Base de dados : MEDLINE
Pesquisa : B01.050.150.900.493.559 [Categoria DeCS]
Referências encontradas : 2321 [refinar]
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  1 / 2321 MEDLINE  
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[PMID]:29206846
[Au] Autor:Zuo Y; Xie W; Pang Y; Li T; Li Q; Li Y
[Ad] Endereço:School of Life Science, Liaoning Normal University, Dalian, China.
[Ti] Título:Bacterial community composition in the gut content of Lampetra japonica revealed by 16S rRNA gene pyrosequencing.
[So] Source:PLoS One;12(12):e0188919, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The composition of the bacterial communities in the hindgut contents of Lampetrs japonica was surveyed by Illumina MiSeq of the 16S rRNA gene. An average of 32385 optimized reads was obtained from three samples. The rarefaction curve based on the operational taxonomic units tended to approach the asymptote. The rank abundance curve representing the species richness and evenness was calculated. The composition of microbe in six classification levels was also analyzed. Top 20 members in genera level were displayed as the classification tree. The abundance of microorganisms in different individuals was displayed as the pie charts at the branch nodes in the classification tree. The differences of top 50 genera in abundance between individuals of lamprey are displayed as a heatmap. The pairwise comparison of bacterial taxa abundance revealed that there are no significant differences of gut microbiota between three individuals of lamprey at a given rarefied depth. Also, the gut microbiota derived from L. japonica displays little similarity with other aquatic organism of Vertebrata after UPGMA analysis. The metabolic function of the bacterial communities was predicted through KEGG analysis. This study represents the first analysis of the bacterial community composition in the gut content of L. japonica. The investigation of the gut microbiota associated with L. japonica will broaden our understanding of this unique organism.
[Mh] Termos MeSH primário: Bactérias/isolamento & purificação
Intestinos/microbiologia
Lampreias/microbiologia
RNA Ribossômico 16S/genética
[Mh] Termos MeSH secundário: Animais
Bactérias/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (RNA, Ribosomal, 16S)
[Em] Mês de entrada:1712
[Cu] Atualização por classe:171229
[Lr] Data última revisão:
171229
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171206
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0188919


  2 / 2321 MEDLINE  
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[PMID]:27771341
[Au] Autor:Chen L; Wu F; Yuan S; Feng B
[Ad] Endereço:Guangdong Province Key Laboratory for Medical Molecular Diagnostics, China-America Cancer Research Institute, Dongguan Scientific Research Center, Guangdong Medical University, Dongguan 523808, China. Electronic address: chenliyong09@163.com.
[Ti] Título:Identification and characteristic of three members of the C1q/TNF-related proteins (CTRPs) superfamily in Eudontomyzon morii.
[So] Source:Fish Shellfish Immunol;59:233-240, 2016 Dec.
[Is] ISSN:1095-9947
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:C1q is the target recognition protein of the classical complement pathway and a major connecting link between innate and acquired immunity. C1q and the multifunctional tumor necrosis factor (TNF) ligand family is of similar crystal structures, are designated the C1q/TNF-related proteins (CTRPs) superfamily. They are involved in processes as diverse as host defense, inflammation, apoptosis, autoimmunity, cell differentiation, organogenesis, hibernation and insulinresistant obesity. In this study, three members of the CTRPs superfamily were isolated and characterized in Yalu River lampreys (Eudontomyzon morii), and are respectively named LaC1qC, LaCTRP1, LaCTRP9. The full-length cDNAs of C1qC-like (LaC1qAL), CTRP1-like (LaCTRP1), and CTRP9-like (LaCTRP9) consist of 723, 762 and 825 bp of nucleotide sequence encoding polypeptides of 241, 254 and 275 amino acids, respectively. All-three proteins share three common domains: a signal peptide at the N terminus, a collagenous domain (characteristic Gly-X-Y repeats), and a C-terminal globular domain. In addition, the higher expression level of the three proteins in heart by RT-PCR and real-time PCR tissue profiling implied that they might involve in immune response or injury repair of the heart in lamprey.
