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Sample records for pm3 resistance locus

  1. Unlocking wheat genetic resources for the molecular identification of previously undescribed functional alleles at the Pm3 resistance locus

    PubMed Central

    Bhullar, Navreet K.; Street, Kenneth; Mackay, Michael; Yahiaoui, Nabila; Keller, Beat

    2009-01-01

    The continuous improvement of crop plants is essential for agriculture in the coming decades and relies on the use of genetic variability through breeding. However, domestication and modern breeding have reduced diversity in the crop germplasm. Global gene banks conserve diversity, but these resources remain underexplored owing to a lack of efficient strategies to isolate important alleles. Here we describe a large-scale allele-mining project at the molecular level. We first selected a set of 1,320 bread wheat landraces from a database of 16,089 accessions, using the focused identification of germplasm strategy. On the basis of a hierarchical selection procedure on this set, we then isolated 7 resistance alleles of the powdery mildew resistance gene Pm3, doubling the known functional allelic diversity at this locus. This targeted approach for molecular utilization of gene bank accessions reveals landraces as a rich resource of new functional alleles. This strategy can be implemented for other studies on the molecular diversity of agriculturally important genes, as well as for molecular breeding. PMID:19470492

  2. Unlocking wheat genetic resources for the molecular identification of previously undescribed functional alleles at the Pm3 resistance locus.

    PubMed

    Bhullar, Navreet K; Street, Kenneth; Mackay, Michael; Yahiaoui, Nabila; Keller, Beat

    2009-06-01

    The continuous improvement of crop plants is essential for agriculture in the coming decades and relies on the use of genetic variability through breeding. However, domestication and modern breeding have reduced diversity in the crop germplasm. Global gene banks conserve diversity, but these resources remain underexplored owing to a lack of efficient strategies to isolate important alleles. Here we describe a large-scale allele-mining project at the molecular level. We first selected a set of 1,320 bread wheat landraces from a database of 16,089 accessions, using the focused identification of germplasm strategy. On the basis of a hierarchical selection procedure on this set, we then isolated 7 resistance alleles of the powdery mildew resistance gene Pm3, doubling the known functional allelic diversity at this locus. This targeted approach for molecular utilization of gene bank accessions reveals landraces as a rich resource of new functional alleles. This strategy can be implemented for other studies on the molecular diversity of agriculturally important genes, as well as for molecular breeding. PMID:19470492

  3. Rye-derived powdery mildew resistance gene Pm8 in wheat is suppressed by the Pm3 locus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic suppression of disease resistance is occasionally observed in hexaploid wheat or in its interspecific crosses. The phenotypic effects of genes moved to wheat from relatives with lower ploidy are often smaller than in the original sources, suggesting the presence of modifiers or partial inhib...

  4. Multiple Avirulence Loci and Allele-Specific Effector Recognition Control the Pm3 Race-Specific Resistance of Wheat to Powdery Mildew[OPEN

    PubMed Central

    Roffler, Stefan; Stirnweis, Daniel; Treier, Georges; Herren, Gerhard; Korol, Abraham B.; Wicker, Thomas

    2015-01-01

    In cereals, several mildew resistance genes occur as large allelic series; for example, in wheat (Triticum aestivum and Triticum turgidum), 17 functional Pm3 alleles confer agronomically important race-specific resistance to powdery mildew (Blumeria graminis). The molecular basis of race specificity has been characterized in wheat, but little is known about the corresponding avirulence genes in powdery mildew. Here, we dissected the genetics of avirulence for six Pm3 alleles and found that three major Avr loci affect avirulence, with a common locus_1 involved in all AvrPm3-Pm3 interactions. We cloned the effector gene AvrPm3a2/f2 from locus_2, which is recognized by the Pm3a and Pm3f alleles. Induction of a Pm3 allele-dependent hypersensitive response in transient assays in Nicotiana benthamiana and in wheat demonstrated specificity. Gene expression analysis of Bcg1 (encoded by locus_1) and AvrPm3 a2/f2 revealed significant differences between isolates, indicating that in addition to protein polymorphisms, expression levels play a role in avirulence. We propose a model for race specificity involving three components: an allele-specific avirulence effector, a resistance gene allele, and a pathogen-encoded suppressor of avirulence. Thus, whereas a genetically simple allelic series controls specificity in the plant host, recognition on the pathogen side is more complex, allowing flexible evolutionary responses and adaptation to resistance genes. PMID:26452600

  5. Wheat gene bank accessions as a source of new alleles of the powdery mildew resistance gene Pm3: a large scale allele mining project

    PubMed Central

    2010-01-01

    Background In the last hundred years, the development of improved wheat cultivars has led to the replacement of landraces and traditional varieties by modern cultivars. This has resulted in a decline in the genetic diversity of agriculturally used wheat. However, the diversity lost in the elite material is somewhat preserved in crop gene banks. Therefore, the gene bank accessions provide the basis for genetic improvement of crops for specific traits and and represent rich sources of novel allelic variation. Results We have undertaken large scale molecular allele mining to isolate new alleles of the powdery mildew resistance gene Pm3 from wheat gene bank accessions. The search for new Pm3 alleles was carried out on a geographically diverse set of 733 wheat accessions originating from 20 countries. Pm3 specific molecular tools as well as classical pathogenicity tests were used to characterize the accessions. Two new functional Pm3 alleles were identified out of the eight newly cloned Pm3 sequences. These new resistance alleles were isolated from accessions from China and Nepal. Thus, the repertoire of functional Pm3 alleles now includes 17 genes, making it one of the largest allelic series of plant resistance genes. The combined information on resistant and susceptible Pm3 sequences will allow to study molecular function and specificity of functional Pm3 alleles. Conclusions This study demonstrates that molecular allele mining on geographically defined accessions is a useful strategy to rapidly characterize the diversity of gene bank accessions at a specific genetic locus of agronomical importance. The identified wheat accessions with new resistance specificities can be used for marker-assisted transfer of the Pm3 alleles to modern wheat lines. PMID:20470444

  6. Molecular cloning, functional verification, and evolution of TmPm3, the powdery mildew resistance gene of Triticum monococcum L.

    PubMed

    Zhao, C Z; Li, Y H; Dong, H T; Geng, M M; Liu, W H; Li, F; Ni, Z F; Wang, X J; Xie, C J; Sun, Q X

    2016-01-01

    Powdery mildew (Pm) is one of the most harmful diseases in wheat. Three Pm-resistance genes, Pm3, Pm21, and Pm8, have been cloned but most Pm3/Pm8 alleles have lost their resistance to Pm in hexaploid wheat. In this study, a new Pm3 homolog gene (TmPm3) was isolated from Triticum monococcum L. using a homology-based cloning strategy, being the first report of a functional Pm3 homolog gene from a diploid wheat species. The transient expression of TmPm3 in leaf epidermal cells showed that over-expressed TmPm3 could significantly inhibit the penetration of Blumeria graminis f. sp tritici conidia spores and the formation of haustoria. Sequence analysis of Pm3 alleles shed new light on the evolution of Pm3 genes, providing a better understanding of the molecular basis of disease resistance. This study also suggested that homology-based cloning of resistance genes is a feasible method for the isolation of functional resistance genes from wheat germplasm. PMID:27173250

  7. Identification of Pm8 Suppressor at Pm3 Locus in Soft 1 Red Winter Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The 1BL.1RS wheat-rye translocation possesses the Pm8, Yr9, Lr26, and Sr31 genes for resistance to several major fungal pathogens of small grains. However, not all wheat cultivars with the 1RS translocation are resistant to Pm8-avirulent isolates of Blumeria graminis f. sp. tritici (Bgt), the causal...

  8. The barley Frost resistance-H2 locus.

    PubMed

    Pasquariello, Marianna; Barabaschi, Delfina; Himmelbach, Axel; Steuernagel, Burkhard; Ariyadasa, Ruvini; Stein, Nils; Gandolfi, Francesco; Tenedini, Elena; Bernardis, Isabella; Tagliafico, Enrico; Pecchioni, Nicola; Francia, Enrico

    2014-03-01

    Frost resistance-H2 (Fr-H2) is a major QTL affecting freezing tolerance in barley, yet its molecular basis is still not clearly understood. To gain a better insight into the structural characterization of the locus, a high-resolution linkage map developed from the Nure × Tremois cross was initially implemented to map 13 loci which divided the 0.602 cM total genetic distance into ten recombination segments. A PCR-based screening was then applied to identify positive bacterial artificial chromosome (BAC) clones from two genomic libraries of the reference genotype Morex. Twenty-six overlapping BACs from the integrated physical-genetic map were 454 sequenced. Reads assembled in contigs were subsequently ordered, aligned and manually curated in 42 scaffolds. In a total of 1.47 Mbp, 58 protein-coding sequences were identified, 33 of which classified according to similarity with sequences in public databases. As three complete barley C-repeat Binding Factors (HvCBF) genes were newly identified, the locus contained13 full-length HvCBFs, four Related to AP2 Triticeae (RAPT) genes, and at least five CBF pseudogenes. The final overall assembly of Fr-H2 includes more than 90 % of target region: all genes were identified along the locus, and a general survey of Repetitive Elements obtained. We believe that this gold-standard sequence for the Morex Fr-H2 will be a useful genomic tool for structural and evolutionary comparisons with Fr-H2 in winter-hardy cultivars along with Fr-2 of other Triticeae crops. PMID:24442711

  9. Mutations in the Plasmodium falciparum Cyclic Amine Resistance Locus (PfCARL) Confer Multidrug Resistance

    PubMed Central

    LaMonte, Gregory; Lim, Michelle Yi-Xiu; Wree, Melanie; Reimer, Christin; Nachon, Marie; Corey, Victoria; Gedeck, Peter; Plouffe, David; Du, Alan; Figueroa, Nelissa; Yeung, Bryan; Winzeler, Elizabeth A.

    2016-01-01

    ABSTRACT Mutations in the Plasmodium falciparum cyclic amine resistance locus (PfCARL) are associated with parasite resistance to the imidazolopiperazines, a potent class of novel antimalarial compounds that display both prophylactic and transmission-blocking activity, in addition to activity against blood-stage parasites. Here, we show that pfcarl encodes a protein, with a predicted molecular weight of 153 kDa, that localizes to the cis-Golgi apparatus of the parasite in both asexual and sexual blood stages. Utilizing clustered regularly interspaced short palindromic repeat (CRISPR)-mediated gene introduction of 5 variants (L830V, S1076N/I, V1103L, and I1139K), we demonstrate that mutations in pfcarl are sufficient to generate resistance against the imidazolopiperazines in both asexual and sexual blood-stage parasites. We further determined that the mutant PfCARL protein confers resistance to several structurally unrelated compounds. These data suggest that PfCARL modulates the levels of small-molecule inhibitors that affect Golgi-related processes, such as protein sorting or membrane trafficking, and is therefore an important mechanism of resistance in malaria parasites. PMID:27381290

  10. Tomato mutants altered in bacterial disease resistance provide evidence for a new locus controlling pathogen recognition.

    PubMed Central

    Salmeron, J M; Barker, S J; Carland, F M; Mehta, A Y; Staskawicz, B J

    1994-01-01

    We have employed a genetic approach to study the resistance of tomato to the phytopathogenic bacterium Pseudomonas syringae pv tomato. Resistance to P. s. tomato depends upon expression of the Pto locus in tomato, which encodes a protein with similarity to serine/threonine protein kinases and recognizes pathogen strains expressing the avirulence gene avrPto. Eleven tomato mutants were isolated with altered resistance to P. s. tomato strains expressing avrPto. We identified mutations both in the Pto resistance locus and in a new locus designated Prf (for Pseudomonas resistance and fenthion sensitivity). The genetic approach allowed us to dissect the roles of these loci in signal transduction in response to pathogen attack. Lines carrying mutations in the Pto locus vary 200-fold in the degree to which they are susceptible to P. s. tomato strains expressing avrPto. The pto mutants retain sensitivity to the organophosphate insecticide fenthion; this trait segregates with Pto in genetic crosses. This result suggested that contrary to previous hypotheses, the Pto locus controls pathogen recognition but not fenthion sensitivity. Interestingly, mutations in the prf locus result in both complete susceptibility to P. s. tomato and insensitivity to fenthion, suggesting that Prf plays a role in tomato signaling in response to both pathogen elicitors and fenthion. Because pto and prf mutations do not alter recognition of Xanthomonas campestris strains expressing avrBsP, an avirulence gene recognized by all tested tomato cultivars, Prf does not play a general role in disease resistance but possibly functions specifically in resistance against P. s. tomato. Genetic analysis of F2 populations from crosses of pto and prf homozygotes indicated that the Pto and Prf loci are tightly linked. PMID:7911348

  11. A novel quantitative trait locus for Fusarium head blight resistance in chromosome 7A of wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A Chinese Spring-Sumai 3 chromosome 7A disomic substitution line (CS-Sumai 3-7ADSL) was reported to have a high level of Fusarium head blight (FHB) resistance for symptom spread within a spike (Type II) and low deoxynivalenol accumulation in infected kernels (Type III), but quantitative trait locus ...

  12. Combined nickel-cobalt-cadmium resistance encoded by the ncc locus of Alcaligenes xylosoxidans 31A.

    PubMed Central

    Schmidt, T; Schlegel, H G

    1994-01-01

    The nickel-cobalt-cadmium resistance genes carried by plasmid pTOM9 of Alcaligenes xylosoxidans 31A are located on a 14.5-kb BamHI fragment. By random Tn5 insertion mutagenesis, the fragment was shown to contain two distinct nickel resistance loci, ncc and nre. The ncc locus causes a high-level combined nickel, cobalt, and cadmium resistance in strain AE104, which is a cured derivative of the metal-resistant bacterium Alcaligenes eutrophus CH34. ncc is not expressed in Escherichia coli. The nre locus causes low-level nickel resistance in both Alcaligenes and E. coli strains. The nucleotide sequence of the ncc locus revealed seven open reading frames designated nccYXHCBAN. The corresponding predicted proteins share strong similarities with proteins encoded by the metal resistance loci cnr (cnrYXHCBA) and czc (czcRCBAD) of A. eutrophus CH34. When different DNA fragments carrying ncc genes were heterologously expressed under the control of the bacteriophage T7 promoter, five protein bands representing NccA (116 kDa), NccB (40 kDa), NccC (46 kDa), NccN (23.5 kDa), and NccX (16.5 kDa) were detected. Images PMID:7961470

  13. Parallel Loss-of-Function at the RPM1 Bacterial Resistance Locus in Arabidopsis thaliana

    PubMed Central

    Rose, Laura; Atwell, Susanna; Grant, Murray; Holub, Eric B.

    2012-01-01

    Dimorphism at the Resistance to Pseudomonas syringae pv. maculicola 1 (RPM1) locus is well documented in natural populations of Arabidopsis thaliana and has been portrayed as a long-term balanced polymorphism. The haplotype from resistant plants contains the RPM1 gene, which enables these plants to recognize at least two structurally unrelated bacterial effector proteins (AvrB and AvrRpm1) from bacterial crop pathogens. A complete deletion of the RPM1 coding sequence has been interpreted as a single event resulting in susceptibility in these individuals. Consequently, the ability to revert to resistance or for alternative R-gene specificities to evolve at this locus has also been lost in these individuals. Our survey of variation at the RPM1 locus in a large species-wide sample of A. thaliana has revealed four new loss-of-function alleles that contain most of the intervening sequence of the RPM1 open reading frame. Multiple loss-of-function alleles may have originated due to the reported intrinsic cost to plants expressing the RPM1 protein. The frequency and geographic distribution of rpm1 alleles observed in our survey indicate the parallel origin and maintenance of these loss-of-function mutations and reveal a more complex history of natural selection at this locus than previously thought. PMID:23272006

  14. New parameterization of the PM3 method for monosaccharides

    NASA Astrophysics Data System (ADS)

    Mane, Jonathan Y.; Klobukowski, Mariusz

    2010-11-01

    We derived new parameters for the semi-empirical PM3 method, PM3MS, designed for studies of saccharides. The parameters were optimized using genetic algorithm procedure. We used the MP2/cc-pVTZ energies and optimized geometries of monosaccharides as the reference set. Results show that compared to the standard PM3, the new PM3MS parameters predict better ordering of the conformers energy both for the members of the training set, as well as those outside the training set.

  15. Evolution and selection of Rhg1, a copy-number variant nematode-resistance locus

    PubMed Central

    Lee, Tong Geon; Kumar, Indrajit; Diers, Brian W; Hudson, Matthew E

    2015-01-01

    The soybean cyst nematode (SCN) resistance locus Rhg1 is a tandem repeat of a 31.2 kb unit of the soybean genome. Each 31.2-kb unit contains four genes. One allele of Rhg1, Rhg1-b, is responsible for protecting most US soybean production from SCN. Whole-genome sequencing was performed, and PCR assays were developed to investigate allelic variation in sequence and copy number of the Rhg1 locus across a population of soybean germplasm accessions. Four distinct sequences of the 31.2-kb repeat unit were identified, and some Rhg1 alleles carry up to three different types of repeat unit. The total number of copies of the repeat varies from 1 to 10 per haploid genome. Both copy number and sequence of the repeat correlate with the resistance phenotype, and the Rhg1 locus shows strong signatures of selection. Significant linkage disequilibrium in the genome outside the boundaries of the repeat allowed the Rhg1 genotype to be inferred using high-density single nucleotide polymorphism genotyping of 15 996 accessions. Over 860 germplasm accessions were found likely to possess Rhg1 alleles. The regions surrounding the repeat show indications of non-neutral evolution and high genetic variability in populations from different geographic locations, but without evidence of fixation of the resistant genotype. A compelling explanation of these results is that balancing selection is in operation at Rhg1. PMID:25735447

  16. Genetic mapping of microsatellite markers around the arcelin bruchid resistance locus in common bean.

    PubMed

    Blair, Matthew W; Muñoz, Claritza; Buendía, Héctor F; Flower, José; Bueno, Juan M; Cardona, César

    2010-07-01

    The deployment in common beans (Phaseolus vulgaris L.) of arcelin-based bruchid resistance could help reduce post-harvest storage losses to the Mexican bean weevil [(Zabrotes subfasciatus (Boheman)]. Arcelin is a member of the arcelin-phytohemagglutinin-alpha-amylase inhibitor (APA) family of seed proteins, which has been extensively studied but not widely used in bean breeding programs. The purpose of this study was to evaluate microsatellite markers for genetic analysis of arcelin-based bruchid resistance and to determine the orientation of markers and the rate of recombination around the APA locus. A total of 10 previously developed microsatellites and 22 newly developed markers based on a sequenced BAC from the APA locus were screened for polymorphism and of these 15 were mapped with an F(2) population of 157 individuals resulting from a susceptible x resistant cross of SEQ1006 x RAZ106 that segregated for both the arcelin 1 allele and resistance to the bruchid, Z. subfasciatus. Microsatellites derived from APA gene sequences were linked within 0.8 cM of each other and were placed relative to the rest of the b04 linkage group. In a comparison of genetic to physical distance on the BAC sequence, recombination was found to be moderate with a ratio of 125 kb/cM, but repressed within the APA locus itself. Several markers were predicted to be very effective for genetic studies or marker-assisted selection, based on their significant associations with bruchid resistance and on low adult insect emergence and positions flanking the arcelin and phytohemagglutinin genes. PMID:20358173

  17. Genetic and molecular characterization of the maize rp3 rust resistance locus.

    PubMed Central

    Webb, Craig A; Richter, Todd E; Collins, Nicholas C; Nicolas, Marie; Trick, Harold N; Pryor, Tony; Hulbert, Scot H

    2002-01-01

    In maize, the Rp3 gene confers resistance to common rust caused by Puccinia sorghi. Flanking marker analysis of rust-susceptible rp3 variants suggested that most of them arose via unequal crossing over, indicating that rp3 is a complex locus like rp1. The PIC13 probe identifies a nucleotide binding site-leucine-rich repeat (NBS-LRR) gene family that maps to the complex. Rp3 variants show losses of PIC13 family members relative to the resistant parents when probed with PIC13, indicating that the Rp3 gene is a member of this family. Gel blots and sequence analysis suggest that at least 9 family members are at the locus in most Rp3-carrying lines and that at least 5 of these are transcribed in the Rp3-A haplotype. The coding regions of 14 family members, isolated from three different Rp3-carrying haplotypes, had DNA sequence identities from 93 to 99%. Partial sequencing of clones of a BAC contig spanning the rp3 locus in the maize inbred line B73 identified five different PIC13 paralogues in a region of approximately 140 kb. PMID:12242248

  18. Genetic and molecular characterization of the maize rp3 rust resistance locus.

    PubMed

    Webb, Craig A; Richter, Todd E; Collins, Nicholas C; Nicolas, Marie; Trick, Harold N; Pryor, Tony; Hulbert, Scot H

    2002-09-01

    In maize, the Rp3 gene confers resistance to common rust caused by Puccinia sorghi. Flanking marker analysis of rust-susceptible rp3 variants suggested that most of them arose via unequal crossing over, indicating that rp3 is a complex locus like rp1. The PIC13 probe identifies a nucleotide binding site-leucine-rich repeat (NBS-LRR) gene family that maps to the complex. Rp3 variants show losses of PIC13 family members relative to the resistant parents when probed with PIC13, indicating that the Rp3 gene is a member of this family. Gel blots and sequence analysis suggest that at least 9 family members are at the locus in most Rp3-carrying lines and that at least 5 of these are transcribed in the Rp3-A haplotype. The coding regions of 14 family members, isolated from three different Rp3-carrying haplotypes, had DNA sequence identities from 93 to 99%. Partial sequencing of clones of a BAC contig spanning the rp3 locus in the maize inbred line B73 identified five different PIC13 paralogues in a region of approximately 140 kb. PMID:12242248

  19. Rpv10: a new locus from the Asian Vitis gene pool for pyramiding downy mildew resistance loci in grapevine.

    PubMed

    Schwander, Florian; Eibach, Rudolf; Fechter, Iris; Hausmann, Ludger; Zyprian, Eva; Töpfer, Reinhard

    2012-01-01

    A population derived from a cross between grapevine breeding strain Gf.Ga-52-42 and cultivar 'Solaris' consisting of 265 F1-individuals was genetically mapped using SSR markers and screened for downy mildew resistance. Quantitative trait locus (QTL) analysis revealed two strong QTLs on linkage groups (LGs) 18 and 09. The locus on LG 18 was found to be identical with the previously described locus Rpv3 and is transmitted by Gf.Ga-52-42. 'Solaris' transmitted the resistance-related locus on LG 09 explaining up to 50% of the phenotypic variation in the population. This downy mildew resistance locus is named Rpv10 for resistance to Plasmopara viticola. Rpv10 was initially introgressed from Vitis amurensis, a wild species of the Asian Vitis gene pool. The one-LOD supported confidence interval of the QTL spans a section of 2.1 centi Morgan (cM) corresponding to 314 kb in the reference genome PN40024 (12x). Eight resistance gene analogues (RGAs) of the NBS-LRR type and additional resistance-linked genes are located in this region of PN40024. The F1 sub-population which contains the Rpv3 as well as the Rpv10 locus showed a significantly higher degree of resistance, indicating additive effects by pyramiding of resistance loci. Possibilities for using the resistance locus Rpv10 in a grapevine breeding programme are discussed. Furthermore, the marker data revealed 'Severnyi' × 'Muscat Ottonel' as the true parentage for the male parent of 'Solaris'. PMID:21935694

  20. Multiple antibiotic resistance (mar) locus in Salmonella enterica serovar typhimurium DT104.

    PubMed

    Randall, L P; Woodward, M J

    2001-03-01

    In order to understand the role of the mar locus in Salmonella with regard to multiple antibiotic resistance, cyclohexane resistance, and outer membrane protein F (OmpF) regulation, a marA::gfp reporter mutant was constructed in an antibiotic-sensitive Salmonella enterica serovar Typhimurium DT104 background. Salicylate induced marA, whereas a number of antibiotics, disinfectants, and various growth conditions did not. Increased antibiotic resistance was observed upon salicylate induction, although this was shown to be by both mar-dependent and mar-independent pathways. Cyclohexane resistance, however, was induced by salicylate by a mar-dependent pathway. Complementation studies with a plasmid that constitutively expressed marA confirmed the involvement of mar in Salmonella with low-level antibiotic resistance and cyclohexane resistance, although the involvement of mar in down regulation of OmpF was unclear. However, marA overexpression did increase the expression of a ca. 50-kDa protein, but its identity remains to be elucidated. Passage of the marA::gfp reporter mutant with increasing levels of tetracycline, a method reported to select for mar mutants in Escherichia coli, led to both multiple-antibiotic and cyclohexane resistance. Collectively, these data indicate that low-level antibiotic resistance, cyclohexane resistance, and modulation of OMPs in Salmonella, as in E. coli, can occur in both a mar-dependent and mar-independent manner. PMID:11229910

