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Leandro Sastre - One of the best experts on this subject based on the ideXlab platform.
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Characterization of a functional serum response element in the Actin403 gene promoter from the crustacean Artemia franciscana
FEBS Journal, 2001Co-Authors: Marie-carmen Casero, Leandro SastreAbstract:The serum response factor (SRF) activates expression of several genes in response to growth factors present in serum. SRF also regulates the expression of tissue-specific genes, including those in vertebrate muscles. An SRF-binding site (CArG box) present in the Artemia franciscana Actin403 promoter was shown to be necessary for transcriptional activity in cultured cells from Drosophila melanogaster and mammals. This DNA region bound mammalian and Drosophila SRFs in vitro and mediated transcriptional activation of the Actin403 promoter in response to serum, phorbol esters and lysophosphatidic acid in transfected cultured mammalian cells. Mutations in the CArG box greatly reduced promoter activity and stimulation by extracellular compounds.
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A serum response factor homologue is expressed in ectodermal tissues during development of the crustacean Artemia franciscana.
Mechanisms of Development, 2000Co-Authors: Marie-carmen Casero, Leandro SastreAbstract:Abstract Complementary DNA clones have been isolated from the crustacean Artemia franciscana coding for a serum response factor (SRF)-homologue that is more than 96% identical to human and Drosophila melanogaster SRFs in their MADS boxes. The SRF homologue is expressed in ectodermal tissues, as determined by in situ hybridization experiments. A SRF-binding site has been identified in the promoter region of the Actin403 gene that is also expressed in ectodermal tissues, in accordance with its transcriptional regulation by the SRF homologue. The mRNA coding for A. franciscana SRF is present at similar levels in cryptobiotic encysted embryos and in developing nauplii. However, there is a significant increase in CArG-binding activity at the later developmental stage, indicating a postranscriptional regulation of SRF during A. franciscana embryonic development.
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Tissue-specific expression of two Artemia franciscana sarco/endoplasmic reticulum Ca-ATPase isoforms.
Journal of Histochemistry and Cytochemistry, 1996Co-Authors: Ricardo Escalante, Leandro SastreAbstract:The sarco/endoplasmic reticulum Ca-ATPase (SERCA) gene from Artemia franciscana is transcribed into two mRNAs that code for two different enzyme isoforms. We investigated the tissue-specific expression of each mRNA by in situ hybridization of larval tissue sections. One of the isoforms is expressed in the muscle fibers of the appendages. The other isoform is generally expressed throughout all tissues of the larvae. The tissue distribution of these two isoforms is very similar to the one described for the two homologous isoforms generated from the vertebrate SERCA 2 gene, and shows the evolutionarily conserved nature of their tissue-specific expression.
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Identification of an Artemia franciscana retropseudogene containing part of the last exons of the sarco/endoplasmic reticulum Ca-ATPase-encoding SERCA gene
Gene, 1994Co-Authors: Ricardo Escalante, Leandro SastreAbstract:Abstract A genomic clone has been isolated which contains sequences highly homologous to part of exon 14 and exons 15, 16 and 17 of the Artemia franciscana sarco-endoplasmic reticulum Ca-ATPase(SERCA)-encoding gene, but none of the introns. The homologous region extends to the 3′ end of the mRNA, although the poly(A) tail is not present. The structure of this clone suggests that it represents a 5′-end-truncated retropseudogene (rΨ).
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Gene expression after resumption of development of Artemia franciscana cryptobiotic embryos
Biochemistry and Cell Biology, 1994Co-Authors: Ricardo Escalante, Alberto García-sáez, Maria-asunción Ortega, Leandro SastreAbstract:The steady-state levels of six different mRNAs have been studied during Artemia franciscana development. Some of these mRNAs are present in the cryptobiotic cyst, like those coding for cytoplasmic actins, sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPase, and the Na+, K(+)-ATPase alpha-subunit isoform coded by the clone pArATNa136. The expression of these mRNAs is markedly induced during cyst development. A small increase in mRNA levels can be observed for some genes at very early stages of development (2 h). The main increase is observed between 4 and 16 h of development for all these genes, although the time course of mRNA accumulation is different for each one of the genes studied. Some other genes, like those coding for muscle actin (actin 3) or the Na+, K(+)-ATPase alpha-subunit isoform coded by the cDNA clone alpha 2850, are not expressed in the cyst before resumption of development and their expression is induced after 10 or 6 h of development, respectively. These data on the kinetic of mRNA accumulation provide the information required to determine transcriptionally active developmental stages, necessary to study in more detail the mechanisms of transcriptional regulation during activation of cryptobiotic cysts and resumption of embryonic development.
