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1.
Eur J Protistol ; 72: 125643, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31734636

RESUMO

The colonization features of periphytic protozoa have proved to be a useful tool for indicating water quality status in aquatic ecosystems. In order to reveal the seasonal variations in colonization dynamics of the protozoa, a 1-year baseline survey was carried out in coastal waters of the Yellow Sea, northern China. Using glass slides as artificial substrates, a total of 240 slides were collected at a depth of 1 m in four seasons after colonization periods of 3, 7, 10, 14, 21, and 28 days. A total of 122 ciliate species were identified with 21 dominant species. The colonization dynamics of the protozoa were well fitted to the MacArthur-Wilson and logistic models in all four seasons (P < 0.05). However, the equilibrium species numbers (Seq), colonization rates (G), and the time to 90% Seq (T90%) represented a clear seasonal variability: (1) more or less similar levels in spring and autumn (Seq = 29/23; G = 0.301/0.296; T90%=7.650/7.779); (2) with a significant difference in summer and winter (Seq = 32/121; G = 0.708/0.005; T90% = 3.252/479.705). Multivariate approaches demonstrated that the exposure time for the species composition and community structure of the protozoa to an equilibrium period were 10-14 days in spring and autumn, but less and more time periods were needed in summer and winter, respectively. Based on the results, we suggest that the colonization dynamics of periphytic protozoa were different within four seasons, and an optimal sampling strategy for monitoring surveys should be modified during different seasons in marine ecosystems.


Assuntos
Biodiversidade , Cilióforos/fisiologia , Estações do Ano , Água do Mar/parasitologia , China , Monitoramento Ambiental , Modelos Logísticos
2.
Fish Shellfish Immunol ; 94: 661-674, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31521785

RESUMO

The yellow drum Nibea albiflora is less susceptible to Cryptocaryon irritans infection than is the case with other marine fishes such as Larimichthys crocea, Lateolabrax japonicus, and Pagrus major. To investigate further their resistance mechanism, we infected the N. albiflora with the C. irritans at a median lethal concentration of 2050 theronts/g fish. The skins of the infected and the uninfected fishes were sampled at 24 h and 72 h followed by an extensive analysis of metabolism. The study results revealed that there were 2694 potential metabolites. At 24 h post-infection, 12 metabolites were up-regulated and 17 were down-regulated whereas at 72 h post-infection, 22 metabolites were up-regulated and 26 were down-regulated. Pathway enrichment analysis shows that the differential enriched pathways were higher at 24 h with 22 categories and 58 subcategories (49 up, 9 down) than at 72 h whereby the differential enriched pathways were 6 categories and 8 subcategories (4 up, 4 down). In addition, the principal component analysis (PCA) plot shows that at 24 h the metabolites composition of infected group were separately clustered to uninfected group while at 72 h the metabolites composition in infected group were much closer to uninfected group. This indicated that C. irritans caused strong metabolic stress on the N. albiflora at 24 h and restoration of the dysregulated metabolic state took place at 72 h of infection. Also, at 72 h post infection a total of 17 compounds were identified as potential biomarkers. Furthermore, out of 2694 primary metabolites detected, 23 metabolites could be clearly identified and semi quantified with a known identification number and assigned into 66 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Most of the enriched KEGG pathways were mainly from metabolic pathway classes, including the metabolic pathway, biosynthesis of secondary metabolites, taurine and hypotaurine metabolism, purine metabolism, linoleic acid metabolism, phenylalanine, tyrosine and tryptophan biosynthesis. Others were glyoxylate and dicarboxylate metabolism, glutathione metabolism, and alanine, aspartate, and glutamate metabolism. Moreover, out of the identified metabolites, only 6 metabolites were statistically differentially expressed, namely, L -glutamate (up-regulated) at 24 h was important for energy and precursor for other glutathiones and instruments of preventing oxidative injury; 15-hydroxy- eicosatetraenoic acid (15-HETE), (S)-(-)-2-Hydroxyisocaproic acid, and adenine (up-regulated) at 72 h were important for anti-inflammatory and immune responses during infection; others were delta-valerolactam and betaine which were down-regulated compared to uninfected group at 72 h, might be related to immure responses including stimulation of immune system such as production of antibodies. Our results therefore further advance our understanding on the immunological regulation of N. albiflora during immune response against infections as they indicated a strong relationship between skin metabolome and C. irritans infection.


