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Carolyn L Smith - One of the best experts on this subject based on the ideXlab platform.
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Microscopy Studies of Placozoans.
Methods in molecular biology (Clifton N.J.), 2020Co-Authors: Carolyn L Smith, Thomas S. Reese, Tatiana D. Mayorova, Christine A. Winters, Sally P. Leys, Andreas HeylandAbstract:Trichoplax adhaerens is an enigmatic animal with an extraordinarily simple morphology and a cellular organization, which are the focus of current research. Protocols outlined here provide detailed descriptions of advanced techniques for light and electron microscopic studies of Trichoplax. Studies using these techniques have enhanced our understanding of cell type diversity and function in placozoans and have provided insight into the evolution, development, and physiology of this little understood group.
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a na leak channel cloned from Trichoplax adhaerens extends extracellular ph and ca2 sensing for the deg enac family close to the base of metazoa
Journal of Biological Chemistry, 2019Co-Authors: Wassim Elkhatib, Carolyn L Smith, Adriano SenatoreAbstract:Acid-sensitive ion channels belonging to the degenerin/epithelial sodium channel (DEG/ENaC) family activate in response to extracellular protons and are considered unique to deuterostomes. However, sensitivity to pH/protons is more widespread, where, for example, human ENaC Na+ leak channels are potentiated and mouse BASIC and Caenorhabditis elegans ACD-1 Na+ leak channels are blocked by extracellular protons. For many DEG/ENaC channels, extracellular Ca2+ ions modulate gating, and in some cases, the binding of protons and Ca2+ is interdependent. Here, we functionally characterize a DEG/ENaC channel from the early-diverging animal Trichoplax adhaerens, TadNaC6, that conducts Na+-selective leak currents in vitro sensitive to blockade by both extracellular protons and Ca2+. We determine that proton block is enhanced in low external Ca2+ concentration, whereas calcium block is enhanced in low external proton concentration, indicative of competitive binding of these two ligands to extracellular sites of the channel protein. TadNaC6 lacks most determinant residues for proton and Ca2+ sensitivity in other DEG/ENaC channels, and a mutation of one conserved residue (S353A) associated with Ca2+ block in rodent BASIC channels instead affected proton sensitivity, all indicative of independent evolution of H+ and Ca2+ sensitivity. Strikingly, TadNaC6 was potently activated by the general DEG/ENaC channel blocker amiloride, a rare feature only reported for the acid-activated channel ASIC3. The sequence and structural divergence of TadNaC6, coupled with its noncanonical functional features, provide unique opportunities for probing the proton, Ca2+, and amiloride regulation of DEG/ENaC channels and insight into the possible core-gating features of ancestral ion channels.
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A Na+ leak channel cloned from Trichoplax adhaerens extends extracellular pH and Ca2+ sensing for the DEG/ENaC family close to the base of Metazoa.
The Journal of biological chemistry, 2019Co-Authors: Wassim Elkhatib, Carolyn L Smith, Adriano SenatoreAbstract:Acid-sensitive ion channels belonging to the degenerin/epithelial sodium channel (DEG/ENaC) family activate in response to extracellular protons and are considered unique to deuterostomes. However, sensitivity to pH/protons is more widespread, where, for example, human ENaC Na+ leak channels are potentiated and mouse BASIC and Caenorhabditis elegans ACD-1 Na+ leak channels are blocked by extracellular protons. For many DEG/ENaC channels, extracellular Ca2+ ions modulate gating, and in some cases, the binding of protons and Ca2+ is interdependent. Here, we functionally characterize a DEG/ENaC channel from the early-diverging animal Trichoplax adhaerens, TadNaC6, that conducts Na+-selective leak currents in vitro sensitive to blockade by both extracellular protons and Ca2+ We determine that proton block is enhanced in low external Ca2+ concentration, whereas calcium block is enhanced in low external proton concentration, indicative of competitive binding of these two ligands to extracellular sites of the channel protein. TadNaC6 lacks most determinant residues for proton and Ca2+ sensitivity in other DEG/ENaC channels, and a mutation of one conserved residue (S353A) associated with Ca2+ block in rodent BASIC channels instead affected proton sensitivity, all indicative of independent evolution of H+ and Ca2+ sensitivity. Strikingly, TadNaC6 was potently activated by the general DEG/ENaC channel blocker amiloride, a rare feature only reported for the acid-activated channel ASIC3. The sequence and structural divergence of TadNaC6, coupled with its noncanonical functional features, provide unique opportunities for probing the proton, Ca2+, and amiloride regulation of DEG/ENaC channels and insight into the possible core-gating features of ancestral ion channels.