Erko Stackebrandt - One of the best experts on this subject based on the ideXlab platform.
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exiguobacterium mexicanum sp nov and exiguobacterium Artemiae sp nov isolated from the brine shrimp Artemia franciscana
Systematic and Applied Microbiology, 2006Co-Authors: Alejandro Lopezcortes, Peter Schumann, Rudiger Pukall, Erko StackebrandtAbstract:Abstract Two Gram-positive strains isolated from cysts of the brine shrimp Artemia franciscana were subjected to a polyphasic taxonomic analysis. Based on 16S rRNA gene sequence comparison and composition of isoprenoid quinones, peptidoglycan and fatty acids, these organisms are members of the genus Exiguobacterium. Both strains showed 95.9% 16S rRNA gene sequence similarity to one another. The 16S rRNA gene sequences of strain 8NT and 9ANT were 97.5% and 98.9% similar to those of Exiguobacterium aurantiacum DSM 6208T and Exiguobacterium undae DSM 14481T, respectively. Based on differences in chemotaxonomic and physiological characteristics, results of DNA–DNA hybridization and automated riboprinting, two novel species of the genus Exiguobacterium are proposed, Exiguobacterium mexicanum sp. nov. (type strain 8NT=DSM 16483T=CIP 108859T) and Exiguobacterium Artemiae sp. nov. (type strain 9ANT=DSM 16484T=CIP 108858T).
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exiguobacterium mexicanum sp nov and exiguobacterium Artemiae sp nov isolated from the brine shrimp Artemia franciscana
Systematic and Applied Microbiology, 2006Co-Authors: Alejandro Lopezcortes, Peter Schumann, Rudiger Pukall, Erko StackebrandtAbstract:Abstract Two Gram-positive strains isolated from cysts of the brine shrimp Artemia franciscana were subjected to a polyphasic taxonomic analysis. Based on 16S rRNA gene sequence comparison and composition of isoprenoid quinones, peptidoglycan and fatty acids, these organisms are members of the genus Exiguobacterium. Both strains showed 95.9% 16S rRNA gene sequence similarity to one another. The 16S rRNA gene sequences of strain 8NT and 9ANT were 97.5% and 98.9% similar to those of Exiguobacterium aurantiacum DSM 6208T and Exiguobacterium undae DSM 14481T, respectively. Based on differences in chemotaxonomic and physiological characteristics, results of DNA–DNA hybridization and automated riboprinting, two novel species of the genus Exiguobacterium are proposed, Exiguobacterium mexicanum sp. nov. (type strain 8NT=DSM 16483T=CIP 108859T) and Exiguobacterium Artemiae sp. nov. (type strain 9ANT=DSM 16484T=CIP 108858T).
Patrick Sorgeloos - One of the best experts on this subject based on the ideXlab platform.