  1. A mutagenesis-derived broad-spectrum disease resistance locus in wheat.

    PubMed

    Campbell, Jackie; Zhang, Hongtao; Giroux, Michael J; Feiz, Leila; Jin, Yue; Wang, Meinan; Chen, Xianming; Huang, Li

    2012-07-01

    Wheat leaf rust, stem rust, stripe rust, and powdery mildew caused by the fungal pathogens Puccinia triticina, P. graminis f. sp. tritici, P. striiformis f. sp. tritici, and Blumeria graminis f. sp. tritici, respectively, are destructive diseases of wheat worldwide. Breeding durable disease resistance cultivars rely largely on continually introgressing new resistance genes, especially the genes with different defense mechanisms, into adapted varieties. Here, we describe a new resistance gene obtained by mutagenesis. The mutant, MNR220 (mutagenesis-derived new resistance), enhances resistance to three rusts and powdery mildew, with the characteristics of delayed disease development at the seedling stage and completed resistance at the adult plant stage. Genetic analysis demonstrated that the resistance in MNR220 is conferred by a single semidominant gene mapped on the short arm of chromosome 2B. Gene expression profiling of several pathogenesis-related genes indicated that MNR220 has an elevated and rapid pathogen-induced response. In addition to its potential use in breeding for resistance to multiple diseases, high-resolution mapping and cloning of the disease resistance locus in MNR220 may lead to a better understanding of the regulation of defense responses in wheat. PMID:22446929

  2. Allelic and haplotypic diversity at the rp1 rust resistance locus of maize.

    PubMed Central

    Smith, Shavannor M; Pryor, Anthony J; Hulbert, Scot H

    2004-01-01

    The maize Rp1 rust resistance locus is a complex consisting of a family of closely related resistance genes. The number of Rp1 paralogs in different maize lines (haplotypes) varied from a single gene in some stocks of the inbred A188 to >50 genes in haplotypes carrying the Rp1-A and Rp1-H specificities. The sequences of paralogs in unrelated haplotypes differ, indicating that the genetic diversity of Rp1-related genes is extremely broad in maize. Two unrelated haplotypes with five or nine paralogs had identical resistance phenotypes (Rp1-D) encoded in genes that differed by three nucleotides resulting in a single amino acid substitution. Genes in some haplotypes are more similar to each other than to any of the genes in other haplotypes indicating that they are evolving in a concerted fashion. PMID:15342531

  3. Locus-specific genetic differentiation at Rw among warfarin-resistant rat (Rattus norvegicus) populations.

    PubMed Central

    Kohn, Michael H; Pelz, Hans-Joachim; Wayne, Robert K

    2003-01-01

    Populations may diverge at fitness-related genes as a result of adaptation to local conditions. The ability to detect this divergence by marker-based genomic scans depends on the relative magnitudes of selection, recombination, and migration. We survey rat (Rattus norvegicus) populations to assess the effect that local selection with anticoagulant rodenticides has had on microsatellite marker variation and differentiation at the warfarin resistance gene (Rw) relative to the effect on the genomic background. Initially, using a small sample of 16 rats, we demonstrate tight linkage of microsatellite D1Rat219 to Rw by association mapping of genotypes expressing an anticoagulant-rodenticide-insensitive vitamin K 2,3-epoxide reductase (VKOR). Then, using allele frequencies at D1Rat219, we show that predicted and observed resistance levels in 27 populations correspond, suggesting intense and recent selection for resistance. A contrast of F(ST) values between D1Rat219 and the genomic background revealed that rodenticide selection has overwhelmed drift-mediated population structure only at Rw. A case-controlled design distinguished these locus-specific effects of selection at Rw from background levels of differentiation more effectively than a population-controlled approach. Our results support the notion that an analysis of locus-specific population genetic structure may assist the discovery and mapping of novel candidate loci that are the object of selection or may provide supporting evidence for previously identified loci. PMID:12871915

  4. Development and validation of a breeder-friendly KASPar marker for wheat leaf rust resistance locus Lr21

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Development and utilization of genetic markers play a pivotal role in marker assisted breeding of wheat cultivars with pyramids of disease resistance genes. The objective of this study is to develop a closed tube, gel-free assay for high throughput genotyping of leaf rust resistance locus Lr21. Poly...

  5. Mining Disease-Resistance Genes in Roses: Functional and Molecular Characterization of the Rdr1 Locus

    PubMed Central

    Terefe-Ayana, Diro; Yasmin, Aneela; Le, Thanh Loan; Kaufmann, Helgard; Biber, Anja; Kühr, Astrid; Linde, Marcus; Debener, Thomas

    2011-01-01

    The interaction of roses with the leaf spot pathogen Diplocarpon rosae (the cause of black spot on roses) is an interesting pathosystem because it involves a long-lived woody perennial, with life history traits very different from most model plants, and a hemibiotrophic pathogen with moderate levels of gene flow. Here we present data on the molecular structure of the first monogenic dominant resistance gene from roses, Rdr1, directed against one isolate of D. rosae. Complete sequencing of the locus carrying the Rdr1 gene resulted in a sequence of 265,477 bp with a cluster of nine highly related TIR–NBS–LRR (TNL) candidate genes. After sequencing revealed candidate genes for Rdr1, we implemented a gene expression analysis and selected five genes out of the nine TNLs. We then silenced the whole TNL gene family using RNAi (Rdr1–RNAi) constructed from the most conserved sequence region and demonstrated a loss of resistance in the normally resistant genotype. To identify the functional TNL gene, we further screened the five TNL candidate genes with a transient leaf infiltration assay. The transient expression assay indicated a single TNL gene (muRdr1H), partially restoring resistance in the susceptible genotype. Rdr1 was found to localize within the muRdr1 gene family; the genes within this locus contain characteristic motifs of active TNL genes and belong to a young cluster of R genes. The transient leaf assay can be used to further analyze the rose black spot interaction and its evolution, extending the analyses to additional R genes and to additional pathogenic types of the pathogen. PMID:22639591

  6. Genetic Polymorphism of agr Locus and Antibiotic Resistance of Staphylococcus aureus at two hospitals in Pakistan

    PubMed Central

    Khan, Sadia; Rasheed, Faisal; Zahra, Rabaab

    2014-01-01

    Objective: The accessory gene regulator (agr) locus in Staphylococcus aureus (S. aureus) is a global regulator of quorum sensing and controls the production of virulence factors. This study was carried out to investigate the agr specific groups both in methicillin resistant and sensitive Staphylococcus aureus (MRSA and MSSA) and their relation with antibiotic resistance. Methods: A total of 90 clinical S. aureus isolates were studied from two tertiary care hospitals. The isolates were identified by standard biochemical tests. Methicillin resistance was confirmed by oxacillin and cefoxitin resistance. Multiplex PCR was used to determine the agr groups. Results: MRSA prevalence was found to be 53.3%.The agr groups’ distribution in MRSA was as follows: 22 (45.8%) belonged to group I, 14 (29.1%) belonged to group III and 2 (4.1%) belonged to group II. agrIV was not detected in MRSA. For 17 isolates, the agr group was not detected.agr III isolates showed higher antibiotic resistance than agrI isolates except in case of oxacillin and linezolid. Conclusions: Strict infection control policy and antibiotic guidelines should be adopted to control the problem of MRSA. Higher prevalence of agr I and agr III shows that they are dominant agr groups of our area. PMID:24639855

  7. Artemisinin Resistance-Associated Polymorphisms at the K13-Propeller Locus Are Absent in Plasmodium falciparum Isolates from Haiti

    PubMed Central

    Carter, Tamar E.; Boulter, Alexis; Existe, Alexandre; Romain, Jean R.; St. Victor, Jean Yves; Mulligan, Connie J.; Okech, Bernard A.

    2015-01-01

    Antimalarial drugs are a key tool in malaria elimination programs. With the emergence of artemisinin resistance in southeast Asia, an effort to identify molecular markers for surveillance of resistant malaria parasites is underway. Non-synonymous mutations in the kelch propeller domain (K13-propeller) in Plasmodium falciparum have been associated with artemisinin resistance in samples from southeast Asia, but additional studies are needed to characterize this locus in other P. falciparum populations with different levels of artemisinin use. Here, we sequenced the K13-propeller locus in 82 samples from Haiti, where limited government oversight of non-governmental organizations may have resulted in low-level use of artemisinin-based combination therapies. We detected a single-nucleotide polymorphism (SNP) at nucleotide 1,359 in a single isolate. Our results contribute to our understanding of the global genomic diversity of the K13-propeller locus in P. falciparum populations. PMID:25646258

  8. Artemisinin resistance-associated polymorphisms at the K13-propeller locus are absent in Plasmodium falciparum isolates from Haiti.

    PubMed

    Carter, Tamar E; Boulter, Alexis; Existe, Alexandre; Romain, Jean R; St Victor, Jean Yves; Mulligan, Connie J; Okech, Bernard A

    2015-03-01

    Antimalarial drugs are a key tool in malaria elimination programs. With the emergence of artemisinin resistance in southeast Asia, an effort to identify molecular markers for surveillance of resistant malaria parasites is underway. Non-synonymous mutations in the kelch propeller domain (K13-propeller) in Plasmodium falciparum have been associated with artemisinin resistance in samples from southeast Asia, but additional studies are needed to characterize this locus in other P. falciparum populations with different levels of artemisinin use. Here, we sequenced the K13-propeller locus in 82 samples from Haiti, where limited government oversight of non-governmental organizations may have resulted in low-level use of artemisinin-based combination therapies. We detected a single-nucleotide polymorphism (SNP) at nucleotide 1,359 in a single isolate. Our results contribute to our understanding of the global genomic diversity of the K13-propeller locus in P. falciparum populations. PMID:25646258

  9. Recombination suppression at the dominant Rhg1/Rfs2 locus underlying soybean resistance to the cyst nematode.

    PubMed

    Afzal, Ahmed J; Srour, Ali; Saini, Navinder; Hemmati, Naghmeh; El Shemy, Hany A; Lightfoot, David A

    2012-04-01

    Host resistance to "yellow dwarf" or "moonlight" disease cause by any population (Hg type) of Heterodera glycines I., the soybean cyst nematode (SCN), requires a functional allele at rhg1. The host resistance encoded appears to mimic an apoptotic response in the giant cells formed at the nematode feeding site about 24-48 h after nematode feeding commences. Little is known about how the host response to infection is mediated but a linked set of 3 genes has been identified within the rhg1 locus. This study aimed to identify the role of the genes within the locus that includes a receptor-like kinase (RLK), a laccase and an ion antiporter. Used were near isogeneic lines (NILs) that contrasted at their rhg1 alleles, gene-based markers, and a new Hg type 0 and new recombination events. A syntenic gene cluster on Lg B1 was found. The effectiveness of SNP probes from the RLK for distinguishing homolog sequence variants on LgB1 from alleles at the rhg1 locus on LgG was shown. The resistant allele of the rhg1 locus was shown to be dominant in NILs. None of the recombination events were within the cluster of the three candidate genes. Finally, rhg1 was shown to reduce the plant root development. A model for rhg1 as a dominant multi-gene resistance locus based on the developmental control was inferred. PMID:22200919

  10. Resistance to Puccinia graminis f. sp. avenae in Barley Is Associated with the Rpg5 Locus.

    PubMed

    Dracatos, Peter; Singh, Davinder; Fetch, Tom; Park, Robert

    2015-04-01

    In barley, gene Rpg5 was first identified for providing resistance to the rye stem rust pathogen (Puccinia graminis f. sp. secalis). A subsequent study determined that Rpg5 is required for rpg4-mediated resistance to the wheat stem rust pathogen (P. graminis f. sp. tritici) including pathotype TTKSK ("Ug99"), which poses a major threat to global wheat and barley production. Based on the effectiveness of Rpg5 against P. graminis f. sp. tritici and P. graminis f. sp. secalis, we assessed whether it also conferred resistance to the oat stem rust pathogen (P. graminis f. sp. avenae). A barley F8 recombinant inbred line (RIL) population was produced by crossing 'Q21861' (Rpg1 and Rpg5) with '73-G1' (Rpg1), which is susceptible to P. graminis f. sp. avenae, P. graminis f. sp. secalis, and some pathotypes of P. graminis f. sp. tritici. Seedling tests were performed on the F8 RIL population using Australian pathotypes of P. graminis f. sp. tritici, P. graminis f. sp. secalis, P. graminis f. sp. avenae, and a putative somatic hybrid between P. graminis f. sp. tritici and P. graminis f. sp. secalis known as the 'Scabrum' rust. Segregation in the responses to all rust isolates for the RILs was identical (50 resistant: 52 susceptible), and fitted a 1:1 ratio (X2=0.039, P=0.843), indicating that resistance to all isolates was monogenetically inherited. Screening of the RILs and the parental lines with perfect markers for the functional Rpg1 and Rpg5 resistance alleles indicated that Rpg1 was fixed, while Rpg5 was positive in all resistant lines and negative in all susceptible lines. This suggests that different formae speciales of P. graminis may share common effectors, and that the Rpg5 locus confers resistance to both P. graminis f. sp. tritici and P. graminis f. sp. secalis and the heterologous formae speciales of P. graminis, P. graminis f. sp. avenae. PMID:25870923

  11. Unraveling Genomic Complexity at a Quantitative Disease Resistance Locus in Maize

    PubMed Central

    Jamann, Tiffany M.; Poland, Jesse A.; Kolkman, Judith M.; Smith, Laurie G.; Nelson, Rebecca J.

    2014-01-01

    Multiple disease resistance has important implications for plant fitness, given the selection pressure that many pathogens exert directly on natural plant populations and indirectly via crop improvement programs. Evidence of a locus conditioning resistance to multiple pathogens was found in bin 1.06 of the maize genome with the allele from inbred line “Tx303” conditioning quantitative resistance to northern leaf blight (NLB) and qualitative resistance to Stewart’s wilt. To dissect the genetic basis of resistance in this region and to refine candidate gene hypotheses, we mapped resistance to the two diseases. Both resistance phenotypes were localized to overlapping regions, with the Stewart’s wilt interval refined to a 95.9-kb segment containing three genes and the NLB interval to a 3.60-Mb segment containing 117 genes. Regions of the introgression showed little to no recombination, suggesting structural differences between the inbred lines Tx303 and “B73,” the parents of the fine-mapping population. We examined copy number variation across the region using next-generation sequencing data, and found large variation in read depth in Tx303 across the region relative to the reference genome of B73. In the fine-mapping region, association mapping for NLB implicated candidate genes, including a putative zinc finger and pan1. We tested mutant alleles and found that pan1 is a susceptibility gene for NLB and Stewart’s wilt. Our data strongly suggest that structural variation plays an important role in resistance conditioned by this region, and pan1, a gene conditioning susceptibility for NLB, may underlie the QTL. PMID:25009146

  12. Transcriptome and Allele Specificity Associated with a 3BL Locus for Fusarium Crown Rot Resistance in Bread Wheat

    PubMed Central

    Ma, Jian; Stiller, Jiri; Zhao, Qiang; Feng, Qi; Cavanagh, Colin; Wang, Penghao; Gardiner, Donald; Choulet, Frédéric; Feuillet, Catherine; Zheng, You-Liang; Wei, Yuming; Yan, Guijun; Han, Bin; Manners, John M.; Liu, Chunji

    2014-01-01

    Fusarium pathogens cause two major diseases in cereals, Fusarium crown rot (FCR) and head blight (FHB). A large-effect locus conferring resistance to FCR disease was previously located to chromosome arm 3BL (designated as Qcrs-3B) and several independent sets of near isogenic lines (NILs) have been developed for this locus. In this study, five sets of the NILs were used to examine transcriptional changes associated with the Qcrs-3B locus and to identify genes linked to the resistance locus as a step towards the isolation of the causative gene(s). Of the differentially expressed genes (DEGs) detected between the NILs, 12.7% was located on the single chromosome 3B. Of the expressed genes containing SNP (SNP-EGs) detected, 23.5% was mapped to this chromosome. Several of the DEGs and SNP-EGs are known to be involved in host-pathogen interactions, and a large number of the DEGs were among those detected for FHB in previous studies. Of the DEGs detected, 22 were mapped in the Qcrs-3B interval and they included eight which were detected in the resistant isolines only. The enrichment of DEG, and not necessarily those containing SNPs between the resistant and susceptible isolines, around the Qcrs-3B locus is suggestive of local regulation of this region by the resistance allele. Functions for 13 of these DEGs are known. Of the SNP-EGs, 28 were mapped in the Qcrs-3B interval and biological functions for 16 of them are known. These results provide insights into responses regulated by the 3BL locus and identify a tractable number of target genes for fine mapping and functional testing to identify the causative gene(s) at this QTL. PMID:25405461

  13. Transcriptome and allele specificity associated with a 3BL locus for Fusarium crown rot resistance in bread wheat.

    PubMed

    Ma, Jian; Stiller, Jiri; Zhao, Qiang; Feng, Qi; Cavanagh, Colin; Wang, Penghao; Gardiner, Donald; Choulet, Frédéric; Feuillet, Catherine; Zheng, You-Liang; Wei, Yuming; Yan, Guijun; Han, Bin; Manners, John M; Liu, Chunji

    2014-01-01

    Fusarium pathogens cause two major diseases in cereals, Fusarium crown rot (FCR) and head blight (FHB). A large-effect locus conferring resistance to FCR disease was previously located to chromosome arm 3BL (designated as Qcrs-3B) and several independent sets of near isogenic lines (NILs) have been developed for this locus. In this study, five sets of the NILs were used to examine transcriptional changes associated with the Qcrs-3B locus and to identify genes linked to the resistance locus as a step towards the isolation of the causative gene(s). Of the differentially expressed genes (DEGs) detected between the NILs, 12.7% was located on the single chromosome 3B. Of the expressed genes containing SNP (SNP-EGs) detected, 23.5% was mapped to this chromosome. Several of the DEGs and SNP-EGs are known to be involved in host-pathogen interactions, and a large number of the DEGs were among those detected for FHB in previous studies. Of the DEGs detected, 22 were mapped in the Qcrs-3B interval and they included eight which were detected in the resistant isolines only. The enrichment of DEG, and not necessarily those containing SNPs between the resistant and susceptible isolines, around the Qcrs-3B locus is suggestive of local regulation of this region by the resistance allele. Functions for 13 of these DEGs are known. Of the SNP-EGs, 28 were mapped in the Qcrs-3B interval and biological functions for 16 of them are known. These results provide insights into responses regulated by the 3BL locus and identify a tractable number of target genes for fine mapping and functional testing to identify the causative gene(s) at this QTL. PMID:25405461

  14. Identification of a New Locus, Ptr(t), Required for Rice Blast Resistance Gene Pi-ta-Mediated Resistance

    SciTech Connect

    Jia, Yulin; Martin, Rodger Carl

    2008-01-01

    Resistance to the blast pathogen Magnaporthe oryzae is proposed to be initiated by physical binding of a putative cytoplasmic receptor encoded by a NBS type resistance gene Pi-ta to the processed elicitor encoded by the corresponding avirulence gene AVR-Pita. Here we report the identification of a new locus Ptr(t) that is required for Pi-ta-mediated signal recognition. A Pi-ta expressing susceptible mutant was identified using a genetic screen. Putative mutations at Ptr(t) does not alter recognition specificity to another resistance gene Pi-ks in the Pi-ta homozygote indicate that Ptr(t) is more likely specific to Pi-ta-mediated signal recognition. Genetic crosses of Pi-ta Ptr(t) and Pi-ta ptr(t) homozygotes suggest that Ptr(t) segregate at single dominant nuclear gene. A ratio of 1 resistant: 1 susceptible of a BC1 using Pi-ta Ptr(t) with pi-ta ptr(t) homozygotes indicates that Pi-ta and Ptr(t) are linked and co-segregated. Genotyping of mutants of pi-ta ptr(t) and Pi-ta Ptr(t) homozygotes using ten simple sequence repeat markers spanning 9 megabase of Pi-ta determines that Pi-ta and Ptr(t) are of indica origin. Identification of Ptr(t) is a significant advancement in studying Pi-ta-mediated signal recognition and transduction.

  15. Three-dimensional modeling and diversity analysis reveals distinct AVR recognition sites and evolutionary pathways in wild and domesticated wheat Pm3 R genes.

    PubMed

    Sela, Hanan; Spiridon, Laurentiu N; Ashkenazi, Haim; Bhullar, Navreet K; Brunner, Susanne; Petrescu, Andrei-Jose; Fahima, Tzion; Keller, Beat; Jordan, Tina

    2014-08-01

    The Pm3 gene confers resistance against wheat powdery mildew. Studies of Pm3 diversity have shown that Pm3 alleles isolated from southern populations of wild emmer wheat located in Lebanon, Jordan, Israel, and Syria are more diverse and more distant from bread wheat alleles than alleles from the northern wild wheat populations located in Turkey, Iran, and Iraq. Therefore, southern populations from Israel were studied extensively to reveal novel Pm3 alleles that are absent from the cultivated gene pool. Candidate Pm3 genes were isolated via a polymerase chain reaction cloning approach. Known and newly identified Pm3 genes were subjected to variation analysis and polymorphic amino acid residues were superimposed on a three-dimensional (3D) model of PM3. The region of highest interspecies diversity between Triticum aestivum and T. dicoccoides lies in leucine-rich repeats (LRR) 19 to 24, whereas most intraspecies diversity in T. aestivum is located in LRR 25 to 28. Interestingly, these two regions are separated by one large LRR whose propensity for flexibility facilitates the conformation of the PM3 LRR domain into two differently structured models. The combination of evolutionary and protein 3D structure analysis revealed that Pm3 genes in wild and domesticated wheat show different evolutionary histories which might have been triggered through different interactions with the powdery mildew pathogen. PMID:24742072

  16. A novel locus of resistance to severe malaria in a region of ancient balancing selection.

    PubMed

    Band, Gavin; Rockett, Kirk A; Spencer, Chris C A; Kwiatkowski, Dominic P

    2015-10-01

    The high prevalence of sickle haemoglobin in Africa shows that malaria has been a major force for human evolutionary selection, but surprisingly few other polymorphisms have been proven to confer resistance to malaria in large epidemiological studies. To address this problem, we conducted a multi-centre genome-wide association study (GWAS) of life-threatening Plasmodium falciparum infection (severe malaria) in over 11,000 African children, with replication data in a further 14,000 individuals. Here we report a novel malaria resistance locus close to a cluster of genes encoding glycophorins that are receptors for erythrocyte invasion by P. falciparum. We identify a haplotype at this locus that provides 33% protection against severe malaria (odds ratio = 0.67, 95% confidence interval = 0.60-0.76, P value = 9.5 × 10(-11)) and is linked to polymorphisms that have previously been shown to have features of ancient balancing selection, on the basis of haplotype sharing between humans and chimpanzees. Taken together with previous observations on the malaria-protective role of blood group O, these data reveal that two of the strongest GWAS signals for severe malaria lie in or close to genes encoding the glycosylated surface coat of the erythrocyte cell membrane, both within regions of the genome where it appears that evolution has maintained diversity for millions of years. These findings provide new insights into the host-parasite interactions that are critical in determining the outcome of malaria infection. PMID:26416757

  17. Recombination between paralogues at the Rp1 rust resistance locus in maize.

    PubMed Central

    Sun, Q; Collins, N C; Ayliffe, M; Smith, S M; Drake, J; Pryor, T; Hulbert, S H

    2001-01-01

    Rp1 is a complex rust resistance locus of maize. The HRp1-D haplotype is composed of Rp1-D and eight paralogues, seven of which also code for predicted nucleotide binding site-leucine rich repeat (NBS-LRR) proteins similar to the Rp1-D gene. The paralogues are polymorphic (DNA identities 91-97%), especially in the C-terminal LRR domain. The remaining family member encodes a truncated protein that has no LRR domain. Seven of the nine family members, including the truncated gene, are transcribed. Sequence comparisons between paralogues provide evidence for past recombination events between paralogues and diversifying selection, particularly in the C-terminal half of the LRR domain. Variants selected for complete or partial loss of Rp1-D resistance can be explained by unequal crossing over that occurred mostly within coding regions. The Rp1-D gene is altered or lost in all variants, the recombination breakpoints occur throughout the genes, and most recombinant events (9/14 examined) involved the same untranscribed paralogue with the Rp1-D gene. One recombinant with a complete LRR from Rp1-D, but the amino-terminal portion from another homologue, conferred the Rp1-D specificity but with a reduced level of resistance. PMID:11333250

  18. Distinct copy number, coding sequence and locus methylation patterns underlie Rhg1-mediated soybean resistance to soybean cyst nematode

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Copy number variation of kilobase-scale genomic DNA segments, beyond presence/absence polymorphisms, can be an important driver of adaptive traits. Rhg1 is a widely utilized quantitative trait locus that makes the strongest known contribution to resistance against soybean cyst nematode (SCN; Hetero...

