known muscle markers, independently derived expression data, and GFP reporters in transgenic strains. These results confirm the utility of MAPCeL for cell type-specific expression profiling and reveal that 60% of these transcripts have human homologs. Conclusions: This study provides a comprehensive description of gene expression in developing Caenorhabditis elegans embryonic muscle cells. The finding that over half of these muscle-enriched transcripts encode proteins with human homologs suggests that mutant analysis of these genes in Caenorhabditis elegans could reveal evolutionarily conserved models of muscle gene function with ready application to human muscle pathologies. Keywords: embryonic muscle, myo-3::GFP