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Impact of brine acidification on hatchability, survival and reproduction of Artemia parthenogenetica and Artemia franciscana in salt ponds, Bohai Bay, China
Chinese Journal of Oceanology and Limnology, 2014Co-Authors: Yuangao Deng, Patrick Sorgeloos, Jing Wang, Gilbert Van StappenAbstract:We studied the effect of pH (pH 5, 6, 7 and 8) on the hatching percentage, survival and reproduction of Artemia strains in Bohai Bay salt ponds. Strains included parthenogenetic Artemia from Bohai Bay (BHB), Artemia franciscana from San Francisco Bay, and A. franciscana artificially produced in salt ponds in Vietnam. The latter was included as a potential inoculum for biological management of salt ponds. The hatching percentage of cysts after 24 h and the survival rate of the tested Artemia strains were significantly reduced when exposed to a culture medium at pH 5 for 18 d (P
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Morphological characteristics of the digestive tract of gnotobiotic Artemia franciscana nauplii
Aquaculture, 2011Co-Authors: R.a.y.s. Asanka Gunasekara, Patrick Sorgeloos, Peter Bossier, Anamaria Rekecki, Pieter Cornillie, Maria Cornelissen, Paul Simoens, Wim Van Den BroeckAbstract:Abstract Cysts of Artemia franciscana were hatched and nauplii were reared under gnotobiotic conditions (gnotobiotic Artemia rearing system). Stereomicroscopy, computer assisted three-dimensional reconstruction, light microscopy, and transmission electron microscopy were used to study the structural and cellular morphology of their digestive tracts. The alimentary tract of gnotobiotic Artemia nauplii, fed with dead Aeromonas hydrophila and wild type strain of Saccharomyces cerevisiae , is a hooked, tubular structure which is composed of three clearly distinguishable parts, i.e. the foregut, midgut and hindgut that are freely suspended in haemolymph. The epithelium lining of the entire gut consists of a single cell layer. Enterocytes of the foregut and hindgut are cuboidal and lined by a thin cuticle, whereas midgut enterocytes are cuboidal to columnar and possess an apical brush border. The fore- and hindgut mainly display characteristics suggestive for mechanical functions, whereas the midgut shows characteristics of absorption, storage and secretion. The gnotobiotic Artemia rearing system is most useful to investigate the effects of micro-organisms on the development of nauplii. The knowledge acquired in this study potentially facilitates the evaluation of gut morphology when specific micro-organisms are introduced into the culture system, as compared to the gnotobiotic counterparts.
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short chain fatty acids protect gnotobiotic Artemia franciscana from pathogenic vibrio campbellii
Aquaculture, 2006Co-Authors: Tom Defoirdt, Patrick Sorgeloos, Peter Bossier, Dirk Halet, Willy VerstraeteAbstract:Infections caused by antibiotic resistant luminescent vibrios can cause considerable losses in aquaculture. In this study, different short-chain fatty acids were investigated as possible alternative biocontrol agents. The addition of 100 mM formic, acetic, propionic, butyric or valeric acid to the growth medium of a pathogenic Vibrio campbellii strain completely inhibited its growth at pH 6. At 10 mM, the growth of the pathogen was delayed, whereas at 1 mM, no effect could be observed. The growth-inhibitory effect was clearly pH-dependent and decreased with increasing pH. An in vivo challenge test with gnotobiotic Artemia franciscana nauplii revealed that all five short-chain fatty acids protected the shrimp from the pathogenic V. campbellii strain. The addition of 20 mM of the short-chain fatty acids to the culture water resulted in a significantly increased survival of infected nauplii, with no difference between the different fatty acids. In conclusion, our data indicate that short-chain fatty acids might be useful as alternative biocontrol agents to treat luminescent vibriosis
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quorum sensing disrupting brominated furanones protect the gnotobiotic brine shrimp Artemia franciscana from pathogenic vibrio harveyi vibrio campbellii and vibrio parahaemolyticus isolates
Applied and Environmental Microbiology, 2006Co-Authors: Tom Defoirdt, Roselien Crab, Patrick Sorgeloos, Thomas K Wood, Willy Verstraete, Peter BossierAbstract:Autoinducer 2 (AI-2) quorum sensing was shown before to regulate the virulence of Vibrio harveyi towards the brine shrimp Artemia franciscana. In this study, several different pathogenic V. harveyi, Vibrio campbellii, and Vibrio parahaemolyticus isolates were shown to produce AI-2. Furthermore, disruption of AI-2 quorum sensing by a natural and a synthetic brominated furanone protected gnotobiotic Artemia from the pathogenic isolates in in vivo challenge tests.
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International study on Artemia. LXII. Genomic relationships between Artemia franciscana and A. persimilis, inferred from chromocentre numbers
Heredity, 2001Co-Authors: Gonzalo Gajardo, John A. Beardmore, Patrick SorgeloosAbstract:International study on Artemia . LXII. Genomic relationships between Artemia franciscana and A. persimilis , inferred from chromocentre numbers
Peter Bossier - One of the best experts on this subject based on the ideXlab platform.
