Project description:To determine if Sox9 was sufficient to drive mucous differentiation in the gastric epithelium, we bred mice carrying alleles for ROSA26rtTA.IRES.EGFP, TetO-Sox9, and Fgf20Cre.GFP. In these mice, cells expressing Cre will induce rtTA from the ROSA26rtTA.IRES.EGFP allele. To explore transcriptional changes following adult misexpression of Sox9, we isolated RNA from the corpus of Fgf20Cre.GFP/Cre.GFP; ROSA26rtTA.IRES.EGFP/rtTA.IRES.EGFP; TetO-Sox9 pup (misexpression animals) and ROSA26rtTA.IRES.EGFP/rtTA.IRES.EGFP; TetO-Sox9 pup (control) animals and performed RNA-sequencing.
Project description:Introduction: In addition to the well-known cartilage extracellular matrix-related expression of Sox9, we demonstrated that chondrogenic differentiation of progenitor cells is driven by a sharply defined bi-phasic expression of Sox9: an immediate early and a late (extracellular matrix associated) phase expression. In this study we aimed to determine what biological processes are driven by Sox9 during this early phase of chondrogenic differentiation. Materials: Sox9 expression in ATDC5 cells was knocked-down by siRNA transfection at the day before chondrogenic differentiation or at day 6 of differentiation. Samples were harvested at 2 hours, and 7 days of differentiation. The transcriptomes (RNA-seq approach) and proteomes (Label-free proteomics approach) were compared using pathway and network analyses. Total protein translational capacity was evaluated with the SuNSET assay, active ribosomes with polysome profiling and ribosome modus with bicistronic reporter assays. Results: Early Sox9 knockdown severely inhibited chondrogenic differentiation weeks later. Sox9 expression during the immediate early phase of ATDC5 chondrogenic differentiation regulated the expression of ribosome biogenesis factors and ribosomal protein subunits. This was accompanied by decreased translational capacity following Sox9 knockdown, and this correlated to lower amounts of active mono- and polysomes. Moreover, cap- versus IRES-mediated translation was altered by Sox9 knockdown. Sox9 overexpression was able to induce reciprocal effects to the Sox9 knockdown. Conclusion: Here we identified an essential new function for Sox9 during early chondrogenic differentiation. A role for Sox9 in regulation of ribosome amount, activity and/or composition may be crucial in preparation for the demanding proliferative phase and subsequent cartilage extracellular matrix-production of chondroprogenitors in the growth plate in vivo.
Project description:The transcription factor gene Sox9 plays various roles in development, including differentiation of the skeleton, testes, glia, and heart. Other functions of Sox9 remain enigmatic. Because Sox9 protein regulates expression of target genes, the identification of Sox9 targets should facilitate an understanding of the mechanisms of Sox9 action. To help identify Sox9 targets, we used microarray expression profiling to compare wild-type embryos to mutant embryos lacking activity for sox9a and sox9b, the zebrafish co-orthologs of Sox9. Candidate genes were further evaluated by whole mount in situ hybridization in wild-type and sox9 mutant embryos. Results identified genes expressed in cartilage (col2a1a and col11a2), retina (calb2a, calb2b, crx, neurod, rs1, sox4a and vsx1) and pectoral fin bud (klf2b and EST AI722369) as candidate targets for Sox9. Cartilage is a well-characterized Sox9 target, which validates this strategy, whereas retina represents a novel Sox9 function. Analysis of mutant phenotypes confirmed that Sox9 helps regulate the number of Müller glia and photoreceptor cells and helps organize the neural retina. These roles in eye development were previously unrecognized and reinforce the multiple functions that Sox9 plays in vertebrate development. In each experiment, RNA was isolated from 48h wildtype and sox9a, sox9b double mutant embryos and the gene expression profiles were compared using microarrays. Three biological replicate experiments were performed, and each biological replicate contained a dyeswap.
Project description:The transcription factor gene Sox9 plays various roles in development, including differentiation of the skeleton, testes, glia, and heart. Other functions of Sox9 remain enigmatic. Because Sox9 protein regulates expression of target genes, the identification of Sox9 targets should facilitate an understanding of the mechanisms of Sox9 action. To help identify Sox9 targets, we used microarray expression profiling to compare wild-type embryos to mutant embryos lacking activity for sox9a and sox9b, the zebrafish co-orthologs of Sox9. Candidate genes were further evaluated by whole mount in situ hybridization in wild-type and sox9 mutant embryos. Results identified genes expressed in cartilage (col2a1a and col11a2), retina (calb2a, calb2b, crx, neurod, rs1, sox4a and vsx1) and pectoral fin bud (klf2b and EST AI722369) as candidate targets for Sox9. Cartilage is a well-characterized Sox9 target, which validates this strategy, whereas retina represents a novel Sox9 function. Analysis of mutant phenotypes confirmed that Sox9 helps regulate the number of Müller glia and photoreceptor cells and helps organize the neural retina. These roles in eye development were previously unrecognized and reinforce the multiple functions that Sox9 plays in vertebrate development.