Assuntos
Infecções por Cilióforos/veterinária , Doenças dos Peixes/imunologia , Imunidade Inata/imunologia , Metaboloma/imunologia , Perciformes , Pele/imunologia , Animais , Cilióforos/fisiologia , Infecções por Cilióforos/imunologia , Infecções por Cilióforos/parasitologia , Doenças dos Peixes/parasitologia
3.
Fish Shellfish Immunol ; 93: 863-870, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31422178

RESUMO

Interleukins (ILs) are a subgroup of cytokines, which are molecules involved in the intercellular regulation of the immune system. These cytokines have been extensively studied in mammalian models, but systematic analyses of fish are limited. In the current study, 3 IL genes from golden pompano (Trachinotus ovatus) were characterized. The IL-1ß protein contains IL-1 family signature motif, and four long helices (αA - αD) in IL-11 and IL-34, which were well conserved. All 3 ILs clustered phylogenetically with their respective IL relatives in mammalian and other teleost species. Under normal physiological conditions, the expression of IL-1ß, IL-11, and IL-34 were detected at varied levels in the 11 tissues examined. Most of the 3 ILs examined were highly expressed in liver, spleen, kidney, gill, or skin. Following pathogenic bacterial, viral, or parasitic challenge, IL-1ß, IL-11, and IL-34 exhibited distinctly different expression profiles in a time-, tissue-, and pathogen-dependent manner. In general, IL-1ß was expressed at higher levels following challenge with all pathogens examined than was observed for IL-11 and IL-34. Furthermore, Streptococcus agalactiae and Cryptocaryon irritans caused higher levels of IL-1ß and IL-11 expression than Vibrio harveyi and viral nervous necrosis virus (VNNV). The increased expression of IL-34 caused by VNNV and C. irritans were higher than that caused by V. harveyi and S. agalactiae. These results suggest that these 3 ILs in T. ovatus may play different effect pathogen type specific responses.


Assuntos
Doenças dos Peixes/imunologia , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Peixes/imunologia , Regulação da Expressão Gênica/imunologia , Imunidade Inata/genética , Animais , Cilióforos/fisiologia , Infecções por Cilióforos/imunologia , Infecções por Cilióforos/veterinária , Perfilação da Expressão Gênica/veterinária , Interleucina-11/genética , Interleucina-11/imunologia , Interleucina-1beta/genética , Interleucina-1beta/imunologia , Interleucinas/genética , Interleucinas/imunologia , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/veterinária , Streptococcus agalactiae/fisiologia , Vibrio/fisiologia , Vibrioses/imunologia , Vibrioses/veterinária
4.
Nature ; 571(7766): 560-564, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31292551

RESUMO

The biophysical relationships between sensors and actuators1-5 have been fundamental to the development of complex life forms. Swimming organisms generate abundant flows that persist in aquatic environments6-13, and responding promptly to external stimuli is key to survival14-19. Here we present the discovery of 'hydrodynamic trigger waves' in cellular communities of the protist Spirostomum ambiguum that propagate-in a manner similar to a chain reaction20-22-hundreds of times faster than their swimming speed. By coiling its cytoskeleton, Spirostomum can contract its long body by 60% within milliseconds23, experiencing accelerations that can reach forces of 14g. We show that a single cellular contraction (the transmitter) generates long-ranged vortex flows at intermediate Reynolds numbers that can, in turn, trigger neighbouring cells (the receivers). To measure the sensitivity to hydrodynamic signals in these receiver cells, we present a high-throughput suction-flow device for probing mechanosensitive ion channels24 by back-calculating the microscopic forces on the cell membrane. We analyse and quantitatively model the ultra-fast hydrodynamic trigger waves in a universal framework of antenna and percolation theory25,26, and reveal a phase transition that requires a critical colony density to sustain collective communication. Our results suggest that this signalling could help to organize cohabiting communities over large distances and influence long-term behaviour through gene expression (comparable to quorum sensing16). In more immediate terms, because contractions release toxins27, synchronized discharges could facilitate the repulsion of large predators or immobilize large prey. We postulate that numerous aquatic organisms other than protists could coordinate their behaviour using variations of hydrodynamic trigger waves.


