A5078692545- Developmental Biology and Gene Regulation
- Echinoderm biology and ecology
- Wnt/β-catenin signaling in development and cancer
- Marine and coastal plant biology
- Insect and Arachnid Ecology and Behavior
- Marine Ecology and Invasive Species
- Plant and animal studies
- Animal Behavior and Reproduction
- Cancer-related gene regulation
- Ocean Acidification Effects and Responses
- Congenital heart defects research
- Environmental and Biological Research in Conflict Zones
- Cephalopods and Marine Biology
- Agriculture and Biological Studies
- Genetic diversity and population structure
- Lepidoptera: Biology and Taxonomy
- TGF-β signaling in diseases
- Morphological variations and asymmetry
- Sperm and Testicular Function
- Insect Resistance and Genetics
- Congenital limb and hand anomalies
- Bone Metabolism and Diseases
- interferon and immune responses
- Polyamine Metabolism and Applications
- Epigenetics and DNA Methylation
Auburn University
2011-2024
Mississippi State University
2014-2018
National Institute of Dental and Craniofacial Research
2006-2016
National Institutes of Health
2006-2016
Centre National de la Recherche Scientifique
2006-2011
Sorbonne Université
2006-2011
Laboratoire d’Océanographie de Villefranche
2007-2010
Duke University
2000-2008
California Institute of Technology
2006
Baylor College of Medicine
2006
Echinoderms, which are phylogenetically related to vertebrates and produce large numbers of transparent embryos that can be experimentally manipulated, offer many advantages for the analysis gene regulatory networks (GRN) regulating germ layer formation. During development sea urchin embryo, ectoderm is source signals pattern all three layers along dorsal-ventral axis. How this signaling center controls patterning morphogenesis embryo not understood. Here, we report a large-scale GRN...
Three different Wnt signaling pathways function to restrict the anterior neuroectoderm state end of sea urchin embryo, a mechanism fate restriction that could be conserved among deuterostomes.
The TGF-β family member Nodal is essential for specification of the dorsal-ventral axis sea urchin embryo, but molecular factors regulating its expression are not known. Analysis nodalpromoter an excellent entry point to identify these and dissect regulatory logic driving specification. Using phylogenetic footprinting, we delineated two regions located in 5′ region nodal promoter intron that required correct spatial autoregulation. 5′regulatory contains binding sites homeodomain, bZIP,...
At fourth cleavage of sea urchin embryos four micromeres at the vegetal pole separate from macromeres just above them in an unequal cleavage. The have capacity to induce a second axis if transplanted animal and absence results failure macromere progeny specify secondary mesenchyme cells (SMCs). This suggests that SMCs. We demonstrate require nuclear beta-catenin exhibit SMC induction activity. Transplantation studies show much hemisphere is competent receive signal. SMCs, most likely through...
In the sea urchin, entry of β-catenin into nuclei vegetal cells at 4th and 5th cleavages is necessary for activation endomesoderm gene regulatory network. Beyond that, little known about how embryo uses maternal information to initiate specification. Here, experiments establish that three Wnts in egg, Wnt6 endodermal genes GRN. A small region cortex shown be If cortical egg removed, addition rescues endoderm. At a molecular level, contains localized concentration Dishevelled (Dsh) protein,...
The segregation of embryonic endomesoderm into separate endoderm and mesoderm fates is not well understood in deuterostomes. Using sea urchin embryos, we showed that Notch signaling initiates the precursor field by inhibiting expression a key transcription factor presumptive mesoderm. regulatory circuit activated this subsequently maintains canonical Wnt (cWnt) ligand only precursors. This cWnt reinforces state, amplifying distinction between emerging Before gastrulation, Notch-dependent...
Anterior signaling centers are essential to specify and pattern the early anterior neuroectoderm (ANE) of many deuterostome embryos. In sea urchin embryo ANE is restricted end late blastula-stage where it forms a simple neural territory consisting several types neurons, as well apical tuft. Here, we show that during development, separates into inner outer regulatory domains expressing cardinal transcriptional regulators, FoxQ2 Six3, respectively. drives this patterning process, which...
The anterior neuroectoderm (ANE) in many deuterostome embryos (echinoderms, hemichordates, urochordates, cephalochordates, and vertebrates) is progressively restricted along the anterior-posterior axis to a domain around pole. In sea urchin embryo, three integrated Wnt signaling branches (Wnt/β-catenin, Wnt/JNK, Wnt/PKC) govern this progressive restriction process, which begins 32- 60-cell stage terminates by early gastrula stage. We previously have established that several secreted...