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Insights into the evolution of digestive systems from studies of Trichoplax adhaerens
Cell and Tissue Research, 2019Co-Authors: Carolyn L Smith, T. D. MayorovaAbstract:Trichoplax , a member of the phylum Placozoa, is a tiny ciliated marine animal that glides on surfaces feeding on algae and cyanobacteria. It stands out from other animals in that it lacks an internal digestive system and, instead, digests food trapped under its lower surface. Here we review recent work on the phenotypes of its six cell types and their roles in digestion and feeding behavior. Phylogenomic analyses place Placozoa as sister to Eumetazoa, the clade that includes Cnidaria and Bilateria. Comparing the phenotypes of cells in Trichoplax to those of cells in the digestive epithelia of Eumetazoa allows us to make inferences about the cell types and mode of feeding of their ancestors. From our increasingly mechanistic understanding of feeding in Trichoplax , we get a glimpse into how primitive animals may have hunted and consumed food prior to the evolution of neurons, muscles, and internal digestive systems.
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The ventral epithelium of Trichoplax adhaerens deploys in distinct patterns cells that secrete digestive enzymes, mucus or diverse neuropeptides.
Biology open, 2019Co-Authors: Tatiana D. Mayorova, Thomas S. Reese, Katherine Hammar, Christine A. Winters, Carolyn L SmithAbstract:The disk-shaped millimeter-sized marine animal, Trichoplax adhaerens, is notable because of its small number of cell types and primitive mode of feeding. It glides on substrates propelled by beating cilia on its lower surface and periodically pauses to feed on underlying microorganisms, which it digests externally. Here, a combination of advanced electron and light microscopic techniques are used to take a closer look at its secretory cell types and their roles in locomotion and feeding. We identify digestive enzymes in lipophils, a cell type implicated in external digestion and distributed uniformly throughout the ventral epithelium except for a narrow zone near its edge. We find three morphologically distinct types of gland cell. The most prevalent contains and secretes mucus, which is shown to be involved in adhesion and gliding. Half of the mucocytes are arrayed in a tight row around the edge of the ventral epithelium while the rest are scattered further inside, in the region containing lipophils. The secretory granules in mucocytes at the edge label with an antibody against a neuropeptide that was reported to arrest ciliary beating during feeding. A second type of gland cell is arrayed in a narrow row just inside the row of mucocytes while a third is located more centrally. Our maps of the positions of the structurally distinct secretory cell types provide a foundation for further characterization of the multiple peptidergic cell types in Trichoplax and the microscopic techniques we introduce provide tools for carrying out these studies.
Adriano Senatore - One of the best experts on this subject based on the ideXlab platform.
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Conserved biophysical features of the CaV2 presynaptic Ca2+ channel homologue from the early-diverging animal Trichoplax adhaerens
The Journal of biological chemistry, 2020Co-Authors: Julia Gauberg, Wassim Elkhatib, Thomas Piekut, Salsabil Abdallah, Alicia N. Harracksingh, Elise F. Stanley, Adriano SenatoreAbstract:The dominant role of CaV2 voltage-gated calcium channels for driving neurotransmitter release is broadly conserved. Given the overlapping functional properties of CaV2 and CaV1 channels, and less so CaV3 channels, it is unclear why there have not been major shifts towards dependency on other CaV channels for synaptic transmission. Here, we provide a structural and functional profile of the CaV2 channel cloned from the early-diverging animal Trichoplax adhaerens, which lacks a nervous system but possess single gene homologues for CaV1-CaV3 channels. Remarkably, the highly divergent channel possesses similar features as human CaV2.1 and other CaV2 channels, including high voltage-activated currents that are larger in external Ba2+ than Ca2+, voltage dependent kinetics of activation, inactivation and deactivation, and bimodal recovery from inactivation. Altogether, the functional profile of Trichoplax CaV2 suggests that the core features of pre-synaptic CaV2 channels were established early during animal evolution, after CaV1 and CaV2 channels emerged via proposed gene duplication from an ancestral CaV1/2 type channel. The Trichoplax channel was relatively insensitive to mammalian CaV2 channel blockers ω-agatoxin-IVA and ω-conotoxin-GVIA, and to metal cation blockers Cd2+ and Ni2+ Also absent was the capacity for voltage-dependent G-protein inhibition by co-expressed Trichoplax Gβγ subunits, which nevertheless inhibited the human CaV2.1 channel suggesting that this modulatory capacity evolved via changes in channel sequence/structure, and not G-proteins. Lastly, the Trichoplax channel was immunolocalized in cells that express an endomorphin-like peptide implicated in cell signaling and locomotive behavior, and other likely secretory cells, suggesting contributions to regulated exocytosis.
