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Sample records for ascidian halocynthia roretzi

  1. Complete DNA sequence of the mitochondrial genome of the ascidian Halocynthia roretzi (Chordata, Urochordata).

    OpenAIRE

    Yokobori, S i; Ueda, T.; Feldmaier-Fuchs, G; Pääbo, S; Ueshima, R.; Kondow, A; Nishikawa, K.; Watanabe, K.

    1999-01-01

    The complete nucleotide sequence of the 14,771-bp-long mitochondrial (mt) DNA of a urochordate (Chordata)-the ascidian Halocynthia roretzi-was determined. All the Halocynthia mt-genes were found to be located on a single strand, which is rich in T and G rather than in A and C. Like nematode and Mytilus edulis mtDNAs, that of Halocynthia encodes no ATP synthetase subunit 8 gene. However, it does encode an additional tRNA gene for glycine (anticodon TCT) that enables Halocynthia mitochondria to...

  2. Taxonomy Icon Data: Halocynthia roretzi (Sea squirt) [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available .png http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Halocynthia+roretzi&t=L http://biosciencedbc.jp/taxonomy..._icon/icon.cgi?i=Halocynthia+roretzi&t=NL http://biosciencedbc.jp/taxonomy_icon.../icon.cgi?i=Halocynthia+roretzi&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Halocynthia+roretzi&t=N...S http://togodb.biosciencedbc.jp/togodb/view/taxonomy_icon_comment_en?species_id=183 ...

  3. Vascular Endothelial Growth Factor Receptor Family in Ascidians, Halocynthia roretzi (Sea Squirt). Its High Expression in Circulatory System-Containing Tissues

    OpenAIRE

    Saeed Samarghandian; Masabumi Shibuya

    2013-01-01

    The vascular endothelial growth factor (VEGF)-VEGF Receptor (VEGFR) system is an important pathway for regulation of angiogenesis. However, its evolutionary development, particularly the step from invertebrates to vertebrates, is still largely unknown. Here, we molecularly cloned the VEGFR-like gene from Halocynthia roretzi, a species belonging to the Tunicata, the chordate subphylum recently considered the sister group of vertebrates. The cDNA encoded a homolog of human VEGFR, including the ...

  4. Ascidian bioresources: common and variant chemical compositions and exploitation strategy - examples of Halocynthia roretzi, Styela plicata, Ascidia sp. and Ciona intestinalis.

    Science.gov (United States)

    Zhao, Yadong; Li, Jiebing

    2016-01-01

    To explore abundant marine ascidian bioresources, four species from two orders have been compared in their chemical compositions. After a universal separation of the animal body into two fractions, all tunics have been found rich in carbohydrate contents, while all inner body tissues are richer in proteins. Cellulose is present almost exclusively in the tunics and more in the order Stolidobranchia, while more sulfated polysaccharides are present in Phlebobranchia species. Almost all proteins are collagens with a high essential amino acid index and high delicious amino acid (DAA) content. All fractions also have high contents of good-quality fatty acids and trace minerals but low toxic element contents, with different sterols and glycosaminoglycans. There are species-specific characteristics observed for vanadium accumulation and sterol structures which are also meaningful for ascidian chemotaxonomy and resource exploitation. It is suggested that in addition to the present utilizations of tunics for cellulose production and of some species' inner body tissues as human food, one should explore all species' inner body tissues as human foods and all tunics as food or animal feed with the contained cellulose as dietary fiber. Collagens, sulfated polysaccharides, glycosaminoglycans, sterols and trace elements could be explored as byproducts for, e.g. pharmaceutical and chemical industries. PMID:27049617

  5. Roseovarius halocynthiae sp. nov., isolated from the sea squirt Halocynthia roretzi.

    Science.gov (United States)

    Kim, Young-Ok; Kong, Hee Jeong; Park, Sooyeon; Kang, So-Jung; Kim, Woo-Jin; Kim, Kyung-Kil; Oh, Tae-Kwang; Yoon, Jung-Hoon

    2012-04-01

    A Gram-negative, motile, ovoid- to rod-shaped bacterial strain, designated MA1-10T, was isolated from a sea squirt (Halocynthia roretzi) collected from the South Sea, Korea. Strain MA1-10T grew optimally at pH 7.0-8.0, at 30 °C and in the presence of 2 % (w/v) NaCl. In the neighbour-joining phylogenetic tree based on 16S rRNA gene sequences, strain MA1-10T clustered with Roseovarius crassostreae CV919-312T, with which it exhibited 97.1 % sequence similarity, at a bootstrap resampling value of 96.2 %. It exhibited 93.3-95.8 % 16S rRNA gene sequence similarity to the type strains of other recognized Roseovarius species. Strain MA1-10T contained Q-10 as the predominant ubiquinone and C18:1ω7c as the major fatty acid, which is consistent with data for the genus Roseovarius. The major polar lipids were phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, an unidentified aminolipid and an unidentified lipid. The DNA G+C content of strain MA1-10T was 55.4 mol%. Mean DNA-DNA relatedness between strain MA1-10T and R. crassostreae DSM 16950T was 13 %. Differential phenotypic properties, together with phylogenetic and genetic distinctiveness, demonstrated that strain MA1-10T could be distinguished from all recognized Roseovarius species. On the basis of the data presented, strain MA1-10T is considered to represent a novel species of the genus Roseovarius, for which the name Roseovarius halocynthiae sp. nov. is proposed; the type strain is MA1-10T (=KCTC 23462T=CCUG 60745T). PMID:21669917

  6. Ruegeria halocynthiae sp. nov., isolated from the sea squirt Halocynthia roretzi.

    Science.gov (United States)

    Kim, Young-Ok; Park, Sooyeon; Nam, Bo-Hye; Kang, So-Jung; Hur, Young Baek; Lee, Sang-Jun; Oh, Tae-Kwang; Yoon, Jung-Hoon

    2012-04-01

    A Gram-negative, non-motile, rod-shaped bacterial strain, designated MA1-6T, was isolated from a sea squirt (Halocynthia roretzi) collected from the South Sea, Korea, and was characterized to determine its taxonomic position. Strain MA1-6T grew optimally at pH 7.0-8.0, at 30 °C and in the presence of 2-3 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain MA1-6T fell within the clade comprising Ruegeria species and exhibited 95.3-96.5 % similarity to the type strains of recognized Ruegeria species. Strain MA1-6T contained Q-10 as the predominant ubiquinone and C18:1ω7c as the major fatty acid, which is consistent with data for Ruegeria species. The major polar lipids detected in strain MA1-6T and Ruegeria atlantica KCTC 12424T were phosphatidylcholine, phosphatidylglycerol, an unidentified aminolipid and an unidentified lipid. The DNA G+C content of strain MA1-6T was 58.6 mol%. Differential phenotypic properties, together with phylogenetic distinctiveness, demonstrated that strain MA1-6T can be distinguished from recognized Ruegeria species. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain MA1-6T is considered to represent a novel species of the genus Ruegeria, for which the name Ruegeria halocynthiae sp. nov. is proposed; the type strain is MA1-6T (=KCTC 23463T=CCUG 60744T). PMID:21669923

  7. Litoreibacter halocynthiae sp. nov., isolated from the sea squirt Halocynthia roretzi.

    Science.gov (United States)

    Kim, Young-Ok; Park, Sooyeon; Nam, Bo-Hye; Jung, Yong-Taek; Kim, Dong-Gyun; Lee, Jung-Sook; Lee, Sang-Jun; Yoon, Jung-Hoon

    2013-09-01

    A Gram-stain-negative, non-motile and coccoid, ovoid or rod-shaped bacterial strain, designated P-MA1-7(T), was isolated from a sea squirt (Halocynthia roretzi) collected from the South Sea, Korea. Strain P-MA1-7(T) grew optimally at 25 °C, at pH 7.0-8.0 and in the presence of 2-3% (w/v) NaCl. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain P-MA1-7(T) fell within the cluster comprising the type strains of four species of the genus Litoreibacter, exhibiting 16S rRNA gene sequence similarity values of 97.0-98.5% to these four type strains and less than 95.9% sequence similarity to the strains of the other species examined. Strain P-MA1-7(T) contained Q-10 as the predominant ubiquinone and C(18:1)ω7c as the predominant fatty acid. The major polar lipids of strain P-MA1-7(T) were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, one unidentified aminolipid and one unidentified lipid. The DNA G+C content of strain P-MA1-7(T) was 58.3 mol% and DNA-DNA relatedness values of strain P-MA1-7(T) with the type strains of the four species of the genus Litoreibacter were in the range of 8-21%. The differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain P-MA1-7(T) was separate from other species of the genus Litoreibacter. On the basis of these data, strain P-MA1-7(T) is considered to represent a novel species of the genus Litoreibacter, for which the name Litoreibacter halocynthiae sp. nov. is proposed. The type strain is P-MA1-7(T) ( =KCTC 32213(T) =CCUG 63416(T)). PMID:23524350

  8. Tenacibaculum halocynthiae sp. nov., a member of the family Flavobacteriaceae isolated from sea squirt Halocynthia roretzi.

    Science.gov (United States)

    Kim, Young-Ok; Park, Sooyeon; Nam, Bo-Hye; Jung, Yong-Taek; Kim, Dong-Gyun; Jee, Young-Ju; Yoon, Jung-Hoon

    2013-06-01

    A Gram-negative, non-spore-forming, aerobic, non-flagellated, non-gliding and rod-shaped bacterial strain, designated P-R2A1-2(T), was isolated from sea squirt (Halocynthia roretzi) collected from the South Sea, Korea. It grew optimally at 25-28 °C, at pH 7.0-8.0 and in the presence of 2 % (w/v) NaCl. Neighbour-joining phylogenetic tree based on 16S rRNA gene sequences revealed that the strain fell within the clade comprising Tenacibaculum species. Strain P-R2A1-2(T) exhibited the highest 16S rRNA gene sequence similarity values of 97.6, 97.2 and 97.0 % to Tenacibaculum aestuarii SMK-4(T), T. lutimaris TF-26(T) and T. aiptasiae a4(T), respectively, and of 94.5-96.8 % to the type strains of the other Tenacibaculum species. Strain P-R2A1-2(T) contained MK-6 as the predominant menaquinone and C16:1 ω7c and/or iso-C15:0 2-OH, iso-C15:0 3-OH and iso-C15:0 as the major fatty acids. The DNA G + C content of strain P-R2A1-2(T) was 30.7 mol % and its DNA-DNA relatedness values with the type strains of T. aestuarii, T. lutimaris and T. aiptasiae were 17 ± 4.2, 21 ± 6.1 and 16 ± 5.2 %, respectively. Differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that the novel strain is separate from other Tenacibaculum species. On the basis of the data presented, strain P-R2A1-2(T) is considered to represent a novel species of the genus Tenacibaculum, for which the name Tenacibaculum halocynthiae sp. nov. is proposed. The type strain is P-R2A1-2(T) (=KCTC 32262(T )= CCUG 63681(T)). PMID:23543245

  9. Colwellia meonggei sp. nov., a novel gammaproteobacterium isolated from sea squirt Halocynthia roretzi.

    Science.gov (United States)

    Kim, Young-Ok; Park, Sooyeon; Nam, Bo-Hye; Jung, Yong-Taek; Kim, Dong-Gyun; Yoon, Jung-Hoon

    2013-12-01

    A Gram-negative, non-spore-forming, aerobic, motile and rod-shaped or ovoid bacterial strain, designated MA1-3(T), was isolated from a sea squirt (Halocynthia roretzi) collected from the South sea in South Korea. Strain MA1-3(T) was found to grow optimally at 25 °C, at pH 7.0-8.0 and in the presence of 2.0 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences revealed that strain MA1-3(T) fell within the clade comprising Colwellia species, clustering coherently with the type strains of Colwellia aestuarii, Colwellia polaris and Colwellia chukchiensis, showing sequence similarity values of 97.2, 96.4 and 95.6 %, respectively. It exhibited 16S rRNA gene sequence similarity values of 93.9-96.1 % to the type strains of the other Colwellia species. Strain MA1-3(T) was found to contain Q-8 as the predominant ubiquinone and C16:1 ω7c and/or C16:1 ω6c, C16:0 and C16:1 ω9c as the major fatty acids. The DNA G+C content of strain MA1-3(T) was determined to be 39.1 mol% and its mean DNA-DNA relatedness value with the type strain of C. aestuarii was 13 ± 5.4 %. The differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that the novel strain is separated from other Colwellia species. On the basis of the data presented, strain MA1-3(T) is considered to represent a novel species of the genus Colwellia, for which the name Colwellia meonggei sp. nov. is proposed. The type strain is MA1-3(T) (=KCTC 32380(T) = CECT 8302(T)). PMID:24006188

  10. Two New Cholic Acid Derivatives from the Marine Ascidian-Associated Bacterium Hasllibacter halocynthiae

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    Sung Hun Kim

    2012-10-01

    Full Text Available The investigation of secondary metabolites in liquid cultures of a recently discovered marine bacterium, Hasllibacter halocynthiae strain KME 002T, led to the isolation of two new cholic acid derivatives. The structures of these compounds were determined to be 3,3,12-trihydroxy-7-ketocholanic acid (1 and 3,3,12-trihydroxy-7-deoxycholanic acid (2 through HRFABMS and NMR data analyses.

  11. Description of Litoreibacter meonggei sp. nov., isolated from the sea squirt Halocynthia roretzi, reclassification of Thalassobacter arenae as Litoreibacter arenae comb. nov. and emended description of the genus Litoreibacter Romanenko et al. 2011.

    Science.gov (United States)

    Kim, Young-Ok; Park, Sooyeon; Nam, Bo-Hye; Kang, So-Jung; Hur, Young-Baek; Kim, Dong-Gyun; Oh, Tae-Kwang; Yoon, Jung-Hoon

    2012-08-01

    A Gram-negative, non-motile and coccoid, ovoid or rod-shaped bacterial strain, designated MA1-1(T), was isolated from a sea squirt (Halocynthia roretzi) collected from the South Sea, Korea. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain MA1-1(T) is phylogenetically closely related to Litoreibacter species and to Thalassobacter arenae. It exhibited 16S rRNA gene sequence similarities of 97.3, 97.1 and 97.3% to the type strains of Litoreibacter albidus, Litoreibacter janthinus and T. arenae, respectively. Strain MA1-1(T) contained Q-10 as the predominant ubiquinone and C(18:1)ω7c as the predominant fatty acid. The polar lipid profile of strain MA1-1(T) was similar to those of the type strains of L. albidus and L. janthinus. T. arenae was found to be phylogenetically and chemotaxonomically more closely related to Litoreibacter species and strain MA1-1(T) than to Thalassobacter stenotrophicus, the type species of the genus Thalassobacter. The DNA G+C content of strain MA1-1(T) was 57.9 mol%, and DNA-DNA relatedness to the type strains of the two Litoreibacter species and T. arenae was 9-14%. Differential phenotypic properties, together with the observed phylogenetic and genetic distinctiveness, distinguished strain MA1-1(T) from the two Litoreibacter species and T. arenae. On the basis of the data presented, strain MA1-1(T) is considered to represent a novel species of the genus Litoreibacter, for which the name Litoreibacter meonggei sp. nov. is proposed. The type strain is MA1-1(T) ( = KCTC 23699(T)  = CCUG 61486(T)). In this study, it is also proposed that Thalassobacter arenae is reclassified as a member of the genus Litoreibacter, Litoreibacter arenae comb. nov. (type strain GA2-M15(T)  = DSM 19593(T)  = KACC 12675(T)). An emended description of the genus Litoreibacter is also presented. PMID:21984668

  12. RNA-seq-based metatranscriptomic and microscopic investigation reveals novel metalloproteases of Neobodo sp. as potential virulence factors for soft tunic syndrome in Halocynthia roretzi.

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    Ho Bin Jang

    Full Text Available Bodonids and trypanosomatids are derived from a common ancestor with the bodonids being a more primitive lineage. The Neobodonida, one of the three clades of bodonids, can be free-living, commensal or parasitic. Despite the ecological and evolutionary significance of these organisms, however, many of their biological and pathological features are currently unknown. Here, we employed metatranscriptomics using RNA-seq technology combined with field-emission microscopy to reveal the virulence factors of a recently described genus of Neobodonida that is considered to be responsible for ascidian soft tunic syndrome (AsSTS, but whose pathogenesis is unclear. Our microscopic observation of infected tunic tissues suggested putative virulence factors, enabling us to extract novel candidate transcripts; these included cysteine proteases of the families C1 and C2, serine proteases of S51 and S9 families, and metalloproteases grouped into families M1, M3, M8, M14, M16, M17, M24, M41, and M49. Protease activity/inhibition assays and the estimation of expression levels within gene clusters allowed us to identify metalloprotease-like enzymes as potential virulence attributes for AsSTS. Furthermore, a multimarker-based phylogenetic analysis using 1,184 concatenated amino acid sequences clarified the order Neobodo sp. In sum, we herein used metatranscriptomics to elucidate the in situ expression profiles of uncharacterized putative transcripts of Neobodo sp., combined these results with microscopic observation to select candidate genes relevant to pathogenesis, and used empirical screening to define important virulence factors.

  13. Ascidian gene-expression profiles

    OpenAIRE

    William R Jeffery

    2002-01-01

    With the advent of gene-expression profiling, a large number of genes can now be investigated simultaneously during critical stages of development. This approach will be particularly informative in studies of ascidians, basal chordates whose genomes and embryology are uniquely suited for mapping developmental gene networks.

  14. The ascidian prophenoloxidase activating system

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    M Cammarata

    2009-03-01

    Full Text Available Phenoloxidases/tyrosinases initiate melanin synthesis in almost all organisms, and are involved in different biological activities such as the colour change of human hair and the browning or blackening of fruit skin etc. In many invertebrates, defence reactions are linked to phenoloxidase activity and/or melanization. Contacts with foreign molecules are able to trigger the prophenoloxidase (proPO system that requires serine protease cleavage for activating the zymogen to phenoloxidase (PO. It is generally accepted that the proPO system is fully expressed in arthropods, and, recently, progress in the regulation of crustacean and insect proPO activation steps have been achieved. After cells were stimulated by components of pathogen associated molecular pattern (PAMP, proPO activation takes place via zimogenic serine proteinase in turn activated by PAMPs followed by cascade, spatial and temporal control.The proPO activating system plays a defensive role in arthropods, molluscs, annelids, ascidians and the cephalochordate Branchiostoma belcheri.In the present paper, we report on ascidian proPO system and related molecules, with particular focus on the biochemical, cellular and molecular aspects of the Ciona intestinalis, proPO system of circulating hemocytes from naïve ascidians as well as of body wall following LPS inflammatory challenge.

  15. Ecology of ascidians in the macrofouling community of New Mangalore Port

    Digital Repository Service at National Institute of Oceanography (India)

    Venkat, K.; Anil, A.C.; Khandeparker, D.C.; Mokashe, S.S.

    Ascidians constitute a major component of macrofouling community at the New Mangalore Port during the premonsoon season (February-May). The presence of ascidians in these waters is being reported for the first time. Ascidian recruitment...

  16. Ascidians from Rocas Atoll, northeast Brazil

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    Sandra Vieira Paiva; Ronaldo Ruy Oliveira-Filho; Tito Monteiro Da Cruz Lotufo

    2015-01-01

    Rocas Atoll is the only one of its kind in the South Atlantic—and the first Brazilian marine biological reserve. This is the first report about the ascidians from Rocas. A total of 12 species were found, 5 of them not hitherto described: Ascidia viridina sp. nov., Didemnum rochai sp. nov., Leptoclinides crocotulus sp. nov., Polysyncraton maurizeliae sp. nov., and Trididemnum rocasensis sp. nov.). One Caribbean species, Didemnum halimedae, was also discovered in the region for the first time. ...

  17. Ascidians from Rocas Atoll, northeast Brazil

    OpenAIRE

    Paiva, Sandra V.; Oliveira Filho, Ronaldo R. de; Lotufo, Tito M. da Cruz

    2015-01-01

    Rocas Atoll is the only one of its kind in the South Atlantic—and the first Brazilian marine biological reserve. This is the first report about the ascidians from Rocas. A total of 12 species were found, 5 of them not hitherto described: Ascidia viridina sp. nov., Didemnum rochai sp. nov., Leptoclinides crocotulus sp. nov., Polysyncraton maurizeliae sp. nov., and Trididemnum rocasensis sp. nov. One Caribbean species, Didemnum halimedae, was also discovered in the region for the first time. Fu...

  18. Genome Sequence of the Sponge-Associated Ruegeria halocynthiae Strain MOLA R1/13b, a Marine Roseobacter with Two Quorum-Sensing-Based Communication Systems.

    Science.gov (United States)

    Doberva, Margot; Sanchez-Ferandin, Sophie; Ferandin, Yoan; Intertaglia, Laurent; Croué, Julie; Suzuki, Marcelino; Lebaron, Philippe; Lami, Raphaël

    2014-01-01

    Ruegeria halocynthiae MOLA R1/13b is an alphaproteobacterium isolated from the Mediterranean sea sponge Crambe crambe. We report here the genome sequence and its annotation, revealing the presence of quorum-sensing genes. This is the first report of the full genome of a Ruegeria halocynthiae strain. PMID:25301648

  19. Genome Sequence of the Sponge-Associated Ruegeria halocynthiae Strain MOLA R1/13b, a Marine Roseobacter with Two Quorum-Sensing-Based Communication Systems

    OpenAIRE

    Doberva, Margot; Sanchez-Ferandin, Sophie; Ferandin, Yoan; Intertaglia, Laurent; Croué, Julie; Suzuki, Marcelino; Lebaron, Philippe; Lami, Raphaël

    2014-01-01

    International audience Ruegeria halocynthiae MOLA R1/13b is an alphaproteobacterium isolated from the Mediterranean sea sponge Crambe crambe. We report here the genome sequence and its annotation, revealing the presence of quorum-sensing genes. This is the first report of the full genome of a Ruegeria halocynthiae strain.

  20. Amino Alcohols from the Ascidian Pseudodistoma sp.

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    Tae Hyung Won

    2014-06-01

    Full Text Available Seven new amino alcohol compounds, pseudoaminols A–G (1–7, were isolated from the ascidian Pseudodistoma sp. collected off the coast of Chuja-do, Korea. Structures of these new compounds were determined by analysis of the spectroscopic data and from chemical conversion. The presence of an N-carboxymethyl group in two of the new compounds (6 and 7 is unprecedented among amino alcohols. Several of these compounds exhibited moderate antimicrobial activity and cytotoxicity, as well as weak inhibitory activity toward Na+/K+-ATPase.

  1. Changes in gelsolin expression during ascidian metamorphosis.

    Science.gov (United States)

    Ohtsuka, Y; Okamura, Y; Obinata, T

    2001-05-01

    Gelsolin is an actin regulatory protein that is expressed in a wide variety of tissues and is especially abundant in muscle and blood cells. The role of gelsolin during structural reorganization of the body, such as during metamorphosis or regeneration, is poorly understood. We analyzed changes in gelsolin expression during ascidian embryogenesis and metamorphosis using nucleic acid probes and a monoclonal antibody (AS23) specific for ascidian gelsolin; our results indicated that gelsolin is maternally provided and that its de novo gene transcription is initiated during the neurula stage. In the larva, gelsolin was detectable in specific types of nerve cells, i.e. the adhesive papillae, motor neurons and epidermal sensory neurons. During metamorphosis, the expression of gelsolin changes markedly: the expression is suppressed in nerve tissues after tail resorption but is induced in mesodermal tissues. Gelsolin accumulated in mesenchyme cells until the onset of tail resorption, and following tail resorption, these cells migrated to the tunic and differentiated into tunic cells with many fine processes. Migration of the mesenchyme cells into the tunic was completely inhibited by treatment with cytochalasin B. Gelsolin was colocalized with actin in tunic cells, suggesting that it is involved in the rearrangement of actin filaments during cell locomotion or morphogenesis. PMID:11455440

  2. The central nervous system of ascidian larvae.

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    Hudson, Clare

    2016-09-01

    Ascidians are marine invertebrate chordates. Their tadpole larvae contain a dorsal tubular nervous system, resulting from the rolling up of a neural plate. Along the anterior-posterior (A-P) axis, the central nervous system (CNS) is organized into a sensory vesicle, neck, trunk ganglion, and tail nerve cord and consists of approximately only 330 cells, of which around 100 are thought to be neurons. The organization of distinct neuronal cell types and neurotransmitter gene expression within the CNS has been described. The unique developmental mode of ascidians, with a small number of cells and a fixed cell division pattern, allows individual cells to be traced throughout development. This feature has led to the complete documentation of the cell lineages of certain cell types in the CNS. Thus, a step-by-step understanding of nervous system development from the initial stages of neural induction to the neurogenesis of individual neurons is a feasible goal. The genetic control of neural fate induction and early neural plate patterning are now well understood. The molecular mechanisms specifying the cholinergic neurons of the trunk ganglion as well as the pigment cells of the sensory organs are also well elucidated. In addition, studies have begun on the morphogenetic processes of neurulation. Remaining challenges include building an embryonic atlas integrating gene expression patterns, cell lineage, and neuronal cell types as well as developing the gene regulatory networks of cell fate specification and integrating them with the genetic control of morphogenesis. WIREs Dev Biol 2016, 5:538-561. doi: 10.1002/wdev.239 For further resources related to this article, please visit the WIREs website. PMID:27328318

  3. Genomics and developmental approaches to an ascidian adenohypophysis primordium.

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    Kano, Shungo

    2010-07-01

    Ascidians, which are the closest phylogenetic relatives to vertebrates, lack a distinct pituitary gland, which is the major endocrine gland in vertebrates. Nevertheless, for the past 130 years, it has been debated that the ascidian neural complex (NC) is homologous to the pituitary. Of the three major components of the NC, the neural gland (NG) has mainly been thought to be the ascidian counterpart of the pituitary. Recently, however, the ciliated funnel, and not the NG, was postulated to be the adenohypophysis (AH) primordium because it is likely derived from oral ectoderm, and because the expression of several placodal genes is comparable to their expression in vertebrates. An extensive in silico survey of the Ciona intestinalis genome sequence revealed that genes encoding pituitary hormones are absent in ascidians. Under the circumstances, this thesis attempts to find a path that shows that the AH primordium is recognizable in the ascidian by revisiting molecular and developmental data from recent public resources on C. intestinalis, and through the use of advanced bio-imaging techniques. A putative Ciona genetic pathway, which was constructed by referring to data from mammals, shows that only a patchwork of the genetic network exists to achieve terminal differentiation of the AH endocrine cells in the Ciona genome. Re-annotation on glycoprotein hormone related proteins, a GPA2/ARP and two GPB5/BRP ones previously reported, reveals that the GPA2 locus contains two splicing variants, and one variant likely formed a three-dimensional conformation similar to that of human GPA2. No clone of the GPB5/BRP1 locus has been isolated, and another candidate, BRP2, is unlikely to be a GPB5. Next, I argued a possibility that endocrine activities of Ciona species could be specialized in association with its short generation time, and I suggest that not only Ciona species but also other ascidians should be studied in order to understand ascidian endocrinology. Confocal images

  4. Ascidians and the plasticity of the chordate developmental program

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    Lemaire, Patrick; Smith, William C.; Nishida, Hiroki

    2008-01-01

    Little is known about the ancient chordates that gave rise to the first vertebrates, but the descendants of other invertebrate chordates extant at the time still flourish in the ocean. These invertebrates include the cephalochordates and tunicates, whose larvae share with vertebrate embryos a common body plan with a central notochord and a dorsal nerve cord. Tunicates are now thought to be the sister group of vertebrates. However, research based on several species of ascidians, a diverse and ...

  5. Genetic perspectives on the ascidian central nervous system

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    A Locascio

    2009-03-01

    Full Text Available In 2002, date of publication of the Ciona intestinalis genome, ascidians entered the post-genomic era. This tool had a fundamental role and has become the starting point for a series of new functional and genomic studies. Recently, great efforts have been done to characterize the genetic cascades of genes having a key role in early embryonic development and to draw the regulatory networks in which they are involved. In this review, we focused our attention on the last advances obtained in the attempt to clarify the complex molecular events governing ascidian central nervous system development with a special interest for anterior neural and sensory structures. We discussed the more recent theories on its early induction and late regionalization. In particular, we used some conserved genes fully or partially characterized as examples to compare ascidian and vertebrate central nervous system (CNS.By integrating the various results obtained with microarray, morpholino loss of function and promoter analyses, we showed that many progresses have been done to unravel the gene networks controlling early CNS induction and formation. Unfortunately, fewer advances have been done in the identification of the regulatory cascades controlling late CNS regionalization and sensory organs differentiation. Some results are discussed to point out the importance of fully characterizing also these specific regulatory cascades.

  6. Geographic ranges of ascidians from Antarctica and the southeastern Pacific

    Institute of Scientific and Technical Information of China (English)

    Dirk Schories; Karen Sanamyan; Nadja Sanamyan; Mara Jos Daz; Ignacio Garrido; Thomas Heran; Jorge Holtheuer; Gesche Kohlberg

    2015-01-01

    Historical and novel data on the geographic and bathymetric distribution of ascidians from Antarctic, Magellan and Chilean waters are compiled, and an inventory of taxa comprising 162 species reported over a 150 year period from the Antarctic region South Polar Province (SPP) compiled. The ascidian fauna from the South Shetland Islands (SSI) is compared with that of the Magellan region, Patagonia and the Chilean coast. We collected 46 ascidian species along the Chilean coast, and during four expeditions to King George Island (SSI) by SCUBA between 2003–2012. About 15% of King George Island (SSI) species are observed to occur also in shallow waters of southern Chile (SCL). Few species known from warm temperate southeastern Pacific (Northern Chile, NCL) waters are absent from the Chilean part of the Magellan Province (SCL). With most data contributed from the Chilean coast coming from the SCL, and with limited sampling having been undertaken at depths exceeding 100 m in the NCL, apparent differences in species richness along the Chilean coast could be attributabed to differential sampling effort. We detail 12 species from our Antarctic and Chilean collections in detail, including one, Diplosoma listerianum, not previously reported from Chilean waters, and the genus Botryllus, previously known from them on the basis of a single record.

  7. An otx/nodal regulatory signature for posterior neural development in ascidians.

    Directory of Open Access Journals (Sweden)

    Agnès Roure

    2014-08-01

    Full Text Available In chordates, neural induction is the first step of a complex developmental process through which ectodermal cells acquire a neural identity. In ascidians, FGF-mediated neural induction occurs at the 32-cell stage in two blastomere pairs, precursors respectively of anterior and posterior neural tissue. We combined molecular embryology and cis-regulatory analysis to unveil in the ascidian Ciona intestinalis the remarkably simple proximal genetic network that controls posterior neural fate acquisition downstream of FGF. We report that the combined action of two direct FGF targets, the TGFβ factor Nodal, acting via Smad- and Fox-binding sites, and the transcription factor Otx suffices to trigger ascidian posterior neural tissue formation. Moreover, we found that this strategy is conserved in the distantly related ascidian Phallusia mammillata, in spite of extreme sequence divergence in the cis-regulatory sequences involved. Our results thus highlight that the modes of gene regulatory network evolution differ with the evolutionary scale considered. Within ascidians, developmental regulatory networks are remarkably robust to genome sequence divergence. Between ascidians and vertebrates, major fate determinants, such as Otx and Nodal, can be co-opted into different networks. Comparative developmental studies in ascidians with divergent genomes will thus uncover shared ascidian strategies, and contribute to a better understanding of the diversity of developmental strategies within chordates.

  8. Tenacibaculum ascidiaceicola sp. nov., isolated from the golden sea squirt Halocynthia aurantium.

    Science.gov (United States)

    Kim, Young-Ok; Park, In-Suk; Park, Sooyeon; Nam, Bo-Hye; Park, Ji-Min; Kim, Dong-Gyun; Yoon, Jung-Hoon

    2016-03-01

    A Gram-stain-negative, non-flagellated, non-spore-forming bacterial strain motile by gliding, designated RSS1-6T, was isolated from a golden sea squirt Halocynthia aurantium and its taxonomic position was investigated by using a polyphasic approach. Strain RSS1-6T grew optimally at 30-37 °C and in the presence of 1.0-4.0 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences showed that strain RSS1-6T fell within the clade comprising species of the genus Tenacibaculum, clustering with the type strains of Tenacibaculum discolor, Tenacibaculum litoreum and Tenacibaculum gallaicum with which it exhibited 16S rRNA gene sequence similarity values of 98.5-99.5 %. Strain RSS1-6T contained MK-6 as the predominant menaquinone and iso-C15 : 0, iso-C17 : 0 3-OH and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) as the major fatty acids. The major polar lipids of strain RSS1-6T were phosphatidylethanolamine, two unidentified lipids, one unidentified aminophospholipid and one unidentified glycolipid. The DNA G+C content was 32.5 mol% and the mean DNA-DNA relatedness values with the type strains of T. discolor, T. litoreum and T. gallaicum were 17.3-25.2 %. The differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain RSS1-6T is separated from other recognized species of the genus Tenacibaculum. On the basis of the data presented, strain RSS1-6T is considered to represent a novel species of the genus Tenacibaculum, for which the name Tenacibaculum ascidiaceicola sp. nov. is proposed. The type strain is RSS1-6T ( = KCTC 42702T = NBRC 111225T). PMID:26674528

  9. An Otx/Nodal Regulatory Signature for Posterior Neural Development in Ascidians

    OpenAIRE

    Agnès Roure; Patrick Lemaire; Sébastien Darras

    2014-01-01

    In chordates, neural induction is the first step of a complex developmental process through which ectodermal cells acquire a neural identity. In ascidians, FGF-mediated neural induction occurs at the 32-cell stage in two blastomere pairs, precursors respectively of anterior and posterior neural tissue. We combined molecular embryology and cis-regulatory analysis to unveil in the ascidian Ciona intestinalis the remarkably simple proximal genetic network that controls posterior neural fate acqu...

  10. Huntingtin gene evolution in Chordata and its peculiar features in the ascidian Ciona genus

    OpenAIRE

    Cattaneo Elena; Pesole Graziano; Gissi Carmela; Tartari Marzia

    2006-01-01

    Abstract Background To gain insight into the evolutionary features of the huntingtin (htt) gene in Chordata, we have sequenced and characterized the full-length htt mRNA in the ascidian Ciona intestinalis, a basal chordate emerging as new invertebrate model organism. Moreover, taking advantage of the availability of genomic and EST sequences, the htt gene structure of a number of chordate species, including the cogeneric ascidian Ciona savignyi, and the vertebrates Xenopus and Gallus was reco...

  11. Antibacterial modified diketopiperazines from two ascidians of the genus Didemnum

    Energy Technology Data Exchange (ETDEWEB)

    Kossuga, Miriam H.; Lira, Simone P.; McHugh, Shayna; Torres, Yohandra R.; Berlinck, Roberto G.S. [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Inst. de Quimica; Lima, Bruna A.; Goncalves, Reginaldo [Universidade Estadual de Campinas, Piracicaba, SP (Brazil). Faculdade de Odontologia. Dept. de Diagnostico Oral; Veloso, Katyuscya; Ferreira, Antonio G. [Universidade Federal de Sao Carlos, SP (Brazil). Dept. de Quimica; Rocha, Rosana M. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Centro Politecnico. Setor de Ciencias Biologicas. Dept. de Zoologia

    2009-07-01

    The chemical investigation of the crude extract of an ascidian of the genus Didemnum led to the isolation of the modified diketopiperazine rodriguesines A (1) and (2) as a mixture of homologues, which could be identified by analysis of spectroscopic data including MS/MS experiments. The investigation of a second Didemnum sp. led to the isolation of N-acetyl-rodriguesine A (3) and N-acetyl-rodriguesine B (4). The absolute configuration of compounds 1 and 2 could be established by hydrolysis and Marfey's analysis and comparison with literature data reported for compound 3, previously obtained as a synthetic product. The mixture of 1 and 2 displayed moderate antibiotic activity against a clinical isolate of Streptococcus mutans and against S. mutans UA159 and Staphylococcus aureus ATCC6538. (author)

  12. Colony specificity and chemotaxis in the compound ascidian Botryllus schlosseri.

    Science.gov (United States)

    Cima, Francesca; Sabbadin, Armando; Zaniolo, Giovanna; Ballarin, Loriano

    2006-11-01

    We re-investigated the behavior of hemocytes during the non-fusion (rejection) reaction between genetically incompatible colonies of the ascidian Botryllus schlosseri. In the course of the reaction, hemocytes - mainly morula cells - crowd inside the blind ends of marginal vascular vessels (known as ampullae) of the colonial leading edge (LE) facing the foreign colony which suggests the occurrence of chemotactic attraction of circulating hemocytes towards the ampullar lumen. Then, cells migrate, through the ampullar tips, into the partially fused tunics and contribute to the formation of the necrotic spots along the contact borders which characterize the reaction. Studies on histological sections clearly indicate that, although morula cell concentration is always higher in ampullae of the LE than in those of the lateral (L) part of the colony, their frequency significantly increases in LE ampullae of rejecting colonies with respect to LE ampullae of both fusing and isolated colonies. In addition, in vitro chemotaxis experiments demonstrated that blood plasma from incompatible colonies can stimulate morula cell migration through polycarbonate filters and this passage is inhibited by antibodies raised against mammalian pro-inflammatory cytokines. The possible nature and role of molecules recognized by anti-cytokine antibodies in hemocyte migration are discussed. PMID:16962802

  13. Proteomics of ionomycin-induced ascidian sperm reaction: Released and exposed sperm proteins in the ascidian Ciona intestinalis.

    Science.gov (United States)

    Nakazawa, Shiori; Shirae-Kurabayashi, Maki; Otsuka, Kei; Sawada, Hitoshi

    2015-12-01

    Sperm proteins mediating sperm-egg interaction should be exhibited on the sperm surface, or exposed or released when sperm approach an egg. In ascidians (protochordates), sperm undergo a sperm reaction, characterized by enhanced sperm motility and mitochondrial swelling and shedding on contact with the vitelline coat (VC) or by treatment with Ca(2+) ionophore. Here, proteomic analysis was conducted on sperm exudates and sperm surface proteins using ionomycin-induced sperm reaction and cell-impermeable labeling in Ciona intestinalis type A (C. robusta). In the exudate from sperm treated with ionomycin, membrane proteins including a possible VC receptor CiUrabin were abundant, indicating the release of membranous compartments during sperm reaction. Among the surface proteins XP_009859314.1 (uncharacterized protein exhibiting homology to HrTTSP-1) was most abundant before the sperm reaction, but XP_004227079.1 (unknown Ig superfamily protein) appears to be most abundantly exposed by the sperm reaction. Moreover, proteins containing a notable set of domains, astacin-like metalloprotease domain and thrombospondin type 1 repeat(s), were found in this fraction. Possible roles in fertilization as well as localizations and behaviors of these proteins are discussed. PMID:26223815

  14. ANISEED 2015: a digital framework for the comparative developmental biology of ascidians.

    Science.gov (United States)

    Brozovic, Matija; Martin, Cyril; Dantec, Christelle; Dauga, Delphine; Mendez, Mickaël; Simion, Paul; Percher, Madeline; Laporte, Baptiste; Scornavacca, Céline; Di Gregorio, Anna; Fujiwara, Shigeki; Gineste, Mathieu; Lowe, Elijah K; Piette, Jacques; Racioppi, Claudia; Ristoratore, Filomena; Sasakura, Yasunori; Takatori, Naohito; Brown, Titus C; Delsuc, Frédéric; Douzery, Emmanuel; Gissi, Carmela; McDougall, Alex; Nishida, Hiroki; Sawada, Hitoshi; Swalla, Billie J; Yasuo, Hitoyoshi; Lemaire, Patrick

    2016-01-01

    Ascidians belong to the tunicates, the sister group of vertebrates and are recognized model organisms in the field of embryonic development, regeneration and stem cells. ANISEED is the main information system in the field of ascidian developmental biology. This article reports the development of the system since its initial publication in 2010. Over the past five years, we refactored the system from an initial custom schema to an extended version of the Chado schema and redesigned all user and back end interfaces. This new architecture was used to improve and enrich the description of Ciona intestinalis embryonic development, based on an improved genome assembly and gene model set, refined functional gene annotation, and anatomical ontologies, and a new collection of full ORF cDNAs. The genomes of nine ascidian species have been sequenced since the release of the C. intestinalis genome. In ANISEED 2015, all nine new ascidian species can be explored via dedicated genome browsers, and searched by Blast. In addition, ANISEED provides full functional gene annotation, anatomical ontologies and some gene expression data for the six species with highest quality genomes. ANISEED is publicly available at: http://www.aniseed.cnrs.fr. PMID:26420834

  15. Immunobiology of compound ascidians, with particular reference to Botryllus schlosseri: state of art

    Directory of Open Access Journals (Sweden)

    L Ballarin

    2008-05-01

    Full Text Available The phylogenetic position of invertebrate chordates closely related to vertebrates explains the increasing interest towards tunicate immunobiology. Most of the tunicates are ascidians which, like all other invertebrates, rely only on innate immunity for their defense. Compound ascidians differ from solitary species for the presence of colony specificity, i.e. the ability for intraspecific non-self recognition. The immunobiology of compound ascidians has been particularly studied in Botryllus schlosseri, which is an emerging model organism for this kind of studies. In B. schlosseri and related species, immunocytes are represented by phagocytes and cytotoxic morula cells, the former able to ingest foreign cell and particles, the latter representing the effectors of the inflammatory reaction which follows the contact between genetically incompatible colonies. Activated phagocytes release lectins with opsonic activity and are involved in the clearance of apoptotic cells during the colonial generational change. Morula cells recognize the presence of foreign molecules as well as allogeneic soluble factors diffusing from an alien colony and as a consequence they: i release cytokines in the medium which have chemotactic activity and activate phagocytes; ii degranulate and release phenoloxidase which induces necrotic cell death by oxidative stress. A better knowledge of Botryllus genome will allow a deeper insight into open problems in immunobiology of compound ascidians.

