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Academic literature on the topic 'Ascidian'

Author: Grafiati

Published: 4 June 2021

Last updated: 6 July 2024

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Journal articles on the topic "Ascidian"

Malintoi, Adrianus, Inneke F. M. Rumengan, Kakaskasen A. Roeroe, Veibe Warouw, Ari B. Rondonuwu, and Medy Ompi. "KOMUNITAS ASCIDIA DI PESISIR MALALAYANG DUA, TELUK MANADO, SULAWESI UTARA." JURNAL PESISIR DAN LAUT TROPIS 8, no. 1 (January 15, 2020): 39. http://dx.doi.org/10.35800/jplt.8.1.2020.27403.

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Field survey on ascidian community was conducted along the coastal area of Malalayang Dua in order to find out species of ascidia, species abundance, and ascidian substrates. A survey method and quadrant transects were applied. Pictures were taken, while species and their substrates were sampled. Species identification was based on morphological characteristics, while substrate type identification was based on ascidian species attachment. The results shows that 21 ascidian species were found in the the coastal of Malalayang Dua. Didemnum molle was the highest abundant species in the area, followed by Polycarpa aurata, Polycarpa sp.4. and Polycarpa sp.2.. Dead coral algaes (DCA) were found to be the most preferred substrates by ascidians in the area. Keywords : ascidia, species, substrate, distribution, and abundance Survei lapangan terhadap komunitas ascidia dilakukan di pesisir Malalayang Dua untuk mendapatkan data jenis, kelimpahan, dan substrat ascidia. Metode yang digunakan yaitu metode survei jelajah dan transek kuadran. Identifikasi jenis ascidia dilakukan berdasarkan karakteristik morfologi. Hasil penelitian ditemukan ada 21 jenis ascidia. Substrat jenis death coral algae (DCA) merupakan substrat yang paling banyak ditempati ascidia. Kelimpahan ascidia tertinggi adalah Didemnum molle di pesisir Malalayang Dua, diikuti oleh Polycarpa aurata, Polycarpa sp.4. dan Polycarpa sp.2. Death coral alga (DCA) ditemukan sebagai substrat yang paling disukai oleh ascidia di daerah itu. Kata Kunci : ascidia, spesies, substrat, distribusi, dan kelimpahan

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KNEER, DOMINIK, FRANCOISE MONNIOT, THOMAS STACH, and MARJOLIJN J. A. CHRISTIANEN. "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." Zootaxa 3616, no. 5 (February 22, 2013): 485–94. http://dx.doi.org/10.11646/zootaxa.3616.5.5.

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A new tunicate, Ascidia subterranea sp. nov., was found in burrows of the axiid crustacean Axiopsis serratifrons on De-rawan 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.

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Leleran, Andreas J. P. L., Silvester B. Pratasik, Meiske S. Salaki, Lawrence J. L. Lumingas, Alex D. Kambey, and Suzanne L. Undap. "Distribution and Diversity of Ascidian in Manado Bay, North Sulawesi." Jurnal Ilmiah PLATAX 10, no. 1 (April 14, 2022): 124. http://dx.doi.org/10.35800/jip.v10i1.38842.

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The purpose of this study was to determine the distribution and the diversity of ascidians in Manado Bay including species composition, density, diversity, and dominance. This study used the quadrat transect method. This study found differences in the number of ascidian species with water depth, 11 species of 5 families at 15 M depth, and 8 species of 3 families at 7 M depth. The diversity index ranged from 0.868 to 1.844 at 15 M depth and 0.965 to 1.864 at 7 M depth, the evenness index was 0.533 – 0.839 at 15 M depth and 0.600 – 0.897 at 7 M depth, the dominance index was 0.254 – 0.745 at 15 M depth and 0.254 – 0.708 at 7 M depth. Ascidian in Manado Bay had two distribution patterns, a uniform distribution pattern and a clustered distribution pattern. Environmental parameters had a water temperature of 27 oC – 31 oC, the salinity of 30 0/00 – 32 0/00, the brightness of 12 m – 14 m, and pH of 8 – 10.*Keywords: Ascidian; diversity; ecological index; distribution patternAbstrakTujuan dari penelitian ini adalah untuk mengetahui distribusi dan keanekaragaman jenis ascidia di perairan Teluk Manado meliputi: komposisi jenis, kepadatan individu, keanekaragaman, dan dominansi. Serta mengetahui pola distribusi ascidia. Penelitian ini menggunakan metode transek kuadran. Pada penelitian ini ditemukan perbedaan jumlah spesies ascidia menurut kedalaman, 11 spesies dari 5 family pada 15 M dan 8 spesies dari 3 famili pada kedalaman 7 m. Nilai indeks keanekaragaman ascidia di kedalaman 15 m = 0.868 – 1.844 dan 7 m = 0.965 - 1.864, indeks keseragaman 15 m = 0.533 – 0.839 dan 7 m = 0.600 – 0.897, indeks Dominasi15 m = 0.254 – 0.745 dan 7 m = 0.254 – 0.708. Ascdia di perairan Teluk Manado memiliki dua pola distribusi yaitu pola distribusi seragam dan pola distribusi mengelopok. Parameter lingkungan memiliki suhu air 27 oC – 31 oC, salinitas 30 0/00 – 32 0/00, kecerahan 12 m – 14 m, dan pH 8 – 10.*Kata kunci : Ascidia; keanekaragaman; indeks ekologi; pola distribusi

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Musak, Putra, Christian Palit, Mutiara Ratih, and Deiske A. Sumilat. "KOMPOSISI JENIS DAN KEPADATAN ASCIDIA Rhopalaea sp. DI PESISIR PANTAI KINAMANG, MALALAYANG DUA, TELUK MANADO." JURNAL PESISIR DAN LAUT TROPIS 10, no. 3 (October 2, 2022): 240–45. http://dx.doi.org/10.35800/jplt.10.3.2022.55008.

