ECB-ART-44140
Elife
2015 Jul 28;4. doi: 10.7554/eLife.07343.
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Logics and properties of a genetic regulatory program that drives embryonic muscle development in an echinoderm.
Andrikou C
,
Pai CY
,
Su YH
,
Arnone MI
.
Abstract
Evolutionary origin of muscle is a central question when discussing mesoderm evolution. Developmental mechanisms underlying somatic muscle development have mostly been studied in vertebrates and fly where multiple signals and hierarchic genetic regulatory cascades selectively specify myoblasts from a pool of naive mesodermal progenitors. However, due to the increased organismic complexity and distant phylogenetic position of the two systems, a general mechanistic understanding of myogenesis is still lacking. In this study, we propose a gene regulatory network (GRN) model that promotes myogenesis in the sea urchin embryo, an early branching deuterostome. A fibroblast growth factor signaling and four Forkhead transcription factors consist the central part of our model and appear to orchestrate the myogenic process. The topological properties of the network reveal dense gene interwiring and a multilevel transcriptional regulation of conserved and novel myogenic genes. Finally, the comparison of the myogenic network architecture among different animal groups highlights the evolutionary plasticity of developmental GRNs.
PubMed ID: 26218224
PMC ID: PMC4549668
Article link: Elife
Species referenced: Echinodermata
Genes referenced: ehfl elk1 erg ets1 fgf fgfr3 foxa1 foxc1 foxf1 foxl1 foxy gcml LOC100887844 LOC100890063 LOC100893907 LOC105442066 LOC115918442 LOC115919910 LOC575170 LOC576066 LOC577317 LOC583082 LOC590297 LOC591624 LOC594566 mos pitx2 pole six1 sox9 tbx3l tubgcp2
Antibodies: phospho-elk1 Ab3
Article Images: [+] show captions
Figure 1—figure supplement 1. Three-color FISH of Gcm, Ese, and FoxA.Co-staining of Gcm as a marker for aboral pigment cell precursors, Ese for oral blastocoelar cell precursors, and FoxA for endoderm at 26 hr. Gcm transcript was stained in light green, Ese in red, and FoxA in cyan. Nuclei were labeled blue with DAPI. Yellow circles indicate the SMs, and white circles indicated by white arrows show single cells that do not express any of the analyzed genes. In 85% of the embryos analyzed, approximately two triple-negative cells were observed that might represent myoblast precursors. All embryos are in a vegetal view. Panels A, B, and C are merged confocal stacks, while panels A′–A‴ depict separate channels over DAPI. Panel D is a schematic representation of the vegetal surface of a sea urchin mesenchyme blastula orientated along the oral right/aboral left (O/Ab) axis, seen from the vegetal pole. The different NSM domains identified by distinct regulatory signatures at the vegetal plate are shown in different colors as indicated in the legend. Primary mesenchyme cells are not visible as they have already ingressed into the blastocoel at this stage.DOI: http://dx.doi.org/10.7554/eLife.07343.004 | |
Figure 1—figure supplement 2. Phylogenetic analysis of the sea urchin FGFA protein sequence.(A) The protein domain structure of the SpFGFA contains a signal peptide and a FGF core domain. (B) Phylogenetic analysis of FGF proteins. The tree was constructed by the neighbor-joining method based on the multiple alignments of the FGF core domains from various organisms. Bootstrap values over 50% are shown at the branch points. Sea urchin FGFs (Sp-FgfA and Pl-FgfA) do not group with the seven vertebrate FGF families from A to G. The scale indicates the % amino acid difference with Poisson correction. GenBank accession numbers for FGFs are: acorn worm SkFgf20 like, NM_001171225; amphioxus AmphiFgf1/2, EU606032; AmphiFgf8/17/18, EU606035; AmphiFgf9/16/20, EU606036; ascidian CiFgf8/17/18, NM_001032476; CiFgf11/12/13/14, NM_001032561; Caenorhabditis elegans CeEGL17, NM_075706; Drosophila melanogaster DmPYR, AY55396; DmTHS, NM_136857; human HsFgf19, NM_005117; mouse MmFgf1, NM_010197; MmFgf2, NM_008006; MmFgf3, Y00848; MmFgf4, NM_010202; MmFgf5, NM_010203; MmFgf6, NM_010204; MmFgf7, NM_008008; MmFgf8, NM_010205; MmFgf9, U33535; MmFgf10, NM_008002; MmFgf11, NM_010198; MmFgf12, NM_183064; MmFgf13, NM_010200; MmFgf14, NM_010201; MmFgf15, NM_008003; MmFgf16, AB049219; MmFgf17, NM_008004; MmFgf18, NM_008005; MmFgf20, AB049218; MmFgf21, NM_020013; MmFgf22, NM_023304; MmFgf23, NM_022657; sea urchin Sp-FgfA, HQ107979; Pl-FgfA, EF157978.DOI: http://dx.doi.org/10.7554/eLife.07343.005 | |