  16. Quinone and Hydroquinone Metabolites from the Ascidians of the Genus Aplidium

    OpenAIRE

    Camila Spereta Bertanha; Ana Helena Januário; Tavane Aparecida Alvarenga; Letícia Pereira Pimenta; Silva, Márcio Luis Andrade e; Wilson Roberto Cunha; Patrícia Mendonça Pauletti

    2014-01-01

    Ascidians of the genus Aplidium are recognized as an important source of chemical diversity and bioactive natural products. Among the compounds produced by this genus are non-nitrogenous metabolites, mainly prenylated quinones and hydroquinones. This review discusses the isolation, structural elucidation, and biological activities of quinones, hydroquinones, rossinones, longithorones, longithorols, floresolides, scabellones, conicaquinones, aplidinones, thiaplidiaquinones, and conithiaquinone...

  17. Modiolarca lateralis (Pteryomorphia: Mytilidae: bivalve associated to six species of ascidians from Bocas del Toro, Panama

    Directory of Open Access Journals (Sweden)

    Juan I Cañete

    2013-11-01

    Full Text Available We describe the presence of the bivalve Modiolarca lateralis (Say, 1822 in six tropical ascidians Ascidia curvata, A. sydneiensis, A. panamensis, A. interrupta, Herdmania pallida and Polycarpa spongiabilis collected at depths of 1-3 m on coral reefs, mangrove roots and dock supports in Almirante Bay, Bocas del Toro, Panama (9°18'N, 82°13'W during June-July 2011. Bivalve prevalence varied between 9-30% across species, but was mainly associated with A. panamensis, P. spongiabilis and A. interrupta. Prevalence seems to be influenced by tunic thickness rather than by the ascidian size. Bivalves varied in size (0.6-11 mm shell length, with the smallest individual found in A. sydneiensis. There were only one or two bivalves per ascidians, although a maximum of 18 was found in one A. panamensis. M. lateralis seems to behave similarly to its temperate counterparts: it has a variety of hosts, occurs mainly in the anterior region of the ascidians, and has a variable abundance per host.

  18. Pseudoroseovarius zhejiangensis gen. nov., sp. nov., a novel alpha-proteobacterium isolated from the chemical wastewater, and reclassification of Roseovarius crassostreae as Pseudoroseovarius crassostreae comb. nov., Roseovarius sediminilitoris as Pseudoroseovarius sediminilitoris comb. nov. and Roseovarius halocynthiae as Pseudoroseovarius halocynthiae comb. nov.

    Science.gov (United States)

    Sun, Cong; Pan, Jie; Zhang, Xin-Qi; Su, Yue; Wu, Min

    2015-08-01

    A Gram-stain negative, aerobic, non-motile and ovoid- to rod-shaped bacterial strain, designated JB3(T), was isolated from a wastewater sample collected from the biochemical reaction basin of Haiyan fine chemical factory in Zhejiang, China. Strain JB3(T) was found to grow optimally at pH 7.0-8.0, at 28 °C and in the presence of 1.0-2.0 % (w/v) NaCl. Chemotaxonomic analysis showed that strain JB3(T) contains ubiquinone-10 (>99 %) as the predominant respiratory quinone and C18:1 ω7c (70.9 %) as the most abundant fatty acid. The polar lipids of strain JB3(T) were identified as phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, an aminophospholipid, an unidentified aminolipid, four unidentified phospholipids and three unidentified lipids. The DNA G+C content of strain JB3(T) was determined to be 68.1 mol%. The 16S rRNA gene sequence similarities between the isolate and Roseovarius crassostreae DSM 16950(T), Roseovarius sediminilitoris KCTC 23959(T) and Roseovarius halocynthiae MA1-10(T) were found to be 97.1, 96.8 and 96.2 %, respectively. Morevoer, the similarity between strain JB3(T) and the type strain of the genus Roseovarius (Roseovarius tolerans DSM 11457(T)) was found to be 93.8 %. The phylogenetic trees reconstructed with all three treeing methods showed that strain JB3(T) constituted a different taxon, which was separate from other taxa with validly published names, and formed a cluster with R. crassostreae DSM 16950(T), R. sediminilitoris KCTC 23959(T) and R. halocynthiae MA1-10(T). These three species were not placed within the phylogenetic cluster formed by R. tolerans DSM 11457(T). Differential phenotypic properties, together with the phylogenetic distinctiveness, demonstrated that strain JB3(T) is clearly distinct from species of the genus Roseovarius. On the basis of these features, we propose strain JB3(T) represents a novel species of a novel genus with the name Pseudoroseovarius zhejiangensis gen. nov., sp

  19. When shape matters: strategies of different Antarctic ascidians morphotypes to deal with sedimentation.

    Science.gov (United States)

    Torre, Luciana; Abele, Doris; Lagger, Cristian; Momo, Fernando; Sahade, Ricardo

    2014-08-01

    Climate change leads to increased melting of tidewater glaciers in the Western Antarctic Peninsula region and sediment bearing glacial melt waters negatively affects filter feeding species as solitary ascidians. In previous work the erect-forms Molgula pedunculata and Cnemidocarpa verrucosa (Order Stolidobranchiata) appeared more sensitive than the flat form Ascidia challengeri (Order Phlebobranchiata). Sedimentation exposure is expected to induce up-regulation of anaerobic metabolism by obstructing the organs of gas exchange (environmental hypoxia) or causes enhanced squirting activity (functional hypoxia). In this study we evaluated the possible relationship between ascidian morphotype and their physiological response to sedimentation. Together with some behavioural observations, we analysed the response of anaerobic metabolic parameters (lactate formation and glycogen consumption) in different tissues of three Antarctic ascidians, exposed to high sediment concentrations (200 mgL(-1)). The results were compared to experimental hypoxia (10% pO2) and exercise (induced muscular contraction) effects, in order to discriminate the effect of sediment on each species and morpho-type (erect vs. flat forms). Our results suggest that the styled (erect) C. verrucosa increases muscular squirting activity in order to expulse excessive material, while the flat-form A. challengeri reacts more passively by down-regulating its aerobic metabolism under sediment exposure. Contrary, the erect ascidian M. pedunculata did not show any measurable response to the treatments, indicating that filtration and ingestion activities were not reduced or altered even under high sedimentation (low energetic material) which could be disadvantageous on the long-term and could explain why M. pedunculata densities decline in the study area. PMID:24986145

  20. Development of translationally active mRNA for larval muscle acetylcholinesterase during ascidian embryogenesis.

    OpenAIRE

    Meedel, T H; Whittaker, J R

    1983-01-01

    Relative quantities of translationally active acetylcholinesterase (acetylcholine acetylhydrolase, EC 3.1.1.7) mRNA present at various developmental stages were compared in embryos of the ascidian Ciona intestinalis. Purified RNA was tested for its translational capacity by microinjection into Xenopus laevis oocytes; the acetylcholinesterase produced was immunoprecipitated with antibody to Ciona acetylcholinesterase and enzyme activity was assayed radiometrically. With this protocol, enzyme s...

  1. Quinone and Hydroquinone Metabolites from the Ascidians of the Genus Aplidium

    Directory of Open Access Journals (Sweden)

    Camila Spereta Bertanha

    2014-06-01

    Full Text Available Ascidians of the genus Aplidium are recognized as an important source of chemical diversity and bioactive natural products. Among the compounds produced by this genus are non-nitrogenous metabolites, mainly prenylated quinones and hydroquinones. This review discusses the isolation, structural elucidation, and biological activities of quinones, hydroquinones, rossinones, longithorones, longithorols, floresolides, scabellones, conicaquinones, aplidinones, thiaplidiaquinones, and conithiaquinones. A compilation of the 13C-NMR spectral data of these compounds is also presented.

  2. Quinone and hydroquinone metabolites from the ascidians of the genus Aplidium.

    Science.gov (United States)

    Bertanha, Camila Spereta; Januário, Ana Helena; Alvarenga, Tavane Aparecida; Pimenta, Letícia Pereira; Silva, Márcio Luis Andrade E; Cunha, Wilson Roberto; Pauletti, Patrícia Mendonça

    2014-06-01

    Ascidians of the genus Aplidium are recognized as an important source of chemical diversity and bioactive natural products. Among the compounds produced by this genus are non-nitrogenous metabolites, mainly prenylated quinones and hydroquinones. This review discusses the isolation, structural elucidation, and biological activities of quinones, hydroquinones, rossinones, longithorones, longithorols, floresolides, scabellones, conicaquinones, aplidinones, thiaplidiaquinones, and conithiaquinones. A compilation of the 13C-NMR spectral data of these compounds is also presented. PMID:24927227

  3. Distribution and Localised Effects of the Invasive Ascidian Didemnum perlucidum (Monniot 1983) in an Urban Estuary.

    Science.gov (United States)

    Simpson, Tiffany Schenk; Wernberg, Thomas; McDonald, Justin I

    2016-01-01

    Didemnid ascidians are notorious marine invaders, fouling infrastructure in many ecosystems globally. However, there have been few reports of direct interactions with native species in their natural environment. The invasive colonial ascidian Didemnum perlucidum was discovered in the Swan River estuary (Western Australia) growing on the native seagrass Halophila ovalis. Given the known effects of other related Didemnum species it was expected that D. perlucidum could adversely affect the seagrass, with possible flow on effects to the rest of the ecosystem. This study aimed to document the distribution and abundance of D. perlucidum in the estuary, and to determine whether this species had a negative impact on H. ovalis or associated flora and fauna. D. perlucidum was largely present near areas of infrastructure, particularly mooring buoys, suggesting these were the source of D. perlucidum recruits on the seagrasses. It showed a clear seasonal pattern in abundance, with highly variable cover and colony size. D. perlucidum had a measurable effect on H. ovalis, with colonies enveloping all plant tissue, likely restricting the photosynthetic ability of individual leaves and total plant biomass. There were also significantly less seagrass-associated mud snails (Batillaria australis) where D. perlucidum cover was high. These results demonstrate the ability of invasive ascidians to colonise and affect native seagrasses and associated biota. Seagrasses are pivotal to the ecological function of many urban estuaries world-wide. Biodiversity in these systems is already vulnerable to multiple stressors from human activities but the potential stress of fouling ascidians may pose an additional and increasing threat in the future. PMID:27144600

  4. Transcript Mapping and Genome Annotation of Ascidian mtDNA Using EST Data

    OpenAIRE

    Gissi, Carmela; Pesole, Graziano

    2003-01-01

    Mitochondrial transcripts of two ascidian species were reconstructed through sequence assembly of publicly available ESTs resembling mitochondrial DNA sequences (mt-ESTs). This strategy allowed us to analyze processing and mapping of the mitochondrial transcripts and to investigate the gene organization of a previously uncharacterized mitochondrial genome (mtDNA). This new strategy would greatly facilitate the sequencing and annotation of mtDNAs. In Ciona intestinalis, the assembled mt-...

  5. Ultrastructures and Classification of Circulating Hemocytes in 9 Botryllid Ascidians (Chordata: Ascidiacea)

    OpenAIRE

    Hirose, Euichi; Shirae, Maki; Saito, Yasunori

    2003-01-01

    Ultrastructures of circulating hemocytes were studied in 9 botryllid ascidians. The hemocytes are classified into five types: hemoblasts, phagocytes, granulocytes, morula cells, and pigment cells. These five types are always found in the 9 species. They should represent the major hemocyte types of the circulating cells in the blood. Hemoblasts are small hemocytes having a high nucleus/cytoplasm ratio. There are few granular or vacuolar inclusions in the cytoplasm. Phagocytes have phagocytic a...

  6. Solitary ascidians embryos (Chordata, Tunicata) as model organisms for testing coastal pollutant toxicity

    OpenAIRE

    G Zega; R. Pennati; S Candiani; M Pestarino; Bernardi, F

    2009-01-01

    Marine coastal communities are daily exposed to several chemical compounds commonly used in agriculture and industrial activities. Therefore, toxicological studies evaluating the effects of these compounds on marine organisms are of primary importance for marine environment preservation. Different model organisms are used to perform toxicity tests with potential pollutants, under laboratory conditions. In last decades, solitary ascidians have been selected as valuable model organisms to run b...

  7. THALIACEANS, THE NEGLECTED PELAGIC RELATIVES OF ASCIDIANS: A DEVELOPMENTAL AND EVOLUTIONARY ENIGMA.

    Science.gov (United States)

    Piette, Jacques; Lemaire, Patrick

    2015-06-01

    Most developmental biologists equate tunicates to the sessile ascidians, including Ciona intestinalis, and the pelagic appendicularians, in particular Oikopleura dioica. However, there exists a third group of tunicates with a pelagic lifestyle, the thaliaceans, which include salps, pyrosomes, and doliolids. Although thaliaceans have raised the curiosity offamous zoologists since the 18th century, the difficulty of observing and experimentally manipulating them has led to many controversies and speculations about their life cycles and developmental strategies, the phylogenetic relationship within the group and with other tunicates, and the drivers of speciation in these widely distributed animals living in a seemingly uniform environment. Here, we take a historical perspective to summarize 250 years of work on this intriguing group of animals, and explore how modern genomics and imaging approaches are starting to solve fascinating evolutionary and developmental riddles. Recent molecular analyses support previous morphological evidence that ascidians are not monophyletic and that thaliaceans evolved from a sessile ascidian-like ancestor. In parallel, preliminary live-imaging and gene-expression data offer exciting entry points to understand how the adoption of a pelagic lifestyle led to drastic modifications in the morphology, embryology, and life cycle of these tunicates, compared to their sessile ancestor. PMID:26285352

  8. Spermiotoxicity of nickel nanoparticles in the marine invertebrate Ciona intestinalis (ascidians).

    Science.gov (United States)

    Gallo, Alessandra; Boni, Raffaele; Buttino, Isabella; Tosti, Elisabetta

    2016-10-01

    Nickel nanoparticles (Ni NPs) are increasingly used in modern industries as catalysts, sensors, and in electronic applications. Due to this large use, their inputs into marine environment have significantly increased; however, the potential ecotoxicological effects in marine environment have so far received little attention. In particular, little is known on the impact of NPs on gamete quality of marine organisms and on the consequences on fertility potential. The present study examines, for the first time, the impact of Ni NPs exposure on sperm quality of the marine invertebrate Ciona intestinalis (ascidian). Several parameters related with sperm status such as plasma membrane lipid peroxidation, mitochondrial membrane potential (MMP), intracellular pH, DNA integrity, and fertilizing ability were assessed as toxicity end points after exposure to different Ni NPs concentrations. Ni NPs generate oxidative stress that in turn induces lipid peroxidation and DNA fragmentation, and alters MMP and sperm morphology. Furthermore, sperm exposure to Ni NPs affects their fertilizing ability and causes developmental anomalies in the offspring. All together, these results reveal a spermiotoxicity of Ni NPs in ascidians suggesting that the application of these NPs should be carefully assessed as to their potential toxic effects on the health of marine organisms that, in turn, may influence the ecological system. This study shows that ascidian sperm represent a suitable and sensitive tool for the investigation of the toxicity of NPs entered into marine environment, for defining the mechanisms of toxic action and for the environmental monitoring purpose. PMID:27080039

  9. Solitary ascidians embryos (Chordata, Tunicata as model organisms for testing coastal pollutant toxicity

    Directory of Open Access Journals (Sweden)

    G Zega

    2009-03-01

    Full Text Available Marine coastal communities are daily exposed to several chemical compounds commonly used in agriculture and industrial activities. Therefore, toxicological studies evaluating the effects of these compounds on marine organisms are of primary importance for marine environment preservation. Different model organisms are used to perform toxicity tests with potential pollutants, under laboratory conditions. In last decades, solitary ascidians have been selected as valuable model organisms to run bioassays with embryos and larvae. In fact, by in vitro fertilization, it is easy to obtain thousands of embryos, rapidly developing and therefore allowing a fast screen of pollutant toxicity.The aim of this review was to summarize results from toxicity tests, run with heavy metals, organo-metal and organic compounds, on solitary ascidian development and settlement to evidence that these animals offer several advantages as models to perform these kind of studies. First of all, they have a sensitiveness directly comparable to that of other marine model organisms. Moreover, the effects of toxicants on exposed embryos and larvae could be studied using different approaches, from ultrastructure to genetic analysis. Finally, since ascidians are chordates morphological and gene expression analyses could provide data for comparative studies with vertebrates.

  10. Nitric oxide acts as a positive regulator to induce metamorphosis of the ascidian Herdmania momus.

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    Nobuo Ueda

    Full Text Available Marine invertebrates commonly have a biphasic life cycle in which the metamorphic transition from a pelagic larva to a benthic post-larva is mediated by the nitric oxide signalling pathway. Nitric oxide (NO is synthesised by nitric oxide synthase (NOS, which is a client protein of the molecular chaperon heat shock protein 90 (HSP90. It is notable, then, that both NO and HSP90 have been implicated in regulating metamorphosis in marine invertebrates as diverse as urochordates, echinoderms, molluscs, annelids, and crustaceans. Specifically, the suppression of NOS activity by the application of either NOS- or HSP90-inhibiting pharmacological agents has been shown consistently to induce the initiation of metamorphosis, leading to the hypothesis that a negative regulatory role of NO is widely conserved in biphasic life cycles. Further, the induction of metamorphosis by heat-shock has been demonstrated for multiple species. Here, we investigate the regulatory role of NO in induction of metamorphosis of the solitary tropical ascidian, Herdmania momus. By coupling pharmacological treatments with analysis of HmNOS and HmHSP90 gene expression, we present compelling evidence of a positive regulatory role for NO in metamorphosis of this species, in contrast to all existing ascidian data that supports the hypothesis of NO as a conserved negative regulator of metamorphosis. The exposure of competent H. momus larvae to a NOS inhibitor or an NO donor results in an up-regulation of NOS and HSP90 genes. Heat shock of competent larvae induces metamorphosis in a temperature dependent manner, up to a thermal tolerance that approaches 35°C. Both larval/post-larval survival and the appearance of abnormal morphologies in H. momus post-larvae reflect the magnitude of up-regulation of the HSP90 gene in response to heat-shock. The demonstrated role of NO as a positive metamorphic regulator in H. momus suggests the existence of inter-specific adaptations of NO regulation

  11. Huntingtin gene evolution in Chordata and its peculiar features in the ascidian Ciona genus

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    Cattaneo Elena

    2006-11-01

    Full Text Available Abstract Background To gain insight into the evolutionary features of the huntingtin (htt gene in Chordata, we have sequenced and characterized the full-length htt mRNA in the ascidian Ciona intestinalis, a basal chordate emerging as new invertebrate model organism. Moreover, taking advantage of the availability of genomic and EST sequences, the htt gene structure of a number of chordate species, including the cogeneric ascidian Ciona savignyi, and the vertebrates Xenopus and Gallus was reconstructed. Results The C. intestinalis htt transcript exhibits some peculiar features, such as spliced leader trans-splicing in the 98 nt-long 5' untranslated region (UTR, an alternative splicing in the coding region, eight alternative polyadenylation sites, and no similarities of both 5' and 3'UTRs compared to homologs of the cogeneric C. savignyi. The predicted protein is 2946 amino acids long, shorter than its vertebrate homologs, and lacks the polyQ and the polyP stretches found in the the N-terminal regions of mammalian homologs. The exon-intron organization of the htt gene is almost identical among vertebrates, and significantly conserved between Ciona and vertebrates, allowing us to hypothesize an ancestral chordate gene consisting of at least 40 coding exons. Conclusion During chordate diversification, events of gain/loss, sliding, phase changes, and expansion of introns occurred in both vertebrate and ascidian lineages predominantly in the 5'-half of the htt gene, where there is also evidence of lineage-specific evolutionary dynamics in vertebrates. On the contrary, the 3'-half of the gene is highly conserved in all chordates at the level of both gene structure and protein sequence. Between the two Ciona species, a fast evolutionary rate and/or an early divergence time is suggested by the absence of significant similarity between UTRs, protein divergence comparable to that observed between mammals and fishes, and different distribution of repetitive

  12. Aliiroseovarius pelagivivens gen. nov., sp. nov., isolated from seawater, and reclassification of three species of the genus Roseovarius as Aliiroseovarius crassostreae comb. nov., Aliiroseovarius halocynthiae comb. nov. and Aliiroseovarius sediminilitoris comb. nov.

    Science.gov (United States)

    Park, Sooyeon; Park, Ji-Min; Kang, Chul-Hyung; Yoon, Jung-Hoon

    2015-08-01

    A Gram-stain-negative, non-motile, aerobic and ovoid or rod-shaped bacterium, designated GYSW-22T, was isolated from seawater off Geoje Island in the South Sea, South Korea. Strain GYSW-22T grew optimally at 25 °C, at pH 7.0-8.0 and in the presence of 1.0-2.0% (w/v) NaCl. Neighbour-joining, maximum-likelihood and maximum-parsimony phylogenetic trees based on 16S rRNA gene sequences showed that strain GYSW-22T and the type strains of Roseovarius crassostreae, Roseovarius halocynthiae and Roseovarius sediminilitoris form a coherent cluster, independent of phylogenetic lineages or clusters comprising the type strains of other species of the genus Roseovarius. Strain GYSW-22T exhibited 16S rRNA gene sequence similarities of 97.2, 96.6 and 96.3% to R. halocynthiae MA1-10T, R. crassostreae CV919-312T and R. sediminilitoris M-M10T, respectively, and of 92.6-94.7% to the type strains of other species of the genus Roseovarius. Strain GYSW-22T contained Q-10 as the predominant ubiquinone and C18 : 1ω7c as the major fatty acid. The major polar lipids were phosphatidylcholine, phosphatidylglycerol, one unidentified aminolipid and one unidentified lipid. The DNA G+C content of strain GYSW-22T was 59.0 mol% and its mean DNA-DNA relatedness value with R. halocynthiae MA1-10T was 15 %. On the basis of the data presented, we propose strain GYSW-22T represents a novel species of a new genus, Aliiroseovarius pelagivivens gen. nov., sp. nov. The type strain of the type species is GYSW-22T ( = KCTC 42459T = CECT 8811T). In this study, it is also proposed that Roseovarius crassostreae, Roseovarius halocynthiae and Roseovarius sediminilitoris be reclassified into the new genus as Aliiroseovarius crassostreae comb. nov. (type strain CV919-312T = ATCC BAA-1102T = DSM 16950T), Aliiroseovarius halocynthiae comb. nov. (type strain MA1-10T = KCTC 23462T = CCUG 60745T) and Aliiroseovarius sediminilitoris comb. nov. (type strain M-M10T = KCTC 23959T

  13. DNA barcoding of two solitary ascidians, Herdmania momus Savigny, 1816 and Microcosmus squamiger Michaelsen, 1927 from Thoothukudi coast, India.

    Science.gov (United States)

    Jaffar Ali, H Abdul; Ahmed, N Shabeer

    2016-07-01

    Morphology-based taxonomical studies of ascidians in India are meagre due to lack of ascidian taxonomist and limitations inherent in conventional system-based identification. The use of short fragment of mitochondrial DNA sequence is proving highly useful in identifying species in a situation where, the traditional morphology-based identification is difficult. In the present study, two adult solitary ascidians collected from the Thoothukudi coast were morphologically identified as Herdmania momus Savigny, 1816 and Microcosmus squamiger Michaelsen, 1927. The genomic DNA of these ascidians was isolated, COI gene was amplified, sequenced and submitted to the GenBank under the accession numbers KM058116, KM411616 and KJ944390. Homology search result using BLAST showed that H. momus showed 100% matched with other H. momus, while M. squamiger showed similarity with Pyura herdmani, a member of the same family Pyuridae. The phylogenetic and genetic distance was maximum in interspecies than in intraspecies. These COI sequences will allow the identification of the species through DNA barcoding technique. Here, we report for the first time the COI gene of H. momus, Savigny 1816 from the Indian coast. PMID:26122341

  14. Significant reduction in allergenicity of ovalbumin from chicken egg white following treatment with ascidian viscera N-acetylglucosaminidase.

    Science.gov (United States)

    Hwang, Hye Seong; Park, Heajin; Kim, Jihye; Choi, Jai Yeon; Lee, Young Kwang; Park, Ho-Young; Choi, Hee-Don; Kim, Ha Hyung

    2016-06-17

    Ovalbumin (OA) is the most abundant ingredient of chicken egg-white allergenic proteins. In the present study we investigated the possibility of reducing OA allergenicity by treatment with a natural protein exhibiting N-acetylglucosaminidase (NA) activity. Ascidian is cultivated as a food resource in northeast Asia. The ascidian viscera NA (AVNA) with almost no other exoglycosidases or proteolytic enzymes was isolated by applying size-exclusion chromatography to a protein precipitate of ascidian viscera. Intact OA was mixed with AVNA containing 0.2, 1.0, and 5.0 Units of NA. Anion-exchange chromatography was then used to isolate OA from AVNA-treated OA. The electrophoretic patterns and N-glycans of each isolated OA from AVNA-treated OA (iOA) were analyzed, and the terminal N-acetylglucosamines of iOA were selectively cleaved with no other degradation occurring. A competitive indirect enzyme-linked immunosorbent assay using rabbit anti-OA sera was performed to investigate the allergenicity of iOA, which was found to be significantly reduced depending on the increased NA activity compared to that of intact OA. These results indicate that OA allergenicity was reduced using a simple and mild treatment process with AVNA, and suggest that ascidian NA is an efficient natural protein for reducing the allergenicity of OA without requiring the use of harsh physical treatments or chemical conjugation. PMID:27178210

  15. Ultrastructural comparative analysis on the adhesive papillae of the swimming larvae of three ascidian species

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    G Dolcemascolo

    2009-03-01

    Full Text Available This paper presents a preliminary report on the papillae of the swimming larvae of three ascidian species: Ascidia malaca, Phallusia mammillata and Ciona intestinalis. The investigations, carried out at ultrastructural level and at confocal laser microscope, have evidenced, in the adhesive papillae of the three studied species, three different cell-types: axial columnar cells, collocytes, sensory cells respectively. The adhesive papillae of A. malaca and P. mammillata show central axial columnar cells with long microvilli emerging from the apical edge and extending throughout the hyaline cap. Collocytes are elongated secreting cells, lying in middle-lateral side. Sensory cells have a cilium at the apical side and an axon proceeding from the basal side. The adhesive papillae of C. intestinalis present some differences in the ultrastructure of the axial columnar cells, which bear a big digitiform protrusion, extending throughout the hyaline cap and a lot of microtubules along the cell axis. The investigations, carried out at confocal microscopy, have evidentiated a clear fluorescence in the papillae of the three studied species and a network of nervous fibers projecting from the papillar base up to cerebral vesicle of the cephalenteron. The characteristic of simple and coniforme type and the adhesive and sensorial functions of adhesive papillae of three ascidian species examined are confirmed.

  16. Inverse correlation of population similarity and introduction date for invasive ascidians.

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    Nathan Silva

    Full Text Available The genomes of many marine invertebrates, including the purple sea urchin and the solitary ascidians Ciona intestinalis and Ciona savignyi, show exceptionally high levels of heterozygosity, implying that these populations are highly polymorphic. Analysis of the C. savignyi genome found little evidence to support an elevated mutation rate, but rather points to a large population size contributing to the polymorphism level. In the present study, the relative genetic polymorphism levels in sampled populations of ten different ascidian species were determined using a similarity index generated by AFLP analysis. The goal was to determine the range of polymorphism within the populations of different species, and to uncover factors that may contribute to the high level of polymorphism. We observe that, surprisingly, the levels of polymorphism within these species show a negative correlation with the reported age of invasive populations, and that closely related species show substantially different levels of genetic polymorphism. These findings show exceptions to the assumptions that invasive species start with a low level of genetic polymorphism that increases over time and that closely related species have similar levels of genetic polymorphism.

  17. Two New Tryptamine Derivatives, Leptoclinidamide and (--Leptoclinidamine B, from an Indonesian Ascidian Leptoclinides dubius

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    Michio Namikoshi

    2012-02-01

    Full Text Available Two new tryptamine-derived alkaloids, named as leptoclinidamide (1 and (--leptoclinidamine B (2, were isolated from an Indonesian ascidian Leptoclinides dubius together with C2-α-D-mannosylpyranosyl-L-tryptophan (3. The structure of 1 was assigned on the basis of spectroscopic data for 1 and its N-acetyl derivative (4. Compound 1 was an amide of tryptamine with two β-alanine units. Although the planar structure of 2 is identical to that of the known compound (+-leptoclinidamine B (5, compound 2 was determined to be the enantiomer of 5 based on amino acid analysis using HPLC methods. Compounds 1 to 4 were evaluated for cytotoxicity against two human cancer cell lines, HCT-15 (colon and Jurkat (T-cell lymphoma cells, but none of the compounds showed activity.

  18. Distribution and invasiveness of a colonial ascidian, Didemnum psammathodes, along the southern Indian coastal water

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    H. Abdul Jaffar

    2016-07-01

    Full Text Available Ascidians are well known worldwide for their rapid invasions and also for the presence of potential biomedical molecules. Members of the family Didemnidae are widely distributed in tropical waters and they are reported to be among the families possessing rich bioactive compounds. Didemnum psammathodes has a cosmopolitan distribution in tropical waters. The growing evidence of multifarious potential and ever increasing invasion of this species accentuated the need for additional research into its diversity and distribution for sustainable utilization and conservation. The present study was intended to focus on distribution and invasiveness of colonial ascidian, D. psammathodes, along the southern Indian peninsular waters. The present data are based on our own observations made during 2012–2014 period and also on the published and unpublished records of the last 20 years. Out of 45 stations surveyed, D. psammathodes was encountered at a maximum of 41 stations and was found to be more abundant in Hare Island (n = 42, North Break Water (n = 38 and Vizhinjam bay (n = 32. This species was absent at four different stations. Catch per unit effort was higher (19.6 in Hare Island followed by NBW (16.0 and Vizhinjam bay (6.8. The highest number of colonies (136 was observed in calcareous stones, followed by embedded rocks (54 and molluscan shells (33. Hydrographical parameters showed no significant differences between the stations (p < 0.005. It is concluded that D. psammathodes has the potential to invade most of the stations and its distribution was not influenced by hydrographical parameters rather than substrates.

  19. Polarization of PI3K Activity Initiated by Ooplasmic Segregation Guides Nuclear Migration in the Mesendoderm.

    Science.gov (United States)

    Takatori, Naohito; Oonuma, Kouhei; Nishida, Hiroki; Saiga, Hidetoshi

    2015-11-01

    Asymmetric localization of RNA is a widely observed mechanism of cell polarization. Using embryos of the ascidian, Halocynthia roretzi, we previously showed that mesoderm and endoderm fates are separated by localization of mRNA encoding a transcription factor, Not, to the future mesoderm-side cytoplasm of the mesendoderm cell through asymmetric positioning of the nucleus. Here, we investigated the mechanism that defines the direction of the nuclear migration. We show that localization of PtdIns(3,4,5)P3 to the future mesoderm region determines the direction of nuclear migration. Localization of PtdIns(3,4,5)P3 was dependent on the localization of PI3Kα to the future mesoderm region. PI3Kα was first localized at the 1-cell stage by the ooplasmic movement. Activity of localized PI3Kα at the 4-cell stage was required for the localization of PI3Kα up to the nuclear migration. Our results provide the scaffold for understanding the chain of causality leading to the separation of germ layer fates. PMID:26555053

  20. Evaluation of antibacterial activity of crude extracts of ascidian Didemnum psammathodes Sluiter, 1895 against isolated human and fish pathogens

    Institute of Scientific and Technical Information of China (English)

    N Sri Kumaran; S Bragadeeswaran; VK Meenakshi

    2011-01-01

    Objective: To evaluate the antimicrobial activities of ascidian Didemnum psammathodes (D. psammathodes) against human and fish pathogenic organisms. Methods: In this study antimicrobial activities were carried out by standard disc diffusion method. In this experiment 40 human, fish bacterial and fungal pathogens were isolated and assayed against 7 different solvents such as methanol, acetone, ethanol, n-butanol, chloroform, ethyl acetate and dichloromethane. Each solvent were assayed at different concentrations of 25, 50, 75, 100 mg/mL. Results: From this experiment solvent having higher concentrations showed high inhibition activity and the fungi are showed more resistant than the bacterial strains used. Conclusions: These results indicate that the ascidian D. psammathodes is found to have remarkable antimicrobial activities against isolated microbes. Further studies will fulfill for purification and structural elucidation of antimicrobial drugs.

  1. Microenvironmental Ecology of the Chlorophyll b-containing Symbiotic Cyanobacterium Prochloron in the Didemnid Ascidian Lissoclinum patella

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    Michael eKühl

    2012-11-01

    Full Text Available The discovery of the cyanobacterium Prochloron was the first finding of a bacterial oxyphototroph with chlorophyll (Chl b, in addition to Chl a. It was first described as Prochloron didemni but a number of clades have since been described. Prochloron is a conspicuously large (7-25 µm unicellular cyanobacterium living in a symbiotic relationship, primarily with (sub- tropical didemnid ascidians; it has resisted numerous cultivation attempts and appears truly obligatory symbiotic. Recently, a Prochloron draft genome was published, revealing no lack of metabolic genes that could explain the apparent inability to reproduce and sustain photosynthesis in a free-living stage. Possibly, the unsuccessful cultivation is partly due to a lack of knowledge about the microenvironmental conditions and ecophysiology of Prochloron in its natural habitat. We used microsensors, variable chlorophyll fluorescence imaging and imaging of O2 and pH to obtain a detailed insight to the microenvironmental ecology and photobiology of Prochloron in hospite in the didemnid ascidian Lissoclinum patella. The microenvironment within ascidians is characterized by steep gradients of light and chemical parameters that change rapidly with varying irradiances. The interior zone of the ascidians harboring Prochloron thus became anoxic and acidic within a few min of darkness, while the same zone exhibited O2 super-saturation and strongly alkaline pH after a few min of illumination. Photosynthesis showed lack of photoinhibition even at high irradiances equivalent to full sunlight, and photosynthesis recovered rapidly after periods of anoxia. We discuss these new insights on the ecological niche of Prochloron and possible interactions with its host and other microbes in light of its recently published genome and a recent study of the overall microbial diversity and metagenome of L. patella.

  2. Studies on the seasonal variations in the proximate composition of ascidians from the Palk Bay,Southeast coast of India

    Institute of Scientific and Technical Information of China (English)

    Ananthan; G; Karthikeyan; MM; Selva; Prabhu; A; Raghunathan; C

    2012-01-01

    Objective:To investigate the seasonal fluctuations of the proximate composition of the ascidians muscle.Methods:The moisture content was estimated by drying 1 g of fresh tissue at a constant temperature at 105(?)for 24 h.The loss of weight was taken as moisture content.The total protein was estimated using the Biuret method.The total carbohydrate in dried sample was estimated spectrophotometrically following the phenol-sulphuric acid method.The lipid in the dried sample tissue was gravimetrically estimated following the chloroform-methanol mixture method.Ash content was determined gravimetrically by incinerating 1 g dried sample in muffle furnace at about 550℃for 6 h and results are expressed in percentage.Results:It was found very difficult to compare the monthly variations,as all the ten species,exhibited wide fluctuations in their proximate compositions.For the sake of convenience,average seasonal values were calculated by summing the monthly values.Conclusions:The proximate composition of the 10 commonly available ascidians showed high nutritive value and hence these groups especially solitary ascidians can be recommended for human consumption in terms of pickles,soup,curry and others after ensuring the safety of consumers.

  3. Ordered expression pattern of Hox and ParaHox genes along the alimentary canal in the ascidian juvenile.

    Science.gov (United States)

    Nakayama, Satoshi; Satou, Kunihiro; Orito, Wataru; Ogasawara, Michio

    2016-07-01

    The Hox and ParaHox genes of bilateria share a similar expression pattern along the body axis and are known to be associated with anterior-posterior patterning. In vertebrates, the Hox genes are also expressed in presomitic mesoderm and gut endoderm and the ParaHox genes show a restricted expression pattern in the gut-related derivatives. Regional expression patterns in the embryonic central nervous system of the basal chordates amphioxus and ascidian have been reported; however, little is known about their endodermal expression in the alimentary canal. We focus on the Hox and ParaHox genes in the ascidian Ciona intestinalis and investigate the gene expression patterns in the juvenile, which shows morphological regionality in the alimentary canal. Gene expression analyses by using whole-mount in situ hybridization reveal that all Hox genes have a regional expression pattern along the alimentary canal. Expression of Hox1 to Hox4 is restricted to the posterior region of pharyngeal derivatives. Hox5 to Hox13 show an ordered expression pattern correlated with each Hox gene number along the postpharyngeal digestive tract. This expression pattern along the anterior-posterior axis has also been observed in Ciona ParaHox genes. Our observations suggest that ascidian Hox and ParaHox clusters are dispersed; however, the ordered expression patterns along the alimentary canal appear to be conserved among chordates. PMID:26837224

  4. Studies on the seasonal variations in the proximate composition of ascidians from the Palk Bay, Southeast coast of India

    Institute of Scientific and Technical Information of China (English)

    Ananthan G; Karthikeyan MM; Selva Prabhu A; Raghunathan C

    2012-01-01

    To investigate the seasonal fluctuations of the proximate composition of the ascidians muscle. Methods: The moisture content was estimated by drying 1 g of fresh tissue at a constant temperature at 105 ℃ for 24 h.The loss of weight was taken as moisture content. The total protein was estimated using the Biuret method. The total carbohydrate in dried sample was estimated spectrophotometrically following the phenol- sulphuric acid method. The lipid in the dried sample tissue was gravimetrically estimated following the chloroform-methanol mixture method. Ash content was determined gravimetrically by incinerating 1 g dried sample in muffle furnace at about 550 ℃ for 6 h and results are expressed in percentage. Results: It was found very difficult to compare the monthly variations, as all the ten species, exhibited wide fluctuations in their proximate compositions. For the sake of convenience, average seasonal values were calculated by summing the monthly values. Conclusions: The proximate composition of the 10 commonly available ascidians showed high nutritive value and hence these groups especially solitary ascidians can be recommended for human consumption in terms of pickles, soup, curry and others after ensuring the safety of consumers.