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Ascidian is one of the marine biotas with considerable potential in Indonesian waters but has not received serious attention. Therefore, a little research on this species is good to do with the aim of knowing the species composition and density of Rhopalaea sp. in Manado Bay waters with different depths. The purpose of this study was to analyze the Ascidian index to determine the species composition and density of Ascidian Rhopalaea sp. at different depths in Manado Bay waters, in this case the Kinamang coastal waters, Malalayang Dua. This research was carried out for 5 (five) months starting from April to August 2022. The tools and materials used in this study were: Global Positioning System (GPS), SCUBA set, roll meter, waterproof paper, writing utensils, camera, identification books, Horiba, laptop, Microsoft excel software and Ascidian. Data analysis was conducted to determine the composition and density of Ascidia Rhopalaea sp. The results obtained are Ascidia Rhopalaea sp. found there are 2 types, namely Rhopalaea and Rhopalaea crassa. After analyzing the data, Ascidian species R. crassa had higher composition and density values than Rhopalaea species. Keywords: Ascidian, Species Composition, Density, Manado Bay ABSTRAK Ascidia merupakan salah satu biota laut dengan potensi yang cukup besar di Perairan Indonesia akan tetapi belum mendapatkan perhatian yang serius. Oleh karena masih sedikit penelitian mengenai jenis ini sehingga penelitian ini baik untuk dilakukan dengan tujuan untuk mengetahui komposisi jenis dan kepadatan jenis Rhopalaea di Perairan Teluk Manado dengan kedalaman berbeda. Tujuan penelitian ini yaitu menganalisis indeks ascidia untuk mengetahui komposisi jenis dan kepadatan Ascidia Rhopalaea sp. pada kedalaman yang berbeda di Perairan Teluk Manado dalam hal ini perairan pesisir Kinamang, Malalayang Dua. Penelitian ini dilaksanakan selama 5 (lima) bulan dimulai pada bulan April sampai dengan Agustus tahun 2022. Alat dan bahan yang digunakan dalam penelitian ini yaitu : Global positioning system (GPS), Set SCUBA, roll meter, kertas anti air, alat tulis menulis, kamera, buku identifikasi, Horiba, laptop, software microsoft excel dan ascidia. Analisis data dilakukan untuk mengetahui komposisi jenis dan kepadatan Ascidia Rhopalaea sp. Hasil yang didapat yaitu Ascidia Rhopalaea sp. yang ditemukan berjumlah 2 jenis yaitu Rhopalaea dan Rhopalaea crassa. Setelah dilakukan Analisa data, Ascidia jenis R. crassa memiliki nilai komposisi jenis dan kepadatan yang lebih tinggi dari jenis Rhopalaea. Kata Kunci: Ascidia, Komposisi Jenis, kepadatan, Teluk Manado

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Macpal, Yuliana, Veibe Warouw, Deiske A. Sumilat, James J. H. Paulus, Natalie D. C. Rumampuk, and Reni L. Kreckhoff. "AKTIVITAS ANTIBAKTERI DAN ANTI-UV BEBERAPA ASCIDIAN DARI PERAIRAN PANGALISANG BUNAKEN." JURNAL PESISIR DAN LAUT TROPIS 7, no. 3 (July 23, 2019): 271. http://dx.doi.org/10.35800/jplt.7.3.2019.26019.

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Ascidians are sesile marine invertebrates that have bioactive compounds such as antibacterial and anti-UV. The purpose of this study is to determine the antibacterial activity against Escherichia coli and Staphylococcus aureus bacteria and to test the anti-UV activity of the ascidian water fraction. Antibacterial activity test was carried out using the diffusion method (disc diffusion Kirby & Bauer) and the water fraction of ascidian that showing antibacterial activity tested in a UV spectrophotometer to see the anti-UV activity. Results of the study were obtained 4 types of ascidians extracted from partitioned into water fraction, n-hexane fraction, methanol fraction. All three fractions were tested for antibacterial activity and the result showed that there were antibacterial activities of ascidian extract Clavelina sp. against both test bacteria with inhibition of S. aureus and E. coli with strong categories. Ascidian Phlebobranch sp. showed the presence of antibacterial activity with inhibition of S. aureus and E. coli with very strong categories (16,6 mm). extract Eudistoma sp. showed the presence of antibacterial activity with inhibition S. aureus and E. coli in the medium category (9 mm). The water fraction found active in antibacterial testing is then tested using a UV spectrophotometer for anti UV testing, the result show that water fraction of the four ascidians can absorb UV-B (290-320nm) and UV-A ( 320-400nm).Keywords : Ascidian, Antibacterial, Partition, Anti- UV.

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Tatian, M., R. J. Sahade, M. E. Doucet, and G. B. Esnal. "Ascidians (Tunicata, Ascidiacea) of Potter Cove, South Shetland Islands, Antarctica." Antarctic Science 10, no. 2 (June 1998): 147–52. http://dx.doi.org/10.1017/s0954102098000194.

