排序方式: 共有59条查询结果,搜索用时 15 毫秒
41.
Ghedin E Wang S Spiro D Caler E Zhao Q Crabtree J Allen JE Delcher AL Guiliano DB Miranda-Saavedra D Angiuoli SV Creasy T Amedeo P Haas B El-Sayed NM Wortman JR Feldblyum T Tallon L Schatz M Shumway M Koo H Salzberg SL Schobel S Pertea M Pop M White O Barton GJ Carlow CK Crawford MJ Daub J Dimmic MW Estes CF Foster JM Ganatra M Gregory WF Johnson NM Jin J Komuniecki R Korf I Kumar S Laney S Li BW Li W Lindblom TH Lustigman S Ma D Maina CV Martin DM McCarter JP McReynolds L Mitreva M Nutman TB 《Science (New York, N.Y.)》2007,317(5845):1756-1760
Parasitic nematodes that cause elephantiasis and river blindness threaten hundreds of millions of people in the developing world. We have sequenced the approximately 90 megabase (Mb) genome of the human filarial parasite Brugia malayi and predict approximately 11,500 protein coding genes in 71 Mb of robustly assembled sequence. Comparative analysis with the free-living, model nematode Caenorhabditis elegans revealed that, despite these genes having maintained little conservation of local synteny during approximately 350 million years of evolution, they largely remain in linkage on chromosomal units. More than 100 conserved operons were identified. Analysis of the predicted proteome provides evidence for adaptations of B. malayi to niches in its human and vector hosts and insights into the molecular basis of a mutualistic relationship with its Wolbachia endosymbiont. These findings offer a foundation for rational drug design. 相似文献
42.
Berriman M Ghedin E Hertz-Fowler C Blandin G Renauld H Bartholomeu DC Lennard NJ Caler E Hamlin NE Haas B Böhme U Hannick L Aslett MA Shallom J Marcello L Hou L Wickstead B Alsmark UC Arrowsmith C Atkin RJ Barron AJ Bringaud F Brooks K Carrington M Cherevach I Chillingworth TJ Churcher C Clark LN Corton CH Cronin A Davies RM Doggett J Djikeng A Feldblyum T Field MC Fraser A Goodhead I Hance Z Harper D Harris BR Hauser H Hostetler J Ivens A Jagels K Johnson D Johnson J Jones K Kerhornou AX Koo H 《Science (New York, N.Y.)》2005,309(5733):416-422
African trypanosomes cause human sleeping sickness and livestock trypanosomiasis in sub-Saharan Africa. We present the sequence and analysis of the 11 megabase-sized chromosomes of Trypanosoma brucei. The 26-megabase genome contains 9068 predicted genes, including approximately 900 pseudogenes and approximately 1700 T. brucei-specific genes. Large subtelomeric arrays contain an archive of 806 variant surface glycoprotein (VSG) genes used by the parasite to evade the mammalian immune system. Most VSG genes are pseudogenes, which may be used to generate expressed mosaic genes by ectopic recombination. Comparisons of the cytoskeleton and endocytic trafficking systems with those of humans and other eukaryotic organisms reveal major differences. A comparison of metabolic pathways encoded by the genomes of T. brucei, T. cruzi, and Leishmania major reveals the least overall metabolic capability in T. brucei and the greatest in L. major. Horizontal transfer of genes of bacterial origin has contributed to some of the metabolic differences in these parasites, and a number of novel potential drug targets have been identified. 相似文献
43.
Longeon A Copp BR Quévrain E Roué M Kientz B Cresteil T Petek S Debitus C Bourguet-Kondracki ML 《Marine drugs》2011,9(5):879-888
Indole derivatives including bromoindoles have been isolated from the South Pacific marine sponges Rhopaloeides odorabile and Hyrtios sp. Their structures were established through analysis of mass spectra and 1D and 2D NMR spectroscopic data. Their potential inhibitory phospholipase A2 (PLA2), antioxidant and cytotoxic activities were evaluated. The new derivative 5,6-dibromo-l-hypaphorine (9) isolated from Hyrtios sp. revealed a weak bee venom PLA2 inhibition (IC50 0.2 mM) and a significant antioxidant activity with an Oxygen Radical Absorbance Capacity (ORAC) value of 0.22. The sesquiterpene aureol (4), also isolated from Hyrtios sp., showed the most potent antioxidant activity with an ORAC value of 0.29. 相似文献
44.
