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NCBI: db=pubmed; Term=(((((((((echinoderm) AND developmental biology) OR strongylocentrotus purpuratus) OR patiria miniata) OR lytechinus variegatus) OR eucidaris tribuloides) OR parastichopus parvimensis) OR ophiothrix apiculata) OR allocentrotus fragilis) OR strongylocentrotus franciscanus AND ( ( Humans[Mesh] OR Animals[Mesh:noexp] ) ) AND ("last 5 years"[PDat])
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Colorimetric method for determining viability of sea urchin sperm applied in toxicity tests.

Thu, 10/04/2018 - 08:09
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Colorimetric method for determining viability of sea urchin sperm applied in toxicity tests.

Ecotoxicology. 2018 Jul;27(5):499-504

Authors: Resgalla C, Máximo MV, Brasil MDN, Pessatti ML

Abstract
The aim of this study was to improve the methodological procedure for the evaluation of sea urchin (Lytechinus variegatus) sperm sensitivity in MTT (3-(4,5-dimethylthiazol-2yl)-2,5 diphenyltetrazolium bromide) enzyme reduction assays with the formation of formazan (purple color) in the interior of viable cells. Assays were carried out with the reference toxicants sodium dodecyl sulfate (SDS), copper, zinc, cadmium and ammonium, using a sperm solution previously activated in sea water and a sperm solution prepared in sea water containing 400 μg L-1 verapamil, which enabled activation of the sperm to occur only when exposed to the toxicants. The assays performed with sperm in verapamil presented similar sensitivity to that shown in the fertilization tests with copper, zinc and SDS, while the assays carried out with the pre-activated sperm solution presented greater resistance to the action of the toxicants. It appears that the action of verapamil involves an intracellular effect on the distribution of Ca2+ ions and that the toxicants used prevent the metabolic reactivation of the sperm.

PMID: 29691785 [PubMed - indexed for MEDLINE]

Categories: pubmed

Effects of Nodal inhibition on development of temnopleurid sea urchins.

Wed, 10/03/2018 - 08:07
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Effects of Nodal inhibition on development of temnopleurid sea urchins.

Evol Dev. 2018 05;20(3-4):91-99

Authors: Kasahara M, Kobayashi C, Sakaguchi C, Miyahara C, Yamanaka A, Kitazawa C

Abstract
Adult rudiment formation in some temnopleurids begins with the formation of a cell mass that is pinched off the left ectoderm in early larval development. The cell mass forms the adult rudiment with the left coelomic pouch of the mesodermal region. However, details of the mechanisms to establish position of the cell mass are still unknown. We analyzed the inhibiting effect of Nodal, a factor for morphogenesis of the oral region and right side, for location of the cell mass, in four temnopleurids. Pulse inhibition, at least 5 min inhibition, during coelomic pouch formation allowed a cell mass to form on both sides, whereas treatments after that period did not. These results indicate that Nodal signaling controls the oral-aboral axis before gastrulation and then affects the position of the cell mass and adult rudiment up to coelomic pouch formation. They also indicate that the position of the adult rudiment under Nodal signaling pathways is conserved in temnopleurids, as adult rudiment formation is dependent on the cell mass.

PMID: 29806731 [PubMed - indexed for MEDLINE]

Categories: pubmed

Glycosylation Fosters Interactions between Model Sea Urchin Spicule Matrix Proteins. Implications for Embryonic Spiculogenesis and Biomineralization.

Wed, 10/03/2018 - 08:07
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Glycosylation Fosters Interactions between Model Sea Urchin Spicule Matrix Proteins. Implications for Embryonic Spiculogenesis and Biomineralization.