[Mh] Termos MeSH primário: Proteínas de Peixes/genética
Imunidade Inata
Peptídeos e Proteínas de Sinalização Intracelular/genética
Lampreias/genética
Lampreias/imunologia
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Animais
Clonagem Molecular
DNA Complementar/genética
DNA Complementar/metabolismo
Proteínas de Peixes/química
Proteínas de Peixes/metabolismo
Peptídeos e Proteínas de Sinalização Intracelular/metabolismo
Lampreias/metabolismo
Especificidade de Órgãos
Filogenia
RNA Mensageiro/genética
RNA Mensageiro/metabolismo
Alinhamento de Sequência/veterinária
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Complementary); 0 (Fish Proteins); 0 (Intracellular Signaling Peptides and Proteins); 0 (RNA, Messenger)
[Em] Mês de entrada:1703
[Cu] Atualização por classe:171203
[Lr] Data última revisão:
171203
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161025
[St] Status:MEDLINE


  3 / 2321 MEDLINE  
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[PMID]:28924005
[Au] Autor:Ryczko D; Grätsch S; Schläger L; Keuyalian A; Boukhatem Z; Garcia C; Auclair F; Büschges A; Dubuc R
[Ad] Endereço:Groupe de Recherche sur le Système Nerveux Central, Département de Neurosciences, Université de Montréal, Montréal, Québec H3C 3J7, Canada.
[Ti] Título:Nigral Glutamatergic Neurons Control the Speed of Locomotion.
[So] Source:J Neurosci;37(40):9759-9770, 2017 Oct 04.
[Is] ISSN:1529-2401
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The mesencephalic locomotor region (MLR) plays a crucial role in locomotor control. In vertebrates, stimulation of the MLR at increasing intensities elicits locomotion of growing speed. This effect has been presumed to result from higher brain inputs activating the MLR like a dimmer switch. Here, we show in lampreys ( ) of either sex that incremental stimulation of a region homologous to the mammalian substantia nigra pars compacta (SNc) evokes increasing activation of MLR cells with a graded increase in the frequency of locomotor movements. Neurons co-storing glutamate and dopamine were found to project from the primal SNc to the MLR. Blockade of glutamatergic transmission largely diminished MLR cell responses and locomotion. Local blockade of D receptors in the MLR decreased locomotor frequency, but did not disrupt the SNc-evoked graded control of locomotion. Our findings revealed the presence of a glutamatergic input to the MLR originating from the primal SNc that evokes graded locomotor movements. The mesencephalic locomotor region (MLR) plays a crucial role in the control of locomotion. It projects downward to reticulospinal neurons that in turn activate the spinal locomotor networks. Increasing the intensity of MLR stimulation produces a growing activation of reticulospinal cells and a progressive increase in the speed of locomotor movements. Since the discovery of the MLR some 50 years ago, it has been presumed that higher brain regions activate the MLR in a graded fashion, but this has not been confirmed yet. Here, using a combination of techniques from cell to behavior, we provide evidence of a new glutamatergic pathway activating the MLR in a graded fashion, and consequently evoking a progressive increase in locomotor output.
[Mh] Termos MeSH primário: Ácido Glutâmico/fisiologia
Locomoção/fisiologia
Neurônios/fisiologia
Substância Negra/fisiologia
Natação/fisiologia
[Mh] Termos MeSH secundário: Potenciais de Ação/fisiologia
Animais
Lampreias
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
3KX376GY7L (Glutamic Acid)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171012
[Lr] Data última revisão:
171012
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170920
[St] Status:MEDLINE
[do] DOI:10.1523/JNEUROSCI.1810-17.2017


  4 / 2321 MEDLINE  
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[PMID]:28716949
[Au] Autor:Quinlan EM; King JJ; Amemiya CT; Hsu E; Larijani M
[Ad] Endereço:Department of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada.
[Ti] Título:Biochemical Regulatory Features of Activation-Induced Cytidine Deaminase Remain Conserved from Lampreys to Humans.
[So] Source:Mol Cell Biol;37(20), 2017 Oct 15.
