Marine Annelid Research Articles

Ectoderm‐ and endomesoderm‐specific GATA transcription factors in the marine annelid Platynereis dumerilli

The GATA family of transcription factors appears to retain conserved roles in early germ layer patterning in most, if not all, animals; however, the number and structure of GATA factor genes varies substantially when different animal genomes are compared. Thus, the origin and relationships of invertebrate and vertebrate GATA factors, and their involvement in animal germ layer evolution, are unclear. We identified two highly conserved GATA factor genes in a marine annelid, the polychaete Platynereis dumerilii. A phylogenetic analysis indicates that the two Platynereis GATA factors are orthologous to the GATA1/2/3 and GATA4/5/6 subfamilies present in vertebrates. We also identified conserved motifs within each GATA class, and assigned the divergent Caenorhabditiselegans and Drosophila melanogaster GATA factor genes to the vertebrate classes. Similar to their vertebrate homologs, PdGATA123 mRNA expression was restricted to ectoderm, whereas PdGATA456 was detected only in endomesoderm. Finally, we identified in genome databases one GATA factor gene in each of two distantly related cnidarians that include motifs from both bilaterian GATA factor classes. Our results show that distinct orthologs of the two vertebrate GATA factor classes exist in a protostome invertebrate, suggesting that bilaterian GATA factors originated from GATA1/2/3 and 4/5/6 ancestral orthologs. Moreover, our results indicate that the GATA gene duplication and the functional divergence that led to these two ancestral GATA factor genes occurred after the split of the bilaterian stem group from the cnidarians.

Analysis of the immune-related transcriptome of a lophotrochozoan model, the marine annelid Platynereis dumerilii

BackgroundThe marine annelid Platynereis dumerilii (Polychaeta, Nereididae) has been recognized as a slow-evolving lophotrochozoan that attracts increasing attention as a valuable model for evolutionary and developmental research. Here, we analyzed its immune-related transcriptome. For targeted identification of immune-induced genes we injected bacterial lipopolysaccharide, a commonly used elicitor of innate immune responses, and applied the suppression subtractive hybridization technique that selectively amplifies cDNAs of differentially expressed genes.ResultsSequence analysis of 288 cDNAs revealed induced expression of numerous genes whose potential homologues from other animals mediate recognition of infection (e.g. complement receptor CD35), signaling (e.g. myc and SOCS), or act as effector molecules like ferritins and the bactericidal permeability-increasing protein. Interestingly, phylogenetic analyses implicate that immune-related genes identified in P. dumerilii are more related to counterparts from Deuterostomia than are those from Ecdysozoa, similarly as recently described for opsin and intron-rich genes.ConclusionObtained results may allow for a better understanding of Platynereis immunity and support the view that P. dumerilii represents a suitable model for analyzing immune responses of Lophotrochozoa.

Hedistin: A novel antimicrobial peptide containing bromotryptophan constitutively expressed in the NK cells-like of the marine annelid, Nereis diversicolor

A novel antimicrobial peptide, named hedistin was identified from the coelomocytes of Nereis diversicolor. Hedistin shows no obvious similarities with other known peptides and constitutes the first antimicrobial peptide containing bromotryptophans demonstrated in annelids. cDNA and mass spectrometry analysis revealed that, upon bacteria challenge, this peptide is secreted following processing of a precursor containing a signal peptide and prosequences. Hedistin was shown to possess an activity against a large spectrum of bacteria including the methicillin resistant Staphylococcus aureus and Vibrio alginolyticus. The gene was demonstrated to be constitutively and exclusively expressed in circulating NK cells like known to play an important role in the immunity of the sand worm. These data contrast with those observed in another annelid, the leech, in which genes coding for antimicrobial peptides are upregulated in a specific tissue and peptides are rapidly released into the hemolymph after septic injury.