Biochemistry. 2018 05 29;57(21):3032-3035

Authors: Jain G, Pendola M, Koutsoumpeli E, Johnson S, Evans JS

Abstract
The formation of embryonic mineralized skeletal elements (spicules) in the sea urchin requires the participation of proteins, many of which may interact with one another and assist in the creation of an extracellular matrix wherein mineral formation takes place. To probe this, we created a sea urchin spicule recombinant model protein pair system wherein we tested the interactions between two major spicule proteins, SpSM50 and the glycoprotein, SpSM30B/C. Both proteins are strong hydrogelators that manipulate early and later events in mineral formation. We discovered that the anionic glycan moieties of SpSM30B/C are required for interaction with the SpSM50 protein and that these interactions are Ca(II)-independent. In addition, when these proteins form a complex, they create hybrid hydrogel particles that are physically distinct from their individual counterparts. Thus, glycan-mediated interactions play an important role in in vitro spicule protein assembly and most likely within the spicule itself.

PMID: 29757633 [PubMed - indexed for MEDLINE]

Categories: pubmed

Global analysis of primary mesenchyme cell cis-regulatory modules by chromatin accessibility profiling.

Thu, 09/27/2018 - 07:52
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Global analysis of primary mesenchyme cell cis-regulatory modules by chromatin accessibility profiling.

BMC Genomics. 2018 03 20;19(1):206

Authors: Shashikant T, Khor JM, Ettensohn CA

Abstract
BACKGROUND: The developmental gene regulatory network (GRN) that underlies skeletogenesis in sea urchins and other echinoderms is a paradigm of GRN structure, function, and evolution. This transcriptional network is deployed selectively in skeleton-forming primary mesenchyme cells (PMCs) of the early embryo. To advance our understanding of this model developmental GRN, we used genome-wide chromatin accessibility profiling to identify and characterize PMC cis-regulatory modules (CRMs).
RESULTS: ATAC-seq (Assay for Transposase-Accessible Chromatin using sequencing) analysis of purified PMCs provided a global picture of chromatin accessibility in these cells. We used both ATAC-seq and DNase-seq (DNase I hypersensitive site sequencing) to identify > 3000 sites that exhibited increased accessibility in PMCs relative to other embryonic cell lineages, and provide both computational and experimental evidence that a large fraction of these sites represent bona fide skeletogenic CRMs. Putative PMC CRMs were preferentially located near genes differentially expressed by PMCs and consensus binding sites for two key transcription factors in the PMC GRN, Alx1 and Ets1, were enriched in these CRMs. Moreover, a high proportion of candidate CRMs drove reporter gene expression specifically in PMCs in transgenic embryos. Surprisingly, we found that PMC CRMs were partially open in other embryonic lineages and exhibited hyperaccessibility as early as the 128-cell stage.
CONCLUSIONS: Our work provides a comprehensive picture of chromatin accessibility in an early embryonic cell lineage. By identifying thousands of candidate PMC CRMs, we significantly enhance the utility of the sea urchin skeletogenic network as a general model of GRN architecture and evolution. Our work also shows that differential chromatin accessibility, which has been used for the high-throughput identification of enhancers in differentiated cell types, is a powerful approach for the identification of CRMs in early embryonic cells. Lastly, we conclude that in the sea urchin embryo, CRMs that control the cell type-specific expression of effector genes are hyperaccessible several hours in advance of gene activation.

PMID: 29558892 [PubMed - indexed for MEDLINE]

Categories: pubmed

The role of dissolved organic carbon concentration and composition on nickel toxicity to early life-stages of the blue mussel Mytilus edulis and purple sea urchin Strongylocentrotus purpuratus.

Tue, 09/25/2018 - 07:47
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The role of dissolved organic carbon concentration and composition on nickel toxicity to early life-stages of the blue mussel Mytilus edulis and purple sea urchin Strongylocentrotus purpuratus.