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Certain physical factors, substrate type and ice action appear to be important determinants for ascidian distribution. Three different substrate types were sampled at depths between 0–30 m by SCUBA diving: soft bottoms, hard bottoms and moraine deposits. The species found were Aplidium radiatum, Synoicum adareanum, Distaplia cylindrica, Sycozoa gaimardi, Sycozoa sigillinoides, Tylobranchion speciosum, Corella eumyota, Ascidia challengeri, Cnemidocarpa verrucosa, Styela wandeli, Dicarpa insinuosa, Pyura bouvetensis, Pyura discoveryi, Pyura obesa, Pyura setosa, Molgula enodis and Molgula pedunculata. Highest diversity and patchy distribution was found in less stringent environments, where epibiosis is a commmon phenomenon on stolidobranch ascidians. Differences in stalk development were found in the most abundant species Molgula pedunculata and Cnemidocarpa verrucosa. Ice action may be the main factor that determines the absence of ascidians above 15 m in all the stations sampled.

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Hasegawa, Naohiro, Natsumi Hookabe, Yoshihiro Fujiwara, Naoto Jimi, and Hiroshi Kajihara. "Supplemental re-description of a deep-sea ascidian, Fimbrora calsubia (Ascidiacea, Enterogona), with an inference of its phylogenetic position." Zoosystematics and Evolution 100, no. 1 (January 26, 2024): 129–40. http://dx.doi.org/10.3897/zse.100.113132.

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Fimbrora Monniot & Monniot, 1991, a macrophagous ascidian genus within the family Ascidiidae Adams & Adams, 1858, is currently monotypic, represented by F. calsubia Monniot & Monniot, 1991, a species previously recorded from the bottom of the South Pacific at depths of 1000–1860 m. The taxonomic status of Fimbrora has remained ambiguous because characteristics in its branchial papillae and neural-gland opening are incompletely known in previous studies, while these traits are essential for distinguishing other ascidiid genera. So far, no nucleotide sequence representing F. calsubia is available. In this study, we collected a single specimen of F. calsubia at a depth of 2027 m, about 400 km off the Pacific coast of Honshu, Japan. This is the deepest record, as well as the first report from the North Pacific, for the species. Our examination indicates that Fimbrora is morphologically similar to another ascidiid genus, Psammascidia Monniot, 1962, by having only secondary branchial papillae in the pharynx. Our phylogenetic analysis, based on the 18S ribosomal RNA and cytochrome c oxidase subunit I genes, along with those of 27 ascidian species available in public databases, showed that F. calsubia was more closely related to Ascidia zara Oka, 1935, Phallusia fumigata (Grube, 1864) and Phallusia mammilata (Cuvier, 1815) than to Ascidia ceratodes (Huntsman, 1912), Ascidiella aspersa (Müller, 1776) and Ascidiella scabra (Müller, 1776). Our results also indicated that acquisitions of macrophagous feeding by deep-sea members happened independently at least three times in the evolutionary history of the entire Ascidiacea.

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Koike, I., M. Yamamuro, and PC Pollard. "Carbon and nitrogen budgets of two Ascidians and their symbiont, Prochloron, in a tropical seagrass meadow." Marine and Freshwater Research 44, no. 1 (1993): 173. http://dx.doi.org/10.1071/mf9930173.

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Two species of ascidian, Didemnum molle Herdman and Lissoclinum voeltzkowi Michaelsen, were collected from a Fijian seagrass meadow. The primary production of their symbiont (Prochloron), the inorganic nitrogen metabolism and the filtration rate were measured to assess the nutritional coupling between the symbiont and the host animal. The loss of organic carbon due to the respiration of D. molle (1.1 �g at. C (mg dry wt)-1 day-1) was greater than that supplied through photosynthesis of the Prochloron (0.69 �g at. C (mg dry wt)-1 day,-1). The carbon supplied through filter-feeding appeared to supplement the ascidian's carbon budget. In contrast, organic carbon from the Prochloron of L. voeltzkowi appeared to meet the colony's respiration needs. The nitrogen budgets of both ascidian colonies were estimated from their respiration rates, the nitrogen requirement of the Prochloron, and the uptake of inorganic nitrogen and particulate organic nitrogen uptake from the water column. The nitrogen incorporated from the surrounding environment could contribute to the net nitrogen gain of the colony. However, our estimate of the nitrogen needed by the Prochloron was much greater than that which could be supplied externally. The amount of nitrogen released by the ascidians was also greater than that which could be supplied externally. This suggests that nitrogen is efficiently recycled within the symbiotic Prochloron-ascidian relationship.

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Hirose, Euichi, Kaori Ohtsuka, Masaharu Ishikura, and Tadashi Maruyama. "Ultraviolet absorption in ascidian tunic and ascidian-Prochloron symbiosis." Journal of the Marine Biological Association of the United Kingdom 84, no. 4 (August 2004): 789–94. http://dx.doi.org/10.1017/s0025315404009956h.