Pushing Back the Expansion of Introns in Animal Genomes

In a recent paper in Science, surveyed the position of introns in 30 genes of a marine annelid and showed that over 60% of the introns occupy positions identical to those in human homologs. In contrast, both human and marine annelid genes share only 30% of their introns with other invertebrates. These observations suggest that the common ancestor of most animal phyla had intron-rich genes and reinforce the notion that introns proliferated early in the evolutionary history of eukaryotes.

Origin and properties of cytoplasmic and mitochondrial isoforms of taurocyamine kinase

Taurocyamine kinase (TK) is a member of the highly conserved family of phosphagen kinases that includes creatine kinase (CK) and arginine kinase. TK is found only in certain marine annelids. In this study we used PCR to amplify two cDNAs coding for TKs from the polychaete Arenicola brasiliensis, cloned these cDNAs into the pMAL plasmid and expressed the TKs as fusion proteins with the maltose-binding protein. These are the first TK cDNA and deduced amino acid sequences to be reported. One of the two cDNA-derived amino acid sequences of TKs shows a high amino acid identity to lombricine kinase, another phosphagen kinase unique to annelids, and appears to be a cytoplasmic isoform. The other sequence appears to be a mitochondrial isoform; it has a long N-terminal extension that was judged to be a mitochondrial targeting peptide by several on-line programs and shows a higher similarity in amino acid sequence to mitochondrial creatine kinases from both vertebrates and invertebrates. The recombinant cytoplasmic TK showed activity for the substrates taurocyamine and lombricine (9% of that of taurocyamine). However, the mitochondrial TK showed activity for taurocyamine, lombricine (30% of that of taurocyamine) and glycocyamine (7% of that of taurocyamine). Neither TK catalyzed the phosphorylation of creatine. Comparison of the deduced amino acid sequences of mitochondrial CK and TK indicated that several key residues required for CK activity are lacking in the mitochondrial TK sequence. Homology models for both cytoplasmic and mitochondrial TK, constructed using CK templates, provided some insight into the structural correlation of differences in substrate specificity between the two TKs. A phylogenetic analysis using amino acid sequences from a broad spectrum of phosphagen kinases showed that annelid-specific phosphagen kinases (lombricine kinase, glycocyamine kinase and cytoplasmic and mitochondrial TKs) are grouped in one cluster, and form a sister-group with CK sequences from vertebrate and invertebrate groups. It appears that the annelid-specific phosphagen kinases, including cytoplasmic and mitochondrial TKs, evolved from a CK-like ancestor(s) early in the divergence of the protostome metazoans. Furthermore, our results suggest that the cytoplasmic and mitochondrial isoforms of TK evolved independently.

Arenicolsterol A, a Novel Cytotoxic Enolic Sulfated Sterol from a Marine Annelid Arenicola cristata

AbstractMarine organisms are the important source of the bioactive metabolites. A novel enolic sulfated sterol, arenicolsterol A, has been isolated from a marine annelid Arenicola cristata collected in the coast of Mainland of China. The structure was elucidated using all sorts of spectroscopic data including ESIMS, 1D and 2D NMR etc. The cytotoxic bioactivity of this sterol was evaluated by MTT assay. It could inhibit the growth of human cervix cancer cell line (Hela) and human non‐small cell lung cancer cell line (NCI‐h6) with IC50 of (3.1±0.6) µg/mL and (7.6±0.8) µg/mL.

Bromophenol accumulation and sediment contamination by the marine annelids Notomastus lobatus and Thelepus crispus

The occurrence of bromophenols in Notomastus lobatus and Thelepus crispus and associated sediment and porewater was determined. 4-Bromophenol, 2,4-dibromophenol, and 2,4,6-tribromophenol were identified in N. lobatus with the highest concentrations occurring in the anterior and posterior abdomen and substantially less in the thorax (345, 209, and 6.6 μg/ml of worm, respectively). The concentration of dibromobenzyl alcohol was highest in the tail (last 15 setigers) of T. crispus (1.02 mg/ml of worm), but did not differ among body parts as the bromophenols did in N. lobatus. Concentrations in sediments were significantly reduced from those in the worms and decreased from the inner burrow lining out to 5 cm from N. lobatus burrows. Similarly for T. crispus, concentrations of dibromobenzyl alcohol in the surrounding sediments and porewater were low and increased with proximity to the burrow. For both species, concentrations in surface sediment (upper 1 cm) did not differ from those at 6 cm depth. Several lines of evidence indicate that these compounds are produced by the worms and hence their presence in sediments is derived from the worms. The contamination of sediment by these bromophenols has important implications for the structure and activities of benthic-associated communities.

