396 research outputs found
Inhibition of \u3cem\u3eRhizobium etli\u3c/em\u3e Polysaccharide Mutants by \u3cem\u3ePhaseolus vulgaris\u3c/em\u3e Root Compounds
Crude bean root extracts of Phaseolus vulgaris were tested for inhibition of the growth of several polysaccharide mutants of Rhizobium etli biovar phaseoli CE3. Mutants deficient only in exopolysaccharide and some mutants deficient only in the O-antigen of the lipopolysaccharide were no more sensitive than the wild-type strain to the extracts, whereas mutants defective in both lipopolysaccharide and exopolysaccharide were much more sensitive. The inhibitory activity was found at much higher levels in roots and nodules than in stems or leaves. Inoculation with either wild-type or polysaccharide-deficient R. etli did not appear to affect the level of activity. Sequential extractions of the crude root material with petroleum ether, ethyl acetate, methanol, and water partitioned inhibitory activity into each solvent except methanol. The major inhibitors in the petroleum ether and ethyl acetate extracts were purified by C18 high-performance liquid chromatography. These compounds all migrated very similarly in both liquid and thin-layer chromatography but were distinguished by their mass spectra. Absorbance spectra and fluorescence properties suggested that they were coumestans, one of which had the mass spectrum and nuclear magnetic resonances of coumestrol. These results are discussed with regard to the hypothesis that one role of rhizobial polysaccharides is to protect against plant toxins encountered during nodule development
Characterization of five members of the actin gene family in the sea urchin
Hybridization of an actin cDNA clone (pSA38) to restriction enzyme digests of Strongylocentrotus purpuratus DNA indicates that the sea urchin genome contains at least five different actin genes. A sea urchin genomic clone library was screened for recombinants which hydridize to pSA38 and four genomic clones were isolated. Restriction maps were generated which indicate that three of these recombinants contain different actin genes, and that the fourth may be an allele to one of these. The restriction maps suggest that one clone contains two linked actin genes. This fact, which was confirmed by heteroduplex analysis, indicates that the actin gene family may be clustered. The linked genes are oriented in the same direction and spaced about 8.0 kilobases apart. In heteroduplexes between genomic clones two intervening sequences were seen. Significant homology is confined to the actin coding region and does not include any flanking sequence. Southern blot analysis reveals that repetitive DNA sequences are found in the region of the actin genes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24164/1/0000422.pd
A Systematic Mapping Approach of 16q12.2/FTO and BMI in More Than 20,000 African Americans Narrows in on the Underlying Functional Variation: Results from the Population Architecture using Genomics and Epidemiology (PAGE) Study
Genetic variants in intron 1 of the fat mass- and obesity-associated (FTO) gene have been consistently associated with body mass index (BMI) in Europeans. However, follow-up studies in African Americans (AA) have shown no support for some of the most consistently BMI-associated FTO index single nucleotide polymorphisms (SNPs). This is most likely explained by different race-specific linkage disequilibrium (LD) patterns and lower correlation overall in AA, which provides the opportunity to fine-map this region and narrow in on the functional variant. To comprehensively explore the 16q12.2/FTO locus and to search for second independent signals in the broader region, we fine-mapped a 646-kb region, encompassing the large FTO gene and the flanking gene RPGRIP1L by investigating a total of 3,756 variants (1,529 genotyped and 2,227 imputed variants) in 20,488 AAs across five studies. We observed associations between BMI and variants in the known FTO intron 1 locus: the SNP with the most significant p-value, rs56137030 (8.3Ă10-6) had not been highlighted in previous studies. While rs56137030was correlated at r2>0.5 with 103 SNPs in Europeans (including the GWAS index SNPs), this number was reduced to 28 SNPs in AA. Among rs56137030 and the 28 correlated SNPs, six were located within candidate intronic regulatory elements, including rs1421085, for which we predicted allele-specific binding affinity for the transcription factor CUX1, which has recently been implicated in the regulation of FTO. We did not find strong evidence for a second independent signal in the broader region. In summary, this large fine-mapping study in AA has substantially reduced the number of common alleles that are likely to be functional candidates of the known FTO locus. Importantly our study demonstrated that comprehensive fine-mapping in AA provides a powerful approach to narrow in on the functional candidate(s) underlying the initial GWAS findings in European populations
Evidence for Direct CP Violation in B0 -> K+- pi-+ Decays
We report evidence for direct CP violation in the decay B0 -> K+-pi-+ with
253/fb of data collected with the Belle detector at the KEKB e+e- collider.