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Sequence and expression analysis of HSP70 family genes in Artemia franciscana
Scientific Reports, 2019Co-Authors: Wisarut Junprung, Stephanie De Vos, Parisa Norouzitallab, Anchalee Tassanakajon, Dung Nguyen Viet, Gilbert Van Stappen, Peter BossierAbstract:Thus far, only one gene from the heat shock protein 70 (HSP70) family has been identified in Artemia franciscana. Here, we used the draft Artemia transcriptome database to search for other genes in the HSP70 family. Four novel HSP70 genes were identified and designated heat shock cognate 70 (HSC70), heat shock 70 kDa cognate 5 (HSC70-5), Immunoglobulin heavy-chain binding protein (BIP), and hypoxia up-regulated protein 1 (HYOU1). For each of these genes, we obtained nucleotide and deduced amino acid sequences, and reconstructed a phylogenetic tree. Expression analysis revealed that in the juvenile state, the transcription of HSP70 and HSC70 was significantly (P 0.05) induction. Gene expression analysis demonstrated that not all members of the HSP70 family are involved in the response to heat stress and selection and that especially altered expression of HSC70 plays a role in a population selected for increased thermotolerance.
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Identification of RNAi-related genes and transgenerational efficiency of RNAi in Artemia franciscana
Aquaculture, 2019Co-Authors: Nguyen Viet Dung, Thomas H Macrae, Olivier Christiaens, Duy Le Van Bao, Stephanie De Vos, Guy Smagghe, Peter BossierAbstract:Abstract Artemia and the RNA interference technique were used in research to explore the function of genes in crustaceans. In this study, we annotated and characterized nine putative genes involved in RNA interference in Artemia franciscana including two Dicer, three Argonauts, two dsRNA binding proteins, Drosha and Sid-1 together with evidence of Pasha and Exportin-5. The phylogenetic results indicated the identity of these genes and revealed that genes homologous to those in both the siRNA and miRNA pathway in arthropods are also present in Artemia franciscana. This study provides the first look at the core genes of the RNAi machinery of A. franciscana. Additionally, egg-sac microinjection was used to generate the desired RNAi phenotype. The high numbers of nauplii with the desired phenotypes obtained from injected maternal A. franciscana (both from the first and second brood) demonstrated the reliability of the egg-sac microinjection method, providing a methodology to study gene function on high numbers of individuals be treating the parental generation.
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Morphological characteristics of the digestive tract of gnotobiotic Artemia franciscana nauplii
Aquaculture, 2011Co-Authors: R.a.y.s. Asanka Gunasekara, Patrick Sorgeloos, Peter Bossier, Anamaria Rekecki, Pieter Cornillie, Maria Cornelissen, Paul Simoens, Wim Van Den BroeckAbstract:Abstract Cysts of Artemia franciscana were hatched and nauplii were reared under gnotobiotic conditions (gnotobiotic Artemia rearing system). Stereomicroscopy, computer assisted three-dimensional reconstruction, light microscopy, and transmission electron microscopy were used to study the structural and cellular morphology of their digestive tracts. The alimentary tract of gnotobiotic Artemia nauplii, fed with dead Aeromonas hydrophila and wild type strain of Saccharomyces cerevisiae , is a hooked, tubular structure which is composed of three clearly distinguishable parts, i.e. the foregut, midgut and hindgut that are freely suspended in haemolymph. The epithelium lining of the entire gut consists of a single cell layer. Enterocytes of the foregut and hindgut are cuboidal and lined by a thin cuticle, whereas midgut enterocytes are cuboidal to columnar and possess an apical brush border. The fore- and hindgut mainly display characteristics suggestive for mechanical functions, whereas the midgut shows characteristics of absorption, storage and secretion. The gnotobiotic Artemia rearing system is most useful to investigate the effects of micro-organisms on the development of nauplii. The knowledge acquired in this study potentially facilitates the evaluation of gut morphology when specific micro-organisms are introduced into the culture system, as compared to the gnotobiotic counterparts.
