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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])
Updated: 11 hours 15 min ago

Transcriptional profiles of early stage red sea urchins (Mesocentrotus franciscanus) reveal differential regulation of gene expression across development.

Fri, 01/24/2020 - 18:38
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Transcriptional profiles of early stage red sea urchins (Mesocentrotus franciscanus) reveal differential regulation of gene expression across development.

Mar Genomics. 2019 Dec;48:100692

Authors: Wong JM, Gaitán-Espitia JD, Hofmann GE

Abstract
The red sea urchin, Mesocentrotus franciscanus, is an ecologically important kelp forest species that also serves as a valuable fisheries resource. In this study, we have assembled and annotated a developmental transcriptome for M. franciscanus that represents eggs and six stages of early development (8- to 16-cell, morula, hatched blastula, early gastrula, prism and early pluteus). Characterization of the transcriptome revealed distinct patterns of gene expression that corresponded to major developmental and morphological processes. In addition, the period during which maternally-controlled transcription was terminated and the zygotic genome was activated, the maternal-to-zygotic transition (MZT), was found to begin during early cleavage and persist through the hatched blastula stage, an observation that is similar to the timing of the MZT in other sea urchin species. The presented developmental transcriptome will serve as a useful resource for investigating, in both an ecological and fisheries context, how the early developmental stages of this species respond to environmental stressors.

PMID: 31227413 [PubMed - indexed for MEDLINE]

Categories: pubmed

Establishment of knockout adult sea urchins by using a CRISPR-Cas9 system.

Wed, 01/15/2020 - 18:24
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Establishment of knockout adult sea urchins by using a CRISPR-Cas9 system.

Dev Growth Differ. 2019 Aug;61(6):378-388

Authors: Liu D, Awazu A, Sakuma T, Yamamoto T, Sakamoto N

Abstract
Sea urchins are used as a model organism for research on developmental biology and gene regulatory networks during early development. Gene knockdown by microinjection of morpholino antisense oligonucleotide (MASO) has been used to analyze gene function in early sea urchin embryos. However, as the effect of MASO is not long lasting, it is impossible to perturb genes expressed during late development by MASO. Recent advances in genome editing technologies have enabled gene modification in various organisms. We previously reported genome editing in the sea urchin Hemicentrotus pulcherrimus using zinc-finger nuclease (ZFN) and transcription activator-like effector nuclease (TALEN); however, the efficiencies of these technologies were not satisfactory. Here, we applied clustered regularly interspaced short palindromic repeat (CRISPR)-CRISPR-associated nuclease 9 (Cas9) technology to knock out the Pks1 gene in H. pulcherrimus. When sgRNAs targeting Pks1, which is required for the biosynthesis of larval pigment, were microinjected into fertilized eggs with SpCas9 mRNA, high-efficiency mutagenesis was achieved within 24 hr post fertilization and SpCas9/sgRNA-injected pluteus larvae had an albino phenotype. One of the sgRNAs yielded 100% mutagenesis efficiency, and no off-target effect was detected. In addition, the albino phenotype was maintained in juvenile sea urchins after metamorphosis, and the knockout sea urchins survived for at least one year and grew to albino adult sea urchins. These findings suggest that knockout adult sea urchins were successfully established and the CRISPR-Cas9 system is a feasible method for analyzing gene functions from late developmental to adult stage.

PMID: 31359433 [PubMed - indexed for MEDLINE]

Categories: pubmed

Harnessing Natural Product Diversity for Fluorophore Discovery: Naturally Occurring Fluorescent Hydroxyanthraquinones from the Marine Crinoid Pterometra venusta.

Fri, 01/03/2020 - 17:37
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Harnessing Natural Product Diversity for Fluorophore Discovery: Naturally Occurring Fluorescent Hydroxyanthraquinones from the Marine Crinoid Pterometra venusta.

J Nat Prod. 2018 12 28;81(12):2750-2755

Authors: Singh AJ, Gorka AP, Bokesch HR, Wamiru A, O'Keefe BR, Schnermann MJ, Gustafson KR

Abstract
Fluorescent small molecules are important tools in many aspects of modern biology. A two-stage evaluation process involving fluorescence screening and live-cell imaging was developed to facilitate the identification of new fluorescent probes from extracts housed within the NCI Natural Products Repository. To this end, over 2000 extracts and prefractionated samples were examined, including an extract from the marine crinoid Pterometra venusta. An optically guided evaluation involving stepwise fluorescence screening and live-cell imaging was developed to enable the isolation of fluorescent natural products. These efforts resulted in the isolation of six hydroxyanthraquinone compounds, three of which are new natural products. These purified metabolites were examined for their potential as cellular imaging probes, and they demonstrate that natural product libraries can be a good source of new fluorescent agents.

PMID: 30495954 [PubMed - indexed for MEDLINE]

Categories: pubmed

Immune activity at the gut epithelium in the larval sea urchin.

Tue, 12/31/2019 - 17:35
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Immune activity at the gut epithelium in the larval sea urchin.

