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High Significance (high + significance)
Selected AbstractsSingle QTL mapping and nucleotide-level resolution of a physiologic trait in wine Saccharomyces cerevisiae strainsFEMS YEAST RESEARCH, Issue 6 2007Philippe Marullo Abstract Natural Saccharomyces cerevisiae yeast strains exhibit very large genotypic and phenotypic diversity. However, the link between phenotype variation and genetic determinism is still difficult to identify, especially in wild populations. Using genome hybridization on DNA microarrays, it is now possible to identify single-feature polymorphisms among divergent yeast strains. This tool offers the possibility of applying quantitative genetics to wild yeast strains. In this instance, we studied the genetic basis for variations in acetic acid production using progeny derived from two strains from grape must isolates. The trait was quantified during alcoholic fermentation of the two strains and 108 segregants derived from their crossing. A genetic map of 2212 markers was generated using oligonucleotide microarrays, and a major quantitative trait locus (QTL) was mapped with high significance. Further investigations showed that this QTL was due to a nonsynonymous single-nucleotide polymorphism that targeted the catalytic core of asparaginase type I (ASP1) and abolished its activity. This QTL was only effective when asparagine was used as a major nitrogen source. Our results link nitrogen assimilation and CO2 production rate to acetic acid production, as well as, on a broader scale, illustrating the specific problem of quantitative genetics when working with nonlaboratory microorganisms. [source] Transcriptional profiling on chromosome 19p indicated frequent downregulation of ACP5 expression in hepatocellular carcinomaINTERNATIONAL JOURNAL OF CANCER, Issue 6 2005Kathy Y.-Y. Abstract Chromosomal rearrangements unraveled by spectral karyotyping (SKY) indicated frequent chromosome 19 translocations in hepatocellular carcinoma (HCC). In an effort to characterize the aberrant 19 rearrangements in HCC, we performed positional mapping by fluorescence in-situ hybridization (FISH) in 10 HCC cell lines. SKY analysis indicated structural rearrangements of chromosome 19 in 6 cell lines, 4 of which demonstrated recurring 19p translocations with different partner chromosomes. Using fluorescence-labeled BAC probes, physical mapping indicated a breakpoint cluster between 19p13.12 and 19p12. A corresponding transcriptional mapping by cDNA array on 19p suggested the differential expression of a single downregulated gene ACP5 (tartrate-resistant acid phosphatase type 5). Quantitative RT-PCR confirmed the reduced expression of ACP5 and indicated a strong correlation of its repressed expression only in cell lines that contain a 19p rearrangement (p = 0.004). We further examined the expression of ACP5 in a cohort of 82 primary tumors and 74 matching nonmalignant liver tissues. In the primary HCC examined, a reduction of ACP5 transcripts by 2 to as much as 1,000-fold was suggested in 67% of tumors (55/82 cases). When compared to adjacent nonmalignant tissues, 46% of tumors (34/74 cases) demonstrated a lower expression level (p = 0.015). On closer examination, a high significance of ACP5 repression was suggested in the cirrhotic HCC subgroup that was derived from chronic hepatitis B infected patients (55%; 30/54 cases; p = 0.001). Functional examination of ACP5 ectopic expression in HCC cells further demonstrated a significant growth inhibitory effect of ACP5 on tumor cell survival (p < 0.001). In our study, the novel finding of common ACP5 downregulation in HCC may provide basis for further investigations on the role of acid phosphatase in hepatocarcinogenesis. © 2004 Wiley-Liss, Inc. [source] Prevalence and predictors of osteoporosis and the impact of life style factors on bone mineral densityINTERNATIONAL JOURNAL OF RHEUMATIC DISEASES, Issue 3 2007Abdulbari BENER Abstract Aim:, The aim of this study was to determine the prevalence and predictors of osteoporosis and the impact of life style factors on bone mineral density (BMD) in premenopausal and postmenopausal Qatari women. Methods:, This is a cross-sectional study. A total of 821 healthy Qatari women aged 20,70 years had given consent and participated and the study was conducted from June 2005 to December 2006 at the Rumaillah Hospital, Hamad Medical Corporation (HMC), Doha, State of Qatar. All subjects completed a questionnaire on reproductive and life style factors. Height and weight were measured. All subjects underwent dual-energy X-ray absorptiometry (DXA) to determine factors influencing BMD of the spine and femur. The main outcome measures were menopausal status, socio-demographic and lifestyle factors and BMD measurements. Results:, The prevalence of osteoporosis in postmenopausal women was 12.3%. BMI was significantly higher among postmenopausal women (P < 0.001) when compared to premenopausal women. The subjects who regularly consumed dairy products had better BMD at spine, neck and ward sites (P < 0.05). Those doing regular household work for 3,4 h a week had higher BMD at all sites compared to those who did not do their own household work. Multiple regression analysis showed that education level and body mass index were strong positive predictors showing high significance. Conclusion:, The relation between lifestyle and BMD were explored in Qatari women. The prevalence of osteoporosis in Qatari women is comparable to other countries. BMD values were higher in women who were taking diary products regularly, and were involved with household work. [source] Hydrogen-bonding versus,,, stacking interactions in dipyrido[f,h]quinoxaline-6,7-dicarbonitrile and 6,7-dicyanodipyrido[f,h]quinoxalin-1-ium chloride dihydrateACTA CRYSTALLOGRAPHICA SECTION C, Issue 9 2008Leonid Kozlov The solvent-free title compound, C16H6N6, is an aromatic derivative of phenanthroline with an extended , system. It exhibits a remarkable ,,, columnar stacking in the crystal structure, with interplanar distances of 3.229,(3) and 3.380,(3),Å, the shorter spacing being between the two molecules within the asymmetric unit. Adjacent units along the stacked arrays are rotated in-plane with respect to one another by approximately 120°. The hydrochloride derivative, C16H7N6+·Cl,·2H2O, in which one of the phenanthroline N atoms has been protonated, crystallized as a dihydrate. The supramolecular organization in this compound is characterized by continuous hydrogen bonding between the component species, yielding two-dimensional hydrogen-bonded networks. This study demonstrates the high significance of the ,,, stacking interactions in the solvent-free aromatic system and how they can be undermined by introducing hydrogen-bonding capacity into the ligand. [source] Rapid range expansion of a wing-dimorphic bush-cricket after the 2003 climatic anomalyBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2009AXEL HOCHKIRCH During recent decades, many species have responded to global warming by poleward range expansions. We require a better mechanistic understanding of the nature and extent of such processes to assess how climate change might affect biodiversity. Wing-dimorphic bush-crickets are excellent objects to study dispersal and colonization processes at the range margin because the long-winged morphs (macropters) represent dispersal units of otherwise flightless species. Moreover, these insects produce noisy songs and can easily be mapped. The present study comprised a detailed investigation of the population dynamics and genetics at the edge of the range of Roesel's bush-cricket, Metrioptera roeselii. We mapped the distribution of this insect in a previously unoccupied area of 185 km2 and examined the genetic structure at the range margin using four polymorphic microsatellite loci. The results obtained demonstrate that the European heat wave in 2003 induced a strong immigration of macropters in the area stemming from multiple sources, whereas only few immigrants were recorded in the two subsequent years. Macropters were genotyped in a distance of up to 19.1 km from their origin, considerably exceeding the known dispersal distances for this species. Moreover, the data show that strong local founder effects are equalized on a large scale by the high number of immigrants from multiple sources. The present study demonstrates that macropters are of high significance for the range expansion of wing-dimorphic insects because a single-year climatic anomaly can induce strong dispersal processes. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 97, 118,127. [source] | |||||||||||||