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conserved biophysical features of the cav2 presynaptic ca2 channel homologue from the early diverging animal Trichoplax adhaerens
Journal of Biological Chemistry, 2020Co-Authors: Julia Gauberg, Wassim Elkhatib, Thomas Piekut, Salsabil Abdallah, Alicia N. Harracksingh, Elise F. Stanley, Adriano SenatoreAbstract:The dominant role of CaV2 voltage-gated calcium channels for driving neurotransmitter release is broadly conserved. Given the overlapping functional properties of CaV2 and CaV1 channels, and less so CaV3 channels, it is unclear why there have not been major shifts toward dependence on other CaV channels for synaptic transmission. Here, we provide a structural and functional profile of the CaV2 channel cloned from the early-diverging animal Trichoplax adhaerens, which lacks a nervous system but possesses single gene homologues for CaV1-CaV3 channels. Remarkably, the highly divergent channel possesses similar features as human CaV2.1 and other CaV2 channels, including high voltage-activated currents that are larger in external Ba2+ than in Ca2+; voltage-dependent kinetics of activation, inactivation, and deactivation; and bimodal recovery from inactivation. Altogether, the functional profile of Trichoplax CaV2 suggests that the core features of presynaptic CaV2 channels were established early during animal evolution, after CaV1 and CaV2 channels emerged via proposed gene duplication from an ancestral CaV1/2 type channel. The Trichoplax channel was relatively insensitive to mammalian CaV2 channel blockers ω-agatoxin-IVA and ω-conotoxin-GVIA and to metal cation blockers Cd2+ and Ni2+. Also absent was the capacity for voltage-dependent G-protein inhibition by co-expressed Trichoplax Gβγ subunits, which nevertheless inhibited the human CaV2.1 channel, suggesting that this modulatory capacity evolved via changes in channel sequence/structure, and not G proteins. Last, the Trichoplax channel was immunolocalized in cells that express an endomorphin-like peptide implicated in cell signaling and locomotive behavior and other likely secretory cells, suggesting contributions to regulated exocytosis.
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Functional Studies of Trichoplax adhaerens Voltage-Gated Calcium Channel Activity.
Methods in molecular biology (Clifton N.J.), 2020Co-Authors: Julia Gauberg, Adriano Senatore, Andreas HeylandAbstract:Trichoplax adhaerens is a member of the phylum Placozoa, an enigmatic group of benthic animals with remarkably simple morphology. While initial work on these organisms has primarily focused on their morphology and the development of genomic resources, Trichoplax has received increased attention as a model for studying the evolution of nervous and sensory systems. This work is motivated by the fact that Trichoplax features distinct behaviours and responses to environmental stimuli. Therefore, much progress has been made in recent years on the molecular, cellular, and behavioral understanding of this organism. Methods outlined here provide hands-on approaches to cutting edge molecular and cellular techniques to record cellular activities in Trichoplax.