  5. Dermatan sulfate in tunicate phylogeny: Order-specific sulfation pattern and the effect of [→4IdoA(2-Sulfateβ-1→3GalNAc(4-Sulfateβ-1→] motifs in dermatan sulfate on heparin cofactor II activity

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    Sugahara Kazuyuki

    2011-05-01

    Full Text Available Abstract Background Previously, we have reported the presence of highly sulfated dermatans in solitary ascidians from the orders Phlebobranchia (Phallusia nigra and Stolidobranchia (Halocynthia pyriformis and Styela plicata. Despite the identical disaccharide backbone, consisting of [→4IdoA(2Sβ-1→3GalNAcβ-1→], those polymers differ in the position of sulfation on the N-Acetyl galactosamine, which can occur at carbon 4 or 6. We have shown that position rather than degree of sulfation is important for heparin cofactor II activity. As a consequence, 2,4- and 2,6-sulfated dermatans have high and low heparin cofactor II activities, respectively. In the present study we extended the disaccharide analysis of ascidian dermatan sulfates to additional species of the orders Stolidobranchia (Herdmania pallida, Halocynthia roretzi and Phlebobranchia (Ciona intestinalis, aiming to investigate how sulfation evolved within Tunicata. In addition, we analysed how heparin cofactor II activity responds to dermatan sulfates containing different proportions of 2,6- or 2,4-disulfated units. Results Disaccharide analyses indicated a high content of disulfated disaccharide units in the dermatan sulfates from both orders. However, the degree of sulfation decreased from Stolidobranchia to Phlebobranchia. While 76% of the disaccharide units in dermatan sulfates from stolidobranch ascidians are disulfated, 53% of disulfated disaccharides are found in dermatan sulfates from phlebobranch ascidians. Besides this notable difference in the sulfation degree, dermatan sulfates from phlebobranch ascidians contain mainly 2,6-sulfated disaccharides whereas dermatan sulfate from the stolidobranch ascidians contain mostly 2,4-sulfated disaccharides, suggesting that the biosynthesis of dermatan sulfates might be differently regulated during tunicates evolution. Changes in the position of sulfation on N-acetylgalactosamine in the disaccharide [→4IdoA(2-Sulfateβ-1→3GalNAcβ-1

  6. Ecological observations on the colonial ascidian Didemnum sp. in a New England tide pool habitat

    Science.gov (United States)

    Valentine, P.C.; Carman, M.R.; Blackwood, D.S.; Heffron, E.J.

    2007-01-01

    The colonial ascidian Didemnum sp. has colonized northwestern Atlantic coastal habitats from southern Long Island, New York, to Eastport, Maine. It is also present in offshore habitats of the Georges Bank fishing grounds. It threatens to alter fisheries habitats and shellfish aquacultures. Observations in a tide pool at Sandwich, MA from December 2003 to February 2006 show that Didemnum sp. tolerates water temperatures ranging from ≤ 1 to > 24 °C, with daily changes of up to 11 °C. It attaches to pebbles, cobbles, and boulders, and it overgrows other tunicates, seaweeds, sponges, and bivalves. From May to mid July, colonies appear as small patches on the bottoms of rocks. Colonies grow rapidly from July to September, with some growth into December, and they range in color from pink to pale yellow to pale orange. Colony health declines from October through April, presumably in response to changes in water temperatures, and this degenerative process is manifested by color changes, by the appearance of small dark brown spots that represent clumps of fecal pellets in the colony, by scavenging by periwinkles, and by a peeling-away of colonies from the sides of cobbles and boulders. At Sandwich, colonies died that were exposed to air at low tide. The species does not exhibit this seasonal cycle of growth and decline in subtidal habitats (40–65 m) on the Georges Bank fishing grounds where the daily climate is relatively stable and annual water temperatures range from 4 to 15 °C. Experiments in the tide pool with small colony fragments (5 to 9 cm2) show they re-attach and grow rapidly by asexual budding, increasing in size 6- to 11-fold in the first 15 days. Didemnum sp. at Sandwich has no known predators except for common periwinkles (Littorina littorea) that graze on degenerating colonies in the October to April time period and whenever colonies are stressed by desiccation. The tendencies of the ascidian (1) to attach to firm substrates, (2) to rapidly overgrow

  7. Reprotoxicity of the Antifoulant Chlorothalonil in Ascidians: An Ecological Risk Assessment

    Science.gov (United States)

    Gallo, Alessandra; Tosti, Elisabetta

    2015-01-01

    Chlorothalonil is a widely used biocide in antifouling paint formulation that replaces tin-based compounds after their definitive ban. Although chlorothalonil inputs into the marine environment have significantly increased in recent years, little is known about its effect on marine animals and in particular on their reproductive processes. In this line, the aim of the present study was to investigate the effects of chlorothalonil exposure on the gamete physiology, fertilization rate and transmissible damage to offspring in the marine invertebrate Ciona intestinalis (ascidians). To identify a possible mechanism of action of chlorothalonil, electrophysiological techniques were used to study the impact on oocyte membrane excitability and on the electrical events occurring at fertilization. The pre-exposure of spermatozoa and oocytes to chlorothalonil did not affect the fertilization rate but caused damage to the offspring by inducing larval malformation. The highest toxicity was observed when fertilization was performed in chlorothalonil solutions with the lowest EC50 value. In particular, it was observed that low chlorothalonil concentrations interfered with embryo development and led to abnormal larvae, whereas high concentrations arrested embryo formation. In mature oocytes, a decrease in the amplitudes of the sodium and fertilization currents was observed, suggesting an involvement of plasma membrane ion currents in the teratogenic mechanism of chlorothalonil action. The risk estimation confirmed that the predicted no-effect concentration (PNEC) exceeded the predicted effect concentration (PEC), thus indicating that chlorothalonil may pose a risk to aquatic species. PMID:25875759

  8. Recurrent phagocytosis-induced apoptosis in the cyclical generation change of the compound ascidian Botryllus schlosseri.

    Science.gov (United States)

    Franchi, Nicola; Ballin, Francesca; Manni, Lucia; Schiavon, Filippo; Basso, Giuseppe; Ballarin, Loriano

    2016-09-01

    Colonies of the marine, filter-feeding ascidian Botryllus schlosseri undergo cyclical generation changes or takeovers. These events are characterised by the progressive resorption of adult zooids and their replacement by their buds that grow to adult size, open their siphons and start filtering. During the take-over, tissues of adult zooids undergo extensive apoptosis; circulating, spreading phagocytes enter the effete tissues, ingest dying cells acquiring a giant size and a round morphology. Then, phagocytes re-enter the circulation where they represent a considerable fraction (more than 20%) of circulating haemocytes. In this study, we evidence that most of these circulating phagocytes show morphological and biochemical signs of apoptosis. Accordingly, these phagocytes express transcripts of orthologues of the apoptosis-related genes Bax, AIF1 and PARP1. Electron microscopy shows that giant phagocytes contain apoptotic phagocytes inside their own phagocytic vacuole. The transcript of the orthologues of the anti-apoptotic gene IAP7 was detected only in spreading phagocytes, mostly abundant in phases far from the take-over. Therefore, the presented data suggest that, at take-over, phagocytes undergo phagocytosis-induced apoptosis (PIA). In mammals, PIA is assumed to be a process assuring the killing and the complete elimination of microbes, by promoting the disposal of terminally differentiated phagocytes and the resolution of infection. In B. schlosseri, PIA assumes a so far undescribed role, being required for the control of asexual development and colony homeostasis. PMID:27106705

  9. A genomewide analysis of genes for the heat shock protein 70 chaperone system in the ascidian Ciona intestinalis

    OpenAIRE

    Wada, Shuichi; Hamada, Mayuko; Satoh, Nori

    2006-01-01

    Molecular chaperones play crucial roles in various aspects of the biogenesis and maintenance of proteins in the cell. The heat shock protein 70 (HSP70) chaperone system, in which HSP70 proteins act as chaperones, is one of the major molecular chaperone systems conserved among a variety of organisms. To shed light on the evolutionary history of the constituents of the chordate HSP70 chaperone system and to identify all of the components of the HSP70 chaperone system in ascidians, we carried ou...

  10. Metamorphosis of the invasive ascidian Ciona savignyi: environmental variables and chemical exposure.

    Science.gov (United States)

    Cahill, Patrick L; Atalah, Javier; Selwood, Andrew I; Kuhajek, Jeanne M

    2016-01-01

    In this study, the effects of environmental variables on larval metamorphosis of the solitary ascidian Ciona savignyi were investigated in a laboratory setting. The progression of metamorphic changes were tracked under various temperature, photoperiod, substrate, larval density, and vessel size regimes. Metamorphosis was maximised at 18 °C, 12:12 h subdued light:dark, smooth polystyrene substrate, and 10 larvae mL(-1) in a twelve-well tissue culture plate. Eliminating the air-water interface by filling culture vessels to capacity further increased the proportion of metamorphosed larvae; 87 ± 5% of larvae completed metamorphosis within 5 days compared to 45 ± 5% in control wells. The effects of the reference antifouling compounds polygodial, portimine, oroidin, chlorothalonil, and tolylfluanid on C. savignyi were subsequently determined, highlighting (1) the sensitivity of C. savignyi metamorphosis to chemical exposure and (2) the potential to use C. savignyi larvae to screen for bioactivity in an optimised laboratory setting. The compounds were bioactive in the low ng mL(-1) to high µg mL(-1) range. Polygodial was chosen for additional investigations, where it was shown that mean reductions in the proportions of larvae reaching stage E were highly repeatable both within (repeatability = 14 ± 9%) and between (intermediate precision = 17 ± 3%) independent experiments. An environmental extract had no effect on the larvae but exposing larvae to both the extract and polygodial reduced potency relative to polygodial alone. This change in potency stresses the need for caution when working with complex samples, as is routinely implemented when isolating natural compounds from their biological source. Overall, the outcomes of this study highlight the sensitivity of C. savignyi metamorphosis to environmental variations and chemical exposure. PMID:26966668

  11. Local database and the search program for proteomic analysis of sperm proteins in the ascidian Ciona intestinalis

    International Nuclear Information System (INIS)

    Separation of proteins by two-dimensional electrophoresis and following mass spectrometry (MS) is now a conventional technique for proteomic analysis. For proteomic analysis of a certain tissue with a limited information of primary structures of proteins, we have developed an analytical system for peptide mass fingerprinting in gene products in the testis of the ascidian Ciona intestinalis. Ciona sperm proteins were separated by two-dimensional gel electrophoresis and the tryptic fragments were subjected to MALDI-TOF/MS. The mass pattern was searched against on-line databases but resulted in less identification of these proteins. We have constructed a MS database from Ciona testis ESTs and the genome draft sequence, along with a newly devised, perl-based search program PerMS for peptide mass fingerprinting. This system could identify more than 80% of Ciona sperm proteins, suggesting that it could be widely applied for proteomic analysis for a limited tissue with less genomic information

  12. Antimicrobial Activity of the Crude Extracts of Compound Ascidians, Didemnum candidum and Didemnum psammathodes (Tunicata: Didemnidae from Mandapam (South East Coast of India

    Directory of Open Access Journals (Sweden)

    S. Mohamed Hussain

    2009-10-01

    Full Text Available Many cytotoxic compounds of therapeutic interest have been isolated from marine organisms. In thepresent study two species of compound ascidians Didemnum psammathodes and Didemnum candidum wereassayed for their antimicrobial activity against eight bacterial and four fungal pathogens. The antimicrobialactivity of the crude extract of ascidian shows inhibitory activity against almost all the eight strains. However,D. psammathodes shows prominent antibacterial activity than that of Didemnum candidum. Whereas noremarkable antifungal activity was noticed against the ascidian crude extract. The maximum inhibition zone(15 mm was observed against Salmonella typhi in the crude methanol extract of D. psammathodes and theminimum inhibition zone (1 mm was noticed against Vibrio cholera and Staphylococcus aureas in the crudeacetone extract of Didemnum candidum. In D. psammathodes the crude methanol extract the range of inhibitionof the bacteria varied from 2–15 mm with an average of 4.3 mm. According to fungi only Aspergillus niger andPenicillium sp. were showed the trace activity against few crude extract and remaining two fungal pathogensshows negative result. In the present result two way analysis of variance was showing that there was asignificant difference between the extracts as well as the strains (p<0.05.

  13. Identification of Eusynstyelamide B as a Potent Cell Cycle Inhibitor Following the Generation and Screening of an Ascidian-Derived Extract Library Using a Real Time Cell Analyzer

    Directory of Open Access Journals (Sweden)

    Michelle S. Liberio

    2014-10-01

    Full Text Available Ascidians are marine invertebrates that have been a source of numerous cytotoxic compounds. Of the first six marine-derived drugs that made anticancer clinical trials, three originated from ascidian specimens. In order to identify new anti-neoplastic compounds, an ascidian extract library (143 samples was generated and screened in MDA-MB-231 breast cancer cells using a real-time cell analyzer (RTCA. This resulted in 143 time-dependent cell response profiles (TCRP, which are read-outs of changes to the growth rate, morphology, and adhesive characteristics of the cell culture. Twenty-one extracts affected the TCRP of MDA-MB-231 cells and were further investigated regarding toxicity and specificity, as well as their effects on cell morphology and cell cycle. The results of these studies were used to prioritize extracts for bioassay-guided fractionation, which led to the isolation of the previously identified marine natural product, eusynstyelamide B (1. This bis-indole alkaloid was shown to display an IC50 of 5 µM in MDA-MB-231 cells. Moreover, 1 caused a strong cell cycle arrest in G2/M and induced apoptosis after 72 h treatment, making this molecule an attractive candidate for further mechanism of action studies.

  14. Cytotoxicity of actinomycetes associated with the ascidian Eudistoma vannamei (Millar, 1977, endemic of northeastern coast of Brazil

    Directory of Open Access Journals (Sweden)

    Paula C Jimenez

    2013-04-01

    Full Text Available Previous studies demonstrated that the crude extract of the ascidian Eudistoma vannamei, endemic from northeasttern Brazil, strongly hinders growth of tumor cells in vitro by inducing apoptosis due to tryptophan derivatives, which are commonly found in bacteria. This study presents a bioactivity-guided screening among actinomycetes, associated with E. vannamei, aiming at recognizing active principles with biological relevance. Twenty strains of actinomycetes, designated as EVA 0101 through 0120, were isolated from colonies of E. vannamei among which 11 were selected for cytotoxicity evaluation. The extracts from EVA 0102, 0103, 0106, 0109 and 0113 were the most active, and were further studied for IC50 determination and chemical analysis by ¹H NMR. IC50 values obtained ranged from 3.62 µg mL-1 (for EVA 0109 in leukemia cells to 84.65 µg/mL (for EVA 0106 in melanoma cells. All active extracts exhibited the same TLC and spectroscopic profiles, suggesting the presence of quinones and other related secondary metabolites. Furthermore, these strains were identified and compared based on their respective 16S rRNA sequences. The results herein identified the five strains as Micromonospora spp. while phylogenetic analysis suggests that they are possibly two different Micromonospora species producing the cytotoxic compounds.

  15. Msxb is a core component of the genetic circuitry specifying the dorsal and ventral neurogenic midlines in the ascidian embryo.

    Science.gov (United States)

    Roure, Agnès; Darras, Sébastien

    2016-01-01

    The tail ascidian larval peripheral nervous system is made up of epidermal sensory neurons distributed more or less regularly in ventral and dorsal midlines. Their formation occurs in two-steps: the ventral and dorsal midlines are induced as neurogenic territories by Fgf9/16/20 and Admp respectively. The Delta2/Notch interaction then controls the number of neurons that form. The genetic machinery acting between the inductive processes taking place before gastrulation and neuron specification at tailbud stages are largely unknown. The analysis of seven transcription factors expressed in the forming midlines revealed an unexpected complexity and dynamic of gene expression. Their systematic overexpression confirmed that these genes do not interact following a linear cascade of activation. However, the integration of our data revealed the distinct key roles of the two upstream factors Msxb and Nkx-C that are the earliest expressed genes and the only ones able to induce neurogenic midline and ESN formation. Our data suggest that Msxb would be the primary midline gene integrating inputs from the ventral and dorsal inducers and launching a pan-midline transcriptional program. Nkx-C would be involved in tail tip specification, in maintenance of the pan-midline network and in a posterior to anterior wave controlling differentiation. PMID:26592100

  16. Photoresponse and Learning Behavior of Ascidian Larvae, a Primitive Chordate, to Repeated Stimuli of Step-Up and Step-Down of Light

    OpenAIRE

    Kawakami, I.; Shiraishi, S; Tsuda, M

    2002-01-01

    Ascidians are lower chordates and their simple tadpole-like larvae share a basic body plan with vertebrates. Newly hatched larvae show no response to a stimulus of light. 4 h after hatching, the larvae were induced to swim upon a step-down of light and stop swimming upon a step-up of light. At weaker intensity of light, the larvae show the same response to a stimulus after presentation of repeated stimuli. When intensity of actinic light was increased, the larvae show sensitization and habitu...

  17. NK4 antagonizes Tbx1/10 to promote cardiac versus pharyngeal muscle fate in the ascidian second heart field.

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2013-12-01

    Full Text Available The heart and head muscles share common developmental origins and genetic underpinnings in vertebrates, including humans. Parts of the heart and cranio-facial musculature derive from common mesodermal progenitors that express NKX2-5, ISL1, and TBX1. This ontogenetic kinship is dramatically reflected in the DiGeorge/Cardio-Velo-Facial syndrome (DGS/CVFS, where mutations of TBX1 cause malformations in the pharyngeal apparatus and cardiac outflow tract. Cardiac progenitors of the first heart field (FHF do not require TBX1 and segregate precociously from common progenitors of the second heart field (SHF and pharyngeal muscles. However, the cellular and molecular mechanisms that govern heart versus pharyngeal muscle specification within this lineage remain elusive. Here, we harness the simplicity of the ascidian larva to show that, following asymmetric cell division of common progenitors, NK4/NKX2-5 promotes GATAa/GATA4/5/6 expression and cardiac specification in the second heart precursors by antagonizing Tbx1/10-mediated inhibition of GATAa and activation of Collier/Olf/EBF (COE, the determinant of atrial siphon muscle (ASM specification. Our results uncover essential regulatory connections between the conserved cardio-pharyngeal factor Tbx1/10 and muscle determinant COE, as well as a mutual antagonism between NK4 and Tbx1/10 activities upstream of GATAa and COE. The latter cross-antagonism underlies a fundamental heart versus pharyngeal muscle fate choice that occurs in a conserved lineage of cardio-pharyngeal progenitors. We propose that this basic ontogenetic motif underlies cardiac and pharyngeal muscle development and evolution in chordates.

  18. Stochasticity in space, persistence in time: genetic heterogeneity in harbour populations of the introduced ascidian Styela plicata.

    Science.gov (United States)

    Pineda, Mari-Carmen; Lorente, Beatriz; López-Legentil, Susanna; Palacín, Creu; Turon, Xavier

    2016-01-01

    Spatio-temporal changes in genetic structure among populations provide crucial information on the dynamics of secondary spread for introduced marine species. However, temporal components have rarely been taken into consideration when studying the population genetics of non-indigenous species. This study analysed the genetic structure of Styela plicata, a solitary ascidian introduced in harbours and marinas of tropical and temperate waters, across spatial and temporal scales. A fragment of the mitochondrial gene Cytochrome Oxidase subunit I (COI) was sequenced from 395 individuals collected at 9 harbours along the NW Mediterranean coast and adjacent Atlantic waters (> 1,200 km range) at two time points 5 years apart (2009 and 2014). The levels of gene diversity were relatively low for all 9 locations in both years. Analyses of genetic differentiation and distribution of molecular variance revealed strong genetic structure, with significant differences among many populations, but no significant differences among years. A weak and marginally significant correlation between geographic distance and gene differentiation was found. Our results revealed spatial structure and temporal genetic homogeneity in S. plicata, suggesting a limited role of recurrent, vessel-mediated transport of organisms among small to medium-size harbours. Our study area is representative of many highly urbanized coasts with dense harbours. In these environments, the episodic chance arrival of colonisers appears to determine the genetic structure of harbour populations and the genetic composition of these early colonising individuals persists in the respective harbours, at least over moderate time frames (five years) that encompass ca. 20 generations of S. plicata. PMID:27366653

  19. Bigger is not always better: offspring size does not predict growth or survival for seven ascidian species.

    Science.gov (United States)

    Jacobs, Molly W; Sherrard, Kristin M

    2010-12-01

    The presumed trade-off between offspring size and quality predicted by life history theory is often invoked to explain the wide range of propagule sizes observed in animals and plants. This trade-off is broadly supported by intraspecific studies but has been difficult to test in an interspecific context, particularly in animals. We tested the fitness consequences of offspring size both intra- and interspecifically for seven species of ascidians (sessile, suspension-feeding, marine invertebrates) whose offspring volumes varied over three orders of magnitude. We measured two major components of fitness, juvenile growth rates and survival, in laboratory and field experiments encompassing several food conditions. Contrary to the predictions of life history theory, larger offspring size did not result in higher rates of growth or survival, and large offspring did not perform better under nutritional stress, either intraspecifically or interspecifically. In fact, two of the four species with small offspring grew rapidly enough to catch up in size to the species with large offspring in as little as eight weeks, under wild-type food conditions. Trade-offs between growth potential and defense may overwhelm and obscure any trade-offs between offspring size and survival or growth rate. While large initial size may still confer a competitive advantage, we failed to detect any consequences of interspecific variation in initial size. This implies that larger offspring in these species, far from being inherently superior in growth or survival, require compensation in other aspects of life history if reproductive effort is to be efficient. Our results suggest that the importance of initial offspring size is context dependent and often overestimated relative to other life history traits. PMID:21302831

  20. Suppression of cell-spreading and phagocytic activity on nano-pillared surface: in vitro experiment using hemocytes of the colonial ascidian Botryllus schlosseri

    Directory of Open Access Journals (Sweden)

    L Ballarin

    2015-02-01

    Full Text Available Nano-scale nipple array on the body surface has been described from various invertebrates including endoparasitic and mesoparasitic copepods, but the functions of the nipple array is not well understood. Using the hydrophilized nanopillar sheets made of polystyrene as a mimetic material of the nipple arrays on the parasites’ body surface, we assayed the cell spreading and phagocytosis of the hemocytes of the colonial ascidian Botryllus schlosseri. On the pillared surface, the number of spreading amebocytes and the number of phagocytizing hemocytes per unit area were always smaller than those on the flat surface (Mann-Whitney test, p < 0.05 - 0.001, probably because the effective area for the cell attachment on the pillared surface is much smaller than the area on the flat sheet. The present results supports the idea that the nipple array on the parasites' body surface reduces the innate immune reaction from the host hemocytes.

  1. An ultraviolet-sensitive maternal mRNA encoding a cytoskeletal protein may be involved in axis formation in the ascidian embryo

    International Nuclear Information System (INIS)

    Ultraviolet (uv) irradiation of the vegetal hemisphere of fertilized eggs during ooplasmic segregation inhibits subsequent gastrulation and axis formation in ascidian embryos. The molecular basis of this phenomenon was investigated in by comparing in vivo protein synthesis and in vitro mRNA translation in normal and uv-irradiated embryos of the ascidian Styela clava. Analysis of protein synthesis by [35S]methionine incorporation, two-dimensional (2D) gel electrophoresis, and autoradiography showed that only 21 of 433 labeled polypeptides were missing or decreased in labeling intensity in uv-irradiated embryos. The most prominent of these was a 30,000 molecular weight (pI 6.0) polypeptide (p30). Extraction of gastrulae with the nonionic detergent Triton X-100 showed that p30 is retained in the detergent insoluble residue, suggesting that it is associated with the cytoskeleton. Several lines of evidence suggest that p30 may be involved in axis formation. First, p30 labeling peaks during gastrulation, when the embryonic axis is being established. Second, axis formation and p30 labeling are abolished by the same threshold uv dose, which is distinct from that required to inactivate muscle cell development. Third, the uv sensitivity period for abolishing p30 labeling and axis formation are both restricted to ooplasmic segregation. In vitro translation of egg RNA followed by 2D gel electrophoresis and autoradiography of the protein products showed that p30 is encoded by a maternal mRNA. The translation of p30 mRNA was abolished by uv irradiation of fertilized eggs during ooplasmic segregation suggesting that this message is a uv-sensitive target. The results are consistent with the hypothesis that uv irradiation blocks gastrulation and axis formation by inhibiting the translation of maternal mRNA localized in the vegetal hemisphere of the fertilized egg

  2. Natural products from the ascidian Botrylloides giganteum, from the sponges Verongula gigantea, Ircinia felix, Cliona delitrix and from the nudibranch Tambja eliora, from the Brazilian coastline

    International Nuclear Information System (INIS)

    Two new marine metabolites, 3Z, 6Z, 9Z-dodecatrien-1-ol (1) from the ascidian Botrylloides giganteum and 4H-pyran-2ol acetate from the sponge Ircinia felix (4) are herein reported. The known bromotyrosine compounds, 2-(3,5-dibromo-4-methoxyphenyl)-N,N,Ndimethylethanammonium (2) and 2,6-dibromo-4-(2-(trimethylammonium)ethyl)phenol (3), have been isolated from the sponge Verongula gigantea. Serotonin (5) is reported for the first time from the sponge Cliona delitrix, and tambjamines A (15) and D (16) isolated as their respective salts from the nudibranch Tambja eliora. Only tambjamine D presented cytotoxicity against CEM (IC5)0 12.2 μg/mL) and HL60 (IC50 13.2 μg/mL) human leukemia cells, MCF-7 breast cancer cells (IC50 13.2 μg/mL), colon HCT-8 cancer cells (IC50 10.1 μg/mL) and murine melanoma B16 cancer cells (IC50 6.7 μg/mL). (author)

  3. First in situ observations of the deep-sea carnivorous ascidian Dicopia antirrhinum Monniot C., 1972 in the Western Mediterranean Sea

    Science.gov (United States)

    Mecho, A.; Aguzzi, J.; Company, J. B.; Canals, M.; Lastras, G.; Turon, X.

    2014-01-01

    Dicopia antirrhinum C. Monniot, 1972 is a rare species of deep-sea ascidian belonging to the Family Octacnemidae, reported at depths of 1000-2500 m in European Atlantic waters. Adult individuals have never been reported before in the Mediterranean Sea, where only seven juvenile specimens were found in 1975 at 500 m water depth in the Central basin (Malta). The affinities of these specimens with D. antirrhinum were noted, but lack of some typical characters of the species in juveniles prevented a definite taxonomical identification. No other member of the Octacnemidae has ever been found in the Mediterranean. In this study we describe the sampling of an adult specimen of D. antirrhinum at around 1100 m water depth on the flank of the La Fonera (Palamós) canyon, Northwestern Mediterranean, confirming their presence in the Mediterranean Sea. We also observed 5 individuals of this species on their natural habitat with a Remotely Operated Vehicle (ROV). Our results highlight the potential occurrence of Octacnemidae, the presence of which has been largely overlooked, in several deep-sea canyon areas within the Western Mediterranean basin. These observations are important because they indicate the need for increased sampling effort with new technologies, such as ROVs, in ecologically relevant habitats such as canyons, in order to obtain a more accurate picture of deep-sea biodiversity in the Mediterranean Sea.

  4. Nitric oxide affects ERK signaling through down-regulation of MAP kinase phosphatase levels during larval development of the ascidian Ciona intestinalis.

    Directory of Open Access Journals (Sweden)

    Immacolata Castellano

    Full Text Available In the ascidian Ciona intestinalis larval development and metamorphosis require a complex interplay of events, including nitric oxide (NO production, MAP kinases (ERK, JNK and caspase-3 activation. We have previously shown that NO levels affect the rate of metamorphosis, regulate caspase activity and promote an oxidative stress pathway, resulting in protein nitration. Here, we report that NO down-regulates MAP kinase phosphatases (mkps expression affecting positively ERK signaling. By pharmacological approach, we observed that the reduction of endogenous NO levels caused a decrease of ERK phosphorylation, whereas increasing levels of NO induced ERK activation. We have also identified the ERK gene network affected by NO, including mpk1, mpk3 and some key developmental genes by quantitative gene expression analysis. We demonstrate that NO induces an ERK-independent down-regulation of mkp1 and mkp3, responsible for maintaining the ERK phosphorylation levels necessary for transcription of key metamorphic genes, such as the hormone receptor rev-erb and the van willebrand protein vwa1c. These results add new insights into the role played by NO during larval development and metamorphosis in Ciona, highlighting the cross-talk between different signaling pathways.

  5. Dicty_cDB: VSH642 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available acidic repetitive protein arp1 - Tetrahymena ther... 35 1.4 AB276041_1( AB276041...ucing significant alignments: (bits) Value AL929357_40( AL929357 |pid:none) Plasmodium falciparum strain 3D7... |pid:none) Halocynthia roretzi mRNA for HrUra... 34 4.1 AF533700_1( AF533700 |pid:none) Plasmodium falcipar...929_1( AF411929 |pid:none) Plasmodium falciparum strain FVO n... 33 5.3 CU633453_...VS (Link to library) VSH642 (Link to dictyBase) - - - Contig-U13431-1 VSH642P (Link

  6. The colonial ascidian Didemnum sp. A: current distribution, basic biology and potential threat to marine communities of the northeast and west coasts of North America

    Science.gov (United States)

    Bullard, S.G.; Lambert, G.; Carman, M.R.; Byrnes, J.; Whitlatch, R.B.; Ruiz, G.; Miller, R.J.; Harris, L.; Valentine, P.C.; Collie, J.S.; Pederson, J.; McNaught, D.C.; Cohen, A.N.; Asch, R.G.; Dijkstra, J.; Heinonen, K.

    2007-01-01

    Didemnum sp. A is a colonial ascidian with rapidly expanding populations on the east and west coasts of North America. The origin of Didemum sp. A is unknown. Populations were first observed on the northeast coast of the U.S. in the late 1980s and on the west coast during the 1990s. It is currently undergoing a massive population explosion and is now a dominant member of many subtidal communities on both coasts. To determine Didemnum sp. A's current distribution, we conducted surveys from Maine to Virginia on the east coast and from British Columbia to southern California on the west coast of the U.S. between 1998 and 2005. In nearshore locations Didemnum sp. A currently ranges from Eastport, Maine to Shinnecock Bay, New York on the east coast. On the west coast it has been recorded from Humboldt Bay to Port San Luis in California, several sites in Puget Sound, Washington, including a heavily fouled mussel culture facility, and several sites in southwestern British Columbia on and adjacent to oyster and mussel farms. The species also occurs at deeper subtidal sites (up to 81 m) off New England, including Georges, Stellwagen and Tillies Banks. On Georges Bank numerous sites within a 230 km2 area are 50–90% covered by Didemnum sp. A; large colonies cement the pebble gravel into nearly solid mats that may smother infaunal organisms. These observations suggest that Didemnum sp. A has the potential to alter marine communities and affect economically important activities such as fishing and aquaculture.

  7. Signaling pathways in ascidian oocyte maturation: the roles of cAMP/Epac, intracellular calcium levels, and calmodulin kinase in regulating GVBD.

    Science.gov (United States)

    Lambert, Charles C

    2011-01-01

    Most mature ascidian oocytes undergo germinal vesicle breakdown (GVBD) when released by the ovary into sea water (SW). Acidic SW blocks this but they can be stimulated by raising the pH, increasing intracellular cAMP levels by cell permeant forms, inhibiting its breakdown or causing synthesis. Boltenia villosa oocytes undergo GVBD in response to these drugs. However, the cAMP receptor protein kinase A (PKA) does not appear to be involved, as oocytes are not affected by the kinase inhibitor H-89. Also, the PKA independent Epac agonist 8CPT-2Me-cAMP stimulates GVBD in acidic SW. GVBD is inhibited in calcium free sea water (CaFSW). The intracellular calcium chelator BAPTA-AM blocks GVBD at 10 µM. GVBD is also inhibited when the ryanodine receptors (RYR) are blocked by tetracaine or ruthenium red but not by the IP(3) inhibitor D-609. However, dimethylbenzanthracene (DMBA), a protein kinase activator, stimulates GVBD in BAPTA, tetracaine or ruthenium red blocked oocytes. The calmodulin kinase inhibitor KN-93 blocks GVBD at 10 µM. This and preceding papers support the hypothesis that the maturation inducing substance (MIS) produced by the follicle cells in response to increased pH causes activation of a G protein which triggers cAMP synthesis. The cAMP then activates an Epac molecule, which causes an increase in intracellular calcium from the endoplasmic reticulum ryanodine receptor. The increased intracellular calcium subsequently activates calmodulin kinase, which causes an increase in cdc25 phosphatase activity, activating MPF and the progression of the oocyte into meiosis. PMID:21774024

  8. Isolation and biological activities of secondary metabolites from the sponges monanchora aff. arbuscula, aplysina sp. petromica ciocalyptoides and topsentia ophiraphidies, from the ascidian didemnum ligulum and from the octocoral carijoa riisei

    International Nuclear Information System (INIS)

    The investigation of extracts from six species of marine invertebrates yielded one new and several known natural products. Isoptilocaulin from the sponge Monanchora aff. arbuscula displayed antimicrobial activity at 1.3 mg/mL against an oxacillin-resistant strain of Staphylococcus aureus. Five inactive known dibromotyrosine derivatives, 2 6, were isolated from a new species of marine sponge, Aplysina sp. The sponges Petromica ciocalyptoides and Topsentia ophiraphidites yielded the known halistanol sulfate A (7) as an inhibitor of the antileishmanial target adenosine phosphoribosyl transferase. The ascidian Didemnum ligulum yielded asterubin (10) and the new N,N-dimethyl-O-methylethanolamine (11). The octocoral Carijoa riisei yielded the known 18-acetoxypregna-1,4,20-trien-3-one (12), which displayed cytotoxic activity against the cancer cell lines SF295, MDA-MB435, HCT8 and HL60. (author)

  9. Ascídias (Tunicata, Ascidiacea da Reserva Biológica Marinha do Arvoredo, Santa Catarina, Brasil Ascidians (Tunicata, Ascidiacea from the Arvoredo Marine Biological Reserve, Santa Catarina, Brazil

    Directory of Open Access Journals (Sweden)

    Rosana M. da Rocha

    2005-06-01

    Full Text Available A Reserva Biológica Marinha de Arvoredo compreende uma extensa área (17.800 ha, onde se elevam as ilhas do Arvoredo, Galé, Deserta e calhau de São Pedro. O levantamento de espécies de ascídias foi realizado por meio de mergulho autônomo m águas rasas (5-17 m de profundidade. Vinte e seis espécies são aqui registradas, entre as quais Lissoclinum perforatum (Giard, 1872, L. verrilli (Van Name, 1902 e Leptoclinides latus Monniot, 1983 representam novos registros para o Brasil, e outras 19 espécies representam novos registros para o Estado de Santa Catarina. Com este resultado, 34 espécies de ascídias já foram registradas em Santa Catarina, das quais 22 são marcadamente tropicais. Este cenário não representa a diversidade total da Reserva, uma vez que três espécies novas serão descritas em outra publicação e os locais mais expostos e profundos das ilhas não foram amostrados.The Arvoredo Marine Biological Reserve covers an extensive area including the islands Arvoredo, Galés and Deserta and a small rocky outcrop called São Pedro. The survey of ascidians was accomplished with scuba dive, only in shallow water (5-17 m deep. Twenty-six species are here registered, among which Lissoclinum perforatum (Giard, 1872, L. verrilli (Van Name, 1902 and Leptoclinides latus Monniot, 1983 represent new reports to Brazil, and other 19 species represent new reports to the State of Santa Catarina. Together with the results of the present work, 34 ascidian species have already been reported from Santa Catarina, of the which 22 are remarkably tropical. This scenery doesn't represent the total diversity of the Reserve, since three new species will be described in another publication and the most exposed and deep places of the islands were not sampled.

  10. Dicty_cDB: Contig-U02377-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available cDNA clone:ddc25c23, 3' ... 58 2e-27 6 ( DN294814 ) PL03018A1F10 cDNA from sexually mature hermaphodi... 78 ...ematobia irritans eggs Haematobia irr... 111 5e-23 2 ( DN300352 ) PL04019A1B11 cDNA from sexually mature her...maphodi... 78 1e-22 4 ( DN293081 ) PL030012B20B12 cDNA from sexually mature hermapho... 78 2e-22 4 ( DB62546...1 ) Halocynthia roretzi cDNA clone:man2a21, 5' end. 68 2e-22 4 ( DN296131 ) PL04005A1D01 cDNA from sexually ...mature hermaphodi... 78 2e-22 4 ( DN300512 ) PL04019B1D01 cDNA from sexually matu

  11. Dicty_cDB: SLI827 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available g significant alignments: (bits) Value N AF073837 |AF073837.1 Dictyostelium discoideum calnexin precursor, gene, co...AB047037_1( AB047037 |pid:none) Halocynthia roretzi HrCalnexin mRN... 68 2e-10 (Q3SYT6) RecName: Full=Calmegin...715... 68 2e-10 FN314644_1( FN314644 |pid:none) Schistosoma japonicum isolate Anhu... 68 2e-10 A46637( A46637 ) calnexin... homolog SmIrV1 - fluke (Schistosoma mans... 68 2e-10 ( P35565 ) RecName: Full=Calnexin; Flags: ...Precursor; &C54354(C543... 68 2e-10 AY100687_1( AY100687 |pid:none) Cricetulus griseus calnexin mRNA, ... 68 2e-10 protein

  12. Dicty_cDB: SSD559 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 0.60 A54138( A54138 ) acidic repetitive protein arp1 - Tetrahymena ther... 35 1.7 AB276041_1( AB276041 |pid:...significant alignments: (bits) Value AL844508_198( AL844508 |pid:none) Plasmodium falcipar...um 3D7 chromo... 40 0.093 AL844506_47( AL844506 |pid:none) Plasmodium falciparum 3D7 chromos... 37 ...none) Halocynthia roretzi mRNA for HrUra... 34 5.1 AF533700_1( AF533700 |pid:none) Plasmodium falcipar...um 3D7 normocyt... 33 6.6 AF411929_1( AF411929 |pid:none) Plasmodium falciparum strain

  13. Dicty_cDB: SSK549 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available um 3D7 chromos... 37 0.25 A54138( A54138 ) acidic repetitive protein arp1 - Tetrahymena ther... 37 0.33...na genomic DNA, chromosome 5, TAC clone:K18P6. 46 0.41 1 AV082420 |AV082420.1 Mus musculus adult male tongue cDNA, par...4508 |pid:none) Plasmodium falciparum 3D7 chromo... 40 0.039 AL844506_47( AL844506 |pid:none) Plasmodium falcipar... AB276041_1( AB276041 |pid:none) Halocynthia roretzi mRNA for HrUra... 35 0.96 AF533700_1( AF533700 |pid:none) Plasmodium falcipar...um 3D7 normocyt... 35 1.3 AF411929_1( AF411929 |pid:none) Plasmodium falcipar

  14. Dicty_cDB: SSI260 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 0.17 A54138( A54138 ) acidic repetitive protein arp1 - Tetrahymena ther... 37 0.28 AB276041_1( AB276041 |pi...Score E Sequences producing significant alignments: (bits) Value AL844508_198( AL844508 |pid:none) Plasmodium falcipar...um 3D7 chromo... 40 0.033 AL844506_47( AL844506 |pid:none) Plasmodium falciparum 3D7 chromos... 37...d:none) Halocynthia roretzi mRNA for HrUra... 35 0.82 AF533700_1( AF533700 |pid:none) Plasmodium falcipar...um 3D7 normocyt... 35 1.1 AF411929_1( AF411929 |pid:none) Plasmodium falciparum stra

  15. Dermatan sulfate in tunicate phylogeny: Order-specific sulfation pattern and the effect of [→4IdoA(2-Sulfate)β-1→3GalNAc(4-Sulfate)β-1→] motifs in dermatan sulfate on heparin cofactor II activity

    OpenAIRE

    Sugahara Kazuyuki; Bao Xingfeng; Vicente Cristina P; Lotufo Tito; Lima Paula C; Kozlowski Eliene O; Pavão Mauro SG

    2011-01-01

    Abstract Background Previously, we have reported the presence of highly sulfated dermatans in solitary ascidians from the orders Phlebobranchia (Phallusia nigra) and Stolidobranchia (Halocynthia pyriformis and Styela plicata). Despite the identical disaccharide backbone, consisting of [→4IdoA(2S)β-1→3GalNAcβ-1→], those polymers differ in the position of sulfation on the N-Acetyl galactosamine, which can occur at carbon 4 or 6. We have shown that position rather than degree of sulfation is imp...