Using 275 million B B_bar pairs we observe a B -> K+-pi-+ signal with 2140+-53
events. The measured CP violating asymmetry is Acp(K+-pi-+) = -0.101+-0.025
(stat)+-0.005 (syst), corresponding to a significance of 3.9 sigma including
systematics. We also search for CP violation in the decays B+- -> K+-pi0 and
B+- -> pi+-pi0. The measured CP violating asymmetries are Acp(K+-pi0) =
0.04+-0.05(stat)+-0.02(syst) and Acp(pi+-pi0) = -0.02+-0.10(stat)+-0.01(syst),
corresponding to the intervals -0.05 < Acp(K+-pi0) < 0.13 and
-0.18<Acp(pi+-pi0)<0.14 at 90% confidence level.Comment: 9 pages, 3 figures. submitted to Physical Review Letter
Searching for the in-plane Galactic bar and ring in DENIS
New evidence for a long thin Galactic bar (in contradistinction to the
bulge), as well as for the existence of the ring and the truncation of the
inner disc, are sought in the DENIS survey. First, we examine DENIS and Two
Micron Galactic Survey star counts for the characteristic signatures of an
in-plane bar and ring. The star counts in the plane for 30 deg.>l>-30 deg. are
shown to be highly asymmetric with considerably more sources at positive than
at negative longitudes. At |b|\approx 1.5 deg., however, the counts are nearly
symmetric. Therefore, the asymmetry is not due to the disc, which is shown to
have an inner truncation, or to the bulge, so there has to be another major
component in the inner Galaxy that is causing the asymmetries. This component
provides up to 50% of the detected sources in the plane between the bulge and
l=27 deg. or l=-14 deg. This component is shown to be consistent with an
in-plane bar with a position angle of 40 deg. and half-length of 3.9 kpc.
However, there is also a major peak in the counts at l=-22 deg., which
coincides with the tangential point of the so-called 3 kpc arm. This is shown
to be most probably a ring or a pseudo-ring. The extinction in the plane is
also shown to be asymmetric with more extinction at negative than at positive
longitudes. For l<8 deg. the extinction is shown to be slightly tilted with
respect to b=0 deg. in the same manner as the HI disc. We conclude that the
Galaxy is a fairly typical ringed barred spiral galaxy.Comment: 15 pages, 10 figures, accepted in A&
Fifteen new risk loci for coronary artery disease highlight arterial-wall-specific mechanisms
Coronary artery disease (CAD) is a leading cause of morbidity and mortality worldwide. Although 58 genomic regions have been associated with CAD thus far, most of the heritability is unexplained, indicating that additional susceptibility loci await identification. An efficient discovery strategy may be larger-scale evaluation of promising associations suggested by genome-wide association studies (GWAS). Hence, we genotyped 56,309 participants using a targeted gene array derived from earlier GWAS results and performed meta-analysis of results with 194,427 participants previously genotyped, totaling 88,192 CAD cases and 162,544 controls. We identified 25 new SNP-CAD associations (P < 5 Ă 10(-8), in fixed-effects meta-analysis) from 15 genomic regions, including SNPs in or near genes involved in cellular adhesion, leukocyte migration and atherosclerosis (PECAM1, rs1867624), coagulation and inflammation (PROCR, rs867186 (p.Ser219Gly)) and vascular smooth muscle cell differentiation (LMOD1, rs2820315). Correlation of these regions with cell-type-specific gene expression and plasma protein levels sheds light on potential disease mechanisms
Age-dependent changes in mean and variance of gene expression across tissues in a twin cohort.