Assuntos
Comunicação Celular , Cilióforos/citologia , Cilióforos/fisiologia , Hidrodinâmica , Natação/fisiologia , Movimentos da Água , Animais , Organismos Aquáticos/citologia , Organismos Aquáticos/genética , Organismos Aquáticos/fisiologia , Biofísica , Cilióforos/genética , Citoesqueleto/fisiologia , Comportamento Predatório , Reologia , Fatores de Tempo
5.
Fish Shellfish Immunol ; 92: 690-697, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31276788

RESUMO

Macrophage expressed gene 1 (Mpeg1) is a molecule that can form pores and destroy the cell membrane of invading pathogens. In this study, we identified two Mpeg1 isoforms from the orange-spotted grouper (Epinephelus coioides) and named them EcMpeg1a and EcMpeg1b. Predicted proteins of the two EcMpeg1s contained a signal peptide, a conserved membrane attack complex/perforin (MACPF) domain, a transmembrane segment, and an intracellular region. Sequence alignment demonstrated that two EcMpeg1 proteins share a high sequence identity with that of other teleosts. Tissue distribution analysis showed that EcMpeg1s were expressed in all tissues tested in healthy grouper, with the highest expression in the head kidney and spleen. After infection with the ciliate parasite Cryptocaryon irritans, expression of the two EcMpeg1s was significantly upregulated in the spleen and gills. Furthermore, the recombinant EcMpeg1a showed antiparasitic and antibacterial activity against Gram-negative and -positive bacteria, whereas EcMpeg1b had an inhibitory effect only against Gram-positive bacteria. These results indicated that EcMpeg1s play an important role in the host response against invading pathogens.


Assuntos
Bass/genética , Bass/imunologia , Doenças dos Peixes/imunologia , Regulação da Expressão Gênica/imunologia , Imunidade Inata/genética , Proteínas de Membrana/genética , Proteínas de Membrana/imunologia , Sequência de Aminoácidos , Animais , Cilióforos/fisiologia , Infecções por Cilióforos/imunologia , Infecções por Cilióforos/veterinária , Proteínas de Peixes/química , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Perfilação da Expressão Gênica/veterinária , Bactérias Gram-Negativas/fisiologia , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/veterinária , Bactérias Gram-Positivas/fisiologia , Infecções por Bactérias Gram-Positivas/imunologia , Infecções por Bactérias Gram-Positivas/veterinária , Proteínas de Membrana/química , Filogenia , Alinhamento de Sequência/veterinária
6.
Fish Shellfish Immunol ; 93: 308-312, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31352113

RESUMO

Initiation of the innate immune response requires recognition of pathogen-associated molecular patterns by pathogen recognition receptors such as Toll-like receptors (TLRs). MyD88 adaptor-like (Mal) is an adaptor that responds to TLR activation and acts as a bridging adaptor for MyD88. In the present study, the open reading frame of Mal was identified in orange-spotted grouper (Epinephelus coioides), and named EcMal. It contained 831 bp encoding 276 aa, and was encoded by a 1299 bp DNA sequence with three exons and two introns. EcMal and the Mal sequence of other species shared different degrees of sequence identity, and clustered into the same group. EcMal was distributed in all tissues tested in healthy grouper, with the highest expression level in the head kidney. After infection with Cryptocaryon irritans, the expression level of EcMal was up-regulated in the gill and spleen. In addition, EcMal exhibited global cytosolic and nucleus localization, and could significantly activate NF-κB activity in grouper spleen cells.


Assuntos
Bass/genética , Bass/imunologia , Doenças dos Peixes/imunologia , Regulação da Expressão Gênica/imunologia , Imunidade Inata/genética , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/imunologia , Sequência de Aminoácidos , Animais , Cilióforos/fisiologia , Infecções por Cilióforos/imunologia , Infecções por Cilióforos/veterinária , Proteínas de Peixes/química , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Perfilação da Expressão Gênica/veterinária , Fator 88 de Diferenciação Mieloide/química , Filogenia , Alinhamento de Sequência/veterinária
7.
Mar Pollut Bull ; 142: 452-456, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31232323

RESUMO

To identify the influence of tidal events on community functioning of periphytic ciliates for monitoring program and community research using biological trait analysis, a 3-month baseline survey was conducted in Korean coastal waters using the polyurethane foam enveloped slide system (PFES) and conventional slide system (CS). Although the periphytic ciliate communities had similar biological trait categories, they represented considerable differences in community functioning and functional diversity measures within the PFES and CS systems. Multivariate analyses revealed different ways of the temporal shift in community functioning of the ciliates in both systems. The dispersion analysis demonstrated that the CS system was sensitive to the strong disturbance of tidal current and circulation compared to the PFES system. These findings suggest that the strong tidal event may significantly influence the output of analysis on community functioning of periphytic ciliates for bioassessment in marine ecosystems.