  16. Isolation and biological activities of secondary metabolites from the sponges monanchora aff. arbuscula, aplysina sp. petromica ciocalyptoides and topsentia ophiraphidies, from the ascidian didemnum ligulum and from the octocoral carijoa riisei; Isolamento e atividades biologicas de produtos naturais das esponjas monanchora arbuscula, aplysina sp., petromica ciocalyptoides e topsentia ophiraphidites, da ascidia didemnum ligulum e do octocoral carijoa riisei

    Energy Technology Data Exchange (ETDEWEB)

    Kossuga, Miriam H.; Lira, Simone P. de; Nascimento, Andrea M.; Gambardella, Maria Teresa P.; Berlinck, Roberto G.S. [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Inst. de Quimica]. E-mail: rgsberlinck@iqsc.usp.br; Torres, Yohandra R. [Universidade Estadual do Centro-Oeste, Guarapuava, PR (Brazil). Dept. de Quimica; Nascimento, Gislene G.F. [Universidade Metodista de Piracicaba (UNIMEP), SP (Brazil). Faculdade de Ciencias da Saude; Pimenta, Eli F.; Silva, Marcio; Thiemann, Otavio H.; Oliva, Glaucius [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Inst. de Fisica; Tempone, Andre G.; Melhem, Marcia S.C. [Instituto Adolfo Lutz, Sao Paulo, SP (Brazil). Div. de Biologia Medica; Souza, Ana O. de; Galetti, Fabio C.S.; Silva, Celio L. [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Dept. de Bioquimica e Imunologia; Cavalcanti, Bruno; Pessoa, Claudia O.; Moraes, Manoel O. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Faculdade de Medicina. Dept. de Fisiologia e Farmacologia; Hajdu, Eduardo [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Museu Nacional; Peixinho, Solange [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Dept. de Biologia; Rocha, Rosana M. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Setor de Ciencias Biologicas. Dept. de Zoologia

    2007-09-15

    The investigation of extracts from six species of marine invertebrates yielded one new and several known natural products. Isoptilocaulin from the sponge Monanchora aff. arbuscula displayed antimicrobial activity at 1.3 mg/mL against an oxacillin-resistant strain of Staphylococcus aureus. Five inactive known dibromotyrosine derivatives, 2 6, were isolated from a new species of marine sponge, Aplysina sp. The sponges Petromica ciocalyptoides and Topsentia ophiraphidites yielded the known halistanol sulfate A (7) as an inhibitor of the antileishmanial target adenosine phosphoribosyl transferase. The ascidian Didemnum ligulum yielded asterubin (10) and the new N,N-dimethyl-O-methylethanolamine (11). The octocoral Carijoa riisei yielded the known 18-acetoxypregna-1,4,20-trien-3-one (12), which displayed cytotoxic activity against the cancer cell lines SF295, MDA-MB435, HCT8 and HL60. (author)

  17. Isolamento e atividades biológicas de produtos naturais das esponjas monanchora arbuscula, aplysina sp. petromica ciocalyptoides e topsentia ophiraphidites, da ascídia didemnum ligulum e do octocoral carijoa riisei Isolantion and biological activities of secondary metabolites from the sponges monanchora aff. arbuscula, aplysina sp. petromica ciocalyptoides and topsentia ophiraphidies, from the ascidian didemnum ligulum and from the octocoral carijoa riisei

    Directory of Open Access Journals (Sweden)

    Miriam H. Kossuga

    2007-10-01

    Full Text Available The investigation of extracts from six species of marine invertebrates yielded one new and several known natural products. Isoptilocaulin from the sponge Monanchora aff. arbuscula displayed antimicrobial activity at 1.3 mg/mL against an oxacillin-resistant strain of Staphylococcus aureus. Five inactive known dibromotyrosine derivatives, 2 6, were isolated from a new species of marine sponge, Aplysina sp. The sponges Petromica ciocalyptoides and Topsentia ophiraphidites yielded the known halistanol sulfate A (7 as an inhibitor of the antileishmanial target adenosine phosphoribosyl transferase. The ascidian Didemnum ligulum yielded asterubin (10 and the new N,N-dimethyl-O-methylethanolamine (11. The octocoral Carijoa riisei yielded the known 18-acetoxypregna-1,4,20-trien-3-one (12, which displayed cytotoxic activity against the cancer cell lines SF295, MDA-MB435, HCT8 and HL60.

  18. Produtos naturais da ascídia Botrylloides giganteum, das esponjas Verongula gigantea, Ircinia felix, Cliona delitrix e do nudibrânquio Tambja eliora, da costa do Brasil Natural products from the ascidian Botrylloides giganteum, from the sponges Verongula gigantea, Ircinia felix, Cliona delitrix and from the nudibranch Tambja eliora, from the Brazilian coastline

    Directory of Open Access Journals (Sweden)

    Ana Claudia Granato

    2005-03-01

    Full Text Available Two new marine metabolites, 3Z, 6Z, 9Z-dodecatrien-1-ol (1 from the ascidian Botrylloides giganteum and 4H-pyran-2ol acetate from the sponge Ircinia felix (4 are herein reported. The known bromotyrosine compounds, 2-(3,5-dibromo-4-methoxyphenyl-N,N,N-dimethylethanammonium (2 and 2,6-dibromo-4-(2-(trimethylammoniumethylphenol (3, have been isolated from the sponge Verongula gigantea. Serotonin (5 is reported for the first time from the sponge Cliona delitrix, and tambjamines A (15 and D (16 isolated as their respective salts from the nudibranch Tambja eliora. Only tambjamine D presented cytotoxicity against CEM (IC50 12.2 µg/mL and HL60 (IC50 13.2 µg/mL human leukemya cells, MCF-7 breast cancer cells (IC50 13.2 µg/mL, colon HCT-8 cancer cells (IC50 10.1 µg/mL and murine melanoma B16 cancer cells (IC50 6.7 µg/mL.

  19. Recruitment and colonization of colonial ascidians (Tunicata: Ascidiacea on intertidal rocks in Northeastern Brazil Recrutamento e colonização de ascídias coloniais (Tunicata: Ascidiacea em rochas de entre-marés no nordeste do Brasil

    Directory of Open Access Journals (Sweden)

    Petrônio Bezerra Gama

    2006-06-01

    Full Text Available Recruitment and colonization of colonial ascidians, starting on natural scraped substratum, was observed throughout one year, in quadrats marked on sea- and continental-rock faces in the sublittoral fringe of an exposed beach in the Northeast of Brazil. The species of the Didemnidae, Didemnum duplicatum Monniot, 1983, D. psammathodes Sluiter, 1895, and Polysyncraton amethysteum Van Name, 1902, and an unidentified species of Polycitoridae, Eudistoma sp. 1, were recruited. Presenting continuous recruitment of all species, the density of living and dead recruits and colonies was similar on both faces of the rocks. The highest rainfall during winter, affected significantly the recruits density of D. duplicatum and D. psammathodes. Different permanence periods were observed for colonies of each species. The longest permanence periods were assigned to the colonies of P. amethysteum and D. psammathodes, extending up to four and five months, respectively.A partir de substrato natural raspado, o recrutamento e a colonização de ascídias coloniais foi observado ao longo de um ano, em unidades amostrais delimitadas sobre as faces mar e continente de rochas situadas na franja do infralitoral de uma praia exposta no nordeste do Brasil. Foram recrutadas as espécies de Didemnidae, Didemnum duplicatum Monniot, 1983, D. psammathodes Sluiter, 1895 e Polysyncraton amethysteum Van Name, 1902 e uma espécie não-identificada de Polycitoridae, Eudistoma sp. 1. Apresentando recrutamento contínuo de todas as espécies, a densidade de colônias e de recrutas vivos e mortos foi similar nas duas faces das rochas. Durante o inverno, a densidade de recrutas de D. duplicatum e de D. psammathodes foi significativamente afetada pela intensa pluviosidade. As colônias de cada espécie apresentaram diferentes períodos de permanência sobre as rochas. Com duração de quatro e cinco meses, os maiores períodos de permanência foram assinalados para as colônias de P

  20. Determination of toxic heavy metals in Echinodermata and Chordata species from South Korea.

    Science.gov (United States)

    Choi, Ji Yeon; Habte, Girum; Khan, Naeem; Nho, Eun Yeong; Hong, Joon Ho; Choi, Hoon; Park, Kyung Su; Kim, Kyong Su

    2014-01-01

    This study aimed at analysing concentrations of heavy metals including arsenic, lead, cadmium, aluminium and mercury in commonly consumed seafood species belonging to Echinodermata (Anthocidaris crassispina and Stichopus japonicus) and Chordata (Halocynthia roretzi and Styela plicata). The samples were digested by a microwave system and analysed for As, Cd and Pb by inductively coupled plasma mass spectrometer, for Al by inductively coupled plasma-optical emission spectrometer and Hg by Direct Mercury Analyser. The analytical method was validated by determining sensitivity, linearity, precision, spiking recoveries and analysis of the Standard Reference Material (SRM) NIST 1566-b, an Oyster Tissue. Results showed considerably higher accumulation of Al and As in analysed samples, compared to Pb and Cd, while Hg had the lowest contamination. On comparison, the obtained results with the recommended standards by the Food and Agriculture Organization, European Commission and Ministry of Food and Drug Safety of Korea, it was concluded that the analysed seafoods were safe and thus would not pose a threat to consumers. PMID:24916139

  1. Bioadhesion in ascidians: a developmental and functional genomics perspective

    OpenAIRE

    Pennati, Roberta; Rothbächer, Ute

    2015-01-01

    The development of bioadhesives inspired from marine animals is a promising approach to generate new tissue-compatible medical components. A number of marine species, through their adhesive properties, also represent significant foulers that become increasingly problematic to aquaculture, shipping or local biodiversity. In order to develop more sophisticated man-made glues and/or efficient fouling resistant surfaces, it is important to understand the mechanical, structural and molecular prope...

  2. Purification of Mitochondrial Proteins HSP60 and ATP Synthase from Ascidian Eggs: Implications for Antibody Specificity

    OpenAIRE

    Chenevert, Janet; Pruliere, Gerard; Ishii, Hirokazu; Sardet, Christian; Nishikata, Takahito

    2013-01-01

    Use of antibodies is a cornerstone of biological studies and it is important to identify the recognized protein with certainty. Generally an antibody is considered specific if it labels a single band of the expected size in the tissue of interest, or has a strong affinity for the antigen produced in a heterologous system. The identity of the antibody target protein is rarely confirmed by purification and sequencing, however in many cases this may be necessary. In this study we sought to chara...

  3. Ascidian dermatan sulfates attenuate metastasis, inflammation and thrombosis by inhibition of P-selectin

    OpenAIRE

    Kozlowski, E; M.S.G. Pavão; Borsig, L

    2011-01-01

    Background: Cancer-associated thrombosis and enduring inflammation are strongly associated with cancer progression and metastasis. Heparin is the mostly clinically used anticoagulant/antithrombotic drug, and has recently been shown to exhibit antimetastatic and anti-inflammatory activities that are linked to inhibition of P-selectin and/or L-selectin. P-selectin-mediated platelet–tumor cell and tumor cell–endothelium interactions facilitate the initial steps of metastasis. Objectives and Meth...

  4. Allogeneic Responses between Three Remote Populations of the Cosmopolitan Ascidian Botryllus schlosseri(Immunology)

    OpenAIRE

    Rinkevich, Baruch; Shapira, Michal; Weissman, Irving L.; Saito, Yasunori

    1992-01-01

    Colony allorecognition assays (CAAs) were performed between colonies of the world-wide distributed tunicate Botryllus schlosseri, sampled from the Mediterranean coast of Israel (Is), from Monterey, California (Mon) and from Mutsu Bay, Japan (Ja). While all 48 Is vs Ja CAAs resulted in nonfusion responses, unexpectedly, 4.4% of the 45 Is vs Mon pairs and 12.0% of the 25 Ja vs Mon assays ended in colony fusions. Allogeneic effector mechanisms in all 3 populations were similar, except for the Ja...

  5. Fungicidal compounds from a marine Ascidian-associated fungus Trichoderma harzianum

    Digital Repository Service at National Institute of Oceanography (India)

    PrabhaDevi; Ciavatta, M.L.; Wahidullah, S.; Vuppala, S.; DeSouza, L.

    . Of the five isolated secondary metabolites, compounds 2 and 5 are being reported here for the first time from T. harzianum. Compounds 1 and 4 inhibited the growth of Sclerotium rolfsii causing sclerotium wilt or rot disease in tropical plants. Compound 2 and 5...

  6. A Maternal System Initiating the Zygotic Developmental Program through Combinatorial Repression in the Ascidian Embryo

    Science.gov (United States)

    Oda-Ishii, Izumi; Kubo, Atsushi; Kari, Willi; Suzuki, Nobuhiro; Rothbächer, Ute

    2016-01-01

    Maternal factors initiate the zygotic developmental program in animal embryos. In embryos of the chordate, Ciona intestinalis, three maternal factors—Gata.a, β-catenin, and Zic-r.a—are required to establish three domains of gene expression at the 16-cell stage; the animal hemisphere, vegetal hemisphere, and posterior vegetal domains. Here, we show how the maternal factors establish these domains. First, only β-catenin and its effector transcription factor, Tcf7, are required to establish the vegetal hemisphere domain. Second, genes specifically expressed in the posterior vegetal domain have additional repressive cis-elements that antagonize the activity of β-catenin/Tcf7. This antagonizing activity is suppressed by Zic-r.a, which is specifically localized in the posterior vegetal domain and binds to DNA indirectly through the interaction with Tcf7. Third, Gata.a directs specific gene expression in the animal hemisphere domain, because β-catenin/Tcf7 weakens the Gata.a-binding activity for target sites through a physical interaction in the vegetal cells. Thus, repressive regulation through protein-protein interactions among the maternal transcription factors is essential to establish the first distinct domains of gene expression in the chordate embryo. PMID:27152625

  7. Intense predation on ascidians by a trunk fish, Ostracion immaculatus (Temminck et Schlege) (Pisces:Ostracidae)

    Digital Repository Service at National Institute of Oceanography (India)

    Raveendran, T.V.; Harada, E.

    stream_size 9 stream_content_type text/plain stream_name Publ_Seto_Mar_Biol_Lab_37_193.pdf.txt stream_source_info Publ_Seto_Mar_Biol_Lab_37_193.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  8. Data on the ascidians (Chordata, Ascidiacea) of the marine park of Zembra-Zembretta (North Tunisia)

    OpenAIRE

    Mestiri, M.; Espla Alfonso, R.A.; Ben Mustapha, K.; M.S. ROMDHANE

    2005-01-01

    Une étude systématique des ascidies du Parc marin de Zembra-Zembretta a été menée. L’échantillonnage effectué autour de ces îles a été réalisé, pour la majorité des espèces, par scaphandre autonome sur les substrats rocheux et l’herbier à Posidonia oceanica et aussi par dragage sur les fonds meubles (sable et détritique côtier). La profondeur varie selon les stations de 14 à 70m. Au total, une vingtaine d’espèces a été recensée. Elles appartiennent à 6 familles (Polyclinidae, Polycitoridae, D...

  9. Evolutionary mitogenomics of Chordata: the strange case of ascidians and vertebrates

    OpenAIRE

    C Gissi; Griggio, F.; F. Iannelli

    2009-01-01

    The availability of almost one thousand complete mitochondrial genome (mtDNA) sequences of chordates provides an almost unique opportunity to analyse the evolution of this genome in the phylum Chordata, and to identify possible divergent evolutionary trends followed by the three chordate subphyla: Vertebrata, Cephalochordata and Tunicata.Here, we review some genome-level features of mtDNA, such as genetic code, gene content, genome architecture and gene strand asymmetry, mostly focusing on di...

  10. Evolutionary mitogenomics of Chordata: the strange case of ascidians and vertebrates

    Directory of Open Access Journals (Sweden)

    C Gissi

    2009-03-01

    Full Text Available The availability of almost one thousand complete mitochondrial genome (mtDNA sequences of chordates provides an almost unique opportunity to analyse the evolution of this genome in the phylum Chordata, and to identify possible divergent evolutionary trends followed by the three chordate subphyla: Vertebrata, Cephalochordata and Tunicata.Here, we review some genome-level features of mtDNA, such as genetic code, gene content, genome architecture and gene strand asymmetry, mostly focusing on differences existing between tunicates and remaining chordates. Indeed, tunicate mtDNAs show a surprisingly high variability in several genome-level features, even though the current tunicate taxon sampling is absolutely insufficient and is focused mainly on the class Ascidiacea. On the contrary, a stabilization of the mtDNA structural and evolutionary features is observed in both cephalochordates and vertebrates, where genome-level features are almost invariant. Thus, different evolutionary dynamics, probably related to divergent functional constraints, have modelled the overall mtDNA structure and organization of the three chordate subphyla.

  11. Characterization and metal-induced gene transcription of two new copper zinc superoxide dismutases in the solitary ascidian Ciona intestinalis

    Energy Technology Data Exchange (ETDEWEB)

    Ferro, Diana [Department of Biology, University of Padova, Padova (Italy); Institute for Evolution and Biodiversity, Westfälische Wilhelms-Universität, Münster (Germany); Franchi, Nicola [Department of Biology, University of Padova, Padova (Italy); Department of Biological, Chemical, Pharmaceutical Science and Technology, University of Palermo, Palermo (Italy); Mangano, Valentina [Department of Biological, Chemical, Pharmaceutical Science and Technology, University of Palermo, Palermo (Italy); Bakiu, Rigers [Department of Crop Production, Agricultural University of Tirana, Tirana (Albania); Cammarata, Matteo; Parrinello, Nicolò [Department of Biological, Chemical, Pharmaceutical Science and Technology, University of Palermo, Palermo (Italy); Santovito, Gianfranco, E-mail: gianfranco.santovito@unipd.it [Department of Biology, University of Padova, Padova (Italy); Ballarin, Loriano [Department of Biology, University of Padova, Padova (Italy)

    2013-09-15

    Highlights: •Ciona intestinalis express two copper-zinc superoxide dismutases (Cu,Zn SODs), one extracellular (Ci-SODa) and one intracellular isoform (Ci-SODb). •Promoters contain consensus sequences similar to mammalian MRE. •Metal exposure results in a significant increase of gene transcription: ci-soda is induced especially by copper and zinc, the increase of ci-sodb transcription is more evident after cadmium exposure. •Genes are mostly transcribed in circulating hemocytes and in ovarian follicular cells. -- Abstract: Antioxidant enzymes are known to protect living organisms against the oxidative stress risk, also induced by metals. In the present study, we describe the purification and molecular characterization of two Cu,Zn superoxide dismutases (SODs), referred to as Ci-SODa and Ci-SODb, from Ciona intestinalis, a basal chordate widely distributed in temperate shallow seawater. The putative amino acid sequences were compared with Cu,Zn SODs from other metazoans and phylogenetic analyses indicate that the two putative Ci-SODs are more related to invertebrate SODs than vertebrate ones. Both phylogenetic and preliminary homology modeling analyses suggest that Ci-SODa and Ci-SODb are extracellular and intracellular isoform, respectively. The mRNA of the two Cu,Zn SODs was localized in hemocytes and in ovarian follicular cells, as revealed by in situ hybridization. The time course of SOD mRNA levels in the presence of three different metals showed upregulation of ci-soda and inhibition of ci-sodb. Spectrophotometric analysis confirms the presence of SOD activity in Ciona tissues. Our in silico analyses of the ci-soda promoter region revealed putative consensus sequences similar to mammalian metal-responsive elements (MRE), suggesting that the transcription of these genes directly depends on metals. These data emphasize the importance of complex metal regulation of ci-soda and ci-sodb transcription, as components of an efficient detoxification pathway allowing the survival of C. intestinalis in continued, elevated presence of metals in the environment.

  12. Epibiosis of oxygen phototrophs containing chlorophylls a, b, c, and d on the colonial ascidian Cystodytes dellechiajei

    Czech Academy of Sciences Publication Activity Database

    Martínez-García, M.; Koblížek, Michal; López-Legentil, S.; Antón, J.

    2011-01-01

    Roč. 61, č. 1 (2011), s. 13-19. ISSN 0095-3628 Institutional research plan: CEZ:AV0Z50200510 Keywords : D-PRODUCING CYANOBACTERIUM * ACARYOCHLORIS-MARINA * ADAPTATION Subject RIV: EE - Microbiology, Virology Impact factor: 2.912, year: 2011

  13. Characterization and metal-induced gene transcription of two new copper zinc superoxide dismutases in the solitary ascidian Ciona intestinalis

    International Nuclear Information System (INIS)

    Highlights: •Ciona intestinalis express two copper-zinc superoxide dismutases (Cu,Zn SODs), one extracellular (Ci-SODa) and one intracellular isoform (Ci-SODb). •Promoters contain consensus sequences similar to mammalian MRE. •Metal exposure results in a significant increase of gene transcription: ci-soda is induced especially by copper and zinc, the increase of ci-sodb transcription is more evident after cadmium exposure. •Genes are mostly transcribed in circulating hemocytes and in ovarian follicular cells. -- Abstract: Antioxidant enzymes are known to protect living organisms against the oxidative stress risk, also induced by metals. In the present study, we describe the purification and molecular characterization of two Cu,Zn superoxide dismutases (SODs), referred to as Ci-SODa and Ci-SODb, from Ciona intestinalis, a basal chordate widely distributed in temperate shallow seawater. The putative amino acid sequences were compared with Cu,Zn SODs from other metazoans and phylogenetic analyses indicate that the two putative Ci-SODs are more related to invertebrate SODs than vertebrate ones. Both phylogenetic and preliminary homology modeling analyses suggest that Ci-SODa and Ci-SODb are extracellular and intracellular isoform, respectively. The mRNA of the two Cu,Zn SODs was localized in hemocytes and in ovarian follicular cells, as revealed by in situ hybridization. The time course of SOD mRNA levels in the presence of three different metals showed upregulation of ci-soda and inhibition of ci-sodb. Spectrophotometric analysis confirms the presence of SOD activity in Ciona tissues. Our in silico analyses of the ci-soda promoter region revealed putative consensus sequences similar to mammalian metal-responsive elements (MRE), suggesting that the transcription of these genes directly depends on metals. These data emphasize the importance of complex metal regulation of ci-soda and ci-sodb transcription, as components of an efficient detoxification pathway allowing the survival of C. intestinalis in continued, elevated presence of metals in the environment

  14. Increased Inter-Colony Fusion Rates Are Associated with Reduced COI Haplotype Diversity in an Invasive Colonial Ascidian Didemnum vexillum

    OpenAIRE

    Smith, Kirsty F.; Stefaniak, Lauren; Saito, Yasunori; Gemmill, Chrissen E.C.; Cary, S. Craig; Fidler, Andrew E.

    2012-01-01

    Considerable progress in our understanding of the population genetic changes associated with biological invasions has been made over the past decade. Using selectively neutral loci, it has been established that reductions in genetic diversity, reflecting founder effects, have occurred during the establishment of some invasive populations. However, some colonial organisms may actually gain an ecological advantage from reduced genetic diversity because of the associated reduction in inter-colon...

  15. Endozoicomonas are specific, facultative symbionts of sea squirts

    DEFF Research Database (Denmark)

    Schreiber, Lars; Kjeldsen, Kasper Urup; Funch, Peter;

    2016-01-01

    Ascidians are marine filter feeders and harbor diverse microbiota that can exhibit a high degree of host-specificity. Pharyngeal samples of Scandinavian and Mediterranean ascidians were screened for consistently associated bacteria by culture-dependent and -independent approaches. Representatives...

  16. Evolutionary changes in the notochord genetic toolkit: a comparative analysis of notochord genes in the ascidian Ciona and the larvacean Oikopleura

    Directory of Open Access Journals (Sweden)

    Jiang Di

    2011-01-01

    Full Text Available Abstract Background The notochord is a defining feature of the chordate clade, and invertebrate chordates, such as tunicates, are uniquely suited for studies of this structure. Here we used a well-characterized set of 50 notochord genes known to be targets of the notochord-specific Brachyury transcription factor in one tunicate, Ciona intestinalis (Class Ascidiacea, to begin determining whether the same genetic toolkit is employed to build the notochord in another tunicate, Oikopleura dioica (Class Larvacea. We identified Oikopleura orthologs of the Ciona notochord genes, as well as lineage-specific duplicates for which we determined the phylogenetic relationships with related genes from other chordates, and we analyzed their expression patterns in Oikopleura embryos. Results Of the 50 Ciona notochord genes that were used as a reference, only 26 had clearly identifiable orthologs in Oikopleura. Two of these conserved genes appeared to have undergone Oikopleura- and/or tunicate-specific duplications, and one was present in three copies in Oikopleura, thus bringing the number of genes to test to 30. We were able to clone and test 28 of these genes. Thirteen of the 28 Oikopleura orthologs of Ciona notochord genes showed clear expression in all or in part of the Oikopleura notochord, seven were diffusely expressed throughout the tail, six were expressed in tissues other than the notochord, while two probes did not provide a detectable signal at any of the stages analyzed. One of the notochord genes identified, Oikopleura netrin, was found to be unevenly expressed in notochord cells, in a pattern reminiscent of that previously observed for one of the Oikopleura Hox genes. Conclusions A surprisingly high number of Ciona notochord genes do not have apparent counterparts in Oikopleura, and only a fraction of the evolutionarily conserved genes show clear notochord expression. This suggests that Ciona and Oikopleura, despite the morphological similarities of their notochords, have developed rather divergent sets of notochord genes after their split from a common tunicate ancestor. This study demonstrates that comparisons between divergent tunicates can lead to insights into the basic complement of genes sufficient for notochord development, and elucidate the constraints that control its composition.

  17. Molecular orbital calculations, experimental and theoretical UV spectra of granulatimides and didemnimides, biologically active polycyclic heteroaromatic alkaloids from the ascidian Didemnum granulatum

    Science.gov (United States)

    Camargo, A. J.; Oliveira, J. H. H. L.; Trsic, M.; Berlinck, R. G. S.

    2001-01-01

    A detailed computational study was performed for compounds granulatimide, isogranulatimide, and didemnimides A, D, and E, using the semiempirical Austin model 1 quantum chemical method. The electronic features and structural parameters were confronted with the inhibition of the G2 cell cycle checkpoint of mammalian cancer cells. All compounds were submitted to a rigorous conformational analysis using the Tripos 5.2 force field implemented in the Spartan 5.01 program. The electronic density in specific regions of the molecules appears to play a pivotal role towards activity. The molecular planarity creates a broad negative electrostatic potential on the two sides of the active compounds (granulatimide and isogralulatimide) and a positive potential in their central core, while the non-planar compounds (didemnimides A, D, and E, which are inactive) present an asymmetric potential scattered over the molecules. These electrostatic potential features are likely to be the modulator of hydrophobicity or lipophilicity of the compounds, which appear correlated with activity. The hydrogen attached to the N atom of the pyrrole moiety of indole is more positive for active compounds than for the inactive molecules. The theoretical electronic spectra were obtained for all compounds using the configuration interaction method, with the AM1 routine. All transitions present π→π ∗ nature. The theoretical results are in good agreement with experimental values.

  18. Ascídias (Tunicata, Ascidiacea introduzidas no Arquipélago de Alcatrazes, São Paulo Introduced ascidians (Tunicata, Ascidiacea in the Arquipélago de Alcatrazes, State of São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Rosana M. da Rocha

    2009-03-01

    Full Text Available O Arquipélago de Alcatrazes (24º06'S, 45º42'W localiza-se a 36 km da costa e constitui uma Estação Ecológica desde 1987. Estando próximo à região portuária de São Sebastião, São Paulo, está sujeito à introdução de espécies exóticas. Com o objetivo de detectar se está ocorrendo ou não introdução de espécies, foram coletados 40 exemplares de ascídias da principal ilha do arquipélago, a Ilha de Alcatrazes, sendo 15 amostras da Baía do Oratório e 25 do Saco do Funil. Foram encontradas 24 espécies em sete famílias. Dentre estas, apenas cinco espécies podem ser consideradas como nativas para o Atlântico; quatro são atlânticas, mas criptogênicas na região devido à distribuição disjunta; cinco são classificadas como criptogênicas de ampla distribuição mundial; e uma pode ser considerada como um caso certo de introdução, Ciona intestinalis (Linnaeus, 1767. Há ainda nove espécies que não puderam ser identificadas, podendo algumas se tratar de espécies novas. A presença de uma espécie exótica e a grande quantidade de espécies criptogênicas com forte evidência de introdução são indícios de que as ilhas estão sendo ameaçadas por uma fauna não nativa. A conservação do Arquipélago deve levar em consideração a presença do porto como fonte de estresse e o controle das espécies introduzidas como parte do plano de manejo da Unidade de Conservação.Arquipélago de Alcatrazes (24º06'S, 45º42'W is 36 km off the coast and it is an Ecological Station since 1987. It is also located near the port region of São Sebastião, São Paulo, hence subjected to introduction of exotic species. Forty samples were taken in the principal island of the archipelago to detect possible introductions. Fifteen samples were from Baía do Oratório and 25 from Saco do Funil. Twenty four species distributed in seven families were found. Only five of them were classified as native, four are Atlantic but cryptogenic in the region because of the disjunct distribution; five are cryptogenic with world wide distribution; and one is a certain introduction, Ciona intestinalis (Linnaeus, 1767. There are other nine species that were not identified, a few of them possibly new species. The presence of one introduced species and the high number of cryptogenic species with strong evidence of introduction indicate that the islands are threatened by non-native fauna. The conservation of the Archipelago demands consideration of the port as one source of stress and the control of exotic species as an important aspect of the management procedures.

  19. Endozoicomonas Are Specific, Facultative Symbionts of Sea Squirts

    Science.gov (United States)

    Schreiber, Lars; Kjeldsen, Kasper U.; Funch, Peter; Jensen, Jeppe; Obst, Matthias; López-Legentil, Susanna; Schramm, Andreas

    2016-01-01

    Ascidians are marine filter feeders and harbor diverse microbiota that can exhibit a high degree of host-specificity. Pharyngeal samples of Scandinavian and Mediterranean ascidians were screened for consistently associated bacteria by culture-dependent and -independent approaches. Representatives of the Endozoicomonas (Gammaproteobacteria, Hahellaceae) clade were detected in the ascidian species Ascidiella aspersa, Ascidiella scabra, Botryllus schlosseri, Ciona intestinalis, Styela clava, and multiple Ascidia/Ascidiella spp. In total, Endozoicomonas was detected in more than half of all specimens screened, and in 25–100% of the specimens for each species. The retrieved Endozoicomonas 16S rRNA gene sequences formed an ascidian-specific subclade, whose members were detected by fluorescence in situ hybridization (FISH) as extracellular microcolonies in the pharynx. Two strains of the ascidian-specific Endozoicomonas subclade were isolated in pure culture and characterized. Both strains are chemoorganoheterotrophs and grow on mucin (a mucus glycoprotein). The strains tested negative for cytotoxic or antibacterial activity. Based on these observations, we propose ascidian-associated Endozoicomonas to be commensals, living off the mucus continuously secreted into the pharynx. Members of the ascidian-specific Endozoicomonas subclade were also detected in seawater from the Scandinavian sampling site, which suggests acquisition of the symbionts by horizontal transmission. The combined results indicate a host-specific, yet facultative symbiosis between ascidians and Endozoicomonas. PMID:27462299

  20. Macrofouling community structure in Kanayama Bay, Kii Peninsula (Japan)

    Digital Repository Service at National Institute of Oceanography (India)

    Raveendran, T.V.; Harada, E.

    of fouling organisms were monitored at monthly intervals. Fortnightly variations in hydrographic parameters were also noted simultaneously. The fouling community at this bay was a complex assemblage of bryozoans, ascidians, polychaetes and barnacles...

  1. Impact of predation by Ostracion immaculatus (Pisces: Ostraciidae) on the macrofouling community structure in Kanayama Bay, Kii Peninsula (Japan)

    Digital Repository Service at National Institute of Oceanography (India)

    Raveendran, T.V.; Harada, E.

    using predator inclusion as well as exclusion treatment confirmed that predation by this fish had significant impact on the structure of fouling community. The importance of predation was manifested mainly through the influence of fish on ascidians...

  2. Larvae of fouling organisms and macrofouling at New Mangalore Port, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Khandeparker, D.C.; Anil, A.C.; Venkat, K.

    Polychaetes, bryozoans, barnacles and ascidians were the dominant groups in the fouling community at New Mangalore Port. Polychaete and cirripede larvae were encountered throughout the year. Even though bivalve were present in the planktonic hauls...

  3. How Fast Is the Sessile Ciona?

    OpenAIRE

    Giuseppe D'Onofrio; Fernando Alvarez-Valin; Luisa Berná

    2009-01-01

    Genomewide analyses of distances between orthologous gene pairs from the ascidian species Ciona intestinalis and Ciona savignyi were compared with those of vertebrates. Combining this data with a detailed and careful use of vertebrate fossil records, we estimated the time of divergence between the two ascidians nearly 180 My. This estimation was obtained after correcting for the different substitution rates found comparing several groups of chordates; indeed we determine here that on average ...

  4. rRNA genes from the lower chordate Herdmania momus: structural similarity with higher eukaryotes.

    OpenAIRE

    Degnan, B M; Yan, J.; Hawkins, C J; Lavin, M F

    1990-01-01

    Ascidians, primitive chordates that have retained features of the likely progenitors to all vertebrates, are a useful model to study the evolutionary relationship of chordates to other animals. We have selected the well characterized ribosomal RNA (rRNA) genes to investigate this relationship, and we describe here the cloning and characterization of an entire ribosomal DNA (rDNA) tandem repeat unit from a lower chordate, the ascidian Herdmania momus. rDNA copy number and considerable sequence...

  5. Ascidia subterranea sp. nov. (Phlebobranchia: Ascidiidae), a new tunicate belonging to the A. sydneiensis Stimpson, 1855 group, found as burrow associate of Axiopsis serratifrons A. Milne-Edwards, 1873 (Decapoda: Axiidae) on Derawan Island, Indonesia.

    Science.gov (United States)

    Kneer, Dominik; Monniot, Francoise; Stach, Thomas; Christianen, Marjolijn J A

    2013-01-01

    A new tunicate, Ascidia subterranea sp. nov., was found in burrows of the axiid crustacean Axiopsis serratifrons on Derawan Island, Indonesia. It differs from other ascidians in its habitat as well as numerous morphological peculiarities which are described in detail. The shrimp Rostronia stylirostris Holthuis, 1952 was found inside A. subterranea sp. nov., and 4 species of bivalves, 3 species of polychaetes, 1 gastropod, 1 polyplacophoran and 1 sponge species were found as burrow associates besides the ascidian. PMID:24758824

  6. Territoriality and Conflict Avoidance Explain Asociality (Solitariness) of the Endosymbiotic Pea Crab Tunicotheres moseri

    OpenAIRE

    Ambrosio, Louis J.; Baeza, J. Antonio

    2016-01-01

    Host monopolization theory predicts symbiotic organisms inhabiting morphologically simple, relatively small and scarce hosts to live solitarily as a result of territorial behaviors. We tested this prediction with Tunicotheres moseri, an endosymbiotic crab dwelling in the atrial chamber of the morphologically simple, small, and relatively scarce ascidian Styela plicata. As predicted, natural populations of T. moseri inhabit ascidian hosts solitarily with greater frequency than expected by chan...

  7. Effects of freeze drying and silver staining on carbonization of cellulose: carbon nano-materials

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae-Young; Im, Hyun Sik [Dongguk University, Seoul (Korea, Republic of)

    2012-05-15

    We investigated the effects of sulfuric acid and silver particles on the carbonization of natural cellulose from Halocynthia. We carried out thermogravimetry and used transmission electron microscopy measurements to study the yield of carbon and the structure of the carbonized nano-fiber. We found that the addition of sulfuric acid and silver particles to the cellulose fiber enhanced the yield of carbon while keeping the original structure of the carbon nano-fiber.

  8. Isolamento e atividades biológicas de produtos naturais das esponjas monanchora arbuscula, aplysina sp. petromica ciocalyptoides e topsentia ophiraphidites, da ascídia didemnum ligulum e do octocoral carijoa riisei Isolantion and biological activities of secondary metabolites from the sponges monanchora aff. arbuscula, aplysina sp. petromica ciocalyptoides and topsentia ophiraphidies, from the ascidian didemnum ligulum and from the octocoral carijoa riisei

    OpenAIRE

    Miriam H. Kossuga; Simone P. de Lira; Andréa M. Nascimento; Gambardella, Maria Teresa P.; Berlinck, Roberto G. S.; Yohandra R. Torres; Gislene G. F. Nascimento; Eli F. Pimenta; Marcio Silva; Otávio H. Thiemann; Glaucius Oliva; André G. Tempone; Melhem, Márcia S.C.; Ana O. de Souza; Galetti, Fabio C. S.

    2007-01-01

    The investigation of extracts from six species of marine invertebrates yielded one new and several known natural products. Isoptilocaulin from the sponge Monanchora aff. arbuscula displayed antimicrobial activity at 1.3 mg/mL against an oxacillin-resistant strain of Staphylococcus aureus. Five inactive known dibromotyrosine derivatives, 2 6, were isolated from a new species of marine sponge, Aplysina sp. The sponges Petromica ciocalyptoides and Topsentia ophiraphidites yielded the known halis...

  9. A novel third complement component C3 gene of Ciona intestinalis expressed in the endoderm at the early developmental stages

    OpenAIRE

    Hibino, T.; Nonaka, M

    2013-01-01

    The third complement component (C3) in ascidian was reported to function as an opsonin to enhance phagocytosis and as a chemotactic factor for phagocytes, indicating that ascidian C3 works in mesodermal cavity as a humoral factor like vertebrate C3s. In the basal Eumetazoa, Cnidaria lacking mesodermal tissues, C3 was reported to work in an endodermal cavity. Evolution of structure and function of C3 is still to be clarified. Here we report the identification of the third C3 gene, CiC3-3, in t...

  10. How Fast Is the Sessile Ciona?

    Directory of Open Access Journals (Sweden)

    Luisa Berná

    2009-01-01

    Full Text Available Genomewide analyses of distances between orthologous gene pairs from the ascidian species Ciona intestinalis and Ciona savignyi were compared with those of vertebrates. Combining this data with a detailed and careful use of vertebrate fossil records, we estimated the time of divergence between the two ascidians nearly 180 My. This estimation was obtained after correcting for the different substitution rates found comparing several groups of chordates; indeed we determine here that on average Ciona species evolve 50% faster than vertebrates.

  11. Isolation of C11 Cyclopentenones from Two Didemnid Species, Lissoclinum sp. and Diplosoma sp.

    Directory of Open Access Journals (Sweden)

    Katsuhiro Ueda

    2009-12-01

    Full Text Available A series of new C11 cyclopentenones 1-7 was isolated, together with four known metabolites 9/10, 12 and 13, from the extract of the didemnid ascidian Lissoclinum sp. The other didemnid ascidian Diplosoma sp. contained didemnenones 1, 2 and 5, and five known metabolites 8-12. The structures of 1-7 were elucidated by spectroscopic analyses. Cytotoxicity of the isolated compounds was evaluated against three human cancer cell lines (HCT116, A431 and A549.

  12. Dicty_cDB: SSL245 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available ) acidic repetitive protein arp1 - Tetrahymena ther... 35 0.63 AB276041_1( AB276041 |pid:none) Halocynthia ...lus adult male tongue cDNA, partial sequence, clone 2300004K05. 34 0.27 2 BH91162...X-263J20 on chromosome 7 Contains a gene for a novel kinase with a CNH domain, one complete and part of five... genes for novel proteins similar to novel immune-type receptors (nitr), a novel gene similar to nitr4 and par...nts: (bits) Value AL844508_198( AL844508 |pid:none) Plasmodium falciparum 3D7 chr

  13. Biophysical characterization of the fluorescent protein voltage probe VSFP2.3 based on the voltage-sensing domain of Ci-VSP

    DEFF Research Database (Denmark)

    Lundby, Alicia; Akemann, Walther; Knöpfel, Thomas

    2010-01-01

    A voltage sensitive phosphatase was discovered in the ascidian Ciona intestinalis. The phosphatase, Ci-VSP, contains a voltage-sensing domain homologous to those known from voltage-gated ion channels, but unlike ion channels, the voltage-sensing domain of Ci-VSP can reside in the cell membrane as...