[Is] ISSN:1098-5549
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Activation-induced cytidine deaminase (AID) is a genome-mutating enzyme that initiates class switch recombination and somatic hypermutation of antibodies in jawed vertebrates. We previously described the biochemical properties of human AID and found that it is an unusual enzyme in that it exhibits binding affinities for its substrate DNA and catalytic rates several orders of magnitude higher and lower, respectively, than a typical enzyme. Recently, we solved the functional structure of AID and demonstrated that these properties are due to nonspecific DNA binding on its surface, along with a catalytic pocket that predominantly assumes a closed conformation. Here we investigated the biochemical properties of AID from a sea lamprey, nurse shark, tetraodon, and coelacanth: representative species chosen because their lineages diverged at the earliest critical junctures in evolution of adaptive immunity. We found that these earliest-diverged AID orthologs are active cytidine deaminases that exhibit unique substrate specificities and thermosensitivities. Significant amino acid sequence divergence among these AID orthologs is predicted to manifest as notable structural differences. However, despite major differences in sequence specificities, thermosensitivities, and structural features, all orthologs share the unusually high DNA binding affinities and low catalytic rates. This absolute conservation is evidence for biological significance of these unique biochemical properties.
[Mh] Termos MeSH primário: Citidina Desaminase/metabolismo
Switching de Imunoglobulina/imunologia
Lampreias/metabolismo
Especificidade por Substrato/imunologia
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Animais
DNA/metabolismo
Seres Humanos
Mutação/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
9007-49-2 (DNA); EC 3.5.4.5 (Cytidine Deaminase)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171020
[Lr] Data última revisão:
171020
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170719
[St] Status:MEDLINE


  5 / 2321 MEDLINE  
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[PMID]:28669817
[Au] Autor:Timoshevskiy VA; Lampman RT; Hess JE; Porter LL; Smith JJ
[Ad] Endereço:University of Kentucky, Department of Biology, Lexington, KY 40506, USA.
[Ti] Título:Deep ancestry of programmed genome rearrangement in lampreys.
[So] Source:Dev Biol;429(1):31-34, 2017 09 01.
[Is] ISSN:1095-564X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:In most multicellular organisms, the structure and content of the genome is rigorously maintained over the course of development. However some species have evolved genome biologies that permit, or require, developmentally regulated changes in the physical structure and content of the genome (programmed genome rearrangement: PGR). Relatively few vertebrates are known to undergo PGR, although all agnathans surveyed to date (several hagfish and one lamprey: Petromyzon marinus) show evidence of large scale PGR. To further resolve the ancestry of PGR within vertebrates, we developed probes that allow simultaneous tracking of nearly all sequences eliminated by PGR in P. marinus and a second lamprey species (Entosphenus tridentatus). These comparative analyses reveal conserved subcellular structures (lagging chromatin and micronuclei) associated with PGR and provide the first comparative embryological evidence in support of the idea that PGR represents an ancient and evolutionarily stable strategy for regulating inherent developmental/genetic conflicts between germline and soma.
[Mh] Termos MeSH primário: Rearranjo Gênico/genética
Genoma
Lampreias/genética
Filogenia
[Mh] Termos MeSH secundário: Animais
DNA/metabolismo
Células Germinativas/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL
[Nm] Nome de substância:
9007-49-2 (DNA)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171111
[Lr] Data última revisão:
171111
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170704
[St] Status:MEDLINE


  6 / 2321 MEDLINE  
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[PMID]:28624345
[Au] Autor:York JR; Yuan T; Zehnder K; McCauley DW
[Ad] Endereço:Department of Biology, University of Oklahoma, 730 Van Vleet Oval, Norman, OK 73019, USA.
[Ti] Título:Lamprey neural crest migration is Snail-dependent and occurs without a differential shift in cadherin expression.
[So] Source:Dev Biol;428(1):176-187, 2017 08 01.