Assuntos
Cilióforos/fisiologia , Monitoramento Ambiental/métodos , Água do Mar , Ecossistema , Monitoramento Ambiental/instrumentação , Análise Multivariada , Fenótipo , República da Coreia
8.
Protist ; 170(3): 283-286, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31181471

RESUMO

Many protists form cell colonies. Among them several are filter-feeders depending on suspended food particles such as bacteria. It has been suggested that the formation of colonies enhances feeding efficiency and implied that - in the case of colonial choanoflagellates - it was an adaptive trait that led to the evolution of metazoans. Here it is shown experimentally - for a colonial peritrich ciliate and for a choanoflagellate - that colony-formation does not enhance the efficiency of filter-feeding relative to solitary cells and that the adaptive significance of cell colony-formation must have some other explanation.


Assuntos
Coanoflagelados/fisiologia , Cilióforos/fisiologia , Coanoflagelados/citologia , Cilióforos/citologia , Comportamento Alimentar/fisiologia
9.
Arch Microbiol ; 201(7): 889-896, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30968220

RESUMO

Differences in the rumen bacterial community have been previously reported for Soay sheep housed under different day length conditions. This study extends this previous investigation to other organs of the digestive tract, as well as the analysis of ciliated protozoa and anaerobic fungi. The detectable concentrations of ciliated protozoa and anaerobic fungi decreased with increased day length in both the rumen and large colon, unlike those of bacteria where no effect was observed. Conversely, bacterial community composition was affected by day length in both the rumen and large colon, but the community composition of the detectable ciliated protozoa and anaerobic fungi was not affected. Day length-associated differences in the bacterial community composition extended to all of the organs examined, with the exception of the duodenum and the jejunum. It is proposed that differences in rumen fill and ruminal 'by-pass' nutrients together with endocrinological changes cause the observed effects of day length on the different gut microbial communities.


Assuntos
Ingestão de Alimentos/efeitos da radiação , Microbioma Gastrointestinal/efeitos da radiação , Trato Gastrointestinal/microbiologia , Microbiota/efeitos da radiação , Carneiro Doméstico/microbiologia , Carneiro Doméstico/parasitologia , Luz Solar , Animais , Fenômenos Fisiológicos Bacterianos , Cilióforos/fisiologia , Fungos/fisiologia , Trato Gastrointestinal/parasitologia , Ovinos , Fatores de Tempo
10.
Eur J Protistol ; 68: 108-120, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30826731

RESUMO

Paramecium strains with the ability to kill other paramecia often harbour intracellular bacteria belonging to the genera Caedibacter or Caedimonas. Central structures of this killer trait are refractile bodies (R-bodies) produced by the endosymbionts. Once ingested by a sensitive Paramecium, R-bodies presumably act as delivery system for an unidentified toxin which causes the death of endosymbiont-free paramecia while those infected gain resistance from their symbionts. The killer trait is therefore considered as competitive advantage for the hosts of R-body producers. While its effectiveness against paramecia is well documented, the effects on other aquatic ciliates are much less studied. In order to address the broadness of the killer trait, a reproducible killer test assay considering the effects on predatory ciliates (Climacostomum virens and Dileptus jonesi) as well as potential bacterivorous Paramecium competitors (Dexiostoma campyla, Euplotes aediculatus, Euplotes woodruffi, and Spirostomum teres) as possibly susceptible species was established. All used organisms were molecularly characterized to increase traceability and reproducibility. The absence of any lethal effects in both predators and competitors after exposure to killer paramecia strongly suggests a narrow action range for the killer trait. Thus, R-body producing bacteria provide their host with a complex, costly strategy to outcompete symbiont-free congeners only.