Figure 1—figure supplement 3. Phylogenetic analysis of the sea urchin FGFR protein sequences.(A) The protein domain structures of SpFGFR1 and SpFGFR2. The Fibronectin III domain (FN3), three Ig domains (Ig1-3), acid box (AB), transmembrane region (TM), and Tyrosine kinase domain are indicated. (B) For the phylogenetic analysis, the tyrosine kinase domains of FGFRs were aligned, and the tree was built in the same manner as the FGF tree. SpFGFR1 and SpFGFR2 are not orthologous to the human FGFR1 and FGFR2, respectively. GenBank accession numbers for FGFRs are: human HsFgfR1, AB208919; HsFgfR2, NM_000141; HsFgfR3, NM_000142; HsFgfR4, AY892920; ascidian CiFgfR, NM_001044355; C. elegans CeEGL-15, NM_077441; D. melanogaster DmBreathless, NM_168577; DmHeartless, NM_169784; sea urchin SpFgfR1, NM_214537; SpFgfR2, JF499690.DOI: http://dx.doi.org/10.7554/eLife.07343.006 | |
Figure 1—figure supplement 4. Coexpression analysis of FGFR1 and FoxC by double FISH.Relative spatial expression domains of FGFR1 and FoxC at late gastrula stage (48 hr). Image is a stack of merged confocal Z sections in all channels. Inset shows representative single confocal section of the tip of the archenteron. Color code of channel association to each gene is shown in each panel. Nuclei are stained blue with DAPI. Embryo is seen in a frontal view.DOI: http://dx.doi.org/10.7554/eLife.07343.007 | |
Figure 1. Expression analysis of genes encoding sea urchin FGF-signaling components and FoxC by double FISH.FGFR1 and FGF were stained in green and FoxC in red at the very early gastrula stage (30–32 hr). Nuclei were labeled blue with DAPI. Yellow circles indicated by yellow arrowheads show cells co-expressing the analyzed genes. Panels A and B are stacks of merged confocal Z sections of all three channels, while separate channels over DAPI are presented in the other panels. Insets in panels A–A″ show representative single confocal sections to confirm that the two genes are indeed expressed in the same cell. Embryos in A–A″ are seen in a lateral view along the animal-top/vegetal-down axis. Embryos in B–B″ are displayed in a vegetal view. fv, frontal view; vv, vegetal view; o, oral, ab, aboral. The position of the putative unspecified myoblast precursors is indicated in Figure 1—figure supplement 1. Phylogenetic analyses of sea urchin fibroblast growth factor (FGF) and FGFR protein sequences are reported in Figure 1—figure supplements 2, 3, respectively. A co-expression analysis of FGFR1 and FoxC at late gastrula stage (48 hr) is reported in Figure 1—figure supplement 4.DOI: http://dx.doi.org/10.7554/eLife.07343.003 | |
Figure 2—figure supplement 1. Summary of SU5402 and U0126 treatments and MHC protein detection by immunostaining after MEK pathway perturbation.(A) Scheme summarizing the drug treatments performed and the morphological phenotypes observed. (B, C) MHC protein localization was tested by immunostaining in (B) control pluteus larva and (C) pluteus larva treated with the MEK inhibitor U0126 as indicated in (A) by the green line. The ciliary band and gut internal cilia were stained with an anti-acetylated tubulin antibody. MHC was stained in red and acetylated tubulin in green. Nuclei were labeled blue with DAPI. All embryos are seen in lateral view with the oral side on the right.DOI: http://dx.doi.org/10.7554/eLife.07343.009 | |