Cell Tissue Res. 2019 Sep;377(3):469-474

Authors: Buckley KM, Rast JP

Abstract
The embryo of the purple sea urchin has been a fruitful model for the study of developmental gene regulatory networks. For similar reasons, the feeding sea urchin larva provides a gene regulatory model to investigate immune interactions at the gut epithelium. Here we describe what is known of the gut structure and immune cells of the sea urchin larva, and the cellular and gene expression response of the larva to gut-associated immune challenge. As a focused example of how the sea urchin larva can be compared with vertebrate systems, we discuss the expression and function of the IL-17 signalling system in the course of the larval immune response.

PMID: 31463705 [PubMed - indexed for MEDLINE]

Categories: pubmed

Development and evolution of gut structures: from molecules to function.

Tue, 12/31/2019 - 17:35
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Development and evolution of gut structures: from molecules to function.

Cell Tissue Res. 2019 Sep;377(3):445-458

Authors: Annunziata R, Andrikou C, Perillo M, Cuomo C, Arnone MI

Abstract
The emergence of a specialized system for food digestion and nutrient absorption was a crucial innovation for multicellular organisms. Digestive systems with different levels of complexity evolved in different animals, with the endoderm-derived one-way gut of most bilaterians to be the prevailing and more specialized form. While the molecular events regulating the early phases of embryonic tissue specification have been deeply investigated in animals occupying different phylogenetic positions, the mechanisms underlying gut patterning and gut-associated structures differentiation are still mostly obscure. In this review, we describe the main discoveries in gut and gut-associated structures development in echinoderm larvae (mainly for sea urchin and, when available, for sea star) and compare them with existing information in vertebrates. An impressive degree of conservation emerges when comparing the transcription factor toolkits recruited for gut cells and tissue differentiation in animals as diverse as echinoderms and vertebrates, thus suggesting that their function emerged in the deuterostome ancestor.

PMID: 31446445 [PubMed - indexed for MEDLINE]

Categories: pubmed

The first mitochondrial genome of the model echinoid Lytechinus variegatus and insights into Odontophoran phylogenetics.

Tue, 12/31/2019 - 17:35
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The first mitochondrial genome of the model echinoid Lytechinus variegatus and insights into Odontophoran phylogenetics.

Genomics. 2019 07;111(4):710-718

Authors: Bronstein O, Kroh A

Abstract
Assembly of publically available next-generation sequence data facilitated the generation of three camarodont echinoid mitogenomes: two for the Green Urchin (Lytechinus variegatus) and one for the Red Urchin (Mesocentrotus franciscanus). The data generated are exploited in a phylogenomic analysis of the superfamily Odontophora, originally proposed for echinoids with tooth supports on the epiphyses of the jaw. The analysis highly supports this taxon and its current subdivision into three families: the Echinometridae, Toxopneustidae, and Strongylocentrotidae. The analysis furthermore implies that historical taxonomic issues between two members of the genus Strongylocentrotus (S. pallidus and S. droebachiensis) may have a genetic basis. The novel mitogenomes for the model species L. variegatus complements the draft genome available for this taxon, one of only three genome-enabled echinoid species. The assembly method applied herein, follows a divide-and-conquer approach that provides for reduced computational requirements and facilitates resolving assembly problems when processing ultra-high coverage next-generation sequence data.

PMID: 29660476 [PubMed - indexed for MEDLINE]

Categories: pubmed

Cryopreservation of embryos and larvae of the edible sea urchin loxechinus albus (Molina, 1782).

Thu, 12/19/2019 - 16:59
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Cryopreservation of embryos and larvae of the edible sea urchin loxechinus albus (Molina, 1782).

Cryobiology. 2019 02;86:84-88

Authors: Dupré E, Carvajal J

Abstract
The natural population of the edible red sea urchin, Loxechinus albus, is decreasing due to overfishing. The embryos and larvae of the species are highly useful for monitoring marine pollution, which makes it necessary to conserve gametes, embryos and larvae to facilitate their use in diverse areas of aquaculture and environmental quality monitoring. This need can be met by cryopreserving individuals representing the different developmental stages to provide an ongoing supply of genetic material of the species. The present study establishes a reproducible protocol for cryopreserving red sea urchin blastula and larvae. Toxicity tests were conducted in the first stage of this study using two permeable cryoprotectors, dimethyl sulfoxide (Me2SO) and propylene glycol (PG), at three concentrations (5%, 10% and 15%). The tests were repeated in the second stage, but mixing the cryoprotectors with 0.04 M of trehalose (TRE), a non-permeable cryoprotector. Cryopreservation tests were conducted in the third stage employing different freezing rates: 2 °C/min, 3 °C/min, 3.5 °C/min, 4 °C/min and 4.5 °C/min, using the cryoprotectors that yielded the highest post-incubation survival rates. The highest post-freezing survival rates for blastula (76 ± 7%) and larvae (79 ± 7%) were obtained with Me2SO at 10% + 0.04 M of trehalose, with freezing rates of 3 °C/min and 4.5 °C/min, respectively.

PMID: 30476465 [PubMed - indexed for MEDLINE]

Categories: pubmed

Identification and sequencing of the gene encoding DNA methyltransferase 3 (DNMT3) from sea cucumber, Apostichopus japonicus.

