Project description:Cleft palate is among the most common structural birth defects in humans. Previous studies have shown that mutations in FOXF2 are associated with cleft palate in humans and mice and that Foxf2 acts in a Shh-Foxf-Fgf18-Shh molecular network controlling palatal shelf growth. In this study, we generated mice carrying 3xFLAG epitope-tagged endogenous Foxf2 protein using the CRISPR/Cas9-mediated genome editing technology and characterized genome-wide Foxf2 binding sites in the developing palatal shelves using chromatin immunoprecipitation and genome sequencing (ChIP-seq). By combined analysis of ChIP-seq and RNA-seq datasets we identified a large list of Foxf2 target genes. Further analyses demonstrate that Foxf2 directly regulate expression of several genes encoding ECM or ECM modifiers during palate development. Moreover, our ChIP-seq and RNA-seq datasets provide an excellent resource for comprehensive understanding of the molecular network controlling palate development.
Project description:The tongue is a specialized muscular organ that performs multiple essential functions including mastication, deglutition, oral sensation, oral cleansing, airway maintenance and vocalization. In this study, we show Foxf1/Foxf2 serves as key mediators of hedgehog signaling in regulating myoblast migration, differentiation, and intrinsic tongue muscle organization. We took advantage of the Foxf2FLAG mice which carries 3xFLAG epitope-tagged endogenous Foxf2 protein and characterized genome-wide Foxf2 binding sites in the developing tongues using chromatin immunoprecipitation and genome sequencing (ChIP-seq). Further analyses demonstrate that Foxf1/2 transcription factors directly control the expression of Hgf, Tgfb2, and Tgfb3, to regulate tongue myogenesis.
Project description:Previous studies have identified the odd-skipped related 2 (Osr2) transcription factor as a key intrinsic regulator of palatal shelf growth and morphogenesis. However, little is known about the molecular program acting downstream of Osr2 in the regulation of palatogenesis. In this study, we isolated palatal mesenchyme cells from embryonic day 12.5 (E12.5) and E13.5 Osr2RFP/+ and Osr2RFP/- mutant mouse embryos and performed whole transcriptome RNA sequencing analyses. Differential expression analysis of the RNA sequencing datasets revealed that expression of 70 genes was upregulated and expression of 61 genes was downregulated by >1.5-fold at both E12.5 and E13.5 in the Osr2RFP/- palatal mesenchyme cells, in comparison with Osr2RFP/+ littermates. Gene ontology analysis revealed enrichment of signaling molecules and transcription factors crucial for skeletal development and osteoblast differentiation among those significantly upregulated in the Osr2 mutant palatal mesenchyme. Using quantitative real-time polymerase chain reaction (RT-PCR)and in situ hybridization assays, we validated that the Osr2-/- embryos exhibit significantly increased and expanded expression of many osteogenic pathway genes, including Bmp3, Bmp5, Bmp7, Mef2c, Sox6, and Sp7 in the developing palatal mesenchyme. Furthermore, we demonstrate that expression of Sema3a, Sema3d, and Sema3e, is ectopically activated in the developing palatal mesenchyme in Osr2-/- embryos. Through chromatin immunoprecipitation, followed by RT-PCR analysis, we demonstrate that endogenous Osr2 protein binds to the promoter regions of the Sema3a and Sema3d genes in the embryonic palatal mesenchyme. Moreover, Osr2 expression repressed the transcription from the Sema3a and Sema3d promoters in cotransfected cells. Since the Sema3 subfamily of signaling molecules plays diverse roles in the regulation of cell proliferation, migration, and differentiation, these data reveal a novel role for Osr2 in regulation of palatal morphogenesis through preventing aberrant activation of Sema3 signaling. Together, these data indicate that Osr2 controls multiple molecular pathways, including BMP and Sema3 signaling, in palate development.
Project description:Cleft palate is among the most common structural birth defects in humans. Previous studies have shown that mutations in FOXF2 are associated with cleft palate in humans and mice and that Foxf2 acts in a Shh-Foxf-Fgf18-Shh molecular network controlling palatal shelf growth. In this study, we combined RNA-seq and ChIP-seq approaches to identify direct transcriptional target genes mediating Foxf2 function in palate development in mice. Of 155 genes that exhibited Foxf2-dependent expression in the developing palatal mesenchyme, 88 contained or were located next to Foxf2-binding sites. Through in situ hybridization analyses, we demonstrate that expression of many of these target genes, including multiple genes encoding transcription factors and several encoding extracellular matrix-modifying proteins, were specifically upregulated in the posterior region of palatal shelves in Foxf2-/- mouse embryos. Foxf2 occupancy at many of these putative target loci, including Fgf18, in the developing palatal tissues was verified by ChIP-polymerase chain reaction analyses. One of the Foxf2 target genes, Chst2, encodes a carbohydrate sulfotransferase integral to glycosaminoglycan sulfation. Correlating with ectopic Chst2 expression, Foxf2-/- embryos a exhibited region-specific increase in sulfated keratan sulfate and a concomitant reduction in chondroitin sulfate accumulation in the posterior palatal mesenchyme. However, expression of the core protein of versican, a major chondroitin sulfate proteoglycan important in palatal shelf morphogenesis, was increased, whereas expression of collagen I was reduced in the corresponding region of the palatal mesenchyme. These results indicate that, in addition to regulating palatal shelf growth through the Fgf18-Shh signaling network, Foxf2 controls palatal shelf morphogenesis through regulating expression of multiple transcription factors as well as through directly controlling the synthesis and processing of extracellular matrix components in the palatal mesenchyme. Our ChIP-seq and RNA-seq data sets provide an excellent resource for comprehensive understanding of the molecular network controlling palate development.
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: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.
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: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: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.