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a na leak channel cloned from Trichoplax adhaerens extends extracellular ph and ca2 sensing for the deg enac family close to the base of metazoa
Journal of Biological Chemistry, 2019Co-Authors: Wassim Elkhatib, Carolyn L Smith, Adriano SenatoreAbstract:Acid-sensitive ion channels belonging to the degenerin/epithelial sodium channel (DEG/ENaC) family activate in response to extracellular protons and are considered unique to deuterostomes. However, sensitivity to pH/protons is more widespread, where, for example, human ENaC Na+ leak channels are potentiated and mouse BASIC and Caenorhabditis elegans ACD-1 Na+ leak channels are blocked by extracellular protons. For many DEG/ENaC channels, extracellular Ca2+ ions modulate gating, and in some cases, the binding of protons and Ca2+ is interdependent. Here, we functionally characterize a DEG/ENaC channel from the early-diverging animal Trichoplax adhaerens, TadNaC6, that conducts Na+-selective leak currents in vitro sensitive to blockade by both extracellular protons and Ca2+. We determine that proton block is enhanced in low external Ca2+ concentration, whereas calcium block is enhanced in low external proton concentration, indicative of competitive binding of these two ligands to extracellular sites of the channel protein. TadNaC6 lacks most determinant residues for proton and Ca2+ sensitivity in other DEG/ENaC channels, and a mutation of one conserved residue (S353A) associated with Ca2+ block in rodent BASIC channels instead affected proton sensitivity, all indicative of independent evolution of H+ and Ca2+ sensitivity. Strikingly, TadNaC6 was potently activated by the general DEG/ENaC channel blocker amiloride, a rare feature only reported for the acid-activated channel ASIC3. The sequence and structural divergence of TadNaC6, coupled with its noncanonical functional features, provide unique opportunities for probing the proton, Ca2+, and amiloride regulation of DEG/ENaC channels and insight into the possible core-gating features of ancestral ion channels.
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Transcriptome profiling of Trichoplax adhaerens highlights its digestive epithelium and a rich set of genes for fast electrogenic and slow neuromodulatory cellular signaling
2019Co-Authors: Yuen Yan Wong, Wassim Elkhatib, Thomas Piekut, Adriano SenatoreAbstract:Abstract Background Trichoplax adhaerens is a fascinating early-diverging animal that lacks a nervous system and synapses, and yet is capable of directed motile feeding behavior culminating in the external digestion of microorganisms by secreted hydrolytic enzymes. The mechanisms by which Trichoplax cells communicate with each other to coordinate their activity and behavior is unclear, though recent studies have suggested that secreted regulatory peptides might be involved.Results Here, we generated a high quality mRNA transcriptome of Trichoplax adhaerens , and predicted secreted proteins to identify gene homologues for digestion, development, immunity, cell adhesion, and peptide signaling. Detailed annotation of the expressed Trichoplax gene set also identified a nearly complete set of electrogenic genes involved in fast neural signalling, plus a set of 665 G-protein coupled receptors that in the nervous system integrate with fast signalling machinery to modulate cellular excitability. Furthermore, Trichoplax expresses an array of genes involved in intracellular signaling, including the key effector enzymes protein kinases A and C that functionally link fast and slow cellular signaling. Also identified were nearly complete sets of pre- and post-synaptic scaffolding genes, most encoding appropriate protein domain architectures. Notably, the Trichoplax proteome was found to bear slightly reduced counts of synaptic protein interaction domains such as PDZ, SH3 and C2 compared to other animals, but abundance of these domains did not appear to predict the presence of synapses in early-diverging groups.Conclusions Despite its apparent cellular and morphological simplicity, Trichoplax expresses a rich set of genes involved in complex animal traits. The transcriptome presented here adds a valuable additional resource for molecular studies on Trichoplax genes, exemplified by our ability to clone cDNAs for nine full-length acid sensing ion channel proteins with almost perfect matches with their corresponding transcriptome sequences.
Bernd Schierwater - One of the best experts on this subject based on the ideXlab platform.
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Trichoplax genomes reveal profound admixture and suggest stable wild populations without bisexual reproduction.