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To characterize the ultraviolet (UV) light-absorbing function of the ascidian tunic, the light absorption spectrum was compared in 22 ascidian species collected from tropical and temperate waters. Non-photosymbiotic ascidians (17 species) had transparent tunics transmitting both visible and UV light, or pigmented or opaque tunics equally absorb both UV and visible light. However, a prominent absorption peak around 320 nm was exclusively found in the colonial ascidians hosting the algal symbiont Prochloron sp., and this absorption peak corresponded to absorption of UV-A (320–400 nm) and UV-B (280–320 nm). The UV-absorbing substances were extracted with methanol. They were mycosporine-like amino acids (MAAs): mycosporine-glycine, palythine, shinorine, and porphyra-334. The MAAs are thought to be synthesized by the shikimic acid pathway that does not occur in animals. Since the isolated Prochloron cells contain MAAs, the symbionts are the most possible candidates as the source of the MAAs in the tunic. In Diplosoma virens, the composition of MAAs was different between isolated Prochloron cells and colony residue from which Prochloron cells were extracted.

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Cone, Angela C., and Robert W. Zeller. "Using ascidian embryos to study the evolution of developmental gene regulatory networks." Canadian Journal of Zoology 83, no. 1 (January 1, 2005): 75–89. http://dx.doi.org/10.1139/z04-165.

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Ascidians are ideally positioned taxonomically at the base of the chordate tree to provide a point of comparison for developmental regulatory mechanisms that operate among protostomes, non-chordate deuterostomes, invertebrate chordates, and vertebrates. In this review, we propose a model for the gene regulatory network that gives rise to the ascidian notochord. The purpose of this model is not to clarify all of the interactions between molecules of this network, but to provide a working schematic of the regulatory architecture that leads to the specification of endoderm and the patterning of mesoderm in ascidian embryos. We describe a series of approaches, both computational and biological, that are currently being used, or are in development, for the study of ascidian embryo gene regulatory networks. It is our belief that the tools now available to ascidian biologists, in combination with a streamlined mode of development and small genome size, will allow for more rapid dissection of developmental gene regulatory networks than in more complex organisms such as vertebrates. It is our hope that the analysis of gene regulatory networks in ascidians can provide a basic template which will allow developmental biologists to superimpose the modifications and novelties that have arisen during deuterostome evolution.

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Dissertations / Theses on the topic "Ascidian"

Guignard, Léo. "Analyse quantitative de la morphogenèse animale : de l'imagerie laser haut-débit à l'embryon virtuel chez les ascidies." Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS048/document.

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Les embryons d'ascidies se développent avec un lignage cellulaire stéréotypé et évolutionairement conservé pour produire en quelques heures ou jours un têtard comportant un petit nombre de cellules. De ce fait, ils fournissent un cadre intéressant pour décrire avec une résolution cellulaire le programme de développement d’un organisme complet. Pendant mon doctorat, j’ai développé une approche quantitative pour décrire l’évolution morphologique embryonnaire pendant le développement de Phallusia mammillata. J’ai ensuite utilisé cette approche pour systématiquement caractériser en détail les logiques des événements de spécifications de destin cellulaire.Pour caractériser quantitativement les comportements cellulaires pendant l’embryogenèse, nous avons utilisé de la microscopie à feuille de lumière multi-angles pour imager des embryons entiers à haute résolution spatio-temporelle. Les membranes plasmiques étaient marquées pour permettre l’identification des cellules. Pour extraire les informations biologiques de ce jeu de donnés, j’ai développé une nouvelle méthode pour segmenter les cellules en 4D, ASTEC. Une fois appliquée aux embryons de Phallusia mammillata imagés pendant 6 heures entre le stade 64 cellules et le début des stades bourgeon caudal, cette méthode a permis de récupérer la forme et de suivre 1030 cellules pendant 640 divisions. L’embryon digital 4D résultant peut être formalisé par un graphe dynamique, dans lequel les cellules sont représentées par des sommets reliés par des arrêtes représentant au sein d’un point de temps leur voisinage spatial, et entre différents points de temps leur lignage cellulaire.Basé sur cette représentation digitale et quantitative, nous avons systématiquement identifié les événements de spécification cellulaire jusqu’au dernier stade de la gastrulation. Des simulations informatiques ont révélé que des règles remarquablement simples intégrant les aires de contacts cellulaires et les expressions spatio-temporelles booléennes de signaux moléculaires extracellulaires sont suffisantes pour expliquer les inductions cellulaires au cours du développement précoce. Ce travail suggère que pour les embryons établissant des contacts stéréotypés et précis entre cellules voisines, les contraintes génomiques sont relâchées, ce qui permet une évolution plus rapide du génome
Ascidian embryos develop with stereotyped and evolutionarily conserved invariant cell lineages to produce in a few hours or days tadpole larvae with a small number of cells. They thus provide an attractive framework to describe with cellular resolution the developmental program of a whole organism. During my PhD, I developed a quantitative approach to describe the evolution of embryonic morphologies during the development of the ascidian Phallusia mammillata. I then used this approach to systematically characterize in detail the logic of cell fate induction events. To quantitatively characterize cell behaviors during embryogenesis, we used multi-angle light-sheet microscopy to image with high spatio-temporal resolution entire live embryos with fluorescently labeled plasma membranes. To extract biological information from this imaging dataset, I then developed a conceptually novel automated method for 4D cell segmentation, ASTEC. Applied to a Phallusia mammillata embryo imaged for 6 hours between the 64-cell and the initial tailbud stages, this method allows the accurate tracking and shape analysis of 1030 cells across 640 cell divisions. The resulting 4D digital embryo can be formalized as a dynamic graph, in which cells are represented by nodes, linked within a time point by edges that represent their spatial neighborhood, and between time points by temporal edges describing cell lineages.Based on this quantitative digital representation, we systematically identified cell fate specification events up to the late gastrula stage. Computational simulations revealed that remarkably simple rules integrating measured cell-cell contact areas with boolean spatio-temporal expression data for extracellular signalling molecules are sufficient to explain most early cell inductions. This work suggests that in embryos establishing precise stereotyped contacts between neighboring cells, the genomic constraints for precise gene expression levels are relaxed, thereby allowing rapid genome evolution

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Evans, Rowan. "Reproduction of the unitary, larviparous ascidian Dendroda grossularia." Thesis, University of Liverpool, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.260360.