El-Sayed NM Myler PJ Bartholomeu DC Nilsson D Aggarwal G Tran AN Ghedin E Worthey EA Delcher AL Blandin G Westenberger SJ Caler E Cerqueira GC Branche C Haas B Anupama A Arner E Aslund L Attipoe P Bontempi E Bringaud F Burton P Cadag E Campbell DA Carrington M Crabtree J Darban H da Silveira JF de Jong P Edwards K Englund PT Fazelina G Feldblyum T Ferella M Frasch AC Gull K Horn D Hou L Huang Y Kindlund E Klingbeil M Kluge S Koo H Lacerda D Levin MJ Lorenzi H Louie T Machado CR McCulloch R 《Science (New York, N.Y.)》2005,309(5733):409-415
Whole-genome sequencing of the protozoan pathogen Trypanosoma cruzi revealed that the diploid genome contains a predicted 22,570 proteins encoded by genes, of which 12,570 represent allelic pairs. Over 50% of the genome consists of repeated sequences, such as retrotransposons and genes for large families of surface molecules, which include trans-sialidases, mucins, gp63s, and a large novel family (>1300 copies) of mucin-associated surface protein (MASP) genes. Analyses of the T. cruzi, T. brucei, and Leishmania major (Tritryp) genomes imply differences from other eukaryotes in DNA repair and initiation of replication and reflect their unusual mitochondrial DNA. Although the Tritryp lack several classes of signaling molecules, their kinomes contain a large and diverse set of protein kinases and phosphatases; their size and diversity imply previously unknown interactions and regulatory processes, which may be targets for intervention. 相似文献
45.
Fernandes I Rousset E Dufour P Sidi-Boumedine K Cupo A Thiéry R Duquesne V 《Veterinary microbiology》2009,134(3-4):300-304
Coxiella burnetii is an intracellular bacterium that causes a worldwide zoonosis, the Q fever. Currently, to diagnose the infection in ruminants, whole cell antigens-based ELISAs are used. In this study a heat shock protein, the HspB, was evaluated for its ability to be recognized by the goat immune system and its capacity to sign a stage of infection. The htpB gene of C. burnetii was cloned and sequenced. A high identity (>90%) was observed among the htpB genes of four ruminant strains tested. A recombinant protein was expressed in a prokaryotic expression system. The rHspB protein was used to determine the IgG reactivity by ELISA. Sera from experimentally and naturally infected goats were tested. The rHspB is recognized early during the infection course, at 18 days post-infection. Moreover, 80-90% of the animals tested were positive at 39-60dpi. In addition, animals presenting a reactivation of the infection displayed a higher reactivity, statistically significant (p<0.05), than that of the animals in latent infection. These findings suggest that the rHspB could be a good candidate for the development of an ELISA test making possible the detection of recent C. burnetii infection in goats as well as reactivation in those with latent infection. 相似文献
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47.
Elodie Portanier Jeremy Larroque Mathieu Garel Pascal Marchand Daniel Maillard Gilles Bourgoin Sébastien Devillard 《Landscape Ecology》2018,33(7):1069-1085
Context
In natural populations, gene flow often represents a key factor in determining and maintaining genetic diversity. In a worldwide context of habitat fragmentation, assessing the relative contribution of landscape features to gene flow thus appears crucial for sustainable management of species.Objective
We addressed this issue in Mediterranean mouflon (Ovis gmelini musimon?×?Ovis sp.) by combining previous knowledge on behavioral ecology with landscape genetics. We also assessed how sex-specific behavioral differences translated in term of functional connectivity in both sexes.Methods
We relied on 239 individuals genotyped at 16 microsatellite markers. We applied a model optimization approach in a causal modeling framework of landscape genetics to test for the effects on gene flow of habitat types and linear landscape features previously identified as important for movements and habitat selection in both sexes. Five resistance values were alternately assigned to these landscape characteristics leading to a comprehensive set of resistance surfaces.Results
Isolation by resistance shaped female gene flow, supporting the central role of linear landscape features as behavioral barriers for animal movements. Conversely, no isolation by resistance was detected in males. Although a lack of statistical power cannot be discarded to explain this result, it tended to confirm that males are less influenced by landscape structures during the mating period.Conclusions
Combining previous knowledge on behavioral ecology with results from landscape genetics was decisive in assessing functional landscape connectivity in both sexes. These results highlighted the need to perform sex-specific studies for management and conservation of dimorphic species.48.