Scientific reports, 2018Co-Authors: Kai Kamm, Peter F. Stadler, Hans-jürgen Osigus, Rob Desalle, Bernd SchierwaterAbstract:The phylum Placozoa officially consists of only a single described species, Trichoplax adhaerens, although several lineages can be separated by molecular markers, geographical distributions and environmental demands. The placozoan 16S haplotype H2 (Trichoplax sp. H2) is the most robust and cosmopolitan lineage of placozoans found to date. In this study, its genome was found to be distinct but highly related to the Trichoplax adhaerens reference genome, for remarkably unique reasons. The pattern of variation and allele distribution between the two lineages suggests that both originate from a single interbreeding event in the wild, dating back at least several decades ago, and both seem not to have engaged in sexual reproduction since. We conclude that populations of certain placozoan haplotypes remain stable for long periods without bisexual reproduction. Furthermore, allelic variation within and between the two Trichoplax lineages indicates that successful bisexual reproduction between related placozoan lineages might serve to either counter accumulated negative somatic mutations or to cope with changing environmental conditions. On the other hand, enrichment of neutral or beneficial somatic mutations by vegetative reproduction, combined with rare sexual reproduction, could instantaneously boost genetic variation, generating novel ecotypes and eventually species.
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High cell diversity and complex peptidergic signalling underlie placozoan behaviour
2018Co-Authors: Frederique Varoqueaux, Kai Kamm, Bernd Schierwater, Elizabeth A Williams, Susie Grandemange, Luca Truscello, Gáspár Jékely, Dirk FasshauerAbstract:Placozoans, together with sponges, are the only animals devoid of a nervous system and muscles, yet both respond to sensory stimulation in a coordinated manner. How behavioural control in these free-living animals is achieved in the absence of neurons and, more fundamentally, how the first neurons evolved from more primitive communication cells during the rise of animals is not yet understood. The placozoan Trichoplax adhaerens is a millimeter-wide, flat, free-living marine animal composed of six morphologically identified cell types distributed across a simple bodyplan: a flat upper epithelium and a cylindrical lower epithelium interspersed with a loose layer of fiber cells. Its genome encodes several proneuropeptide genes and genes involved in neurosecretion in animals with a nervous system. Here we investigate neuropeptide signalling in Trichoplax adhaerens. We found specific expression of several neuropeptides in non-overlapping cell populations distributed over the three cell layers, revealing an unsuspected cell-type diversity of Trichoplax adhaerens. Using live imaging, we uncovered that treatments with 11 different neuropeptides elicited striking and consistent effects on the animals shape, patterns of movement and velocity that we categorized under three main types: (i) crinkling, (ii) turning, and (iii) flattening and churning. Together, the data demonstrate a crucial role for peptidergic signalling in nerveless placozoans and suggest that peptidergic volume signalling may have predated synaptic signalling in the evolution of nervous systems.
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Trichoplax adhaerens reveals a network of nuclear receptors sensitive to 9-cis-retinoic acid at the base of metazoan evolution
PeerJ, 2017Co-Authors: Jan Philipp Novotný, Bernd Schierwater, Ahmed Ali Chughtai, Markéta Kostrouchová, Veronika Kostrouchová, David Kostrouch, Filip Kaššák, Radek Kaňa, Zdenek KostrouchAbstract:Trichoplax adhaerens, the only known species of Placozoa is likely to be closely related to an early metazoan that preceded branching of Cnidaria and Bilateria. This animal species is surprisingly well adapted to free life in the World Ocean inhabiting tidal costal zones of oceans and seas with warm to moderate temperatures and shallow waters. The genome of T. adhaerens (sp. Grell) includes four nuclear receptors, namely orthologue of RXR (NR2B), HNF4 (NR2A), COUP-TF (NR2F) and ERR (NR3B) that show a high degree of similarity with human orthologues. In the case of RXR, the sequence identity to human RXR alpha reaches 81% in the DNA binding domain and 70% in the ligand binding domain. We show that T. adhaerens RXR (TaRXR) binds 9-cis retinoic acid (9-cis-RA) with high affinity, as well as high specificity and that exposure of T. adhaerens to 9-cis-RA regulates the expression of the putative T. adhaerens orthologue of vertebrate L-malate-NADP+ oxidoreductase (EC 1.1.1.40) which in vertebrates is regulated by a heterodimer of RXR and thyroid hormone receptor. Treatment by 9-cis-RA alters the relative expression profile of T. adhaerens nuclear receptors, suggesting the existence of natural ligands. Keeping with this, algal food composition has a profound effect on T. adhaerens growth and appearance. We show that nanomolar concentrations of 9-cis-RA interfere with T. adhaerens growth response to specific algal food and causes growth arrest. Our results uncover an endocrine-like network of nuclear receptors sensitive to 9-cis-RA in T. adhaerens and support the existence of a ligand-sensitive network of nuclear receptors at the base of metazoan evolution.