  14. Particle-capture mechanisms in suspension-feeding invertebrates

    DEFF Research Database (Denmark)

    Riisgård, Hans Ulrik; Larsen, Poul Scheel

    2010-01-01

    A large number of suspension-feeding animals (e.g. bivalves, polychaetes, ascidians, bryozoans, crustaceans, sponges, echinoderms, cnidarians) have specialized in grazing on not only the 2 to 200 µm phytoplankton but frequently also the 0.5 to 2 µm free-living bacteria in the aquatic environment,...

  15. How the sea squirt nucleus tells mesoderm Not to be endoderm

    OpenAIRE

    Parton, Richard M.; Davis, Ilan

    2010-01-01

    Sea squirts are simple invertebrate chordates. In this issue, Takatori et al show nuclear migration within ascidian mesendodermal cells enables polarized localization of Not mRNA, which encodes a homeobox protein that distinguishes mesoderm from endoderm fates. The link between nuclear migration and mRNA localization suggests exciting parallels with protostomes.

  16. Biomixing generated by benthic filterfeeders: A diffusion model for near-bottom phytoplankton depletion

    DEFF Research Database (Denmark)

    Scheel Larsen, Poul; Riisgård, H.U.

    1997-01-01

    polychaete Nereis diversicolor and the ascidian Ciona intestinalis, respectively. The model is based on sinks located at inhalant openings and Fick's law with an effective diffusivity that decreases with distance above the bottom due to the biomixing generated by exhalant and inhalant feeding currents. For N...

  17. The cyclopoid copepod Pseudomyicola spinosus (Raffaele & Monticelli) from marine pelecypods, chiefly in Bermuda and the West Indies

    NARCIS (Netherlands)

    Humes, Arthur G.

    1968-01-01

    The myicolid copepod Pseudomyicola spinosus is reported from 22 new hosts (pelecypods) in Bermuda and the West Indies, from 1 new host (a pelecypod) in Madagascar, and from an ascidian (Pyuridae) in Curaçao (probably an accidental association). P. spinosus is redescribed, based on specimens from Iso

  18. Proximate composition of marine invertebrates from tropical coastal waters, with emphasis on the relationship between nitrogen and protein contents

    OpenAIRE

    Graciela S Diniz; Elisabete Barbarino; João Oiano-Neto; Sidney Pacheco; Sergio O. Lourenço

    2014-01-01

    The chemical profiles of Desmapsamma anchorata, Hymeniacidon heliophila (Porifera), Bunodosoma caissarum, Renilla muelleri (Cnidaria), Aplysia brasiliana, Eledone massyae, Isognomon bicolor (Mollusca), Echinaster brasiliensis, Echinometra lucunter, Holothuria grisea, Lytechinus variegatus (Echinodermata), and Phallusia nigra (Chordata) were determined. Hydrosoluble protein was the most abundant class of substances for all species, except for the ascidian Phallusia nigra, in which the carbohyd...

  19. A novel third complement component C3 gene of Ciona intestinalis expressed in the endoderm at the early developmental stages

    Directory of Open Access Journals (Sweden)

    T Hibino

    2013-04-01

    Full Text Available The third complement component (C3 in ascidian was reported to function as an opsonin to enhance phagocytosis and as a chemotactic factor for phagocytes, indicating that ascidian C3 works in mesodermal cavity as a humoral factor like vertebrate C3s. In the basal Eumetazoa, Cnidaria lacking mesodermal tissues, C3 was reported to work in an endodermal cavity. Evolution of structure and function of C3 is still to be clarified. Here we report the identification of the third C3 gene, CiC3-3, in the genome of an ascidian, Ciona intestinalis. Phylogenetic analysis using the entire amino acid sequences of Eumetazoan C3s indicated that CiC3-3 possess a closer relationship to vertebrate C3, C4 and C5 than other ascidian C3s. Although CiC3-3 retained the α-β processing site and 6 cysteine residues in the C3a region, it lacked the intra-molecular thioester bond and the catalytic histidine residue. Instead, CiC3-3 had a unique insertion of about 70 residues long Lys/Arg-rich sequence. CiC3-3 was expressed highly in the embryonic stages, but little in the adult in contradistinction to CiC3-1 and CiC3-2. The expression of CiC3-3 in early embryonic stages was restricted to endoderm similar to cnidarian C3s. Thus, the ascidian complement system could represent a unique evolutionary stage sharing a primitive endodermal function with Cnidaria, and newly developed humoral function with vertebrates.

  20. The mitochondrial genome of Phallusia mammillata and Phallusia fumigata (Tunicata, Ascidiacea: high genome plasticity at intra-genus level

    Directory of Open Access Journals (Sweden)

    Pesole Graziano

    2007-08-01

    Full Text Available Abstract Background Within Chordata, the subphyla Vertebrata and Cephalochordata (lancelets are characterized by a remarkable stability of the mitochondrial (mt genome, with constancy of gene content and almost invariant gene order, whereas the limited mitochondrial data on the subphylum Tunicata suggest frequent and extensive gene rearrangements, observed also within ascidians of the same genus. Results To confirm this evolutionary trend and to better understand the evolutionary dynamics of the mitochondrial genome in Tunicata Ascidiacea, we have sequenced and characterized the complete mt genome of two congeneric ascidian species, Phallusia mammillata and Phallusia fumigata (Phlebobranchiata, Ascidiidae. The two mtDNAs are surprisingly rearranged, both with respect to one another and relative to those of other tunicates and chordates, with gene rearrangements affecting both protein-coding and tRNA genes. The new data highlight the extraordinary variability of ascidian mt genome in base composition, tRNA secondary structure, tRNA gene content, and non-coding regions (number, size, sequence and location. Indeed, both Phallusia genomes lack the trnD gene, show loss/acquisition of DHU-arm in two tRNAs, and have a G+C content two-fold higher than other ascidians. Moreover, the mt genome of P. fumigata presents two identical copies of trnI, an extra tRNA gene with uncertain amino acid specificity, and four almost identical sequence regions. In addition, a truncated cytochrome b, lacking a C-terminal tail that commonly protrudes into the mt matrix, has been identified as a new mt feature probably shared by all tunicates. Conclusion The frequent occurrence of major gene order rearrangements in ascidians both at high taxonomic level and within the same genus makes this taxon an excellent model to study the mechanisms of gene rearrangement, and renders the mt genome an invaluable phylogenetic marker to investigate molecular biodiversity and speciation

  1. Structure and function of vanadium compounds in living organisms.

    Science.gov (United States)

    Rehder, D

    1992-01-01

    Vanadium has been recognized as a metal of biological importance only recently. In this mini-review, its main functions uncovered during the past few years are addressed. These encompass (i) the regulation of phosphate metabolizing enzymes (which is exemplified for the inhibition of ribonucleases by vanadate), (ii) the halogenation of organic compounds by vanadate-dependent non-heme peroxidases from seaweeds, (iii) the reductive protonation of nitrogen (nitrogen fixation) by alternative, i.e. vanadium-containing, nitrogenases from N2-fixing bacteria, (iv) vanadium sequestering by sea squirts (ascidians), and (v) amavadine, a low molecular weight complex of V(IV) accumulated in the fly agaric and related toadstools. The function of vanadium, while still illusive in ascidians and toadstools, begins to be understood in vanadium-enzyme interaction. Investigations into the structure and function of model compounds play an increasingly important role in elucidating the biological significance of vanadium. PMID:1392470

  2. Effects of simulated eutrophication and overfishing on algae and invertebrate settlement in a coral reef of Koh Phangan, Gulf of Thailand.

    Science.gov (United States)

    Stuhldreier, Ines; Bastian, Pepe; Schönig, Eike; Wild, Christian

    2015-03-15

    Coral reefs in the Gulf of Thailand are highly under-investigated regarding responses to anthropogenic stressors. Thus, this study simulated overfishing and eutrophication using herbivore exclosure cages and slow-release fertilizer to study the in-situ effects on benthic algae and invertebrate settlement in a coral reef of Koh Phangan, Thailand. Settlement of organisms and the development of organic matter on light-exposed and shaded tiles were quantified weekly/biweekly over a study period of 12 weeks. Simulated eutrophication did not significantly influence response parameters, while simulated overfishing positively affected dry mass, turf algae height and fleshy macroalgae occurrence on light-exposed tiles. On shaded tiles, settlement of crustose coralline algae decreased, while abundances of ascidians increased compared to controls. An interactive effect of both stressors was not observed. These results hint to herbivory as actual key controlling factor on the benthic community, and fleshy macroalgae together with ascidians as potential bioindicators for local overfishing. PMID:25649838

  3. Sialic acids as link to Japanese scientists.

    Science.gov (United States)

    Schauer, Roland

    2016-01-01

    This manuscript is dedicated to Prof. Tamio Yamakawa and describes my cooperations on sialic acid-related topics with Japanese scientists during the last 40 years. We studied sialic acids and their O-acetylated derivatives in the sea urchin Pseudocentrotus depressus, in Halocynthia species, and in human and bovine milk. In seafood we mainly searched for N-glycolylneuraminic acid. With synthetic substrates it was shown that sialic acid O-acetylation at C-4 hinders the activity of sialidases, with the exception of viral enzymes. The biosynthesis of Neu5Gc was discussed and the distribution of this sialic acid in dogs followed in modern literature and reviewed regarding their migration. An excellent source of sialic acids is edible bird nest substance (Collocalia mucin) which was used for the synthesis of sialylation inhibitors. PMID:27063181

  4. Dicty_cDB: Contig-U11432-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available RESS *** f... 54 0.022 1 ( CT354301 ) Sus scrofa genomic clone CH242-379O24, genomic...34_120( CP001334 |pid:none) Micromonas sp. RCC299 chromosome... 56 4e-06 AY540193_1( AY540193 |pid:none) Lyt...74_506( CP001574 |pid:none) Micromonas sp. RCC299 chromosome... 36 4.7 CP000716_860( CP000716 |pid:none) The...malized... 48 1.3 1 ( DV159675 ) KP1B.101B11F.050722T7 KP1B Nicotiana tabacum cDNA... 48 1.3 1 ( DB614365 ) Halocynthia ror... strain OTTH05... 202 2e-79 CU640366_1328( CU640366 |pid:none) Podospora anserina genomic DNA ... 204 7e-75

  5. Cyanobacterial Diversity and a New Acaryochloris-Like Symbiont from Bahamian Sea-Squirts

    OpenAIRE

    Susanna López-Legentil; Bongkeun Song; Manel Bosch; Joseph R Pawlik; Xavier Turon

    2011-01-01

    Symbiotic interactions between ascidians (sea-squirts) and microbes are poorly understood. Here we characterized the cyanobacteria in the tissues of 8 distinct didemnid taxa from shallow-water marine habitats in the Bahamas Islands by sequencing a fragment of the cyanobacterial 16S rRNA gene and the entire 16S-23S rRNA internal transcribed spacer region (ITS) and by examining symbiont morphology with transmission electron (TEM) and confocal microscopy (CM). As described previously for other s...

  6. Diversity of Nonribosomal Peptide Synthetase Genes in the Microbial Metagenomes of Marine Sponges

    OpenAIRE

    Ute Hentschel; Sheila Marie Pimentel-Elardo; Sebastian Proksch; Lubomir Grozdanov

    2012-01-01

    Genomic mining revealed one major nonribosomal peptide synthetase (NRPS) phylogenetic cluster in 12 marine sponge species, one ascidian, an actinobacterial isolate and seawater. Phylogenetic analysis predicts its taxonomic affiliation to the actinomycetes and hydroxy-phenyl-glycine as a likely substrate. Additionally, a phylogenetically distinct NRPS gene cluster was discovered in the microbial metagenome of the sponge Aplysina aerophoba, which shows ...

  7. Investigation of the potential anticancer and antifungal active secondary metabolites from marine natural products

    OpenAIRE

    Boonlarppradab, Chollaratt

    2007-01-01

    The oceans are a unique resource that has contributed greatly to the field of natural products chemistry. Secondary metabolites from natural sources still play an important role in drug discovery and development by providing pharmaceutical candidates with novel structures that are valuable for synthetic modification. Of the marine organisms described to date, the vast majority of marine natural products derive from invertebrates such as sponges, ascidians, bryozoans, and tunicates. Recently, ...

  8. Antimicrobial natural products from Arctic and sub-Arcticmarine invertebrates

    OpenAIRE

    Tadesse, Margey

    2010-01-01

    Infectious diseases are a leading cause of death world-wide and there is a growing need for new anti-infective agents to combat multi-resistant strains of bacteria and fungi. Marine natural products are promising sources of novel antimicrobial compounds. In the present thesis, an investigation into the antimicrobial metabolites of Arctic and sub-Arctic marine invertebrate species is presented. Extracts of seven ascidian species, six sponge species, a soft-alcyonid coral and a bryozoan species...

  9. Antibiotic, cytotoxic and enzyme inhibitory activity of crude extracts from Brazilian marine invertebrates Atividade antibiótica, citotóxica e de inibição enzimática de extratos brutos de invertebrados marinhos do Brasil

    OpenAIRE

    Mirna H.R. Seleghim; Simone P. Lira; Miriam H. Kossuga; Tatiana Batista; Roberto G. S. Berlinck; Eduardo Hajdu; Guilherme Muricy; Rosana M. da Rocha; Gislene G. F. do Nascimento; Marcio Silva; Eli F. Pimenta; Thiemann, Otávio H.; Glaucius Oliva; Bruno C. Cavalcanti; Claudia Pessoa

    2007-01-01

    Herein we present the results of a screening with 349 crude extracts of Brazilian marine sponges, ascidians, bryozoans and octocorals, against 16 strains of susceptible and antibiotic-resistant bacteria, one yeast (Candida albicans), Mycobacterium tuberculosis H37Rv, three cancer cell lines MCF-7 (breast), B16 (murine melanoma ) and HCT8 (colon), and Leishmania tarentolae adenine phosphoribosyl transferase (L-APRT) enzyme. Less than 15% of marine sponge crude extracts displayed antibacterial ...

  10. Cryptic speciation or global spread? The case of a cosmopolitan marine invertebrate with limited dispersal capabilities

    OpenAIRE

    Pérez-Portela, R.; Arranz, V.; Rius, Marc; Turon, Xavier

    2013-01-01

    The existence of globally-distributed species with low dispersal capabilities is a paradox that has been explained as a result of human-mediated transport and by hidden diversity in the form of unrecognized cryptic species. Both factors are not mutually exclusive, but relatively few studies have demonstrated the presence of both. Here we analyse the genetic patterns of the colonial ascidian Diplosoma listerianum, a species nowadays distributed globally. The study of a fragment of ...

  11. Ecología química en el bentos marino de la Antártida: productos naturales y defensa química en esponjas hexactinélidas, corales blandos y ascidias coloniales

    OpenAIRE

    Núñez Pons, Laura

    2012-01-01

    The inhabitants of marine benthos must combat the ecological pressure caused by predation, competition and fouling through a series of mechanisms, one of which is chemical defense. This type of protection is particularly extended among sessile and/or sluggish organisms, such as sponges, soft corals or ascidians. The strategies to prevent predation are related to bad taste rather than to toxicity. Moreover, they must be considered along with nutritional quality, since the more nutritious the p...

  12. Tunicates: exploring the sea shores and roaming the open ocean. A tribute to Thomas Huxley

    OpenAIRE

    Lemaire, Patrick; Piette, Jacques

    2015-01-01

    This review is a tribute to the remarkable contributions of Thomas Huxley to the biology of tunicates, the likely sister group of vertebrates. In 1851, the great biologist and philosopher published two landmark papers on pelagic tunicates in the Philosophical Transactions of the Royal Society. They were dedicated to the description of the adult anatomy and life cycle of thaliaceans and appendicularians, the pelagic relatives of ascidians. In the first part of this review, we discuss the novel...

  13. Conservation of Notochord Gene Expression Across Chordates: Insights From the Leprecan Gene Family

    OpenAIRE

    Capellini, Terence D.; Dunn, Matthew P.; Yale J Passamaneck; Selleri, Licia; Di Gregorio, Anna

    2008-01-01

    The notochord is a defining character of the chordates, and the T-box transcription factor Brachyury has been shown to be required for notochord development in all chordates examined. In the ascidian Ciona intestinalis, at least 44 notochord genes have been identified as bona fide transcriptional targets of Brachyury. We examined the embryonic expression of a subset of murine orthologs of Ciona Brachyury target genes in the notochord to assess its conservation throughout chordate evolution. W...

  14. Wnt affects symmetry and morphogenesis during post-embryonic development in colonial chordates

    OpenAIRE

    Di Maio, Alessandro; Setar, Leah; Tiozzo, Stefano; De Tomaso, Anthony W

    2015-01-01

    Background Wnt signaling is one of the earliest and most highly conserved regulatory pathways for the establishment of the body axes during regeneration and early development. In regeneration, body axes determination occurs independently of tissue rearrangement and early developmental cues. Modulation of the Wnt signaling in either process has shown to result in unusual body axis phenotypes. Botryllus schlosseri is a colonial ascidian that can regenerate its entire body through asexual buddin...

  15. Ciona intestinalis as an emerging model organism: its regeneration under controlled conditions and methodology for egg dechorionation*

    OpenAIRE

    Liu, Li-Ping; Xiang, Jian-hai; Dong, Bo; Natarajan, Pavanasam; Yu, Kui-jie; Cai, Nan-er

    2006-01-01

    The ascidian Ciona intestinalis is a model organism of developmental and evolutionary biology and may provide crucial clues concerning two fundamental matters, namely, how chordates originated from the putative deuterostome ancestor and how advanced chordates originated from the simplest chordates. In this paper, a whole-life-span culture of C. intestinalis was conducted. Fed with the diet combination of dry Spirulina, egg yolk, Dicrateria sp., edible yeast and weaning diet for shrimp, C. int...

  16. Ciona Genetics

    OpenAIRE

    Veeman, Michael T.; Chiba, Shota; Smith, William C.

    2011-01-01

    Ascidians, such as Ciona, are invertebrate chordates with simple embryonic body plans and small, relatively non-redundant genomes. Ciona genetics is in its infancy compared to many other model systems, but it provides a powerful method for studying this important vertebrate outgroup. Here we give basic methods for genetic analysis of Ciona, including protocols for controlled crosses both by natural spawning and by the surgical isolation of gametes; the identification and propagation of mutant...

  17. The identification of transcription factors expressed in the notochord of Ciona intestinalis adds new potential players to the Brachyury gene regulatory network

    OpenAIRE

    Diana S José-Edwards; Kerner, Pierre; Kugler, Jamie E.; Deng, Wei; Jiang, Di; Di Gregorio, Anna

    2011-01-01

    The notochord is the distinctive characteristic of chordates; however, the knowledge of the complement of transcription factors governing the development of this structure is still incomplete. Here we present the expression patterns of seven transcription factor genes detected in the notochord of the ascidian Ciona intestinalis at various stages of embryonic development. Four of these transcription factors, Fos-a, NFAT5, AFF and Klf15, have not been directly associated with the notochord in p...

  18. Prospective protochordate homologs of vertebrate midbrain and MHB, with some thoughts on MHB origins

    Directory of Open Access Journals (Sweden)

    Thurston C. Lacalli

    2006-01-01

    Full Text Available The MHB (midbrain-hindbrain boundary is a key organizing center in the vertebrate brain characterized by highly conserved patterns of gene expression. The evidence for an MHB homolog in protochordates is equivocal, the "neck" region immediately caudal to the sensory vesicle in ascidian larvae being the best accepted candidate. It is argued here that similarities in expression patterns between the MHB and the ascidian neck region are more likely due to the latter being the principal source of neurons in the adult brain, and hence where all the genes involved in patterning the latter will necessarily be expressed. The contrast with amphioxus is exemplified by pax2/5/8, expressed in the neck region in ascidian larvae, but more caudally, along much of the nerve cord in amphioxus. The zone of expression in each case corresponds with that part of the nerve cord ultimately responsible for innervating the adult body, which suggests the spatially restricted MHB-like expression pattern in ascidians is secondarily reduced from a condition more like that in amphioxus. Patterns resembling those of the vertebrate MHB are nevertheless found elsewhere among metazoans. This suggests that, irrespective of its modern function, the MHB marks the site of an organizing center of considerable antiquity. Any explanation for how such a center became incorporated into the chordate brain must take account of the dorsoventral inversion chordates have experienced relative to other metazoans. Especially relevant here is a concept developed by Claus Nielsen, in which the brain is derived from a neural center located behind the ancestral mouth. While this is somewhat counterintuitive, it accords well with emerging molecular data.

  19. Ciona intestinalis as an emerging model organism: its regeneration under controlled conditions and methodology for egg dechorionation

    Institute of Scientific and Technical Information of China (English)

    LIU Li-ping; XIANG Jian-hai; DONG Bo; NATARAJAN Pavanasam; YU Kui-jie; CAI Nan-er

    2006-01-01

    The ascidian Ciona intestinalis is a model organism of developmental and evolutionary biology and may provide crucial clues concerning two fundamental matters, namely, how chordates originated from the putative deuterostome ancestor and how advanced chordates originated from the simplest chordates. In this paper, a whole-life-span culture of C. intestinalis was conducted. Fed with the diet combination of dry Spirulina, egg yolk, Dicrateria sp., edible yeast and weaning diet for shrimp, C.intestinalis grew up to average 59 mm and matured after 60 d cultivation. This culture process could be repeated using the artificially cultured mature ascidians as material. When the fertilized eggs were maintained under 10, 15, 20, 25 ℃, they hatched within 30 h, 22 h, 16 h and 12 h 50 min respectively experiencing cleavage, blastulation, gastrulation, neurulation, tailbud stage and tadpole stage. The tadpole larvae were characterized as typical but simplified chordates because of their dorsal nerve cord, notochord and primordial brain. After 8~24 h freely swimming, the tadpole larvae settled on the substrates and metamorphosized within 1~2 d into filter feeding sessile juvenile ascidians. In addition, unfertilized eggs were successfully dechorionated in filtered seawater containing 1% Tripsin, 0.25% EDTA at pH of 10.5 within 40 min. After fertilization, the dechorionated eggs developed well and hatched at normal hatching rate. In conclusion, this paper presented feasible methodology for rearing the tadpole larvae of C. intestinalis into sexual maturity under controlled conditions and detailed observations on the embryogenesis of the laboratory cultured ascidians, which will facilitate developmental and genetic research using this model system.

  20. New genes in the evolution of the neural crest differentiation program

    OpenAIRE

    Martínez-Morales, Juan Ramón; Henrich, Thorsten; Ramialison, Mirana; Wittbrodt, Joachim

    2007-01-01

    BACKGROUND: Development of the vertebrate head depends on the multipotency and migratory behavior of neural crest derivatives. This cell population is considered a vertebrate innovation and, accordingly, chordate ancestors lacked neural crest counterparts. The identification of neural crest specification genes expressed in the neural plate of basal chordates, in addition to the discovery of pigmented migratory cells in ascidians, has challenged this hypothesis. These new findings revive th...

  1. Morphological Differences between Larvae of the Ciona intestinalis Species Complex: Hints for a Valid Taxonomic Definition of Distinct Species

    OpenAIRE

    Roberta Pennati; Gentile Francesco Ficetola; Riccardo Brunetti; Federico Caicci; Fabio Gasparini; Francesca Griggio; Atsuko Sato; Thomas Stach; Sabrina Kaul-Strehlow; Carmela Gissi; Lucia Manni

    2015-01-01

    The cosmopolitan ascidian Ciona intestinalis is the most common model species of Tunicata, the sister-group of Vertebrata, and widely used in developmental biology, genomics and evolutionary studies. Recently, molecular studies suggested the presence of cryptic species hidden within the C. intestinalis species, namely C. intestinalis type A and type B. So far, no substantial morphological differences have been identified between individuals belonging to the two types. Here we present morphome...

  2. Taxonomy, phylogeny, historical biogeography, and historical ecology of the genus Pontonia (Crustacea: Decapoda: Caridea: Palaemonidae)

    OpenAIRE

    Fransen, C.H.J.M.

    2002-01-01

    Species of the genus Pontonia Latreille, 1829, are distributed in tropical and subtropical waters around the world, living in association with either molluscan or ascidian hosts. In the present taxonomic revision, Pontonia sensu lato is divided into six genera: Pontonia sensu stricto; Ascidonia gen. nov., Rostronia gen. nov., Dactylonia gen. nov., Odontonia gen. nov., and Bruceonia gen. nov. A total of 29 species is described and figured, four of which are new to science: Pontonia pilosa spec...

  3. Phallusiasterol C, A New Disulfated Steroid from the Mediterranean Tunicate Phallusia fumigata

    Directory of Open Access Journals (Sweden)

    Concetta Imperatore

    2016-06-01

    Full Text Available A new sulfated sterol, phallusiasterol C (1, has been isolated from the Mediterranean ascidian Phallusia fumigata and its structure has been determined on the basis of extensive spectroscopic (mainly 2D NMR analysis. The possible role in regulating the pregnane X receptor (PXR activity of phallusiasterol C has been investigated; although the new sterol resulted inactive, this study adds more items to the knowledge of the structure-PXR regulating activity relationships in the case of sulfated steroids.

  4. Synthesis of fucosyl-containing glycoproteins of the vitelline coat in oocytes of Ciona intestinalis (Ascidia).

    OpenAIRE

    F.Rosati; Cotelli, F.; De Santis, R.; A. Monroy; Pinto, M. R.

    1982-01-01

    The sperm receptors of the ascidian oocyte are located at the outer surface of the vitelline coat (formerly called the chorion). The fucose residues are the receptor's most important components for sperm recognition and binding. We asked whether the fucosyl-containing glycoproteins of the vitelline coat are a product of the oocyte, the follicle cells, or the test cells. Ovaries of Ciona intestinalis were injected with L-[3H]fucose and the progress of its incorporation was followed by using au...

  5. Polycheria josephensis, a new species of symbiotic amphipod (Crustacea, Amphipoda, Dexaminidae) from the Northern Gulf of Mexico, with notes on its ecology

    OpenAIRE

    Foster, John; Thoma, Brent

    2016-01-01

    Polycheria josephensis sp. n. (Dexaminidae), an ascidian symbiont, is described from St. Joseph Bay, Florida and other locations in the Gulf of Mexico and the nearshore Atlantic Ocean from South Carolina to northern Florida. Observations on its ecology, behavior, and distribution are provided. Polycheria josephensis sp. n. is morphologically most similar to Polycheria osborni Calman, 1898 from the Pacific coast of North America. Polycheria josephensis sp. n. differs from P. osborni in the num...

  6. Cross-phylum functional equivalence of Otx genes and the origin of brain patterning

    OpenAIRE

    Adachi, Yoshitsugu

    2004-01-01

    Molecular mechanisms of cephalic development is an intriguing question in evolutionary and developmental biology. Otx gene plays important roles in animal brain and head development and Otx genes are found in all major animal groups: cnidarians, lophotrochozoans, ecdysozoans, anddeuterostomes. Ascidians, positioned near the origin of the phylum Chordata, share a conserved set of anteroposterior patterning genes withthat of vertebrates. Here I report the cross-phylum regulatory potential of th...

  7. In vivo antithrombotic properties of a heparin from the oocyte test cells of the sea squirt Styela plicata(Chordata-Tunicata)

    OpenAIRE

    L. Cardilo-Reis; M.C.M. Cavalcante; C.B.M. Silveira; M.S.G. Pavão

    2006-01-01

    In the ascidian Styela plicata, the oocytes are surrounded by two types of accessory cells named follicle cells and test cells. A heparin-like substance with an anticoagulant activity equivalent to 10% of mammalian heparin and about 5% as potent as the mammalian counterpart for the inhibition of thrombin by antithrombin was isolated from the oocyte test cells. In the present study, we compared the antithrombotic and hemorrhagic effects of sea squirt oocyte test cell heparin with those of porc...

  8. Water-borne sperm trigger vitellogenic egg growth in two sessile marine invertebrates.

    OpenAIRE

    Bishop, J D; Manríquez, P H; Hughes, R. N.

    2000-01-01

    A diverse array of sessile marine invertebrates mate by passive dispersal of sperm which fertilize the brooded eggs of neighbours. In two such species, a sea-mat (phylum Bryozoa) and an ascidian (phylum Chordata), vitellogenic egg growth is absent in reproductively isolated specimens, but is triggered by a water-borne factor released by conspecifics. In both of these colonial, hermaphroditic species, the active factor can be removed from water by filtration. The effect involves self-/non-self...

  9. Roseovarius sediminilitoris sp. nov., isolated from seashore sediment.

    Science.gov (United States)

    Park, Sooyeon; Yoon, Jung-Hoon

    2013-05-01

    A Gram-negative, motile and ovoid- to rod-shaped bacterial strain, designated M-M10(T), was isolated from a seashore sediment collected from the South Sea, South Korea. Strain M-M10(T) grew optimally at pH 7.0-8.0, at 30 °C and in the presence of 2 % (w/v) NaCl. The phylogenetic trees based on 16S rRNA gene sequences revealed that strain M-M10(T) clustered with the type strains of Roseovarius crassostreae, Roseovarius halocynthiae and Roseovarius marinus, with which it exhibited sequence similarities of 97.4, 97.3 and 95.1 %, respectively. It exhibited 93.2-95.1 % sequence similarity to the type strains of the other species of the genus Roseovarius. Strain M-M10(T) contained Q-10 as the predominant ubiquinone and C18 : 1ω7c and C16 : 0 as the major fatty acids, as observed in the genus Roseovarius. The polar lipid profile of strain M-M10(T) was similar to that of Roseovarius tolerans DSM 11457(T). The DNA G+C content of strain M-M10(T) was 63.0 mol% and its mean DNA-DNA relatedness values with Roseovarius crassostreae DSM 16950(T) and Roseovarius halocynthiae MA1-10(T) were 16 % and 22 %, respectively. Differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, demonstrated that strain M-M10(T) is distinct from other species of the genus Roseovarius. On the basis of the data presented, strain M-M10(T) is considered to represent a novel species of the genus Roseovarius, for which the name Roseovarius sediminilitoris sp. nov. is proposed. The type strain is M-M10(T) ( = KCTC 23959(T) = CCUG 62413(T)). PMID:22941298

  10. Territoriality and Conflict Avoidance Explain Asociality (Solitariness) of the Endosymbiotic Pea Crab Tunicotheres moseri.

    Science.gov (United States)

    Ambrosio, Louis J; Baeza, J Antonio

    2016-01-01

    Host monopolization theory predicts symbiotic organisms inhabiting morphologically simple, relatively small and scarce hosts to live solitarily as a result of territorial behaviors. We tested this prediction with Tunicotheres moseri, an endosymbiotic crab dwelling in the atrial chamber of the morphologically simple, small, and relatively scarce ascidian Styela plicata. As predicted, natural populations of T. moseri inhabit ascidian hosts solitarily with greater frequency than expected by chance alone. Furthermore, laboratory experiments demonstrated that intruder crabs take significantly longer to colonize previously infected compared to uninfected hosts, indicating as expected, that resident crabs exhibit monopolization behaviors. While territoriality does occur, agonistic behaviors employed by T. moseri do not mirror the overt behaviors commonly reported for other territorial crustaceans. Documented double and triple cohabitations in the field coupled with laboratory observations demonstrating the almost invariable success of intruder crabs colonizing occupied hosts, suggest that territoriality is ineffective in completely explaining the solitary social habit of this species. Additional experiments showed that T. moseri juveniles and adults, when searching for ascidians use chemical cues to avoid hosts occupied by conspecifics. This conspecific avoidance behavior reported herein is a novel strategy most likely employed to preemptively resolve costly territorial conflicts. In general, this study supports predictions central to host monopolization theory, but also implies that alternative behavioral strategies (i.e., conflict avoidance) may be more important than originally thought in explaining the host use pattern of symbiotic organisms. PMID:26910474

  11. The hemocytes of Polyandrocarpa mysakiensis: morphology and immune-related activities

    Directory of Open Access Journals (Sweden)

    L Ballarin

    2009-11-01

    Full Text Available A preliminary study of the hemocytes of developing buds of the compound ascidian Polyandrocarpa misakiensis was carried out at the light microscope level for a better understanding of their biological role. Similarly to other ascidians, P. misakiensis immunocytes are represented by phagocytes and morula cells. Phagocytes include hyaline amoebocytes and round, giant phagocytes, the former the probable precursors of the latter. Hyaline amoebocytes showed high macropinocytotic activity in the presence of bacteria, whereas yeast cells were ingested by phagocytosis. Morula cells contain the enzyme phenoloxidase inside their vacuoles, probably stored as pro-enzyme, which is released upon the recognition of non-self. Together with macrogranular leukocytes, morula cells were the most abundant hemocyte-types which stresses the importance of these cells in Polyandrocarpa biology. Macrogranular leukocytes are frequently found inside the vacuoles of phagocytes and were recognized by a polyclonal antibody raised against an opsonin purified from the colonial ascidian Botryllus schlosseri, which suggests that a similar lectin can be involved in the interaction between these cells and phagocytes.

  12. New Bioactive Alkyl Sulfates from Mediterranean Tunicates

    Directory of Open Access Journals (Sweden)

    Marialuisa Menna

    2012-10-01

    Full Text Available Chemical investigation of two species of marine ascidians, Aplidium elegans and Ciona edwardsii, collected in Mediterranean area, led to isolation of a series of alkyl sulfates (compounds 1–5 including three new molecules 1–3. Structures of the new metabolites have been elucidated by spectroscopic analysis. Based on previously reported cytotoxic activity of these type of molecules, compounds 1–3 have been tested for their effects on the growth of two cell lines, J774A.1 (BALB/c murine macrophages and C6 (rat glioma in vitro. Compounds 1 and 2 induced selective concentration-dependent mortality on J774A.1 cells.

  13. Ecology: a niche for cyanobacteria containing chlorophyll d

    DEFF Research Database (Denmark)

    Kühl, Michael; Chen, Min; Ralph, Peter J;

    2005-01-01

    The cyanobacterium known as Acaryochloris marina is a unique phototroph that uses chlorophyll d as its principal light-harvesting pigment instead of chlorophyll a, the form commonly found in plants, algae and other cyanobacteria; this means that it depends on far-red light for photosynthesis. Here...... we demonstrate photosynthetic activity in Acaryochloris-like phototrophs that live underneath minute coral-reef invertebrates (didemnid ascidians) in a shaded niche enriched in near-infrared light. This discovery clarifies how these cyanobacteria are able to thrive as free-living organisms...

  14. mRNA 5′-leader trans-splicing in the chordates

    OpenAIRE

    Vandenberghe, Amanda E.; Meedel, Thomas H.; Hastings, Kenneth E.M.

    2001-01-01

    We report the discovery of mRNA 5′-leader trans-splicing (SL trans-splicing) in the chordates. In the ascidian protochordate Ciona intestinalis, the mRNAs of at least seven genes undergo trans-splicing of a 16-nucleotide 5′-leader apparently derived from a 46-nucleotide RNA that shares features with previously characterized splice donor SL RNAs. SL trans-splicing was known previously to occur in several protist and metazoan phyla, however, this is the first report of SL trans-splicing within ...

  15. Recruitment Variability of Coral Reef Sessile Communities of the Far North Great Barrier Reef

    Science.gov (United States)

    Luter, Heidi M.; Duckworth, Alan R.; Wolff, Carsten W.; Evans-Illidge, Elizabeth; Whalan, Steve

    2016-01-01

    One of the key components in assessing marine sessile organism demography is determining recruitment patterns to benthic habitats. An analysis of serially deployed recruitment tiles across depth (6 and 12 m), seasons (summer and winter) and space (meters to kilometres) was used to quantify recruitment assemblage structure (abundance and percent cover) of corals, sponges, ascidians, algae and other sessile organisms from the northern sector of the Great Barrier Reef (GBR). Polychaetes were most abundant on recruitment titles, reaching almost 50% of total recruitment, yet covered Coral recruitment was very low, with coral reefs. PMID:27049650

  16. Evolution of developmental roles of Pax2/5/8 paralogs after independent duplication in urochordate and vertebrate lineages

    Directory of Open Access Journals (Sweden)

    Cañestro Cristian

    2008-08-01

    Full Text Available Abstract Background Gene duplication provides opportunities for lineage diversification and evolution of developmental novelties. Duplicated genes generally either disappear by accumulation of mutations (nonfunctionalization, or are preserved either by the origin of positively selected functions in one or both duplicates (neofunctionalization, or by the partitioning of original gene subfunctions between the duplicates (subfunctionalization. The Pax2/5/8 family of important developmental regulators has undergone parallel expansion among chordate groups. After the divergence of urochordate and vertebrate lineages, two rounds of independent gene duplications resulted in the Pax2, Pax5, and Pax8 genes of most vertebrates (the sister group of the urochordates, and an additional duplication provided the pax2a and pax2b duplicates in teleost fish. Separate from the vertebrate genome expansions, a duplication also created two Pax2/5/8 genes in the common ancestor of ascidian and larvacean urochordates. Results To better understand mechanisms underlying the evolution of duplicated genes, we investigated, in the larvacean urochordate Oikopleura dioica, the embryonic gene expression patterns of Pax2/5/8 paralogs. We compared the larvacean and ascidian expression patterns to infer modular subfunctions present in the single pre-duplication Pax2/5/8 gene of stem urochordates, and we compared vertebrate and urochordate expression to infer the suite of Pax2/5/8 gene subfunctions in the common ancestor of olfactores (vertebrates + urochordates. Expression pattern differences of larvacean and ascidian Pax2/5/8 orthologs in the endostyle, pharynx and hindgut suggest that some ancestral gene functions have been partitioned differently to the duplicates in the two urochordate lineages. Novel expression in the larvacean heart may have resulted from the neofunctionalization of a Pax2/5/8 gene in the urochordates. Expression of larvacean Pax2/5/8 in the endostyle, in

  17. DDBJ in the stream of various biological data

    OpenAIRE

    Miyazaki, S; Sugawara, H.; Ikeo, K.; Gojobori, T; Tateno, Y.

    2004-01-01

    In the past year we at DDBJ (http://www.ddbj.nig.ac.jp) have made a steady increase in the number of data submissions with a 50.6% increment in the number of bases or 46.5% increment in the number of entries. Among them the genome data of man, ascidian and rice hold the top three. Our activity has extended to providing a tool that enables sequence retrieval using regular expressions, and to launching our SOAP server and web services to facilitate the acquisition of proper data and tools from ...

  18. Cyanobacterial diversity and a new acaryochloris-like symbiont from Bahamian sea-squirts.

    Directory of Open Access Journals (Sweden)

    Susanna López-Legentil

    Full Text Available Symbiotic interactions between ascidians (sea-squirts and microbes are poorly understood. Here we characterized the cyanobacteria in the tissues of 8 distinct didemnid taxa from shallow-water marine habitats in the Bahamas Islands by sequencing a fragment of the cyanobacterial 16S rRNA gene and the entire 16S-23S rRNA internal transcribed spacer region (ITS and by examining symbiont morphology with transmission electron (TEM and confocal microscopy (CM. As described previously for other species, Trididemnum spp. mostly contained symbionts associated with the Prochloron-Synechocystis group. However, sequence analysis of the symbionts in Lissoclinum revealed two unique clades. The first contained a novel cyanobacterial clade, while the second clade was closely associated with Acaryochloris marina. CM revealed the presence of chlorophyll d (chl d and phycobiliproteins (PBPs within these symbiont cells, as is characteristic of Acaryochloris species. The presence of symbionts was also observed by TEM inside the tunic of both the adult and larvae of L. fragile, indicating vertical transmission to progeny. Based on molecular phylogenetic and microscopic analyses, Candidatus Acaryochloris bahamiensis nov. sp. is proposed for this symbiotic cyanobacterium. Our results support the hypothesis that photosymbiont communities in ascidians are structured by host phylogeny, but in some cases, also by sampling location.

  19. Structure and anticoagulant properties of sulfated glycosaminoglycans from primitive Chordates

    Directory of Open Access Journals (Sweden)

    PAVÃO MAURO S. G.