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Madgwick, Alicia. "Evolution des programmes transcriptionnels développementaux des ascidies Ciona robusta et Phallusia mammillata." Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTT137/document.

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Comment la morphogenèse embryonnaire peut-elle être conservée malgré une divergence importante des séquences codantes et non-codantes ? Pour répondre à cette question, nous avons travaillé sur le développement précoce d’ascidies divergentes, Phallusia mammillata et Ciona intestinalis. Ces espèces partagent une morphogénèse pratiquement identique et des lignages cellulaires stéréotypés. Or, leurs génomes sont tellement divergents que leurs séquences ne peuvent pas être alignées.Nous avons choisi d’étudier les cellules précurseuses de l’endoderme au cours de deux processus développementaux conservés : spécification du destin et la gastrulation. Nous avons comparé par hybridation in situ l’expression transcriptionelle des gènes régulateurs orthologues dans Phallusia et Ciona. Nous avons trouvé que l’expression dans l’endoderme de 8 gènes régulateurs impliqués dans ces processus développementaux est qualitativement conservée entre les deux espèces.Pour étudier comment ces gènes ont conservé leur régulation malgré une divergence non-codante importante, nous avons collaboré avec l’équipe Gomez-Skarmeta pour cartographier, par ATAC-seq, la chromatine ouverte dans les deux espèces pour identifier les régions régulatrices actives à l’échelle du génome. 35 sur les 39 séquences ouvertes avoisinant les gènes de l’endoderme ont été trouvé active avant le stade larval, par éléctroporation. La plupart des séquences testées ont conservé leur activité dans les deux espèces malgré la divergence de séquence. Nous avons alors identifié des sites de fixations pour facteurs de transcription potentiels se trouvant dans les enhancers pour l’endoderme pour identifier les régulateurs dans Phallusia et Ciona.Nos résultats suggèrent des changements assez importants de l’ordre des sites de fixations sans pour autant avoir de changement dans l’architecture dans les réseaux de gènes régulateurs ; ceci explique la conservation qualitative de l’expression des gènes entre ces ascidies divergentes. En outre, nous avons trouvé que les shadow enhancers sont plus répandus qu’anticipé
How can embryonic morphogenesis be evolutionarily conserved in spite of extensive divergence in coding and non-coding genome sequences? To address this question, we worked on the early development of two very divergent ascidians, Phallusia mammillata and Ciona intestinalis. These species share an almost identical early morphogenesis and stereotyped cell lineages. Remarkably, however, their genomes are divergent to the extent that their non-coding sequences cannot be aligned and gene order has not been conserved.We focus our attention on the behaviour of endoderm precursors throughout two important evolutionarily conserved developmental processes: initial fate specification and early gastrulation. We first compared by in situ hybridisation the transcriptional expression of orthologous regulatory genes in Phallusia and in Ciona. We found that the endodermal expression of 8 regulatory genes known to be involved in these developmental processes is qualitatively conserved between the two species.To study how these genes conserved their regulation in spite of extensive non-coding sequence divergence, we collaborated with the Gomez-Skarmeta lab to map, by ATAC-seq, open chromatin regions in both species to identify active regulatory regions genomewide. Three quarters of the 39 open chromatin regions for endodermal genes behaved as active regulatory sequences by the larval stage, when tested by electroporation in embryos. Many of the tested sequences had conserved cis-regulatory activity in both species in spite of sequence divergence. We have identifed putative transcription factor binding sites in endodermal enhancers in both species to identify conserved upstream regulators shared between Phallusia and Ciona.Taken together our results suggest that extensive transcription factor binding site turn over, without radical change in GRNs architecture, may explain the qualitative conservation of gene expression patterns between highly divergent ascidian genomes. Furthermore, we found that shadow enhancers are much more prevalent than initially anticipated.Taken together our results suggest that extensive transcription factor binding site turn over, without radical change in GRNs architecture, may explain the qualitative conservation of gene expression patterns between highly divergent ascidian genomes. Furthermore, we found that shadow enhancers are much more prevalent than initially anticipated

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西川, 輝昭, Teruaki Nishikawa, D. D. Bishop John, and Dorothea Sommerfeldt A. "Occurrence of the alien ascidian Perophora japonica at Plymouth." Cambridge University Press, 2000. http://hdl.handle.net/2237/10552.

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Johnson, Sheri L. "Mating System Dynamics in a Free-Spawning Colonial Ascidian." Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/JohnsonSL2007.pdf.