Wed, 12/18/2019 - 16:48
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Identification and sequencing of the gene encoding DNA methyltransferase 3 (DNMT3) from sea cucumber, Apostichopus japonicus.

Mol Biol Rep. 2019 Aug;46(4):3791-3800

Authors: Hong HH, Lee SG, Jo J, Oh J, Cheon S, Lee HG, Park C

Abstract
The sea cucumber Apostichopus japonicus is well known as a traditional tonic food and as a commercially important cultured aquatic species. This species produces saponins, and has a high potential to cope with environmental stress, such as aestivation, organ regeneration, and wound healing. Recently, several studies have shown that cellular reprogramming and the physiological responses of the sea cucumber to environmental changes, including aestivation, are potentially mediated by epigenetic DNA methylation. The DNA methyltransferase (DNMT)1 and DNMT3 genes are independent participants in the maintenance and de novo methylation of specific sequences. Sea urchin (Strongylocentrotus purpuratus) and starfish (Asterina pectinifera), which belong to the same phylum as A. japonicus, have both DNMT1 and DNMT3 genes. However, it was previously reported that DNMT1 is present, but DNMT3 is absent, in A. japonicus. In the present study, we sequenced the full-length cDNA of the A. japonicus DNMT3 gene. The newly sequenced DNMT3 gene comprises three major conserved domains (Pro-Trp-Trp-Pro (PWWP), plant homeodomain (PHD), and S-adenosylmethionine-dependent methyltransferase (AdoMet-MTase)), indicating that the DNMT3 possibly has de novo DNA methylation catalytic activity. Gene structure and phylogenetic analysis showed that sea cucumber DNMT3 is evolutionarily conserved in the Echinodermata. Next, we demonstrated the conservation of DNMT3 gene expression in sea cucumber and starfish belong to same phylum, echinoderm. Using reverse transcription-polymerase chain reaction, sea cucumber DNMT3 mRNA was detected in testis tissue, but not in other tissues tested, including the respiratory tree, muscle, tentacle, intestine, and ovary. This is inconsistent with previous reports, which showed the expression of DNMT3 in ovary, but not in testis of the starfish A. pectinifera, indicating the tissue- and species-specific expression of DNMT3 gene. Although further studies are needed to clarify the epigenetic regulatory mechanisms of DNMT3 and its application to the aquaculture industry, our findings may provide insights into the sea cucumber biology.

PMID: 31006102 [PubMed - indexed for MEDLINE]

Categories: pubmed

Wavy movements of epidermis monocilia drive the neurula rotation that determines left-right asymmetry in ascidian embryos.

Wed, 12/18/2019 - 16:48
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Wavy movements of epidermis monocilia drive the neurula rotation that determines left-right asymmetry in ascidian embryos.

Dev Biol. 2019 04 15;448(2):173-182

Authors: Yamada S, Tanaka Y, Imai KS, Saigou M, Onuma TA, Nishida H

Abstract
Tadpole larvae of the ascidian, Halocynthia roretzi, show morphological left-right asymmetry in the brain structures and the orientation of tail bending within the vitelline membrane. Neurula embryos rotate along the anterior-posterior axis in a counterclockwise direction, and then this rotation stops when the left side of the embryo is oriented downwards. Contact of the left-side epidermis with the vitelline membrane promotes nodal gene expression in the left-side epidermis. This is a novel mechanism in which rotation of whole embryos provides the initial cue for breaking left-right symmetry. Here we show that epidermal monocilia, which appear at the neurula rotation stage, generate the driving force for rotation. A ciliary protein, Arl13b, fused with Venus YFP was used for live imaging of ciliary movements. Although overexpression of wild-type Arl13b fusion protein resulted in aberrant movements of the cilia and abrogation of neurula rotation, mutant Arl13b fusion protein, in which the GTPase and coiled-coil domains were removed, did not affect the normal ciliary movements and neurula rotation. Epidermis cilia moved in a wavy and serpentine way like sperm flagella but not in a rotational way or beating way with effective stroke and recovery stroke. They moved very slowly, at 1/7 Hz, consistent with the low angular velocity of neurula rotation (ca. 43°/min). The tips of most cilia pointed in the opposite direction of embryonic rotation. Similar motility was also observed in Ciona robusta embryos. When embryos were treated with a dynein inhibitor, Ciliobrevin D, both ciliary movements and neurula rotation were abrogated, showing that ciliary movements drive neurula rotation in Halocynthia. The drug also inhibited Ciona neurula rotation. Our observations suggest that the driving force of rotation is generated using the vitelline membrane as a substrate but not by making a water current around the embryo. It is of evolutionary interest that ascidians use ciliary movements to break embryonic left-right symmetry, like in many vertebrates. Meanwhile, ascidian embryos rotate as a whole, similar to embryos of non-vertebrate deuterostomes, such as echinoderm, hemichordate, and amphioxus, while swimming.

PMID: 30059669 [PubMed - indexed for MEDLINE]

Categories: pubmed