[Is] ISSN:1095-564X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The acquisition of neural crest cells was a key step in the origin of the vertebrate body plan. An outstanding question is how neural crest cells acquired their ability to undergo an epithelial-mesenchymal transition (EMT) and migrate extensively throughout the vertebrate embryo. We tested if differential regulation of classical cadherins-a highly conserved feature of neural crest EMT and migration in jawed vertebrates-mediates these cellular behaviors in lamprey, a basal jawless vertebrate. Lamprey has single copies of the type I and type II classical cadherins (CadIA and CadIIA). CadIIA is expressed in premigratory neural crest, and requires the transcription factor Snail for proper expression, yet CadIA is never expressed in the neural tube during neural crest development, suggesting that differential regulation of classical cadherin expression is not required to initiate neural crest migration in basal vertebrates. We hypothesize that neural crest cells evolved by retention of regulatory programs linking distinct mesenchymal and multipotency properties, and emigrated from the neural tube without differentially regulating type I/type II cadherins. Our results point to the coupling of mesenchymal state and multipotency as a key event facilitating the origin of migratory neural crest cells.
[Mh] Termos MeSH primário: Caderinas/metabolismo
Movimento Celular/fisiologia
Lampreias/embriologia
Crista Neural/embriologia
Fatores de Transcrição da Família Snail/metabolismo
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Animais
Caderinas/genética
Diferenciação Celular/fisiologia
Transição Epitelial-Mesenquimal/fisiologia
Regulação da Expressão Gênica no Desenvolvimento
Crista Neural/citologia
Tubo Neural/metabolismo
Alinhamento de Sequência
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Cadherins); 0 (Snail Family Transcription Factors)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171111
[Lr] Data última revisão:
171111
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170619
[St] Status:MEDLINE


  7 / 2321 MEDLINE  
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[PMID]:28610230
[Au] Autor:Tutman P; Freyhof J; Dulcic J; Glamuzina B; Geiger M
[Ad] Endereço:Institute of Oceanography and Fisheries, Setaliste Ivana Mestrovica 63, 21000 Split, Croatia.. tutman@izor.hr.
[Ti] Título:Lampetra soljani, a new brook lamprey from the southern Adriatic Sea basin (Petromyzontiformes: Petromyzontidae).
[So] Source:Zootaxa;4273(4):531-548, 2017 Jun 07.
[Is] ISSN:1175-5334
[Cp] País de publicação:New Zealand
[La] Idioma:eng
[Ab] Resumo:Lampetra soljani, new species, is described from the lower Neretva River in the Adriatic Sea basin. Previously it was identified as L. zanandreai. Based on morphological similarity and mitochondrial genetic data, it is related to L. lanceolata and L. ninae from the Black Sea basin. Lampetra soljani is distinguished from all other species of Lampetra by having a marmorate flank pattern in live, fully grown ammocoetes, and in some adults (vs. plain colour pattern). Lampetra soljani is distinguished from other Lampetra species by having three velar tentacles, 54-57 trunk myomeres between the last branchial opening and the anus, no posterial teeth and a bicuspid middle endolateral tooth. Lampetra soljani is also well distinguished by COI barcode data from its congeners. The new species is widespread in the Neretva River drainage and lampreys from Lake Skadar basin are likely to belong to this species also.
[Mh] Termos MeSH primário: Lampreias
[Mh] Termos MeSH secundário: Animais
Mar Negro
Genes Mitocondriais
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170809
[Lr] Data última revisão:
170809
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170615
[St] Status:MEDLINE
[do] DOI:10.11646/zootaxa.4273.4.4


  8 / 2321 MEDLINE  
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[PMID]:28214856
[Au] Autor:Salas CA; Yopak KE; Lisney TJ; Potter IC; Collin SP
[Ad] Endereço:School of Animal Biology, The University of Western Australia, Crawley, WA, Australia.
[Ti] Título:The Central Nervous System of Jawless Vertebrates: Encephalization in Lampreys and Hagfishes.
[So] Source:Brain Behav Evol;89(1):33-47, 2017.