Figure 2—figure supplement 2. Control experiments for MOs.Panels A- D show control uninjected embryos at very early gastrula (A), late gastrula (B), and pluteus larva (C, D). Panels (E–G) show embryos injected with fluo-control MO at very early gastrula (E), late gastrula (F, H), and pluteus larva (G, I). Panels J and K show the effect in the translation of FGFR1-GFP fusion protein expression after FGFR1 MO injection (K–K′) compared to controls injected with FGFR1-GFP mRNA only (J–J′). A–C, E–G, J and K are bright-field images taken with DIC, E′–G′, J′ and K′ are fluorescent images, whilst D, H, and I are stacks of merged confocal Z sections. In panels D, H, and I, MHC was immunostained in red, acetylated tubulin in green, and nuclei were labeled blue with DAPI. Embryos in panels D and I are the same shown in Figure 2I and Figure 4A, respectively. Embryos in panels A–E, G, and I–K are seen in lateral view while those in panels B, F, and H are in frontal view. fv, frontal view; lv, lateral view; cp, coelomic pouches; pc, pigment cells; sp, spicules; mo, mouth; st, stomach; in, intestine.DOI: http://dx.doi.org/10.7554/eLife.07343.010 | |
Figure 2—figure supplement 3. Immunostaining of P-Elk and expression analysis of genes encoding putative MAPK effectors and FoxC by double FISH.(A, B) Localization of P-Elk protein by immunostaining. (C–F) Spatial expression domains of (C, D) Erg and (E, F) Ets1/2 with respect to FoxC by double FISH. Panels A, B are DIC images, and panels C–F are stacks of merged confocal Z sections. Insets in panels E, F show representative single confocal sections. FoxC is red, Erg is green, and Ets1/2 is cyan. Nuclei were stained blue with DAPI. Embryos in A and C panels are viewed from the vegetal pole while all the others are seen in frontal view.DOI: http://dx.doi.org/10.7554/eLife.07343.011 | |
Figure 2. Perturbation of the FGF pathway.To analyze the phenotype of FGF perturbation, bright-field images were taken with differential interference contrast (DIC). Effects on muscle formation were also tested by detection of MHC expression by fluorescent in situ hybridization (FISH) or of myosin heavy chain (MHC) protein localization by immunostaining on pluteus larvae (72 hr). The ciliary band and gut internal cilia were stained with an anti-acetylated tubulin antibody (AcT). Panels (A–D) show the effect of SU5402 in the formation of the coelomic pouches (B) and MHC expression (D). Panels (E–H) show the effect of anti-FGFR1 translation morpholino oligonucleotide (MO) in the formation of the coelomic pouches, MHC protein localization, and gut morphology. Two representative phenotype embryos, both with impaired muscles while differing for gut sphincter formation, are reported in F (normal gut, 70% of cases) and H (reduced sphincters, 30% of cases). Panels (E, G, I, and J) show the effect in MHC protein localization caused by injection of FGFR1 dominant negative RNA (DnRNA) (J). Panels (A, C) show control embryos treated with DMSO. Panel (G) shows a larva injected with a fluo-control MO and panels (E, I) show control uninjected larvae (for MO injection controls see also ‘Materials and methods’ and Figure 2—figure supplement 2). The inset in panel H is a magnified view of the cilia at the apical organ. Pictures in C, D, and G–J are stacks of merged confocal Z sections. MHC was stained in red and acetylated tubulin in green. Nuclei were labeled blue with DAPI. Spicules are seen in DIC analysis as reflecting polarized light objects. All embryos are seen in frontal view except the ones in panels E, F, and I that are seen in lateral view with the oral side on the right (fv, frontal view; lv, lateral view). White arrows indicate the position of cardiac sphincters, whilst yellow and red arrows show, where present, the pyloric and anal sphincters, respectively. Black lines indicate pigment cells (pc). White lines indicate muscle fibers (mf). The asterisks indicate the absence of coelomic pouches (cp). A summary of SU5402 and U0126 treatments as well as MHC protein expression analysis after MEK pathway perturbation is reported in Figure 2—figure supplement 1. Control MO experiments are reported in Figure 2—figure supplement 2. Co-expression analysis of genes encoding putative MAPK effectors and FoxC as well as P-Elk protein detection is reported in Figure 2—figure supplement 3.DOI: http://dx.doi.org/10.7554/eLife.07343.008 | |