Ecotoxicol Environ Saf. 2018 Sep 30;160:162-170

Authors: Blewett TA, Dow EM, Wood CM, McGeer JC, Smith DS

Abstract
Nickel (Ni) emissions resulting from production and transportation raise concerns about the impact of Ni exposure to marine ecosystems. Ni bioavailability models are established for FW systems, but the influence of chemical parameters (e.g. dissolved organic carbon (DOC)) on Ni toxicity within marine systems is less well understood. To examine the effects of DOC concentration and composition on Ni toxicity, acute toxicity tests were conducted on early life-stages of blue mussels (Mytilus edulis) and sea urchin embryos (Strongylocentrotus purpuratus) in full strength sea water (32 ppt). Nine different field collected samples of water with varying concentration (up to 4.5 mg C/L) and composition of DOC were collected from the east coast of the United States. Organic matter compositional analysis included molecular fluorescence and absorbance spectroscopy. The different DOC sources had different protective effects against embryo toxicity. The control (no DOC) Ni 48 h-EC50 for Mytilus embryos was 133 µg/L (95% confidence interval (C.I.) of 123-144 µg/L), while Strongylocentrotus embryos displayed control 96-h EC50 values of 207 µg/L (167-247 µg/L). The most significantly protective sample had high humic acid concentrations (as determined from fluorescence spectroscopy), which yielded an EC50 of 195 µg/L (169-222 µg/L) for Mytilus, and an EC50 of 394 µg/L (369-419 µg/L) for S. purpuratus. Among all samples, protection was related to both DOC quantity and quality, with fluorescence-resolved humic and fulvic acid concentrations showing the strongest correlations with protection for both species. These data suggest that DOC is protective against Ni toxicity in M. edulis and S. purpuratus, and that accounting for a DOC quality factor will improve predictive toxicity models such as the biotic ligand model.

PMID: 29804012 [PubMed - indexed for MEDLINE]

Categories: pubmed

Engineering Pichia pastoris for Efficient Production of a Novel Bifunctional Strongylocentrotus purpuratus Invertebrate-Type Lysozyme.

Tue, 09/25/2018 - 07:47
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Engineering Pichia pastoris for Efficient Production of a Novel Bifunctional Strongylocentrotus purpuratus Invertebrate-Type Lysozyme.

Appl Biochem Biotechnol. 2018 Oct;186(2):459-475

Authors: Huang P, Shi J, Sun Q, Dong X, Zhang N

Abstract
Lysozymes are known as ubiquitously distributed immune effectors with hydrolytic activity against peptidoglycan, the major bacterial cell wall polymer, to trigger cell lysis. In the present study, the full-length cDNA sequence of a novel sea urchin Strongylocentrotus purpuratus invertebrate-type lysozyme (sp-iLys) was synthesized according to the codon usage bias of Pichia pastoris and was cloned into a constitutive expression plasmid pPIC9K. The resulting plasmid, pPIC9K-sp-iLys, was integrated into the genome of P. pastoris strain GS115. The bioactive recombinant sp-iLys was successfully secreted into the culture broth by positive transformants. The highest lytic activity of 960 U/mL of culture supernatant was reached in fed-batch fermentation. Using chitin affinity chromatography and gel-filtration chromatography, recombinant sp-iLys was produced with a yield of 94.5 mg/L and purity of > 99%. Recombinant sp-iLys reached its peak lytic activity of 8560 U/mg at pH 6.0 and 30 °C and showed antimicrobial activities against Gram-negative bacteria (Vibrio vulnificus, Vibrio parahemolyticus, and Aeromonas hydrophila) and Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis). In addition, recombinant sp-iLys displayed isopeptidase activity which reached the peak at pH 7.5 and 37 °C with the presence of 0.05 M Na+. In conclusion, this report describes the heterologous expression of recombinant sp-iLys in P. pastoris on a preparative-scale, which possesses lytic activity and isopeptidase activity. This suggests that sp-iLys might play an important role in the innate immunity of S. purpuratus.

PMID: 29651700 [PubMed - indexed for MEDLINE]

Categories: pubmed

Parental exposure to heavy fuel oil induces developmental toxicity in offspring of the sea urchin Strongylocentrotus intermedius.

Fri, 09/21/2018 - 07:39
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Parental exposure to heavy fuel oil induces developmental toxicity in offspring of the sea urchin Strongylocentrotus intermedius.