[Is] ISSN:1421-9743
[Cp] País de publicação:Switzerland
[La] Idioma:eng
[Ab] Resumo:Lampreys and hagfishes are the sole surviving representatives of the early agnathan (jawless) stage in vertebrate evolution, which has previously been regarded as the least encephalized group of all vertebrates. Very little is known, however, about the extent of interspecific variation in relative brain size in these fishes, as previous studies have focused on only a few species, even though lampreys exhibit a variety of life history traits. While some species are parasitic as adults, with varying feeding behaviors, others (nonparasitic species) do not feed after completing their macrophagous freshwater larval phase. In addition, some parasitic species remain in freshwater, while others undergo an anadromous migration. On the basis of data for postmetamorphic individuals representing approximately 40% of all lamprey species, with representatives from each of the three families, the aforementioned differences in life history traits are reflected in variations in relative brain size. Across all lampreys, brain mass increases with body mass with a scaling factor or slope (α) of 0.35, which is less than those calculated for different groups of gnathostomatous (jawed) vertebrates (α = 0.43-0.62). When parasitic and nonparasitic species are analyzed separately, with phylogeny taken into account, the scaling factors of both groups (parasitic α = 0.43, nonparasitic α = 0.45) approach those of gnathostomes. The relative brain size in fully grown adults of parasitic species is, however, less than that of the adults of nonparasitic species, paralleling differences between fully grown adults and recently metamorphosed individuals of anadromous species. The average degree of encephalization is found in anadromous parasitic lampreys and might thus represent the ancestral condition for extant lampreys. These results suggest that the degree of encephalization in lampreys varies according to both life history traits and phylogenetic relationships.
[Mh] Termos MeSH primário: Evolução Biológica
Encéfalo/anatomia & histologia
Comportamento Alimentar/fisiologia
Feiticeiras (Peixe)
Lampreias
Filogenia
[Mh] Termos MeSH secundário: Animais
Tamanho Corporal
Feiticeiras (Peixe)/anatomia & histologia
Feiticeiras (Peixe)/fisiologia
Lampreias/anatomia & histologia
Lampreias/fisiologia
Tamanho do Órgão
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170719
[Lr] Data última revisão:
170719
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170220
[St] Status:MEDLINE
[do] DOI:10.1159/000455183


  9 / 2321 MEDLINE  
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[PMID]:28163253
[Au] Autor:Agalakova NI; Ivanova TI; Gusev GP; Nazarenkova AV; Sufiyeva DA
[Ad] Endereço:Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, M. Thorez av. 44, Sankt-Petersburg, 194223, Russia. Electronic address: nagalak@mail.ru.
[Ti] Título:Apoptotic death in erythrocytes of lamprey Lampetra fluviatilis induced by ionomycin and tert-butyl hydroperoxide.
[So] Source:Comp Biochem Physiol C Toxicol Pharmacol;194:48-60, 2017 Apr.
[Is] ISSN:1532-0456
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The work examined the effects of Ca overload and oxidative damage on erythrocytes of river lamprey Lampetra fluvialtilis. The cells were incubated for 3h with 0.1-5µM Ca ionophore ionomycin in combination with 2.5mM Ca and 10-100µM pro-oxidant agent tert-butyl hydroperoxide (tBHP). The sensitivity of lamprey RBCs to studied compounds was evaluated by the kinetics of their death. Both toxicants induced dose- and time dependent phosphatidylserine (PS) externalization (annexin V-FITC labeling) and loss of membrane integrity (propidium iodide uptake). Highest doses of ionomycin (1-2µM) increased the number of PS-exposed erythrocytes to 7-9% within 3h, while 100µM tBHP produced up to 50% of annexin V-FITC-positive cells. Caspase inhibitor Boc-D-FMK (50µM), calpain inhibitor PD150606 (10µM) and broad protease inhibitor leupeptin (200µM) did not prevent ionomycin-induced PS externalization, whereas tBHP-triggered apoptosis was blunted by Boc-D-FMK. tBHP-dependent death of lamprey erythrocytes was accompanied by the decrease in relative cell size, loss of cell viability, activation of caspases 9 and 3/7, and loss of mitochondrial membrane potential, but all these processes were partially attenuated by Boc-D-FMK. None of examined death-associated events were observed in ionomycin-treated erythrocytes except activation of caspase-9. Incubation with ionomycin did not alter intracellular K and Na content, while exposure to tBHP resulted in 80% loss of K and 2.8-fold accumulation of Na . Thus, lamprey erythrocytes appear to be more susceptible to oxidative damage. Ca overload does not activate the cytosolic death pathways in these cells.