Figure 3. Spatial analysis of gene expression after FGF pathway perturbation by FISH.FoxY (A–D) FoxC (E–H), FoxF (I–L), MHC (I, J), and Ese (A, B) transcript localization tested by FISH in control embryos (A, C, E, G, I, K) and in embryos treated with SU5402 (B, F, J) or injected with FGFR1 MO (D, H, L) (for MO injection controls see also ‘Materials and methods’ and Figure 2—figure supplement 2). Panels A, B, I, and J show double FISH. FoxY was stained in green, FoxC and FoxF in red, MHC in cyan, and Ese in magenta. Nuclei were labeled blue with DAPI. Each picture is a stack of merged confocal Z sections. Yellow circles indicated by yellow arrowheads show cells co-expressing the analyzed genes. The orientation of the larvae is reported for each panel: fv, frontal view; av, animal view; lv, lateral view.DOI: http://dx.doi.org/10.7554/eLife.07343.012 | |
Figure 4—figure supplement 1. Control experiments for MOs.Circumesophagael muscles were tested by phalloidin staining in fluo-control MO-injected pluteus larvae (72 hr) (A, A′) and in embryos of the same age injected with MOs against FoxC (B, B′), FoxF (C, C′), and FoxL1 (D, D′) at different concentrations. Each picture is a stack of merged confocal Z sections. Phalloidin is seen in green and nuclei are labeled blue with Hoechst. All embryos are seen in lateral view with the oral side on the left. Below each panel, statistics of muscle fiber phenotype observed are reported.DOI: http://dx.doi.org/10.7554/eLife.07343.014 | |
Figure 4—figure supplement 2. Co-expression analysis of Six1/2 and FoxC by double FISH.Relative spatial expression domains of Six1/2 and FoxC at the mid gastrula stage (42 hr). Image is a stack of merged confocal Z sections in all channels. Inset shows representative single confocal section of the tip of the archenteron. Color code of channel association to each gene is shown in each panel. Nuclei are stained blue with DAPI. Embryo is seen in a frontal view.DOI: http://dx.doi.org/10.7554/eLife.07343.015 | |
Figure 4—figure supplement 3. The two Six1/2 isoforms.(A) Upstream sequence of the of the Six1/2 gene. Two ATGs are shown in red. The upstream one, highlighted in bold, corresponds to the first ATG in the long isoform (Six1/2N) that is probably generated by an alternative transcription start. The downstream ATG indeed corresponds to the first ATG of the short isoform in which transcription starts a few nucleotides upstream of it (Andrew Ransick, personal communication). Highlighted in different colors show the regions where the different set of qPCR primers were designed: the ones used to amplify the upstream sequence belonging to Six1/2N isoform only, are in yellow, while the ones used to amplify part of the homeobox domain (in bold), common to both isoforms, are highlighted in olive green. The target sequence used to design the MO against the long isoform Six1/2N is highlighted in cyan. (B) Temporal expression profiles of Six1/2 distinct isoforms during sea urchin embryogenesis. Graph shows the number of transcripts per embryo during embryogenesis revealed by qPCR. Six1/2HD represents the sum of the number of transcripts of the two isoforms, while Six1/2N shows only the number of transcripts for Six1/2N. The columns represent average of various measurements, and the error bars are standard deviations. (C, D) Bright-field images were taken with DIC of (C) control uninjected larva and (D) Six1/2N morphant (72 hr) for visualizing the effect on pigmentation.DOI: http://dx.doi.org/10.7554/eLife.07343.016 | |
Figure 4—figure supplement 4. Control experiments for MOs.Circumesophagael muscles were tested by phalloidin staining in fluo-control MO-injected pluteus larvae (72 hr) (A, A′ in Figure 4—figure supplement 1) and in embryos of the same age injected with MOs against Six1/2 (A, A′) and Tbx6 (B, B′) at a concentration of 100 μM. Each picture is a stack of merged confocal Z sections. Phalloidin is seen in green and nuclei are labeled blue with Hoechst. All embryos are seen in lateral view with the oral side on the left. Below each panel, statistics of muscle fiber phenotype observed are reported.DOI: http://dx.doi.org/10.7554/eLife.07343.017 | |
