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991.
Hodgson KA Morris JL Feterl ML Govan BL Ketheesan N 《Microbes and infection / Institut Pasteur》2011,13(14-15):1177-1184
This study used a murine model of type 2 diabetes (BKS.Cg-Dock7(m) +/+Lepr(db)/J mice) to investigate the inflammatory and cellular mechanisms predisposing to Burkholderia pseudomallei infection and co-morbid diabetes. Homozygous db/db (diabetic) mice developed extreme obesity, dyslipidaemia and glucose intolerance leading to hyperglycaemia and overt type 2 diabetes. Compared to their heterozygous db/+ (non-diabetic) littermates, diabetic mice rapidly succumbed to subcutaneous B. pseudomallei infection, paralleled by severe hypoglycaemia and increased expression of the proinflammatory cytokines, tumour necrosis factor (TNF)-α and interleukin (IL)-1β, in the spleen, despite comparable bacterial loads in the spleen of non-diabetic mice. Neutrophil oxidative burst and dendritic cell uptake and killing of B. pseudomallei were similar between diabetic and non-diabetic mice. Compared to peritoneal macrophages from non-diabetic mice, macrophages from diabetic mice were unable to contain and kill B. pseudomallei. Functional differences between macrophages of diabetic and non-diabetic mice toward B. pseudomallei may contribute to rapid dissemination and more severe disease progression in hosts with co-morbid type 2 diabetes. 相似文献
992.
Martin SH Wingfield BD Wingfield MJ Steenkamp ET 《Fungal genetics and biology : FG & B》2011,48(7):731-740
Mating type genes are central to sexual reproduction and compatibility in Ascomycete fungi. However the "MAT" loci experience unique evolutionary pressures that can result in rapid divergence and enhanced inter-specific gene-flow (lateral gene transfer). In this study, molecular evolution of MAT loci was considered using the genus Fusarium (Teleomorph: Gibberella) as a model. Both MAT1-1 and MAT1-2 "idiomorphs" from eleven species of the Gibberellafujikuroi species complex were sequenced. Molecular evolution of the MAT loci from these heterothallic (self-sterile) species was compared with that of the MAT loci from nine homothallic (self-fertile) species in the Fusariumgraminearum species complex. Although Fusarium has previously been thought to have the same complement of four MAT genes that are found in Neurospora, we found evidence of a novel gene, MAT1-2-3, that may be specific to the Hypocreales. All MAT genes share a similar set of cis-regulatory motifs, although homothallic species might have recruited novel regulatory elements, which could potentially facilitate alternate expression of MAT1-1-1 and MAT1-2-1. FusariumMAT loci displayed evidence consistent with historical lateral gene-flow. Most notably, the MAT1-1 idiomorph of Fusariumsacchari appears to be unrelated to those of other species in the G.fujikuroi complex. In general, FusariumMAT genes are highly divergent. Both positive selection and relaxed selective constraint could account for this phenomenon. However, the extent of both recombination and inter-specific gene-flow in the MAT locus also appears to affect the rate of divergence. 相似文献
993.
A new species of Coulmannia, Coulmannia rossensis, is described from the Ross Sea, Antarctica. It is most similar to Coulmannia ramosae Castelló, 2004, but can easily be distinguished from this species bythe males yielding a pair of granulate humps on the dorsum of the pereonites 1-6 and a single granulate hump on the pereonite 7 and the free pleonite. Coulmannia rossensissp. n. is sexually dimorphic. The dorsal sculpture of the female bodies yield a single granulate hump on all the pereonites and free pleonite. The species of the genus Coulmannia are restricted to the Southern Ocean, and Coulmannia rossensissp. n. is the fourth species included in it. 相似文献
994.
Background aimsA hierarchy of endothelial colony-forming cells (ECFC) with different levels of proliferative potential has been identified in human circulating blood and blood vessels. ECFC has recently become an attractive target for new vascular regenerative therapies; however, in vitro expansion of ECFC typically depends on the presence of fetal bovine serum (FBS) or fetal calf serum (FCS) in the culture medium, which is not appropriate for its therapeutic application.MethodsTo identify optimal conditions for in vitro expansion of ECFC, the effects of human endothelial serum-free medium (SFM) supplemented with six pro-angiogenic cytokines and human umbilical cord blood plasma (HCP) were investigated. The in vitro morphology, proliferation, surface antigen expression and in vivo vessel-forming ability were utilized for examining the effects of medium on ECFC.ResultsThis novel formulation of endothelial cell culture medium allows us, for the first time, to isolate and expand human ECFC efficiently in vitro with a low concentration of HCP (1.5%) and without bovine serum additives. In this serum-reduced medium (SRM), human ECFC colony yields remained quantitatively similar to those cultured in a high concentration (10%) of bovine serum-supplemented medium. SRM-cultured ECFC displayed a robust clonal proliferative ability in vitro and human vessel-forming capacity in vivo.ConclusionsThe present study provides a novel method for the expansion of human ECFC in vitro and will help to advance approaches for using the cells in human therapeutic trials. 相似文献
995.