    2002-01-01

    Full Text Available Dermatan sulfates and heparin, similar to the mammalian glycosaminoglycans, but with differences in the degree and position of sulfation were previously isolated from the body of the ascidian Styela plicata and Ascidia nigra. These differences produce profound effects on their anticoagulant properties. S. plicata dermatan sulfate composed by 2-O-sulfatedalpha-L-iduronic acid and 4-O-sulfated N-acetyl-beta-D-galactosamine residues is a potent anticoagulant due to a high heparin cofactor II activity. Surprisingly, it has a lower potency to prevent thrombus formation on an experimental model and a lower bleeding effect in rats than the mammalian dermatan sulfate. In contrast, A. nigra dermatan sulfate, also enriched in 2-O-sulfated alpha-L-iduronic acid, but in this case sulfated at O-6 of the N-acetyl-beta-D-galactosamine units, has no in vitro or in vivo anticoagulant activity, does not prevent thrombus formation but shows a bleeding effect similar to the mammalian glycosaminoglycan. Ascidian heparin, composed by 2-O-sulfated alpha-L-iduronic acid, N- and 6-O-sulfated glucosamine (75% and alpha-L-iduronic acid, N- and 6-O-sulfated glucosamine (25% disaccharide units has an anticoagulant activity 10 times lower than the mammalian heparin, is about 20 times less potent in the inhibition of thrombin by antithrombin, but has the same heparin cofactor II activity as mammalian heparin.

  20. Natural variation of model mutant phenotypes in Ciona intestinalis.

    Directory of Open Access Journals (Sweden)

    Paolo Sordino

    Full Text Available BACKGROUND: The study of ascidians (Chordata, Tunicata has made a considerable contribution to our understanding of the origin and evolution of basal chordates. To provide further information to support forward genetics in Ciona intestinalis, we used a combination of natural variation and neutral population genetics as an approach for the systematic identification of new mutations. In addition to the significance of developmental variation for phenotype-driven studies, this approach can encompass important implications in evolutionary and population biology. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report a preliminary survey for naturally occurring mutations in three geographically interconnected populations of C. intestinalis. The influence of historical, geographical and environmental factors on the distribution of abnormal phenotypes was assessed by means of 12 microsatellites. We identified 37 possible mutant loci with stereotyped defects in embryonic development that segregate in a way typical of recessive alleles. Local populations were found to differ in genetic organization and frequency distribution of phenotypic classes. CONCLUSIONS/SIGNIFICANCE: Natural genetic polymorphism of C. intestinalis constitutes a valuable source of phenotypes for studying embryonic development in ascidians. Correlating genetic structure and the occurrence of abnormal phenotypes is a crucial focus for understanding the selective forces that shape natural finite populations, and may provide insights of great importance into the evolutionary mechanisms that generate animal diversity.

  1. Colony specificity in Botrylloides leachi. I. Morphological aspects

    Directory of Open Access Journals (Sweden)

    G Zaniolo

    2006-12-01

    Full Text Available We studied colony specificity in the colonial ascidian Botrylloides leachi which, as in other botryllid ascidians, leads to either fusion or non-fusion between contacting colonies. Fusion requires the prior disappearance of contacting tunic cuticles and contact between facing ampullar epithelia. The epithelial cells of the ampullar tip show “pad regions” rich in ribosomes, which contribute to the synthesis of new tunic and cuticle. Blood cells, mainly phagocytes and pigment cells, increase their concentrations inside the ampullar lumen and phagocytes can cross the ampullar epithelium and enter the tunic, where they can contribute to the digestion of tunic cuticles and cells of the ampullar epithelium in order to establish a common circulation. Non-fusion reaction, as studied in the colony allorecognition assay, resembles the subcuticular rejection described in Japanese Botrylloides, characterised by limited tunic fusion, hemocyte leakage, and necrotic spots. Conversely, in the cut surface assay, a more intense cytotoxic reaction is observed along the contact border. In this case, morula cells crowd massively inside the facing ampullae, enter the tunic, and release their vacuolar contents which are probably required for the formation of necrotic spots.

  2. High quality draft genome sequence of the slightly halophilic bacterium Halomonas zhanjiangensis type strain JSM 078169(T) (DSM 21076(T)) from a sea urchin in southern China.

    Science.gov (United States)

    Zhou, Yu; Li, Rui; Gao, Xiao-Yang; Lapidus, Alla; Han, James; Haynes, Matthew; Lobos, Elizabeth; Huntemann, Marcel; Pati, Amrita; Ivanova, Natalia N; Rohde, Manfred; Mavromatis, Konstantinos; Tindall, Brian J; Markowitz, Victor; Woyke, Tanja; Klenk, Hans-Peter; Kyrpides, Nikos C; Li, Wen-Jun

    2014-06-15

    Halomonas zhanjiangensis Chen et al. 2009 is a member of the genus Halomonas, family Halomonadaceae, class Gammaproteobacteria. Representatives of the genus Halomonas are a group of halophilic bacteria often isolated from salty environments. The type strain H. zhanjiangensis JSM 078169(T) was isolated from a sea urchin (Hemicentrotus pulcherrimus) collected from the South China Sea. The genome of strain JSM 078169(T) is the fourteenth sequenced genome in the genus Halomonas and the fifteenth in the family Halomonadaceae. The other thirteen genomes from the genus Halomonas are H. halocynthiae, H. venusta, H. alkaliphila, H. lutea, H. anticariensis, H. jeotgali, H. titanicae, H. desiderata, H. smyrnensis, H. salifodinae, H. boliviensis, H. elongata and H stevensii. Here, we describe the features of strain JSM 078169(T), together with the complete genome sequence and annotation from a culture of DSM 21076(T). The 4,060,520 bp long draft genome consists of 17 scaffolds with the 3,659 protein-coding and 80 RNA genes and is a part of Genomic Encyclopedia of Type Strains, Phase I: the one thousand microbial genomes (KMG) project. PMID:25197480

  3. Diversity of nonribosomal peptide synthetase genes in the microbial metagenomes of marine sponges.

    Science.gov (United States)

    Pimentel-Elardo, Sheila Marie; Grozdanov, Lubomir; Proksch, Sebastian; Hentschel, Ute

    2012-06-01

    Genomic mining revealed one major nonribosomal peptide synthetase (NRPS) phylogenetic cluster in 12 marine sponge species, one ascidian, an actinobacterial isolate and seawater. Phylogenetic analysis predicts its taxonomic affiliation to the actinomycetes and hydroxy-phenyl-glycine as a likely substrate. Additionally, a phylogenetically distinct NRPS gene cluster was discovered in the microbial metagenome of the sponge Aplysina aerophoba, which shows highest similarities to NRPS genes that were previously assigned, by ways of single cell genomics, to a Chloroflexi sponge symbiont. Genomic mining studies such as the one presented here for NRPS genes, contribute to on-going efforts to characterize the genomic potential of sponge-associated microbiota for secondary metabolite biosynthesis. PMID:22822366

  4. Results of environmental radioactivity surveys around the Onagawa Nuclear Power Station

    International Nuclear Information System (INIS)

    The results, i.e. nuclide analysis data, of environmental radioactivity surveys carried out around the Onagawa Nuclear Power Station of Tohoku Electric Power Co., Inc., from October, 1981, to December, 1982, are presented in tables; fallout, airborne dust, land water (source water for water service), soil, agricultural products (Japanese radish, rice), index plants (white Dutch clover, mugwort), seawater, sea-bottom deposit, fishes and shellfishes (rock trout, ear shell, ascidian, oyster), index marine products (gulfweed, edible seaweed, purplish Washington clan) seaweed (wakame seaweed) were examined. The Onagawa Nuclear Power Station is in the stage of construction at present, as of March, 1983, therefore, the data are for grasping the background levels in the areas concerned. For this same purpose, certain samples were also taken from other localities in Miyagi Prefecture. (Mori, K.)

  5. Cyanobactins from Cyanobacteria: Current Genetic and Chemical State of Knowledge

    Directory of Open Access Journals (Sweden)

    Joana Martins

    2015-11-01

    Full Text Available Cyanobacteria are considered to be one of the most promising sources of new, natural products. Apart from non-ribosomal peptides and polyketides, ribosomally synthesized and post-translationally modified peptides (RiPPs are one of the leading groups of bioactive compounds produced by cyanobacteria. Among these, cyanobactins have sparked attention due to their interesting bioactivities and for their potential to be prospective candidates in the development of drugs. It is assumed that the primary source of cyanobactins is cyanobacteria, although these compounds have also been isolated from marine animals such as ascidians, sponges and mollusks. The aim of this review is to update the current knowledge of cyanobactins, recognized as being produced by cyanobacteria, and to emphasize their genetic clusters and chemical structures as well as their bioactivities, ecological roles and biotechnological potential.

  6. Cyanobactins from Cyanobacteria: Current Genetic and Chemical State of Knowledge.

    Science.gov (United States)

    Martins, Joana; Vasconcelos, Vitor

    2015-11-01

    Cyanobacteria are considered to be one of the most promising sources of new, natural products. Apart from non-ribosomal peptides and polyketides, ribosomally synthesized and post-translationally modified peptides (RiPPs) are one of the leading groups of bioactive compounds produced by cyanobacteria. Among these, cyanobactins have sparked attention due to their interesting bioactivities and for their potential to be prospective candidates in the development of drugs. It is assumed that the primary source of cyanobactins is cyanobacteria, although these compounds have also been isolated from marine animals such as ascidians, sponges and mollusks. The aim of this review is to update the current knowledge of cyanobactins, recognized as being produced by cyanobacteria, and to emphasize their genetic clusters and chemical structures as well as their bioactivities, ecological roles and biotechnological potential. PMID:26580631

  7. Cryptic speciation or global spread? The case of a cosmopolitan marine invertebrate with limited dispersal capabilities.

    Science.gov (United States)

    R, Pérez-Portela; V, Arranz; M, Rius; X, Turon

    2013-01-01

    The existence of globally-distributed species with low dispersal capabilities is a paradox that has been explained as a result of human-mediated transport and by hidden diversity in the form of unrecognized cryptic species. Both factors are not mutually exclusive, but relatively few studies have demonstrated the presence of both. Here we analyse the genetic patterns of the colonial ascidian Diplosoma listerianum, a species nowadays distributed globally. The study of a fragment of a mitochondrial gene in localities worldwide revealed the existence of multiple cryptic species. In addition, we found a complex geographic structure and multiple clades occurred in sympatry. One of the species showed strong population structure irrespective of geographical distances, which is coherent with stochastic dispersal linked to human transport. The present study shows the complexity of discerning the role of cryptic diversity from human-driven range shifts worldwide, as well as disentangling the effects of natural and artificial dispersal. PMID:24217373

  8. Viscosity and not biological mechanisms often controls the effects of temperature on ciliary activity and swimming velocity of small aquatic organisms

    DEFF Research Database (Denmark)

    Larsen, Poul Scheel; Riisgård, H. U.

    2009-01-01

    A number of studies have shown that temperature-dependent viscosity of the ambient water controls or strongly affects bio-mechanical activity such as beat frequency of water-pumping cilia in mussels and ascidians, swimming velocity of sperm cells, ciliates and small (micro- and meso-scale) aquatic...... organisms using cilia or small appendages for propulsion. Here we summarize results from the literature and from own studies on bio-mechanical activities in response to changing temperature or manipulated viscosity at constant temperature, both having the same change in kinematic viscosity. The survey is...... used to assess to what extent the response is purely physical/mechanical or biological. We argue that a power-law dependence of bio-mechanical activity (a) on kinematic viscosity (ν), i.e. a ~ ν^−m, should be applied to available data. Based on a general close matching of the response data to power-law...

  9. Settlement and metamorphosis of Styela canopus Savigny larvae in response to some neurotransmitters and thyroxin

    Institute of Scientific and Technical Information of China (English)

    FENG Danqing; HUANG Ying; KE Caihuan; ZHOU Shiqiang; LI Shaojing

    2006-01-01

    The larvae of ascidian Styela canopus Savigny were treated with epinephrine, norepinephrine, L-DOPA, GABA and thyroxin to test the ability of these compounds to induce or inhibit larval settlement and metamorphosis. The results showed that epinephrine,norepinephrine and L-DOPA at the concentration of 1 μ mol/dm3 induced larval settlement and metamorphosis in S. canopus, with short exposure ( 1 h) to 1 μmoL/dm3 of L-DOPA inducing rapid settlement. In contrast, GABA at the concentrations of 0.1 ~100.0 μmol/dm3 significantly inhibited the settlement and metamorphosis of S. canopus larvae. In addition, thyroxin at 1 ~ 50μg/dm3 had no effect on larval settlement and metamorphosis in S. canopus. These results suggest the importance of neurotransmitters in the settlement and metamorphosis of S. canopus larvae.

  10. Ciliary and mucus-net filter feeding, with special reference to fluid mechanical characteristics

    DEFF Research Database (Denmark)

    Jørgensen, C.B.; Kiørboe, Thomas; Møhlenberg, F.;

    1984-01-01

    Filter characteristics were determined and compared in ciliary and mucus-net filter feeders. The ciliary feeders include the polychaete Sabella penicillus, the brachiopod Terebratulina retusa, the marine bivalves Monia squama, Cardium glaucum, and Petricola pholadiformis, and the freshwater...... bivalves Dreissena polymorpha, Unio pictorum and Anodonta cygnea. The mucus-net feeders are the polychaete Chaetopterus variopedatus, the gastropod Crepidula fornicata and the ascidians Styela clava, Ciona intestinalis, Ascidia virginea, A. obliqua and A. mentula. Efficiencies of particle retention as a...... function of particle size was determined by counting of particles in samples of inhalant and exhalant water. The lower threshold for efficient particle retention varied from .apprx. 6 .mu.m in T. retuso to .apprx. 1 .mu.m in D. polymorpha. Mucus nets efficiently retained particles down to 1-2 .mu.m. Filter...

  11. Diversity of Nonribosomal Peptide Synthetase Genes in the Microbial Metagenomes of Marine Sponges

    Directory of Open Access Journals (Sweden)

    Ute Hentschel

    2012-05-01

    Full Text Available Genomic mining revealed one major nonribosomal peptide synthetase (NRPS phylogenetic cluster in 12 marine sponge species, one ascidian, an actinobacterial isolate and seawater. Phylogenetic analysis predicts its taxonomic affiliation to the actinomycetes and hydroxy-phenyl-glycine as a likely substrate. Additionally, a phylogenetically distinct NRPS gene cluster was discovered in the microbial metagenome of the sponge Aplysina aerophoba, which shows highest similarities to NRPS genes that were previously assigned, by ways of single cell genomics, to a Chloroflexi sponge symbiont. Genomic mining studies such as the one presented here for NRPS genes, contribute to on-going efforts to characterize the genomic potential of sponge-associated microbiota for secondary metabolite biosynthesis.

  12. β-catenin-driven binary cell fate decisions in animal development.

    Science.gov (United States)

    Bertrand, Vincent

    2016-01-01

    The Wnt/β-catenin pathway plays key roles during animal development. In several species, β-catenin is used in a reiterative manner to regulate cell fate diversification between daughter cells following division. This binary cell fate specification mechanism has been observed in animals that belong to very diverse phyla: the nematode Caenorhabditis elegans, the annelid Platynereis, and the ascidian Ciona. It may also play a role in the regulation of several stem cell lineages in vertebrates. While the molecular mechanism behind this binary cell fate switch is not fully understood, it appears that both secreted Wnt ligands and asymmetric cortical factors contribute to the generation of the difference in nuclear β-catenin levels between daughter cells. β-Catenin then cooperates with lineage specific transcription factors to induce the expression of novel sets of transcription factors at each round of divisions, thereby diversifying cell fate. For further resources related to this article, please visit the WIREs website. PMID:26952169

  13. Effect of power plant heated effluent on distribution of sedentary fauna and flora

    International Nuclear Information System (INIS)

    Sedentary fauna and floral assemblages at heated (st.3) and non-heated (st.2) areas of the discharge canal of Madras atomic power station (MAPS) were observed over an annual cycle and compared with those of the intake area (st.1). Barnacles (30-57%) followed by hydroids, ascidians, gree mussels, tube worms (8-12%) brown mussels (5-10%), and sea anemones (10-14%) were conspicuous in the intake area. Macroalgae (15-59%) followed by barnacle (12-34%), tube worm (8-21%) and brown mussel (10-15%) were the components at st.2 whereas st.3 was bare except for bluegreen algal mats (100%) with few periwinkles. (author). 23 refs., 2 figs., 2 tabs

  14. Clinical Marine Toxicology: A European Perspective for Clinical Toxicologists and Poison Centers

    Directory of Open Access Journals (Sweden)

    Luc De Haro

    2013-08-01

    Full Text Available Clinical marine toxicology is a rapidly changing area. Many of the new discoveries reported every year in Europe involve ecological disturbances—including global warming—that have induced modifications in the chorology, behavior, and toxicity of many species of venomous or poisonous aquatic life including algae, ascidians, fish and shellfish. These changes have raised a number of public issues associated, e.g., poisoning after ingestion of contaminated seafood, envenomation by fish stings, and exposure to harmful microorganism blooms. The purpose of this review of medical and scientific literature in marine toxicology is to highlight the growing challenges induced by ecological disturbances that confront clinical toxicologists during the everyday job in the European Poison Centers.

  15. Microenvironmental Ecology of Phototrophs from Extreme Environments

    DEFF Research Database (Denmark)

    Trampe, Erik

    on spatial distribution of major taxonomic groups of phototrophs, detailed measurements of the optical properties of the ikaite matrix, in combination with various microscopic investigations of the phototrophic biofilms in the ikaite (Manuscript 2). Samples brought back for more advanced microscopy...... in Copenhagen were also used as the initial inocula for enrichments and cultivation of isolates of oxygenic phototrophs from the ikaite columns. Most of the culture work was conducted in the lab of Prof. Richard Castenholz at University of Oregon, OR, USA. Many isolates of phototrophs were obtained, several...... distinct biofilm communities associated with the didemnid ascidian Lissoclinum platella was evaluated by means of microsensor measurements of O2 and scalar irradiance, hyperspectral imaging of pigment distribution, variable chlorophyll fluorescence assessment of relative PSII electron transport rates...

  16. An Early Cambrian tunicate from China.

    Science.gov (United States)

    Shu, D G; Chen, L; Han, J; Zhang, X L

    2001-05-24

    Like the Burgess Shales of Canada, the Chengjiang Lagerstätte from the Lower Cambrian of China is renowned for the detailed preservation as fossils of delicate, soft-bodied creatures, providing an insight into the Cambrian explosion. The fossils of possible hemichordate chordates and vertebrates have attracted particular attention. Tunicates, or urochordates, comprise the most basal chordate clade, and details of their evolution could be important in understanding the sequence of character acquisition that led to the emergence of chordates and vertebrates. However, definitive fossils of tunicates from the Cambrian are scarce or debatable. Here we report a probable tunicate Cheungkongella ancestralis from the Chengjiang fauna. It resembles the extant ascidian tunicate genus Styela whose morphology could be useful in understanding the origin of the vertebrates. PMID:11373678

  17. Data on four apoptosis-related genes in the colonial tunicate Botryllus schlosseri.

    Science.gov (United States)

    Franchi, Nicola; Ballin, Francesca; Manni, Lucia; Schiavon, Filippo; Ballarin, Loriano

    2016-09-01

    The data described are related to the article entitled "Recurrent phagocytosis-induced apoptosis in the cyclical generation change of the compound ascidian Botryllus schlosseri" (Franchi et al., 2016) [1]. Four apoptosis-related genes, showing high similarity with mammalian Bax (a member of the Bcl-2 protein family), AIF1 (apoptosis-inducing factor-1), PARP1 (poly ADP ribose polymerase-1) and IAP7 (inhibitor of apoptosis-7) were identified from the analysis of the trascriptome of B. schlosseri. They were named BsBax, BsAIF1, BsPARP1 and BsIAP7. Here, their deduced amino acid sequence were compared with known sequences of orthologous genes from other deuterostome species together with a study of their identity/similarity. PMID:27294183

  18. The significance of Ciona intestinalis as a stem organism in integrative studies of functional evolution of the chordate endocrine, neuroendocrine, and nervous systems.

    Science.gov (United States)

    Matsubara, Shin; Kawada, Tsuyoshi; Sakai, Tsubasa; Aoyama, Masato; Osugi, Tomohiro; Shiraishi, Akira; Satake, Honoo

    2016-02-01

    Ascidians are the closest phylogenetic neighbors to vertebrates and are believed to conserve the evolutionary origin in chordates of the endocrine, neuroendocrine, and nervous systems involving neuropeptides and peptide hormones. Ciona intestinalis harbors various homologs or prototypes of vertebrate neuropeptides and peptide hormones including gonadotropin-releasing hormones (GnRHs), tachykinins (TKs), and calcitonin, as well as Ciona-specific neuropeptides such as Ciona vasopressin, LF, and YFV/L peptides. Moreover, molecular and functional studies on Ciona tachykinin (Ci-TK) have revealed the novel molecular mechanism of inducing oocyte growth via up-regulation of vitellogenesis-associated protease activity, which is expected to be conserved in vertebrates. Furthermore, a series of studies on Ciona GnRH receptor paralogs have verified the species-specific regulation of GnRHergic signaling including unique signaling control via heterodimerization among multiple GnRH receptors. These findings confirm the remarkable significance of ascidians in investigations of the evolutionary processes of the peptidergic systems in chordates, leading to the promising advance in the research on Ciona peptides in the next stage based on the recent development of emerging technologies including genome-editing techniques, peptidomics-based multi-color staining, machine-learning prediction, and next-generation sequencing. These technologies and bioinformatic integration of the resultant "multi-omics" data will provide unprecedented insights into the comprehensive understanding of molecular and functional regulatory mechanisms of the Ciona peptides, and will eventually enable the exploration of both conserved and diversified endocrine, neuroendocrine, and nervous systems in the evolutionary lineage of chordates. PMID:26031189

  19. Evolution of anterior Hox regulatory elements among chordates

    Directory of Open Access Journals (Sweden)

    Natale Alfonso

    2011-11-01

    Full Text Available Abstract Background The Hox family of transcription factors has a fundamental role in segmentation pathways and axial patterning of embryonic development and their clustered organization is linked with the regulatory mechanisms governing their coordinated expression along embryonic axes. Among chordates, of particular interest are the Hox paralogous genes in groups 1-4 since their expression is coupled to the control of regional identity in the anterior nervous system, where the highest structural diversity is observed. Results To investigate the degree of conservation in cis-regulatory components that form the basis of Hox expression in the anterior nervous system, we have used assays for transcriptional activity in ascidians and vertebrates to compare and contrast regulatory potential. We identified four regulatory sequences located near the CiHox1, CiHox2 and CiHox4 genes of the ascidian Ciona intestinalis which direct neural specific domains of expression. Using functional assays in Ciona and vertebrate embryos in combination with sequence analyses of enhancer fragments located in similar positions adjacent to Hox paralogy group genes, we compared the activity of these four Ciona cis-elements with a series of neural specific enhancers from the amphioxus Hox1-3 genes and from mouse Hox paralogous groups 1-4. Conclusions This analysis revealed that Kreisler and Krox20 dependent enhancers critical in segmental regulation of the hindbrain appear to be specific for the vertebrate lineage. In contrast, neural enhancers that function as Hox response elements through the action of Hox/Pbx binding motifs have been conserved during chordate evolution. The functional assays reveal that these Hox response cis-elements are recognized by the regulatory components of different and extant species. Together, our results indicate that during chordate evolution, cis-elements dependent upon Hox/Pbx regulatory complexes, are responsible for key aspects of

  20. Antibiotic, cytotoxic and enzyme inhibitory activity of crude extracts from Brazilian marine invertebrates Atividade antibiótica, citotóxica e de inibição enzimática de extratos brutos de invertebrados marinhos do Brasil

    Directory of Open Access Journals (Sweden)

    Mirna H. R. Seleghim

    2007-09-01

    Full Text Available Herein we present the results of a screening with 349 crude extracts of Brazilian marine sponges, ascidians, bryozoans and octocorals, against 16 strains of susceptible and antibiotic-resistant bacteria, one yeast (Candida albicans, Mycobacterium tuberculosis H37Rv, three cancer cell lines MCF-7 (breast, B16 (murine melanoma and HCT8 (colon, and Leishmania tarentolae adenine phosphoribosyl transferase (L-APRT enzyme. Less than 15% of marine sponge crude extracts displayed antibacterial activity, both against susceptible and antibiotic-resistant bacteria. Up to 40% of marine sponge crude extracts displayed antimycobacterial activity against M. tuberculosis H37Rv. Cytotoxicity was observed for 18% of marine sponge crude extracts. Finally, less than 3% of sponge extracts inhibited L-APRT. Less than 10% of ascidian crude extracts displayed antibacterial activity. More than 25% of ascidian crude extracts were active against M. tuberculosis and the three cancer cell lines. Only two crude extracts from the ascidian Polysyncraton sp. collected in different seasons (1995 and 1997 displayed activity against L-APRT. Less than 2% of bryozoan and octocoral crude extracts presented antibacterial activity, but a high percentage of crude extracts from bryozoan and octororal displayed cytotoxic (11% and 30%, respectively and antimycobacterial (60% activities. The extract of only one species of bryozoan, Bugula sp., presented inhibitory activity against L-APRT. Overall, the crude extracts of marine invertebrates herein investigated presented a high level of cytotoxic and antimycobacterial activities, a lower level of antibacterial activity and only a small number of crude extracts inhibited L-APRT. Taxonomic analysis of some of the more potently active crude extracts showed the occurrence of biological activity in taxa that have been previously chemically investigated. These include marine sponges belonging to genera Aaptos, Aplysina, Callyspongia, Haliclona

  1. Biofouling community pattern on various metallic surfaces in the coastal waters of Kalpakkam, Southwestern Bay of Bengal

    International Nuclear Information System (INIS)

    . 100 cm-2. The major fouling organisms such as, barnacle, green mussel and ascidian constituted ∼ 70-80% of the total fouling. In the present study, sequence of fouling succession was as follows, barnacle - hydroid - sea anemone - ascidian and finally green mussel (Perna viridis Linn. 1758). The paper also discusses species diversity indices (diversity, richness and evenness) in detail. (author)

  2. An epizootic of Florida manatees associated with a dinoflagellate bloom

    Science.gov (United States)

    O'Shea, T.J.; Rathbun, G.B.; Bonde, R.K.; Buergelt, C.D.; Odell, D.K.

    1991-01-01

    Over a 10-wk period in early 1982, 39 Florida manatees (Trichechus manatus latirostris) were found dead in the lower Caloosahatchee River and nearby waters of southwestern Florida. Two were killed by boats. The remainder showed no evidence of trauma. Lesions indicative of infectious agents were not identified, and bacteriological and contaminant residue findings were unremarkable. Nonspecific lesions of congestion and hemorrhage were identified in brain tissue. Numerous reports were also received of manatee morbidity. Some distressed manatees showed no biochemical lesions in clinical analyses of blood samples and recovered quickly. Timing of manatee illnesses coincided with fish and double-crested cormorant (Phalacrocorax auritus) mortality and morbidity. A widespread bloom of the dinoflagellate red tide organism (Gymnodinium breve) also coincided with these incidents. G. breve produces potent neurotoxins (brevetoxins). Circumstantial evidence links these events, and possible routes of exposure may include ingestion of filter-feeding ascidians. Ecological conditions that magnified the extent of the epizootic included an early dispersal of manatees into the area from a nearby winter aggregation site and unusually high salinities that facilitated the inshore spread of the red tide bloom. Management responses to future episodes of red tide in manatee areas are suggested.

  3. Observations on the morphology of embryonic and larval development in Styela canopus Savigny

    Institute of Scientific and Technical Information of China (English)

    Huang Ying; Ke Caihuan; Feng Danqing; Zhou Shiqiang; Li Fuxue

    2003-01-01

    The morphological characters on different developmental phases of embryo and larva and the schedule of the whole early developmental process in Styela canopus were observed and described.The types of reproduction and early development as well as the morphology of egg and larva in different ascidian species were compared. Styela canopus is oviparous. Its egg, 230.4~336.0 μm in diameter, is equipped with extraembryonic cell layers measured 43.2~ 63.0 μm thick. The early development of Styela canopus is typical urodele development, including fertilization, cleavage, gastrulation, tadpole in membrane, tadpole, initiating metamorphosis and juvenile. The tadpole of Styela canopus, with a length of 0.6~0.9 mm, consists of trunk and tail. There are obvious notochord, ocellus and adhesive papillae in the tadpole. Under the water temperature of (25 ± 0.5)℃ and the salinity of 27.0, the larva was hatched after 9.5~ 11.0 h since the fertilization.

  4. Cryptic species and genetic structure in Didemnum granulatum Tokioka, 1954 (Tunicata: Ascidiacea) from the southern Brazilian coast.

    Science.gov (United States)

    Bouzon, J L; Vargas, S M; Oliveira Neto, J F; Stoco, P H; Brandini, F P

    2014-11-01

    Didemnum granulatum is a colonial fouling ascidian that lives in subtidal substrates, worldwide. It exhibits two morphotypes, orange and beige. In this study, we verified if the color morphotypes and/or the spatial distribution of specimens in different islands might be associated to patterns of genetic structure of a single species, or if they represent distinct cryptic species. Specimens were collected in four islands, along the coast of the Santa Catarina state. A segment of 490 bp from the mitochondrial gene cytochrome c oxidase subunit 1 (COI) was amplified from 45 samples. Twenty-one haplotypes were identified. The total haplotype diversity (0.912) and the total nucleotide diversity (0.044) were high. The global Fst of the populations analyzed was 0.97, with most of the variation occurring between orange and beige groups (82.19%). The variation found between populations within groups was 15.37%, and 2.45% within populations. Haplotype networks and the neighbor-joining tree showed clear genetic divergence between individuals of distinct colors, and between the islands. These evidences strongly support the presence of a complex of two cryptic species for D. granulatum occupying the studied area. Both species were also highly genetically structured between islands, suggesting that the conservation process of these populations is complex. PMID:25627604

  5. The cult of amphioxus in German Darwinism; or, our gelatinous ancestors in Naples' blue and balmy bay.

    Science.gov (United States)

    Hopwood, Nick

    2015-01-01

    Biologists having rediscovered amphioxus, also known as the lancelet or Branchiostoma, it is time to reassess its place in early Darwinist debates over vertebrate origins. While the advent of the ascidian-amphioxus theory and challenges from various competitors have been, documented, this article offers a richer account of the public appeal of amphioxus as a primitive ancestor. The focus is on how the 'German Darwin' Ernst Haeckel persuaded general magazine and newspaper readers to revere this "flesh of our flesh and blood of our blood", and especially on Das neue Laienbrevier des Haeckelismus (The new lay breviary of Haeckelism) by Moritz Reymond with cartoons by Fritz Steub. From the late 1870s these successful little books of verse introduced the Neapolitan discoveries that made the animal's name and satirized Haeckel's rise as high priest of its cult. One song is reproduced and translated here, with a contemporary "imitation" by the Canadian palaeontologist Edward John Chapman, and extracts from others. Predating the American "It's a long way from amphioxus" by decades, these rhymes dramatize neglected 'species politics' of Darwinism and highlight the roles of humour in negotiating evolution. PMID:26013195

  6. NMR structural determination of unique invertebrate glycosaminoglycans endowed with medical properties.

    Science.gov (United States)

    Pomin, Vitor H

    2015-09-01

    Glycosaminoglycans (GAGs) are sulfated polysaccharides of complex structure endowed with numerous biomedical functions. Although ubiquitously distributed in vertebrates, GAGs can also occur in certain terrestrial or marine invertebrates. Solution nuclear magnetic resonance (NMR) spectroscopy has been the analytical technique mostly employed in structural characterization of GAGs from any source. This review aims at illustrating the application of NMR in structural determination of few representative invertebrate GAG examples of unique structures and endowed with therapeutic actions. They are the holothurian fucosylated chondroitin sulfate, the acharan sulfate isolated from the snail Achatina fulica, the dermatan sulfates with distinct sulfation patterns extracted from ascidian species, the sulfated glucuronic acid-containing heparan sulfate isolated from the gastropode Nodipecten nodosum, and the hybrid heparin/heparan sulfate molecule obtained from the shrimp Litopenaeus vannamei. These invertebrate GAGs exhibit distinct structures when compared to those extracted from mammalian GAGs. The distinct structures of the invertebrate GAGs lead also to different mechanisms of actions as compared to the mammalian GAG standards. Invertebrate GAGs comprise promising therapeutic candidates in fights against diseases. Solution NMR has been playing a pivotal role in this carbohydrate-based drug research, discovery and development. PMID:26083200

  7. CiMT-1, an unusual chordate metallothionein gene in Ciona intestinalis genome: structure and expression studies.

    Science.gov (United States)

    Franchi, Nicola; Boldrin, Francesco; Ballarin, Loriano; Piccinni, Ester

    2011-02-01

    The present article reports on the characterization of the urochordate metallothionein (MT) gene, CiMT-1, from the solitary ascidian Ciona intestinalis. The predicted protein is shorter than other known deuterostome MTs, having only 39 amino acids. The gene has the same tripartite structure as vertebrate MTs, with some features resembling those of echinoderm MTs. The promoter region shows the canonical cis-acting elements recognized by transcription factors that respond to metal, ROS, and cytokines. Unusual sequences, described in fish and echinoderms, are also present. In situ hybridization suggests that only a population of hemocytes involved in immune responses, i.e. granular amebocytes, express CiMT-1 mRNA. These observations support the idea that urochordates perform detoxification through hemocytes, and that MTs may play important roles in inflammatory humoral responses in tunicates. The reported data offer new clues for better understanding the evolution of these multivalent proteins from non-vertebrate to vertebrate chordates and reinforce their functions in detoxification and immunity. PMID:21328559

  8. A protein involved in the assembly of an extracellular calcium storage matrix.

    Science.gov (United States)

    Glazer, Lilah; Shechter, Assaf; Tom, Moshe; Yudkovski, Yana; Weil, Simy; Aflalo, Eliahu David; Pamuru, Ramachandra Reddy; Khalaila, Isam; Bentov, Shmuel; Berman, Amir; Sagi, Amir

    2010-04-23

    Gastroliths, the calcium storage organs of crustaceans, consist of chitin-protein-mineral complexes in which the mineral component is stabilized amorphous calcium carbonate. To date, only three proteins, GAP 65, gastrolith matrix protein (GAMP), and orchestin, have been identified in gastroliths. Here, we report a novel protein, GAP 10, isolated from the gastrolith of the crayfish Cherax quadricarinatus and specifically expressed in its gastrolith disc. The encoding gene was cloned by partial sequencing of the protein extracted from the gastrolith matrix. Based on an assembled microarray cDNA chip, GAP 10 transcripts were found to be highly (12-fold) up-regulated in premolt gastrolith disc and significantly down-regulated in the hypodermis at the same molt stage. The deduced protein sequence of GAP 10 lacks chitin-binding domains and does not show homology to known proteins in the GenBank data base. It does, however, have an amino acid composition that has similarity to proteins extracted from invertebrate and ascidian-calcified extracellular matrices. The GAP 10 sequence contains a predicted signal peptide and predicted phosphorylation sites. In addition, the protein is phosphorylated and exhibits calcium-binding ability. Repeated daily injections of GAP 10 double strand RNA to premolt C. quadricarinatus resulted in a prolonged premolt stage and in the development of gastroliths with irregularly rough surfaces. These findings suggest that GAP 10 may be involved in the assembly of the gastrolith chitin-protein-mineral complex, particularly in the deposition of amorphous calcium carbonate. PMID:20150428

  9. Physical association between a novel plasma-membrane structure and centrosome orients cell division

    Science.gov (United States)

    Negishi, Takefumi; Miyazaki, Naoyuki; Murata, Kazuyoshi; Yasuo, Hitoyoshi; Ueno, Naoto

    2016-01-01

    In the last mitotic division of the epidermal lineage in the ascidian embryo, the cells divide stereotypically along the anterior-posterior axis. During interphase, we found that a unique membrane structure invaginates from the posterior to the centre of the cell, in a microtubule-dependent manner. The invagination projects toward centrioles on the apical side of the nucleus and associates with one of them. Further, a cilium forms on the posterior side of the cell and its basal body remains associated with the invagination. A laser ablation experiment suggests that the invagination is under tensile force and promotes the posterior positioning of the centrosome. Finally, we showed that the orientation of the invaginations is coupled with the polarized dynamics of centrosome movements and the orientation of cell division. Based on these findings, we propose a model whereby this novel membrane structure orchestrates centrosome positioning and thus the orientation of cell division axis. DOI: http://dx.doi.org/10.7554/eLife.16550.001 PMID:27502556

  10. Macrofauna associated to Mycale microsigmatosa (Porifera, Demospongiae) in Rio de Janeiro State, SE Brazil

    Science.gov (United States)

    Ribeiro, Suzi M.; Omena, Elianne P.; Muricy, Guilherme

    2003-08-01

    The macrofauna (endo- and epi-biotic) associated to the sponge Mycale ( Carmia) microsigmatosa Arndt, 1927 was studied at three sites in Rio de Janeiro State, Brazil (Arraial do Cabo, Niterói, and Rio de Janeiro). A total of 2235 individuals (over 1 mm long) of 75 invertebrate species were found associated to 19 specimens of the sponge. The most abundant and diverse taxa were the crustaceans (83%, 31 spp.), polychetes (10%, 18 spp.), and molluscs (3.7%, 15 spp.). Cnidarians, platyhelminthes, ascidians, echinoderms, pycnogonids, bryozoans, and sponges were also represented. Amphipod crustaceans were the dominant group, comprising 61% of all individuals collected. Species richness and abundance of associated fauna were highly correlated with sponge volume, but diversity and evenness were not. The site of collection influenced the species composition of the fauna associated to M. microsigmatosa but did not change significantly its diversity, abundance, richness, and dominance patterns of higher taxa. Pregnant females and juvenile stages of 29% of the species associated, including crustaceans, molluscs, echinoderms, and pycnogonids were frequently found inside M. microsigmatosa. Although many of these organisms do occur and reproduce in other habitats outside the sponge as well, M. microsigmatosa is also important for their reproduction and survivorship, thus contributing for the maintenance of biodiversity in Southwestern Atlantic sublittoral rocky shores.

  11. Characteristics of the Mesophotic Megabenthic Assemblages of the Vercelli Seamount (North Tyrrhenian Sea)

    Science.gov (United States)

    Bo, Marzia; Bertolino, Marco; Borghini, Mireno; Castellano, Michela; Covazzi Harriague, Anabella; Di Camillo, Cristina Gioia; Gasparini, GianPietro; Misic, Cristina; Povero, Paolo; Pusceddu, Antonio; Schroeder, Katrin; Bavestrello, Giorgio

    2011-01-01

    The biodiversity of the megabenthic assemblages of the mesophotic zone of a Tyrrhenian seamount (Vercelli Seamount) is described using Remotely Operated Vehicle (ROV) video imaging from 100 m depth to the top of the mount around 61 m depth. This pinnacle hosts a rich coralligenous community characterized by three different assemblages: (i) the top shows a dense covering of the kelp Laminaria rodriguezii; (ii) the southern side biocoenosis is mainly dominated by the octocorals Paramuricea clavata and Eunicella cavolinii; while (iii) the northern side of the seamount assemblage is colonized by active filter-feeding organisms such as sponges (sometimes covering 100% of the surface) with numerous colonies of the ascidian Diazona violacea, and the polychaete Sabella pavonina. This study highlights, also for a Mediterranean seamount, the potential role of an isolated rocky peak penetrating the euphotic zone, to work as an aggregating structure, hosting abundant benthic communities dominated by suspension feeders, whose distribution may vary in accordance to the geomorphology of the area and the different local hydrodynamic conditions. PMID:21304906

  12. 3D-printed microwell arrays for Ciona microinjection and timelapse imaging.

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    Clint Gregory

    Full Text Available Ascidians such as Ciona are close chordate relatives of the vertebrates with small, simple embryonic body plans and small, simple genomes. The tractable size of the embryo offers considerable advantages for in toto imaging and quantitative analysis of morphogenesis. For functional studies, Ciona eggs are considerably more challenging to microinject than the much larger eggs of other model organisms such as zebrafish and Xenopus. One of the key difficulties is in restraining the eggs so that the microinjection needle can be easily introduced and withdrawn. Here we develop and test a device to cast wells in agarose that are each sized to hold a single egg. This injection mold is fabricated by micro-resolution stereolithography with a grid of egg-sized posts that cast corresponding wells in agarose. This 3D printing technology allows the rapid and inexpensive testing of iteratively refined prototypes. In addition to their utility in microinjection, these grids of embryo-sized wells are also valuable for timelapse imaging of multiple embryos.