Assuntos
Bactérias/metabolismo , Fenômenos Fisiológicos Bacterianos , Cilióforos/microbiologia , Cilióforos/fisiologia , Microbiologia da Água , Água Doce , Paramecium/microbiologia , Paramecium/fisiologia
11.
Fish Shellfish Immunol ; 87: 730-736, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30769079

RESUMO

Tumor necrosis factor receptor-associated factor 5 (TRAF5) is a key adapter molecule that participates in numerous signaling pathways. The function of TRAF5 in fish is largely unknown. In the present study, a TRAF5 cDNA sequence (EcTRAF5) was identified in grouper (Epinephelus coioides). Similar to its mammalian counterpart, EcTRAF5 contained an N-terminal RING finger domain, a zinc finger domain, a C-terminal TRAF domain, including a coiled-coil domain and a MATH domain. The EcTRAF5 protein shared relatively low sequence identity with that of other species, but clustered with TRAF5 sequences from other fish. Real-time PCR analysis revealed that EcTRAF5 mRNA was broadly expressed in numerous tissues, with relatively high expression in skin, hindgut, and head kidney. Additionally, the expression of EcTRAF5 was up-regulated in gills and head kidney after infection with Cryptocaryon irritans. Intracellular localization analysis demonstrated that the full-length EcTRAF5 protein was uniformly distributed in the cytoplasm; while a deletion mutant of the coiled-coil domain of EcTRAF5 was observed uniformly distributed in the cytoplasm and the nucleus. After exogenous expression in HEK293T cells, TRAF5 significantly activated NF-κB. The deletion of the EcTRAF5 RING domain or of the zinc finger domain dramatically impaired its ability to activate NF-κB, implying that the RING domain and the zinc finger domain are required for EcTRAF5 signaling.


Assuntos
Bass/genética , Bass/imunologia , Doenças dos Peixes/imunologia , Regulação da Expressão Gênica/imunologia , Imunidade Inata/genética , Fator 5 Associado a Receptor de TNF/genética , Fator 5 Associado a Receptor de TNF/imunologia , Sequência de Aminoácidos , Animais , Cilióforos/fisiologia , Infecções por Cilióforos/imunologia , Infecções por Cilióforos/veterinária , Proteínas de Peixes/química , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Perfilação da Expressão Gênica/veterinária , Filogenia , Alinhamento de Sequência/veterinária , Transdução de Sinais , Fator 5 Associado a Receptor de TNF/química
12.
ISME J ; 13(5): 1360-1369, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30647459

RESUMO

The single-celled ciliate Paramecium bursaria is an indispensable model for investigating endosymbiosis between protists and green-algal symbionts. To elucidate the mechanism of this type of endosymbiosis, we combined PacBio and Illumina sequencing to assemble a high-quality and near-complete macronuclear genome of P. bursaria. The genomic characteristics and phylogenetic analyses indicate that P. bursaria is the basal clade of the Paramecium genus. Through comparative genomic analyses with its close relatives, we found that P. bursaria encodes more genes related to nitrogen metabolism and mineral absorption, but encodes fewer genes involved in oxygen binding and N-glycan biosynthesis. A comparison of the transcriptomic profiles between P. bursaria with and without endosymbiotic Chlorella showed differential expression of a wide range of metabolic genes. We selected 32 most differentially expressed genes to perform RNA interference experiment in P. bursaria, and found that P. bursaria can regulate the abundance of their symbionts through glutamine supply. This study provides novel insights into Paramecium evolution and will extend our knowledge of the molecular mechanism for the induction of endosymbiosis between P. bursaria and green algae.


Assuntos
Chlorella/microbiologia , Cilióforos/microbiologia , Paramecium/fisiologia , Simbiose , Chlorella/fisiologia , Cilióforos/fisiologia , Paramecium/genética , Paramecium/isolamento & purificação , Filogenia
13.
Dev Comp Immunol ; 90: 152-156, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30248360