  19. On the Locus Formed by the Maximum Heights of Projectile Motion with Air Resistance

    ERIC Educational Resources Information Center

    Hernandez-Saldana, H.

    2010-01-01

    We present an analysis on the locus formed by the set of maxima of the trajectories of a projectile launched in a medium with linear drag. Such a place, the locus of apexes, is written in terms of the Lambert "W" function in polar coordinates, confirming the special role played by this function in the problem. To characterize the locus, a study of…

  20. Cloning and characterization of XiR1, a locus responsible for dagger nematode resistance in grape

    PubMed Central

    Hwang, Chin-Feng; Xu, Kenong; Hu, Rong; Zhou, Rita; Riaz, Summaira

    2010-01-01

    The dagger nematode, Xiphinemaindex, feeds aggressively on grape roots and in the process, vectors grapevine fanleaf virus (GFLV) leading to the severe viral disease known as fanleaf degeneration. Resistance to X. index and GFLV has been the key objective of grape rootstock breeding programs. A previous study found that resistance to X. index derived from Vitis arizonica was largely controlled by a major quantitative trait locus, XiR1 (X. index Resistance 1), located on chromosome 19. The study presented here develops high-resolution genetic and physical maps in an effort to identify the XiR1 gene(s). The mapping was carried out with 1,375 genotypes in three populations derived from D8909-15, a resistant selection from a cross of V. rupestris A. de Serres (susceptible) × V. arizonica b42-26 (resistant). Resistance to X. index was evaluated on 99 informative recombinants that were identified by screening the three populations with two markers flanking the XiR1 locus. The high-resolution genetic map of XiR1 was primarily constructed with seven DNA markers developed in this study. Physical mapping of XiR1 was accomplished by screening three bacterial artificial chromosome (BAC) libraries constructed from D8909-15, V. vinifera Cabernet Sauvignon and V. arizonica b42-26. A total of 32 BAC clones were identified and the XiR1 locus was delineated within a 115 kb region. Sequence analysis of three BAC clones identified putative nucleotide binding/leucine-rich repeat (NB-LRR) genes. This is the first report of a closely linked major gene locus responsible for ectoparasitic nematode resistance. The markers developed from this study are being used to expedite the breeding of resistant grape rootstocks. PMID:20490447

  1. Identification of a new locus, Ptr(t), required for rice blast resistance gene Pi-ta-mediated resistance.

    PubMed

    Jia, Yulin; Martin, Rodger

    2008-04-01

    Resistance to the blast pathogen Magnaporthe oryzae is proposed to be initiated by physical binding of a putative cytoplasmic receptor encoded by a nucleotide binding site-type resistance gene, Pi-ta, to the processed elicitor encoded by the corresponding avirulence gene AVR-Pita. Here, we report the identification of a new locus, Ptr(t), that is required for Pi-ta-mediated signal recognition. A Pi-ta-expressing susceptible mutant was identified using a genetic screen. Putative mutations at Ptr(t) do not alter recognition specificity to another resistance gene, Pi-k(s), in the Pi-ta homozygote, indicating that Ptr(t) is more likely specific to Pi-ta-mediated signal recognition. Genetic crosses of Pi-ta Ptr(t) and Pi-ta ptr(t) homozygotes suggest that Ptr(t) segregates as a single dominant nuclear gene. A ratio of 1:1 (resistant/susceptible) of a population of BC1 of Pi-ta Ptr(t) with pi-ta ptr(t) homozygotes indicates that Pi-ta and Ptr(t) are linked and cosegregate. Genotyping of mutants of pi-ta ptr(t) and Pi-ta Ptr(t) homozygotes using ten simple sequence repeat markers at the Pi-ta region determined that Pi-ta and Ptr(t) are located within a 9-megabase region and are of indica origin. Identification of Ptr(t) is a significant advancement in studying Pi-ta-mediated signal recognition and transduction. PMID:18321185

  2. A Locus at 5q33.3 Confers Resistance to Tuberculosis in Highly Susceptible Individuals.

    PubMed

    Sobota, Rafal S; Stein, Catherine M; Kodaman, Nuri; Scheinfeldt, Laura B; Maro, Isaac; Wieland-Alter, Wendy; Igo, Robert P; Magohe, Albert; Malone, LaShaunda L; Chervenak, Keith; Hall, Noemi B; Modongo, Chawangwa; Zetola, Nicola; Matee, Mecky; Joloba, Moses; Froment, Alain; Nyambo, Thomas B; Moore, Jason H; Scott, William K; Lahey, Timothy; Boom, W Henry; von Reyn, C Fordham; Tishkoff, Sarah A; Sirugo, Giorgio; Williams, Scott M

    2016-03-01

    Immunosuppression resulting from HIV infection increases the risk of progression to active tuberculosis (TB) both in individuals newly exposed to Mycobacterium tuberculosis (MTB) and in those with latent infections. We hypothesized that HIV-positive individuals who do not develop TB, despite living in areas where it is hyperendemic, provide a model of natural resistance. We performed a genome-wide association study of TB resistance by using 581 HIV-positive Ugandans and Tanzanians enrolled in prospective cohort studies of TB; 267 of these individuals developed active TB, and 314 did not. A common variant, rs4921437 at 5q33.3, was significantly associated with TB (odds ratio = 0.37, p = 2.11 × 10(-8)). This variant lies within a genomic region that includes IL12B and is embedded in an H3K27Ac histone mark. The locus also displays consistent patterns of linkage disequilibrium across African populations and has signals of strong selection in populations from equatorial Africa. Along with prior studies demonstrating that therapy with IL-12 (the cytokine encoded in part by IL12B, associated with longer survival following MTB infection in mice deficient in CD4 T cells), our results suggest that this pathway might be an excellent target for the development of new modalities for treating TB, especially for HIV-positive individuals. Our results also indicate that studying extreme disease resistance in the face of extensive exposure can increase the power to detect associations in complex infectious disease. PMID:26942285

  3. Genetic analyses of the major and minor locus groups of bacterial wilt resistance in tobacco using a diallel cross design.

    PubMed

    Qian, Y L; Chen, J; Dong, J J; Wu, Z C; Liu, Y H; Xue, B Y; Shao, F W; Sun, X Y

    2016-01-01

    Tobacco germplasm samples with various levels of resistance to bacterial wilt were selected to construct F1 combinations of parental inbred lines and orthogonal diallel crosses using samples collected in 2009 (15 germplasms), 2010 (15 germplasms), and 2011 (16 germplasms). A total of 1/2P (P + 1) experimental materials were used for analysis. Based on the analyses of major and minor locus groups, genetic effects on the incidence rate and index of bacterial wilt in tobacco were investigated on the 15th and 25th day during the early stage. Significant effects were observed in major locus groups, but not in minor locus groups. Specifically, adjacent major locus groups (J1 = 13,056 and J1 = 13,055; J1 = 14,080 and J1 = 14,079) were detected in both the first and second analyses with considerable effects. Based on the additive effects of minor locus groups on the rate and index of bacterial wilt, the effects on the incidence rates of Yunyan 85, DB101, and RG11 as well as the effects on the disease index of the latter two germplasms reached the maximum. This was consistent with the disease resistance indicators of these tobacco varieties in the field (corresponding broad heritability >20%). Genetic homozygous dominant loci (+ +) increased the rate of bacterial wilt (susceptible), whereas homozygous recessive loci (- -) reduced the index of bacterial wilt (resistant) with considerable additive effects and low dominant effects, suggesting that the inheritance of the bacterial wilt rate and index in tobacco mainly relies on additive inheritance. PMID:26909932

  4. Genome dynamics and evolution of the Mla (powdery mildew) resistance locus in barley.

    PubMed

    Wei, Fusheng; Wing, Rod A; Wise, Roger P

    2002-08-01

    Genes that confer defense against pathogens often are clustered in the genome and evolve via diverse mechanisms. To evaluate the organization and content of a major defense gene complex in cereals, we determined the complete sequence of a 261-kb BAC contig from barley cv Morex that spans the Mla (powdery mildew) resistance locus. Among the 32 predicted genes on this contig, 15 are associated with plant defense responses; 6 of these are associated with defense responses to powdery mildew disease but function in different signaling pathways. The Mla region is organized as three gene-rich islands separated by two nested complexes of transposable elements and a 45-kb gene-poor region. A heterochromatic-like region is positioned directly proximal to Mla and is composed of a gene-poor core with 17 families of diverse tandem repeats that overlap a hypermethylated, but transcriptionally active, gene-dense island. Paleontology analysis of long terminal repeat retrotransposons indicates that the present Mla region evolved over a period of >7 million years through a variety of duplication, inversion, and transposon-insertion events. Sequence-based recombination estimates indicate that R genes positioned adjacent to nested long terminal repeat retrotransposons, such as Mla, do not favor recombination as a means of diversification. We present a model for the evolution of the Mla region that encompasses several emerging features of large cereal genomes. PMID:12172030

  5. [Control locus, stress resistance and personal growth of the participants in experiment Mars-500].

    PubMed

    Solcova, I; Vinokhodova, A G

    2013-01-01

    The article deals with positive personal transformations in a simulated space mission. The investigation was focused on the aspects of control locus, stamina, proactive behavior to overcome challenges, and stress-related personal growth. Besides, ingenious psychophysiological techniques designed to select Russian cosmonauts were used for assessing stress-resistance and ability to control own emotions voluntarily. Experiment Mars-500 simulated the basic features of a mission to Mars. The crew consisted of 6 males 27 to 38 years of age who volunteered to spend 520 days in isolation and confinement in the IBMP experimental facility (Moscow). To detect personality changes, the volunteers were tested before the experiment and after its completion. According to the test results, the participants commonly demonstrated the ability to see the bright side of the Mars-500 adversities, which most often was caused by their social growth. Positive changes were particularly pronounced in the crewmembers who possessed a better ability to control own emotions. The simulated challenges were also beneficial for personal growth of the volunteers. PMID:24032161

  6. Quantitative trait locus mapping and functional genomics of an organophosphate resistance trait in the western corn rootworm, Diabrotica virgifera virgifera.

    PubMed

    Coates, B S; Alves, A P; Wang, H; Zhou, X; Nowatzki, T; Chen, H; Rangasamy, M; Robertson, H M; Whitfield, C W; Walden, K K; Kachman, S D; French, B W; Meinke, L J; Hawthorne, D; Abel, C A; Sappington, T W; Siegfried, B D; Miller, N J

    2016-02-01

    The western corn rootworm, Diabrotica virgifera virgifera, is an insect pest of corn and population suppression with chemical insecticides is an important management tool. Traits conferring organophosphate insecticide resistance have increased in frequency amongst D. v. virgifera populations, resulting in the reduced efficacy in many corn-growing regions of the USA. We used comparative functional genomic and quantitative trait locus (QTL) mapping approaches to investigate the genetic basis of D. v. virgifera resistance to the organophosphate methyl-parathion. RNA from adult methyl-parathion resistant and susceptible adults was hybridized to 8331 microarray probes. The results predicted that 11 transcripts were significantly up-regulated in resistant phenotypes, with the most significant (fold increases ≥ 2.43) being an α-esterase-like transcript. Differential expression was validated only for the α-esterase (ST020027A20C03), with 11- to 13-fold greater expression in methyl-parathion resistant adults (P < 0.05). Progeny with a segregating methyl-parathion resistance trait were obtained from a reciprocal backcross design. QTL analyses of high-throughput single nucleotide polymorphism genotype data predicted involvement of a single genome interval. These data suggest that a specific carboyxesterase may function in field-evolved corn rootworm resistance to organophosphates, even though direct linkage between the QTL and this locus could not be established. PMID:26566705

  7. Intragenic recombination and diversifying selection contribute to the evolution of downy mildew resistance at the RPP8 locus of Arabidopsis.

    PubMed Central

    McDowell, J M; Dhandaydham, M; Long, T A; Aarts, M G; Goff, S; Holub, E B; Dangl, J L

    1998-01-01

    Pathogen resistance (R) genes of the NBS-LRR class (for nucleotide binding site and leucine-rich repeat) are found in many plant species and confer resistance to a diverse spectrum of pathogens. Little is known about the mechanisms that drive NBS-LRR gene evolution in the host-pathogen arms race. We cloned the RPP8 gene (for resistance to Peronospora parasitica) and compared the structure of alleles at this locus in resistant Landsberg erecta (Ler-0) and susceptible Columbia (Col-0) accessions. RPP8-Ler encodes an NBS-LRR protein with a putative N-terminal leucine zipper and is more closely related to previously cloned R genes that confer resistance to bacterial pathogens than it is to other known RPP genes. The RPP8 haplotype in Ler-0 contains the functional RPP8-Ler gene and a nonfunctional homolog, RPH8A. In contrast, the rpp8 locus in Col-0 contains a single chimeric gene, which was likely derived from unequal crossing over between RPP8-Ler and RPH8A ancestors within a Ler-like haplotype. Sequence divergence among RPP8 family members has been accelerated by positive selection on the putative ligand binding region in the LRRs. These observations indicate that NBS-LRR molecular evolution is driven by the same mechanisms that promote rapid sequence diversification among other genes involved in non-self-recognition. PMID:9811794

  8. Are transporter genes other than the chloroquine resistance locus (pfcrt) and multidrug resistance gene (pfmdr) associated with antimalarial drug resistance?

    PubMed

    Anderson, Timothy J C; Nair, Shalini; Qin, Huang; Singlam, Sittaporn; Brockman, Alan; Paiphun, Lucy; Nosten, François

    2005-06-01

    Mu et al. (Mu, J., M. T. Ferdig, X. Feng, D. A. Joy, J. Duan, T. Furuya, G. Subramanian, L. Aravind, R. A. Cooper, J. C. Wootton, M. Xiong, and X. Z. Su, Mol. Microbiol. 49:977-989, 2003) recently reported exciting associations between nine new candidate transporter genes and in vitro resistance to chloroquine (CQ) and quinine (QN), with six of these loci showing association with CQ or QN in a southeast Asian population sample. We replicated and extended this work by examining polymorphisms in these genes and in vitro resistance to eight drugs in parasites collected from the Thailand-Burma border. To minimize problems of multiple testing, we used a two-phase study design, while to minimize problems caused by population structure, we analyzed parasite isolates collected from a single clinic. We first examined associations between genotype and drug response in 108 unique single-clone parasite isolates. We found strong associations between single nucleotide polymorphisms in pfmdr and mefloquine (MFQ), artesunate (AS), and lumefantrine (LUM) response. We also observed associations between an ABC transporter (G7) and response to QN and AS and between another ABC transporter (G49) and response to dihydro-artemisinin (DHA). We reexamined significant associations in an independent sample of 199 unique single-clone infections from the same location. The significant associations with pfmdr-1042 detected in the first survey remained. However, with the exception of the G7-artesunate association, all other associations observed with the nine new candidate transporters disappeared. We also examined linkage disequilibrium (LD) between markers and phenotypic correlations between drug responses. We found minimal LD between genes. Furthermore, we found no correlation between chloroquine and quinine responses, although we did find expected strong correlations between MFQ, QN, AS, DHA, and LUM. To conclude, we found no evidence for an association between 8/9 candidate genes and

  9. Intrachromosomal Amplification, Locus Deletion and Point Mutation in the Aquaglyceroporin AQP1 Gene in Antimony Resistant Leishmania (Viannia) guyanensis

    PubMed Central

    Monte-Neto, Rubens; Laffitte, Marie-Claude N.; Leprohon, Philippe; Reis, Priscila; Frézard, Frédéric; Ouellette, Marc

    2015-01-01

    Background Antimony resistance complicates the treatment of infections caused by the parasite Leishmania. Methodology/Principal Findings Using next generation sequencing, we sequenced the genome of four independent Leishmania guyanensis antimony-resistant (SbR) mutants and found different chromosomal alterations including aneuploidy, intrachromosomal gene amplification and gene deletion. A segment covering 30 genes on chromosome 19 was amplified intrachromosomally in three of the four mutants. The gene coding for the multidrug resistance associated protein A involved in antimony resistance was also amplified in the four mutants, most likely through chromosomal translocation. All mutants also displayed a reduced accumulation of antimony mainly due to genomic alterations at the level of the subtelomeric region of chromosome 31 harboring the gene coding for the aquaglyceroporin 1 (LgAQP1). Resistance involved the loss of LgAQP1 through subtelomeric deletions in three mutants. Interestingly, the fourth mutant harbored a single G133D point mutation in LgAQP1 whose role in resistance was functionality confirmed through drug sensitivity and antimony accumulation assays. In contrast to the Leishmania subspecies that resort to extrachromosomal amplification, the Viannia strains studied here used intrachromosomal amplification and locus deletion. Conclusions/Significance This is the first report of a naturally occurred point mutation in AQP1 in antimony resistant parasites. PMID:25679388

  10. Identification of a major Quantitative Trait Locus determining resistance to the organophosphate temephos in the dengue vector mosquito Aedes aegypti.

    PubMed

    Paiva, Marcelo H S; Lovin, Diane D; Mori, Akio; Melo-Santos, Maria A V; Severson, David W; Ayres, Constância F J

    2016-01-01

    Organophosphate insecticides (OP) have extensively been used to control mosquitoes, such as the vector Aedes aegypti. Unfortunately, OP resistance has hampered control programs worldwide. We used Quantitative Trait Locus (QTL) mapping to evaluate temephos resistance in two F1 intercross populations derived from crosses between a resistant Ae. aegypti strain (RecR) and two susceptible strains (MoyoD and Red). A single major effect QTL was identified on chromosome 2 of both segregating populations, named rtt1 (resistance to temephos 1). Bioinformatics analyses identified a cluster of carboxylesterase genes (CCE) within the rtt1 interval. qRT-PCR demonstrated that different CCEs were up-regulated in F2 resistant individuals from both crosses. However, none exceeded the 2-fold expression. Primary mechanisms for temephos resistance may vary between Ae. aegypti populations, yet also appear to support previous findings suggesting that multiple linked esterase genes may contribute to temephos resistance in the RecR strain as well as other populations. PMID:26576515

  11. High-resolution mapping of the wheat Lr46 pleiotropic rust resistance locus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rust diseases are the most important diseases of wheat globally, and genetic resistance is the most effective method for controlling all three rusts. Numerous resistance genes have been characterized and reported. For typical resistance genes, the mechanism of resistance and the basis of race specif...

  12. The environment exerts a greater influence than the transgene on the transcriptome of field-grown wheat expressing the Pm3b allele.

    PubMed

    Quijano, Carolina Diaz; Brunner, Susanne; Keller, Beat; Gruissem, Wilhelm; Sautter, Christof

    2015-02-01

    Wheat provides 20 % of the calories consumed worldwide. Powdery mildew infections of wheat can result in more than 30 % yield loss but it has been demonstrated that wheat overexpressing Pm3b, an allele of the R gene Pm3, has enhanced resistance against powdery mildew under field conditions. A gene expression profile study using GeneChip Wheat Genome Array and Fluidigm 96.96 Dynamic Arrays was performed to obtain insights into the mode of action of Pm3b and to elucidate the molecular basis of pleiotropic effects observed in three out of four independent transgenic events under field conditions. A cluster analysis of the microarray data and a principal component analysis of the Fluidigm 96.96 Dynamic Arrays data showed that transgenic lines and null segregants grouped together. The microarray analysis of samples from fungicide-treated plants revealed that significantly fewer genes were differentially expressed in Pm3b#1 than in Pm3b#2, which had a pleiotropic phenotype in the field, compared to their null segregants. Together, our data provide evidence that the environment influenced gene expression in the Pm3b lines more than the transgene itself. PMID:25095900

  13. Identification of a locus in arabidopsis controlling both the expression of rhizobacteria-mediated induced systemic resistance (ISR) and basal resistance against Pseudomonas syringae pv. tomato.

    PubMed

    Ton, J; Pieterse, C M; Van Loon, L C

    1999-10-01

    Selected nonpathogenic rhizobacteria with biological disease control activity are able to elicit an induced systemic resistance (ISR) response that is phenotypically similar to pathogen-induced systemic acquired resistance (SAR). Ten ecotypes of Arabidopsis thaliana were screened for their potential to express rhizobacteria-mediated ISR and pathogen-induced SAR against the leaf pathogen Pseudomonas syringae pv. tomato DC3000 (Pst). All ecotypes expressed SAR. However, of the 10 ecotypes tested, ecotypes RLD and Wassilewskija (Ws) did not develop ISR after treatment of the roots with nonpathogenic Pseudomonas fluorescens WCS417r bacteria. This nonresponsive phenotype was associated with relatively high susceptibility to Pst infection. The F1 progeny of crosses between the non-responsive ecotypes RLD and Ws on the one hand, and the responsive ecotypes Columbia (Col) and Landsberg erecta (Ler) on the other hand, were fully capable of expressing ISR and exhibited a relatively high level of basal resistance, similar to that of their WCS417r-responsive parent. This indicates that the potential to express ISR and the relatively high level of basal resistance against Pst are both inherited as dominant traits. Analysis of the F2 and F3 progeny of a Col x RLD cross revealed that inducibility of ISR and relatively high basal resistance against Pst cosegregate in a 3:1 fashion, suggesting that both resistance mechanisms are monogenically determined and genetically linked. Neither the responsiveness to WCS417r nor the relatively high level of basal resistance against Pst were complemented in the F1 progeny of crosses between RLD and Ws, indicating that RLD and Ws are both affected in the same locus, necessary for the expression of ISR and basal resistance against Pst. The corresponding locus, designated ISR1, was mapped between markers B4 and GL1 on chromosome 3. The observed association between ISR and basal resistance against Pst suggests that rhizobacteria-mediated ISR

  14. Development of a novel strategy for fungal transformation based on a mutant locus conferring carboxin-resistance in Magnaporthe oryzae.

    PubMed

    Guo, Min; Zhu, Xiaolei; Li, Hongxia; Tan, Leyong; Pan, Yuemin

    2016-12-01

    The accurate manipulation of genomic integration of mutant alleles or fluorescent fusion-protein constructs is necessary for understanding of pathogenic mechanism of Magnaporthe oryzae. Recently, this can be achieved by integrating of exogenous DNA randomly into genome of this pathogen, but ectopic integration may result in alteration of gene expression or gene disruption due to unpredictable position effects and/or disruption of protein-coding regions. In this study, we establish a novel strategy for locus-specific integration of exogenous DNA via carboxin-resistance reconstitution by a point-mutation (H245L) on succinate dehydrogenase subunit Mosdi1. Independent transformants derived from the same reconstitution construct showed consistent fluorescent signal and undiversified phenotypes, including hyphae growth, conidiation and pathogenicity, in M. oryzae. Meanwhile, 96 % of all transformants integrate correctly into the Mosdi1 locus as a single copy. Furthermore, we provide a vector carrying yeast recombination cassette and thus allow assembly of multiple overlapping DNA fragments by yeast in vivo recombination for gene complementation and protein localization assay. PMID:27558019

  15. Drug-resistant tuberculosis can be predicted by Mycobacterial interspersed repetitive unit locus

    PubMed Central

    Yu-feng, Wen; Chao, Jiang; Xian-feng, Cheng

    2015-01-01

    It is unknown whether MIRU-VNTR (Mycobacterial Interspersed Repetitive Unit-Variable Number of Tandem Repeat) is associated with drug resistance of Mycobacterium tuberculosis. The purpose of this study was to explore the ability of 24 MIRU loci to predict the drug resistance of Isoniazid (INH), Rifampicin (RFP), Streptomycin (SM), Ethambutol (EMB) and Pyrazinamide (PZA). We collected the drug resistance and MIRU loci information of 109 strains of M. tuberculosis from an open database. The results of multivariate logistic regression showed that the VNTR polymorphism of MTUB04 was related to INH resistance [odds ratio (OR) = 2.82, P = 0.00], RFP resistance (OR = 1.91, P = 0.02), SM resistance (OR = 1.98, P = 0.01) and EMB resistance (OR = 1.95, P = 0.03). MIRU40 was associated with INH resistance (OR = 2.22, P = 0.00). MTUB21 was connected with INH resistance (OR = 1.63, P = 0.02) and SM resistance (OR = 1.69, P = 0.01). MIRU26 was correlated with SM resistance (OR = 1.52, P = 0.04). MIRU39 was associated with EMB resistance (OR = 4.07, P = 0.02). The prediction power of MIRU loci were 0.84, 0.70, 0.85, and 0.74 respectively for INH (predicted by MTUB04, MIRU20, and MTUB21), RFP (predicted by MTUB04), SM (predicted by MTUB21 and MIRU26) and EMB (MTUB04 and MIRU39) through ROC analysis. Our results showed that MIRU loci were related to anti-tuberculosis drug and could predict the drug resistance of tuberculosis. PMID:25759689

  16. A Mutation Causing Imidazolinone Resistance Maps to the Csr1 Locus of Arabidopsis thaliana.

    PubMed

    Haughn, G W; Somerville, C R

    1990-04-01

    A mutant of Arabidopsis thaliana, two hundred times more resistant to the imidazolinone herbicide imazapyr than wild-type plants, was isolated by direct selection of seedlings from a mutagenized population. Genetic analysis showed that resistance is due to a single dominant nuclear mutation that could not be separated by recombination from a mutation in the CSR1 gene encoding acetohydroxy acid synthase. Acetohydroxy acid synthase activity in extracts isolated from the mutant was 1000-fold more resistant to inhibition by imazapyr than that of the wild type. The resistant enzyme activity cosegregated with whole plant resistance. These data strongly suggest that the mutation is an allele of CSR1 encoding an imazapyr-resistant AHAS. PMID:16667374

  17. The wheat Sr50 gene reveals rich diversity at a cereal disease resistance locus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We identify the wheat stem rust resistance gene Sr50 by physical mapping, mutation and complementation as homologous to barley Mla encoding a Coiled-Coil-Nucleotide-Binding-Leucine-Rich Repeat (CC-NB-LRR) protein. We show that Sr50 confers a unique resistance specificity, different from Sr31 and oth...