  13. Toll-like receptors of deuterostome invertebrates

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    Honoo eSatake

    2012-02-01

    Full Text Available Defensive systems against pathogens are responsible not only for survival or lifetime of an individual but also for the evolution of a species. Innate immunity is expected to be more important for invertebrates than mammals, given that adaptive immunity has not been acquired in the former. Toll-like receptors (TLRs have been shown to play a crucial role in host defense of pathogenic microbes in innate immunity of mammals. Recent genome-wide analyses have suggested that TLR or their related genes are conserved in invertebrates. In particular, numerous TLR-related gene candidates were detected in deuterostome invertebrates including a sea urchin (222 TLR-related gene candidates and amphioxus (72 TLR-related gene candidates. Molecular phylogenetic analysis verified that most of sea urchin or amphioxus TLR candidates are paralogous, suggesting that these organisms expanded TLR-related genes in a species-specific manner. In contrast, another deuterostome invertebrate, an ascidian, Ciona intestinalis, was found to possess only two TLR genes. Moreover, Ciona TLRs, Ci-TLR1 and -2, were shown to possess hybrid functionality of mammalian TLRs. Such functionality of Ci-TLRs could not be predicted by sequence comparison with vertebrate TLRs, indicating the confounding evolutionary lineages of deuterostome invertebrate TLRs or their candidates. In this review article, we present recent advances in studies of TLRs or their candidates of deuterostome invertebrates, and provide insight into an evolutionary process of TLRs.

  14. Voltage sensitive phosphatases: emerging kinship to protein tyrosine phosphatases from structure-function research

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    Kirstin eHobiger

    2015-02-01

    Full Text Available The transmembrane protein Ci-VSP from the ascidian Ciona intestinalis was described as first member of a fascinating family of enzymes, the voltage sensitive phosphatases (VSPs. Ci-VSP and its voltage-activated homologs from other species are stimulated by positive membrane potentials and dephosphorylate the head groups of negatively charged phosphoinositide phosphates (PIPs. In doing so, VSPs act as control centers at the cytosolic membrane surface, because they intervene in signaling cascades that are mediated by PIP lipids. The characteristic motif CX5RT/S in the active site classifies VSPs as members of the huge family of cysteine-based protein tyrosine phosphatases (PTPs. Although PTPs have already been well characterized regarding both, structure and function, their relationship to VSPs has drawn only limited attention so far. Therefore, the intention of this review is to give a short overview about the extensive knowledge about PTPs in relation to the facts known about VSPs. Here, we concentrate on the structural features of the catalytic domain which are similar between both classes of phosphatases and their consequences for the enzymatic function. By discussing results obtained from crystal structures, molecular dynamics simulations, and mutagenesis studies, a possible mechanism for the catalytic cycle of VSPs is presented based on that one proposed for PTPs. In this way, we want to link the knowledge about the catalytic activity of VSPs and PTPs.

  15. Cadmium effects in food chain experiments with marine plankton algae (dinophyta) and benthic filter feeders(Tunicata)

    Science.gov (United States)

    Kayser, H.

    The dinoflagellate Scrippsiella faeroense was grown in continuous flow-through cultures (10 1 turbidostat), the outflow leading into vessels containing tunicates of the species Ciona intestinalis, Ascidiella aspersa, Molgula manhattensi and Botryllus schlosseri. The culture medium consisted of natural sea water enriched only with N and P components. CdCl 2 was added to the system at sublethal concentrations. Algal growth wass affected at a Cd ++ concentration of 10 μg·1 -1; sublethal toxicity thresholds of the tunicates ranged from 5 to 10 μg·1 -1. Cadmium accumulation was much higer in the algae than in the tunicates; in spite of the continuous supply of relatively highly Cd contaminated algae, the Cd content of algae-fed tunicates increased insignificantly by comparison with unfed specimens. Only a small percentage of the Cd offered via the food algae was actually assimilated by the ascidians during the first 3 weeks of the experiment. Cd content of the tunicates remained almost constant for the next 2 weeks of the experiment, indicating that ingestion and excretion of the metal was at equilibrium. The concentration factor of Cd decreased through the trophic chain.

  16. Transcription factors ETS2 and MESP1 transdifferentiate human dermal fibroblasts into cardiac progenitors.

    Science.gov (United States)

    Islas, Jose Francisco; Liu, Yu; Weng, Kuo-Chan; Robertson, Matthew J; Zhang, Shuxing; Prejusa, Allan; Harger, John; Tikhomirova, Dariya; Chopra, Mani; Iyer, Dinakar; Mercola, Mark; Oshima, Robert G; Willerson, James T; Potaman, Vladimir N; Schwartz, Robert J

    2012-08-01

    Unique insights for the reprograming of cell lineages have come from embryonic development in the ascidian Ciona, which is dependent upon the transcription factors Ci-ets1/2 and Ci-mesp to generate cardiac progenitors. We tested the idea that mammalian v-ets erythroblastosis virus E26 oncogene homolog 2 (ETS2) and mesoderm posterior (MESP) homolog may be used to convert human dermal fibroblasts into cardiac progenitors. Here we show that murine ETS2 has a critical role in directing cardiac progenitors during cardiopoiesis in embryonic stem cells. We then use lentivirus-mediated forced expression of human ETS2 to convert normal human dermal fibroblasts into replicative cells expressing the cardiac mesoderm marker KDR(+). However, although neither ETS2 nor the purported cardiac master regulator MESP1 can by themselves generate cardiac progenitors de novo from fibroblasts, forced coexpression of ETS2 and MESP1 or cell treatment with purified proteins reprograms fibroblasts into cardiac progenitors, as shown by the de novo appearance of core cardiac transcription factors, Ca(2+) transients, and sarcomeres. Our data indicate that ETS2 and MESP1 play important roles in a genetic network that governs cardiopoiesis. PMID:22826236

  17. Functional Brachyury binding sites establish a temporal read-out of gene expression in the Ciona notochord.

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    Lavanya Katikala

    2013-10-01

    Full Text Available The appearance of the notochord represented a milestone in Deuterostome evolution. The notochord is necessary for the development of the chordate body plan and for the formation of the vertebral column and numerous organs. It is known that the transcription factor Brachyury is required for notochord formation in all chordates, and that it controls transcription of a large number of target genes. However, studies of the structure of the cis-regulatory modules (CRMs through which this control is exerted are complicated in vertebrates by the genomic complexity and the pan-mesodermal expression territory of Brachyury. We used the ascidian Ciona, in which the single-copy Brachyury is notochord-specific and CRMs are easily identifiable, to carry out a systematic characterization of Brachyury-downstream notochord CRMs. We found that Ciona Brachyury (Ci-Bra controls most of its targets directly, through non-palindromic binding sites that function either synergistically or individually to activate early- and middle-onset genes, respectively, while late-onset target CRMs are controlled indirectly, via transcriptional intermediaries. These results illustrate how a transcriptional regulator can efficiently shape a shallow gene regulatory network into a multi-tiered transcriptional output, and provide insights into the mechanisms that establish temporal read-outs of gene expression in a fast-developing chordate embryo.

  18. Acquisition of the dorsal structures in chordate amphioxus

    Science.gov (United States)

    Morov, Arseniy R.; Ukizintambara, Tharcisse; Sabirov, Rushan M.

    2016-01-01

    Acquisition of dorsal structures, such as notochord and hollow nerve cord, is likely to have had a profound influence upon vertebrate evolution. Dorsal formation in chordate development thus has been intensively studied in vertebrates and ascidians. However, the present understanding does not explain how chordates acquired dorsal structures. Here we show that amphioxus retains a key clue to answer this question. In amphioxus embryos, maternal nodal mRNA distributes asymmetrically in accordance with the remodelling of the cortical cytoskeleton in the fertilized egg, and subsequently lefty is first expressed in a patch of blastomeres across the equator where wnt8 is expressed circularly and which will become the margin of the blastopore. The lefty domain co-expresses zygotic nodal by the initial gastrula stage on the one side of the blastopore margin and induces the expression of goosecoid, not-like, chordin and brachyury1 genes in this region, as in the oral ectoderm of sea urchin embryos, which provides a basis for the formation of the dorsal structures. The striking similarity in the gene regulations and their respective expression domains when comparing dorsal formation in amphioxus and the determination of the oral ectoderm in sea urchin embryos suggests that chordates derived from an ambulacrarian-type blastula with dorsoventral inversion. PMID:27307516

  19. Acquisition of the dorsal structures in chordate amphioxus.

    Science.gov (United States)

    Morov, Arseniy R; Ukizintambara, Tharcisse; Sabirov, Rushan M; Yasui, Kinya

    2016-06-01

    Acquisition of dorsal structures, such as notochord and hollow nerve cord, is likely to have had a profound influence upon vertebrate evolution. Dorsal formation in chordate development thus has been intensively studied in vertebrates and ascidians. However, the present understanding does not explain how chordates acquired dorsal structures. Here we show that amphioxus retains a key clue to answer this question. In amphioxus embryos, maternal nodal mRNA distributes asymmetrically in accordance with the remodelling of the cortical cytoskeleton in the fertilized egg, and subsequently lefty is first expressed in a patch of blastomeres across the equator where wnt8 is expressed circularly and which will become the margin of the blastopore. The lefty domain co-expresses zygotic nodal by the initial gastrula stage on the one side of the blastopore margin and induces the expression of goosecoid, not-like, chordin and brachyury1 genes in this region, as in the oral ectoderm of sea urchin embryos, which provides a basis for the formation of the dorsal structures. The striking similarity in the gene regulations and their respective expression domains when comparing dorsal formation in amphioxus and the determination of the oral ectoderm in sea urchin embryos suggests that chordates derived from an ambulacrarian-type blastula with dorsoventral inversion. PMID:27307516

  20. Tunicates: exploring the sea shores and roaming the open ocean. A tribute to Thomas Huxley.

    Science.gov (United States)

    Lemaire, Patrick; Piette, Jacques

    2015-06-01

    This review is a tribute to the remarkable contributions of Thomas Huxley to the biology of tunicates, the likely sister group of vertebrates. In 1851, the great biologist and philosopher published two landmark papers on pelagic tunicates in the Philosophical Transactions of the Royal Society. They were dedicated to the description of the adult anatomy and life cycle of thaliaceans and appendicularians, the pelagic relatives of ascidians. In the first part of this review, we discuss the novel anatomical observations and evolutionary hypotheses made by Huxley, which would have a lasting influence on tunicate biology. We also briefly comment on the more philosophical reflections of Huxley on individuality. In the second part, we stress the originality and relevance of past and future studies of tunicates in the resolution of major biological issues. In particular, we focus on the complex relationship between genotype and phenotype and the phenomenon of developmental system drift. We propose that more than 150 years after Huxley's papers, tunicate embryos are still worth studying in their own right, independently of their evolutionary proximity to vertebrates, as they provide original and crucial insights into the process of animal evolution. Tunicates are still at the forefront of biological research. PMID:26085517

  1. A non-oxo methanolate-bridged divanadium(IV) complex with tris(2-sulfanidylphenyl)phosphane ligands: synthesis, structural characterization and magnetic investigation.

    Science.gov (United States)

    Wu, Hong Ming; Chang, Ya Ho; Su, Chia Lin; Lee, Gene Hsiang; Hsu, Hua Fen

    2016-05-01

    Vanadium chemistry is of interest due its biological relevance and medical applications. In particular, the interactions of high-valent vanadium ions with sulfur-containing biologically important molecules, such as cysteine and glutathione, might be related to the redox conversion of vanadium in ascidians, the function of amavadin (a vanadium-containing anion) and the antidiabetic behaviour of vanadium compounds. A mechanistic understanding of these aspects is important. In an effort to investigate high-valent vanadium-sulfur chemistry, we have synthesized and characterized the non-oxo divanadium(IV) complex salt tetraphenylphosphonium tri-μ-methanolato-κ(6)O:O-bis({tris[2-sulfanidyl-3-(trimethylsilyl)phenyl]phosphane-κ(4)P,S,S',S''}vanadium(IV)) methanol disolvate, (C24H20P)[V(IV)2(μ-OCH3)3(C27H36PS3)2]·2CH3OH. Two V(IV) metal centres are bridged by three methanolate ligands, giving a C2-symmetric V2(μ-OMe)3 core structure. Each V(IV) centre adopts a monocapped trigonal antiprismatic geometry, with the P atom situated in the capping position and the three S atoms and three O atoms forming two triangular faces of the trigonal antiprism. The magnetic data indicate a paramagnetic nature of the salt, with an S = 1 spin state. PMID:27146571

  2. Investigation of Indolglyoxamide and Indolacetamide Analogues of Polyamines as Antimalarial and Antitrypanosomal Agents

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    Jiayi Wang

    2014-05-01

    Full Text Available Pure compound screening has previously identified the indolglyoxy lamidospermidine ascidian metabolites didemnidine A and B (2 and 3 to be weak growth inhibitors of Trypanosoma brucei rhodesiense (IC50 59 and 44 μM, respectively and Plasmodium falciparum (K1 dual drug resistant strain (IC50 41 and 15 μM, respectively, but lacking in selectivity (L6 rat myoblast, IC50 24 μM and 25 μM, respectively. To expand the structure–activity relationship of this compound class towards both parasites, we have prepared and biologically tested a library of analogues that includes indoleglyoxyl and indoleacetic “capping acids”, and polyamines including spermine (PA3-4-3 and extended analogues PA3-8-3 and PA3-12-3. 7-Methoxy substituted indoleglyoxylamides were typically found to exhibit the most potent antimalarial activity (IC50 10–92 nM but with varying degrees of selectivity versus the L6 rat myoblast cell line. A 6-methoxyindolglyoxylamide analogue was the most potent growth inhibitor of T. brucei (IC50 0.18 μM identified in the study: it, however, also exhibited poor selectivity (L6 IC50 6.0 μM. There was no apparent correlation between antimalarial and anti-T. brucei activity in the series. In vivo evaluation of one analogue against Plasmodium berghei was undertaken, demonstrating a modest 20.9% reduction in parasitaemia.

  3. Structural shifts of aldehyde dehydrogenase enzymes were instrumental for the early evolution of retinoid-dependent axial patterning in metazoans.

    Science.gov (United States)

    Sobreira, Tiago J P; Marlétaz, Ferdinand; Simões-Costa, Marcos; Schechtman, Deborah; Pereira, Alexandre C; Brunet, Frédéric; Sweeney, Sarah; Pani, Ariel; Aronowicz, Jochanan; Lowe, Christopher J; Davidson, Bradley; Laudet, Vincent; Bronner, Marianne; de Oliveira, Paulo S L; Schubert, Michael; Xavier-Neto, José

    2011-01-01

    Aldehyde dehydrogenases (ALDHs) catabolize toxic aldehydes and process the vitamin A-derived retinaldehyde into retinoic acid (RA), a small diffusible molecule and a pivotal chordate morphogen. In this study, we combine phylogenetic, structural, genomic, and developmental gene expression analyses to examine the evolutionary origins of ALDH substrate preference. Structural modeling reveals that processing of small aldehydes, such as acetaldehyde, by ALDH2, versus large aldehydes, including retinaldehyde, by ALDH1A is associated with small versus large substrate entry channels (SECs), respectively. Moreover, we show that metazoan ALDH1s and ALDH2s are members of a single ALDH1/2 clade and that during evolution, eukaryote ALDH1/2s often switched between large and small SECs after gene duplication, transforming constricted channels into wide opened ones and vice versa. Ancestral sequence reconstructions suggest that during the evolutionary emergence of RA signaling, the ancestral, narrow-channeled metazoan ALDH1/2 gave rise to large ALDH1 channels capable of accommodating bulky aldehydes, such as retinaldehyde, supporting the view that retinoid-dependent signaling arose from ancestral cellular detoxification mechanisms. Our analyses also indicate that, on a more restricted evolutionary scale, ALDH1 duplicates from invertebrate chordates (amphioxus and ascidian tunicates) underwent switches to smaller and narrower SECs. When combined with alterations in gene expression, these switches led to neofunctionalization from ALDH1-like roles in embryonic patterning to systemic, ALDH2-like roles, suggesting functional shifts from signaling to detoxification. PMID:21169504

  4. Structural shifts of aldehyde dehydrogenase enzymes were instrumental for the early evolution of retinoid-dependent axial patterning in metazoans

    Science.gov (United States)

    Sobreira, Tiago J. P.; Marlétaz, Ferdinand; Simões-Costa, Marcos; Schechtman, Deborah; Pereira, Alexandre C.; Brunet, Frédéric; Sweeney, Sarah; Pani, Ariel; Aronowicz, Jochanan; Lowe, Christopher J.; Davidson, Bradley; Laudet, Vincent; Bronner, Marianne; de Oliveira, Paulo S. L.; Schubert, Michael; Xavier-Neto, José

    2011-01-01

    Aldehyde dehydrogenases (ALDHs) catabolize toxic aldehydes and process the vitamin A-derived retinaldehyde into retinoic acid (RA), a small diffusible molecule and a pivotal chordate morphogen. In this study, we combine phylogenetic, structural, genomic, and developmental gene expression analyses to examine the evolutionary origins of ALDH substrate preference. Structural modeling reveals that processing of small aldehydes, such as acetaldehyde, by ALDH2, versus large aldehydes, including retinaldehyde, by ALDH1A is associated with small versus large substrate entry channels (SECs), respectively. Moreover, we show that metazoan ALDH1s and ALDH2s are members of a single ALDH1/2 clade and that during evolution, eukaryote ALDH1/2s often switched between large and small SECs after gene duplication, transforming constricted channels into wide opened ones and vice versa. Ancestral sequence reconstructions suggest that during the evolutionary emergence of RA signaling, the ancestral, narrow-channeled metazoan ALDH1/2 gave rise to large ALDH1 channels capable of accommodating bulky aldehydes, such as retinaldehyde, supporting the view that retinoid-dependent signaling arose from ancestral cellular detoxification mechanisms. Our analyses also indicate that, on a more restricted evolutionary scale, ALDH1 duplicates from invertebrate chordates (amphioxus and ascidian tunicates) underwent switches to smaller and narrower SECs. When combined with alterations in gene expression, these switches led to neofunctionalization from ALDH1-like roles in embryonic patterning to systemic, ALDH2-like roles, suggesting functional shifts from signaling to detoxification. PMID:21169504

  5. Amyloid/Melanin distinctive mark in invertebrate immunity

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    A Grimaldi

    2012-09-01

    Full Text Available Protostomes and Deuterostomes show the same nexus between melanin production, and amyloid fibril production, i.e., the presence of melanin is indissolubly linked to amyloid scaffold that, in turn, is conditioned by the redox status/cytoplasmic pH modification, pro-protein cleavage presence, adrenocorticotropin hormone (ACTH, melanocyte-stimulating hormone (α-MSH, and neutral endopeptidase (NEP overexpressions. These events represent the crucial component of immune response in invertebrates, while in vertebrates these series of occurrences could be interpreted as a modest and very restricted innate immune response. On the whole, it emerges that the mechanisms involving amyloid fibrils/pigment synthesis in phylogenetically distant metazoan (viz, cnidaria, molluscs, annelids, insects, ascidians and vertebrates are evolutionary conserved. Furthermore, our data show the relationship between immune and neuroendocrine systems in amyloid/melanin synthesis. Indeed the process is closely associated to ACTH-α-MSH production, and their role in stress responses leading to pigment production reflects and confirms again their ancient phylogeny.

  6. Pyridinoacridine alkaloids of marine origin: NMR and MS spectral data, synthesis, biosynthesis and biological activity

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    Louis P. Sandjo

    2015-09-01

    Full Text Available This review focuses on pyridoacridine-related metabolites as one biologically interesting group of alkaloids identified from marine sources. They are produced by marine sponges, ascidians and tunicates, and they are structurally comprised of four to eight fused rings including heterocycles. Acridine, acridone, dihydroacridine, and quinolone cores are features regularly found in these alkaloid skeletons. The lack of hydrogen atoms next to quaternary carbon atoms for two or three rings makes the chemical shift assignment a difficult task. In this regard, one of the aims of this review is the compilation of previously reported, pyridoacridine 13C NMR data. Observations have been made on the delocalization of electrons and the presence of some functional groups that lead to changes in the chemical shift of some carbon resonances. The lack of mass spectra information for these alkaloids due to the compactness of their structures is further discussed. Moreover, the biosynthetic pathways of some of these metabolites have been shown since they could inspire biomimetic synthesis. The synthesis routes used to prepare members of these marine alkaloids (as well as their analogues, which are synthesized for biological purposes are also discussed. Pyridoacridines were found to have a large spectrum of bioactivity and this review highlights and compares the pharmacophores that are responsible for the observed bioactivity.

  7. Climate change and glacier retreat drive shifts in an Antarctic benthic ecosystem.

    Science.gov (United States)

    Sahade, Ricardo; Lagger, Cristian; Torre, Luciana; Momo, Fernando; Monien, Patrick; Schloss, Irene; Barnes, David K A; Servetto, Natalia; Tarantelli, Soledad; Tatián, Marcos; Zamboni, Nadia; Abele, Doris

    2015-11-01

    The Antarctic Peninsula (AP) is one of the three places on Earth that registered the most intense warming in the last 50 years, almost five times the global mean. This warming has strongly affected the cryosphere, causing the largest ice-shelf collapses ever observed and the retreat of 87% of glaciers. Ecosystem responses, although increasingly predicted, have been mainly reported for pelagic systems. However, and despite most Antarctic species being benthic, responses in the Antarctic benthos have been detected in only a few species, and major effects at assemblage level are unknown. This is probably due to the scarcity of baselines against which to assess change. We performed repeat surveys of coastal benthos in 1994, 1998, and 2010, analyzing community structure and environmental variables at King George Island, Antarctica. We report a marked shift in an Antarctic benthic community that can be linked to ongoing climate change. However, rather than temperature as the primary factor, we highlight the resulting increased sediment runoff, triggered by glacier retreat, as the potential causal factor. The sudden shift from a "filter feeders-ascidian domination" to a "mixed assemblage" suggests that thresholds (for example, of tolerable sedimentation) and alternative equilibrium states, depending on the reversibility of the changes, could be possible traits of this ecosystem. Sedimentation processes will be increasing under the current scenario of glacier retreat, and attention needs to be paid to its effects along the AP. PMID:26702429

  8. Characteristics of the mesophotic megabenthic assemblages of the vercelli seamount (north tyrrhenian sea.

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    Marzia Bo

    Full Text Available The biodiversity of the megabenthic assemblages of the mesophotic zone of a Tyrrhenian seamount (Vercelli Seamount is described using Remotely Operated Vehicle (ROV video imaging from 100 m depth to the top of the mount around 61 m depth. This pinnacle hosts a rich coralligenous community characterized by three different assemblages: (i the top shows a dense covering of the kelp Laminaria rodriguezii; (ii the southern side biocoenosis is mainly dominated by the octocorals Paramuricea clavata and Eunicella cavolinii; while (iii the northern side of the seamount assemblage is colonized by active filter-feeding organisms such as sponges (sometimes covering 100% of the surface with numerous colonies of the ascidian Diazona violacea, and the polychaete Sabella pavonina. This study highlights, also for a Mediterranean seamount, the potential role of an isolated rocky peak penetrating the euphotic zone, to work as an aggregating structure, hosting abundant benthic communities dominated by suspension feeders, whose distribution may vary in accordance to the geomorphology of the area and the different local hydrodynamic conditions.

  9. Cyanobacteria in Coral Reef Ecosystems: A Review

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    L. Charpy

    2012-01-01

    Full Text Available Cyanobacteria have dominated marine environments and have been reef builders on Earth for more than three million years (myr. Cyanobacteria still play an essential role in modern coral reef ecosystems by forming a major component of epiphytic, epilithic, and endolithic communities as well as of microbial mats. Cyanobacteria are grazed by reef organisms and also provide nitrogen to the coral reef ecosystems through nitrogen fixation. Recently, new unicellular cyanobacteria that express nitrogenase were found in the open ocean and in coral reef lagoons. Furthermore, cyanobacteria are important in calcification and decalcification. All limestone surfaces have a layer of boring algae in which cyanobacteria often play a dominant role. Cyanobacterial symbioses are abundant in coral reefs; the most common hosts are sponges and ascidians. Cyanobacteria use tactics beyond space occupation to inhibit coral recruitment. Cyanobacteria can also form pathogenic microbial consortia in association with other microbes on living coral tissues, causing coral tissue lysis and death, and considerable declines in coral reefs. In deep lagoons, coccoid cyanobacteria are abundant and are grazed by ciliates, heteroflagellates, and the benthic coral reef community. Cyanobacteria produce metabolites that act as attractants for some species and deterrents for some grazers of the reef communities.

  10. Biochemical and toxicological evaluation of nano-heparins in cell functional properties, proteasome activation and expression of key matrix molecules.

    Science.gov (United States)

    Piperigkou, Zoi; Karamanou, Konstantina; Afratis, Nikolaos A; Bouris, Panagiotis; Gialeli, Chrysostomi; Belmiro, Celso L R; Pavão, Mauro S G; Vynios, Dimitrios H; Tsatsakis, Aristidis M

    2016-01-01

    The glycosaminoglycan heparin and its derivatives act strongly on blood coagulation, controlling the activity of serine protease inhibitors in plasma. Nonetheless, there is accumulating evidence highlighting different anticancer activities of these molecules in numerous types of cancer. Nano-heparins may have great biological significance since they can inhibit cell proliferation and invasion as well as inhibiting proteasome activation. Moreover, they can cause alterations in the expression of major modulators of the tumor microenvironment, regulating cancer cell behavior. In the present study, we evaluated the effects of two nano-heparin formulations: one isolated from porcine intestine and the other from the sea squirt Styela plicata, on a breast cancer cell model. We determined whether these nano-heparins are able to affect cell proliferation, apoptosis and invasion, as well as proteasome activity and the expression of extracellular matrix molecules. Specifically, we observed that nano-Styela compared to nano-Mammalian analogue has higher inhibitory role on cell proliferation, invasion and proteasome activity. Moreover, nano-Styela regulates cell apoptosis, expression of inflammatory molecules, such as IL-6 and IL-8 and reduces the expression levels of extracellular matrix macromolecules, such as the proteolytic enzymes MT1-MMP, uPA and the cell surface proteoglycans syndecan-1 and -2, but not on syndecan-4. The observations reported in the present article indicate that nano-heparins and especially ascidian heparin are effective agents for heparin-induced effects in critical cancer cell functions, providing an important possibility in pharmacological targeting. PMID:26476401

  11. A profile of the in vitro antitumor activity of lissoclinolide

    International Nuclear Information System (INIS)

    Lissoclinolide is a small non-nitrogenous lactone isolated from the marine ascidian Lissoclinum patella. Previous studies of lissoclinolide (isolated from a fungus and an actinomycete) have identified varying activity against both Gram-negative and Gram-positive bacteria. In this study, lissoclinolide was able to inhibit cell growth in various mammalian tumor lines at an average IC50 of 395 nM (determined by MTT conversion after 48-h treatment). Treatment of HCT 116 human colon tumor cells with 2.4 μM lissoclinolide resulted in a strong arrest in the G2/M phase of the cell cycle after 24-h exposure. A daughter cell line lacking p53 showed an identical response while there was a slight increase in cytotoxicity towards a p21 null cell line. Although treatment with 2.4 μM lissoclinolide did not result in apoptosis after 48 h, this arrest was not reversible when drug wash out was attempted. The mechanism of action does not appear to involve tubulin, ubiquitin-specific isopeptidases, p53 or p21. COMPARE analysis in the NCI 60 cell line tumor panel revealed a moderate selectivity towards colon tumor cell lines

  12. Forming a tough shell via an intracellular matrix and cellular junctions in the tail epidermis of Oikopleura dioica (Chordata: Tunicata: Appendicularia)

    Science.gov (United States)

    Nakashima, Keisuke; Nishino, Atsuo; Hirose, Euichi

    2011-08-01

    A postanal tail is a major synapomorphy of the phylum Chordata, which is composed of three subphyla: Vertebrata, Cephalochordata, and Tunicata (Urochordata). Among tunicates, appendicularians are the only group that retains the tail in the adult, and the adult tail functions in locomotion and feeding in combination with a cellulose-based house structure. Given the phylogenetic position of tunicates, the appendicularian adult tail may possess ancestral features of the chordate tail. We assess the ultrastructural development of the tail epidermis of the appendicularian Oikopleura dioica. The epidermis of the larval tail is enclosed by the larval envelope, which is a thin sheet similar to the outer tunic layer of ascidian larvae. The epidermis of the adult tail seems to bear no tunic-like cellulosic integuments, and the tail fin is a simple folding of the epidermis. Every epidermal cell, except for the triangular cells at the edge of the tail fin, has a conspicuous matrix layer of fibrous content in the apical cytoplasm without enclosing membranes. The epidermis of the larval tail does not have a fibrous matrix layer, suggesting the production of the layer during larval development and metamorphosis. Zonulae adhaerentes firmly bind the epidermal cells of the adult tail to one another, and the dense microfilaments lining the cell borders constitute a mechanical support for the cell membranes. The intracellular matrix, cell junctions, and cytoskeletons probably make the tail epidermis a tough, flexible shell supporting the active beating of the oikopleuran adult tail.

  13. Short-term post-mortality predation and scavenging and longer-term recovery after anoxia in the northern Adriatic Sea

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    M. Blasnig

    2013-03-01

    Full Text Available In the Mediterranean, the northern Adriatic Sea shows most features known to promote late-summer hypoxia and anoxia. These features, along with anthropogenic eutrophication and marine snow events, have led to repeated benthic mortalities here. The present study was designed to document the post-anoxia macrofauna dynamics. We deployed an underwater instrument to induce small-scale anoxia in situ (total area 0.5 m2. Two time-lapse camera deployments examined short-term scavenging of the moribund and dead organisms (multi-species clumps consisting of sponges and ascidians over a 3-day period (August 2008: 71.5 h, September 2008: 67.5 h. Longer-term recovery (2 yr in the same two plots was examined with an independent photo-series. Predators and scavengers arrived in a distinct sequence. The first to arrive were demersal (Gobius niger, Serranus hepatus and benthopelagic fishes (Diplodus vulgaris, Pagellus erythrinus, followed by hermit crabs (Paguristes eremita, showing a clear day/night rhythm in presence and gastropods (Hexaplex trunculus. This sequence of arrival is attributed to the relative speeds of the organisms and their densities. The scavengers remained in dense aggregations (e.g. up to 33 P. eremita individuals at one time as long as the dead organisms were available. The whole sessile fauna was largely removed or consumed within 7 (August plot and 13 (September plot days after anoxia. No macroepibenthic recovery took place in the experimental plots one and two years after anoxia. This study underlines the sensitivity of this soft-bottom community and supports calls for reducing additional anthropogenic disturbances such as damaging commercial fishing practices that impede recolonization and threaten benthic community structure and function over the long-term.

  14. The repertoire of G protein-coupled receptors in the sea squirt Ciona intestinalis

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    Manoj Narayanan

    2008-05-01

    Full Text Available Abstract Background G protein-coupled receptors (GPCRs constitute a large family of integral transmembrane receptor proteins that play a central role in signal transduction in eukaryotes. The genome of the protochordate Ciona intestinalis has a compact size with an ancestral complement of many diversified gene families of vertebrates and is a good model system for studying protochordate to vertebrate diversification. An analysis of the Ciona repertoire of GPCRs from a comparative genomic perspective provides insight into the evolutionary origins of the GPCR signalling system in vertebrates. Results We have identified 169 gene products in the Ciona genome that code for putative GPCRs. Phylogenetic analyses reveal that Ciona GPCRs have homologous representatives from the five major GRAFS (Glutamate, Rhodopsin, Adhesion, Frizzled and Secretin families concomitant with other vertebrate GPCR repertoires. Nearly 39% of Ciona GPCRs have unambiguous orthologs of vertebrate GPCR families, as defined for the human, mouse, puffer fish and chicken genomes. The Rhodopsin family accounts for ~68% of the Ciona GPCR repertoire wherein the LGR-like subfamily exhibits a lineage specific gene expansion of a group of receptors that possess a novel domain organisation hitherto unobserved in metazoan genomes. Conclusion Comparison of GPCRs in Ciona to that in human reveals a high level of orthology of a protochordate repertoire with that of vertebrate GPCRs. Our studies suggest that the ascidians contain the basic ancestral complement of vertebrate GPCR genes. This is evident at the subfamily level comparisons since Ciona GPCR sequences are significantly analogous to vertebrate GPCR subfamilies even while exhibiting Ciona specific genes. Our analysis provides a framework to perform future experimental and comparative studies to understand the roles of the ancestral chordate versions of GPCRs that predated the divergence of the urochordates and the vertebrates.

  15. Deep-water stands of Cystoseira zosteroides C. Agardh (Fucales, Ochrophyta) in the Northwestern Mediterranean: Insights into assemblage structure and population dynamics

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    Ballesteros, Enric; Garrabou, Joaquim; Hereu, Bernat; Zabala, Mikel; Cebrian, Emma; Sala, Enric

    2009-04-01

    Populations dominated by Cystoseira zosteroides, an endemic and threatened Mediterranean seaweed, colonize deep-water rocky habitats down to more than 50 m depth. Assemblages dominated by this species display high algal and invertebrate species richness. Algal biomass averages 1134 g dw m -2. Erect and turf algae account for only 25% of total algal dry weight, while encrusting corallines are responsible for the remaining 75%. Sponges, bryozoans and ascidians constitute the dominant sessile macrofauna. Cystoseira zosteroides is the dominant erect algae, with a mean biomass of 60.6 g dw m -2, and densities ranging from 4 to 7 plants m -2. The alien turf alga Womersleyella setacea has a biomass of 104.2 g dw m -2 and covers most of the understory substrate. The size-frequency distribution of C. zosteroides populations shows differences over time. Mean annual growth of the main axis is around 0.5 cm and mean annual mortality rate is lower than 2%. Recruitment was almost nil during the studied period of time (10 years). Processes structuring these deep-water Cystoseira stands must be driven by episodic disturbances, after-disturbance recruitment pulses, and long periods of steady growth that last at least 10 years. However, it is also possible that recruitment is irreversibly inhibited by the alien alga W. setacea in which case these old-growth stands are faced with extinction. The highly diversified assemblages and the low growth and low mortality rates of C. zosteroides indicate high vulnerability to natural and anthropogenic disturbances, and call for effective measures to ensure their conservation.

  16. A Tale of Two Drug Targets: The Evolutionary History of BACE1 and BACE2

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    Christopher eSouthan

    2013-12-01

    Full Text Available The beta amyloid (APP cleaving enzyme (BACE1 has been a drug target for Alzheimer's Disease (AD since 1999 with lead inhibitors now entering clinical trials. In 2011, the paralogue, BACE2, became a new target for type II diabetes (T2DM having been identified as a TMEM27 secretase regulating pancreatic β cell function. However, the normal roles of both enzymes are unclear. This study outlines their evolutionary history and new opportunities for functional genomics. We identified 30 homologues (UrBACEs in basal phyla including Placozoans, Cnidarians, Choanoflagellates, Porifera, Echinoderms, Annelids, Mollusks and Ascidians (but not Ecdysozoans. UrBACEs are predominantly single copy, show 35% to 45% protein sequence identity with mammalian BACE1, are approximately 100 residues longer than cathepsin paralogues with an aspartyl protease domain flanked by a signal peptide and a C-terminal transmembrane domain. While multiple paralogues in Trichoplax and Monosiga pre-date the nervous system, duplication of the UrBACE in fish gave rise to BACE1 and BACE2 in the vertebrate lineage. The latter evolved more rapidly as the former maintained the emergent neuronal role. In mammals, Ka/Ks for BACE2 is higher than BACE1 but low ratios for both suggest purifying selection. The 5’ exons show higher Ka/Ks than the catalytic section. Model organism genomes show the absence of certain BACE human substrates when the UrBACE is present. Experiments could thus reveal undiscovered substrates and roles. The human protease double-target status means that evolutionary trajectories and functional shifts associated with different substrates will have implications for the development of clinical candidates for both AD and T2DM. A rational basis for inhibition specificity ratios and assessing target-related side effects will be facilitated by a more complete picture of BACE1 and BACE2 functions informed by their evolutionary context.

  17. An efficient method to find potentially universal population genetic markers, applied to metazoans

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    Chenuil Anne

    2010-09-01

    Full Text Available Abstract Background Despite the impressive growth of sequence databases, the limited availability of nuclear markers that are sufficiently polymorphic for population genetics and phylogeography and applicable across various phyla restricts many potential studies, particularly in non-model organisms. Numerous introns have invariant positions among kingdoms, providing a potential source for such markers. Unfortunately, most of the few known EPIC (Exon Primed Intron Crossing loci are restricted to vertebrates or belong to multigenic families. Results In order to develop markers with broad applicability, we designed a bioinformatic approach aimed at avoiding multigenic families while identifying intron positions conserved across metazoan phyla. We developed a program facilitating the identification of EPIC loci which allowed slight variation in intron position. From the Homolens databases we selected 29 gene families which contained 52 promising introns for which we designed 93 primer pairs. PCR tests were performed on several ascidians, echinoderms, bivalves and cnidarians. On average, 24 different introns per genus were amplified in bilaterians. Remarkably, five of the introns successfully amplified in all of the metazoan genera tested (a dozen genera, including cnidarians. The influence of several factors on amplification success was investigated. Success rate was not related to the phylogenetic relatedness of a taxon to the groups that most influenced primer design, showing that these EPIC markers are extremely conserved in animals. Conclusions Our new method now makes it possible to (i rapidly isolate a set of EPIC markers for any phylum, even outside the animal kingdom, and thus, (ii compare genetic diversity at potentially homologous polymorphic loci between divergent taxa.

  18. Anti-Infective Potential of Marine Invertebrates and Seaweeds from the Brazilian Coast

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    Mario Steindel

    2013-05-01

    Full Text Available This manuscript describes the evaluation of anti-infective potential in vitro of organic extracts from nine sponges, one ascidian, two octocorals, one bryozoan, and 27 seaweed species collected along the Brazilian coast. Antimicrobial activity was tested against Staphylococcus aureus (ATCC 25923, Enterococcus faecalis (ATCC 29212, Pseudomonas aeruginosa (ATCC 27853, Escherichia coli (ATCC 25922 and Candida albicans (ATCC 10231 by the disk diffusion method. Antiprotozoal activity was evaluated against Leishmania braziliensis (MHOM/BR/96/LSC96-H3 promastigotes and Trypanosoma cruzi (MHOM/BR/00/Y epimastigotes by MTT assay. Activity against intracellular amastigotes of T. cruzi and L. brasiliensis in murine macrophages was also evaluated. Antiviral activity was tested against Herpes Simplex Virus type 1 (HSV-1, KOS strain by the plaque number reduction assay (IC50. Cytotoxicity on VERO cells was evaluated by the MTT assay (CC50. The results were expressed as SI = CC50/IC50. The most promising antimicrobial results were obtained against S. aureus and C. albicans with Dragmacidon reticulatum. Among the seaweeds, only Osmundaria obtusiloba showed moderate activity against P. aeruginosa. Concerning antiprotozoal activity, Bugula neritina, Carijoa riseii, Dragmaxia anomala and Haliclona (Halichoclona sp. showed the most interesting results, mainly against extracellular promastigote forms of L. braziliensis (66, 35.9, 97.2, and 43.6% inhibition, respectively. Moreover, six species of seaweeds Anadyomene saldanhae, Caulerpa cupressoides, Canistrocarpus cervicornis, Dictyota sp., Ochtodes secundiramea, and Padina sp. showed promising results against L. braziliensis (87.9, 51.7, 85.9, 93.3, 99.7, and 80.9% inhibition, respectively, and only Dictyota sp. was effective against T. cruzi (60.4% inhibition. Finally, the antiherpes activity was also evaluated, with Haliclona (Halichoclona sp. and Petromica citrina showing the best results (SI = 11.9 and SI > 5

  19. New Mediterranean Biodiversity Records (October, 2014

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    S. KATSANEVAKIS

    2014-09-01

    Full Text Available The Collective Article ‘New Mediterranean Biodiversity Records’ of the Mediterranean Marine Science journal offers the means to publish biodiversity records in the Mediterranean Sea. The current article is divided in two parts, for records of alien and native species respectively. The new records of alien species include: the red alga Asparagopsis taxiformis (Crete and Lakonicos Gulf (Greece; the red alga Grateloupia turuturu (along the Israeli Mediterranean shore; the mantis shrimp Clorida albolitura (Gulf of Antalya, Turkey; the mud crab Dyspanopeus sayi (Mar Piccolo of Taranto, Ionian Sea; the blue crab Callinectes sapidus (Chios Island, Greece; the isopod Paracerceis sculpta (northern Aegean Sea, Greece; the sea urchin Diadema setosum (Gökova Bay, Turkey; the molluscs Smaragdia souverbiana, Murex forskoehlii, Fusinus verrucosus, Circenita callipyga, and Aplysia dactylomela (Syria; the cephalaspidean mollusc Haminoea cyanomarginata (Baia di Puolo, Massa Lubrense, Campania, southern Italy; the topmouth gudgeon Pseudorasbora parva (Civitavecchia, Tyrrhenian Sea; the fangtooth moray Enchelycore anatine (Plemmirio marine reserve, Sicily; the silver-cheeked toadfish Lagocephalus sceleratus (Saros Bay, Turkey; and Ibiza channel, Spain; the Indo-Pacific ascidian Herdmania momusin Kastelorizo Island (Greece; and the foraminiferal Clavulina multicam erata (Saronikos Gulf, Greece. The record of L. sceleratus in Spain consists the deepest (350-400m depth record of the species in the Mediterranean Sea. The new records of native species include: first record of the ctenophore Cestum veneris in Turkish marine waters; the presence of Holothuria tubulosa and Holothuria polii in the Bay of Igoumenitsa (Greece; the first recorded sighting of the bull ray Pteromylaeus bovinus in Maltese waters; and a new record of the fish Lobotes surinamensis from Maliakos Gulf. 