Determining the purity of samples from natural products by coupling HPLC and CCD spectrometry

Isolation and identification of natural products is a very important and active research field. However, establishing the purity of the samples during the isolation process is quite difficult, especially when the retention times are similar for two desired components in HPLC. Although some technologies, e.g. MS and NMR, offer effective ways of obtaining purity information about the samples, the expensive instrumentation required or the off-line nature of coupling (generally speaking) make purity analysis somewhat inconvenient. In this paper, an on-line analytical system coupling HPLC and a CCD spectrometer for determination of purity for each eluate was developed in a thin layer spectrometric cell. The effectiveness of the system was demonstrated by differentiating Tanshinone I, Tanshinone IIA, and their mixture. The time-resolved UV-Vis spectra promptly revealed significant differences between the three samples while conventional single wavelength detection (CSWLD) could not. The system was then used to distinguish two steroid compounds which behaved as a single component in CSWLD. The compounds were isolated from a Chinese marine invertebrate animal, a marine annelid, Arenicola cristata, referred to here as Stimpson. The method reported here provided an efficient, convenient, fast, and inexpensive approach holding promise for on-line determination of the purity of samples isolated from natural products.

Preface

A necessary limitation of any compilation on eye development is precisely its strength: the field is so broad and intensively studied that it is not possible to do it justice in one issue. Eyes are widely distributed and diverse. Simple organelle eyespots exist in protozoa and unicellular alga, and highly simplified eyes are present in larvae of sponges and jellyfish. Adult cubomedusan jellyfish have sophisticated eyes (ocelli) with ciliated photoreceptors (like vertebrates) and cellular lenses as well as lens-less ocelli; ancient flatworms, marine annelid worms and the protochordate ascidian larva have complex eyes with a rudimentary lens, photoreceptors and pigment cells. Insects have both lens-containing ocelli like the jellyfish and compound eyes that comprise hundreds of separate facets, the ommatidia, each with their own few rhabdomeric photoreceptors. Some shrimps have compound eyes to detect polarizing signals from each other, while other crustacea use specialized eyes to capture stray photons created by thermal vents in the depths of the ocean. Scallops use rows of mirrored, camera-type eyes with lenses along the mantle that cast focussed images on double retinas using separate phototransducing pathways to feed or evade prey. Salmon have specialized cones in their retina that appear transiently in geometric patterns to orient polarized light for the fresh water stint of their extensive migrations. The eyes of the 'four-eyed' surface fish, Anableps, are divided into a dorsal half used in air above the water surface and a ventral half submerged in water; each half uses the same lens but has a separate cornea and retina. Mice see shades of grey and ultraviolet; eagles and butterflies see brilliant color. The human eye serves us well, but we lack the resolution of the eagle, or the night vision of the owl, or the ultraviolet vision of the mouse and insects. These are but a sprinkling of eyes populating our planet. This Special Issue of The International Journal of Developmental Biology touches on the development of some of these remarkable eyes, regrettably few, but we hope it kindles your interest to learn more.

Interesting Product Formation During O‐Alkylation and Subsequent Rearrangement of Two Building Blocks of Dibromotyrosine Based Natural Products.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Crystal structures of unligated and CN-ligated Glycera dibranchiata monomer ferric hemoglobin components III and IV.