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Bevis, Peter John. "Studies on gastrointestinal peptides in the ascidian Styela clava." Thesis, Royal Holloway, University of London, 1985. http://repository.royalholloway.ac.uk/items/2ce39101-08bf-48be-be30-1042d191f253/1/.

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Cells analogous to vertebrate endocrine cells have been described in the gut epithelium of the ascidian Styela clava. As well as some histochemical similarities, ultrastructural correlations have been demonstrated, particularly the presence of electron dense granules, clustered around and mainly below the nucleus, thinning out towards the apex. Like the endocrine cells of the vertebrate gut, the cells are often pyramidal, with a narrow apex which is occasionally observed to extend to the lumen of the gut. In addition, strong secretin immunofluorescence was observed in the endocrine-like (E-L) cells of the mucous cap of the gastric ridges. Because of these observations, acid extracts of Styela gut were assayed for secretin in the rat and in the turkey. The Styela extracts as prepared were inactive but it is possible that this reflected faults in the extraction technique. Development of a perfused Styela gut preparation, however, produced evidence to support the hypothesis that a CCK-like peptide is released into the circulation, presumably from the E-L cap cells, although CCK-like immunoreactivity is not demonstrable in these cells. The observation that in addition to CCK, bombesin and physalaemin also induce enzyme release suggests that the pre-pancreatic zymogen cells contain a rich complement of receptors, corresponding to all the classes of PI stimulating receptors which have been found on vertebrate acinar cells. There is therefore the implication that these hormones or analogues may be present in Styela. As secretin was found not to act as a secretagogue in this system, the significance of its production is unclear. By analogy with vertebrate systems it may exert some control over the secretion of mucus by the cap cells.

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Peddie, Clare M. "Lymphocyte-like functions in the solitary ascidian Ciona intestinalis." Thesis, University of St Andrews, 1995. http://hdl.handle.net/10023/13994.

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The blood cells of the solitary ascidian, Ciona intestinalis, were examined for lymphocyte-like functions with a view to clarifying the phylogenetic origin of lymphocytes in invertebrates. It was found that cells, present in the circulating blood, mediate the haemolysis of sheep red blood cells, and that a different cell type mediates cytotoxic activity against a range of mammalian tumour cell lines in vitro. The blood cells, cytotoxic to mammalian cell lines, were enriched by continuous density gradient centrifugation, and their activity was ameliorated by heat-treatment. Parameters of cytotoxic activity against the target cell line, WEHI, a mouse myelomonocytic leukemic cell (strain 3B), were ascertained by fluorochromasia and the phenomenon was found to be rapid, temperature dependent and sensitive to osmotic conditions. Cytotoxicity was also found to be dependent upon the presence of magnesium and calcium ions, effector to target cell binding, and active metabolic, cytoskeletal and secretory processes in the effector cells. The cytotoxic cells were non-adherent to glass or nylon wool and transmission electron microscope studies of the target-binding cells showed that they were undifferentiated, with a high nucleus to cytoplasm ratio, containing a few large mitochondria, some profiles of rough endoplasmic reticulum and many free ribosomes. In addition, TEM studies revealed close inter-digitation of the effector and target cell membranes and evidence of secretory activity within the effector cell, in the area of target cell binding. The effector cell population was cultured in vitro and proliferation in response to concanavalin A, phytohaemagglutinin-B, lipopolysaccharide, or allogeneic leucocytes, measured by the uptake of tritiated thymidine, showed that these cells respond to both T and B cell mitogens and exhibit a mixed leucocyte reaction. In addition, the culture of pharyngeal explants and the measurement of cytotoxic activity by cells migrating from the explants indicates that the cytotoxic cells originate in a thymus-like haemopoietic tissue. Therefore, the undifferentiated blood cells of C. intestinalis, possess functional and morphological properties consistent with phylogenetic precursors of vertebrate lymphocytes.

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Khandelwal, Mudrika. "Structure and processing of fibrous cellulose : bacterial and ascidian material." Thesis, University of Cambridge, 2013. https://www.repository.cam.ac.uk/handle/1810/244716.

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Cleto, Cynthia. "Analysis of transcriptional elements of an ascidian troponin I gene." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33733.

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A long-range research interest of this laboratory is the evolution of the transcriptional control mechanisms of the vertebrate troponin I (TnI) gene family. It is likely that the vertebrate TnI gene family arose from a single TnI gene present in early chordate ancestors. Analysis of transcriptional control mechanisms of the TnI gene of a primitive chordate, such as the ascidian Ciona intestinalis, may therefore provide insight into the regulatory mechanisms of the vertebrate ancestral TnI gene. As an initial step in such a study, I localized transcriptional control regions within 1.5 kb of 5'-flanking DNA of the Ciona TnI gene. I prepared a series of deletion constructs in which Ciona TnI 5'-flanking DNA segments were fused to a nuclear-targeted beta-galactosidase reporter gene. Constructs were introduced into fertilized Ciona eggs by electroporation, and following development up to the mid tailbud stage (12 h), reporter gene expression was assessed by whole-mount beta-galactosidase histochemistry. (Abstract shortened by UMI.)

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Pemberton, A. J. "Aspects of mate choice in the colonial ascidian Diplosoma listerianum." Thesis, University of Aberdeen, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.593279.