Figure 4. MHC protein detected by immunostaining after perturbation of putative myogenic regulators.MHC protein localization was tested by immunostaining in fluo-control MO-injected pluteus larvae (72 hr) (A) and in embryos of the same age injected with MOs against FoxY (B), FoxC (C), FoxF (D), FoxL1 (E), MyoD2 (F), Six1/2N (G), and Tbx6 (H) (for MO injection controls see also Materials and methods and Figure 2—figure supplement 2). The ciliary band and gut internal cilia were stained by immunohistochemistry with an anti-acetylated tubulin antibody. Each picture is a stack of merged confocal Z sections with MHC in red and acetylated tubulin in green. Nuclei were labeled blue with DAPI. All embryos are seen in lateral view with the oral side on the right. White arrows indicate the position of cardiac sphincters. White lines indicate muscle fibers (mf). Below each panel, statistics of muscle fiber phenotype observed are reported as normal (6–7 mf), mild (4–5 mf), or strong (0–2 mf). A co-expression analysis of Six1/2 and FoxC is reported in Figure 4—figure supplement 1. Analysis of the temporal expression profile of two distinct Six1/2 isoforms and visualization of pigmentation after perturbing Six1/2N isoform are reported in Figure 4—figure supplement 2.DOI: http://dx.doi.org/10.7554/eLife.07343.013 | |
Figure 5. Spatial analysis of gene expression after MO perturbation of selected putative myogenic regulators by FISH.FoxC, FoxY, FoxF, MHC, and nanos transcripts were detected by FISH in fluo-control MO injected embryos (A, C, E, G, I) and in embryos injected with MOs against FoxY (B, D, F), FoxC (H), and FoxF (J). All images are obtained as stacks of merged confocal Z sections. Panels G, H show double FISH. In panel G, single channels over DAPI are shown as insets. FoxY was stained in green, FoxC and FoxF in red, MHC in cyan, and Nanos in magenta. Nuclei were labeled blue with DAPI. Yellow circles indicated by yellow arrowheads show cells co-expressing the analyzed genes. The orientation of the embryos is indicated in each panel: fv, frontal view; lv, lateral view.DOI: http://dx.doi.org/10.7554/eLife.07343.018 | |
Figure 6. Effects of FoxY, FoxC, FoxF, FoxL1, MyoD2, Six1/2, and Tbx6 perturbations on transcript levels of selected mesodermal genes at 44 hr and 48 hr.Each diamond represents a single measurement of three independent biological experiments. Fold differences were calculated between experiments and control counts using the quantitative data obtained from the NanoString nCounter. Onefold change represents no change; ≥ 2 indicates increased expression level significantly (blue labels); ≤ 0.5 indicates decreased expression level significantly (red labels). Asterisks indicate perturbation effects as measured in independent biological experiments by qPCR. NanoString and qPCR perturbation data normalized against controls are provided in Figure 6—source data 1, and raw NanoString data are provided in Figure 6—source data 2.DOI: http://dx.doi.org/10.7554/eLife.07343.01910.7554/eLife.07343.020Figure 6—source data 1. Perturbation data derived from NanoString and qPCR analysis showing fold differences of gene expression in MO-injected embryos after normalization against controls.DOI: http://dx.doi.org/10.7554/eLife.07343.020Figure 6—source data 2. Raw data derived from NanoString analysis.DOI: http://dx.doi.org/10.7554/eLife.07343.021 | |
Figure 7—figure supplement 1. Co-expression analysis of genes encoding mesodermal factors by double FISH.Relative spatial expression domains of (A) SoxE and FoxC at the mid gastrula stage (40 hr), (B) Not and FoxC at the mid gastrula stage (44 hr), and (C) Pitx2 and FoxC at the late gastrula stage (48 hr). Each picture is a stack of merged confocal Z sections in all channels. Inset in panel A shows a representative single confocal section of the tip of the archenteron. Color code of channel association to each gene is shown in each panel. Nuclei are stained blue with DAPI. All embryos are in a frontal view.DOI: http://dx.doi.org/10.7554/eLife.07343.024 | |