  18. Antisense expression of peach mildew resistance locus O (PpMlo1) gene confers cross-species resistance to powdery mildew in Fragaria x ananassa.

    PubMed

    Jiwan, Derick; Roalson, Eric H; Main, Dorrie; Dhingra, Amit

    2013-12-01

    Powdery mildew (PM) is one of the major plant pathogens. The conventional method of PM control includes frequent use of sulfur-based fungicides adding to production costs and potential harm to the environment. PM remains a major scourge for Rosaceae crops where breeding approaches mainly resort to gene-for-gene resistance. We have tested an alternate source of PM resistance in Rosaceae. Mildew resistance locus O (MLO) has been well studied in barley due to its role in imparting broad spectrum resistance to PM. We identified PpMlo1 (Prunus persica Mlo) in peach and characterized it further to test if a similar mechanism of resistance is conserved in Rosaceae. Due to its recalcitrance in tissue culture, reverse genetic studies involving PpMloI were not feasible in peach. Therefore, Fragaria x ananassa LF9 line, a taxonomic surrogate, was used for functional analysis of PpMlo1. Agrobacterium-mediated transformation yielded transgenic strawberry plants expressing PpMlo1 in sense and antisense orientation. Antisense expression of PpMlo1 in transgenic strawberry plants conferred resistance to Fragaria-specific powdery mildew, Podosphaera macularis. Phylogenetic analysis of 208 putative Mlo gene copies from 35 plant species suggests a large number of duplications of this gene family prior to the divergence of monocots and eudicots, early in eudicot diversification. Our results indicate that the Mlo-based resistance mechanism is functional in Rosaceae, and that Fragaria can be used as a host to test mechanistic function of genes derived from related tree species. To the best of our knowledge, this work is one of the first attempts at testing the potential of using a Mlo-based resistance strategy to combat powdery mildew in Rosaceae. PMID:23728780

  19. Identification of a new locus Ptr(t) required for rice blast resistance gene Pi-ta-mediated resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Resistance to the blast pathogen Magnaporthe oryzae is proposed to be initiated by physical binding of a putative cytoplasmic receptor encoded by a NBS-type resistance gene, Pi-ta, to the processed elicitor encoded by the corresponding avirulence gene AVR-Pita. Here we report the identification of a...

  20. Genetics of resistance to African trypanosomes: role of the H-2 locus in determining resistance to infection with Trypanosoma rhodesiense.

    PubMed Central

    Levine, R F; Mansfield, J M

    1981-01-01

    Susceptibility and resistance to Trypanosoma rhodesiense infections in inbred and H-2 congenic strains of mice were studied. Mean survival times and patterns of parasitemia were examined. C3HeB/FeJ mice were highly susceptible; CBA/J, A/J, and BALB/cByJ mice displayed an intermediate level of susceptibility; whereas C57BL/10 mice were highly resistant. H-2 congenic strains with the BL/10 background resembled the BL/10 parental type, thereby suggesting that the major histocompatibility complex does not play a major role in regulating resistance and susceptibility to infection with T. rhodesiense. PMID:7309237

  1. Exome and transcriptome sequencing of Aedes aegypti identifies a locus that confers resistance to Brugia malayi and alters the immune response.

    PubMed

    Juneja, Punita; Ariani, Cristina V; Ho, Yung Shwen; Akorli, Jewelna; Palmer, William J; Pain, Arnab; Jiggins, Francis M

    2015-03-01

    Many mosquito species are naturally polymorphic for their abilities to transmit parasites, a feature which is of great interest for controlling vector-borne disease. Aedes aegypti, the primary vector of dengue and yellow fever and a laboratory model for studying lymphatic filariasis, is genetically variable for its capacity to harbor the filarial nematode Brugia malayi. The genome of Ae. aegypti is large and repetitive, making genome resequencing difficult and expensive. We designed exome captures to target protein-coding regions of the genome, and used association mapping in a wild Kenyan population to identify a single, dominant, sex-linked locus underlying resistance. This falls in a region of the genome where a resistance locus was previously mapped in a line established in 1936, suggesting that this polymorphism has been maintained in the wild for the at least 80 years. We then crossed resistant and susceptible mosquitoes to place both alleles of the gene into a common genetic background, and used RNA-seq to measure the effect of this locus on gene expression. We found evidence for Toll, IMD, and JAK-STAT pathway activity in response to early stages of B. malayi infection when the parasites are beginning to die in the resistant genotype. We also found that resistant mosquitoes express anti-microbial peptides at the time of parasite-killing, and that this expression is suppressed in susceptible mosquitoes. Together, we have found that a single resistance locus leads to a higher immune response in resistant mosquitoes, and we identify genes in this region that may be responsible for this trait. PMID:25815506

  2. Exome and Transcriptome Sequencing of Aedes aegypti Identifies a Locus That Confers Resistance to Brugia malayi and Alters the Immune Response

    PubMed Central

    Juneja, Punita; Ariani, Cristina V.; Ho, Yung Shwen; Akorli, Jewelna; Palmer, William J.; Pain, Arnab; Jiggins, Francis M.

    2015-01-01

    Many mosquito species are naturally polymorphic for their abilities to transmit parasites, a feature which is of great interest for controlling vector-borne disease. Aedes aegypti, the primary vector of dengue and yellow fever and a laboratory model for studying lymphatic filariasis, is genetically variable for its capacity to harbor the filarial nematode Brugia malayi. The genome of Ae. aegypti is large and repetitive, making genome resequencing difficult and expensive. We designed exome captures to target protein-coding regions of the genome, and used association mapping in a wild Kenyan population to identify a single, dominant, sex-linked locus underlying resistance. This falls in a region of the genome where a resistance locus was previously mapped in a line established in 1936, suggesting that this polymorphism has been maintained in the wild for the at least 80 years. We then crossed resistant and susceptible mosquitoes to place both alleles of the gene into a common genetic background, and used RNA-seq to measure the effect of this locus on gene expression. We found evidence for Toll, IMD, and JAK-STAT pathway activity in response to early stages of B. malayi infection when the parasites are beginning to die in the resistant genotype. We also found that resistant mosquitoes express anti-microbial peptides at the time of parasite-killing, and that this expression is suppressed in susceptible mosquitoes. Together, we have found that a single resistance locus leads to a higher immune response in resistant mosquitoes, and we identify genes in this region that may be responsible for this trait. PMID:25815506

  3. Identification of a genetic locus responsible for antimicrobial peptide resistance in Clostridium difficile.

    PubMed

    McBride, Shonna M; Sonenshein, Abraham L

    2011-01-01

    Clostridium difficile causes chronic intestinal disease, yet little is understood about how the bacterium interacts with and survives in the host. To colonize the intestine and cause persistent disease, the bacterium must circumvent killing by host innate immune factors, such as cationic antimicrobial peptides (CAMPs). In this study, we investigated the effect of model CAMPs on growth and found that C. difficile is not only sensitive to these compounds but also responds to low levels of CAMPs by expressing genes that lead to CAMP resistance. By plating the bacterium on medium containing the CAMP nisin, we isolated a mutant capable of growing in three times the inhibitory concentration of CAMPs. This mutant also showed increased resistance to the CAMPs gallidermin and polymyxin B, demonstrating tolerance to different types of antimicrobial peptides. We identified the mutated gene responsible for the resistance phenotype as CD1352. This gene encodes a putative orphan histidine kinase that lies adjacent to a predicted ABC transporter operon (CD1349 to CD1351). Transcriptional analysis of the ABC transporter genes revealed that this operon was upregulated in the presence of nisin in wild-type cells and was more highly expressed in the CD1352 mutant. The insertional disruption of the CD1349 gene resulted in significant decreases in resistance to the CAMPs nisin and gallidermin but not polymyxin B. Because of their role in cationic antimicrobial peptide resistance, we propose the designation cprABC for genes CD1349 to CD1351 and cprK for the CD1352 gene. These results provide the first evidence of a C. difficile gene associated with antimicrobial peptide resistance. PMID:20974818

  4. Leaf rust resistance in wheat line RL6062 is an allele at the Lr3 locus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    RL6062, a 'Thatcher' backcross line of wheat (Triticum aestivum L.) has resistance to leaf rust (caused by Puccinia triticina) derived from a line of common wheat from Iran. RL6062 has an intermediate infection type (IT) of small to moderate uredinia surrounded by distinct chlorosis. RL6062 was cros...

  5. Tumor progression locus 2 (TPL2) regulates obesity-associated inflammation and insulin resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Obesity-associated low-grade systemic inflammation resulting from increased adipose mass is strongly related to the development of insulin resistance and type 2 diabetes as well as other metabolic complications. Recent studies have demonstrated the obese metabolic state can be improved by ablating ...

  6. Fine mapping of barley locus Rps6 conferring resistance to wheat stripe rust

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a major disease of wheat that is causing large economic losses in many wheat-growing regions of the world. Deployment of Pst resistance genes has been an effective strategy for controlling this pathogen, but many of these gen...

  7. Mutagenesis at the ouabain-resistance locus in human diploid fibroblasts.

    PubMed

    Buchwald, M

    1977-09-01

    The variables affecting the frequency of ouabain-resistant mutant clones have been studied in a strain of foetal lung fibroblasts. Optimum mutant recovery was obtained when cells were selected in 10(-6) M ouabain at a cell density of 2 X 10(4) cells/cm 2 (10(6) cell per 100-mm dish). The spontaneous mutation rate was estimated to be 4 X 10(-8) per cell generation. Treatment with the mutagens ethyl methanesulfonate (EMS), N-methyl-N' -nitro-N-nitrosoguanidine, and UV light increased the frequency of mutant colonies by an order of magnitude. The maximum number of mutants after mutagenesis with EMS occurred after two population doublings of growth in non-selective medium prior to selection and depended on the dose of EMS. Ouabain-resistance is a useful marker for studies of quantitative mutagenesis in human cells. PMID:904650

  8. Cloning and analysis of a locus (mcr) involved in mitomycin C resistance in Streptomyces lavendulae.

    PubMed Central

    August, P. R.; Flickinger, M. C.; Sherman, D. H.

    1994-01-01

    Two genes (mcrA and mcrB) from Streptomyces lavendulae that together confer resistance to mitomycin C were identified. This DNA appears to comprise a polycistronic operon with a drug-inducible leaderless mRNA. The deduced amino acid sequence of mcrA shows similarity to sequences of a special class of bacterial, plant, and animal oxygen oxidoreductases. Images PMID:7517396

  9. Receptor-like genes in the major resistance locus of lettuce are subject to divergent selection.

    PubMed Central

    Meyers, B C; Shen, K A; Rohani, P; Gaut, B S; Michelmore, R W

    1998-01-01

    Disease resistance genes in plants are often found in complex multigene families. The largest known cluster of disease resistance specificities in lettuce contains the RGC2 family of genes. We compared the sequences of nine full-length genomic copies of RGC2 representing the diversity in the cluster to determine the structure of genes within this family and to examine the evolution of its members. The transcribed regions range from at least 7.0 to 13.1 kb, and the cDNAs contain deduced open reading frames of approximately 5. 5 kb. The predicted RGC2 proteins contain a nucleotide binding site and irregular leucine-rich repeats (LRRs) that are characteristic of resistance genes cloned from other species. Unique features of the RGC2 gene products include a bipartite LRR region with >40 repeats. At least eight members of this family are transcribed. The level of sequence diversity between family members varied in different regions of the gene. The ratio of nonsynonymous (Ka) to synonymous (Ks) nucleotide substitutions was lowest in the region encoding the nucleotide binding site, which is the presumed effector domain of the protein. The LRR-encoding region showed an alternating pattern of conservation and hypervariability. This alternating pattern of variation was also found in all comparisons within families of resistance genes cloned from other species. The Ka /Ks ratios indicate that diversifying selection has resulted in increased variation at these codons. The patterns of variation support the predicted structure of LRR regions with solvent-exposed hypervariable residues that are potentially involved in binding pathogen-derived ligands. PMID:9811792

  10. Molecular genetic analysis of a locus required for resistance to antimicrobial peptides in Salmonella typhimurium.

    PubMed Central

    Parra-Lopez, C; Baer, M T; Groisman, E A

    1993-01-01

    The innate immunity of vertebrates and invertebrates to microbial infection is mediated in part by small cationic peptides with antimicrobial activity. Successful pathogens have evolved mechanisms to withstand the antibiotic activity of these molecules. We have isolated a set of genes from Salmonella typhimurium which are required for virulence and resistance to the antimicrobial peptides melittin and protamine. Sequence analysis of a 5.7 kb segment from the wild-type plasmid conferring resistance to protamine contained five open reading frames: sapA, sapB, sapC, sapD and sapF, organized in an operon structure and transcribed as a 5.3 kb mRNA. SapD and SapF exhibited similarity with the 'ATP binding cassette' family of transporters including the bacterial Opp and SpoOK, involved in the uptake of oligopeptides; the yeast STE6, necessary for the export of a peptide pheromone; and the mammalian mdr, which mediates resistance to chemotherapeutic agents in cancer cells. SapA showed identity with other periplasmic solute binding proteins involved in peptide transport. The SapABCDF system constitutes a novel transporter for enteric bacteria and the first one harboring a periplasmic component with a role in virulence. Images PMID:8223423

  11. Rapid, Transient Changes at the env Locus of Plasma Human Immunodeficiency Virus Type 1 Populations during the Emergence of Protease Inhibitor Resistance

    PubMed Central

    Delwart, Eric L.; Pan, Heng; Neumann, Avidan; Markowitz, Martin

    1998-01-01

    Plasma human immunodeficiency virus type 1 (HIV-1) populations were genetically analyzed at their most variable locus, the envelope gene, during the rapid emergence of resistance to protease inhibitor monotherapy. Plasma virus populations remained genetically constant prior to drug treatment and during the 1 to 2 weeks following initiation of therapy, while viremia fell 10- to 100-fold. Concomitant with rapid plasma viremia rebounds associated with the emergence of drug-resistant virus, marked alterations were then detected at the env locus. Plasma population changes lasted only a few weeks before the reappearance of the pretreatment envelope variants. The emergence of resistance to single protease inhibitors was therefore associated with major but transient changes at a nonselected locus. Selection for resistance to single protease inhibitors thus appears to be more complex than the continued replication of a large, random, and therefore genetically representative sampling of the pretreatment plasma population. The possibility that drug-privileged anatomical sites containing distinct envelope variants and/or a small effective HIV-1 population size account for these results is discussed. PMID:9499102

  12. Usefulness of double locus sequence typing (DLST) for regional and international epidemiological surveillance of methicilin-resistant Staphylococcus aureus.

    PubMed

    Basset, P; Senn, L; Prod'hom, G; Bille, J; Francioli, P; Zanetti, G; Blanc, D S

    2010-08-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of nosocomial infections worldwide. To differentiate reliably among S. aureus isolates, we recently developed double locus sequence typing (DLST) based on the analysis of partial sequences of clfB and spa genes. In the present study, we evaluated the usefulness of DLST for epidemiological investigations of MRSA by routinely typing 1242 strains isolated in Western Switzerland. Additionally, particular local and international collections were typed by pulsed field gel electrophoresis (PFGE) and DLST to check the compatibility of DLST with the results obtained by PFGE, and for international comparisons. Using DLST, we identified the major MRSA clones of Western Switzerland, and demonstrated the close relationship between local and international clones. The congruence of 88% between the major PFGE and DLST clones indicated that our results obtained by DLST were compatible with earlier results obtained by PFGE. DLST could thus easily be incorporated in a routine surveillance procedure. In addition, the unambiguous definition of DLST types makes this method more suitable than PFGE for long-term epidemiological surveillance. Finally, the comparison of the results obtained by DLST, multilocus sequence typing, PFGE, Staphylococcal cassette chromosome mec typing and the detection of Panton-Valentine leukocidin genes indicated that no typing scheme should be used on its own. It is only the combination of data from different methods that gives the best chance of describing precisely the epidemiology and phylogeny of MRSA. PMID:19832717

  13. Evaluation of PM-3 Chemistry Data and Possible Interpretations of 3H Observations, Revision 0

    SciTech Connect

    Andrews, Robert; Marutzky, Sam J.

    2015-02-01

    This report summarizes the analyses of the groundwater results from sampling of PM-3-1 (deep) and PM-3-2 (shallow), with a particular focus of evaluating the groundwater geochemistry data in comparison to the geochemistry observed in other wells in the Thirsty Canyon area as well as to evaluate the potential source of 3H observed in these piezometers from previous sampling activities, which employed depth-discrete bailers or a Bennett submersible piston pump.

  14. Comparative sequence analysis of the potato cyst nematode resistance locus H1 reveals a major lack of co-linearity between three haplotypes in potato (Solanum tuberosum ssp.).

    PubMed

    Finkers-Tomczak, Anna; Bakker, Erin; de Boer, Jan; van der Vossen, Edwin; Achenbach, Ute; Golas, Tomasz; Suryaningrat, Suwardi; Smant, Geert; Bakker, Jaap; Goverse, Aska

    2011-02-01

    The H1 locus confers resistance to the potato cyst nematode Globodera rostochiensis pathotypes 1 and 4. It is positioned at the distal end of chromosome V of the diploid Solanum tuberosum genotype SH83-92-488 (SH) on an introgression segment derived from S. tuberosum ssp. andigena. Markers from a high-resolution genetic map of the H1 locus (Bakker et al. in Theor Appl Genet 109:146-152, 2004) were used to screen a BAC library to construct a physical map covering a 341-kb region of the resistant haplotype coming from SH. For comparison, physical maps were also generated of the two haplotypes from the diploid susceptible genotype RH89-039-16 (S. tuberosum ssp. tuberosum/S. phureja), spanning syntenic regions of 700 and 319 kb. Gene predictions on the genomic segments resulted in the identification of a large cluster consisting of variable numbers of the CC-NB-LRR type of R genes for each haplotype. Furthermore, the regions were interspersed with numerous transposable elements and genes coding for an extensin-like protein and an amino acid transporter. Comparative analysis revealed a major lack of gene order conservation in the sequences of the three closely related haplotypes. Our data provide insight in the evolutionary mechanisms shaping the H1 locus and will facilitate the map-based cloning of the H1 resistance gene. PMID:21049265

  15. Multigeneic QTL: the laccase encoded within the soybean Rfs2/rhg1 locus inferred to underlie part of the dual resistance to cyst nematode and sudden death syndrome.

    PubMed

    Iqbal, M J; Ahsan, R; Afzal, A J; Jamai, A; Meksem, K; El-Shemy, H A; Lightfoot, D A

    2009-01-01

    Multigeneic QTL present significant problems to analysis. Resistance to soybean (Glycine max (L) Merr.) sudden death syndrome (SDS) caused by Fusarium virguliforme was partly underlain by QRfs2 that was clustered with, or pleiotropic to, the multigeneic rhg1 locus providing resistance to soybean cyst nematode (SCN; Heterodera glycines). A group of five genes were found between the two markers that delimited the Rfs2/rhg1 locus. One of the five genes was predicted to encode an unusual diphenol oxidase (laccase; EC 1.10.3.2). The aim of this study was to characterize this member of the soybean laccase gene-family and explore its involvement in SDS resistance. A genomic clone and a full length cDNA was isolated from resistant cultivar 'Forrest' that were different among susceptible cultivars 'Asgrow 3244' and 'Williams 82' at four residues R/H168, I/M271, R/H330, E/K470. Additional differences were found in six of the seven introns and the promoter region. Transcript abundance (TA) among genotypes that varied for resistance to SDS or SCN did not differ significantly. Therefore the protein activity was inferred to underlie resistance. Protein expressed in yeast pYES2/NTB had weak enzyme activity with common substrates but good activity with root phenolics. The Forrest isoform may underlie both QRfs2 and rhg1. PMID:19193960

  16. Genetic Characterization of Resistance to Wheat Stem Rust Race TTKSK in Landrace and Wild Barley Accessions Identifies the rpg4/Rpg5 Locus.

    PubMed

    Mamo, Bullo Erena; Smith, Kevin P; Brueggeman, Robert S; Steffenson, Brian J

    2015-01-01

    Race TTKSK of the wheat stem rust pathogen (Puccinia graminis f. sp. tritici) threatens the production of wheat and barley worldwide because of its broad-spectrum virulence on many widely grown cultivars. Sources of resistance against race TTKSK were recently identified in several barley landraces (Hordeum vulgare subsp. vulgare) and wild barley accessions (H. vulgare subsp. spontaneum). The objectives of this study were to characterize the inheritance of resistance to wheat stem rust race TTKSK in four barley landraces (Hv501, Hv545, Hv602, and Hv612) and two wild barley (WBDC213 and WBDC345) accessions, map the resistance genes, and determine the allelic relationships among the genes in these accessions and the previously described rpg4/Rpg5 locus. Resistant accessions were crossed with the susceptible cv. Steptoe and resulting F3 populations were evaluated for resistance to race TTKSK at the seedling stage. Segregation of F3 families in populations involving the resistance sources of Hv501, Hv545, Hv612, WBDC213, and WBDC345 fit a 1:2:1 ratio for homozygous resistant (HR)/segregating (SEG)/homozygous susceptible (HS) progenies (with χ2=2.27 to 5.87 and P=0.053 to 0.321), indicating that a single gene confers resistance to race TTKSK. Segregation of F3 families in cross Steptoe/Hv602 did not fit a 1:2:1 ratio (HR/SEG/HS of 20:47:43 with χ2=11.95 and P=0.003), indicating that more than one gene is involved in imparting resistance to race TTKSK. Bulked segregant analysis using >1,500 single-nucleotide polymorphism markers positioned a resistance locus in all six populations on chromosome 5HL in very close proximity to the known location of the rpg4/Rpg5 complex locus. Allelism tests were conducted by making crosses among resistant accessions Hv501, Hv545, and Hv612 and also Q21861 with the rpg4/Rpg5 complex. No segregation was observed in F2 families inoculated with race TTKSK, demonstrating that all Hv lines carry the same allele for resistance and that it

  17. Role of the locus coeruleus in enhanced orexin A-induced spontaneous physical activity in obesity-resistant rats

    PubMed Central

    Perez-Leighton, Claudio E.; Billington, Charles J.; Kotz, Catherine M.