Ecotoxicol Environ Saf. 2018 Sep 15;159:109-119

Authors: Duan M, Xiong D, Yang M, Xiong Y, Ding G

Abstract
The present study investigated the toxic effects of parental (maternal/paternal) exposure to heavy fuel oil (HFO) on the adult reproductive state, gamete quality and development of the offspring of the sea urchin Strongylocentrotus intermedius. Adult sea urchins were exposed to effluents from HFO-oiled gravel columns for 7 days to simulate an oil-contaminated gravel shore, and then gametes of adult sea urchins were used to produce embryos to determine developmental toxicity. For adult sea urchins, no significant difference in the somatic size and weight was found between the various oil loadings tested, while the gonad weight and gonad index were significantly decreased at higher oil loadings. The spawning ability of adults and fecundity of females significantly decreased. For gametes, no effect was observed on the egg size and fertilization success in any of the groups. However, a significant increase in the percentage of anomalies in the offspring was observed and then quantified by an integrative toxicity index (ITI) at 24 and 48 h post fertilization. The offspring from exposed parents showed higher ITI values with more malformed embryos. The results confirmed that parental exposure to HFO can cause adverse effects on the offspring and consequently affect the recruitment and population maintenance of sea urchins.

PMID: 29730404 [PubMed - indexed for MEDLINE]

Categories: pubmed

Evolutionary recruitment of flexible Esrp-dependent splicing programs into diverse embryonic morphogenetic processes.

Thu, 09/20/2018 - 07:37
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Evolutionary recruitment of flexible Esrp-dependent splicing programs into diverse embryonic morphogenetic processes.

Nat Commun. 2017 11 27;8(1):1799

Authors: Burguera D, Marquez Y, Racioppi C, Permanyer J, Torres-Méndez A, Esposito R, Albuixech-Crespo B, Fanlo L, D'Agostino Y, Gohr A, Navas-Perez E, Riesgo A, Cuomo C, Benvenuto G, Christiaen LA, Martí E, D'Aniello S, Spagnuolo A, Ristoratore F, Arnone MI, Garcia-Fernàndez J, Irimia M

Abstract
Epithelial-mesenchymal interactions are crucial for the development of numerous animal structures. Thus, unraveling how molecular tools are recruited in different lineages to control interplays between these tissues is key to understanding morphogenetic evolution. Here, we study Esrp genes, which regulate extensive splicing programs and are essential for mammalian organogenesis. We find that Esrp homologs have been independently recruited for the development of multiple structures across deuterostomes. Although Esrp is involved in a wide variety of ontogenetic processes, our results suggest ancient roles in non-neural ectoderm and regulating specific mesenchymal-to-epithelial transitions in deuterostome ancestors. However, consistent with the extensive rewiring of Esrp-dependent splicing programs between phyla, most developmental defects observed in vertebrate mutants are related to other types of morphogenetic processes. This is likely connected to the origin of an event in Fgfr, which was recruited as an Esrp target in stem chordates and subsequently co-opted into the development of many novel traits in vertebrates.

PMID: 29180615 [PubMed - indexed for MEDLINE]

Categories: pubmed

HpBase: A genome database of a sea urchin, Hemicentrotus pulcherrimus.

Tue, 09/18/2018 - 07:33
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HpBase: A genome database of a sea urchin, Hemicentrotus pulcherrimus.