Dunning Hotopp JC Clark ME Oliveira DC Foster JM Fischer P Muñoz Torres MC Giebel JD Kumar N Ishmael N Wang S Ingram J Nene RV Shepard J Tomkins J Richards S Spiro DJ Ghedin E Slatko BE Tettelin H Werren JH 《Science (New York, N.Y.)》2007,317(5845):1753-1756
Although common among bacteria, lateral gene transfer-the movement of genes between distantly related organisms-is thought to occur only rarely between bacteria and multicellular eukaryotes. However, the presence of endosymbionts, such as Wolbachia pipientis, within some eukaryotic germlines may facilitate bacterial gene transfers to eukaryotic host genomes. We therefore examined host genomes for evidence of gene transfer events from Wolbachia bacteria to their hosts. We found and confirmed transfers into the genomes of four insect and four nematode species that range from nearly the entire Wolbachia genome (>1 megabase) to short (<500 base pairs) insertions. Potential Wolbachia-to-host transfers were also detected computationally in three additional sequenced insect genomes. We also show that some of these inserted Wolbachia genes are transcribed within eukaryotic cells lacking endosymbionts. Therefore, heritable lateral gene transfer occurs into eukaryotic hosts from their prokaryote symbionts, potentially providing a mechanism for acquisition of new genes and functions. 相似文献
49.
Inger M Brunborg Caroline Fossum Bj?rn Lium Gunilla Blomqvist Elodie Merlot Anne J?rgensen Lena Eliasson-Selling Espen Rimstad Christine M Jonassen Per Wallgren 《Acta veterinaria Scandinavica》2010,52(1):22
Background
Despite that PMWS commonly affects pigs aged eight to sixteen weeks; most studies of PMWS have been conducted during the period before transfer to finishing herds. This study focused on PCV2 load and antibody dynamics in finishing herds with different PMWS status.Methods
Sequentially collected blood samples from 40 pigs in each of two Swedish (A and B) and one Norwegian (C) finishing herds were analysed for serum PCV2-load and -antibodies and saliva cortisol. The two Swedish herds differed in PMWS status, despite receiving animals from the same sow pool (multi-site production). However, the PMWS-deemed herd (A) had previously also received pigs from the spot market. ResultsThe initial serum PCV2 load was similar in the two Swedish herds. In herd A, it peaked after two weeks in the finishing herd and a high number of the pigs had serum PCV2 levels above 107 per ml. The antibody titres increased continually with exception for the pigs that developed PMWS, that had initially low and then declining antibody levels. Pigs in the healthy herd B also expressed high titres of antibodies to PCV2 on arrival but remained at that level throughout the study whereas the viral load steadily decreased. No PCV2 antibodies and only low amounts of PCV2 DNA were detected in serum collected during the first five weeks in the PMWS-free herd C. Thereafter a peak in serum PCV2 load accompanied by an antibody response was recorded. PCV2 from the two Swedish herds grouped into genotype PCV2b whereas the Norwegian isolate grouped into PCV2a. Cortisol levels were lower in herd C than in herds A and B.Conclusions
The most obvious difference between the Swedish finishing herds and the Norwegian herd was the time of infection with PCV2 in relation to the time of allocation, as well as the genotype of PCV2. Clinical PMWS was preceded by low levels of serum antibodies and a high load of PCV2 but did not develop in all such animals. It is notable that herd A became affected by PMWS after errors in management routine, emphasising the importance of proper hygiene and general disease-preventing measures. 相似文献50.
Erin Nelson Laura Gómez Tovar Elodie Gueguen Sally Humphries Karen Landman Rita Schwentesius Rindermann 《Agriculture and Human Values》2016,33(2):373-388
Although it is the most widely accepted form of organic guarantee, third party certification can be inaccessible for small-scale producers and promotes a highly market-oriented vision of organics. By contrast, participatory guarantee systems (PGS) are based on principles of relationship-building, mutual learning, trust, context-specificity, local control, diversity, and collective action. This paper uses the case study of the Mexican Network of Local Organic Markets to explore how PGS can be used to support a more alternative vision of organics, grounded in the notion of food sovereignty. It presents some of the key challenges and opportunities associated with the approach, and highlights its potential to serve as a locally-based institution for collective action, thereby offering some structural support to alternative agri-food initiatives. 相似文献