Erythrocytes of the marine annelid, Glycera dibranchiata, contain a mixture of monomeric and polymeric hemoglobins. There are three major monomer hemoglobin components, II, III, IV (also called GMH2, 3, and 4), that have been highly purified and well characterized. We have now crystallized GMH3 and GMH4 and determined their structures to 1.4-1.8 A resolution. The structures were determined for these two monomer hemoglobins in the oxidized (Fe3+, ferric, or met-) forms in both the unligated and cyanide-ligated states. This work differs from two published, refined structures of a Glycera dibranchiata monomer hemoglobin, which has a sequence that is substantially different from any bona fide major monomer hemoglobins (GMH2, 3, or 4). The high-resolution crystal structures (presented here) and the previous NMR structure of CO-ligated GMH4, provide a basis for interpreting structure/function details of the monomer hemoglobins. These details include: (1) the strong correlation between temperature factor and NMR dynamics for respective protein forms; (2) the unique nature of the HisE7Leu primary sequence substitutions in GMH3 and GMH4 and their impact on cyanide ion binding kinetics; (3) the LeuB10Phe difference between GMH3 and GMH4 and its impact on ligand binding; and (4) elucidation of changes in the structural details of the distal and proximal heme pockets upon cyanide binding.

Molecular cloning and characterization of a gene encoding a 13.1 kDa antigenic protein of Naegleria fowleri.

An antigen-related gene was cloned from a cDNA expression library of Naegleria fowleri by immunoscreening with sera obtained from mice that were either immunized with an amoebic lysate or infected with trophozoites. The coding nucleotide sequence of the cloned gene consisted of 357 bases that were translated into 119 amino acids. This gene was designated as nfa1. The predicted amino acid sequence of Nfa1 protein has two potential glycosylation and three potential phosphorylation sites, and its predicted secondary structure consists of four helices and three corners. The deduced amino acid sequence of Nfa1 protein shares 43% identity with the myohemerythrin (myoHr) protein from a marine annelid, Nereis diversicolor, including 100% identity in conserved regions and iron-binding residues. A phylogenetic tree constructed from amino acid sequences placed the N. fowleri Nfa1 protein outside of a cluster of myoHr proteins from eight invertebrates. A purified recombinant protein that migrated as a 13.1 kDa species in SDS-PAGE was produced. This recombinant protein exhibited a strong immunoreactivity with infected, immune, and anti-Nfal sera. In addition, an anti-Nfa1 serum reacted with an amoeba lysate in immunoblotting analysis. The present nfal gene encoding the myoHr-like protein is the first myoHr gene cloned from protozoa, and the Nfal antigen may be useful in diagnostic studies

Structural Characterization of a Novel Series of Fucolipids from the Marine Annelid, Pseudopotamilla occelata.

A novel series of fucolipids, provisionally named CPS and CHS in the previous study, was obtained from whole tissues of the marine annelid, Pseudopotamilla occelata. The structures of these fucolipids were determined by compositional analysis, methylation analysis, gasliquid chromatography, gas chromatograph-mass spectrometry, proton nuclear magnetic resonance spectroscopy, and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. The structures were shown to be Xylβ1-4Fucα1-3GlcNAcβ1-3Galβ1-4Glcβ1-1Cer (CPS1) and Gal2Meα1-3Fucα1-3GlcNAcβ1-3Galβ1-4Glcβ1-1Cer (CPS2) for CPS, and Xylβ1-4 (Gal2Meα1-3) Fucα1-3GlcNAcβ1-3Galβ1-4Glcβ1-1Cer for CHS, respectively. They were structurally related to the previously described ceramide trisaccharide (GlcNAcβ1-3Galβ1-4Glcβ1-1Cer, Amino-CTH) except that a fucose-containing di- and/or trisaccharides were linked to the N-acetylglucosamine residue of the latter lipid. The predominant fatty acids were monoenoic acids, C20:1- and C22:1 acids amounting to about 80% of the total acids, and octadeca-4-sphingenine was the sole sphingoid base. The fatty acid and sphingoid base compositions showed nearly the same distribution in these fucolipids.