[Mh] Termos MeSH primário: Apoptose/efeitos dos fármacos
Ionóforos de Cálcio/toxicidade
Eritrócitos/efeitos dos fármacos
Ionomicina/toxicidade
Oxidantes/toxicidade
Poluentes Químicos da Água/toxicidade
terc-Butil Hidroperóxido/toxicidade
[Mh] Termos MeSH secundário: Animais
Biomarcadores/sangue
Biomarcadores/metabolismo
Tamanho Celular
Sobrevivência Celular/efeitos dos fármacos
Eritrócitos/citologia
Eritrócitos/metabolismo
Feminino
Cinética
Lampreias
Masculino
Potencial da Membrana Mitocondrial/efeitos dos fármacos
Estresse Oxidativo/efeitos dos fármacos
Rios
Federação Russa
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Biomarkers); 0 (Calcium Ionophores); 0 (Oxidants); 0 (Water Pollutants, Chemical); 56092-81-0 (Ionomycin); 955VYL842B (tert-Butylhydroperoxide)
[Em] Mês de entrada:1703
[Cu] Atualização por classe:170310
[Lr] Data última revisão:
170310
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170207
[St] Status:MEDLINE


  10 / 2321 MEDLINE  
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[PMID]:28108670
[Au] Autor:Warrington RE; Hart NS; Potter IC; Collin SP; Hemmi JM
[Ad] Endereço:School of Biological Sciences (M092), The University of Western Australia, Crawley, WA 6009, Australia rachaelwarrington@hotmail.com.
[Ti] Título:Retinal temporal resolution and contrast sensitivity in the parasitic lamprey and its non-parasitic derivative .
[So] Source:J Exp Biol;220(Pt 7):1245-1255, 2017 Apr 01.
[Is] ISSN:1477-9145
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Lampreys and hagfishes are the sole extant representatives of the early agnathan (jawless) vertebrates. We compared retinal function of fully metamorphosed, immature (which are about to commence parasitic feeding) with those of sexually mature individuals of its non-parasitic derivative We focused on elucidating the retinal adaptations to dim-light environments in these nocturnally active lampreys, using electroretinography to determine the temporal resolution (flicker fusion frequency, FFF) and temporal contrast sensitivity of enucleated eyecups at different temperatures and light intensities. FFF was significantly affected by temperature and light intensity. Critical flicker fusion frequency (cFFF, the highest FFF recorded) of and increased from 15.1 and 21.8 Hz at 9°C to 31.1 and 36.9 Hz at 24°C, respectively. Contrast sensitivity of both species increased by an order of magnitude between 9 and 24°C, but remained comparatively constant across all light intensities. Although FFF values for spp. are relatively low, retinal responses showed a particularly high contrast sensitivity of 625 in and 710 in at 24°C. This suggests selective pressures favour low temporal resolution and high contrast sensitivity in both species, thereby enhancing the capture of photons and increasing sensitivity in their light-limited environments. FFF indicated all retinal photoreceptors exhibit the same temporal response. Although the slow response kinetics (i.e. low FFF) and saturation of the response at bright light intensities characterise the photoreceptors of both species as rod-like, it is unusual for such a photoreceptor to be functional under scotopic and photopic conditions.
[Mh] Termos MeSH primário: Sensibilidades de Contraste
Lampreias/fisiologia
[Mh] Termos MeSH secundário: Animais
Feminino
Fusão Flicker
Luz
Retina/fisiologia
Visão Ocular
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170908
[Lr] Data última revisão:
170908
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170122
[St] Status:MEDLINE
[do] DOI:10.1242/jeb.150383



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