Figure 7. Schematic representation and view from all nuclei of the NSM regulatory interactions in early, mid, and late sea urchin gastrulae.On the left side, three developmental stages of the sea urchin embryo are schematized: (A) early, (B) mid, and (C) late gastrula stage. On the right side, the genetic interactions found within this study are summarized. Different colors are used for each domain showing exclusive regulatory states: oral animal non-skeletogenic mesodermal (NSM) (OR AN NSM), salmon pink; NSM, blue; aboral NSM (AB NSM), lavender; small micromere derivatives (SM), green; myogenic domain (M), light red; endoderm (ENDO), yellow-green; oral ectoderm (OR ECTO), light gray. Genes are presented as horizontal thick lines and their names are reported below the thick lines. The wiring among the genes is shown with solid lines, although none of them has been demonstrated to be direct. Arrows represent positive regulation, bars represent repression, and white bullets, together with the dashed lines, indicate signaling events. Genes that are expressed in more than one domain, for which the putative inputs were revealed by NanoString but not validated by spatial expression analysis, are shown on a shaded background. The asterisk in A relates to the fact that we did not demonstrate which FGF factor signals to FGFR1. A co-expression analysis of several genes included in the gene regulatory network (GRN) diagrams is reported in Figure 7—figure supplement 1. Numbers associated to inputs indicate the evidence for all interactions reported and are listed in Figure 7—source data 1.DOI: http://dx.doi.org/10.7554/eLife.07343.02210.7554/eLife.07343.023Figure 7—source data 1. Evidence for all inputs reported in Figure 7.DOI: http://dx.doi.org/10.7554/eLife.07343.023 |
References [+] :
Amin,
A conserved Six-Eya cassette acts downstream of Wnt signaling to direct non-myogenic versus myogenic fates in the C. elegans postembryonic mesoderm.
2009, Pubmed
Amin, A conserved Six-Eya cassette acts downstream of Wnt signaling to direct non-myogenic versus myogenic fates in the C. elegans postembryonic mesoderm. 2009, Pubmed
Amin, The FoxF/FoxC factor LET-381 directly regulates both cell fate specification and cell differentiation in C. elegans mesoderm development. 2010, Pubmed
Andrikou, Myogenesis in the sea urchin embryo: the molecular fingerprint of the myoblast precursors. 2013, Pubmed , Echinobase
Annunziata, A dynamic regulatory network explains ParaHox gene control of gut patterning in the sea urchin. 2014, Pubmed , Echinobase
Balagopalan, Loss-of-function mutations reveal that the Drosophila nautilus gene is not essential for embryonic myogenesis or viability. 2001, Pubmed
Baldauf, A Search for the Origins of Animals and Fungi: Comparing and Combining Molecular Data. 1999, Pubmed
Beh, FoxF is essential for FGF-induced migration of heart progenitor cells in the ascidian Ciona intestinalis. 2007, Pubmed
Beiman, Heartless, a Drosophila FGF receptor homolog, is essential for cell migration and establishment of several mesodermal lineages. 1996, Pubmed
Ben-Tabou de-Leon, Deciphering the underlying mechanism of specification and differentiation: the sea urchin gene regulatory network. 2006, Pubmed , Echinobase
Bentzinger, Building muscle: molecular regulation of myogenesis. 2012, Pubmed
Bertrand, FGF signaling emerged concomitantly with the origin of Eumetazoans. 2014, Pubmed
Bertrand, Amphioxus FGF signaling predicts the acquisition of vertebrate morphological traits. 2011, Pubmed
Bryson-Richardson, The genetics of vertebrate myogenesis. 2008, Pubmed
Burdine, EGL-17(FGF) expression coordinates the attraction of the migrating sex myoblasts with vulval induction in C. elegans. 1998, Pubmed
Burke, Development of the esophageal muscles in embryos of the sea urchin Strongylocentrotus purpuratus. 1988, Pubmed , Echinobase
Burton, Insights from diploblasts; the evolution of mesoderm and muscle. 2008, Pubmed
Ciglar, Conservation and divergence in developmental networks: a view from Drosophila myogenesis. 2009, Pubmed
Davidson, Emerging properties of animal gene regulatory networks. 2010, Pubmed
Davidson, Network design principles from the sea urchin embryo. 2009, Pubmed , Echinobase
Davidson, A genomic regulatory network for development. 2002, Pubmed , Echinobase