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Evaluation of probiotic effect of Aeromonas hydrophila on the development of the digestive tract of germ-free Artemia franciscana nauplii
Journal of Experimental Marine Biology and Ecology, 2010Co-Authors: R.a.y.s. Asanka Gunasekara, Peter Bossier, Anamaria Rekecki, Kartik Baruah, Wim Van Den BroeckAbstract:Abstract Gnotobiotic model systems are attracting attention as they facilitate the unraveling of mechanisms involved in host–microbe interactions. Here morphological and stereological tools were incorporated to contribute to the study on the mode of action of putative probiotic bacteria. In this study, the effect of live probiotic bacteria on the early development of the digestive tract of gnotobiotic Artemia franciscana was investigated. Germ-free Artemia nauplii were cultured for 6 days using Baker's yeast and dead Aeromonas hydrophila (LVS3, a putative probiotic strain for Artemia franciscana) as major feed sources. For the other group, live Aeromonas hydrophila was added on day 1 (day of hatching), while all the other parameters were analogous to the germ-free group. The survival on day 6 was significantly higher in the group in which live probiotic bacteria were used than in the control group. Individual length and total biomass production were always significantly larger in the same group. Midgu volume/individual length and the midgut length/individual length were not significantly different between both groups on all the sampling points. Hindgut volume/individual length and the hindgut length/individual length were not significantly different between both the groups on days 2 and 4 while those were significantly larger at day 6 in the cultures fed with live bacteria, suggesting that live bacteria have a positive effect on cell proliferation in the gut. However, the morphology of the mid- and the hindgut did not show important differences between both groups.
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short chain fatty acids protect gnotobiotic Artemia franciscana from pathogenic vibrio campbellii
Aquaculture, 2006Co-Authors: Tom Defoirdt, Patrick Sorgeloos, Peter Bossier, Dirk Halet, Willy VerstraeteAbstract:Infections caused by antibiotic resistant luminescent vibrios can cause considerable losses in aquaculture. In this study, different short-chain fatty acids were investigated as possible alternative biocontrol agents. The addition of 100 mM formic, acetic, propionic, butyric or valeric acid to the growth medium of a pathogenic Vibrio campbellii strain completely inhibited its growth at pH 6. At 10 mM, the growth of the pathogen was delayed, whereas at 1 mM, no effect could be observed. The growth-inhibitory effect was clearly pH-dependent and decreased with increasing pH. An in vivo challenge test with gnotobiotic Artemia franciscana nauplii revealed that all five short-chain fatty acids protected the shrimp from the pathogenic V. campbellii strain. The addition of 20 mM of the short-chain fatty acids to the culture water resulted in a significantly increased survival of infected nauplii, with no difference between the different fatty acids. In conclusion, our data indicate that short-chain fatty acids might be useful as alternative biocontrol agents to treat luminescent vibriosis
Thomas H Macrae - One of the best experts on this subject based on the ideXlab platform.
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Identification of RNAi-related genes and transgenerational efficiency of RNAi in Artemia franciscana
Aquaculture, 2019Co-Authors: Nguyen Viet Dung, Thomas H Macrae, Olivier Christiaens, Duy Le Van Bao, Stephanie De Vos, Guy Smagghe, Peter BossierAbstract:Abstract Artemia and the RNA interference technique were used in research to explore the function of genes in crustaceans. In this study, we annotated and characterized nine putative genes involved in RNA interference in Artemia franciscana including two Dicer, three Argonauts, two dsRNA binding proteins, Drosha and Sid-1 together with evidence of Pasha and Exportin-5. The phylogenetic results indicated the identity of these genes and revealed that genes homologous to those in both the siRNA and miRNA pathway in arthropods are also present in Artemia franciscana. This study provides the first look at the core genes of the RNAi machinery of A. franciscana. Additionally, egg-sac microinjection was used to generate the desired RNAi phenotype. The high numbers of nauplii with the desired phenotypes obtained from injected maternal A. franciscana (both from the first and second brood) demonstrated the reliability of the egg-sac microinjection method, providing a methodology to study gene function on high numbers of individuals be treating the parental generation.
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Knockdown of the small heat-shock protein p26 by RNA interference modifies the diapause proteome of Artemia franciscana
Biochemistry and Cell Biology, 2019Co-Authors: Hajer Salem Malitan, Alejandro Cohen, Thomas H MacraeAbstract:Embryos of the crustacean Artemia franciscana may arrest as gastrulae, forming cysts that enter diapause, which is a state of reduced metabolism and enhanced stress tolerance. Diapausing cysts surv...