    2013-01-01

    Orexin/hypocretin terminals innervate noradrenergic locus coeruleus (LC) neurons that project to the prefrontral cortex, which may influence spontaneous physical activity (SPA) and energy balance. Obesity-resistant (OR) rats have higher orexin receptors (OXR) mRNA in the LC and other brain regions, as well as lower adiposity compared with obese rats. These findings led us to hypothesize that orexin activity in the LC is relevant for the OR phenotype. We compared OR rats to Sprague-Dawley rats. We predicted that: 1) brain OXR expression pattern is sufficient to differentiate OR from non-bred Sprague-Dawley rats; 2) nonresting energy expenditure (NREE) and orexin A (OXA)-stimulated SPA after injection in LC would be greater in OR rats; and 3) the effect of OXA on SPA would be greater than its effect on feeding. OXR mRNA from 11 brain sites and the SPA and feeding responses to OXA in the LC were determined. Body composition, basal SPA, and EE were determined. Principal component analysis of the OXR expression pattern differentiates OR and Sprague-Dawley rats and suggests the OXR mRNA in the LC is important in defining the OR phenotype. Compared with Sprague-Dawley rats, OR rats had greater SPA and NREE and lower resting EE and adiposity. SPA responsivity to OXA in the LC was greater in OR rats compared with Sprague-Dawley rats. OXA in the LC did not stimulate feeding in OR or Sprague-Dawley rats. These data suggest that the LC is a prominent site modulating OXA-stimulated SPA, which promotes lower adiposity and higher nonresting EE. PMID:24089383

  18. Molecular Cloning and Functional Analysis of UV RESISTANCE LOCUS 8 (PeUVR8) from Populus euphratica.

    PubMed

    Mao, Ke; Wang, Lina; Li, Yuan-Yuan; Wu, Rongling

    2015-01-01

    Ultraviolet-B (UV-B; 280-315 nm) light, which is an integral part of the solar radiation reaching the surface of the Earth, induces a broad range of physiological responses in plants. The UV RESISTANCE LOCUS 8 (UVR8) protein is the first and only light photoreceptor characterized to date that is specific for UV-B light and it regulates various aspects of plant growth and development in response to UV-B light. Despite its involvement in the control of important plant traits, most studies on UV-B photoreceptors have focused on Arabidopsis and no data on UVR8 function are available for forest trees. In this study, we isolated a homologue of the UV receptor UVR8 of Arabidopsis, PeUVR8, from Populus euphratica (Euphrates poplar) and analyzed its structure and function in detail. The deduced PeUVR8 amino acid sequence contained nine well-conserved regulator of chromosome condensation 1 (RCC1) repeats and the region 27 amino acids from the C terminus (C27) that interact with COP1 (CONSTITUTIVELY PHOTOMORPHOGENIC1). Secondary and tertiary structure analysis showed that PeUVR8 shares high similarity with the AtUVR8 protein from Arabidopsis thaliana. Using heterologous expression in Arabidopsis, we showed that PeUVR8 overexpression rescued the uvr8 mutant phenotype. In addition, PeUVR8 overexpression in wild-type background seedlings grown under UV-B light inhibited hypocotyl elongation and enhanced anthocyanin accumulation. Furthermore, we examined the interaction between PeUVR8 and AtCOP1 using a bimolecular fluorescence complementation (BiFC) assay. Our data provide evidence that PeUVR8 plays important roles in the control of photomorphogenesis in planta. PMID:26171608

  19. Analysis of a plant complex resistance gene locus underlying immune-related hybrid incompatibility and its occurrence in nature.

    PubMed

    Alcázar, Rubén; von Reth, Marcel; Bautor, Jaqueline; Chae, Eunyoung; Weigel, Detlef; Koornneef, Maarten; Parker, Jane E

    2014-12-01

    Mechanisms underlying speciation in plants include detrimental (incompatible) genetic interactions between parental alleles that incur a fitness cost in hybrids. We reported on recessive hybrid incompatibility between an Arabidopsis thaliana strain from Poland, Landsberg erecta (Ler), and many Central Asian A. thaliana strains. The incompatible interaction is determined by a polymorphic cluster of Toll/interleukin-1 receptor-nucleotide binding-leucine rich repeat (TNL) RPP1 (Recognition of Peronospora parasitica1)-like genes in Ler and alleles of the receptor-like kinase Strubbelig Receptor Family 3 (SRF3) in Central Asian strains Kas-2 or Kond, causing temperature-dependent autoimmunity and loss of growth and reproductive fitness. Here, we genetically dissected the RPP1-like Ler locus to determine contributions of individual RPP1-like Ler (R1-R8) genes to the incompatibility. In a neutral background, expression of most RPP1-like Ler genes, except R3, has no effect on growth or pathogen resistance. Incompatibility involves increased R3 expression and engineered R3 overexpression in a neutral background induces dwarfism and sterility. However, no individual RPP1-like Ler gene is sufficient for incompatibility between Ler and Kas-2 or Kond, suggesting that co-action of at least two RPP1-like members underlies this epistatic interaction. We find that the RPP1-like Ler haplotype is frequent and occurs with other Ler RPP1-like alleles in a local population in Gorzów Wielkopolski (Poland). Only Gorzów individuals carrying the RPP1-like Ler haplotype are incompatible with Kas-2 and Kond, whereas other RPP1-like alleles in the population are compatible. Therefore, the RPP1-like Ler haplotype has been maintained in genetically different individuals at a single site, allowing exploration of forces shaping the evolution of RPP1-like genes at local and regional population scales. PMID:25503786

  20. Molecular Cloning and Functional Analysis of UV RESISTANCE LOCUS 8 (PeUVR8) from Populus euphratica

    PubMed Central

    Mao, Ke; Wang, Lina; Li, Yuan-Yuan; Wu, Rongling

    2015-01-01

    Ultraviolet-B (UV-B; 280–315 nm) light, which is an integral part of the solar radiation reaching the surface of the Earth, induces a broad range of physiological responses in plants. The UV RESISTANCE LOCUS 8 (UVR8) protein is the first and only light photoreceptor characterized to date that is specific for UV-B light and it regulates various aspects of plant growth and development in response to UV-B light. Despite its involvement in the control of important plant traits, most studies on UV-B photoreceptors have focused on Arabidopsis and no data on UVR8 function are available for forest trees. In this study, we isolated a homologue of the UV receptor UVR8 of Arabidopsis, PeUVR8, from Populus euphratica (Euphrates poplar) and analyzed its structure and function in detail. The deduced PeUVR8 amino acid sequence contained nine well-conserved regulator of chromosome condensation 1 (RCC1) repeats and the region 27 amino acids from the C terminus (C27) that interact with COP1 (CONSTITUTIVELY PHOTOMORPHOGENIC1). Secondary and tertiary structure analysis showed that PeUVR8 shares high similarity with the AtUVR8 protein from Arabidopsis thaliana. Using heterologous expression in Arabidopsis, we showed that PeUVR8 overexpression rescued the uvr8 mutant phenotype. In addition, PeUVR8 overexpression in wild-type background seedlings grown under UV-B light inhibited hypocotyl elongation and enhanced anthocyanin accumulation. Furthermore, we examined the interaction between PeUVR8 and AtCOP1 using a bimolecular fluorescence complementation (BiFC) assay. Our data provide evidence that PeUVR8 plays important roles in the control of photomorphogenesis in planta. PMID:26171608

  1. Transfer of the Rsv3 locus from ‘Harosoy’ for resistance to soybean mosaic virus strains C and D in Japan

    PubMed Central

    Kato, Shin; Takada, Yoshitake; Shimamura, Satoshi; Hirata, Kaori; Sayama, Takashi; Taguchi-Shiobara, Fumio; Ishimoto, Masao; Kikuchi, Akio; Nishio, Takeshi

    2016-01-01

    Resistance to soybean mosaic virus (SMV) is imperative for soybean (Glycine max (L.) Merr.) production in the Tohoku region. Molecular markers for SMV resistance were previously reported for U.S. SMV strains, but they cannot be applied because of the differences in strain classification between Japan and the U.S. A U.S. variety ‘Harosoy’ has been used mainly as a donor of resistance to SMV strains C and D in a Japanese breeding program, resulting in resistant varieties such as ‘Fukuibuki.’ Because ‘Harosoy’ harbors the Rsv3 gene conferring resistance to the virulent SMV strain groups, G5 through G7, it appears that the Rsv3 gene confers resistance to strains C and D. In this study, we introduced resistance to the two strains from ‘Fukuibuki’ into a leading variety ‘Ohsuzu’ by recurrent backcrossing with marker-assisted selection. All lines selected with markers near Rsv3 showed resistance to the strains, suggesting that the Rsv3 locus is responsible for the resistance. Three years of trials showed that one of the breeding lines, ‘Tohoku 169,’ was equivalent to ‘Ohsuzu’ with respect to agricultural characteristics such as seed size, maturity date, and seed yield, except for the SMV resistance. PMID:27162503

  2. Genomic and Transcriptomic Associations Identify a New Insecticide Resistance Phenotype for the Selective Sweep at the Cyp6g1 Locus of Drosophila melanogaster.

    PubMed

    Battlay, Paul; Schmidt, Joshua M; Fournier-Level, Alexandre; Robin, Charles

    2016-01-01

    Scans of the Drosophila melanogaster genome have identified organophosphate resistance loci among those with the most pronounced signature of positive selection. In this study, the molecular basis of resistance to the organophosphate insecticide azinphos-methyl was investigated using the Drosophila Genetic Reference Panel, and genome-wide association. Recently released full transcriptome data were used to extend the utility of the Drosophila Genetic Reference Panel resource beyond traditional genome-wide association studies to allow systems genetics analyses of phenotypes. We found that both genomic and transcriptomic associations independently identified Cyp6g1, a gene involved in resistance to DDT and neonicotinoid insecticides, as the top candidate for azinphos-methyl resistance. This was verified by transgenically overexpressing Cyp6g1 using natural regulatory elements from a resistant allele, resulting in a 6.5-fold increase in resistance. We also identified four novel candidate genes associated with azinphos-methyl resistance, all of which are involved in either regulation of fat storage, or nervous system development. In Cyp6g1, we find a demonstrable resistance locus, a verification that transcriptome data can be used to identify variants associated with insecticide resistance, and an overlap between peaks of a genome-wide association study, and a genome-wide selective sweep analysis. PMID:27317781

  3. Genomic and Transcriptomic Associations Identify a New Insecticide Resistance Phenotype for the Selective Sweep at the Cyp6g1 Locus of Drosophila melanogaster

    PubMed Central

    Battlay, Paul; Schmidt, Joshua M.; Fournier-Level, Alexandre; Robin, Charles

    2016-01-01

    Scans of the Drosophila melanogaster genome have identified organophosphate resistance loci among those with the most pronounced signature of positive selection. In this study, the molecular basis of resistance to the organophosphate insecticide azinphos-methyl was investigated using the Drosophila Genetic Reference Panel, and genome-wide association. Recently released full transcriptome data were used to extend the utility of the Drosophila Genetic Reference Panel resource beyond traditional genome-wide association studies to allow systems genetics analyses of phenotypes. We found that both genomic and transcriptomic associations independently identified Cyp6g1, a gene involved in resistance to DDT and neonicotinoid insecticides, as the top candidate for azinphos-methyl resistance. This was verified by transgenically overexpressing Cyp6g1 using natural regulatory elements from a resistant allele, resulting in a 6.5-fold increase in resistance. We also identified four novel candidate genes associated with azinphos-methyl resistance, all of which are involved in either regulation of fat storage, or nervous system development. In Cyp6g1, we find a demonstrable resistance locus, a verification that transcriptome data can be used to identify variants associated with insecticide resistance, and an overlap between peaks of a genome-wide association study, and a genome-wide selective sweep analysis. PMID:27317781

  4. Quinolone resistance locus nfxD of Escherichia coli is a mutant allele of the parE gene encoding a subunit of topoisomerase IV.

    PubMed Central

    Breines, D M; Ouabdesselam, S; Ng, E Y; Tankovic, J; Shah, S; Soussy, C J; Hooper, D C

    1997-01-01

    The locus nfxD, which contributes to high-level quinolone resistance in Escherichia coli KF111b (gyrAr nfxB nfxD), is only expressed in the presence of a gyrA mutation, and maps to the region of the parC and parE genes, was outcrossed into strain KF130, creating strain DH161 (gyrAr nfxD). DNA sequence analysis of DH161 revealed no changes in the topoisomerase IV parC quinolone resistance-determining region but did identify a single T-to-A mutation in parE at codon 445, leading to a change from Leu to His. Full-length cloned parE+ partially complemented the resistance phenotype in KF111b and DH161, but did not complement the resistance phenotype in strain KF130 (gyrAr). No complementation was seen with cloned, truncated parE+. To confirm these findings, gyrAr was first outcrossed from KF130 into E. coli W3110parE10 [parE temperature sensitive(Ts)] and KL16. The transduced strains KL16 and W3110parE10 were subsequently transformed with plasmids containing cloned parE from DH161 or KL16. Cloned parE from DH161 increased norfloxacin resistance in the parE(Ts) background twofold at 30 degrees C and fourfold at 42 degrees C compared to those for cloned parE from KL16. The same experiment with a non-Ts background revealed a twofold increase in the norfloxacin MIC at both 30 and 42 degrees C. These data identify the nfxD conditional resistance locus as a mutant allele of parE. This report is the first of a quinolone-resistant parE mutant and confirms the role of topoisomerase IV as a secondary target of norfloxacin in E. coli. PMID:8980775

  5. Genetics and Molecular Mapping of Black Rot Resistance Locus Xca1bc on Chromosome B-7 in Ethiopian Mustard (Brassica carinata A. Braun).

    PubMed

    Sharma, Brij Bihari; Kalia, Pritam; Yadava, Devendra Kumar; Singh, Dinesh; Sharma, Tilak Raj

    2016-01-01

    Black rot caused by Xanthomonas campestris pv. campestris (Pam.) Dowson is the most destructive disease of cauliflower causing huge loss to the farmers throughout the world. Since there are limited sources of resistance to black rot in B. oleracea (C genome Brassica), exploration of A and B genomes of Brassica was planned as these were thought to be potential reservoirs of black rot resistance gene(s). In our search for new gene(s) for black rot resistance, F2 mapping population was developed in Brassica carinata (BBCC) by crossing NPC-17, a susceptible genotype with NPC-9, a resistant genotype. Out of 364 Intron length polymorphic markers and microsatellite primers used in this study, 41 distinguished the parental lines. However, resistant and susceptible bulks could be distinguished by three markers At1g70610, SSR Na14-G02 and At1g71865 which were used for genotyping of F2 mapping population. These markers were placed along the resistance gene, according to order, covering a distance of 36.30 cM. Intron length polymorphic markers At1g70610 and At1g71865 were found to be linked to black rot resistance locus (Xca1bc) at 6.2 and 12.8 cM distance, respectively. This is the first report of identification of markers linked to Xca1bc locus in Brassica carinata on B-7 linkage group. Intron length polymorphic markers provided a novel and attractive option for marker assisted selection due to high cross transferability and cost effectiveness for marker assisted alien gene introgression into cauliflower. PMID:27023128

  6. Genetics and Molecular Mapping of Black Rot Resistance Locus Xca1bc on Chromosome B-7 in Ethiopian Mustard (Brassica carinata A. Braun)

    PubMed Central

    Sharma, Brij Bihari; Kalia, Pritam; Yadava, Devendra Kumar; Singh, Dinesh; Sharma, Tilak Raj

    2016-01-01

    Black rot caused by Xanthomonas campestris pv. campestris (Pam.) Dowson is the most destructive disease of cauliflower causing huge loss to the farmers throughout the world. Since there are limited sources of resistance to black rot in B. oleracea (C genome Brassica), exploration of A and B genomes of Brassica was planned as these were thought to be potential reservoirs of black rot resistance gene(s). In our search for new gene(s) for black rot resistance, F2 mapping population was developed in Brassica carinata (BBCC) by crossing NPC-17, a susceptible genotype with NPC-9, a resistant genotype. Out of 364 Intron length polymorphic markers and microsatellite primers used in this study, 41 distinguished the parental lines. However, resistant and susceptible bulks could be distinguished by three markers At1g70610, SSR Na14-G02 and At1g71865 which were used for genotyping of F2 mapping population. These markers were placed along the resistance gene, according to order, covering a distance of 36.30 cM. Intron length polymorphic markers At1g70610 and At1g71865 were found to be linked to black rot resistance locus (Xca1bc) at 6.2 and 12.8 cM distance, respectively. This is the first report of identification of markers linked to Xca1bc locus in Brassica carinata on B-7 linkage group. Intron length polymorphic markers provided a novel and attractive option for marker assisted selection due to high cross transferability and cost effectiveness for marker assisted alien gene introgression into cauliflower. PMID:27023128

  7. Chimerization at the AQP2-AQP3 locus is the genetic basis of melarsoprol-pentamidine cross-resistance in clinical Trypanosoma brucei gambiense isolates.

    PubMed

    Graf, Fabrice E; Baker, Nicola; Munday, Jane C; de Koning, Harry P; Horn, David; Mäser, Pascal

    2015-08-01

    Aquaglyceroporin-2 is a known determinant of melarsoprol-pentamidine cross-resistance in Trypanosoma brucei brucei laboratory strains. Recently, chimerization at the AQP2-AQP3 tandem locus was described from melarsoprol-pentamidine cross-resistant Trypanosoma brucei gambiense isolates from sleeping sickness patients in the Democratic Republic of the Congo. Here, we demonstrate that reintroduction of wild-type AQP2 into one of these isolates fully restores drug susceptibility while expression of the chimeric AQP2/3 gene in aqp2-aqp3 null T. b. brucei does not. This proves that AQP2-AQP3 chimerization is the cause of melarsoprol-pentamidine cross-resistance in the T. b. gambiense isolates. PMID:26042196

  8. Adaptation of Trypanosoma rhodesiense to hypohaptoglobinaemic serum requires transcription of the APOL1 resistance gene in a RNA polymerase I locus.

    PubMed

    Lecordier, Laurence; Uzureau, Pierrick; Tebabi, Patricia; Brauner, Jonathan; Benghiat, Fleur Samantha; Vanhollebeke, Benoit; Pays, Etienne

    2015-08-01

    Human apolipoprotein L1 (APOL1) kills African trypanosomes except Trypanosoma rhodesiense and Trypanosoma gambiense, the parasites causing sleeping sickness. APOL1 uptake into trypanosomes is favoured by its association with the haptoglobin-related protein-haemoglobin complex, which binds to the parasite surface receptor for haptoglobin-haemoglobin. As haptoglobin-haemoglobin can saturate the receptor, APOL1 uptake is increased in haptoglobin-poor (hypohaptoglobinaemic) serum (HyHS). While T. rhodesiense resists APOL1 by RNA polymerase I (pol-I)-mediated expression of the serum resistance-associated (SRA) protein, T. gambiense resists by pol-II-mediated expression of the T. gambiense-specific glycoprotein (TgsGP). Moreover, in T. gambiense resistance to HyHS is linked to haptoglobin-haemoglobin receptor inactivation by mutation. We report that unlike T. gambiense, T. rhodesiense possesses a functional haptoglobin-haemoglobin receptor, and that like T. gambiense experimentally provided with active receptor, this parasite is killed in HyHS because of receptor-mediated APOL1 uptake. However, T. rhodesiense could adapt to low haptoglobin by increasing transcription of SRA. When assayed in Trypanosoma brucei, resistance to HyHS occurred with pol-I-, but not with pol-II-mediated SRA expression. Similarly, T. gambiense provided with active receptor acquired resistance to HyHS only when TgsGP was moved to a pol-I locus. Thus, transcription by pol-I favours adaptive gene regulation, explaining the presence of SRA in a pol-I locus. PMID:25899052

  9. Inheritance and Identification of a Major Quantitative Trait Locus (QTL) that Confers Resistance to Meloidogyne incognita and a Novel QTL for Plant Height in Sweet Sorghum.

    PubMed

    Harris-Shultz, Karen R; Davis, Richard F; Knoll, Joseph E; Anderson, William; Wang, Hongliang

    2015-12-01

    Southern root-knot nematodes (Meloidogyne incognita) are a pest on many economically important row crop and vegetable species and management relies on chemicals, plant resistance, and cultural practices such as crop rotation. Little is known about the inheritance of resistance to M. incognita or the genomic regions associated with resistance in sorghum (Sorghum bicolor). In this study, an F2 population (n = 130) was developed between the resistant sweet sorghum cultivar 'Honey Drip' and the susceptible sweet cultivar 'Collier'. Each F2 plant was phenotyped for stalk weight, height, juice Brix, root weight, total eggs, and eggs per gram of root. Strong correlations were observed between eggs per gram of root and total eggs, height and stalk weight, and between two measurements of Brix. Genotyping-by-sequencing was used to generate single nucleotide polymorphism markers. The G-Model, single marker analysis, interval mapping, and composite interval mapping were used to identify a major quantitative trait locus (QTL) on chromosome 3 for total eggs and eggs per gram of root. Furthermore, a new QTL for plant height was also discovered on chromosome 3. Simple sequence repeat markers were developed in the total eggs and eggs per gram of root QTL region and the markers flanking the resistance gene are 4.7 and 2.4 cM away. These markers can be utilized to move the southern root-knot nematode resistance gene from Honey Drip to any sorghum line. PMID:26574655

  10. Combined linkage and association mapping reveals candidates for Scmv1, a major locus involved in resistance to sugarcane mosaic virus (SCMV) in maize

    PubMed Central

    2013-01-01

    Background Sugarcane mosaic virus (SCMV) disease causes substantial losses of grain yield and forage biomass in susceptible maize cultivars. Maize resistance to SCMV is associated with two dominant genes, Scmv1 and Scmv2, which are located on the short arm of chromosome 6 and near the centromere region of chromosome 3, respectively. We combined both linkage and association mapping to identify positional candidate genes for Scmv1. Results Scmv1 was fine-mapped in a segregating population derived from near-isogenic lines and further validated and fine-mapped using two recombinant inbred line populations. The combined results assigned the Scmv1 locus to a 59.21-kb interval, and candidate genes within this region were predicted based on the publicly available B73 sequence. None of three predicted genes that are possibly involved in the disease resistance response are similar to receptor-like resistance genes. Candidate gene–based association mapping was conducted using a panel of 94 inbred lines with variable resistance to SCMV. A presence/absence variation (PAV) in the Scmv1 region and two polymorphic sites around the Zmtrx-h gene were significantly associated with SCMV resistance. Conclusion Combined linkage and association mapping pinpoints Zmtrx-h as the most likely positional candidate gene for Scmv1. These results pave the way towards cloning of Scmv1 and facilitate marker-assisted selection for potyvirus resistance in maize. PMID:24134222

  11. Construction of a reference linkage map of Vitis amurensis and genetic mapping of Rpv8, a locus conferring resistance to grapevine downy mildew.

    PubMed

    Blasi, Paule; Blanc, Sophie; Wiedemann-Merdinoglu, Sabine; Prado, Emilce; Rühl, Ernst H; Mestre, Pere; Merdinoglu, Didier

    2011-06-01

    Downy mildew, caused by the oomycete Plasmopara viticola, is one of the major threats to grapevine. All traditional cultivars of grapevine (Vitis vinifera) are susceptible to downy mildew, the control of which requires regular application of fungicides. In contrast, many sources of resistance to P. viticola have been described in the Vitis wild species, among which is V. amurensis Rupr. (Vitaceae), a species originating from East Asia. A genetic linkage map of V. amurensis, based on 122 simple sequence repeat and 6 resistance gene analogue markers, was established using S1 progeny. This map covers 975 cM on 19 linkage groups, which represent 82% of the physical coverage of the V. vinifera reference genetic map. To measure the general level of resistance, the sporulation of P. viticola and the necrosis produced in response to infection, five quantitative and semi-quantitative parameters were scored 6 days post-inoculation on the S1 progeny. A quantitative trait locus (QTL) analysis allowed us to identify on linkage group 14 a major QTL controlling the resistance to downy mildew found in V. amurensis, which explained up to 86.3% of the total phenotypic variance. This QTL was named 'Resistance to Plasmopara viticola 8' (Rpv8). PMID:21404060

  12. A reference genetic map of Muscadinia rotundifolia and identification of Ren5, a new major locus for resistance to grapevine powdery mildew.

    PubMed

    Blanc, Sophie; Wiedemann-Merdinoglu, Sabine; Dumas, Vincent; Mestre, Pere; Merdinoglu, Didier

    2012-12-01

    Muscadinia rotundifolia, a species closely related to cultivated grapevine Vitis vinifera, is a major source of resistance to grapevine downy and powdery mildew, two major threats to cultivated traditional cultivars of V. vinifera respectively caused by the oomycete Plasmopara viticola and the ascomycete Erisyphe necator. The aim of the present work was to develop a reference genetic linkage map based on simple sequence repeat (SSR) markers for M. rotundifolia. This map was created using S1 M. rotundifolia cv. Regale progeny, and covers 948 cM on 20 linkage groups, which corresponds to the expected chromosome number for muscadine. The comparison of the genetic maps of V. vinifera and M. rotundifolia revealed a high macrosynteny between the genomes of both species. The S1 progeny was used to assess the general level of resistance of M. rotundifolia to P. viticola and E. necator, by scoring different parameters of pathogen development. A quantitative trait locus (QTL) analysis allowed us to highlight a major QTL on linkage group 14 controlling resistance to powdery mildew, which explained up to 58 % of the total phenotypic variance. This QTL was named 'Resistance to Erysiphe Necator 5' (Ren5). A microscopic evaluation E. necator mycelium development on resistant and susceptible genotypes of the S1 progeny showed that Ren5 exerts its action after the formation of the first appressorium, and acts by delaying, and then stopping, mycelium development. PMID:22865124

  13. Genetic resistance to soybean rust in PI 567099A is at or near the Rpp3 locus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous research identified soybean accession PI 567099A as resistant to soybean rust (SBR). The objective of this research was to map the resistance genes(s) of PI 567099A. A population segregating for SBR resistance was evaluated in the 2008 and 2009 seasons in Paraguay. In both seasons F2:3 f...

  14. NDR1, a locus of Arabidopsis thaliana that is required for disease resistance to both a bacterial and a fungal pathogen.