RESUMO

Transforming growth factor-ß activated kinase 1 (TAK1) is a crucial signal transducer in multiple signaling pathways. TAK1 binds TAB1, TAB2, and TAB3, which act as activators and adaptors that specifically regulate the activation of TAK1. To date, the role of TABs is largely unknown in fish. In the present study, a TAB1 cDNA sequence was identified in grouper (Epinephelus coioides), and designated EcTAB1. The full-length open reading frame of EcTAB1 is 1, 521 bp; it encodes 506 amino acids that contains an N-terminal PP2C domain. Many important functional sites in mammalian TAB1 were conserved in TAB1 from grouper and from other fish. Multiple sequence alignment showed that EcTAB1 protein shared high sequence identity with TAB1 of other fish, especially with Stegastes partitus (95% identity). TAB1 was clustered into the same subgroup with other fish TAB1 in the phylogenetic tree. Tissue expression analysis indicated that TAB1 was widely distributed in different tissues. After infection with Cryptocaryon irritans, EcTAB1 expression was up-regulated in the infection site (gills). Besides, EcTAB1 was expressed throughout the grouper spleen (GS) cells and significantly enhanced the activation of NF-κB.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Infecções por Cilióforos/imunologia , Cilióforos/fisiologia , Doenças dos Peixes/imunologia , Proteínas de Peixes/genética , Brânquias/imunologia , Perciformes/imunologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Clonagem Molecular , Proteínas de Peixes/metabolismo , Brânquias/parasitologia , Humanos , NF-kappa B/metabolismo , Membro 2 do Grupo C da Subfamília 2 de Receptores Nucleares/metabolismo , Filogenia , Alinhamento de Sequência , Transdução de Sinais , Regulação para Cima
14.
Dev Comp Immunol ; 92: 43-49, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30359623

RESUMO

Chemical drugs, such as antibiotics, were still important materials to prevent and cure diseases of aquatic organisms. However, antibiotics abuse do not only make the effects little, but also cause other bad problems, such as bacterial resistance and drug residues. Therefore, seeking the effective substitutes of antibiotics was an approach needed to be explored. Antibacterial peptides (AMPs) attracted more and more attention in the recent years. The parasitism and secondary bacterial invasion caused by ectroparasite Cryptocaryon irritans was a disaster to almost all host fish, including Larimichthys crocea. Reports indicated many AMPs played a key role in the whole parasitic infection cycle. Piscidin 5 like was a member of piscidin family. In the study, the antibacterial activity and mechanisms of piscidin 5 like from L.coreca (Lc-P5L) were detected. Liquid growth inhibition results showed recombinant Lc-P5L (rLc-P5L) had broad antibacterial spectrum and strong bactericidal activity. The bactericidal activity functioned in dose- and time-dependent manners. SEM (scanning electron microscope) observed the relatively detailed bactericidal process, rLc-P5L treatment resulted in a mass of bacteria piling together, appearing plenty of strange filaments and covering on the bacteria. Besides, S.aureus overgrowed plenty of granules, formed holes on the membrane of a few cells, and contents poured out from the holes. At the same time, antibacterial mechanisms were explored. After direct incubation with bacteria, western blot detected the apparently positive signal of rLc-P5L on bacteria; secondly, the incubation first with LPS (lipopolysaccharide) or LTA (lipoteichoic acid) significantly affect the binding of rLc-P5L to bacteria again, which indicated rLc-P5L could bind to bacteria through interaction with some PAMPs (pathogen-associated molecular patterns). In addition, rLc-P5L could interact with bacterial genome DNA by dose- and time-dependent means. In summary, rLc-P5L binded to bacteria surface through targeting to some PAMPs to damage membrane, and entered into cells to interact with genome DNA to disturb normal metabolism when it reached to some certain time and concentration thresholds, which were likely to be its pathway to exert antibacterial activity.


Assuntos
Peptídeos Catiônicos Antimicrobianos/metabolismo , Infecções por Cilióforos/imunologia , Doenças dos Peixes/imunologia , Proteínas de Peixes/metabolismo , Perciformes/imunologia , Infecções Estafilocócicas/imunologia , Staphylococcus aureus/fisiologia , Animais , Peptídeos Catiônicos Antimicrobianos/genética , Cilióforos/fisiologia , Proteínas de Peixes/genética , Padrões Moleculares Associados a Patógenos/metabolismo , Ligação Proteica
15.
Fish Shellfish Immunol ; 84: 726-732, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30393173