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The hermaphrodite, colonial ascidian Diplosoma listerianum (Chordata: Urochordata) mates by releasing sperm that disperse to neighbours, where they fertilise eggs that have been retained internally rather than spawned. The species is able to utilise highly dilute sperm: comparison with published information on a sea urchin, which released both eggs and sperm for external fertilisation, showed that D. listerianum maintained comparable levels of fertilisation at sperm concentrations two or three orders of magnitude lower than the echinoderm. Laboratory clones of D. listerianum displayed surprisingly high levels of sexual incompatibility. Fecundities of numerous pairwise crosses varied widely and suggested a continuous scale of computability. Although correlations of computability between reciprocal crosses appeared positive, considerable noise was present in the data and some crosses showed strongly asymmetrical compatibility. Patterns of sperm precedence with a five-day mating internal showed clear initial bias towards the first of two acting males. The proportion of second-male paternity (P₂) subsequently increased with time. Estimated P₂ for entire progeny arrays was consistently greater than 0.5, but varied widely. When mating interval was reduced, mate order effects appeared to be moderated. In competition with an alternative sperm source, acting males fathered more progeny if previously mated to a particular female than if no mating history existed, an advantage probably derived from fertilisations by stored sperm. When virgin acting female colonies were given mixtures of sperm at widely divergent concentrations, offspring were shared between the two sperm sources in approximately the ratio of each mixture. However, there existed a small but statistically significant deviation from the fair raffle model, in that sperm at the lower concentration consistently achieved a greater than expected share of paternity. Environmentally-determined fixed female preferences could be responsible for this negative frequency dependence ('rare male effect').

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Books on the topic "Ascidian"

Daley, Bryon A. An integrated assessment of the continued spread and potential impacts of the colonial ascidian, didemnum sp. A, in U.S. waters. [Silver Spring, Md: U.S. Dept, of Commervce, National Oceanic and Atmospheric Administration, National Ocean Service, 2008.

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Sasakura, Yasunori, ed. Transgenic Ascidians. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-10-7545-2.

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Developmental biology of ascidians. Cambridge [England]: Cambridge University Press, 1994.

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Sawada, Hitoshi, Hideyoshi Yokosawa, and Charles C. Lambert, eds. The Biology of Ascidians. Tokyo: Springer Japan, 2001. http://dx.doi.org/10.1007/978-4-431-66982-1.

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Satoh, Noriyuki. Developmental Genomics of Ascidians. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118656129.

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Jaffar Ali, H. Abdul, and M. Tamilselvi. Ascidians in Coastal Water. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-29118-5.

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Monniot, Claude. Coral reef ascidians of New Caledonia. Paris: Éditions de l'ORSTOM, Institut français de recherche scientifique pour le développement en coopération, 1991.

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Monniot, Claude. Les Ascidies de Polynésie française. Paris: Editions du Muséum, 1987.

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Kühne, Stephan. Solitäre Ascidien in der Potter Cove (King George Island, Antarktis): Ihre ökologische Bedeutung und Populationsdynamik = Solitary Ascidians in the Potter Cove (King George Island, Antarctica) : their ecological role and population dynamics. Bremerhaven: Alfred-Wegener-Institut für Polar- und Meeresforschung, 1997.

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Groepler, Wolfgang. Die Seescheiden von Helgoland: Biologie und Bestimmung der Ascidien. Hohenwarsleben: Westarp Wissenschaften, 2012.

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Book chapters on the topic "Ascidian"

Twyman, R. M. "Ascidian Development." In BIOS Instant Notes in Developmental Biology, 197–200. London: Taylor & Francis, 2023. http://dx.doi.org/10.1201/9781003416371-37.

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Satou, Yutaka, and Kaoru S. Imai. "Ascidian Zic Genes." In Advances in Experimental Medicine and Biology, 87–106. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-10-7311-3_6.

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Parrinello, Nicolò, Matteo Cammarata, Mirella Vazzana, Vincenzo Arizza, Aiti Vizzini, and Edwin L. Cooper. "Immunological Activity of Ascidian Hemocytes." In The Biology of Ascidians, 395–401. Tokyo: Springer Japan, 2001. http://dx.doi.org/10.1007/978-4-431-66982-1_58.

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Satake, Honoo. "Ascidian Neuropeptides and Peptide Hormones." In Advances in Invertebrate (Neuro)Endocrinology, 409–36. Includes bibliographical references and indexes. | Contents: Volume 1. Phyla other than arthropoda.: Apple Academic Press, 2020. http://dx.doi.org/10.1201/9781003029854-11.

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Yasuo, Hitoyoshi, and Alex McDougall. "Practical Guide for Ascidian Microinjection: Phallusia mammillata." In Transgenic Ascidians, 15–24. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-10-7545-2_3.

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Nishikata, Takahito, Michiko R. Wada, and Kimio J. Tanaka. "RNA-binding Proteins In Ascidian Development." In The Biology of Ascidians, 178–85. Tokyo: Springer Japan, 2001. http://dx.doi.org/10.1007/978-4-431-66982-1_28.

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Nishino, Atsuo. "Morphology and Physiology of the Ascidian Nervous Systems and the Effectors." In Transgenic Ascidians, 179–96. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-10-7545-2_16.

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Jeffery, William R., Rebecca L. Beach, Frederick E. Harrington, Billie J. Swalla, and Mary E. White. "Patterns of Gene Expression During Ascidian Development." In Experimental Embryology in Aquatic Plants and Animals, 291–314. Boston, MA: Springer US, 1990. http://dx.doi.org/10.1007/978-1-4615-3830-1_17.

