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1.
Albert DG de Roos 《Biology direct》2007,2(1):7-17
Background
The timing of the origin of introns is of crucial importance for an understanding of early genome architecture. The Exon theory of genes proposed a role for introns in the formation of multi-exon proteins by exon shuffling and predicts the presence of conserved splice sites in ancient genes. In this study, large-scale analysis of potential conserved splice sites was performed using an intron-exon database (ExInt) derived from GenBank. 相似文献2.
Makarova OV Viktorova TV Ianbaeva DG Korytina GF Iakupova EV Karimova LK 《Genetika》2003,39(9):1268-1274
Genetic polymorphism of xenobiotic metabolizing enzymes responsible for individual susceptibility to different environmental factors was examined in a cohort of petrochemical workers occupationally exposed to adverse action of chemical compounds. Molecular genetic analysis of the 1462V mutation in exon 17 of the CYP1A gene demonstrated close similarity between the genotype and allele frequency distribution patterns in the industrial and control groups. No association between the CYP1A polymorphic alleles and genotypes and the duration of service and concomitant diseases was observed. The odds ratio of the disease development in the workers carrying heterozygous CYP1A1 mutant allele was 2.2. Analysis of the STM1 gene polymorphism demonstrated a decrease in the frequency of the homozygous deletion carriers in the workers compared to the control group. There were no substantial differences between the industrial and control groups with respect to the frequencies of rapid and slow acetylator genotypes revealed at the analysis of the NAT2 gene polymorphism. However, considering the concomitant diseases, in the corresponding industrial subgroup a clear trend towards lower frequency of rapid acetylators was demonstrated. In addition, the odds ratio of the disease development for the workers with slow acetylator phenotype was 1.7. 相似文献
3.
Sergey M Zuev Stephen F Kingsmore Damian DG Gessler 《Theoretical biology & medical modelling》2006,3(1):8-15
Background
Sepsis (bloodstream infection) is the leading cause of death in non-surgical intensive care units. It is diagnosed in 750,000 US patients per annum, and has high mortality. Current understanding of sepsis is predominately observational and correlational, with only a partial and incomplete understanding of the physiological dynamics underlying the syndrome. There exists a need for dynamical models of sepsis progression, based upon basic physiologic principles, which could eventually guide hourly treatment decisions. 相似文献4.
Johannes A Hofberger Beifei Zhou Haibao Tang Jonathan DG Jones M Eric Schranz 《BMC genomics》2014,15(1)
Background
Recent advances in DNA sequencing techniques resulted in more than forty sequenced plant genomes representing a diverse set of taxa of agricultural, energy, medicinal and ecological importance. However, gene family curation is often only inferred from DNA sequence homology and lacks insights into evolutionary processes contributing to gene family dynamics. In a comparative genomics framework, we integrated multiple lines of evidence provided by gene synteny, sequence homology and protein-based Hidden Markov Modelling to extract homologous super-clusters composed of multi-domain resistance (R)-proteins of the NB-LRR type (for NUCLEOTIDE BINDING/LEUCINE-RICH REPEATS), that are involved in plant innate immunity.Results
To assess the diversity of R-proteins within and between species, we screened twelve eudicot plant genomes including six major crops and found a total of 2,363 NB-LRR genes. Our curated R-proteins set shows a 50% average for tandem duplicates and a 22% fraction of gene copies retained from ancient polyploidy events (ohnologs). We provide evidence for strong positive selection and show significant differences in molecular evolution rates (Ka/Ks-ratio) among tandem- (mean = 1.59), ohnolog (mean = 1.36) and singleton (mean = 1.22) R-gene duplicates. To foster the process of gene-edited plant breeding, we report species-specific presence/absence of all 140 NB-LRR genes present in the model plant Arabidopsis and describe four distinct clusters of NB-LRR “gatekeeper” loci sharing syntenic orthologs across all analyzed genomes.Conclusion
By curating a near-complete set of multi-domain R-protein clusters in an eudicot-wide scale, our analysis offers significant insight into evolutionary dynamics underlying diversification of the plant innate immune system. Furthermore, our methods provide a blueprint for future efforts to identify and more rapidly clone functional NB-LRR genes from any plant species.Electronic supplementary material
The online version of this article (doi:10.1186/1471-2164-15-966) contains supplementary material, which is available to authorized users. 相似文献5.
Alison M Clargo Ashley R Hudson Welcome Ndlovu Rebecca J Wootton Louise A Cremin Victoria L O'Dowd Carla R Nowosad Dale O Starkie Sophie P Shaw Joanne E Compson Dominic P White Brendon MacKenzie James R Snowden Laura E Newnham Michael Wright Paul E Stephens Meryn R Griffiths Alastair DG Lawson Daniel J Lightwood 《MABS-AUSTIN》2014,6(1):143-159
6.