A scaleworm's setal snorkel

Abstract. Setae of the first segment of the marine annelid Sthenelais berkeleyi (family Sigalionidae) are arranged in the shape of an antero‐dorsally directed tube. When the worm is in resting position buried in sediment, this setal tube projects slightly from the sediment surface. A current of water is drawn into it by cilia on the parapodia of the first segment. The water is then diverted to a pair of lateral spaces between the body wall and elytra, moved posteriorly in these spaces along the length of the body by segmental cilia, and eventually exits posteriorly or ventrally. This flow permits the worm to respire while remaining buried and immobile for long periods of time, waiting for prey to move over the sediment near it. Setae of the first segment are probably used as snorkels in some other infaunal sigalionids as well.

The Colours of Life: An Introduction to the Chemistry of Porphyrins and Related Compounds. Lionel R. Milgrom

Previous articleNext article No AccessNew Biological BooksThe Colours of Life: An Introduction to the Chemistry of Porphyrins and Related Compounds. Lionel R. Milgrom Dabney W. DixonDabney W. Dixon Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The Quarterly Review of Biology Volume 75, Number 1Mar., 2000 Published in association with Stony Brook University Article DOIhttps://doi.org/10.1086/393271 Views: 7Total views on this site Citations: 4Citations are reported from Crossref Copyright 2000 The University of ChicagoPDF download Crossref reports the following articles citing this article:Knowledge Siyabonga Ndlovu, Makwena Justice Moloto, Kutloano Edward Sekhosana, Thabo Thokozani Innocent Nkambule, Muthumuni Managa Porphyrins developed for photoinactivation of microbes in wastewater, Environmental Science and Pollution Research 30, no.55 (Dec 2022): 11210–11225.https://doi.org/10.1007/s11356-022-24644-8Baokun Liang, Yingying Zhang, Christopher Leist, Zhaowei Ou, Miroslav Položij, Zhiyong Wang, David Mücke, Renhao Dong, Zhikun Zheng, Thomas Heine, Xinliang Feng, Ute Kaiser, Haoyuan Qi Optimal acceleration voltage for near-atomic resolution imaging of layer-stacked 2D polymer thin films, Nature Communications 13, no.11 (Jul 2022).https://doi.org/10.1038/s41467-022-31688-4Biyang Hu, Qi Li, Hong Yu, Shaojun Du Identification and characterization of key haem pathway genes associated with the synthesis of porphyrin in Pacific oyster (Crassostrea gigas), Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology 255 (Aug 2021): 110595.https://doi.org/10.1016/j.cbpb.2021.110595Maria Leonor Santos, Mariaelena D’Ambrosio, Ana P. Rodrigo, A. Jorge Parola, Pedro M. Costa A Transcriptomic Approach to the Metabolism of Tetrapyrrolic Photosensitizers in a Marine Annelid, Molecules 26, no.1313 (Jun 2021): 3924.https://doi.org/10.3390/molecules26133924

Characterization of a new variant DNA (cytosine-5)-methyltransferase unable to methylate double stranded DNA isolated from the marine annelid worm Chaetopterus variopedatus

The enzyme S-adenosylmethionine-DNA (cytosine-5)-methyltransferase has been identified, first time for invertebrates, in embryos of the marine polychaete annelid worm Chaetopterus variopedatus. The molecule has been isolated from embryos at 15 h of development. It is a single peptide of about 200 kDa molecular weight, cross-reacting with antibodies against sea urchin DNA methyltransferase. The enzymatic properties of the molecule are similar to those of Dnmt1 methyltransferases isolated from other organisms, but with the peculiarity to be unable to make ‘de novo’ methylation on double stranded DNA.