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Sawada, Hitoshi, Kazunori Yamamoto, Kei Otsuka, Takako Saito, Akira Yamaguchi, Masako Mino, Mari Akasaka, Yoshito Harada, and Lixy Yamada. "Allorecognition and Lysin Systems During Ascidian Fertilization." In Sexual Reproduction in Animals and Plants, 231–44. Tokyo: Springer Japan, 2014. http://dx.doi.org/10.1007/978-4-431-54589-7_20.

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Sasakura, Yasunori. "Germline Transformation in the Ascidian Ciona intestinalis." In Sexual Reproduction in Animals and Plants, 465–73. Tokyo: Springer Japan, 2014. http://dx.doi.org/10.1007/978-4-431-54589-7_38.

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Conference papers on the topic "Ascidian"

Michelin, Gael, Leo Guignard, Ulla-Maj Fiuza, Patrick Lemaire, Christophe Godine, and Gregoire Malandain. "Cell pairings for ascidian embryo registration." In 2015 IEEE 12th International Symposium on Biomedical Imaging (ISBI 2015). IEEE, 2015. http://dx.doi.org/10.1109/isbi.2015.7163872.

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Roshal, D. S., K. K. Fedorenko, K. Azzag, S. B. Roshal, and S. Bagdighyan. "ANALYSIS AND MODELING OF THE TOPOLOGY OF CANCEROUS, HEALTHY AND NON-PROLIFERATIVE EPITHELIUM." In X Международная конференция молодых ученых: биоинформатиков, биотехнологов, биофизиков, вирусологов и молекулярных биологов — 2023. Novosibirsk State University, 2023. http://dx.doi.org/10.25205/978-5-4437-1526-1-210.

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The topological features of epithelial monolayers with different rates of cell division are analyzed, using monolayers of HeLa, HCerEpiC, COS cells, ascidian epithelium. It is shown that the topological defectiveness of the monolayer increases with an increase in the rate of cell division. Modeling of the structure and growth processes of the epithelia was carried out.

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Sardet, C., C. Rouvière, B. Flannery, and J. Davoust. "Time lapse confocal microscopy of mitochondrial movements in ascidian embryos." In The living cell in four dimensions. AIP, 1991. http://dx.doi.org/10.1063/1.40578.

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Guignard, Léo. "Contact area–dependent cell communications and the morphological invariance of ascidian embryogenesis." In Virtual 12th Light Sheet Fluorescence Microscopy Conference 2020. Royal Microscopical Society, 2020. http://dx.doi.org/10.22443/rms.lsfm2020.10.

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Abdollahian, Golnaz, Michael Veeman, William Smith, and B. S. Manjunath. "A curvicylindrical coordinate system for the visualization and segmentation of the ascidian tail." In 2011 8th IEEE International Symposium on Biomedical Imaging (ISBI 2011). IEEE, 2011. http://dx.doi.org/10.1109/isbi.2011.5872383.

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Chen, Bin, Minglv Sun, Aili Jiang, and Changhai Wang. "Notice of Retraction: Antioxidant Activities of Crude and Fractionated Extracts from the Ascidian Styela clava." In 2011 5th International Conference on Bioinformatics and Biomedical Engineering. IEEE, 2011. http://dx.doi.org/10.1109/icbbe.2011.5780437.

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Wewengkang, Defny S., Henki Rotinsulu, Deiske A. Sumilat, Hiroyuki Yamazaki, Syu-Ichi Kanno, and Michio Namikoshi. "Evaluation on bioactivity of ascidian collected in North Sulawesi as seeds of marine-derived drugs." In THE 2ND INTERNATIONAL CONFERENCE ON NATURAL SCIENCES, MATHEMATICS, APPLICATIONS, RESEARCH, AND TECHNOLOGY (ICON-SMART 2021): Materials Science and Bioinformatics for Medical, Food, and Marine Industries. AIP Publishing, 2023. http://dx.doi.org/10.1063/5.0119405.

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Putra, M. Y., and F. Karim. "Antibacterial and antioxidant activity-guided isolation studies on Fusarium sp. associated with the ascidian Botryllus schlosseri." In THE 8TH INTERNATIONAL CONFERENCE OF THE INDONESIAN CHEMICAL SOCIETY (ICICS) 2019. AIP Publishing, 2020. http://dx.doi.org/10.1063/5.0001297.

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Sun, Minglv, Bin Chen, Aili Jiang, and Changhai Wang. "Notice of Retraction: Extraction and Antioxidant Activities of Oligosaccharides from Different Parts of the Ascidian Styela Clava." In 2011 5th International Conference on Bioinformatics and Biomedical Engineering. IEEE, 2011. http://dx.doi.org/10.1109/icbbe.2011.5780431.

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Ueki, Tatsuya, and Tri Kustono Adi. "Mechanism of vanadium accumulation and possible function of vanadium in underwater adhesion in ascidians." In INTERNATIONAL CONFERENCE ON BIOLOGY AND APPLIED SCIENCE (ICOBAS). AIP Publishing, 2019. http://dx.doi.org/10.1063/1.5115602.

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Reports on the topic "Ascidian"

Kincaid, Erin. Biofouling Management in the Pacific Northwest and Predation on Native versus Non-native Ascidians. Portland State University Library, January 2000. http://dx.doi.org/10.15760/etd.3067.

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