  20. Tough adults, frail babies: an analysis of stress sensitivity across early life-history stages of widely introduced marine invertebrates.

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    M Carmen Pineda

    Full Text Available All ontogenetic stages of a life cycle are exposed to environmental conditions so that population persistence depends on the performance of both adults and offspring. Most studies analysing the influence of abiotic conditions on species performance have focussed on adults, while studies covering early life-history stages remain rare. We investigated the responses of early stages of two widely introduced ascidians, Styela plicata and Microcosmus squamiger, to different abiotic conditions. Stressors mimicked conditions in the habitats where both species can be found in their distributional ranges and responses were related to the selection potential of their populations by analysing their genetic diversity. Four developmental stages (egg fertilisation, larval development, settlement, metamorphosis were studied after exposure to high temperature (30°C, low salinities (26 and 22‰ and high copper concentrations (25, 50 and 100 µg/L. Although most stressors effectively led to failure of complete development (fertilisation through metamorphosis, fertilisation and larval development were the most sensitive stages. All the studied stressors affected the development of both species, though responses differed with stage and stressor. S. plicata was overall more resistant to copper, and some stages of M. squamiger to low salinities. No relationship was found between parental genetic composition and responses to stressors. We conclude that successful development can be prevented at several life-history stages, and therefore, it is essential to consider multiple stages when assessing species' abilities to tolerate stress. Moreover, we found that early development of these species cannot be completed under conditions prevailing where adults live. These populations must therefore recruit from elsewhere or reproduce during temporal windows of more benign conditions. Alternatively, novel strategies or behaviours that increase overall reproductive success

  1. Tolerance of sponge assemblages to temperature anomalies: resilience and proliferation of sponges following the 1997-8 El-Nino southern oscillation.

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    Francisco Kelmo

    Full Text Available Coral reefs across the world are under threat from a range of stressors, and while there has been considerable focus on the impacts of these stressors on corals, far less is known about their effect on other reef organisms. The 1997-8 El-Niño Southern Oscillation (ENSO had notable and severe impacts on coral reefs worldwide, but not all reef organisms were negatively impacted by this large-scale event. Here we describe how the sponge fauna at Bahia, Brazil was influenced by the 1997-8 ENSO event. Sponge assemblages from three contrasting reef habitats (reef tops, walls and shallow banks at four sites were assessed annually from 1995 to 2011. The within-habitat sponge diversity did not vary significantly across the study period; however, there was a significant increase in density in all habitats. Multivariate analyses revealed no significant difference in sponge assemblage composition (ANOSIM between pre- and post-ENSO years for any of the habitats, suggesting that neither the 1997-8 nor any subsequent smaller ENSO events have had any measurable impact on the reef sponge assemblage. Importantly, this is in marked contrast to the results previously reported for a suite of other taxa (including corals, echinoderms, bryozoans, and ascidians, which all suffered mass mortalities as a result of the ENSO event. Our results suggest that of all reef taxa, sponges have the potential to be resilient to large-scale thermal stress events and we hypothesize that sponges might be less affected by projected increases in sea surface temperature compared to other major groups of reef organisms.

  2. Histamine Stimulates Ciliary Beat Frequency via the H2 Receptor in the Protochordate Botryllus schlosseri.

    Science.gov (United States)

    Cima, Francesca; Franchi, Nicola

    2016-05-01

    Histamine is a biogenic molecule that plays a role in many physiological pathways via binding to a specific receptor. Histaminergic receptors belong to the large family of seven-transmembrane α-helix domain receptors classified in mammals into four distinct classes: H1, H2, H3, and H4. Despite being widely studied in vertebrates, few data are available on the invertebrate receptors, with only predicted H1 and H2 sequences for nonchordate deuterostomes. Here, we report the first characterized transcript sequence for an H2 receptor from the colonial ascidian Botryllus schlosseri, describing the localization of both transcript and protein during blastogenic development through in situ hybridization and immunohistochemistry. Its phylogenetic relationships with deuterostome orthologous proteins are reported, its role in ciliary beat frequency (CBF) in cultured stigma cells of the branchial basket is outlined, and the effects of histamine and its receptor agonists and antagonists are analyzed. In the presence of increasing concentrations of histamine in the medium, CBF increases similarly to the selective H2 receptor agonist dimaprit. In contrast, ranitidine, which is an inhibitor of the H2 receptor, causes a significant inhibition of CBF, similar to that observed after preincubation with the specific anti-BsHRH2 or the anti-human HRH2 antibody. In cells bordering the branchial basket stigmata, both antibodies colocalize in the proximal region of the ciliary plasmalemma, and histamine is present inside vesicles of the apical region, thus supporting the hypothesis of a histamine-binding H2 receptor control of the pharyngeal mucociliary transport similar to that of the upper respiratory tract and middle ear in mammals. PMID:27139577

  3. Carbonate production and deposition in a warm-temperate macroalgal environment, Investigator Strait, South Australia

    Science.gov (United States)

    James, Noel P.; Bone, Yvonne

    2011-08-01

    The prolific macroalgal forests in shallow (red algae that are grazed by herbivorous gastropods, 2) an intermediate, 5-20 cm-high community of fleshy red algae, and 3) a 20-100 cm+-high canopy of large phaeophytes (especially Ecklonia, Cystophora and Xiophora) whose blades are locally encrusted with bryozoans, such as Membranipora membranacea, and spirorbids. Concealed surfaces of subvertical rock walls and cryptic habitats behind the macroalgal curtain have two tiers; 1) a cornucopia of encrusting plants and animals, especially crustose and geniculate corallines in shallow water, that give way in water depths > 4 m to numerous bryozoans (especially fenestrates), serpulid worms, numerous and diverse demosponges, ascidians, small solitary corals, epifaunal echinoids, and gastropods, and 2) a veil of macroalgae (mainly Cystophora and Ecklonia) that drapes down and shades the rock walls. Most carbonate sediment production does not come from calcareous epiphytes on the macroalgae but comes from the coralline algae and calcareous invertebrates living on the rock walls and in concealed depressions. Mollusks (gastropods and bivalves) and geniculate coralline algae with numerous lithoclasts, crustose coralline fragments, barnacle plates, serpulid worms, bryozoans, and large benthic foraminifers (especially Amphistegina) dominate the resultant gravels and sands; but there is little or no mud. This is because carbonate sediment is the result of production not only in the macrophyte factory but also in adjacent seagrass factories. Particles produced in the macroalgal factory are shed onto the adjacent seafloor, where they form the requisite sandy substrates for quick colonization by seagrasses. Thus, over time the sediment in this shallow but hydrodynaically energetic environment becomes a mixture of materials from the two sources with seagrasses contributing gastropods, large benthic foraminifers, spirorbids, bryozoans and articulated corallines to the sediment milieu. If

  4. Discovery and Evaluation of Thiazinoquinones as Anti-Protozoal Agents

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    Marcel Kaiser

    2013-09-01

    Full Text Available Pure compound screening has identified the dioxothiazino-quinoline-quinone ascidian metabolite ascidiathiazone A (2 to be a moderate growth inhibitor of Trypanosoma brucei rhodesiense (IC50 3.1 μM and Plasmodium falciparum (K1 dual drug resistant strain (IC50 3.3 μM while exhibiting low levels of cytotoxicity (L6, IC50 167 μM. A series of C-7 amide and Δ2(3 analogues were prepared that explored the influence of lipophilicity and oxidation state on observed anti-protozoal activity and selectivity. Little variation in anti-malarial potency was observed (IC50 0.62–6.5 μM, and no correlation was apparent between anti-malarial and anti-T. brucei activity. Phenethylamide 7e and Δ2(3-glycine analogue 8k exhibited similar anti-Pf activity to 2 but with slightly enhanced selectivity (SI 72 and 93, respectively, while Δ2(3-phenethylamide 8e (IC50 0.67 μM, SI 78 exhibited improved potency and selectivity towards T. brucei rhodesiense compared to the natural product hit. A second series of analogues were prepared that replaced the quinoline ring of 2 with benzofuran or benzothiophene moieties. While esters 10a/10b and 15 were once again found to exhibit cytotoxicity, carboxylic acid analogues exhibited potent anti-Pf activity (IC50 0.34–0.035 μM combined with excellent selectivity (SI 560–4000. In vivo evaluation of a furan carboxylic acid analogue against P. berghei was undertaken, demonstrating 85.7% and 47% reductions in parasitaemia with ip or oral dosing respectively.

  5. Cell signaling and transcription factor genes expressed during whole body regeneration in a colonial chordate

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    Rinkevich Baruch

    2008-10-01

    Full Text Available Abstract Background The restoration of adults from fragments of blood vessels in botryllid ascidians (termed whole body regeneration [WBR] represents an inimitable event in the chordates, which is poorly understood on the mechanistic level. Results To elucidate mechanisms underlying this phenomenon, a subtracted EST library for early WBR stages was previously assembled, revealing 76 putative genes belonging to major signaling pathways, including Notch/Delta, JAK/STAT, protein kinases, nuclear receptors, Ras oncogene family members, G-Protein coupled receptor (GPCR and transforming growth factor beta (TGF-β signaling. RT-PCR on selected transcripts documented specific up-regulation in only regenerating fragments, pointing to a broad activation of these signaling pathways at onset of WBR. The followed-up expression pattern of seven representative transcripts from JAK/STAT signaling (Bl-STAT, the Ras oncogene family (Bl-Rap1A, Bl-Rab-33, the protein kinase family (Bl-Mnk, Bl-Cnot, Bl-Slit and Bl-Bax inhibitor, revealed systemic and site specific activations during WBR in a sub-population of circulatory cells. Conclusion WBR in the non-vertebrate chordate Botrylloides leachi is a multifaceted phenomenon, presided by a complex array of cell signaling and transcription factors. Above results, provide a first insight into the whole genome molecular machinery of this unique regeneration process, and reveal the broad participation of cell signaling and transcription factors in the process. While regeneration involves the participation of specific cell populations, WBR signals are systemically expressed at the organism level.

  6. Morphological Differences between Larvae of the Ciona intestinalis Species Complex: Hints for a Valid Taxonomic Definition of Distinct Species.

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    Roberta Pennati

    Full Text Available The cosmopolitan ascidian Ciona intestinalis is the most common model species of Tunicata, the sister-group of Vertebrata, and widely used in developmental biology, genomics and evolutionary studies. Recently, molecular studies suggested the presence of cryptic species hidden within the C. intestinalis species, namely C. intestinalis type A and type B. So far, no substantial morphological differences have been identified between individuals belonging to the two types. Here we present morphometric, immunohistochemical, and histological analyses, as well as 3-D reconstructions, of late larvae obtained by cross-fertilization experiments of molecularly determined type A and type B adults, sampled in different seasons and in four different localities. Our data point to quantitative and qualitative differences in the trunk shape of larvae belonging to the two types. In particular, type B larvae exhibit a longer pre-oral lobe, longer and relatively narrower total body length, and a shorter ocellus-tail distance than type A larvae. All these differences were found to be statistically significant in a Discriminant Analysis. Depending on the number of analyzed parameters, the obtained discriminant function was able to correctly classify > 93% of the larvae, with the remaining misclassified larvae attributable to the existence of intra-type seasonal variability. No larval differences were observed at the level of histology and immunohistochemical localization of peripheral sensory neurons. We conclude that type A and type B are two distinct species that can be distinguished on the basis of larval morphology and molecular data. Since the identified larval differences appear to be valid diagnostic characters, we suggest to raise both types to the rank of species and to assign them distinct names.

  7. Morphological Differences between Larvae of the Ciona intestinalis Species Complex: Hints for a Valid Taxonomic Definition of Distinct Species

    Science.gov (United States)

    Pennati, Roberta; Ficetola, Gentile Francesco; Brunetti, Riccardo; Caicci, Federico; Gasparini, Fabio; Griggio, Francesca; Sato, Atsuko; Stach, Thomas; Kaul-Strehlow, Sabrina; Gissi, Carmela; Manni, Lucia

    2015-01-01

    The cosmopolitan ascidian Ciona intestinalis is the most common model species of Tunicata, the sister-group of Vertebrata, and widely used in developmental biology, genomics and evolutionary studies. Recently, molecular studies suggested the presence of cryptic species hidden within the C. intestinalis species, namely C. intestinalis type A and type B. So far, no substantial morphological differences have been identified between individuals belonging to the two types. Here we present morphometric, immunohistochemical, and histological analyses, as well as 3-D reconstructions, of late larvae obtained by cross-fertilization experiments of molecularly determined type A and type B adults, sampled in different seasons and in four different localities. Our data point to quantitative and qualitative differences in the trunk shape of larvae belonging to the two types. In particular, type B larvae exhibit a longer pre-oral lobe, longer and relatively narrower total body length, and a shorter ocellus-tail distance than type A larvae. All these differences were found to be statistically significant in a Discriminant Analysis. Depending on the number of analyzed parameters, the obtained discriminant function was able to correctly classify > 93% of the larvae, with the remaining misclassified larvae attributable to the existence of intra-type seasonal variability. No larval differences were observed at the level of histology and immunohistochemical localization of peripheral sensory neurons. We conclude that type A and type B are two distinct species that can be distinguished on the basis of larval morphology and molecular data. Since the identified larval differences appear to be valid diagnostic characters, we suggest to raise both types to the rank of species and to assign them distinct names. PMID:25955391

  8. Ultrastructure, molecular phylogenetics, and chlorophyll a content of novel cyanobacterial symbionts in temperate sponges.

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    Erwin, Patrick M; López-Legentil, Susanna; Turon, Xavier

    2012-10-01

    Marine sponges often harbor photosynthetic symbionts that may enhance host metabolism and ecological success, yet little is known about the factors that structure the diversity, specificity, and nature of these relationships. Here, we characterized the cyanobacterial symbionts in two congeneric and sympatric host sponges that exhibit distinct habitat preferences correlated with irradiance: Ircinia fasciculata (higher irradiance) and Ircinia variabilis (lower irradiance). Symbiont composition was similar among hosts and dominated by the sponge-specific cyanobacterium Synechococcus spongiarum. Phylogenetic analyses of 16S-23S rRNA internal transcribed spacer (ITS) gene sequences revealed that Mediterranean Ircinia spp. host a specific, novel symbiont clade ("M") within the S. spongiarum species complex. A second, rare cyanobacterium related to the ascidian symbiont Synechocystis trididemni was observed in low abundance in I. fasciculata and likewise corresponded to a new symbiont clade. Symbiont communities in I. fasciculata exhibited nearly twice the chlorophyll a concentrations of I. variabilis. Further, S. spongiarum clade M symbionts in I. fasciculata exhibited dense intracellular aggregations of glycogen granules, a storage product of photosynthetic carbon assimilation rarely observed in I. variabilis symbionts. In both host sponges, S. spongiarum cells were observed interacting with host archeocytes, although the lower photosynthetic activity of Cyanobacteria in I. variabilis suggests less symbiont-derived nutritional benefit. The observed differences in clade M symbionts among sponge hosts suggest that ambient irradiance conditions dictate symbiont photosynthetic activity and consequently may mediate the nature of host-symbiont relationships. In addition, the plasticity exhibited by clade M symbionts may be an adaptive attribute that allows for flexibility in host-symbiont interactions across the seasonal fluctuations in light and temperature characteristic of

  9. Biomixing generated by benthic filter feeders: a diffusion model for near-bottom phytoplankton depletion

    Science.gov (United States)

    Larsena, Poul S.; Riisgård, Hans Ulrik

    1997-05-01

    Transient concentration distributions of flagellate cells ( Rhodomonas sp.) previously measured by Riisgård and co-workers in laboratory experiments have been examined to develop a diffusion model for the process of phytoplankton depletion in stagnant seawater above populations of benthic filter feeders, the polychaete Nereis diversicolor and the ascidian Ciona intestinalis, respectively. The model is based on sinks located at inhalant openings and Fick's law with an effective diffusivity that decreases with distance above the bottom due to the biomixing generated by exhalant and inhalant feeding currents. For N. diversicolor, having inhalant and exhalant openings flush with the sediment surface and a moderate exhalant jet velocity of ˜0.01 m s -1, concentration boundary layer growth is retarded and limited by the low values of diffusivity prevailing at heights greater >˜0.05 m above the bottom. For C. intestinalis, having inhalant and exhalant openings situated ˜0.05-0.1 m above the bottom and a higher and inclined exhalant jet velocity of ˜0.1-0.2 m s -1, the concentration distributions show a nearly uniform depletion over a layer reaching a thickness of 0.2-0.3 m above the bottom due to high biomixing in this layer. Numerical predictions of concentration distributions reproduce essential features of experiments, and suggest near-bottom values of effective diffusivity of 0.3 x 10 -6 and 150 x 10 -6 m 2 s -1, for N. diversicolor and C. intestinalis, respectively. It is suggested that the latter value is so large that the induced mixing should be accounted for in modelling benthic concentration boundary layers under flow conditions.

  10. A single and rapid calcium wave at egg activation in Drosophila

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    Anna H. York-Andersen

    2015-03-01

    Full Text Available Activation is an essential process that accompanies fertilisation in all animals and heralds major cellular changes, most notably, resumption of the cell cycle. While activation involves wave-like oscillations in intracellular Ca2+ concentration in mammals, ascidians and polychaete worms and a single Ca2+ peak in fish and frogs, in insects, such as Drosophila, to date, it has not been shown what changes in intracellular Ca2+ levels occur. Here, we utilise ratiometric imaging of Ca2+ indicator dyes and genetically encoded Ca2+ indicator proteins to identify and characterise a single, rapid, transient wave of Ca2+ in the Drosophila egg at activation. Using genetic tools, physical manipulation and pharmacological treatments we demonstrate that the propagation of the Ca2+ wave requires an intact actin cytoskeleton and an increase in intracellular Ca2+ can be uncoupled from egg swelling, but not from progression of the cell cycle. We further show that mechanical pressure alone is not sufficient to initiate a Ca2+ wave. We also find that processing bodies, sites of mRNA decay and translational regulation, become dispersed following the Ca2+ transient. Based on this data we propose the following model for egg activation in Drosophila: exposure to lateral oviduct fluid initiates an increase in intracellular Ca2+ at the egg posterior via osmotic swelling, possibly through mechano-sensitive Ca2+ channels; a single Ca2+ wave then propagates in an actin dependent manner; this Ca2+ wave co-ordinates key developmental events including resumption of the cell cycle and initiation of translation of mRNAs such as bicoid.

  11. Population genetics features for persistent, but transient, Botryllus schlosseri (Urochordata) congregations in a central Californian marina.

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    Karahan, Arzu; Douek, Jacob; Paz, Guy; Rinkevich, Baruch

    2016-08-01

    The colonial tunicate Botryllus schlosseri is a globally distributed, invasive ascidian that has colonized the Californian coasts of the USA during the mid-late 1940s and has, since the late 1980s, spread north to Washington. This study analyzes the population genetic characteristics of transient populations residing at the Elkhorn Yacht-Club (EYC), in central California (seven sessions, 1996-2008), which suffered periodic catastrophes caused by episodic fresh-water floods and a single sampling session (in the year 2001) of five West-Coast populations using the mtDNA COI gene and five microsatellite markers. EYC microsatellite results were further compared with the closely situated but persistent population of the Santa Cruz Harbor (SCH) to understand the impact on EYC population regeneration processes after the 2005-flood catastrophe. All microsatellites were highly polymorphic, revealing a large number of unique alleles at different sampling dates. Whereas pairwise θ did not reveal significant differences between the EYC time-series samplings, the overall θ was significant, as it was between all the 2001 West Coast populations. The most likely cluster number was 3 for the EYC samples whereas two K values were obtained (2 and 5) for the 2001 samples. Tajima's D and Fu's/Fs tests did not reject the null hypothesis for COI neutral evolution, except for in the EYC-2000, 2007 and two 2001 samplings. The wide geographical range of the analyses has indicated that following the EYC 2005-flood catastrophe, newcomers could have originated from neighboring populations, from deep-water colonies that may have escaped the 2005 low salinity event, or less expectedly, from far away West-Coast populations, while revealing that the SCH population is the most probable source for the EYC population. PMID:27154209

  12. A glycine receptor is involved in the organization of swimming movements in an invertebrate chordate

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    Okamura Yasushi

    2010-01-01

    Full Text Available Abstract Background Rhythmic motor patterns for locomotion in vertebrates are generated in spinal cord neural networks known as spinal Central Pattern Generators (CPGs. A key element in pattern generation is the role of glycinergic synaptic transmission by interneurons that cross the cord midline and inhibit contralaterally-located excitatory neurons. The glycinergic inhibitory drive permits alternating and precisely timed motor output during locomotion such as walking or swimming. To understand better the evolution of this system we examined the physiology of the neural network controlling swimming in an invertebrate chordate relative of vertebrates, the ascidian larva Ciona intestinalis. Results A reduced preparation of the larva consisting of nerve cord and motor ganglion generates alternating swimming movements. Pharmacological and genetic manipulation of glycine receptors shows that they are implicated in the control of these locomotory movements. Morphological molecular techniques and heterologous expression experiments revealed that glycine receptors are inhibitory and are present on both motoneurones and locomotory muscle while putative glycinergic interneurons were identified in the nerve cord by labeling with an anti-glycine antibody. Conclusions In Ciona intestinalis, glycine receptors, glycinergic transmission and putative glycinergic interneurons, have a key role in coordinating swimming movements through a simple CPG that is present in the motor ganglion and nerve cord. Thus, the strong association between glycine receptors and vertebrate locomotory networks may now be extended to include the phylum chordata. The results suggest that the basic network for 'spinal-like' locomotion is likely to have existed in the common ancestor of extant chordates some 650 M years ago.

  13. In vivo antithrombotic properties of a heparin from the oocyte test cells of the sea squirt Styela plicata(Chordata-Tunicata

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    L. Cardilo-Reis

    2006-11-01

    Full Text Available In the ascidian Styela plicata, the oocytes are surrounded by two types of accessory cells named follicle cells and test cells. A heparin-like substance with an anticoagulant activity equivalent to 10% of mammalian heparin and about 5% as potent as the mammalian counterpart for the inhibition of thrombin by antithrombin was isolated from the oocyte test cells. In the present study, we compared the antithrombotic and hemorrhagic effects of sea squirt oocyte test cell heparin with those of porcine heparin in rat models of venous thrombosis and blood loss. Intravenous administration of the oocyte test cell heparin to Wistar rats (both sexes, weighing ~300 g, N = 4 in each group at a dose of 5.0 mg/kg body weight, which produced a 1.8-fold increase in plasma activated partial thromboplastin time, inhibited thrombosis by 45 ± 13.5% (mean ± SD without any bleeding effect. The same dose of porcine heparin inhibited thrombosis by 100 ± 1.4%, but produced a blood loss three times greater than that of the saline-treated control. However, 10-fold reduction of the dose of porcine heparin to 0.5 mg/kg body weight, which produced a 5-fold increase in plasma-activated partial thromboplastin time, inhibited thrombosis by 70 ± 13% without any bleeding effect. The antithrombotic properties of a new heparin isolated from test cells of the sea squirt S. plicata, reported here for the first time, indicate that, although sea squirt oocyte test cell heparin was a poor anticoagulant compared to porcine heparin, it had a significant antithrombotic effect without causing bleeding.

  14. A review of contemporary patterns of endemism for shallow water reef fauna in the Red Sea

    KAUST Repository

    DiBattista, Joseph

    2015-11-03

    Aim The Red Sea is characterised by a unique fauna and historical periods of desiccation, hypersalinity and intermittent isolation. The origin and contemporary composition of reef-associated taxa in this region can illuminate biogeographical principles about vicariance and the establishment (or local extirpation) of existing species. Here we aim to: (1) outline the distribution of shallow water fauna between the Red Sea and adjacent regions, (2) explore mechanisms for maintaining these distributions and (3) propose hypotheses to test these mechanisms. Location Red Sea, Gulf of Aden, Arabian Sea, Arabian Gulf and Indian Ocean. Methods Updated checklists for scleractinian corals, fishes and non-coral invertebrates were used to determine species richness in the Red Sea and the rest of the Arabian Peninsula and assess levels of endemism. Fine-scale diversity and abundance of reef fishes within the Red Sea were explored using ecological survey data. Results Within the Red Sea, we recorded 346 zooxanthellate and azooxanthellate scleractinian coral species of which 19 are endemic (5.5%). Currently 635 species of polychaetes, 211 echinoderms and 79 ascidians have been documented, with endemism rates of 12.6%, 8.1% and 16.5% respectively. A preliminary compilation of 231 species of crustaceans and 137 species of molluscs include 10.0% and 6.6% endemism respectively. We documented 1071 shallow fish species, with 12.9% endemic in the entire Red Sea and 14.1% endemic in the Red Sea and Gulf of Aden. Based on ecological survey data of endemic fishes, there were no major changes in species richness or abundance across 1100 km of Saudi Arabian coastline. Main conclusions The Red Sea biota appears resilient to major environmental fluctuations and is characterized by high rates of endemism with variable degrees of incursion into the Gulf of Aden. The nearby Omani and Arabian Gulfs also have variable environments and high levels of endemism, but these are not consistently distinct

  15. The fester locus in Botryllus schlosseri experiences selection

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    Nydam Marie L

    2012-12-01

    Full Text Available Abstract Background Allorecognition, the ability of an organism to distinguish self from non-self, occurs throughout the entire tree of life. Despite the prevalence and importance of allorecognition systems, the genetic basis of allorecognition has rarely been characterized outside the well-known MHC (Major Histocompatibility Complex in vertebrates and SI (Self-Incompatibility in plants. Where loci have been identified, their evolutionary history is an open question. We have previously identified the genes involved in self/non-self recognition in the colonial ascidian Botryllus schlosseri, and we can now begin to investigate their evolution. In B. schlosseri, colonies sharing 1 or more alleles of a gene called FuHC (Fusion Histocompatibility will fuse. Protein products of a locus called fester, located ~300 kb from FuHC, have been shown to play multiple roles in the histocompatibility reaction, as activating and/or inhibitory receptors. We test whether the proteins encoded by this locus are evolving neutrally or are experiencing balancing, directional, or purifying selection. Results Nearly all of the variation in the fester locus resides within populations. The 13 housekeeping genes (12 nuclear genes and mitochondrial cytochrome oxidase I have substantially more structure among populations within groups and among groups than fester. All polymorphism statistics (Tajima's D, Fu and Li's D* and F* are significantly negative for the East Coast A-type alleles, and Fu and Li's F* statistic is significantly negative for the West Coast A-type alleles. These results are likely due to selection rather than demography, given that 10 of the housekeeping loci have no populations with significant values for any of the polymorphism statistics. The majority of codons in the fester proteins have ω values 95% posterior probability of ω values > 1. Conclusion Fester proteins are evolving non-neutrally. The polymorphism statistics are consistent with either

  16. Differential responses of emergent intertidal coral reef fauna to a large-scale El-Niño southern oscillation event: sponge and coral resilience.

    Science.gov (United States)

    Kelmo, Francisco; Bell, James J; Moraes, Simone Souza; Gomes, Rilza da Costa Tourinho; Mariano-Neto, Eduardo; Attrill, Martin J

    2014-01-01

    There is a paucity of information on the impacts of the 1997-8 El Niño event and subsequent climatic episodes on emergent intertidal coral reef assemblages. Given the environmental variability intertidal reefs experience, such reefs may potentially be more resilient to climatic events and provide important insights into the adaptation of reef fauna to future ocean warming. Here we report the results of a 17-year (1995-2011) biodiversity survey of four emergent coral reef ecosystems in Bahia, Brazil, to assess the impact of a major El Niño event on the reef fauna, and determine any subsequent recovery. The densities of two species of coral, Favia gravida and Siderastrea stellata, did not vary significantly across the survey period, indicating a high degree of tolerance to the El Niño associated stress. However, there were marked decreases in the diversity of other taxa. Molluscs, bryozoans and ascidians suffered severe declines in diversity and abundance and had not recovered to pre-El Niño levels by the end of the study. Echinoderms were reduced to a single species in 1999, Echinometra lucunter, although diversity levels had recovered by 2002. Sponge assemblages were not impacted by the 1997-8 event and their densities had increased by the study end. Multivariate analysis indicated that a stable invertebrate community had re-established on the reefs after the El Niño event, but it has a different overall composition to the pre-El Niño community. It is unclear if community recovery will continue given more time, but our study highlights that any increase in the frequency of large-scale climatic events to more than one a decade is likely to result in a persistent lower-diversity state. Our results also suggest some coral and sponge species are particularly resilient to the El Niño-associated stress and therefore represent suitable models to investigate temperature adaptation in reef organisms. PMID:24675785

  17. Hemichordates and the Origin of Chordates

    Science.gov (United States)

    Gerhart, John; Kirschner, Marc; Lowe, Chris

    2002-01-01

    At the start of the period of the NASA grant three years ago, we had no information on the organization and development of the body axis of the hemichordate, Saccoglossus kowalevskii. Now we have substantial findings about the anteroposterior axis and dorsoventral axis, and based on this information, we have new insights about the origin of chordates from ancestral deuterostomes. We found ways to obtain and preserve large numbers of embryos and hatched juveniles. We can now collect about 40,000 embryos in the month of September, the time of S. kowalevskii spawning at Woods Hole. Excellent cDNA libraries were prepared from three developmental stages. From these libraries, we directly isolated about 30 gene ortholog sequences by screening and pcr techniques, all of these sequences of interest in the inquiry about the animal's organization and development. We also performed a mid-sized EST project (60,000 randomly picked clones, many of these arrayed). About half of these have been analyzed so far by blastx and are suitable for direct use of clones. We have obtained about 50 interesting sequences from this set. The rest still await analysis. Thus, at this time we have isolated orthologs of 80 genes that are known to be expressed in chordates in conserved domains and known to have interesting roles in chordate organization and development. The orthology of the S. kowalevskii sequences has been verified by neighbor joining and parsimony methods, with bootstrap estimates of validity. The S. kowalevskii sequences cluster with other deuterostome sequences, namely, other hemichordates, echinoderms, ascidians, amphioxus, or vertebrates, depending on what sequences are available in the database for comparison. We have used these sequences to do high quality in situ hybridization on S. kowalevskii embryos, and the results can be divided into three sections-those concerning the anteroposterior axis of S. kowalevskii in comparison to the same axis of chordates, those concerning

  18. Reproductive protein evolution in two cryptic species of marine chordate

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    Harrison Richard G

    2011-01-01

    Full Text Available Abstract Background Reproductive character displacement (RCD is a common and taxonomically widespread pattern. In marine broadcast spawning organisms, behavioral and mechanical isolation are absent and prezygotic barriers between species often operate only during the fertilization process. Such barriers are usually a consequence of differences in the way in which sperm and egg proteins interact, so RCD can be manifest as faster evolution of these proteins between species in sympatry than allopatry. Rapid evolution of these proteins often appears to be a consequence of positive (directional selection. Here, we identify a set of candidate gamete recognition proteins (GRPs in the ascidian Ciona intestinalis and showed that these GRPs evolve more rapidly than control proteins (those not involved in gamete recognition. Choosing a subset of these gamete recognition proteins that show evidence of positive selection (CIPRO37.40.1, CIPRO60.5.1, CIPRO100.7.1, we then directly test the RCD hypothesis by comparing divergence (omega and polymorphism (McDonald-Kreitman, Tajima's D, Fu and Li's D and F, Fay and Wu's H statistics in sympatric and allopatric populations of two distinct forms of C. intestinalis (Types A and B between which there are strong post-zygotic barriers. Results Candidate gamete recognition proteins from two lineages of C. intestinalis (Type A and B are evolving more rapidly than control proteins, consistent with patterns seen in insects and mammals. However, ω (dN/dS is not significantly different between the sympatric and allopatric populations, and none of the polymorphism statistics show significant differences between sympatric and allopatric populations. Conclusions Enhanced prezygotic isolation in sympatry has become a well-known feature of gamete recognition proteins in marine broadcast spawners. But in most cases the evolutionary process or processes responsible for this pattern have not been identified. Although gamete

  19. Evolution of the interaction between Runx2 and VDR, two transcription factors involved in osteoblastogenesis

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    Barriga Elias H

    2010-03-01

    , using pull-down experiments between recombinant proteins, we show that the VDR homologue from teleosts, but not from ascidians, is able to directly interact with the mammalian Runx2 homologue. Conclusions We propose an evolutionary scenario for the assembly of the molecular machinery involving Runx2 and VDR in vertebrates. In the last common ancestor of actinopterygians and sacropterygians, the three Runx paralogues possessed the potential to physically and functionally interact with the VDR protein. Therefore, 1α,25-dihydroxyvitamin D3 might have been able to modulate the transcriptional activity of Runx1, Runx2 or Runx3 in the tissues expressing VDR. After the split from amphibians, in the lineage leading to amniotes, Runx2 and VDR became robustly co-expressed in developing skeletal elements, and their regulatory interaction was incorporated in the genetic program involved in the specification and differentiation of osteoblasts.

  20. Sperm precedence in a novel context: mating in a sessile marine invertebrate with dispersing sperm.

    Science.gov (United States)

    Bishop, J D; Pemberton, A J; Noble, L R

    2000-06-01

    The compound ascidian Diplosoma listerianum releases aquatic sperm which are dispersed passively to potential mates as individual gametes prior to storage of sperm, internal fertilization and brooding of embryos. The storage of exogenous sperm enables D. listerianum to produce a lengthy series of progeny following a brief period of mating. Molecular paternity analysis following sequential mating of colonies in laboratory culture revealed a consistent pattern with a clear initial bias in paternity towards the first of two acting males. The sites of sperm storage and fertilization and the morphology of the ovary in D. listerianum suggest that this bias reflects first-in-first-out use of individual stored gametes. The proportion of second-male paternity subsequently increased with time within the progeny arrays. This may have reflected the ageing or passive loss of first-male sperm. It is also possible that the modular nature of the organism contributed to this temporal trend: any recently budded colony modules maturing in the interval between matings would have been available exclusively to second-male sperm as virgin zooids. Two sets of mating trials were run. In the first, the collection of progeny suffered an interruption of 13 days and each male gained a larger proportion of recorded paternity within the progeny analysed when mating first rather than when mating second. In one mating combination, the first male obtained almost 100% of recorded paternity. In the second set of trials, with different clonal combinations, the complete sequence of progeny was collected and the estimated overall proportion of second-male paternity (P2) was consistently > 0.5. Taken as a whole, the results suggest that the overall P2-value can vary widely within the population studied. Proposed mechanisms of mating-order effects in species with copulatory mating include several which can have no counterpart in indirect aquatic mating since they involve the active removal, sealing off

  1. Proximate composition of marine invertebrates from tropical coastal waters, with emphasis on the relationship between nitrogen and protein contents

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    Graciela S Diniz

    2014-05-01

    Full Text Available The chemical profiles of Desmapsamma anchorata, Hymeniacidon heliophila (Porifera, Bunodosoma caissarum, Renilla muelleri (Cnidaria, Aplysia brasiliana, Eledone massyae, Isognomon bicolor (Mollusca, Echinaster brasiliensis, Echinometra lucunter, Holothuria grisea, Lytechinus variegatus (Echinodermata, and Phallusia nigra (Chordata were determined. Hydrosoluble protein was the most abundant class of substances for all species, except for the ascidian Phallusia nigra, in which the carbohydrate content was higher. The percentages of hydrosoluble protein (dry weight, dw varied widely among the invertebrates, ranging from 5.88% (R. muelleri to 47.6% (Eledone massyae of the dw .The carbohydrate content fluctuated from 1.3% (R. muelleri to 18.4% (Aplysia brasiliana of the dw. For most of the species, lipid was the second most abundant class of substances, varying from 2.8% (R. muelleri to 25.3% (Echinaster brasiliensis of the dw. Wide variations were also found for the invertebrates nitrogen content, with the lowest value recorded in the cnidarian R. muelleri (2.02% of the dw and the highest in the molluscan E. massyae (12.7% of the dw. The phosphorus content of the dw varyed from 0.24% (R. muelleri to 1.16% (E. massyae. The amino acid composition varied largely among the species, but for most of the species glycine, arginine, glutamic acid, and aspartic acid were the most abundant amino acids, with histidine and tyrosine among the less abundant amino acids. The actual content of total protein in the samples was calculated by the sum of amino acid residues, establishing dw values that fluctuated from 11.1% (R. muelleri to 66.7% (E. massyae. The proteinaceous nitrogen content was high in all species, with an average value of 97.3% of the total nitrogen. From data of total amino acid residues and total nitrogen, specific nitrogen-to-protein conversion factors were calculated for each species. The nitrogen-to-protein conversion factors ranged from 5.10 to

  2. Phylogeny of the Aplousobranchia (Tunicata: Ascidiacea Filogenia de Aplousobranchia (Tunicata: Ascidiacea

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    Tatiane R. Moreno

    2008-06-01

    Full Text Available The phylogenetic relationships of genera and families of Aplousobranchia Lahille (Tunicata, Ascidiacea is reconstructed based on morphological characters - the first comprehensive morphology-based phylogenetic analysis for the Aplousobranchia. Monophyly of Aplousobranchia and its families were tested with samples of 14 families. The final character matrix comprised 47 characters and 41 genera as terminal taxa. Nine equally most parsimonious trees (length 161, CI = 0.5031, RI = 0.7922 were found. Characters describing replication, colony system formation, and branchial walls were the more important in phylogenetic reconstruction. These characters were more useful than others more traditionally used in ascidian taxonomy, such as: body division, position of the heart, gonads and epicardium. Characters not frequently used in phylogenetic analysis, such as body wall muscles, muscles associated with transversal blood vessels and arrangement of the larval papillae, also have phylogenetic information. Results supported monophyly of the Aplousobranchia sensu Lahille, 1887 including only Polycitoridae, Polyclinidae, and Didemnidae. On the other hand, Aplousobranchia including also Cionidae and Diazonidae is not monophyletic since Perophora and Ecteinascidia were included as ingroups in the cladogram, Ciona (now closer to Ascidia was no longer included in Aplousobranchia and the position of Rhopalaea and Diazona is not resolved. We propose a revised classification based on this phylogenetic analysis, in which Aplousobranchia, with three new families and an indeterminate taxon, now has 15 families.O relacionamento filogenéticos de gêneros e famílias de de Aplousobranchia Lahille (Tunicata, Ascidiacea foi reconstruída com base em caracteres morfológicos - esta constitui a primeira análise filogenética morfológica abrangente para Aplousobranchia. A monofilia de Aplousobranchia e suas famílias foi testada com espécies de 14 famílias. A matriz final