Dev Growth Differ. 2018 Apr;60(3):174-182

Authors: Kinjo S, Kiyomoto M, Yamamoto T, Ikeo K, Yaguchi S

Abstract
To understand the mystery of life, it is important to accumulate genomic information for various organisms because the whole genome encodes the commands for all the genes. Since the genome of Strongylocentrotus purpratus was sequenced in 2006 as the first sequenced genome in echinoderms, the genomic resources of other North American sea urchins have gradually been accumulated, but no sea urchin genomes are available in other areas, where many scientists have used the local species and reported important results. In this manuscript, we report a draft genome of the sea urchin Hemincentrotus pulcherrimus because this species has a long history as the target of developmental and cell biology in East Asia. The genome of H. pulcherrimus was assembled into 16,251 scaffold sequences with an N50 length of 143 kbp, and approximately 25,000 genes were identified in the genome. The size of the genome and the sequencing coverage were estimated to be approximately 800 Mbp and 100×, respectively. To provide these data and information of annotation, we constructed a database, HpBase (http://cell-innovation.nig.ac.jp/Hpul/). In HpBase, gene searches, genome browsing, and blast searches are available. In addition, HpBase includes the "recipes" for experiments from each lab using H. pulcherrimus. These recipes will continue to be updated according to the circumstances of individual scientists and can be powerful tools for experimental biologists and for the community. HpBase is a suitable dataset for evolutionary, developmental, and cell biologists to compare H. pulcherrimus genomic information with that of other species and to isolate gene information.

PMID: 29532461 [PubMed - indexed for MEDLINE]

Categories: pubmed

A disassembly-driven mechanism explains F-actin-mediated chromosome transport in starfish oocytes.

Fri, 08/31/2018 - 07:18
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A disassembly-driven mechanism explains F-actin-mediated chromosome transport in starfish oocytes.

Elife. 2018 01 19;7:

Authors: Bun P, Dmitrieff S, Belmonte JM, Nédélec FJ, Lénárt P

Abstract
While contraction of sarcomeric actomyosin assemblies is well understood, this is not the case for disordered networks of actin filaments (F-actin) driving diverse essential processes in animal cells. For example, at the onset of meiosis in starfish oocytes a contractile F-actin network forms in the nuclear region transporting embedded chromosomes to the assembling microtubule spindle. Here, we addressed the mechanism driving contraction of this 3D disordered F-actin network by comparing quantitative observations to computational models. We analyzed 3D chromosome trajectories and imaged filament dynamics to monitor network behavior under various physical and chemical perturbations. We found no evidence of myosin activity driving network contractility. Instead, our observations are well explained by models based on a disassembly-driven contractile mechanism. We reconstitute this disassembly-based contractile system in silico revealing a simple architecture that robustly drives chromosome transport to prevent aneuploidy in the large oocyte, a prerequisite for normal embryonic development.

PMID: 29350616 [PubMed - indexed for MEDLINE]

Categories: pubmed

Relation of Nodal expression to the specification of the dorsal-ventral axis and tissue patterning in the starfish Patiria pectinifera.

Tue, 08/28/2018 - 07:16
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Relation of Nodal expression to the specification of the dorsal-ventral axis and tissue patterning in the starfish Patiria pectinifera.

Dev Growth Differ. 2017 Dec;59(9):724-740

Authors: Sasaki H, Kominami T

Abstract
In this study, we attempted to reveal fundamental aspects of starfish embryogenesis, particularly embryonic axis specification or determination, in Patiria pectinifera. We first cloned PpNodal, which is known to play an important role in the specification of the embryonic axis in a wide range of animals, and studied its expression profile. PpNodal expression was first detected at the mid-blastula stage and showed a single peak around the onset of gastrulation. These features of Nodal expression were shifted to later stages by several hours, compared with those of sea urchin embryos. After the gastrulation started, the expression level became gradually lowered up to the early bipinnaria stage, while the expression level became drastically lowered in sea urchin embryos during gastrulation. The localized Nodal expression in the presumptive oral region was not observed in starfish embryos, unlike in sea urchin embryos. Furthermore, SB431542, an inhibitor of Nodal receptor, did not affect the formation of the DV axis, although it caused the loss of left-right asymmetry. In contrast to this, SB525334, a specific inhibitor of TGF-beta receptor, caused the complete loss of the DV axis. Thus, the usage of signaling molecules during early embryogenesis likely varies among echinoderm classes.

PMID: 29098682 [PubMed - indexed for MEDLINE]

Categories: pubmed