Project description:To investigate the effect of SOX9 on the expression profile of Huh-7 cells, we established SOX9 knockout (SOX9KO)Huh-7 cells by crisper-cas9 system.We then performed gene expression profiling analysis using data obtained from RNA-seq of Huh-7 and SOX9KO Huh-7 cells.
Project description:Introduction: In addition to the well-known cartilage extracellular matrix-related expression of Sox9, we demonstrated that chondrogenic differentiation of progenitor cells is driven by a sharply defined bi-phasic expression of Sox9: an immediate early and a late (extracellular matrix associated) phase expression. In this study we aimed to determine what biological processes are driven by Sox9 during this early phase of chondrogenic differentiation. Materials: Sox9 expression in ATDC5 cells was knocked-down by siRNA transfection at the day before chondrogenic differentiation or at day 6 of differentiation. Samples were harvested at 2 hours, and 7 days of differentiation. The mRNA sequencing library was generated using TruSeq mRNA sample preparation kit (Illumina, Eindhoven, the Netherlands). In short, mRNA was enriched using magnetic beads coated with poly-dT, followed by fragmentation. The fragmented mRNA enriched samples were subjected to cDNA synthesis by reverse transcriptase, followed by dA-tailing and ligation of specific double-stranded bar-coded adapters. Next, the library was amplified and following cleanup the sizes of the libraries were determined on an Agilent 2100 Bioanalyzer via a DNA 1000 chip according manufacturer’s protocol. Pooled libraries consisting of equal molar samples were sequenced on a high-output 75bp single read on the NextSeq500 (Illumina). For each sample, the number of reads covering one or more exons of a given transcript were extracted. Triplicates of samples that were treated with either Scrambled or Sox9 siRNAs, at two different time points, were grouped separately. A transcript was defined as expressed when all replicates of a group had at least 5 reads extracted within the transcript's region. The grouped data were then compared to one another. The fold-change difference and the p-value were calculated using R-package edgeR, after which the p-value was corrected for multiple testing (false discovery rate (FDR)-corrected). The transcriptomes using a RNA-seq approach was analyzed using pathway and network analyses. Results: Early Sox9 knockdown severely inhibited chondrogenic differentiation weeks later. Sox9 expression during the immediate early phase of ATDC5 chondrogenic differentiation regulated the expression of ribosome biogenesis factors and ribosomal protein subunits. This was accompanied by decreased translational capacity following Sox9 knockdown, and this correlated to lower amounts of active mono- and polysomes. Moreover, cap- versus IRES-mediated translation was altered by Sox9 knockdown. Sox9 overexpression was able to induce reciprocal effects to the Sox9 knockdown.
Project description:RNA from MMTV-Cre;Sox9flox/flox mouse mammary glands were compared to RNA from MMTV-Cre;Sox9+/flox glands. Results indicate that Sox9 regulates several genes that impact ductal morphogenesis in the mammary gland. The portion of the fourth mammary gland that is proximal to the intra-mammary gland lymph nodes was dissected from four 5-week-old MMTV-Cre;Sox9flox/flox females and four MMTV-Cre;Sox9+/flox females of the same age. Total RNA from each gland was extracted and hybridized to separate Affymetrix Gene 1.0 ST chips.
Project description:CRISPR/Cas9-mediated gene targeting of Sox9 from embryonic mammary progenitors cell line eMPC1. Part of a study to assess the effect of Sox9 ablation on embryonic mammary progenitor cell fate and function.
Project description:A major event in mammalian male sex determination is the induction of the testis determining factor Sry and its downstream gene Sox9. The current study provides one of the first genome wide analyses of the downstream gene binding targets for SRY and SOX9 to help elucidate the molecular control of Sertoli cell differentiation and testis development. A modified ChIP-Chip analysis using a comparative hybridization was used to identify 71 direct downstream binding targets for SRY and 109 binding targets for SOX9. Interestingly, only 5 gene targets overlapped between SRY and SOX9. In addition to the direct response element binding gene targets, a large number of atypical binding gene targets were identified for both SRY and SOX9. Bioinformatic analysis of the downstream binding targets identified gene networks and cellular pathways potentially involved in the induction of Sertoli cell differentiation and testis development. The specific DNA sequence binding site motifs for both SRY and SOX9 were identified. Observations provide insights into the molecular control of male gonadal sex determination. The current study provides one of the first genome wide analyses of the downstream gene binding targets for SRY and SOX9 to help elucidate the molecular control of Sertoli cell differentiation and testis development. At embryonic day 13 (E13) of pregnancy rats were euthanized and embryonic gonads were collected for chromatin. A modified ChIP-Chip analysis using a comparative hybridization was used to identify direct downstream binding targets for SRY and for SOX9. Then, bioinformatic analysis of the downstream binding targets was done to identify gene networks and cellular pathways that are potentially involved in the induction of Sertoli cell differentiation and testis development.
Project description:RNA from MMTV-Cre;Sox9flox/flox mouse mammary glands were compared to RNA from MMTV-Cre;Sox9+/flox glands. Results indicate that Sox9 regulates several genes that impact ductal morphogenesis in the mammary gland.