Project description:To begin identifying potential downstream of BMP signaling involved in midline facial development, we conducted a transcriptome analysis comparing the expression profiles of control versus ca-Acvr1(A11);P0-Cre nasal process tissues.
Project description:The BMP signaling pathway regulates multiple steps of hematopoiesis, mediated through receptor-regulated Smads, including Smad1 and Smad5. Here we use loss-of-function approaches in zebrafish to compare the roles of Smad1 and Smad5 during embryonic hematopoiesis. Microarray experiments revealed that the two proteins regulate redundantly the key initiators of the hemato-vascular program, including scl, lmo2, and gfi1. However, each also regulates a remarkably distinct genetic program, with Smad5 uniquely regulating the BMP signaling pathway itself. Our results suggest that specificity of BMP signaling output, with respect to hematopoiesis, can be explained by differential functions of Smad1 and Smad5. Keywords: Gene expression transcript profiles The experiment was designed to identify the unique Smad1 and Smad5 dependent transcripts during the somitogenesis stage of development, during which mesoderm is specified to the hematopoietic lineage. Embryos were injected with translational blocking morpholinos for Smad1, Smad5 or both, and then collected at the 1-somite stage for RNA extraction. For every experiment control uninjected wildtype sibling embryo were also collected for comparison. Three biological replicates were done for each knockdown set. Total RNA was sent to Nimblegen for cDNA synthesis, dye labeling and hybridization. Single knockdown samples were hybridized to the Nimblegen 2006 Danio rerio Gene Expression Array chip and the double knockdown samples to the 2007 verison of the chip, which contains the same test genes, but with additional control oligos. Dye swaps were done for each set; for 2 of the 3 hybridization in each set Cy3 was the dye used for the experimental sample and in the 3rd Cy5 was used. The raw hybridization data was obtained from Nimblegen, normalized using NimbleScan and anaylzed using R software.
Project description:The BMP signaling pathway regulates multiple steps of hematopoiesis, mediated through receptor-regulated Smads, including Smad1 and Smad5. Here we use loss-of-function approaches in zebrafish to compare the roles of Smad1 and Smad5 during embryonic hematopoiesis. Microarray experiments revealed that the two proteins regulate redundantly the key initiators of the hemato-vascular program, including scl, lmo2, and gfi1. However, each also regulates a remarkably distinct genetic program, with Smad5 uniquely regulating the BMP signaling pathway itself. Our results suggest that specificity of BMP signaling output, with respect to hematopoiesis, can be explained by differential functions of Smad1 and Smad5. Keywords: Gene expression transcript profiles
Project description:The specification of cartilage requires Sox9, a transcription factor with broad roles for organogenesis outside the skeletal system. How Sox9 gains selective access to cartilage-specific cis-regulatory regions during skeletal development had remained unclear. By analyzing chromatin accessibility during the differentiation of neural crest cells into chondrocytes of the zebrafish head, we find that cartilage-associated chromatin accessibility is dynamically established. Cartilage-associated regions that become accessible after neural crest migration are co-enriched for Sox9 and Fox transcription factor binding motifs. In zebrafish lacking Foxc1 paralogs, we find a global decrease in chromatin accessibility in chondrocytes, consistent with a later loss of dorsal facial cartilages. Zebrafish transgenesis assays confirm that many of these Foxc1-dependent elements function as enhancers with region- and stage-specific activity in facial cartilages. We propose that Foxc1-dependent chromatin accessibility helps directs the versatile Sox9 protein to a chondrogenic program in the face.
Project description:Non-syndromic facial asymmetry is commonly found in dentofacial deformity populations with skeletal malocclusions. Asymmetry of this type may result from imbalanced growth and function of both the jaw and associated muscles. Among the multiple genes that interact to affect the craniofacial musculoskeletal complex during pre and postnatal growth and development, NODAL signaling pathwy (NSP) genes are active in adult skeletal muscle and may be key factors in development, growth and maintenance of facial asymmetry. It is of interest to determine whether expression of NODAL pathway genes might differ in masseter muscles between individuals with malocclusion that have facial asymmetry and normal symmetry. Human Transcriptome 2.0 GeneChips (HTA2.0) were used to examine global gene expression in masster muscles between malocclusion subjects with posterior facial asymmetry and with normal facial symmetry.
Project description:Conditional Bmp4 overexpression (Bmp4 OE), using a tetracycline regulated Bmp4 gain of function allele, resulted in facial skeletal changes that were most dramatic after an E10.5 Bmp4 induction. We identified a number of genes predominantly transcriptional regulators controlling self-renewal, osteoblast differentiation, and negative Bmp autoregulation whose expression were change after Bmp4 overexpression in the cranial neural crest cells.
Project description:Bone morphogenetic proteins (BMPs) regulate many aspects of skeletal development, including osteoblast and chondrocyte differentiation, cartilage and bone formation, and cranial and limb development. Among them, BMP2, one of the most potent osteogenic signaling molecules, stimulates osteoblast differentiation. We used cDNA microarrays to elucidate regulators of BMP-2-induced osteoblast differentiation.
Project description:The mechanism for human germ-cell specification, which sets out a complex program generating spermatozoa or oocytes, remains largely unknown. We established a system for inducing human primordial germ cell-like cells (hPGCLCs) from induced pluripotent stem cells (hiPSCs) via incipient mesoderm-like cells (iMeLCs). Here, we show that EOMESODERMIN (EOMES) elevates in iMeLCs through WNT signaling and is essential for activating SOX17, a key driver for hPGC(LC) specification, with the duration/dosage of the WNT signaling/EOMES expression dictating the germ-cell competence. Upon hPGCLC induction, BMP signaling activates TFAP2C independently from SOX17, and SOX17 and TFAP2C instate the hPGCLC program, including BLIMP1 expression, in an interdependent fashion. The hPGC(LC) specification program is highly consistent with the monkey program, but is divergent from the mouse one regarding key transcription factors and their hierarchy of actions. These findings delineate evolutionary divergence of mammalian germ-cell specification, providing a foundation for further human germ-cell development in vitro.
Project description:Bone morphogenetic proteins (BMPs) regulate many aspects of skeletal development, including osteoblast and chondrocyte differentiation, cartilage and bone formation, and cranial and limb development. Among them, BMP2, one of the most potent osteogenic signaling molecules, stimulates osteoblast differentiation, while it inhibits myogenic differentiation in C2C12 cells. We used cDNA microarrays to elucidate regulators of BMP-2-induced osteoblast differentiation.