Indian community health insurance schemes provide partial protection against catastrophic health expenditure
BACKGROUND: More than 72% of health expenditure in India is financed by individual households at the time of illness through out-of-pocket payments. This is a highly regressive way of financing health care and sometimes leads to impoverishment. Health insurance is recommended as a measure to protect households from such catastrophic health expenditure (CHE). We studied two Indian community health insurance (CHI) schemes, ACCORD and SEWA, to determine whether insured households are protected from CHE. METHODS: ACCORD provides health insurance cover for the indigenous population, living in Gudalur, Tamil Nadu. SEWA provides insurance cover for self employed women in the state of Gujarat. Both cover hospitalisation expenses, but only upto a maximum limit of US45, respectively. We reviewed the insurance claims registers in both schemes and identified patients who were hospitalised during the period 01/04/2003 to 31/03/2004. Details of their diagnoses, places and costs of treatment and self-reported annual incomes were obtained. There is no single definition of CHE and none of these have been validated. For this research, we used the following definition; "annual hospital expenditure greater than 10% of annual income," to identify those who experienced CHE. RESULTS: There were a total of 683 and 3152 hospital admissions at ACCORD and SEWA, respectively. In the absence of the CHI scheme, all of the patients at ACCORD and SEWA would have had to pay OOP for their hospitalisation. With the CHI scheme, 67% and 34% of patients did not have to make any out-of-pocket (OOP) payment for their hospital expenses at ACCORD and SEWA, respectively. Both CHI schemes halved the number of households that would have experienced CHE by covering hospital costs. However, despite this, 4% and 23% of households with admissions still experienced CHE at ACCORD and SEWA, respectively. This was related to the following conditions: low annual income, benefit packages with low maximum limits, exclusion of some conditions from the benefit package, and use of the private sector for admissions. CONCLUSION: CHI appears to be effective at halving the incidence of CHE among hospitalised patients. This protection could be further enhanced by improving the design of the CHI schemes, especially by increasing the upper limits of benefit packages, minimising exclusions and controlling costs
Genome-Wide Assessments Reveal Extremely High Levels of Polymorphism of Two Active Families of Mouse Endogenous Retroviral Elements
Endogenous retroviral elements (ERVs) in mice are significant genomic mutagens, causing âŒ10% of all reported spontaneous germ line mutations in laboratory strains. The majority of these mutations are due to insertions of two high copy ERV families, the IAP and ETn/MusD elements. This significant level of ongoing retrotranspositional activity suggests that inbred mice are highly variable in content of these two ERV groups. However, no comprehensive genome-wide studies have been performed to assess their level of polymorphism. Here we compared three test strains, for which sufficient genomic sequence is available, to each other and to the reference C57BL/6J genome and detected very high levels of insertional polymorphism for both ERV families, with an estimated false discovery rate of only 0.4%. Specifically, we found that at least 60% of IAP and 25% of ETn/MusD elements detected in any strain are absent in one or more of the other three strains. The polymorphic nature of a set of 40 ETn/MusD elements found within gene introns was confirmed using genomic PCR on DNA from a panel of mouse strains. For some cases, we detected gene-splicing abnormalities involving the ERV and obtained additional evidence for decreased gene expression in strains carrying the insertion. In total, we identified nearly 700 polymorphic IAP or ETn/MusD ERVs or solitary LTRs that reside in gene introns, providing potential candidates that may contribute to gene expression differences among strains. These extreme levels of polymorphism suggest that ERV insertions play a significant role in genetic drift of mouse lines
Genome-Wide Assessments Reveal Extremely High Levels of Polymorphism of Two Active Families of Mouse Endogenous Retroviral Elements
Endogenous retroviral elements (ERVs) in mice are significant genomic mutagens, causing âŒ10% of all reported spontaneous germ line mutations in laboratory strains. The majority of these mutations are due to insertions of two high copy ERV families, the IAP and ETn/MusD elements. This significant level of ongoing retrotranspositional activity suggests that inbred mice are highly variable in content of these two ERV groups. However, no comprehensive genome-wide studies have been performed to assess their level of polymorphism. Here we compared three test strains, for which sufficient genomic sequence is available, to each other and to the reference C57BL/6J genome and detected very high levels of insertional polymorphism for both ERV families, with an estimated false discovery rate of only 0.4%. Specifically, we found that at least 60% of IAP and 25% of ETn/MusD elements detected in any strain are absent in one or more of the other three strains. The polymorphic nature of a set of 40 ETn/MusD elements found within gene introns was confirmed using genomic PCR on DNA from a panel of mouse strains. For some cases, we detected gene-splicing abnormalities involving the ERV and obtained additional evidence for decreased gene expression in strains carrying the insertion. In total, we identified nearly 700 polymorphic IAP or ETn/MusD ERVs or solitary LTRs that reside in gene introns, providing potential candidates that may contribute to gene expression differences among strains. These extreme levels of polymorphism suggest that ERV insertions play a significant role in genetic drift of mouse lines
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