    PubMed Central

    Century, K S; Holub, E B; Staskawicz, B J

    1995-01-01

    We have employed Arabidopsis thaliana as a model host plant to genetically dissect the molecular pathways leading to disease resistance. A. thaliana accession Col-0 is susceptible to the bacterial pathogen Pseudomonas syringae pv. tomato strain DC3000 but resistant in a race-specific manner to DC3000 carrying any one of the cloned avirulence genes avrB, avrRpm1, avrRpt2, and avrPph3. Fast-neutron-mutagenized Col-0 M2 seed was screened to identify mutants susceptible to DC3000(avrB). Disease assays and analysis of in planta bacterial growth identified one mutant, ndr1-1 (nonrace-specific disease resistance), that was susceptible to DC3000 expressing any one of the four avirulence genes tested. Interestingly, a hypersensitive-like response was still induced by several of the strains. The ndr1-1 mutation also rendered the plant susceptible to several avirulent isolates of the fungal pathogen Peronospora parasitica. Genetic analysis of ndr1-1 demonstrated that the mutation segregated as a single recessive locus, located on chromosome III. Characterization of the ndr1-1 mutation suggests that a common step exists in pathways of resistance to two unrelated pathogens. Images Fig. 1 PMID:11607554

  15. Identification of Stmm3 locus Conferring Resistance to Late-stage Chemically Induced Skin Papillomas on Mouse Chromosome 4 by Congenic Mappingand Allele-specific Alteration Analysis

    PubMed Central

    Saito, Megumi; Okumura, Kazuhiro; Miura, Ikuo; Wakana, Shigeharu; Kominami, Ryo; Wakabayashi, Yuichi

    2014-01-01

    Genome-wide association studies have revealed that many low-penetrance cancer susceptibility loci are located throughout the genome; however, a very limited number of genes have been identified so far. Using a forward genetics approach to map such loci in a mouse skin cancer model, we previously identified strong genetic loci conferring resistance to chemically induced skin papillomas on chromosome 4 and 7 with a large number of [(FVB/N × MSM/Ms) F1 × FVB/N] backcross mice. In this report, we describe a combination of congenic mapping and allele-specific alteration analysis of the loci on chromosome 4. We used linkage analysis and a congenic mouse strain, FVB.MSM-Stmm3 to refine the location of Stmm3 (Skin tumor modifier of MSM 3) locus within a physical interval of about 34 Mb on distal chromosome 4. In addition, we used patterns of allele-specific imbalances in tumors from N2 and N10 congenic mice to narrow down further the region of Stmm3 locus to a physical distance of about 25 Mb. Furthermore, immunohistochemical analysis showed papillomas from congenic mice had less proliferative activity. These results suggest that Stmm3 responsible genes may have an influence on papilloma formation in the two-stage skin carcinogenesis by regulating papilloma growth rather than development. PMID:25077764

  16. Arabidopsis thaliana DM2h (R8) within the Landsberg RPP1-like Resistance Locus Underlies Three Different Cases of EDS1-Conditioned Autoimmunity

    PubMed Central

    Garcia, Ana V.; Wagner, Christine; Choudhury, Sayan R.; Wang, Yiming; James, Geo Velikkakam; Griebel, Thomas; Alcázar, Ruben; Tsuda, Kenichi; Schneeberger, Korbinian; Parker, Jane E.

    2016-01-01

    Plants have a large panel of nucleotide-binding/leucine rich repeat (NLR) immune receptors which monitor host interference by diverse pathogen molecules (effectors) and trigger disease resistance pathways. NLR receptor systems are necessarily under tight control to mitigate the trade-off between induced defenses and growth. Hence, mis-regulated NLRs often cause autoimmunity associated with stunting and, in severe cases, necrosis. Nucleocytoplasmic ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1) is indispensable for effector-triggered and autoimmune responses governed by a family of Toll-Interleukin1-Receptor-related NLR receptors (TNLs). EDS1 operates coincidently or immediately downstream of TNL activation to transcriptionally reprogram cells for defense. We show here that low levels of nuclear-enforced EDS1 are sufficient for pathogen resistance in Arabidopsis thaliana, without causing negative effects. Plants expressing higher nuclear EDS1 amounts have the genetic, phenotypic and transcriptional hallmarks of TNL autoimmunity. In a screen for genetic suppressors of nuclear EDS1 autoimmunity, we map multiple, independent mutations to one gene, DM2h, lying within the polymorphic DANGEROUS MIX2 cluster of TNL RPP1-like genes from A. thaliana accession Landsberg erecta (Ler). The DM2 locus is a known hotspot for deleterious epistatic interactions leading to immune-related incompatibilities between A. thaliana natural accessions. We find that DM2hLer underlies two further genetic incompatibilities involving the RPP1-likeLer locus and EDS1. We conclude that the DM2hLer TNL protein and nuclear EDS1 cooperate, directly or indirectly, to drive cells into an immune response at the expense of growth. A further conclusion is that regulating the available EDS1 nuclear pool is fundamental for maintaining homeostatic control of TNL immune pathways. PMID:27082651

  17. Arabidopsis thaliana DM2h (R8) within the Landsberg RPP1-like Resistance Locus Underlies Three Different Cases of EDS1-Conditioned Autoimmunity.

    PubMed

    Stuttmann, Johannes; Peine, Nora; Garcia, Ana V; Wagner, Christine; Choudhury, Sayan R; Wang, Yiming; James, Geo Velikkakam; Griebel, Thomas; Alcázar, Ruben; Tsuda, Kenichi; Schneeberger, Korbinian; Parker, Jane E

    2016-04-01

    Plants have a large panel of nucleotide-binding/leucine rich repeat (NLR) immune receptors which monitor host interference by diverse pathogen molecules (effectors) and trigger disease resistance pathways. NLR receptor systems are necessarily under tight control to mitigate the trade-off between induced defenses and growth. Hence, mis-regulated NLRs often cause autoimmunity associated with stunting and, in severe cases, necrosis. Nucleocytoplasmic ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1) is indispensable for effector-triggered and autoimmune responses governed by a family of Toll-Interleukin1-Receptor-related NLR receptors (TNLs). EDS1 operates coincidently or immediately downstream of TNL activation to transcriptionally reprogram cells for defense. We show here that low levels of nuclear-enforced EDS1 are sufficient for pathogen resistance in Arabidopsis thaliana, without causing negative effects. Plants expressing higher nuclear EDS1 amounts have the genetic, phenotypic and transcriptional hallmarks of TNL autoimmunity. In a screen for genetic suppressors of nuclear EDS1 autoimmunity, we map multiple, independent mutations to one gene, DM2h, lying within the polymorphic DANGEROUS MIX2 cluster of TNL RPP1-like genes from A. thaliana accession Landsberg erecta (Ler). The DM2 locus is a known hotspot for deleterious epistatic interactions leading to immune-related incompatibilities between A. thaliana natural accessions. We find that DM2hLer underlies two further genetic incompatibilities involving the RPP1-likeLer locus and EDS1. We conclude that the DM2hLer TNL protein and nuclear EDS1 cooperate, directly or indirectly, to drive cells into an immune response at the expense of growth. A further conclusion is that regulating the available EDS1 nuclear pool is fundamental for maintaining homeostatic control of TNL immune pathways. PMID:27082651

  18. The Type 2 Diabetes and Insulin-Resistance Locus Near IRS1 Is A Determinant of HDL Cholesterol and Triglycerides Levels Among Diabetic Subjects

    PubMed Central

    Sharma, Rajani; Prudente, Sabrina; Andreozzi, Francesco; Powers, Christine; Mannino, Gaia; Bacci, Simonetta; Gervino, Ernest V.; Hauser, Thomas H.; Succurro, Elena; Mercuri, Luana; Goheen, Elizabeth H.; Shah, Hetal; Trischitta, Vincenzo; Sesti, Giorgio; Doria, Alessandro

    2011-01-01

    OBJECTIVE SNP rs2943641 near the insulin receptor substrate 1 (IRS1) gene has been found to be associated with type 2 diabetes (T2D) and insulin-resistance in genome-wide association studies. We investigated whether this SNP is associated with cardiovascular risk factors and coronary artery disease (CAD) among diabetic individuals. METHODS SNP rs2943641 was typed in 2,133 White T2D subjects and tested for association with BMI, serum HDL cholesterol and triglycerides, hypertension history, and CAD risk. RESULTS HDL cholesterol decreased by 1 mg/dl (p=0.0045) and serum triglycerides increased by 6 mg/dl (p=0.018) for each copy of the insulin-resistance allele. Despite these effects, no association was found with increased CAD risk (OR=1.00, 95% CI 0.88–1.13). CONCLUSIONS The insulin-resistance and T2D locus near the IRS1 gene is a determinant of lower HDL cholesterol among T2D subjects. However, this effect is small and does not translate into a detectable increase in CAD risk in this population. PMID:21353221

  19. Reniform nematode (Rotylenchulus reniformis) resistance locus from Gossypium aridum identified and introgressed into upland cotton (G. hirsutum)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    SSR markers associated with reniform nematode (Rotylenchulus reniformis) resistance were identified and mapped using progeny from a cross between a tri-species hybrid [Gossypium arboreum × (G 371 - G. hirsutum × G. aridum -)] and G. hirsutum MD51ne. The 50 most resistant and 26 most susceptible prog...

  20. A conserved locus conditioning Soil-borne wheat mosaic virus resistance on 5DL in common wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil-borne wheat mosaic virus (SBWMV) is considered one of the most important diseases in winter wheat regions of the central and southeastern United States. Utilization of resistant cultivars is the only practical and environmentally friendly means of control. To identify QTL for SBWMV resistance, ...

  1. Construction of a genetic map based on high-throughput SNP genotyping and genetic mapping of a TuMV resistance locus in Brassica rapa.

    PubMed

    Chung, Hee; Jeong, Young-Min; Mun, Jeong-Hwan; Lee, Soo-Seong; Chung, Won-Hyong; Yu, Hee-Ju

    2014-04-01

    Brassica rapa is a member of the Brassicaceae family and includes vegetables and oil crops that are cultivated worldwide. The introduction of durable resistance against turnip mosaic virus (TuMV) into agronomically important cultivars has been a significant challenge for genetic and horticultural breeding studies of B. rapa. Based on our previous genome-wide analysis of DNA polymorphisms between the TuMV-resistant doubled haploid (DH) line VC40 and the TuMV-susceptible DH line SR5, we constructed a core genetic map of the VCS-13M DH population, which is composed of 83 individuals derived from microspore cultures of a F1 cross between VC40 and SR5, by analyzing the segregation of 314 sequence-characterized genetic markers. The genetic markers correspond to 221 SNPs and 31 InDels of genes as well as 62 SSRs, covering 1,115.9 cM with an average distance of 3.6 cM between the adjacent marker loci. The alignment and orientation of the constructed map showed good agreement with the draft genome sequence of Chiifu, thus providing an efficient strategy to map genic sequences. Using the genetic map, a novel dominant TuMV resistance locus (TuMV-R) in the VCS-13M DH population was identified as a 0.34 Mb region in the short arm of chromosome A6 in which four CC-NBS-LRR resistance genes and two pathogenesis-related-1 genes reside. The genetic map developed in this study can play an important role in the genetic study of TuMV resistance and the molecular breeding of B. rapa. PMID:24326528

  2. Quantitative trait locus responsible for resistance to Aphanomyces root rot (black root) caused by Aphanomyces cochlioides Drechs. in sugar beet.

    PubMed

    Taguchi, Kazunori; Ogata, Naoki; Kubo, Tomohiko; Kawasaki, Shinji; Mikami, Tetsuo

    2009-01-01

    Aphanomyces root rot, caused by Aphanomyces cochlioides Drechs., is one of the most serious diseases of sugar beet (Beta vulgaris L.). Identification and characterization of resistance genes is a major task in sugar beet breeding. To ensure the effectiveness of marker-assisted screening for Aphanomyces root rot resistance, genetic analysis of mature plants' phenotypic and molecular markers' segregation was carried out. At a highly infested field site, some 187 F(2) and 66 F(3) individuals, derived from a cross between lines 'NK-310mm-O' (highly resistant) and 'NK-184mm-O' (susceptible), were tested, over two seasons, for their level of resistance to Aphanomyces root rot. This resistance was classified into six categories according to the extent and intensity of whole plant symptoms. Simultaneously, two selected RAPD and 159 'NK-310mm-O'-coupled AFLP were used in the construction of a linkage map of 695.7 cM. Each of nine resultant linkage groups was successfully anchored to one of nine sugar beet chromosomes by incorporating 16 STS markers. Combining data for phenotype and molecular marker segregation, a single QTL was identified on chromosome III. This QTL explained 20% of the variance in F(2) population (in the year 2002) and 65% in F(3) lines (2003), indicating that this QTL plays a major role in the Aphanomyces root rot resistance. This is the first report of the genetic mapping of resistance to Aphanomyces-caused diseases in sugar beet. PMID:18813904

  3. The development of a PM3 parameter set to describe iron-sulfur proteins

    NASA Astrophysics Data System (ADS)

    Sundararajan, Mahesh; McNamara, Jonathan P.; Hillier, Ian H.; Wang, Hong; Burton, Neil A.

    2005-03-01

    A PM3 parameter set for iron has been developed, which is appropriate for the active site of iron sulfur proteins having a single iron atom by fitting DFT data obtained for a redox site analogue. These parameters are then tested on a set of such analogues involving a variety of ligands, and show good agreement with both DFT and experimental data for these species. The use of these parameters within a two level ONIOM treatment of the protein rubredoxin, yields accurate predictions of the effect of the enzyme on both Fe-S bond lengths and inner sphere reorganization energies.

  4. THE Bct-1 LOCUS FOR RESISTANCE TO BEET CURLY TOP VIRUS IS ASSOCIATED WITH QUANTITATIVE RESISTANCE TO BEAN DWARF MOSAIC VIRUS IN COMMON BEAN

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Host resistance provides effective control of some diseases induced by geminiviruses in common bean. A recessive gene bgm-1 conditions resistance to Bean golden yellow mosaic virus (BGYMV) and is located on linkage group B3 near the bc-12 gene for resistance to Bean common mosaic virus. The dominan...

  5. Quantitative trait locus mapping and functional genomics of an organophosphate resistance trait in the western corn rootworm, Diabrotica virgifera virgifera

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The western corn rootworm (WCR), Diabrotica virgifera virgifera, is an insect pest of corn, and population suppression with chemical insecticides is an important management tool. Traits conferring organophosphate insecticide resistance have increased in frequency among WCR populations, resulting in...

  6. Effects of Introgression and Recombination on Haplotype Structure and Linkage Disequilibrium Surrounding a Locus Encoding Bymovirus Resistance in Barley

    PubMed Central

    Stracke, Silke; Presterl, Thomas; Stein, Nils; Perovic, Dragan; Ordon, Frank; Graner, Andreas

    2007-01-01

    We present a detailed analysis of linkage disequilibrium (LD) in the physical and genetic context of the barley gene Hv-eIF4E, which confers resistance to the barley yellow mosaic virus (BYMV) complex. Eighty-three SNPs distributed over 132 kb of Hv-eIF4E and six additional fragments genetically mapped to its flanking region were used to derive haplotypes from 131 accessions. Three haplogroups were recognized, discriminating between the alleles rym4 and rym5, which each encode for a spectrum of resistance to BYMV. With increasing map distance, haplotypes of susceptible genotypes displayed diverse patterns driven mainly by recombination, whereas haplotype diversity within the subgroups of resistant genotypes was limited. We conclude that the breakdown of LD within 1 cM of the resistance gene was generated mainly by susceptible genotypes. Despite the LD decay, a significant association between haplotype and resistance to BYMV was detected up to a distance of 5.5 cM from the resistance gene. The LD pattern and the haplotype structure of the target chromosomal region are the result of interplay between low recombination and recent breeding history. PMID:17151251

  7. Duplication of the A17L Locus of Vaccinia Virus Provides an Alternate Route to Rifampin Resistance

    PubMed Central

    Erlandson, Karl J.; Cotter, Catherine A.; Charity, James C.; Martens, Craig; Fischer, Elizabeth R.; Ricklefs, Stacy M.; Porcella, Stephen F.

    2014-01-01

    ABSTRACT Specific gene duplications can enable double-stranded DNA viruses to adapt rapidly to environmental pressures despite the low mutation rate of their high-fidelity DNA polymerases. We report on the rapid positive selection of a novel vaccinia virus genomic duplication mutant in the presence of the assembly inhibitor rifampin. Until now, all known rifampin-resistant vaccinia virus isolates have contained missense mutations in the D13L gene, which encodes a capsid-like scaffold protein required for stabilizing membrane curvature during the early stage of virion assembly. Here we describe a second pathway to rifampin resistance involving A17, a membrane protein that binds and anchors D13 to the immature virion. After one round of selection, a rifampin-resistant virus that contained a genomic duplication in the A17L-A21L region was recovered. The mutant had both C-terminally truncated and full-length A17L open reading frames. Expression of the truncated A17 protein was retained when the virus was passaged in the presence of rifampin but was lost in the absence of the drug, suggesting that the duplication decreased general fitness. Both forms of A17 were bound to the virion membrane and associated with D13. Moreover, insertion of an additional truncated or inducible full-length A17L open reading frame into the genome of the wild-type virus was sufficient to confer rifampin resistance. In summary, this report contains the first evidence of an alternate mechanism for resistance of poxviruses to rifampin, indicates a direct relationship between A17 levels and the resistance phenotype, and provides further evidence of the ability of double-stranded DNA viruses to acquire drug resistance through gene duplication. IMPORTANCE The present study provides the first evidence of a new mechanism of resistance of a poxvirus to the antiviral drug rifampin. In addition, it affirms the importance of the interaction between the D13 scaffold protein and the A17 membrane protein

  8. Genetic evidence for a product of the Fv-1 locus that transfers resistance to mouse leukemia viruses.

    PubMed Central

    Tennant, R W; Schluter, B; Myer, F E; Otten, J A; Yang, W K; Brown, A

    1976-01-01

    Extracts of mouse cells have been shown to transfer to N- or B-trophic host range types of mouse leukemia viruses. The genetic specificity of the inhibition was tested in two ways: (i) by correlating the Fv-1 genotype of a number of mouse strains with the restriction-transferring activity of extracts of the respective embryo cell cultures, and (ii) by correlating the Fv-1 genotype of BLC3F2 (C57BL/6 female [Fv-1bb] by C3H male [Fv-1nn] parental strains) mouse embryos, which segregate the Fv-1 alleles in a 12:1 ratio, with the inhibitor activity of extracts of the cells from each embryo. Five independent matings, totaling 45 individual embryos, were tested. Each embryo was cultured, and the Fv-1 genotype was determined independently by titration of N- and B-tropic viruses; the extracts of replicate secondary cultures were tested for their effect on infection of permissive cells by N- and B-tropic viruses. The specific-restriction-transferring activity of the embryos was found to segregate with the appropriate Fv-1 genotype. These res-lts confirm the suggestion that the inhibitor of the leukemia virus host range types in the cellular extracts is a product of the Fv-1 locus. PMID:186636

  9. Unexpected sequence types in livestock associated methicillin-resistant Staphylococcus aureus (MRSA): MRSA ST9 and a single locus variant of ST9 in pig farming in China.

    PubMed

    Wagenaar, Jaap A; Yue, Hua; Pritchard, Jane; Broekhuizen-Stins, Marian; Huijsdens, Xander; Mevius, Dik J; Bosch, Thijs; Van Duijkeren, Engeline

    2009-11-18

    In October 2008 nine farrow-to-finish pig farms were visited in Shuangliu County in Sichuan Province, China. One farm was empty for one month but not cleaned after depopulation. Dust samples were collected at each farm and analysed for the presence of methicillin-resistant Staphylococcus aureus (MRSA). Dust samples from four farms were also analysed for the presence of methicillin-susceptible S. aureus (MSSA). On 5/9 farms MRSA was isolated and on 2/4 farms MSSA was isolated. On two farms, including the empty farm, no MRSA or MSSA could be detected. All MRSA isolates (n=43) belonged to spa type t899. MSSA isolates belonged to spa type t899 (n=12) and spa type t034 (n=2). From 4/9 farms the MRSA isolates of spa type t899 were assigned to multilocus sequence type (MLST) ST9 whereas on one farm the MRSA spa type t899 isolates belonged to a single locus variant of MLST ST9 (ST1376). MSSA isolates with spa type t899 belonged to MLST ST9 and the MSSA with spa type t034 belonged to MLST ST398. This is the first report on MRSA in pig farms in China and the first time that MRSA ST9 and a single locus variant of ST9 are detected in pig farms. This study shows that livestock associated MRSA is not restricted to clonal lineage ST398 as found in Europe and Northern America in commercial pigs but that other MRSA lineages are able to spread in livestock as well. The study confirms that livestock may act as a reservoir for MRSA. PMID:19608357

  10. Microfluidic-chip-based multiple-locus variable-number tandem-repeat fingerprinting with new primer sets for methicillin-resistant Staphylococcus aureus.

    PubMed

    Sabat, Artur J; Chlebowicz, Monika A; Grundmann, Hajo; Arends, Jan P; Kampinga, Greetje; Meessen, Nico E L; Friedrich, Alexander W; van Dijl, Jan Maarten

    2012-07-01

    The detection of outbreaks of methicillin-resistant Staphylococcus aureus (MRSA) infections and a rapid and accurate identification of sources and routes of transmission should be conducted in hospital settings as early and swiftly as possible. In this study, we investigated the application potential of a new approach based on multiple-locus variable-number tandem-repeat fingerprinting (MLVF) and microfluidics technology for a rapid discrimination of MRSA lineages in outbreak settings. A total of 206 nonrepetitive MRSA isolates recovered from infected patients at the University Medical Center Groningen between 2000 and 2010 were tested. The results obtained by MLVF using microcapillary electrophoresis with newly designed primers were compared to those obtained by spa typing and multiple-locus variable-number tandem-repeat analysis (MLVA). The discriminatory power was 0.980 (107 patterns), 0.969 (85 allelic profiles), and 0.959 (66 types) for MLVF, MLVA, and spa typing, respectively. All methods tested showed a good concordance of results calculated by the adjusted Rand's coefficient method. Comparisons of data obtained by the three approaches allowed us to propose an 88% cutoff value for the similarity between any two MLVF patterns, which can be used in S. aureus epidemiological studies, including analyses of outbreaks and strain transmission events. Of the three tested methods, MLVF is the cheapest, fastest, and easiest to perform. MLVF applied to microfluidic polymer chips is a rapid, cheap, reproducible, and highly discriminating tool to determine the clonality of MRSA isolates and to trace the spread of MRSA strains over periods of many years. Although spa typing should be used due to its portability of data, MLVF has a high added value because it is more discriminatory. PMID:22573591

  11. Mutants resistant to anti-microtubule herbicides map to a locus on the uni linkage group in Chlamydomonas reinhardtii

    SciTech Connect

    James, S.W.; Ranum, L.P.W.; Silflow, C.D.; Lefebvre, P.A.

    1988-01-01

    The authors have used genetic analysis to study the mode of action of two anti-microtubule herbicides, amiprophos-methyl (APM) and oryzaline (ORY). Over 200 resistant mutants were selected by growth on APM- or ORY-containing plates. The 21 independently isolated mutants examined in this study are 3- to 8-fold resistant to APM and are strongly cross-resistant to ORY and butamiphos, a close analog of APM. Two Mendelian genes, apm1 and apm2, are defined by linkage and complementation analysis. There are 20 alleles of apm1 and one temperature-sensitive lethal (33/sup 0/) allele of apm2. Mapping by two-factor crosses places apm1 6.5 cM centromere proximal to uni1 and within 4 cM of pf7 on the uni linkage group, a genetically circular linkage group comprising genes which affect flagellar assembly or function; apm2 maps near the centromere of linkage group VIII. Allele-specific synthetic lethality is observed in crosses between amp2 and alleles of apm1. Also, self crosses of apm2 are zygotic lethal, whereas crosses of nine apm1 alleles inter se result in normal germination and tetrad viability. The mutants are recessive to their wild-type alleles but doubly heterozygous diploids (apm1 +/+ apm2) made with apm2 and any of 15 apm1 alleles display partial intergenic noncomplementation, expressed as intermediate resistance. Diploids homozygous for mutant alleles of apm1 are 4-6-fold resistant to APM and ORY; diploids homozygous for apm2 are ts/sup -/ and 2-fold resistant to the herbicides. From the results described the authors suggest that the gene products of apm1 and apm2 may interact directly or function in the same structure or process.

  12. A single dominant locus Ren4 confers non-race-specific penetration resistance to grapevine powdery mildew.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most powdery mildew resistance genes act after formation of the haustorial feeding cell and secretion of effector proteins into the host epidermis, enabling some degree of hyphal growth. The few genes identified to-date that act to prevent penetration, haustorial formation, and hyphal growth are, w...

  13. Quantitative trait locus analysis of Verticillium wilt resistance in an introgressed recombinant inbred population of Upland cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Verticillium wilt (VW) of Upland cotton (Gossypium hirsutum L.) is caused by the soil-borne fungal pathogen Verticillium dahlia Kleb. The availability of VW-resistant cultivars is vital for control of this economically important disease, but there is a paucity of Upland cotton breeding lines and cul...