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Trichoplax adhaerens reveals an endocrine-like network sensitive to 9-cis-retinoic acid at the base of metazoan evolution
2017Co-Authors: Jan Philipp Novotný, Bernd Schierwater, Ahmed Ali Chughtai, Markéta Kostrouchová, Veronika Kostrouchová, David Kostrouch, Filip Kaššák, Radek Kaňa, Zdenek KostrouchAbstract:Trichoplax adhaerens, the only known species of Placozoa is likely to be closely related to an early metazoan that preceded branching of Cnidaria and Bilateria. This animal species is surprisingly well adapted to free life in the World Ocean inhabiting tidal costal zones of oceans and seas with warm to moderate temperatures and shallow waters. The genome of T. adhaerens (sp. Grell) includes four nuclear receptors, namely homologues of RXR (NR2B), HNF4 (NR2A), COUP (NR2F) and ERR (NR3B) that show a high degree of similarity with human homologues. In the case of RXR, the sequence identity to human RXR alpha reaches 81% in the DNA binding domain and 70 % in the ligand binding domain. We show that T. adhaerens RXR (TaRXR) binds 9-cis retinoic acid (9-cis-RA) with high affinity, as well as high specificity and that exposure of T. adhaerens to 9-cis-RA regulates the expression of the putative T. adhaerens homologue of vertebrate L-malate-NADP+ oxidoreductase (EC 1.1.1.40) which in vertebrates is regulated by a heterodimer of RXR and thyroid hormone receptor. Treatment by 9-cis-RA alters the relative expression profile of T. adhaerens nuclear receptors, suggesting the existence of natural ligands. Keeping with this, algal food composition has profound effect on T. adhaerens growth and appearance. Our results uncover an endocrine-like network of nuclear receptors sensitive to 9-cis-RA in T. adhaerens and support the existence of a ligand-sensitive network of nuclear receptors at the base of metazoan evolution.
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Placozoan cox1 “mRNA editing” scenario.
2017Co-Authors: Hans-jürgen Osigus, Michael Eitel, Bernd SchierwaterAbstract:The shown scenario is based on Trichoplax adhaerens EST data (Burger et al., 2009). The figure only shows cox1 exons 6 and 7 and the intron between them (following NC_008151). After splicing of exons the “U” at the 3’ end of exon 6 is converted to a “C” by mRNA editing. Exons and introns are illustrated in yellow and blue, respectively. mRNA editing (“U-to-C”) is illustrated by red lightning. For further explanations see text and Burger et al., 2009.
Andreas Heyland - One of the best experts on this subject based on the ideXlab platform.
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Microscopy Studies of Placozoans.
Methods in molecular biology (Clifton N.J.), 2020Co-Authors: Carolyn L Smith, Thomas S. Reese, Tatiana D. Mayorova, Christine A. Winters, Sally P. Leys, Andreas HeylandAbstract:Trichoplax adhaerens is an enigmatic animal with an extraordinarily simple morphology and a cellular organization, which are the focus of current research. Protocols outlined here provide detailed descriptions of advanced techniques for light and electron microscopic studies of Trichoplax. Studies using these techniques have enhanced our understanding of cell type diversity and function in placozoans and have provided insight into the evolution, development, and physiology of this little understood group.
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Functional Studies of Trichoplax adhaerens Voltage-Gated Calcium Channel Activity.
