Project description:FGF signaling has been implicated in the regulation of osteogenesis in both intramembranous and endochondral ossification. In the developing palate, the anterior bony palate forms by direct differentiation of cranial neural crest-derived mesenchymal cells, but the signals that regulate osteogenic cell fate remains unclear. In the present study, we present evidence that locally activated FGF8 signaling in the anterior palate leads to complete bone loss of the palatine process of the maxilla (ma) and ectopic cartilage formation. This aberrant developmental process was accompanied by significantly elevated level of cell proliferation, which contributes to abnormally thickened ma, and complete inhibition of Osterix expression, which accounts for the lack of bone formation. Consistent with the phenotype, RNA-Sequencing (RNA-Seq) analysis further demonstrated that augmented FGF8 signaling downregulated genes involved in ossification, biomineral tissue development, and bone mineralization, but upregulated genes involved in cell proliferation, cartilage development, and cell fate commitment. Expression validation of selected genes supported the RNA-Seq results. We conclude that FGF signaling functions as a negative regulator of osteogenic fate but promotes chondrogenesis of cranial neural crest cell-derived mesenchyme in the hard palate, which will have implication in directed differentiation of precursor cells for clinical application.
Project description:Being a transcription factor, Shox2 binds to specific DNA sites to regulate gene expression via modulating chromatin status. To investigate the impact of Shox2 on the chromatin accessible landscape in the anterior hard palate, we subjected FACS-sorted Shox2+ cells from the palate of E14.5 Shox2Cre/+;Nkx2.5F/F;R26RmTmG and Shox2Cre/-;Nkx2.5F/F;R26RmTmG mice to ATAC-Seq analysis.
Project description:Tamoxifen (TAM), a widely-used drug in treating breast cancer, has been reported to be associated with craniofacial defects including micrognathia and cleft palate in humans. However, the exact effects of TAM on the developing palate remain unclear. In the present study, we conclude that excess TAM exposure causes cleft palate defect in mice by regulating MAPK pathways, which implicates the importance of tightly regulated MAPK signaling in palate development and provides a basis for further exploration of the molecular etiology of cleft palate defects caused by environmental factors.
Project description:The involvement of skeletal muscle in the process of palatal development in mammals is an example of Waddingtonian epigenetics. Our earlier study showed that the cleft palate develops in the complete absence of skeletal musculature during embryonic development in mice. This contrasts with previous beliefs that tongue obstruction prevents the elevation and fusion of the palatal shelves. We argue that the complete absence of mechanical stimuli from the adjacent muscle, i.e., the lack of both static and dynamic loading, results in disordered palatogenesis. We further suggest that proper fusion of the palatal shelves depends not only on mechanical but also on paracrine contributions from the muscle. The muscle's paracrine role in the process of palatal fusion is achieved through its being a source of certain secreted and/or circulatory proteins. A cDNA microarray analysis revealed differentially expressed genes in the cleft palate of amyogenic mouse fetuses and suggested candidate molecules with a novel function in palatogenesis (e.g., Tgfbr2, Bmp7, Trim71, E2f5, Ddx5, Gfap, Sema3f). In particular, we report on Gdf11 mutant mouse that has cleft palate, and on several genes whose distribution is normally restricted to the muscle (completely absent in our amyogenic mouse model), but which are found down-regulated in amyogenic mouse cleft palate. These molecules probably present a subset of paracrine cues that influence palatogenesis from the adjacent muscle. Future studies will elucidate the role of these genes in muscle-palate crosstalk, connecting the cues produced by the muscle with the cartilage and bone tissue's responses to these cues, through various degrees of cell proliferation, death, differentiation and tissue fusion.
Project description:Nitrate-reducing iron(II)-oxidizing bacteria are widespread in the environment contribute to nitrate removal and influence the fate of the greenhouse gases nitrous oxide and carbon dioxide. The autotrophic growth of nitrate-reducing iron(II)-oxidizing bacteria is rarely investigated and poorly understood. The most prominent model system for this type of studies is enrichment culture KS, which originates from a freshwater sediment in Bremen, Germany. To gain insights in the metabolism of nitrate reduction coupled to iron(II) oxidation under in the absence of organic carbon and oxygen limited conditions, we performed metagenomic, metatranscriptomic and metaproteomic analyses of culture KS. Raw sequencing data of 16S rRNA amplicon sequencing, shotgun metagenomics (short reads: Illumina; long reads: Oxford Nanopore Technologies), metagenome assembly, raw sequencing data of shotgun metatranscriptomes (2 conditions, triplicates) can be found at SRA in https://www.ncbi.nlm.nih.gov/bioproject/PRJNA682552. This dataset contains proteomics data for 2 conditions (heterotrophic and autotrophic growth conditions) in triplicates.