Michaut M Baryshnikova A Costanzo M Myers CL Andrews BJ Boone C Bader GD 《PLoS computational biology》2011,7(2):e1001092
If perturbing two genes together has a stronger or weaker effect than expected, they are said to genetically interact. Genetic interactions are important because they help map gene function, and functionally related genes have similar genetic interaction patterns. Mapping quantitative (positive and negative) genetic interactions on a global scale has recently become possible. This data clearly shows groups of genes connected by predominantly positive or negative interactions, termed monochromatic groups. These groups often correspond to functional modules, like biological processes or complexes, or connections between modules. However it is not yet known how these patterns globally relate to known functional modules. Here we systematically study the monochromatic nature of known biological processes using the largest quantitative genetic interaction data set available, which includes fitness measurements for ~5.4 million gene pairs in the yeast Saccharomyces cerevisiae. We find that only 10% of biological processes, as defined by Gene Ontology annotations, and less than 1% of inter-process connections are monochromatic. Further, we show that protein complexes are responsible for a surprisingly large fraction of these patterns. This suggests that complexes play a central role in shaping the monochromatic landscape of biological processes. Altogether this work shows that both positive and negative monochromatic patterns are found in known biological processes and in their connections and that protein complexes play an important role in these patterns. The monochromatic processes, complexes and connections we find chart a hierarchical and modular map of sensitive and redundant biological systems in the yeast cell that will be useful for gene function prediction and comparison across phenotypes and organisms. Furthermore the analysis methods we develop are applicable to other species for which genetic interactions will progressively become more available. 相似文献
996.
Zhai G Teumer A Stolk L Perry JR Vandenput L Coviello AD Koster A Bell JT Bhasin S Eriksson J Eriksson A Ernst F Ferrucci L Frayling TM Glass D Grundberg E Haring R Hedman AK Hofman A Kiel DP Kroemer HK Liu Y Lunetta KL Maggio M Lorentzon M Mangino M Melzer D Miljkovic I;MuTHER Consortium Nica A Penninx BW Vasan RS Rivadeneira F Small KS Soranzo N Uitterlinden AG Völzke H Wilson SG Xi L Zhuang WV Harris TB Murabito JM Ohlsson C Murray A de Jong FH Spector TD Wallaschofski H 《PLoS genetics》2011,7(4):e1002025
Dehydroepiandrosterone sulphate (DHEAS) is the most abundant circulating steroid secreted by adrenal glands--yet its function is unknown. Its serum concentration declines significantly with increasing age, which has led to speculation that a relative DHEAS deficiency may contribute to the development of common age-related diseases or diminished longevity. We conducted a meta-analysis of genome-wide association data with 14,846 individuals and identified eight independent common SNPs associated with serum DHEAS concentrations. Genes at or near the identified loci include ZKSCAN5 (rs11761528; p = 3.15 × 10(-36)), SULT2A1 (rs2637125; p = 2.61 × 10(-19)), ARPC1A (rs740160; p = 1.56 × 10(-16)), TRIM4 (rs17277546; p = 4.50 × 10(-11)), BMF (rs7181230; p = 5.44 × 10(-11)), HHEX (rs2497306; p = 4.64 × 10(-9)), BCL2L11 (rs6738028; p = 1.72 × 10(-8)), and CYP2C9 (rs2185570; p = 2.29 × 10(-8)). These genes are associated with type 2 diabetes, lymphoma, actin filament assembly, drug and xenobiotic metabolism, and zinc finger proteins. Several SNPs were associated with changes in gene expression levels, and the related genes are connected to biological pathways linking DHEAS with ageing. This study provides much needed insight into the function of DHEAS. 相似文献
997.
Together we are stronger: fusion protects mitochondria from autophagosomal degradation 总被引:1,自引:0,他引:1
Starvation induces a protective process of self-cannibalization called autophagy that is thought to mediate nonselective degradation of cytoplasmic material. We recently reported that mitochondria escape autophagosomal degradation through extensive fusion into mitochondrial networks upon certain starvation conditions. The extent of mitochondrial elongation is dependent on the type of nutrient deprivation, with amino acid depletion having a particularly strong effect. Downregulation of the mitochondrial fission protein Drp1 was determined to be important in bringing about starvation-induced mitochondrial fusion. The formation of mitochondrial networks during nutrient depletion selectively blocked their autophagic degradation, presumably allowing cells to sustain efficient ATP production and thereby survive starvation. 相似文献
998.
999.
The persistence of biological systems requires evolved mechanisms which promote stability. Cohesive primate social groups are one example of stable biological systems, which persist in spite of regular conflict. We suggest that genetic relatedness and its associated kinship structure are a potential source of stability in primate social groups as kinship structure is an important organizing principle in many animal societies. We investigated the effect of average genetic relatedness per matrilineal family on the stability of matrilineal grooming and agonistic interactions in 48 matrilines from seven captive groups of rhesus macaques. Matrilines with low average genetic relatedness show increased family-level instability such as: more sub-grouping in their matrilineal groom network, more frequent fighting with kin, and higher rates of wounding. Family-level instability in multiple matrilines within a group is further associated with group-level instability such as increased wounding. Stability appears to arise from the presence of clear matrilineal structure in the rhesus macaque group hierarchy, which is derived from cohesion among kin in their affiliative and agonistic interactions with each other. We conclude that genetic relatedness and kinship structure are an important source of group stability in animal societies, particularly when dominance and/or affilative interactions are typically governed by kinship. 相似文献
1000.
Bélard S Issifou S Hounkpatin AB Schaumburg F Ngoa UA Esen M Fendel R de Salazar PM Mürbeth RE Milligan P Imbault N Imoukhuede EB Theisen M Jepsen S Noor RA Okech B Kremsner PG Mordmüller B 《PloS one》2011,6(7):e22525