Project description:Homozygous masterblind (mbl-/-) zebrafish exhibit reduced or absent eyes and telecephalon, and the expansion of the diencephalic fates to the front of the brain. A missense mutation in the GSK3-binding domain of zebrafish axin1, a scaffolding protein in the Wnt signaling pathway, results in the mbl phenotype. In an effort to identify and study the genes affected by Wnt signaling, we used a 14,000-oligonucleotide-gene microarray to determine differentially expressed genes in mbl/axin1 (-/-) and wild type control zebrafish embryos and larvae. Keywords: zebrafish, Danio rerio, wild-type mbl, axin1, development
Project description:MBL-1 is an RNA-binding protein important for the differentiation and development of many animal tissues. Our aim was to identify the binding targets of the MBL-1 protein in C. elegans. RNA from a CRISPR/CAS9-generated strain expressing a 3xFLAG-tagged MBL-1 protein was immunopreciprecipitated with an anti-FLAG antibody. RNA-seq was then performed to identify binding targets of the RNA-binding protein MBL-1. Experiments were performed at the L4 stage.
Project description:MBL-1 is an RNA-binding protein important for the differentiation and development of many animal tissues. An evolutionarily conserved alternative splicing mechanism generates MBL-1 isoforms that are either expressed in the nucleus or show a more cytoplasmic distribution. We used small RNA-seq to investigate the individual contribution of evolutionarily conserved mbl-1 isoform expression of C. elegans miRNA expression. The analysis was done on L4 stage animals
Project description:Ozone is a common pollutant and a potent oxidant in industrialized nations. The mechanisms of ozone-induced lung injury and differential susceptibility are not fully understood. Ozone-induced lung inflammation is mediated, in part, by the innate immune system. We hypothesized that mannose binding lectin (MBL), which has a central role in the activation of the complement pathway of innate immunity, is a necessary component of the pro-inflammatory events caused by ozone-mediated activation of the innate immune system. Wild-type (Mbl+/+) and MBL deficient (Mbl-/-) mice were exposed to ozone (0.3 ppm) for 24, 48, and 72 hours, and bronchoalveolar lavage fluid (BALF) was examined for inflammatory markers. Compared to Mbl+/+ mice, significantly greater mean BALF eosinophils, neutrophils and neutrophil attractants CXCL2 (MIP-2) and CXCL5 (LIX) were found in Mbl-/- mice exposed to ozone. Using genome-wide mRNA microarray analyses, we identified significant differences in expression response profiles and networks at baseline (e.g. NRF2 mediated oxidative stress response) and after exposure (e.g. humoral immune response) between Mbl+/+ and Mbl-/- mice. The microarray data were further analyzed using a pattern recognition analysis for Extracting Patterns and Identifying co-expressed Genes (EPIG), and discovered several informative differential response patterns and subsequent gene sets, including antimicrobial response and inflammatory response. These novel findings demonstrate that targeted deletion of Mbl caused differential expression of inflammation-related gene sets basally and after exposure to ozone, and significantly reduced pulmonary inflammation thus indicating an important innate immunomodulatory role of the gene in this model.
Project description:MBL-1 is an RNA-binding protein important for the differentiation and development of many animal tissues. An evolutionarily conserved alternative splicing mechanism generates MBL-1 isoforms that are either expressed in the nucleus or show a more cytoplasmic distribution. We used RNA-seq to investigate the individual contribution of evolutionarily conserved mbl-1 isoform expression of C. elegans gene expression and to identify pathways associated with isoform expression. The analysis was done on L4 stage animals
Project description:The muscleblind family of mRNA splicing regulators is conserved across species and regulate the development of muscles and the nervous system. However, how Muscleblind proteins regulate neuronal fate specification and neurite morphogenesis at the single-neuron level is not well understood. In this study, we found that the C. elegans Muscleblind/MBL-1 promotes axonal growth in the touch receptor neurons (TRNs) by regulating microtubule stability and polarity. Transcriptomic analysis identified dozens of MBL-1-controlled splicing events in genes related to neuronal differentiation or microtubule functions. Among the MBL- 1 targets, the LIM-domain transcription factor mec-3 is the terminal selector for the TRN fate and induces the expression of many TRN terminal differentiation genes. MBL-1 promotes the splicing of the mec-3 long isoform, which are essential for TRN fate specification, and inhibits the short isoforms that have much weaker activities in activating downstream genes. MBL-1 promotes mec-3 splicing through three “YGCU(U/G)Y” motifs located downstream of the included exon, which is similar to the mechanisms used by mammalian Muscleblind and suggests a deeply conserved context-dependency of the splicing regulation. Interestingly, the expression of mbl-1 in the TRNs is dependent on the mec-3 long isoform, indicating a positive feedback loop between the splicing regulator and the terminal selector. Finally, through a forward genetic screen, we found that MBL-1 promotes neurite growth partly by inhibiting the DLK-1/p38 MAPK pathway. In summary, our study provides mechanistic understanding of the role of Muscleblind in regulating cell fate specification and neuronal morphogenesis.
Project description:Myotonic dystrophy type 1 (DM1) is a neuro-muscular disorder caused by CTG triplet expansion in the 3-UTR of the DMPK gene. Mutated transcripts aggregate in muscle nuclei and sequester the MBNL1 splicing factor. To assess the involvement of Mbl sequestration on transcriptpion deregulation in DM1, we performed genome wide analyses of gene expression of DM1 Drosophila model in three different genetic contexts: Mef>mblRNAi, Mef>600CTG, Mef>960CTG vs. Mef>lacZ control line.