RESUMO

In mammals, tumor necrosis factor receptor-associated factor 2 (TRAF2) is a crucial intracellular adaptor protein, which performs a vital role in numerous signaling pathways that activate NF-κB, MAPKs, and IRFs. In the present study, three TRAF2 sequences were identified from the orange-spotted grouper (Epinephelus coioides), and named EcTRAF2-1, EcTRAF2-2, and EcTRAF2-3. These sequences contained conserved structure features that were similar to those of mammals. EcTRAF2-1 shared relatively low sequence identity with the other two EcTRAF2s. In healthy E. coioides, EcTRAF2s were widely expressed in all tissues tested, but with distinct expression profiles. After infection with Cryptocaryon irritans, EcTRAF2s was markedly upregulated in the gill and head kidney at most time points, implying that EcTRAF2s may be involved in host defense against C. irritans infection. In HEK293T cells, EcTRAF2s were scattered in the cytoplasm. EcTRAF2-1 and EcTRAF2-2 increased the activity of NF-κB, while EcTRAF2-3 reduced NF-κB activation mediated by EcTRAF2-1 implying that EcTRAF2-3 might be a negative regulator of EcTRAF2-1.


Assuntos
Bass/genética , Bass/imunologia , Doenças dos Peixes/imunologia , Regulação da Expressão Gênica/imunologia , Imunidade Inata/genética , Fator 2 Associado a Receptor de TNF/genética , Animais , Cilióforos/fisiologia , Infecções por Cilióforos/imunologia , Infecções por Cilióforos/veterinária , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Perfilação da Expressão Gênica/veterinária , Células HEK293 , Humanos , Filogenia , Distribuição Aleatória , Fator 2 Associado a Receptor de TNF/metabolismo
16.
Microb Ecol ; 78(1): 232-242, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30411190

RESUMO

Symbioses between prokaryotes and microbial eukaryotes, particularly ciliated protists, have been studied for a long time. Nevertheless, researchers have focused only on a few host genera and species, mainly due to difficulties in cultivating the hosts, and usually have considered a single symbiont at a time. Here, we present a pilot study using a single-cell microbiomic approach to circumvent these issues. Unicellular ciliate isolation followed by simultaneous amplification of eukaryotic and prokaryotic markers was used. Our preliminary test gave reliable and satisfactory results both on samples collected from different habitats (marine and freshwater) and on ciliates belonging to different taxonomic groups. Results suggest that, as already assessed for many macro-organisms like plants and metazoans, ciliated protists harbor distinct microbiomes. The applied approach detected new potential symbionts as well as new hosts for previously described ones, with relatively low time and cost effort and without culturing. When further developed, single-cell microbiomics for ciliates could be applied to a large number of studies aiming to unravel the evolutionary and ecological meaning of these symbiotic systems.


Assuntos
Bactérias/isolamento & purificação , Cilióforos/microbiologia , Metagenômica/métodos , Microbiota , Bactérias/classificação , Bactérias/genética , Fenômenos Fisiológicos Bacterianos , Evolução Biológica , Cilióforos/genética , Cilióforos/isolamento & purificação , Cilióforos/fisiologia , Ecossistema , Filogenia , Projetos Piloto , Análise de Sequência de DNA , Simbiose
17.
Eur J Protistol ; 67: 59-70, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30453233

RESUMO

We estimated the consumption of planktonic ciliates by fish larvae in the Väinameri Sea (a shallow semi-enclosed bay of the Baltic Sea) and Lake Võrtsjärv (a shallow and eutrophic lake). Our primary hypothesis was that planktonic ciliates constitute a substantial component of the diet of fish larvae in both environments. We also assumed that the contribution of ciliates to larval nutrition is bigger in lacustrine than in marine environment because ciliates are usually more abundant in lakes. The nutrition of field collected larval fish was determined by gut content analysis using epifluorescence microscopy. Our study revealed that ciliates occurred in the alimentary tracts of all fish species examined. We discovered that the consumption of ciliates by first-feeding fish larvae contributed approximately 40 and 60% of their total consumed carbon in the Väinameri and in Võrtsjärv, respectively. Ciliates represent essentially important food for fish larvae and sufficient protozoan food may enhance larval growth in the beginning of the exogenous feeding and shorten the most vulnerable period in larval stage before shifting to larger prey.