Project description:Background: The FACEBASE consortium was established in part to create a central resource for craniofacial researchers. One purpose is to provide a molecular anatomy of craniofacial development. To this end we have used a combination of laser capture microdissection and RNA-Seq to define the gene expression programs driving development of the murine palate. Results: We focused on the E14.5 palate, soon after medial fusion of the two palatal shelves. The palate was divided into multiple compartments, including medial and lateral, as well as oral and nasal, for both the anterior and posterior domains. A total of 25 RNA-Seq datasets were generated. The results provide a comprehensive view of the region specific expression of all transcription factors, growth factors and receptors. Paracrine interactions can be inferred from flanking compartment growth factor/receptor expression patterns. The results are validated primarily through very high concordance with extensive previously published gene expression data for the developing palate. In addition selected immunostain validations were carried out. Conclusions: This report provides an RNA-Seq based atlas of gene expression patterns driving palate development at microanatomic resolution. This FACEBASE resource is designed to fuel discovery by the craniofacial research community. Laser capture microdissection and RNA-seq were used to generate gene expression profiles of different compartments of the mouse E14.5 developing palate
Project description:We report the application of single cell transcriptome, bulk transcriptome, and chromatin accessibility analysis for investigating the role of Runx2 in regulating soft palate muscle development. By isolating single cells from soft palate tissue of wild type embryos at E13.5, E14.5 and E15.5, we describe the heterogeneity of soft palate mesenchyme during development by analyzing single cell transcriptome. Combined analysis of bulk and single cell transcriptome of soft palate from wild type and Runx2 mutant suggests Runx2 activate expression of perimysial markers. Finally, we show that Runx2 activates expression of perimysial markers probably by repressing Twist1 through chromatin accessibility analysis. This study provides the first single cell level heterogeneity analysis of developing soft palate and shows the important role of Runx2 in regulating soft palate muscle development.
Project description:Chronic acid suppression by proton pump inhibitor (PPI) has been hypothesized to alter the gut microbiota via a change in intestinal pH. To evaluate the changes in gut microbiota composition by long-term PPI treatment. Twenty-four week old F344 rats were fed with (n = 5) or without (n = 6) lansoprazole (PPI) for 50 weeks. Then, profiles of luminal microbiota in the terminal ileum were analyzed. Pyrosequencing for 16S rRNA gene was performed by genome sequencer FLX (454 Life Sciences/Roche) and analyzed by metagenomic bioinformatics.
Project description:ChIP-Sequencing on Meis2-HA in E12.5 palate, to identify Meis2 binding chromatin regions and target genes. Haploinsufficiency of MEIS2 is associated with cleft palate in humans and Meis2 inactivation leads to abnormal palate development in mice, implicating an essential role for Meis2 in palate development. However, its functional mechanisms remain unknown. In this study, we found widespread Meis2 expression in the developing palate in mice. Meis2 inactivation by Wnt1Cre in cranial neural crest cells led to the cleft of the secondary palate. Importantly, about half of Wnt1Cre;Meis2f/f mice exhibited submucous cleft, providing an excellent model for studying palatal bone formation and patterning. Consistent with a complete absence of the palatal bones, integrative analyses of Meis2 ChIP-seq, RNA-seq, and ATAC-seq results identified key osteogenic genes that are regulated directly by Meis2, indicating the fundamental role of Meis2 in palatal osteogenesis. De novo motif analysis discovered that the Meis2-bound regions possess highly enriched binding motifs of several key osteogenic transcription factors particularly Shox2. Comparison of Meis2 and Shox2 ChIP-seq analyses further revealed a genome-wide co-occupancy, in addition to their co-localization in the developing palate and physical interaction, suggesting that Shox2 and Meis2 act as partners. However, while Shox2 is required for proper palatal bone formation and is a direct downstream target of Meis2, Shox2 overexpression failed to rescue the palatal bone defects in Meis2 mutant background. These results, together with the facts that Meis2 expression is associated with high osteogenic potential and is required for the chromatin accessibility of osteogenic genes, support a vital function of Meis2 in setting up the ground state for palatal osteogenesis.