Latest Publications

Subscribe to Latest Publications feed Latest Publications
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: 18 hours 51 min ago

The developmental transcriptomes of two sea biscuit species with differing larval types.

Tue, 12/18/2018 - 09:21
Related Articles

The developmental transcriptomes of two sea biscuit species with differing larval types.

BMC Genomics. 2018 May 18;19(1):368

Authors: Armstrong AF, Grosberg RK

Abstract
BACKGROUND: Larval developmental patterns are extremely varied both between and within phyla, however the genetic mechanisms leading to this diversification are poorly understood. We assembled and compared the developmental transcriptomes for two sea biscuit species (Echinodermata: Echinoidea) with differing patterns of larval development, to provide a resource for investigating the evolution of alternate life cycles. One species (Clypeaster subdepressus) develops via an obligately feeding larva which metamorphoses 3-4 weeks after fertilization; the other (Clypeaster rosaceus) develops via a rare, intermediate larval type-facultative feeding- and can develop through metamorphosis entirely based on egg provisioning in under one week.
RESULTS: Overall, the two transcriptomes are highly similar, containing largely orthologous contigs with similar functional annotation. However, we found distinct differences in gene expression patterns between the two species. Larvae from C. rosaceus, the facultative planktotroph, turned genes on at earlier stages and had less differentiation in gene expression between larval stages, whereas, C. subdepressus showed a higher degree of stage-specific gene expression.
CONCLUSION: This study is the first genetic analysis of a species with facultatively feeding larvae. Our results are consistent with known developmental differences between the larval types and raise the question of whether earlier onset of developmental genes is a key step in the evolution of a reduced larval period. By publishing a transcriptome for this rare, intermediate, larval type, this study adds developmental breadth to the current genetic resources, which will provide a valuable tool for future research on echinoderm development as well as studies on the evolution of development in general.

PMID: 29776340 [PubMed - indexed for MEDLINE]

Categories: pubmed

The solute carrier SLC9C1 is a Na+/H+-exchanger gated by an S4-type voltage-sensor and cyclic-nucleotide binding.

Sat, 12/15/2018 - 09:18
Related Articles

The solute carrier SLC9C1 is a Na+/H+-exchanger gated by an S4-type voltage-sensor and cyclic-nucleotide binding.

Nat Commun. 2018 07 18;9(1):2809

Authors: Windler F, Bönigk W, Körschen HG, Grahn E, Strünker T, Seifert R, Kaupp UB

Abstract
Voltage-sensing (VSD) and cyclic nucleotide-binding domains (CNBD) gate ion channels for rapid electrical signaling. By contrast, solute carriers (SLCs) that passively redistribute substrates are gated by their substrates themselves. Here, we study the orphan sperm-specific solute carriers SLC9C1 that feature a unique tripartite structure: an exchanger domain, a VSD, and a CNBD. Voltage-clamp fluorimetry shows that SLC9C1 is a genuine Na+/H+ exchanger gated by voltage. The cellular messenger cAMP shifts the voltage range of activation. Mutations in the transport domain, the VSD, or the CNBD strongly affect Na+/H+ exchange, voltage gating, or cAMP sensitivity, respectively. Our results establish SLC9C1 as a phylogenetic chimaera that combines the ion-exchange mechanism of solute carriers with the gating mechanism of ion channels. Classic SLCs slowly readjust changes in the intra- and extracellular milieu, whereas voltage gating endows the Na+/H+ exchanger with the ability to produce a rapid pH response that enables downstream signaling events.

PMID: 30022052 [PubMed - indexed for MEDLINE]

Categories: pubmed

Development of the sea urchin Heliocidaris crassispina from Hong Kong is robust to ocean acidification and copper contamination.

Thu, 12/13/2018 - 09:08
Related Articles

Development of the sea urchin Heliocidaris crassispina from Hong Kong is robust to ocean acidification and copper contamination.

Aquat Toxicol. 2018 Dec;205:1-10

Authors: Dorey N, Maboloc E, Chan KYK

Abstract
Metallic pollution is of particular concern in coastal cities. In the Asian megacity of Hong Kong, despite water qualities have improved over the past decade, some local zones are still particularly affected and could represent sinks for remobilization of labile toxic species such as copper. Ocean acidification is expected to increase the fraction of the most toxic form of copper (Cu2+) by 2.3-folds by 2100 (pH ≈7.7), increasing its bioavailability to marine organisms. Additionally, multiple stressors are likely to exert concomitant effects (additive, synergic or antagonist) on the organisms living in the sea. Here, we tested the hypothesis that copper-contaminated waters are more toxic to sea urchin larvae under future pH conditions. We exposed sea urchin embryos and larvae to two low-pH and two copper treatments (0.1 and 1.0 μM) in three separate experiments. Over the short time typically used for toxicity tests (up to 4-arm plutei, i.e. 3 days), larvae of the sea urchin Heliocidaris crassispina were robust and survived the copper levels present in Hong Kong waters today (≤0.19 μM) as well as the average pH projected for 2100. We, however, observed significant mortality with lowering pH in the longer, single-stressor experiment (Expt A: 8-arm plutei, i.e. 9 days). Abnormality and arm asymmetry were significantly increased by pH or/and by copper presence (depending on the experiment and copper level). Body size (d3; but not body growth rates in Expt A) was significantly reduced by both lowered pH and added copper. Larval respiration (Expt A) was doubled by a decrease at pHT from 8.0 to 7.3 on d6. In Expt B1.0 and B0.1, larval morphology (relative arm lengths and stomach volume) were affected by at least one of the two investigated factors. Although the larvae appeared robust, these sub-lethal effects may have indirect consequences on feeding, swimming and ultimately survival. The complex relationship between pH and metal speciation/uptake is not well-characterized and further investigations are urgently needed to detangle the mechanisms involved and to identify possible caveats in routinely used toxicity tests.