Delfini, The timing of emergence of muscle progenitors is controlled by an FGF/ERK/SNAIL1 pathway. 2009, Pubmed
Dorey, FGF signalling: diverse roles during early vertebrate embryogenesis. 2010, Pubmed
Duboc, Nodal and BMP2/4 pattern the mesoderm and endoderm during development of the sea urchin embryo. 2010, Pubmed , Echinobase
Favata, Identification of a novel inhibitor of mitogen-activated protein kinase kinase. 1998, Pubmed
Fernandez-Serra, Role of the ERK-mediated signaling pathway in mesenchyme formation and differentiation in the sea urchin embryo. 2004, Pubmed , Echinobase
Fritzenwanker, The Fox/Forkhead transcription factor family of the hemichordate Saccoglossus kowalevskii. 2014, Pubmed , Echinobase
Gentsch, In vivo T-box transcription factor profiling reveals joint regulation of embryonic neuromesodermal bipotency. 2013, Pubmed
Green, FGF signaling induces mesoderm in the hemichordate Saccoglossus kowalevskii. 2013, Pubmed , Echinobase
Groves, Fgf8 drives myogenic progression of a novel lateral fast muscle fibre population in zebrafish. 2005, Pubmed
Hannenhalli, The evolution of Fox genes and their role in development and disease. 2009, Pubmed
Hibino, Phylogenetic correspondence of the body axes in bilaterians is revealed by the right-sided expression of Pitx genes in echinoderm larvae. 2006, Pubmed , Echinobase
Hibino, Ion flow regulates left-right asymmetry in sea urchin development. 2006, Pubmed , Echinobase
Howard-Ashby, Gene families encoding transcription factors expressed in early development of Strongylocentrotus purpuratus. 2006, Pubmed , Echinobase
Itoh, Fibroblast growth factors: from molecular evolution to roles in development, metabolism and disease. 2011, Pubmed
Juliano, Germ line determinants are not localized early in sea urchin development, but do accumulate in the small micromere lineage. 2006, Pubmed , Echinobase
Ko, Levels of circulating selenoprotein P, fibroblast growth factor (FGF) 21 and FGF23 in relation to the metabolic syndrome in young children. 2014, Pubmed
Lapraz, RTK and TGF-beta signaling pathways genes in the sea urchin genome. 2006, Pubmed , Echinobase
Lee, Exclusive developmental functions of gatae cis-regulatory modules in the Strongylocentrorus purpuratus embryo. 2007, Pubmed , Echinobase
Lo, Different isoforms of the C. elegans FGF receptor are required for attraction and repulsion of the migrating sex myoblasts. 2008, Pubmed
Luo, Opposing nodal and BMP signals regulate left-right asymmetry in the sea urchin larva. 2012, Pubmed , Echinobase
Macneil, Gene regulatory networks and the role of robustness and stochasticity in the control of gene expression. 2011, Pubmed
Mahlapuu, The forkhead transcription factor Foxf1 is required for differentiation of extra-embryonic and lateral plate mesoderm. 2001, Pubmed
Marcelle, Coordinate actions of BMPs, Wnts, Shh and noggin mediate patterning of the dorsal somite. 1997, Pubmed
Marics, FGFR4 signaling is a necessary step in limb muscle differentiation. 2002, Pubmed
Materna, High accuracy, high-resolution prevalence measurement for the majority of locally expressed regulatory genes in early sea urchin development. 2010, Pubmed , Echinobase
Materna, A protocol for unraveling gene regulatory networks. 2008, Pubmed , Echinobase
Materna, Notch and Nodal control forkhead factor expression in the specification of multipotent progenitors in sea urchin. 2013, Pubmed , Echinobase
Materna, Diversification of oral and aboral mesodermal regulatory states in pregastrular sea urchin embryos. 2013, Pubmed , Echinobase
Materna, A comprehensive analysis of Delta signaling in pre-gastrular sea urchin embryos. 2012, Pubmed , Echinobase
Mazet, An ancient Fox gene cluster in bilaterian animals. 2006, Pubmed
McCoon, SpFGFR, a new member of the fibroblast growth factor receptor family, is developmentally regulated during early sea urchin development. 1996, Pubmed , Echinobase
Minokawa, Expression patterns of four different regulatory genes that function during sea urchin development. 2004, Pubmed , Echinobase
Mohammadi, Structures of the tyrosine kinase domain of fibroblast growth factor receptor in complex with inhibitors. 1997, Pubmed