Wnt genes are major developmental highly conserved across all animals. Yet, our understanding of the gene repertoire and their functions is still largely incomplete. In Lepidoptera, have been implicated in wing pattern development. For example, WntA has shown as a driver diversification nymphalid butterflies. this study we characterize Zerene cesonia (Family: Pieridae), which diverged from nymphalids ~51 million years ago, to determine if may role development distant butterfly lineages. We...
Abstract Sexually dimorphic development is responsible for some of the most remarkable phenotypic variation found in nature. Alternative splicing transcription factor gene doublesex (dsx) a highly conserved developmental switch controlling expression sex-specific pathways. Here, we leverage differences butterfly wing color pattern to characterize genetic basis sexually development. We use RNA-seq, immunolocalization, and motif binding site analysis test specific predictions about role dsx...
Wnt and Nodal signaling pathways are required for initial patterning of cell fates along anterior-posterior (AP) dorsal-ventral (DV) axes, respectively, sea urchin embryos during cleavage early blastula stages. These mechanisms connected because expression nodal depends on Wnt/β-catenin signaling. Here, we show that an important subsequent function is to control the shape domain maintain correct specification different types axes embryo. In absence Wnt1, posterior-ventral region embryo...
Activation of the Notch signaling pathway segregates non-skeletogenic mesoderm (NSM) from endomesoderm during sea urchin embryo development. Subsequently, helps specify four subpopulations NSM, and influences endoderm specification. To gain further insight into how is regulated these cell specification events, we identified a homologue Numb (LvNumb). Previous work in other model systems showed that functions as antagonist, possibly by mediating endocytosis key interacting proteins. In this...
Studies across a diverse group of metazoan embryos indicate that Wnt signaling often activates the transcription factor Sp5, forming 'cassette' plays critical roles in many developmental processes. This study explores role Wnt/Sp5 during specification and patterning primary germ layers early anterior-posterior axis formation deuterostome sea urchin embryo. Our functional analyses show Sp5 is for endomesoderm downstream Wnt/β-catenin posterior cells as well anterior neuroectoderm...
Synopsis How animal body plans evolved and diversified is a major question in evolutionary developmental biology. To address this question, it important to characterize the exact molecular mechanisms that establish embryonic axes give rise adult plan. The anterior–posterior (AP) axis first be established most embryos, echinoderm sea urchin embryos its formation governed by an integrated network of three different Wnt signaling pathways: Wnt/β-catenin, Wnt/JNK, Wnt/PKC pathways. extent which...
In the sea urchin embryo, specification of dorsal-ventral axis critically relies on spatially restricted expression nodal in presumptive ventral ectoderm. The restriction requires activity maternal TGF-β ligand Panda but mechanism by which restricts is unknown. Similarly, what initiates ectoderm and are mechanisms that link patterning along primary secondary axes not well understood. We report Paracentrotus lividus, maternally expressed ETS-domain transcription factor Yan/Tel essential for...
A Wnt signaling network governs early anterior-posterior (AP) specification and patterning of the deuterostome sea urchin embryo. We have previously shown that non-canonical Fzl1/2/7 antagonizes progressive posterior-to-anterior downregulation anterior neuroectoderm (ANE) gene regulatory (GRN) by canonical Wnt/β-catenin Wnt1/Wnt8-Fzl5/8-JNK signaling. This study focuses on function Wnt16 ligand during AP patterning. Maternally supplied
Gene silencing by feeding double-stranded (dsRNA) holds promise as a novel pest management strategy. Nonetheless, degradation of dsRNA in the environment and within insect gut, well inefficient systemic delivery are major limitations to applying this Branched amphiphilic peptide capsules (BAPCs) complexed with have been used successfully target genes outside inside gut epithelium upon ingestion. This suggests that BAPCs can protect from shuttle it across epithelium. In study, our objectives...
A combination of receptors, co-receptors, and secreted Wnt modulators form protein complexes at the cell surface that activate one or more three different signaling pathways (Wnt/β-catenin, Wnt/JNK, Wnt/Ca2+). Two these are often active in same cellular territories, forming networks; however, molecular mechanisms necessary to integrate information from situations unclear any vivo model system. Recent studies have implicated two binding receptor tyrosine kinases, kinase-like orphan (Ror)...
Remarkably few cell-to-cell signal transduction pathways are necessary during embryonic development to generate the large variety of cell types and tissues in adult body form. Yet, each year more components individual signaling discovered, studies indicate that depending on context there is significant cross-talk among most these pathways. This complexity makes studying any vivo developmental model system a difficult task. In addition, efficient functional analyses required characterize...