PMID: 30296660 [PubMed - indexed for MEDLINE]

Categories: pubmed

Gene expression across tissues, sex, and life stages in the sea urchin Tripneustes gratilla [Toxopneustidae, Odontophora, Camarodonta].

Wed, 12/12/2018 - 09:07
Related Articles

Gene expression across tissues, sex, and life stages in the sea urchin Tripneustes gratilla [Toxopneustidae, Odontophora, Camarodonta].

Mar Genomics. 2018 Oct;41:12-18

Authors: Láruson ÁJ, Coppard SE, Pespeni MH, Reed FA

Abstract
The pan-tropical sea urchin Tripneustes gratilla is an ecologically and economically important shallow water algal grazer. The aquaculture of T. gratilla has spurred growing interest in the population biology of the species, and by extension the generation of more molecular resources. To this purpose, de novo transcriptomes of T. gratilla were generated for two adults, a male and a female, as well as for a cohort of approximately 1000 plutei larvae. Gene expression profiles of three adult tissue samples were quantified and compared. These samples were of gonadal tissue, the neural ring, and pooled tube feet and pedicellariae. Levels of shared and different gene expression between sexes, as well as across functional categories of interest, including the immune system, toxins, genes involved in fertilization, and sensory genes are highlighted. Differences in expression of isoforms between the sexes and Sex determining Region Y-related High Mobility Group box groups is observed. Additionally an expansion of the tumor suppressor DMBT1 is observed in T. gratilla when compared to the annotated genome of the sea urchin Strongylocentrotus purpuratus. The draft transcriptome of T. gratilla is presented here in order to facilitate more genomic level analysis of emerging model sea urchin systems.

PMID: 30064945 [PubMed - indexed for MEDLINE]

Categories: pubmed

AID/APOBEC-like cytidine deaminases are ancient innate immune mediators in invertebrates.

Wed, 12/12/2018 - 09:07
Related Articles

AID/APOBEC-like cytidine deaminases are ancient innate immune mediators in invertebrates.

Nat Commun. 2018 05 16;9(1):1948

Authors: Liu MC, Liao WY, Buckley KM, Yang SY, Rast JP, Fugmann SD

Abstract
In the course of both innate and adaptive immunity, cytidine deaminases within the activation induced cytidine deaminase (AID)/apolipoprotein B editing complex (APOBEC) family modulate immune responses by mutating specific nucleic acid sequences of hosts and pathogens. The evolutionary emergence of these mediators, however, seems to coincide precisely with the emergence of adaptive immunity in vertebrates. Here, we show a family of genes in species within two divergent invertebrate phyla-the echinoderm Strongylocentrotus purpuratus and the brachiopod Lingula anatina-that encode proteins with similarities in amino acid sequence and enzymatic activities to the vertebrate AID/APOBECs. The expression of these invertebrate factors is enriched in tissues undergoing constant, direct interactions with microbes and can be induced upon pathogen challenge. Our findings suggest that AID/APOBEC proteins, and their function in immunity, emerged far earlier than previously thought. Thus, cytidine deamination is probably an ancient innate immune mechanism that predates the protostome/deuterostome divergence.

PMID: 29769532 [PubMed - indexed for MEDLINE]

Categories: pubmed

Effects of the toxic benthic dinoflagellate Ostreopsis cf. ovata on fertilization and early development of the sea urchin Lytechinus variegatus.

Wed, 12/12/2018 - 09:07
Related Articles

Effects of the toxic benthic dinoflagellate Ostreopsis cf. ovata on fertilization and early development of the sea urchin Lytechinus variegatus.