Methods in molecular biology (Clifton N.J.), 2020Co-Authors: Julia Gauberg, Adriano Senatore, Andreas HeylandAbstract:Trichoplax adhaerens is a member of the phylum Placozoa, an enigmatic group of benthic animals with remarkably simple morphology. While initial work on these organisms has primarily focused on their morphology and the development of genomic resources, Trichoplax has received increased attention as a model for studying the evolution of nervous and sensory systems. This work is motivated by the fact that Trichoplax features distinct behaviours and responses to environmental stimuli. Therefore, much progress has been made in recent years on the molecular, cellular, and behavioral understanding of this organism. Methods outlined here provide hands-on approaches to cutting edge molecular and cellular techniques to record cellular activities in Trichoplax.
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Trichoplax adhaerens , an Enigmatic Basal Metazoan with Potential
Methods in molecular biology (Clifton N.J.), 2014Co-Authors: Andreas Heyland, Roger P. Croll, Sophie Goodall, Jeff Kranyak, Russell C. WyethAbstract:Trichoplax adhaerens is an enigmatic basal animal with an extraordinarily simple morphological organization and surprisingly complex behaviors. Basic morphological, molecular and behavioral work is essential to better understand the unique and curious life style of these organisms. We provide basic instructions on how Trichoplax can be cultured and studied in the laboratory emphasizing behavioral and cellular aspects.
Timothy Q. Dubuc - One of the best experts on this subject based on the ideXlab platform.
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dorsal ventral genes are part of an ancient axial patterning system evidence from Trichoplax adhaerens placozoa
Molecular Biology and Evolution, 2019Co-Authors: Joseph F. Ryan, Timothy Q. Dubuc, Mark Q. MartindaleAbstract:Placozoa are a morphologically simplistic group of marine animals found globally in tropical and subtropical environments. They consist of two named species, Trichoplax adhaerens and more recently Hoilungia hongkongensis, both with roughly six morphologically distinct cell types. With a sequenced genome, a limited number of cell types, and a simple flattened morphology, Trichoplax is an ideal model organism from which to explore the biology of an animal with a cellular complexity analagous to that of the earliest animals. Using a new approach for identification of gene expression patterns, this research looks at the relationship of Chordin/TgfΒ signaling and the axial patterning system of Placozoa. Our results suggest that placozoans have an oral-aboral axis similar to cnidarians and that the parahoxozoan ancestor (common ancestor of Placozoa and Cnidaria) was likely radially symmetric.
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“Dorsal–Ventral” Genes Are Part of an Ancient Axial Patterning System: Evidence from Trichoplax adhaerens (Placozoa)
Molecular biology and evolution, 2019Co-Authors: Timothy Q. Dubuc, Joseph F. Ryan, Mark Q. MartindaleAbstract:Placozoa are a morphologically simplistic group of marine animals found globally in tropical and subtropical environments. They consist of two named species, Trichoplax adhaerens and more recently Hoilungia hongkongensis, both with roughly six morphologically distinct cell types. With a sequenced genome, a limited number of cell types, and a simple flattened morphology, Trichoplax is an ideal model organism from which to explore the biology of an animal with a cellular complexity analagous to that of the earliest animals. Using a new approach for identification of gene expression patterns, this research looks at the relationship of Chordin/TgfΒ signaling and the axial patterning system of Placozoa. Our results suggest that placozoans have an oral-aboral axis similar to cnidarians and that the parahoxozoan ancestor (common ancestor of Placozoa and Cnidaria) was likely radially symmetric.
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The radial expression of dorsal-ventral patterning genes in placozoans, Trichoplax adhaerens, argues for an oral-aboral axis
2018Co-Authors: Timothy Q. Dubuc, Joseph F. Ryan, Yuriy V. Bobkov, Mark Q. MartindaleAbstract:The placozoans are a morphologically simplistic group of marine animals found globally in tropical and subtropical environments. They consist of a single named species, Trichoplax adhaerens and have roughly six morphologically distinct cell types. With a sequenced genome, a limited number of cell-types and a simple flattened morphology, Trichoplax is an ideal model organism to understand cellular dynamics and tissue patterning in the first animals. Using new approaches for identification of gene expression patterns this research looks at the relationship of Chordin/Tgfβ signaling and the axial patterning system of Placozoa. Our results suggest that placozoans have an oral-aboral axis similar to cnidarians and that the parahoxozoan ancestor (common ancestor of Placozoa and Cnidaria) was likely radially symmetric.