Molkentin, Combinatorial control of muscle development by basic helix-loop-helix and MADS-box transcription factors. 1996, Pubmed
Muha, Functions and Mechanisms of Fibroblast Growth Factor (FGF) Signalling in Drosophila melanogaster. 2013, Pubmed
Naiche, FGF4 and FGF8 comprise the wavefront activity that controls somitogenesis. 2011, Pubmed
Neugebauer, FGF signaling is required for brain left-right asymmetry and brain midline formation. 2014, Pubmed
Oki, Dissecting the role of Fgf signaling during gastrulation and left-right axis formation in mouse embryos using chemical inhibitors. 2010, Pubmed
Oliveri, Gene regulatory network controlling embryonic specification in the sea urchin. 2004, Pubmed , Echinobase
Olson, bHLH factors in muscle development: dead lines and commitments, what to leave in and what to leave out. 1994, Pubmed
Peter, A gene regulatory network controlling the embryonic specification of endoderm. 2011, Pubmed , Echinobase
Poustka, A global view of gene expression in lithium and zinc treated sea urchin embryos: new components of gene regulatory networks. 2007, Pubmed , Echinobase
Ransick, Cis-regulatory logic driving glial cells missing: self-sustaining circuitry in later embryogenesis. 2012, Pubmed , Echinobase
Ransick, cis-regulatory processing of Notch signaling input to the sea urchin glial cells missing gene during mesoderm specification. 2006, Pubmed , Echinobase
Ransick, New early zygotic regulators expressed in endomesoderm of sea urchin embryos discovered by differential array hybridization. 2002, Pubmed , Echinobase
Rast, Recovery of developmentally defined gene sets from high-density cDNA macroarrays. 2000, Pubmed , Echinobase
Rizzo, Identification and developmental expression of the ets gene family in the sea urchin (Strongylocentrotus purpuratus). 2006, Pubmed , Echinobase
Ruffins, A fate map of the vegetal plate of the sea urchin (Lytechinus variegatus) mesenchyme blastula. 1996, Pubmed , Echinobase
Röttinger, FGF signals guide migration of mesenchymal cells, control skeletal morphogenesis [corrected] and regulate gastrulation during sea urchin development. 2008, Pubmed , Echinobase
Sandhu, Fibroblast growth factor signaling in liver carcinogenesis. 2014, Pubmed
Seipel, Evolution of striated muscle: jellyfish and the origin of triploblasty. 2005, Pubmed
Sherwood, LvNotch signaling mediates secondary mesenchyme specification in the sea urchin embryo. 1999, Pubmed , Echinobase
Shimeld, Clustered Fox genes in lophotrochozoans and the evolution of the bilaterian Fox gene cluster. 2010, Pubmed
Shimeld, Evolutionary genomics of the Fox genes: origin of gene families and the ancestry of gene clusters. 2010, Pubmed
Solek, An ancient role for Gata-1/2/3 and Scl transcription factor homologs in the development of immunocytes. 2013, Pubmed , Echinobase
Song, The forkhead transcription factor FoxY regulates Nanos. 2012, Pubmed , Echinobase
Steinmetz, Independent evolution of striated muscles in cnidarians and bilaterians. 2012, Pubmed
Sweet, LvDelta is a mesoderm-inducing signal in the sea urchin embryo and can endow blastomeres with organizer-like properties. 2002, Pubmed , Echinobase
Tokuoka, FGF9/16/20 and Wnt-5alpha signals are involved in specification of secondary muscle fate in embryos of the ascidian, Halocynthia roretzi. 2007, Pubmed
Tu, Sea urchin Forkhead gene family: phylogeny and embryonic expression. 2006, Pubmed , Echinobase
Vasyutina, Notch function in myogenesis. 2007, Pubmed
Walton, Hedgehog signaling patterns mesoderm in the sea urchin. 2009, Pubmed , Echinobase
Wang, Notch signaling and Notch signaling modifiers. 2011, Pubmed
Warner, Hedgehog signaling requires motile cilia in the sea urchin. 2014, Pubmed , Echinobase
Wilm, The forkhead genes, Foxc1 and Foxc2, regulate paraxial versus intermediate mesoderm cell fate. 2004, Pubmed
Wu, Twist is an essential regulator of the skeletogenic gene regulatory network in the sea urchin embryo. 2008, Pubmed , Echinobase
Yokoyama, The myogenic transcriptional network. 2011, Pubmed
Zinzen, Combinatorial binding predicts spatio-temporal cis-regulatory activity. 2009, Pubmed