Assuntos
Baías , Cilióforos/fisiologia , Cadeia Alimentar , Lagos , Animais , Peixes/metabolismo , Conteúdo Gastrointestinal
18.
Zoolog Sci ; 35(6): 514-520, 2018 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-30520356

RESUMO

Although epibiont ciliates make up a significant part of the biomass in aquatic ecosystems and may cause perceptible alterations in the population dynamics of their hosts, studies on the extrinsic and intrinsic factors that control the abundance of these microorganisms are scarce in literature. In the present study, we investigated the colonization site and intensity of rhabdostylid epibiont upon chironomid larvae and assessed the influence of organic pollution and chironomid communities on the prevalence and abundance of epibiont ciliates at five sampling stations (two in rural areas and three in urban areas) along a neotropical urban stream over a period of 12 months. Among the 24 genera of chironomids found and the 31,976 larvae analyzed, 96.12% belonged to the Chironomus genus, of which 16.95% (5212) were colonized by Rhabdostyla aff. chironomi. The infestation intensity varied from one to 67 individuals per host with an average intensity of 4.86 (± 33.45). Ciliates were only found colonizing the chironomids' ventral tubules. The high number of chironomid larvae, high host- and site-specificity, low infestation intensity, and absence of apparent structural damage to hosts evidence an intimate relationship between epibiont and basibiont as well as a possibly long coevolutionary history. Both prevalence and abundance of epibiont ciliates were correlated to the pollution rate of the studied stream. There was an alteration in the composition and structure of the chironomid community along the sampling stations. Numeric dominance of Chironomus-tolerant chironomids and its direct correlation to infestation prevalence and to ciliates abundance highlights the predilection of both peritrich ciliates and Chironomus larvae for organically-enriched environments.


Assuntos
Chironomidae/fisiologia , Cilióforos/fisiologia , Animais , Brasil , Chironomidae/classificação , Água Doce , Especificidade de Hospedeiro , Larva/fisiologia , Poluentes Químicos da Água
19.
Proc Natl Acad Sci U S A ; 115(47): 11988-11993, 2018 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-30397109

RESUMO

Limited dispersal is classically considered as a prerequisite for ecological specialization to evolve, such that generalists are expected to show greater dispersal propensity compared with specialists. However, when individuals choose habitats that maximize their performance instead of dispersing randomly, theory predicts dispersal with habitat choice to evolve in specialists, while generalists should disperse more randomly. We tested whether habitat choice is associated with thermal niche specialization using microcosms of the ciliate Tetrahymena thermophila, a species that performs active dispersal. We found that thermal specialists preferred optimal habitats as predicted by theory, a link that should make specialists more likely to track suitable conditions under environmental changes than expected under the random dispersal assumption. Surprisingly, generalists also performed habitat choice but with a preference for suboptimal habitats. Since this result challenges current theory, we developed a metapopulation model to understand under which circumstances such a preference for suboptimal habitats should evolve. We showed that competition between generalists and specialists may favor a preference for niche margins in generalists under environmental variability. Our results demonstrate that the behavioral dimension of dispersal-here, habitat choice-fundamentally alters our predictions of how dispersal evolve with niche specialization, making dispersal behaviors crucial for ecological forecasting facing environmental changes.


Assuntos
Biota/fisiologia , Comportamento Competitivo/fisiologia , Tetrahymena thermophila/fisiologia , Animais , Evolução Biológica , Cilióforos/fisiologia , Ecossistema , Especialização , Especificidade da Espécie , Temperatura Ambiente , Territorialidade
20.
Curr Biol ; 28(20): R1180-R1184, 2018 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-30352182

RESUMO

Although we often think of cells as small, simple building blocks of life, in fact they are highly complex and can perform a startling variety of functions. In our bodies, cells are programmed by complex differentiation pathways and are capable of responding to a bewildering range of chemical and physical signals. Free-living single-celled organisms, such as bacteria or protists, have to cope with varying environments, locate prey and potential mates, and escape from predators - all of the same tasks that a free-living animal is faced with. When animals face complex behavioral challenges, they rely on their cognitive abilities - the ability to learn from experience, to analyse a situation and choose an appropriate course of action. This ability is essential for survival and should, in principle, be a ubiquitous feature of all living things regardless of the complexity of the organism.


Assuntos
Cilióforos/fisiologia , Physarum/fisiologia , Células , Habituação Psicofisiológica , Aprendizagem
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