Project description:We used scRNAseq to characterize differentiation of cell populations during zebrafish craniofacial development. We focused critical stages during suture formation, and compared wildtype fish to mutants lacking the transcription factor sp7, that display striking abnormalities in skull and suture formation.
Project description:Mutations in RNA binding proteins can lead to pleiotropic phenotypes including craniofacial, skeletal, limb and neurological symptoms. Here, we show a developmental role for hnrnpul1 in the zebrafish limb, craniofacial development and in adult onset scoliosis. Furthermore, we demonstrate for the first time a role of hrnpul1 in alternative splicing regulation.
Project description:Adult zebrafish have the capacity to regenerate craniofacial ligament tissue following a complete transection injury. How this robust skeletal regeneration is achieved remains undefined. Here, we use single cell RNA sequencing to profile RNA expression from FACS sorted cranial neural crest lineage and non-cranial neural crest lineage cells (including skin and immune populations) in the first 3 days after ligament injury.
Project description:Patterning of the facial skeleton involves the precise deployment of thousands of genes in distinct regions of the pharyngeal arches. Despite their significance for craniofacial development, how genetic programs drive this regionalization remains poorly understood. Here we use combinatorial labeling of zebrafish cranial neural crest-derived cells (CNCCs) to define global gene expression along the dorsoventral axis of the developing arches. Intersection of region-specific transcriptomes with expression changes in response to signaling perturbations demonstrates complex roles for Endothelin1 (Edn1) signaling in the intermediate joint-forming region yet a surprisingly minor role in ventral-most regions. Analysis of co-variance across multiple sequencing experiments further reveals clusters of co-regulated genes, with in situ hybridization confirming the expression of novel genes with domain-specific expression. We then performed mutational analysis of a number of these genes, which uncovered antagonistic functions of two Edn1 targets, follistatin a (fsta) and emx2, in regulating cartilaginous joints in the hyoid arch. Our unbiased discovery and functional analysis of genes with regional expression in arch CNCCs reveals complex regulation by Edn1 and points to novel candidates for craniofacial disorders.
Project description:The RSK2 gene is responsible for Coffin-Lowry syndrome, an X-linked monogenic disease associating severe learning deficit andassociated to typical facial and digital abnormalities and skeletal changes. Craniofacial and dental anomalies encountered in this rare disease have been poorly characterized.
Project description:Craniofacial development involves regulation of a compendium of transcription factors, signaling molecules and epigenetic regulators. Histone deacetylases (HDACs) are involved in the regulation of cell proliferation, differentiation and homeostasis across a wide range of tissues, such as brain, cardiovascular system, muscular system, and skeletal system. However, functional role of Hdac4 during craniofacial development is still unclear. In this study, we investigated the effects of Hdac4 knockout in craniofacial skeletal development by conditionally disrupting the Hdac4 gene in cranial neural crest cells (CNCCs) using Cre-mediated recombination. Mice deficient in Hdac4 in CNCCs-derived osteoblasts demonstrated a dramatic decrease in bone formation in frontal bone. In vitro pre-osteoblasts (MC3T3-E1 cells) lacking Hdac4 exhibited reduced proliferation activity in association with dysregulation of cell cycle-related genes. These findings suggest that Hdac4 acts partially as a regulator of craniofacial skeletal development by positively regulating proliferation of CNCCs-derived osteoblasts.
Project description:The Notch pathway is a cell-cell communication system which is critical for many developmental processes, including craniofacial development. Notch receptor activation induces expression of several well-known canonical targets including those encoded by the hes and her genes in mammals and zebrafish, respectively. The function of these genes, individually and in combination, during craniofacial development is not well understood. Here, we investigated zebrafish her9 and her6 gene function during craniofacial development. We found that her9 is required for osteoblasts to efficiently mineralize bone, while cartilage is largely unaffected. Strikingly, gene expression studies in her9 mutants indicate that although progenitor cells differentiate into osteoblasts at the appropriate time and place, they fail to efficiently lay down mineralized matrix. This mineralization role of her9 is likely independent of Notch activation. In contrast, her9 also functions redundantly with her6 downstream of Jagged1b-induced Notch activation during dorsoventral craniofacial patterning. These studies disentangle distinct and redundant her gene functions during craniofacial development, including an unexpected, Notch independent, requirement during bone mineralization
Project description:Adult zebrafish hearts have the ability to regenerate. The roles of non-myocytes in this process have remained elusive. Here, we have performed 2 scRNAseq experiments on interstitial cells. Experiment 1 (E1) included interstitial cells obtained from uninjured, regenerating (3 days, 7 days and 14 days post-apical amputation). Experiment 2 (E2) included cells from uninjured, sham-operated (abdomen opened) and regenerating (3 days post-amputation) with and without MMP inhibitor (NSC40520) treatment. Cells were obtained by heart dissection followed by enzymatic dissociation and FACS sorting of single, viable nucleated cells.
Project description:The development of alternatives for autologous bone grafts is a major focus of bone tissue engineering. To produce living implants, the use of skeletal stem and progenitor cells (SSPCs) are envisioned as key ingredients. SSPCs can be obtained from bone marrow, adipogenic tissue, dental pulp and periosteum. Human periosteum-derived cells (hPDCs) exhibit a number of progenitor characteristics and have well-documented in vivo bone formation capacity. Here, we have characterized and compared hPDCs derived from tibia with new sources of hPDCs, i.e. from maxilla and mandible (craniofacial hPDCs, as a potential source for tissue engineered implants for craniofacial applications.
Project description:The RSK2 gene is responsible for Coffin-Lowry syndrome, an X-linked monogenic disease associating severe learning deficit andassociated to typical facial and digital abnormalities and skeletal changes. Craniofacial and dental anomalies encountered in this rare disease have been poorly characterized. In this study we explore, through X-Ray microtomographic analysis, the variable craniofacial dysmorphism and dental anomalies present in Rsk2 knockout mice, an animal model of Coffin-Lowry syndrome, as well as in triple Rsk1,2,3 knockout mutants. We report in these mutants the occurrence of a surpernumerary tooth mesial to the first molar. This highly penetrant phenotype is considered as a remnant of evolutionary lost teeth. This possibly leads to the significant reduction of the maxillary diastema. Abnormalities of molar shape were almost restricted to the mesial part of both upper and lower first molars (M1). We also report an expression analysis of the four Rsk genes (Rsk1, 2, 3 and 4) at various stages of odontogenesis in wild-type (WT) mice. Rsk2 was mainly expressed in the mesenchymal, neural crest derived compartment, correlating with proliferative areas of the developing teeth and consistent with a biological function of RSK2 in cell cycle control and cell growth, which when invalidated could be responsible for the dental phenotype. In an attempt to unravel the molecular pathways involved in the genesis of these dental defects, we performed a comparative transcriptomic (DNA microarray) analysis of mandibular wild-type versus Rsk2-/Y molars, and further demonstrated a misregulation of selected genes, using a Rsk2 shRNA knock-down strategy in molar tooth germs cultured in vitro.