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A Molecular Overview of Diapause in Embryos of the Crustacean, Artemia franciscana
Dormancy and Resistance in Harsh Environments, 2010Co-Authors: Zhijun Qiu, Thomas H MacraeAbstract:Diapause-destined embryos of Artemia franciscana arrest as gastrulae and are enclosed within a chitinous shell to form cysts. Upon release from females encysted embryos enter diapause, becoming essentially ametabolic and very stress tolerant. An objective of our research is to characterize the molecular mechanisms of diapause initiation and maintenance. Subtractive hybridization was therefore used to identify up-regulated genes in diapause-destined Artemia embryos and these were divided into functional categories including cellular growth and stress tolerance, metabolism, and genetic and environmental information processing. Of particular interest mRNA for p8, a stress-inducible transcription co-factor, increased early in diapause-destined Artemia embryos, representing one of the few transcription co-factors known to be up-regulated during diapause. mRNAs encoding the three small heat shock proteins p26, ArHsp21, and ArHsp22 were also up-regulated and these proteins may promote diapause maintenance by enhancing stress tolerance. The work has revealed proteins potentially crucial to diapause, a physiological condition of fundamental and applied significance.
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Gene expression in diapause-destined embryos of the crustacean, Artemia franciscana.
Mechanisms of Development, 2007Co-Authors: Zhijun Qiu, Stephen Tsoi, Thomas H MacraeAbstract:Diapause-destined embryos of the crustacean Artemia franciscana cease development as gastrulae, encyst, and enter a resting stage characterized by greatly reduced metabolic activity and extreme stress resistance. To better understand diapause induction and maintenance in Artemia embryos gene expression was analyzed by subtractive hybridization at two days post-fertilization, a time early in this developmental process. Eighty-five of 264 cDNA clones sequenced matched GenBank entries and they fell into categories designated as environmental information processing, cellular processes, genetic information processing and metabolism. Semi-quantitative RT-PCR of cDNAs populating the subtractive library identified seventeen up-regulated and four down-regulated transcripts, the former including those encoding a human transcription cofactor homologue, three small heat shock proteins, putative cell growth suppressor proteins and several enzymes. As examples, p8 may modulate gene expression during diapause in Artemia embryos. BRCA1 associated protein-1 (BAP1) and other functionally related proteins may influence cell growth and division during transition into diapause, a time when these processes are inhibited, whereas small heat shock proteins protect embryos from stress. This study represents the first systematic molecular characterization of diapause in crustaceans. Several differentially expressed genes were identified, expanding the repertoire of proteins potentially modified during diapause and suggesting mechanistic pathways indigenous to the initiation and maintenance of this physiological state.
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Preparation and characterization of posttranslationally modified tubulins from Artemia franciscana.
Methods in molecular medicine, 2007Co-Authors: Paul A. O'connell, Thomas H MacraeAbstract:Tubulin heterogeneity within eukaryotic cells is generated by differential gene expression and posttranslational modification of alpha- and beta-tubulin gene products, either as heterodimers or when polymerized into microtubules. The characterization of posttranslationally modified tubulins from the crustacean Artemia franciscana is presented, although tubulins from other sources can be studied with these procedures. Tubulin is prepared from cell free extracts by taxol-induced assembly and centrifugation of microtubules through sucrose cushions, which also yields microtubule-associated proteins, or it is purified to apparent homogeneity by relatively simple chromatographic procedures and assembly/disassembly steps. To detect posttranslationally modified tubulins protein samples are electrophoresed in sodium dodecyl sulfate (SDS) polyacrylamide gels, blotted to nitrocellulose membranes and probed with isoform-specific antibodies. Isotubulins, for which gene-encoded amino acid differences and posttranslational modifications generate charge variations, are resolved in two-dimensional gels using isoelectric focusing followed by SDS polyacrylamide gel electrophoresis, a procedure useful for resolution of microtubule-associated proteins. Isoforms patterns are visualized by Coomassie blue and/or silver staining and individual isoforms are identified by antibody reactivity on Western blots. Tubulin isoforms are localized in Artemia by immunofluorescent staining of larvae. The focus of this chapter is the purification of tubulin from a nonneural source and characterization of tyrosinated, detyrosinated, and nontyrosinatable alpha-tubulins using polyclonal antibodies made to carboxy-terminal peptides of each isoform.