  14. Sequence variation at the rice blast resistance gene Pi-km locus: Implications for the development of allele specific markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The recently cloned blast resistance (R) gene Pi-km protects rice crops against specific races of the fungal pathogen Magnaporthe oryzae in a gene-for-gene manner. The use of blast R genes remains the most cost-effective method for an integrated disease management strategy. To facilitate rice breed...

  15. FaRXf1: a locus conferring resistance to angular leaf spot caused by Xanthomonas fragariae in octoploid strawberry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Angular leaf spot caused by Xanthomonas fragariae is the only major bacterial disease of cultivated strawberry (Fragaria ×ananassa). While this disease may cause reductions of up to 8 % of marketable yield in Florida winter annual production, no resistant cultivars have been commercialized. Wild acc...

  16. Fine Mapping and Isolation of Rmc1(blb)Locus to Columbia Root-Knot Nematode Resistance from Solanum bulbocastanum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Columbia root-knot nematode (Meloidogyne chitwoodi) causes a severe disease on potato in the Northwest of the US and other parts of the World. The natural resistance has been discovered in several wild potato species, Solanum bulbocastanum, S. hougasii and S. fendleri, endemic to Mexico and the ...

  17. Resistance locus pyramids alter transcript abundance in soybean roots inoculated with Fusarium solani f.sp. glycines.

    PubMed

    Iqbal, M J; Yaegashi, S; Njiti, V N; Ahsan, R; Cryder, K L; Lightfoot, D A

    2002-11-01

    Soybean Sudden Death Syndrome (SDS) is caused by Fusarium solani f.sp. glycines (Fsg). Six quantitative trait loci (QTLs), each conferring partial resistance to SDS, have been discovered in an Essex x Forrest recombinant inbred line (RIL) population, but their mode of action is not clear. This study aimed to identify genes (ESTs) whose mRNA transcripts were altered in abundance in soybean roots following inoculation of Fsg. Roots of the soybean variety Forrest (four resistance alleles) were inoculated with Fsg, and 14 days later RNA sequences that were differentially expressed relative to uninoculated roots were enriched using suppression subtraction and differential display. The abundance of these RNAs was quantified in inoculated and non-inoculated roots by macroarray hybridizations. A unigene set of 135 ESTs was identified and used in a further macroarray analysis. The abundance of 28 cDNA fragments was increased more than two-fold in inoculated compared to uninoculated roots of RIL 23 (six resistance alleles). In Forrest and Essex (two resistance alleles), the level of only one mRNA was increased two-fold in inoculated roots compared to the uninoculated roots. In Essex most of the mRNAs analyzed decreased in abundance (61/135 showed a two-fold decrease), while in Forrest most mRNA abundances did not change. Among the 28 cDNAs that revealed a two-fold or higher increase in mRNA abundance in RIL 23, 14% code for proteins known to be involved in plant defense, 21% in metabolism, 14% in cell structure and 4% in transport. Unannotated ESTs accounted for 43% of the genes, and 4% of the sequences were previously unknown. The plant defense-related genes that showed a differential response to Fsg inoculation suggested a role for the phenylproponoid pathway in soybean defense against Fsg. In Essex, genes involved in plant defense, cell wall synthesis, ethylene synthesis and metabolism were expressed at lower levels in inoculated roots. The difference in response between

  18. The Cmv1 host resistance locus is closely linked to the Ly49 multigene family within the natural killer cell gene complex on mouse chromosome 6

    SciTech Connect

    Forbes, C.A.; Shellam, G.R.; Scalzo, A.A.

    1997-05-01

    Natural killer (NK) cells play important roles in controlling tumor cells and against a range of infectious organisms. Recent studies of mouse NK cell surface receptors, which may be involved in the specificity of NK cells, have shown that many of these molecules are encoded by the Ly49 and Ly55 (Nkrp1) multigene families that map to distal mouse chromosome 6. Also mapping to this NK cell gene complex (NKC) is the resistance locus, Cmv1, which is involved in genetically determined resistance to murine cytomegalovirus (MCMV). The aim of this study was to localize Cmv1 more precisely in relation to other NKC loci by generating a high-resolution genetic map of the region. We have analyzed 1250 backcross mice comprising panels of 700 (BALB/c x C57BL/6J)F{sub 1} X BALB/c and 550 (A/J X C57BL/6J)F{sub 1} X A/J progeny. A total of 25 polymorphic genes or microsatellite markers were analyzed over a region of 10 map units from D6Mit134 to D6Mit59. The Cmv1 phenotypes of mice recombinant in this interval were tested by infection with MCMV. The results obtained indicate that the functionally important NKC region is a tightly linked cluster of loci spanning at least 0.4 map units. Furthermore, Cmv1 maps distal to, but very closely linked to, the Ly49 multigene family (< 0.2 map units), suggesting that MCMV resistance may be conferred by MHC class I-specific NK cell receptors. 49 refs., 4 figs., 1 tab.

  19. Applications of the PM3 semi-empirical method to the study of triethylenediamine.

    PubMed

    Mancuso, J; McEachern, R J

    1997-04-01

    Charcoal filters impregnated with triethylenediamine (TEDA) are known to be efficient for the collection of volatile methyl iodide, which may be released under a hypothetical loss-of-coolant accident in a nuclear generating station. The structure and thermodynamic stability of the products of the TEDA-methyl iodide reaction have thus been studied using semi-empirical techniques. The reaction of TEDA with two molecules of methyl iodide leads to a quaternization reaction at each of the nitrogens. Moreover, it is shown that substitution of the hydrogens on TEDA with electron-donating groups can lead to enhanced stability of the quaternary ammonium reaction products. The semi-empirical method PM3 (Parametric Method 3) was used as the basis for all calculations. Molecular systems and simulations were constructed using HyperChem 4.5 for Silicon Graphics workstations. Enthalpy determination and geometry optimization were some of the calculations performed on a system. PMID:9385556

  20. Genetic dissection of a TIR-NB-LRR locus from the wild North American grapevine species Muscadinia rotundifolia identifies paralogous genes conferring resistance to major fungal and oomycete pathogens in cultivated grapevine.

    PubMed

    Feechan, Angela; Anderson, Claire; Torregrosa, Laurent; Jermakow, Angelica; Mestre, Pere; Wiedemann-Merdinoglu, Sabine; Merdinoglu, Didier; Walker, Amanda R; Cadle-Davidson, Lance; Reisch, Bruce; Aubourg, Sebastien; Bentahar, Nadia; Shrestha, Bipna; Bouquet, Alain; Adam-Blondon, Anne-Françoise; Thomas, Mark R; Dry, Ian B

    2013-11-01

    The most economically important diseases of grapevine cultivation worldwide are caused by the fungal pathogen powdery mildew (Erysiphe necator syn. Uncinula necator) and the oomycete pathogen downy mildew (Plasmopara viticola). Currently, grapegrowers rely heavily on the use of agrochemicals to minimize the potentially devastating impact of these pathogens on grape yield and quality. The wild North American grapevine species Muscadinia rotundifolia was recognized as early as 1889 to be resistant to both powdery and downy mildew. We have now mapped resistance to these two mildew pathogens in M. rotundifolia to a single locus on chromosome 12 that contains a family of seven TIR-NB-LRR genes. We further demonstrate that two highly homologous (86% amino acid identity) members of this gene family confer strong resistance to these unrelated pathogens following genetic transformation into susceptible Vitis vinifera winegrape cultivars. These two genes, designated resistance to Uncinula necator (MrRUN1) and resistance to Plasmopara viticola (MrRPV1) are the first resistance genes to be cloned from a grapevine species. Both MrRUN1 and MrRPV1 were found to confer resistance to multiple powdery and downy mildew isolates from France, North America and Australia; however, a single powdery mildew isolate collected from the south-eastern region of North America, to which M. rotundifolia is native, was capable of breaking MrRUN1-mediated resistance. Comparisons of gene organization and coding sequences between M. rotundifolia and the cultivated grapevine V. vinifera at the MrRUN1/MrRPV1 locus revealed a high level of synteny, suggesting that the TIR-NB-LRR genes at this locus share a common ancestor. PMID:24033846

  1. Role of Arabidopsis UV RESISTANCE LOCUS 8 in plant growth reduction under osmotic stress and low levels of UV-B.

    PubMed

    Fasano, Rossella; Gonzalez, Nathalie; Tosco, Alessandra; Dal Piaz, Fabrizio; Docimo, Teresa; Serrano, Ramon; Grillo, Stefania; Leone, Antonella; Inzé, Dirk

    2014-05-01

    In high-light environments, plants are exposed to different types of stresses, such as an excess of UV-B, but also drought stress which triggers a common morphogenic adaptive response resulting in a general reduction of plant growth. Here, we report that the Arabidopsis thaliana UV RESISTANCE LOCUS 8 (UVR8) gene, a known regulator of the UV-B morphogenic response, was able to complement a Saccharomyces cerevisiae osmo-sensitive mutant and its expression was induced after osmotic or salt stress in Arabidopsis plants. Under low levels of UV-B, plants overexpressing UVR8 are dwarfed with a reduced root development and accumulate more flavonoids compared to control plants. The growth defects are mainly due to the inhibition of cell expansion. The growth inhibition triggered by UVR8 overexpression in plants under low levels of UV-B was exacerbated by mannitol-induced osmotic stress, but it was not significantly affected by ionic stress. In contrast, uvr8-6 mutant plants do not differ from wild-type plants under standard conditions, but they show an increased shoot growth under high-salt stress. Our data suggest that UVR8-mediated accumulation of flavonoid and possibly changes in auxin homeostasis are the underlying mechanism of the observed growth phenotypes and that UVR8 might have an important role for integrating plant growth and stress signals. PMID:24413416

  2. Multiple Roles for UV RESISTANCE LOCUS8 in Regulating Gene Expression and Metabolite Accumulation in Arabidopsis under Solar Ultraviolet Radiation1[W][OA

    PubMed Central

    Morales, Luis O.; Brosché, Mikael; Vainonen, Julia; Jenkins, Gareth I.; Wargent, Jason J.; Sipari, Nina; Strid, Åke; Lindfors, Anders V.; Tegelberg, Riitta; Aphalo, Pedro J.

    2013-01-01

    Photomorphogenic responses triggered by low fluence rates of ultraviolet B radiation (UV-B; 280–315 nm) are mediated by the UV-B photoreceptor UV RESISTANCE LOCUS8 (UVR8). Beyond our understanding of the molecular mechanisms of UV-B perception by UVR8, there is still limited information on how the UVR8 pathway functions under natural sunlight. Here, wild-type Arabidopsis (Arabidopsis thaliana) and the uvr8-2 mutant were used in an experiment outdoors where UV-A (315–400 nm) and UV-B irradiances were attenuated using plastic films. Gene expression, PYRIDOXINE BIOSYNTHESIS1 (PDX1) accumulation, and leaf metabolite signatures were analyzed. The results show that UVR8 is required for transcript accumulation of genes involved in UV protection, oxidative stress, hormone signal transduction, and defense against herbivores under solar UV. Under natural UV-A irradiance, UVR8 is likely to interact with UV-A/blue light signaling pathways to moderate UV-B-driven transcript and PDX1 accumulation. UVR8 both positively and negatively affects UV-A-regulated gene expression and metabolite accumulation but is required for the UV-B induction of phenolics. Moreover, UVR8-dependent UV-B acclimation during the early stages of plant development may enhance normal growth under long-term exposure to solar UV. PMID:23250626

  3. High-resolution melting analysis of the spa locus reveals significant diversity within sequence type 93 methicillin-resistant Staphylococcus aureus from northern Australia.

    PubMed

    Tong, S Y C; Lilliebridge, R A; Holt, D C; McDonald, M I; Currie, B J; Giffard, P M

    2009-12-01

    High-resolution melting analysis is an inherently robust, easy and inexpensive approach to the examination of genomic regions containing single-nucleotide polymorphisms and hypervariable loci. Staphylococcus aureus sequence type (ST) 93 is a singleton, Panton-Valentine leukocidin-positive clone unique to Australia. A high-resolution melting-based method for the identification of ST93 was developed, and a similar approach was used to reveal diversity within the spa locus of this lineage. Statistical and graphical methods that account for instrumental and operator-dependent variation in high-resolution melting curves were developed, to allow greater confidence and reproducibility in deciding whether another curve is truly different from the baseline curve of an amplicon with known sequence. The data support a very early acquisition, or multiple independent acquisitions, of SCCmec by ST93 methicillin-susceptible S. aureus (MSSA), and the coexistence of MSSA and methicillin-resistant S. aureus versions of the same lineage within northern Australia. PMID:19392885

  4. A 1,681-locus consensus genetic map of cultivated cucumber including 67 NB-LRR resistance gene homolog and ten gene loci

    PubMed Central

    2013-01-01

    Background Cucumber is an important vegetable crop that is susceptible to many pathogens, but no disease resistance (R) genes have been cloned. The availability of whole genome sequences provides an excellent opportunity for systematic identification and characterization of the nucleotide binding and leucine-rich repeat (NB-LRR) type R gene homolog (RGH) sequences in the genome. Cucumber has a very narrow genetic base making it difficult to construct high-density genetic maps. Development of a consensus map by synthesizing information from multiple segregating populations is a method of choice to increase marker density. As such, the objectives of the present study were to identify and characterize NB-LRR type RGHs, and to develop a high-density, integrated cucumber genetic-physical map anchored with RGH loci. Results From the Gy14 draft genome, 70 NB-containing RGHs were identified and characterized. Most RGHs were in clusters with uneven distribution across seven chromosomes. In silico analysis indicated that all 70 RGHs had EST support for gene expression. Phylogenetic analysis classified 58 RGHs into two clades: CNL and TNL. Comparative analysis revealed high-degree sequence homology and synteny in chromosomal locations of these RGH members between the cucumber and melon genomes. Fifty-four molecular markers were developed to delimit 67 of the 70 RGHs, which were integrated into a genetic map through linkage analysis. A 1,681-locus cucumber consensus map including 10 gene loci and spanning 730.0 cM in seven linkage groups was developed by integrating three component maps with a bin-mapping strategy. Physically, 308 scaffolds with 193.2 Mbp total DNA sequences were anchored onto this consensus map that covered 52.6% of the 367 Mbp cucumber genome. Conclusions Cucumber contains relatively few NB-LRR RGHs that are clustered and unevenly distributed in the genome. All RGHs seem to be transcribed and shared significant sequence homology and synteny with the melon

  5. Sparkle/PM3 Parameters for the Modeling of Neodymium(III), Promethium(III), and Samarium(III) Complexes.

    PubMed

    Freire, Ricardo O; da Costa, Nivan B; Rocha, Gerd B; Simas, Alfredo M

    2007-07-01

    The Sparkle/PM3 model is extended to neodymium(III), promethium(III), and samarium(III) complexes. The unsigned mean error, for all Sparkle/PM3 interatomic distances between the trivalent lanthanide ion and the ligand atoms of the first sphere of coordination, is 0.074 Å for Nd(III); 0.057 Å for Pm(III); and 0.075 Å for Sm(III). These figures are similar to the Sparkle/AM1 ones of 0.076 Å, 0.059 Å, and 0.075 Å, respectively, indicating they are all comparable models. Moreover, their accuracy is similar to what can be obtained by present-day ab initio effective potential calculations on such lanthanide complexes. Hence, the choice of which model to utilize will depend on the assessment of the effect of either AM1 or PM3 on the quantum chemical description of the organic ligands. Finally, we present a preliminary attempt to verify the geometry prediction consistency of Sparkle/PM3. Since lanthanide complexes are usually flexible, we randomly generated 200 different input geometries for the samarium complex QIPQOV which were then fully optimized by Sparkle/PM3. A trend appeared in that, on average, the lower the total energy of the local minima found, the lower the unsigned mean errors, and the higher the accuracy of the model. These preliminary results do indicate that attempting to find, with Sparkle/PM3, a global minimum for the geometry of a given complex, with the understanding that it will tend to be closer to the experimental geometry, appears to be warranted. Therefore, the sparkle model is seemingly a trustworthy semiempirical quantum chemical model for the prediction of lanthanide complexes geometries. PMID:26633229

  6. PM3 semi-empirical IR spectra simulations for metal complexes of schiff bases of sulfa drugs

    NASA Astrophysics Data System (ADS)

    Topacli, C.; Topacli, A.

    2003-06-01

    The molecular structures and infrared spectra of Co, Ni, Cu and Zn complexes of two schiff base ligands, viz N-( o-vanillinidene)sulfanilamide ( oVSaH) and N-( o-vanillinidene)sulfamerazine ( oVSmrzH) are studied in detail by PM3 method. It has been shown that the proposed structures for the compounds derived from microanalytical, magnetic and various spectral data were consistent with the IR spectra simulated by PM3 method. Coordination effects on ν(CN) and ν(C-O) modes in the schiff base ligands are in close agreement with the observed results.

  7. Applicability of PM3 to transphosphorylation reaction path: Toward designing a minimal ribozyme

    NASA Technical Reports Server (NTRS)

    Manchester, John I.; Shibata, Masayuki; Setlik, Robert F.; Ornstein, Rick L.; Rein, Robert

    1993-01-01

    A growing body of evidence shows that RNA can catalyze many of the reactions necessary both for replication of genetic material and the possible transition into the modern protein-based world. However, contemporary ribozymes are too large to have self-assembled from a prebiotic oligonucleotide pool. Still, it is likely that the major features of the earliest ribozymes have been preserved as molecular fossils in the catalytic RNA of today. Therefore, the search for a minimal ribozyme has been aimed at finding the necessary structural features of a modern ribozyme (Beaudry and Joyce, 1990). Both a three-dimensional model and quantum chemical calculations are required to quantitatively determine the effects of structural features of the ribozyme on the reaction it catalyzes. Using this model, quantum chemical calculations must be performed to determine quantitatively the effects of structural features on catalysis. Previous studies of the reaction path have been conducted at the ab initio level, but these methods are limited to small models due to enormous computational requirements. Semiempirical methods have been applied to large systems in the past; however, the accuracy of these methods depends largely on a simple model of the ribozyme-catalyzed reaction, or hydrolysis of phosphoric acid. We find that the results are qualitatively similar to ab initio results using large basis sets. Therefore, PM3 is suitable for studying the reaction path of the ribozyme-catalyzed reaction.

  8. The cyclophilin CYP20-2 modulates the conformation of BRASSINAZOLE-RESISTANT1, which binds the promoter of FLOWERING LOCUS D to regulate flowering in Arabidopsis.

    PubMed

    Zhang, Yuanyuan; Li, Beibei; Xu, Yunyuan; Li, Heng; Li, Shanshan; Zhang, Dajian; Mao, Zhiwei; Guo, Siyi; Yang, Chunhong; Weng, Yuxiang; Chong, Kang

    2013-07-01

    Brassinosteroids (BRs) regulate many physiological processes during plant development, including flowering. However, little is known about the components of BR signaling that mediate flowering. Here, we report that BRASSINAZOLE-RESISTANT1 (BZR1), the conformation of which is altered by a cyclophilin (CYP20-2), binds cis-elements in the FLOWERING LOCUS D (FLD) promoter to regulate flowering. Both bzr1-1D and fld-4 showed delayed flowering. Electrophoretic mobility shift assay and chromatin immunoprecipitation revealed that BZR1 bound to a putative BR response cis-element and suppressed the expression of FLD. Overexpression of FLD partially rescued the late flowering of pBZR1:mBZR1(Pro234-Leu)-CFP (mx3). Yeast two-hybrid and pull-down assays demonstrated that BZR1 interacts with CYP20-2. Arabidopsis thaliana CYP20-2 had greater peptidyl-prolyl cis-trans isomerase activity than did wheat (Triticum aestivum) CYP20-2. Fourier transform infrared spectroscopy revealed conformation changes in BZR1, dependent on interaction with CYP20-2. Due to differences in activity and substrate preference between CYP20-2 proteins from wheat and Arabidopsis, At-CYP20-2-overexpressing lines showed earlier flowering, whereas Ta CYP20-2 lines flowered later. Immunoblot and chromatin immunoprecipitation assays showed that histone H3 trimethyl Lys4 and H3 acetylation levels were negatively correlated with the transcription of FLD (a putative histone demethylase) in various lines. Therefore, a conformational change of BZR1 mediated by CYP20-2 causes altered flowering through modulation of FLD expression. PMID:23897924

  9. The Bcg/Ity/Lsh locus: genetic transfer of resistance to infections in C57BL/6J mice transgenic for the Nramp1 Gly169 allele.

    PubMed Central

    Govoni, G; Vidal, S; Gauthier, S; Skamene, E; Malo, D; Gros, P

    1996-01-01

    The murine Bcg/Ity/Lsh locus determines the susceptibilities of inbred strains to infection with unrelated intracellular parasites, such as Mycobacterium bovis, Salmonella typhimurium, and Leishmania donovani. A candidate for Bcg/Ity/Lsh, designated Nramp1, has been recently identified and shown to encode a novel integral membrane protein that is expressed exclusively in professional phagocytes but whose function remains unknown. In inbred strains, the susceptibility to infection is associated with a single glycine-to-aspartic acid substitution at position 169 (G169D) in the predicted TM4 of the protein. To confirm the candidacy of Nramp1 as Bcg/Ity/Lsh and to determine the importance of the G169D mutation on Nramp1 function, we constructed transgenic mice in which the G169 allele of Nramp1 was transferred onto the background of a homozygous D169 allele. These transgenic mice were analyzed for their sensitivity to infections under the control of Bcg/Ity/Lsh. The transgene constructed for these studies contained the entire Nramp1G169 gene together with approximately 5 kb of sequences upstream of the transcription initiation site of this gene. We observed that these sequences were sufficient to direct Nramp1G169 expression in transgenic macrophages, resulting in the appearance of a mature protein of 90 to 100 kDa over a background of Nramp1G169 characterized by the complete absence of the mature Nramp1 polypeptide. The appearance of the Nramp1G169-encoded protein in transgenic macrophages was concomitant with the emergence of resistance to infection by M. bovis BCG, as measured by the extent of bacteria] replication in the spleen, and by S. typhimurium, as measured by survival after an intravenous challenge. The gain of function detected in transgenic Nramp1G169 animals establishes unambiguously that Nramp1 and Bcg/Ity/Lsh are allelic. PMID:8757814

  10. Hydrogen peroxide, nitric oxide and UV RESISTANCE LOCUS8 interact to mediate UV-B-induced anthocyanin biosynthesis in radish sprouts

    PubMed Central

    Wu, Qi; Su, Nana; Zhang, Xiaoyan; Liu, Yuanyuan; Cui, Jin; Liang, Yongchao

    2016-01-01

    The cross talk among hydrogen peroxide (H2O2), nitric oxide (NO) and UV RESISTANCE LOCUS8 (UVR8) in UV-B-induced anthocyanin accumulation in the hypocotyls of radish sprouts was investigated. The results showed that UV-B irradiation significantly increased the anthocyanin accumulation and the expression of UVR8, and a similar trend appeared in radish sprouts subjected to cadmium, chilling and salt stresses regardless of light source. However, these responses disappeared under dark exposure. These results suggest that abiotic stress-induced anthocyanin accumulation and UVR8 expression were light-dependent. Moreover, abiotic stresses all enhanced the production of H2O2 and exogenous H2O2 addition significantly increased the anthocyanin concentration and UVR8 transcription, while these increases were severely inhibited by addition of dimethylthiourea (DMTU, a chemical trap for H2O2). It seems to suggest that H2O2 played an important role in the anthocyanin biosynthesis. Furthermore, addition of 0.5 mM sodium nitroprusside (SNP, a NO-releasing compound) substantially induced the anthocyanin accumulation, and H2O2-induced anthocyanin accumulation and UVR8 expression were significantly suppressed by co-treatment with 2-phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl (PTIO, a NO scavenger), which was parallel with the expression of anthocyanin biosynthesis-related transcription factors and structural genes. All these results demonstrate that both H2O2 and NO are involved in UV-B-induced anthocyanin accumulation, and there is a crosstalk between them as well as a classical UVR8 pathway. PMID:27404993

  11. Hydrogen peroxide, nitric oxide and UV RESISTANCE LOCUS8 interact to mediate UV-B-induced anthocyanin biosynthesis in radish sprouts.