Mar Environ Res. 2018 Apr;135:11-17

Authors: Neves RAF, Contins M, Nascimento SM

Abstract
Blooms of the benthic dinoflagellate Ostreopsis cf. ovata have been recorded with increasing frequency, intensity and geographic distribution. This dinoflagellate produces potent toxins that may cause mortality of marine invertebrates. Adults of sea urchins are commonly affected by O. cf. ovata exposure with evidence of spines loss and high mortality during periods of high dinoflagellate abundances. Here, we report on the effects of the toxic dinoflagellate O. cf. ovata on fertilization and early development of the sea urchin Lytechinus variegatus, a key ecological herbivore. Lytechinus variegatus eggs and sperm were experimentally exposed to different concentrations of Ostreopsis cf. ovata (4, 40, 400, and 4000 cells ml-1) to test the hypothesis that fertilization success, embryonic and larval development of the sea urchin are negatively affected by the toxic dinoflagellate even at low abundances. Reduced fertilization, developmental failures, embryo and larval mortality, and occurrence of abnormal offspring were evident after exposure to O. cf. ovata. Fertilization decreased when gametes were exposed to high O. cf. ovata abundances (400 and 4000 cells ml-1), but just the exposure to the highest abundance significantly reduced fertilization success. Sea urchin early development was affected by O. cf. ovata in a dose-dependent way, high dinoflagellate abundances fully inhibited the early development of L. variegatus. Ostreopsis cf. ovata significantly increased the mortality of sea urchin eggs and embryos in the first hours of exposure (∼1-3 h), regardless of dinoflagellate abundance. Abundances of 400 and 4000 O. cf. ovata cells ml-1 induced significantly higher mortality on sea urchin initial stages in the first hours, and no egg or embryo was found in these treatments after 18 h of incubation. The early echinopluteus larva was only reached in the control and in treatments with low Ostreopsis cf. ovata abundances (4 and 40 cells ml-1). The exposure to O. cf. ovata led to significantly higher occurrence of skeletal anomalies in the early larva of L. variegatus. Interactions of sea urchin gametes and Ostreopsis cells may naturally occur in coastal areas due to the match between O. cf. ovata blooms and L. variegatus reproductive period. Reduced larval density and increased larval abnormalities were observed even at low abundances (4 and 40 cells ml-1) frequently found in tropical environments all year round. The chronic exposure to O. cf. ovata could significantly impact larval fitness, thus compromising recruitment success, and highlight the negative effects of benthic HABs on sea urchin populations and its possible broader ecological implications.

PMID: 29402518 [PubMed - indexed for MEDLINE]

Categories: pubmed

Sulfated fucans and a sulfated galactan from sea urchins as potent inhibitors of selectin-dependent hematogenous metastasis.

Fri, 11/16/2018 - 08:23
Related Articles

Sulfated fucans and a sulfated galactan from sea urchins as potent inhibitors of selectin-dependent hematogenous metastasis.

Glycobiology. 2018 06 01;28(6):427-434

Authors: Teixeira FCOB, Kozlowski EO, Micheli KVA, Vilela-Silva ACES, Borsig L, Pavão MSG

Abstract
Metastasis is responsible for the majority of cancer-associated deaths, though only a very small number of tumor cells are able to efficiently complete all the steps of that process. Tumor cell survival in the bloodstream is one of the limiting aspects of the metastatic cascade. The formation of tumor cell-platelet complexes that promote tumor cell survival is facilitated by the binding of P-selectin on activated platelets to sialyl Lewis-containing oligosaccharides on the surface of tumor cells. Inhibition of this interaction has been shown to attenuate metastasis. Heparin is a potent selectin inhibitor and is capable to block platelet-tumor cell complex formation, thereby attenuating metastasis. Similarly, other sulfated polysaccharides isolated from marine invertebrates attenuate metastasis by a P-selectin-mediated mechanism. In this work, we investigated the selectin-dependent antimetastatic activity of sea urchin sulfated polysaccharides with slight structural differences: a sulfated fucan from Strongylocentrotus franciscanus; a sulfated fucan from Strongylocentrotus droebachiensis; and a sulfated galactan from Echinometra lucunter. The results demonstrate that these fucans and the galactan have different antiselectin activities despite being very similar molecules. Therefore, they may be interesting tools for studies on the structure-function relationship or even for future treatments.

PMID: 29522135 [PubMed - indexed for MEDLINE]

Categories: pubmed

Boveri's research at the Zoological Station Naples: Rediscovery of his original microscope slides at the University of Würzburg.

Fri, 10/26/2018 - 08:46
Related Articles

Boveri's research at the Zoological Station Naples: Rediscovery of his original microscope slides at the University of Würzburg.

Mar Genomics. 2018 Jul;40:1-8

Authors: Scheer U

Abstract
Eric Davidson once wrote about Theodor Boveri: "From his own researches, and perhaps most important, his generalized interpretations, derive the paradigms that underlie modern inquiries into the genomic basis of embryogenesis" (Davidson, 1985). As luck would have it, the "primary data" of Boveri's experimental work, namely the microscope slides prepared by him and his wife Marcella during several stays at the Zoological Station in Naples (1901/02, 1911/12 and 1914), have survived at the University of Würzburg. More than 600 slides exist and despite their age they are in a surprisingly good condition. The slides are labelled and dated in Boveri's handwriting and thus can be assigned to his published experimental work on sea urchin development. The results allowed Boveri to unravel the role of the cell nucleus and its chromosomes in development and inheritance. Here, I present an overview of the slides in the context of Boveri's work along with photographic images of selected specimens taken from the original slides. It is planned to examine the slides in more detail, take high-resolution focal image series of significant specimens and make them online available.

PMID: 29426805 [PubMed - indexed for MEDLINE]

Categories: pubmed