Structural Characterization of Neutral Glycosphingolipids, Mono-, Di- and Triglycosylceramides, from the Marine Annelid, Pseudopotamilla occelata

Neutral glycosphingolipids were extracted from the marine annelid, Pseudopotamilla occelata and separated into five fractions (CMS1, CMS2, CDS1, CDS2 and CTS) by their modes of column chromatography, ion exchange Sephadex (QAE-Sephadex), magnesium silicate (Florisil) and silicic acid (Iatrobeads). The chemical structures of the glycolipids in each fraction were determined by compositional analysis, methylation analysis, exoglycosidase cleavage, gas-liquid chromatography, gas chromatograph-mass spectrometry and matrix-assisted laser desorption ionization time-of-flight mass spectrometry, by which sugar, sphingoid and fatty acid compositions were clarified. Based on the results, their structures were proposed as Glcβ1-1ceramide and Galβ1-1ceramide (1.00 : 0.16) for CMS1, Glcβ 1-1ceramide for CMS2, Galα 1-4Galβ 1-1ceramide for CDS1, Ga1β 1-4G1cβ1-1ceramide for CDS2, and GlcNAcβ 1-3Galβ 1-4Glcβ 1-1ceramide for CTS. In the aliphatic moiety, the sphingoid component of all glycolipids was found to consist solely of octadeca-4-sphingenine. The fatty acid components of CMS1 and CDS1, or CDS2 and CTS were quite similar, consisting mainly of 16 : 0-, 17 : 0- and 18 : 0-acids, or 20 : 1- and 22 : 1-acids. The fatty acid components of CMS2 differed markedly from those of other glycolipids, and consisted primarily of 2-hydroxy 16 : 0-, 17 : 0- and 18 : 0-acids.Thin-layer chromatography and the results of sugar analysis indicated the presence of new glycolipids, penta- and hexaglycosylceramides possessing fucose, xylose and 2- (ο-methyl) galactose as additional sugar components. No glycosphingolipid component corresponding to tetraglycosylceramide could be detected by the present analyses.

Genome methylation of the marine annelid worm Chaetopterus variopedatus: methylation of a CpG in an expressed H1 histone gene

Hydrolysis by methylation-dependent restriction enzymes shows that the genomic DNA of the polychaete annelid worm Chaetopterus variopedatus is methylated. Electrophoretic analyses of the digestion products indicate that the degree of methylation is lower in adult tissues than in sperm and embryonic DNA. 5-Methylcytosine was identified by HPLC, absorption spectroscopy and mass spectrometry analyses of free bases obtained by acid hydrolysis of the DNA. An average value of 1.6% methylated cytosines was determined in sperm DNA. Partial methylation was also found in an actively expressed H1 histone gene. This is the first time that genomic DNA methylation is demonstrated to occur in a worm.

Development of an in vivo genotoxicity assay using the marine worm Platynereis dumerilii (Polychaeta: Nereidae)

An in vivo genotoxicity test system has been developed using the embryo-larval stages of the marine annelid, Playnereis dumerilii (Polychaeta: Nereidae). This species is representative of an ecologically important group of marine invertebrates, it is amenable to laboratory culture and has a well defined and stable karyotype ( 2n = 28) which is suitable for the analysis of a range of cytogenec endpoints, including chromosomal aberrations (CAs) and sister chromatid exchanges (SCEs). An evaluation of the cell cycle kinetics using the embryo-larval stages allowed selection of exposure times for cytogenetic work. Subsequently, 12-h-old embryos were exposed to reference mutagens, dissolved in sea water, in the presence of 5-bromodeoxyuridine (BrdU) for 12 h (SCE analysis) or 8 h (CA analysis at 15 ± 1°C, which time they had reached the first larval stage (20–24 h). Dose response-relationships for cytotoxicity, SCEs and CAs were observed for both direct acting mutagens (methyl methanesulfonate, mitomycin C) and mutagens which require metabolic activation (cyclophosphamide, benzo[a] pyrene ). The sensitivity of the embryo-larval stages of P. dumerilii to both direct and indirect acting mutagens, their suitability for laboratory culture, together with the presence of a good karyotype and chromosome morphology for cytogenetic analyses, makes this species a potentially valuable in vivo model for marine genotoxicity testing.

Detection of juvenile hormone‐active compounds by larvae of the marine annelid Capitella sp. I

Detection of juvenile hormone‐active compounds by larvae of the marine annelid Capitella sp. I