Human alveolar macrophage fibronectin: synthesis, secretion, and ultrastructural localization during gelatin-coated latex particle binding 总被引:14,自引:4,他引:10 下载免费PDF全文
Human pulmonary alveolar macrophages synthesized and secreted several characteristic high molecular weight proteins for at least 7 d in vitro. Immunoprecipitates of medium and cell lysates from metabolically labeled cultures with specific anti-human plasma fibronectin IgG contained one major labeled polypeptide of molecular weight 440,000 (unreduced) or 220,000 (reduced). An identical polypeptide in conditioned medium from radiolabeled macrophages bound specifically to gelatin-Sepharose, demonstrating that alveolar macrophages synthesized and secreted a molecule immunologically and functionally similar to fibronectin. Fibronectin was the major newly synthesized and secreted polypeptide of freshly harvested alveolar macrophages. Pulse-chase experiments revealed that newly synthesized fibronectin was rapidly secreted into medium, approximately 50 percent appearing by 1 h and 80 percent by 8 h. Immunoperoxidase staining using antifibronectin F(ab’)(2)-peroxidase conjugates revealed the majority of immunoreactive fibronectin to be intracellular, localized to endoplasmic reticulum and Golgi apparatus. No extracellular matrix fibronectin was visualized, and cell surface staining was rarely seen, usually appearing only at sites where cells were closely apposed and not at sites of macrophage-substrate attachment. Similar immunostaining of fibroblast cultures revealed cell surface-associated fibrillar fibronectin. Ultrastructural localization of fibronectin during binding and phagocytosis of gelatin-coated and plain latex particles revealed fibronectin only on gelatin-latex beads and at their cell binding sites. Neigher plain latex beads nor their cell membrane binding sites stained for fibronectin. These results demonstrate that fibronectin is a major product of human alveolar macrophages, is rapidly secreted, and is localized at cell membrane binding sites for gelatin-coated particles. In view of the known binding properties of fibronectin, it may serve as an endogenous opsonic factor promoting the binding of staphylococcus, denatured collagen, fibrin, or other macromolecules to macrophages in the lower respiratory tract. 相似文献
7.
Breakdown points of t-type regression estimators 总被引:5,自引:0,他引:5
8.
Viktorova TV Korytina GF Makarova OV Ianbaeva DG Iakupova EV Khusnutdinova EK 《Genetika》2003,39(6):855-857
Restriction fragment-length polymorphism of the gene coding for N-acetyltransferase 2 (NAT2) was typed in populations of the Volga-Ural region (Bashkirs, Tatars, Chuvashes, Udmurts, and Russians) as well as in patients with chronic obstructive pulmonary disease (COPD) and in healthy individuals. Rapid and slow acetylator phenotypes were determined based on the presence or absence of the KpnI, TaqI, and BamHI restriction endonuclease recognition sites. The proportion of slow acetylators in the populations examined varied from 40.00% in Bashkirs to 64.15% in Chuvashes with statistically significant difference between these two ethnic groups (chi 2 = 5.7; p = 0.02). Overall, in the Volga-Ural populations slow acetylators represented 56.25% of the subjects examined. This value was similar to those presented in other studies of Caucasoid populations. In the COPD patients a statistically significant decrease of the slow acetylator frequency to 48.28% compared to healthy individuals (62.18%) was observed (chi 2 = 4.60; p = 0.036). The data obtained suggest a possible association between the drug resistance in the COPD patients with the rapid acetylator phenotype, which can lead to the development of the chronic form of the disease. 相似文献
9.
Beneficial effect of fluorocarbon emulsion media on the function of neuromuscular preparations in vitro 下载免费PDF全文
The effects of liquid fluorocarbons as bathing media were determined by use of in vitro neuromuscular preparations. Rat hemidiaphragms were bathed in either oxygenated fluorocarbon (FC) emulsion or standard oxygenated Krebs solution. Contractile force in response to simple supramaximal nerve stimuli as well as to high frequency stimulation was greater, while twitch:tetanus ratio was smaller in FC emulsion. With such medium, post-tetanic potentiation of contraction was also more consistently observed. Indirectly stimulated diaphragms survived longer in FC emulsion. After cessation of oxygenation, oxygen tension (ρO(2)) of the medium declined more rapidly with Krebs than with FC emulsion; ρO(2) directly correlated with force of contraction. Similarly, in the chick biventer cervicis preparation, FC emulsion enhanced nerve-stimulated force of contraction; returning the preparation to standard Krebs solution reversed this phenomenon. Dose-resonse curves of muscle contraction in response to acetycholine and KCl administration were shifted upward during FC emulsion superfusion. Frequency of miniature endplate potentials was lower in FC emulsion than that observed in Krebs solution, measured from the same cell of the rat diaphragm. Resting membrane potentials were also greater in muscle cells sampled from FC emulsion-bathed preparations. These data suggest that FC emulsion is superior to standard Krebs solution as a bathing medium for in vitro neuromuscular preparations by virtue of the high solubility of oxygen in it. 相似文献
10.
Carla DB Fernandez Fernanda F Bellentani Glaura SA Fernandes Juliana E Perobelli Ana Paula A Favareto André F Nascimento Antonio C Cicogna Wilma DG Kempinas 《Reproductive biology and endocrinology : RB&E》2011,9(1):32