    PubMed

    Wu, Qi; Su, Nana; Zhang, Xiaoyan; Liu, Yuanyuan; Cui, Jin; Liang, Yongchao

    2016-01-01

    The cross talk among hydrogen peroxide (H2O2), nitric oxide (NO) and UV RESISTANCE LOCUS8 (UVR8) in UV-B-induced anthocyanin accumulation in the hypocotyls of radish sprouts was investigated. The results showed that UV-B irradiation significantly increased the anthocyanin accumulation and the expression of UVR8, and a similar trend appeared in radish sprouts subjected to cadmium, chilling and salt stresses regardless of light source. However, these responses disappeared under dark exposure. These results suggest that abiotic stress-induced anthocyanin accumulation and UVR8 expression were light-dependent. Moreover, abiotic stresses all enhanced the production of H2O2 and exogenous H2O2 addition significantly increased the anthocyanin concentration and UVR8 transcription, while these increases were severely inhibited by addition of dimethylthiourea (DMTU, a chemical trap for H2O2). It seems to suggest that H2O2 played an important role in the anthocyanin biosynthesis. Furthermore, addition of 0.5 mM sodium nitroprusside (SNP, a NO-releasing compound) substantially induced the anthocyanin accumulation, and H2O2-induced anthocyanin accumulation and UVR8 expression were significantly suppressed by co-treatment with 2-phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl (PTIO, a NO scavenger), which was parallel with the expression of anthocyanin biosynthesis-related transcription factors and structural genes. All these results demonstrate that both H2O2 and NO are involved in UV-B-induced anthocyanin accumulation, and there is a crosstalk between them as well as a classical UVR8 pathway. PMID:27404993

  12. Identification of a Rice stripe necrosis virus resistance locus and yield component QTLs using Oryza sativa × O. glaberrima introgression lines

    PubMed Central

    2010-01-01

    Background Developing new population types based on interspecific introgressions has been suggested by several authors to facilitate the discovery of novel allelic sources for traits of agronomic importance. Chromosome segment substitution lines from interspecific crosses represent a powerful and useful genetic resource for QTL detection and breeding programs. Results We built a set of 64 chromosome segment substitution lines carrying contiguous chromosomal segments of African rice Oryza glaberrima MG12 (acc. IRGC103544) in the genetic background of Oryza sativa ssp. tropical japonica (cv. Caiapó). Well-distributed simple-sequence repeats markers were used to characterize the introgression events. Average size of the substituted chromosomal segments in the substitution lines was about 10 cM and covered the whole donor genome, except for small regions on chromosome 2 and 4. Proportions of recurrent and donor genome in the substitution lines were 87.59% and 7.64%, respectively. The remaining 4.78% corresponded to heterozygotes and missing data. Strong segregation distortion was found on chromosomes 3 and 6, indicating the presence of interspecific sterility genes. To illustrate the advantages and the power of quantitative trait loci (QTL) detection using substitution lines, a QTL detection was performed for scored traits. Transgressive segregation was observed for several traits measured in the population. Fourteen QTLs for plant height, tiller number per plant, panicle length, sterility percentage, 1000-grain weight and grain yield were located on chromosomes 1, 3, 4, 6 and 9. Furthermore, a highly significant QTL controlling resistance to the Rice stripe necrosis virus was located between SSR markers RM202-RM26406 (44.5-44.8 cM) on chromosome 11. Conclusions Development and phenotyping of CSSL libraries with entire genome coverage represents a useful strategy for QTL discovery. Mapping of the RSNV locus represents the first identification of a genetic factor

  13. Prediction for thermodynamic function of dioxins for gas phase using semi-empirical molecular orbital method with PM3 Hamiltonian.

    PubMed

    Saito, N; Fuwa, A

    2000-01-01

    In this investigation, respective thermodynamic parameters of heats of formation, standard entropy and specific heat capacity at constant pressure for PCDDs, PCDFs, Co-PCB and PCBs as well as polychlorinated-benzenes and polychlorinated-phenols have been evaluated by quantum chemical calculation using a semi-empirical molecular orbital method with the PM3 Hamiltonian and statistical thermodynamic correlation. PMID:10665426

  14. A high-resolution map of the Grp1 locus on chromosome V of potato harbouring broad-spectrum resistance to the cyst nematode species Globodera pallida and Globodera rostochiensis.

    PubMed

    Finkers-Tomczak, Anna; Danan, Sarah; van Dijk, Thijs; Beyene, Amelework; Bouwman, Liesbeth; Overmars, Hein; van Eck, Herman; Goverse, Aska; Bakker, Jaap; Bakker, Erin

    2009-06-01

    The Grp1 locus confers broad-spectrum resistance to the potato cyst nematode species Globodera pallida and Globodera rostochiensis and is located in the GP21-GP179 interval on the short arm of chromosome V of potato. A high-resolution map has been developed using the diploid mapping population RHAM026, comprising 1,536 genotypes. The flanking markers GP21 and GP179 have been used to screen the 1,536 genotypes for recombination events. Interval mapping of the resistances to G. pallida Pa2 and G. rostochiensis Ro5 resulted in two nearly identical LOD graphs with the highest LOD score just north of marker TG432. Detailed analysis of the 44 recombinant genotypes showed that G. pallida and G. rostochiensis resistance could not be separated and map to the same location between marker SPUD838 and TG432. It is suggested that the quantitative resistance to both nematode species at the Grp1 locus is mediated by one or more tightly linked R genes that might belong to the NBS-LRR class. PMID:19363662

  15. Molecular cloning and functional analysis of a UV-B photoreceptor gene, MdUVR8 (UV Resistance Locus 8), from apple.

    PubMed

    Zhao, Cheng; Mao, Ke; You, Chun-Xiang; Zhao, Xian-Yan; Wang, Shu-Hui; Li, Yuan-Yuan; Hao, Yu-Jin

    2016-06-01

    UVR8 (UV Resistance Locus 8) is an ultraviolet-B (UV-B; 280-315nm) light receptor that is involved in regulating many aspects of plant growth and development. UV-B irradiation can increase the development of flower and fruit coloration in many fruit trees, such as grape, pear and apple. Previous investigations of the structure and functions of UVR8 in plants have largely focused on Arabidopsis. Here, we isolated the UVR8 gene from apple (Malus domestica) and analyzed its function in transgenic Arabidopsis. Genomic and protein sequence analysis showed that MdUVR8 shares high similarity with the AtUVR8 protein from Arabidopsis, including the conserved seven-bladed β-propeller, the C27 region, the 3 "GWRHT" motifs and crucial amino-acid residues (14 Trps, 2 Args). A point mutation prediction and three-dimensional structural analysis of MdUVR8 indicated that it has a similar structure to AtUVR8 and that the crucial residues are also important in MdUVR8. In terms of transcript levels, MdUVR8 expression was up-regulated by UV-B light, which suggests that its expression follows a 24-h circadian rhythm. Using heterologous expression of MdUVR8 in both uvr8-1 mutant and wild-type (WT) Arabidopsis, we found that MdUVR8 regulates hypocotyl elongation and gene expression under UV-B light. These data provide functional evidence for a role of MdUVR8 in controlling photomorphogenesis under UV-B light and indicate that the function of UVR8 is conserved between Arabidopsis and apple. Furthermore, we examined the interaction between MdUVR8 and MdCOP1 (constitutive photomorphogenic1) using a yeast two-hybrid assay and a co-immunoprecipitation assay. This interaction provides a direction for investigating the regulatory mechanisms of the UV-B-light pathway in apple. PMID:27095405

  16. ICESluvan, a 94-Kilobase Mosaic Integrative Conjugative Element Conferring Interspecies Transfer of VanB-Type Glycopeptide Resistance, a Novel Bacitracin Resistance Locus, and a Toxin-Antitoxin Stabilization System

    PubMed Central

    Bjørkeng, Eva K.; Hjerde, Erik; Pedersen, Torunn; Sundsfjord, Arnfinn

    2013-01-01

    A 94-kb integrative conjugative element (ICESluvan) transferable to Enterococcus faecium and Enterococcus faecalis from an animal isolate of Streptococcus lutetiensis consists of a mosaic of genetic fragments from different Gram-positive bacteria. A variant of ICESluvan was confirmed in S. lutetiensis from a patient. A complete Tn5382/Tn1549 with a vanB2 operon is integrated into a streptococcal ICESde3396-like region harboring a putative bacteriophage exclusion system, a putative agglutinin receptor precursor, and key components of a type IV secretion system. Moreover, ICESluvan encodes a putative MobC family mobilization protein and a relaxase and, thus, in total has all genetic components essential for conjugative transfer. A 9-kb element within Tn5382/Tn1549 encodes, among others, putative proteins similar to the TnpX site-specific recombinase in Faecalibacterium and VanZ in Paenibacillus, which may contribute to the detected low-level teicoplanin resistance. Furthermore, ICESluvan encodes a novel bacitracin resistance locus that is associated with reduced susceptibility to bacitracin when transferred to E. faecium. The expression of a streptococcal pezAT toxin-antitoxin-encoding operon of ICESluvan in S. lutetiensis, E. faecium, and E. faecalis was confirmed by reverse transcription (RT)-PCR, indicating an active toxin-antitoxin system which may contribute to stabilizing ICESluvan within new hosts. Junction PCR and DNA sequencing confirmed that ICESluvan excised to form a circular intermediate in S. lutetiensis, E. faecalis, and E. faecium. Transfer between E. faecalis cells was observed in the presence of helper plasmid pIP964. Sequence analysis of the original S. lutetiensis donor and enterococcal transconjugants showed that ICESluvan integrates in a site-specific manner into the C-terminal end of the chromosomal tRNA methyltransferase gene rumA. PMID:24078615

  17. The wheat Phs-A1 pre-harvest sprouting resistance locus delays the rate of seed dormancy loss and maps 0.3 cM distal to the PM19 genes in UK germplasm.

    PubMed

    Shorinola, Oluwaseyi; Bird, Nicholas; Simmonds, James; Berry, Simon; Henriksson, Tina; Jack, Peter; Werner, Peter; Gerjets, Tanja; Scholefield, Duncan; Balcárková, Barbara; Valárik, Miroslav; Holdsworth, M J; Flintham, John; Uauy, Cristobal

    2016-07-01

    The precocious germination of cereal grains before harvest, also known as pre-harvest sprouting, is an important source of yield and quality loss in cereal production. Pre-harvest sprouting is a complex grain defect and is becoming an increasing challenge due to changing climate patterns. Resistance to sprouting is multi-genic, although a significant proportion of the sprouting variation in modern wheat cultivars is controlled by a few major quantitative trait loci, including Phs-A1 in chromosome arm 4AL. Despite its importance, little is known about the physiological basis and the gene(s) underlying this important locus. In this study, we characterized Phs-A1 and show that it confers resistance to sprouting damage by affecting the rate of dormancy loss during dry seed after-ripening. We show Phs-A1 to be effective even when seeds develop at low temperature (13 °C). Comparative analysis of syntenic Phs-A1 intervals in wheat and Brachypodium uncovered ten orthologous genes, including the Plasma Membrane 19 genes (PM19-A1 and PM19-A2) previously proposed as the main candidates for this locus. However, high-resolution fine-mapping in two bi-parental UK mapping populations delimited Phs-A1 to an interval 0.3 cM distal to the PM19 genes. This study suggests the possibility that more than one causal gene underlies this major pre-harvest sprouting locus. The information and resources reported in this study will help test this hypothesis across a wider set of germplasm and will be of importance for breeding more sprouting resilient wheat varieties. PMID:27217549

  18. Genome-Wide Scan and Test of Candidate Genes in the Snail Biomphalaria glabrata Reveal New Locus Influencing Resistance to Schistosoma mansoni

    PubMed Central

    Tennessen, Jacob A.; Bonner, Kaitlin M.; Bollmann, Stephanie R.; Johnstun, Joel A.; Yeh, Jan-Ying; Marine, Melanie; Tavalire, Hannah F.; Bayne, Christopher J.; Blouin, Michael S.

    2015-01-01

    Background New strategies to combat the global scourge of schistosomiasis may be revealed by increased understanding of the mechanisms by which the obligate snail host can resist the schistosome parasite. However, few molecular markers linked to resistance have been identified and characterized in snails. Methodology/Principal Findings Here we test six independent genetic loci for their influence on resistance to Schistosoma mansoni strain PR1 in the 13-16-R1 strain of the snail Biomphalaria glabrata. We first identify a genomic region, RADres, showing the highest differentiation between susceptible and resistant inbred lines among 1611 informative restriction-site associated DNA (RAD) markers, and show that it significantly influences resistance in an independent set of 439 outbred snails. The additive effect of each RADres resistance allele is 2-fold, similar to that of the previously identified resistance gene sod1. The data fit a model in which both loci contribute independently and additively to resistance, such that the odds of infection in homozygotes for the resistance alleles at both loci (13% infected) is 16-fold lower than the odds of infection in snails without any resistance alleles (70% infected). Genome-wide linkage disequilibrium is high, with both sod1 and RADres residing on haplotype blocks >2Mb, and with other markers in each block also showing significant effects on resistance; thus the causal genes within these blocks remain to be demonstrated. Other candidate loci had no effect on resistance, including the Guadeloupe Resistance Complex and three genes (aif, infPhox, and prx1) with immunological roles and expression patterns tied to resistance, which must therefore be trans-regulated. Conclusions/Significance The loci RADres and sod1 both have strong effects on resistance to S. mansoni. Future approaches to control schistosomiasis may benefit from further efforts to characterize and harness this natural genetic variation. PMID:26372103

  19. Structural, Electronic and Qsar Properties of the Cyfluthrin Molecule:. a Theoretical AM1 and PM3 Treatment

    NASA Astrophysics Data System (ADS)

    Çalişir, Emine Deniz; Erkoç, Şakir

    Cyfluthrin is a synthetic cyano-containing pyrethroid insecticide that has both contact and stomach poison action. It is a nonsystemic chemical used to control cutworms, ants, silverfish, cockroaches, mosquitoes, tobacco budworm and many others. Its primary agricultural uses have been for control of chewing and sucking insects on crops such as cotton, turf, ornamentals, hops, cereal, corn, deciduous fruit, peanuts, potatoes, and other vegetables. Cyfluthrin is also used in public health situations and for structural pest control. The structural, vibrational, electronic and QSAR properties of the cyfluthrin molecule in gas phase have been investigated theoretically by performing molecular mechanics method by using MM+ force field, and semi-empirical molecular orbital AM1 and PM3 calculations. The geometry of the molecule has been optimized, infrared spectrum (vibrational modes and intensities) and the electronic properties of the molecule have been calculated in its ground state. According to PM3 calculation, heat of formation of cyfluthrin molecule is about -48.58 kcal/mol (exothermic), which shows that this molecule thermodynamically be stable. The HOMO energy level for this molecule is found to be -9.701 eV and the LUMO energy level is -0.660 eV giving rise to a gap of 9.041 eV, which also indicates that cyfluthrin is thermodynamically stable.

  20. NMR structure of rALF-Pm3, an anti-lipopolysaccharide factor from shrimp: model of the possible lipid A-binding site.

    PubMed

    Yang, Yinshan; Boze, Hélène; Chemardin, Patrick; Padilla, André; Moulin, Guy; Tassanakajon, Anchalee; Pugnière, Martine; Roquet, Françoise; Destoumieux-Garzón, Delphine; Gueguen, Yannick; Bachère, Evelyne; Aumelas, André

    2009-03-01

    The anti-lipopolysaccharide factor ALF-Pm3 is a 98-residue protein identified in hemocytes from the black tiger shrimp Penaeus monodon. It was expressed in Pichia pastoris from the constitutive glyceraldehyde-3-phosphate dehydrogenase promoter as a folded and (15)N uniformly labeled rALF-Pm3 protein. Its 3D structure was established by NMR and consists of three alpha-helices packed against a four-stranded beta-sheet. The C(34)-C(55) disulfide bond was shown to be essential for the structure stability. By using surface plasmon resonance, we demonstrated that rALF-Pm3 binds to LPS, lipid A and to OM-174, a soluble analogue of lipid A. Biophysical studies of rALF-Pm3/LPS and rALF-Pm3/OM-174 complexes indicated rather high molecular sized aggregates, which prevented us to experimentally determine by NMR the binding mode of these lipids to rALF-Pm3. However, on the basis of striking structural similarities to the FhuA/LPS complex, we designed an original model of the possible lipid A-binding site of ALF-Pm3. Such a binding site, located on the ALF-Pm3 beta-sheet and involving seven charged residues, is well conserved in ALF-L from Limulus polyphemus and in ALF-T from Tachypleus tridentatus. In addition, our model is in agreement with experiments showing that beta-hairpin synthetic peptides corresponding to ALF-L beta-sheet bind to LPS. Delineating lipid A-binding site of ALFs will help go further in the de novo design of new antibacterial or LPS-neutralizing drugs. PMID:19107926

  1. Mapping of a stem rust resistance locus effective against Ug99 on wheat chromosome 7AL using a RAD-Seq approach

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat stem rust is responsible for major production losses around the world. The development of resistant cultivars is an effective way to manage the disease, but outbreaks can occur when new pathogen races overcome the existing resistances. Ug99 (race TTKSK), and related newly-emerged, highly virul...

  2. CAPS markers in an eIF4E gene are linked to Zucchini yellow mosaic virus resistant locus in watermelon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zucchini yellow mosaic virus (ZYMV) is an economically important virus infecting cucurbits worldwide. Genetic sources of resistance to ZYMV have been identified in wild watermelon germplasm where a single recessive gene (zym) confers ZYMV resistance. Marker-assisted selection (MAS) would greatly fa...

  3. Relationship between Yield Components and Partial Resistance to Lecanicillium fungicola in the Button Mushroom, Agaricus bisporus, Assessed by Quantitative Trait Locus Mapping

    PubMed Central

    Rodier, Anne; Savoie, Jean-Michel

    2012-01-01

    Dry bubble, caused by Lecanicillium fungicola, is one of the most detrimental diseases affecting button mushroom cultivation. In a previous study, we demonstrated that breeding for resistance to this pathogen is quite challenging due to its quantitative inheritance. A second-generation hybrid progeny derived from an intervarietal cross between a wild strain and a commercial cultivar was characterized for L. fungicola resistance under artificial inoculation in three independent experiments. Analysis of quantitative trait loci (QTL) was used to determine the locations, numbers, and effects of genomic regions associated with dry-bubble resistance. Four traits related to resistance were analyzed. Two to four QTL were detected per trait, depending on the experiment. Two genomic regions, on linkage group X (LGX) and LGVIII, were consistently detected in the three experiments. The genomic region on LGX was detected for three of the four variables studied. The total phenotypic variance accounted for by all QTL ranged from 19.3% to 42.1% over all traits in all experiments. For most of the QTL, the favorable allele for resistance came from the wild parent, but for some QTL, the allele that contributed to a higher level of resistance was carried by the cultivar. Comparative mapping with QTL for yield-related traits revealed five colocations between resistance and yield component loci, suggesting that the resistance results from both genetic factors and fitness expression. The consequences for mushroom breeding programs are discussed. PMID:22247161

  4. Bulk Segregate Analysis using the GoldenGate Assay to Locate the Rpp3 Locus that Confers Resistance to Phakopsora pachyrhizi (Soybean Rust) in Soybean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Few resistance genes to soybean rust (SBR), caused by Phakopsora pachyrhizi Syd., have been genetically mapped and linked to molecular markers that can be used for marker assisted selection. New technologies are available for SNP genotyping that can be used to rapidly map single gene resistance to ...

  5. The Nematode Resistance Allele at the rhg1 Locus Alters the Proteome and Primary Metabolism of Soybean Roots1[C][W][OA

    PubMed Central

    Afzal, Ahmed J.; Natarajan, Aparna; Saini, Navinder; Iqbal, M. Javed; Geisler, Matt; El Shemy, Hany A.; Mungur, Rajsree; Willmitzer, Lothar; Lightfoot, David A.

    2009-01-01

    Heterodera glycines, the soybean cyst nematode (SCN), causes the most damaging chronic disease of soybean (Glycine max). Host resistance requires the resistance allele at rhg1. Resistance destroys the giant cells created in the plant's roots by the nematodes about 24 to 48 h after commencement of feeding. In addition, 4 to 8 d later, a systemic acquired resistance develops that discourages later infestations. The molecular mechanisms that control the rhg1-mediated resistance response appear to be multigenic and complex, as judged by transcript abundance changes, even in near isogenic lines (NILs). This study aimed to focus on key posttranscriptional changes by identifying proteins and metabolites that were increased in abundance in both resistant and susceptible NILs. Comparisons were made among NILs 10 d after SCN infestation and without SCN infestation. Two-dimensional gel electrophoresis resolved more than 1,000 protein spots on each gel. Only 30 protein spots with a significant (P < 0.05) difference in abundance of 1.5-fold or more were found among the four treatments. The proteins in these spots were picked, trypsin digested, and analyzed using quadrupole time-of-flight tandem mass spectrometry. Protein identifications could be made for 24 of the 30 spots. Four spots contained two proteins, so that 28 distinct proteins were identified. The proteins were grouped into six functional categories. Metabolite analysis by gas chromatography-mass spectrometry identified 131 metabolites, among which 58 were altered by one or more treatment; 28 were involved in primary metabolism. Taken together, the data showed that 17 pathways were altered by the rhg1 alleles. Pathways altered were associated with systemic acquired resistance-like responses, including xenobiotic, phytoalexin, ascorbate, and inositol metabolism, as well as primary metabolisms like amino acid synthesis and glycolysis. The pathways impacted by the rhg1 allelic state and SCN infestation agreed with

  6. Tan spot susceptibility governed by the Tsn1 locus and race-nonspecific resistance quantitative trait loci in a population derived from the wheat lines Salamouni and Katepwa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat-tan spot interactions are known to have an inverse gene-for-gene relationship where pathogen-produced necrotrophic effectors are recognized by host sensitivity genes to cause susceptibility. However, broad-spectrum non race-specific resistance quantitative trait loci (QTL) that do not conform...

  7. Barley Germplasm STARS-9577B lacks a Russian Wheat Aphid Resistance Allele at a Quantitative Trait Locus Present in STARS-9301B

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Russian wheat aphid (RWA, Diuraphis noxia Kurdjumov) infestations of barley (Hordeum vulgare L.) in the western U.S.A. have reduced yield and quality of barley since its introduction in 1986. Resistant germplasm lines have been released and used for cultivar development, including ‘STARS-9577B’, a s...

  8. Quantitative trait locus mapping for Verticillium wilt resistance in a backcross inbred line population of cotton (Gossypium hirsutum × Gossypium barbadense) based on RGA-AFLP analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Verticillium wilt (VW), caused by Verticillium dahliae, is one of the most important diseases in cotton. Development and growing of VW resistant cultivars is the most effective and economic strategy in controlling the disease. However, little is currently known on the genetic basis of VW resistanc...

  9. Identification and Genomic Location of a Reniform Nematode (Rotylenchulus reniformis) Resistance locus (Ren_ari) Introgressed from Gossypium aridum into Upland Cotton (G. hirsutum)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this association mapping study, a tri-species hybrid, [G. arboreum × (G. hirsutum × G aridum)], was crossed with MD51ne (G. hirsutum) and progeny from the cross were used to identify and map SSR markers associated with reniform nematode (Rotylenchulus reniformis) resistance. Seventy six progeny ...

  10. Cloning and function validation of a nb-arc-lrr-type candidate gene for the greenbug aphid resistance locus, Gb3, in wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The greenbug, Schizaphis graminum, is one of the most important aphid pests of small grain crops in many parts of the world. A single dominant gene, Gb3 originated from Aegilops tauschii has shown consistent and durable resistance against prevailing greenbug biotypes in wheat fields. A fine genetic ...

  11. Identification of a candidate gene for the wheat endopeptidase Ep-D1 locus and two other STS markers linked to the eyespot resistance gene Pch1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat is prone to strawbreaker foot rot (eye- spot), a fungal disease caused by Oculimacula yallundae and O. acuformis. The most effective source of genetic resistance is Pch1, a gene derived from Aegilops ventri- cosa. The endopeptidase isozyme marker allele Ep-D1b, linked to Pch1, has been shown t...

  12. Evolution of New Disease Specificity at a Single Resistance Locus in a Crop-Weed Complex: Reconstitution of the Lr21 Gene in Wheat.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leaf-rust resistance gene Lr21, present in modern varieties of hexaploid wheat, originated in goatgrass Aegilops tauschii Coss., the D genome donor of wheat. The goatgrass donor was collected in Iran where it grows as a weed in wheat fields as part of the native agricultural ecosystem. In order to ...

  13. Identification of a CAPS marker in an eIF4E gene Linked to Zucchini yellow mosaic virus resistant locus in watermelon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genes that encode eukaryotic initiation factors (eIF) 4E and iso(4E) have been associated with the recessively inherited resistance to potyviruses in a number of plant species. Using previously developed degenerate primers, partial eIF4E and eIF(iso)4E gene sequence regions were obtained through po...

  14. Fate of Mutation Rate Depends on agr Locus Expression during Oxacillin-Mediated Heterogeneous-Homogeneous Selection in Methicillin-Resistant Staphylococcus aureus Clinical Strains ▿ †

    PubMed Central

    Plata, Konrad B.; Rosato, Roberto R.; Rosato, Adriana E.

    2011-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) strains are characterized by a heterogeneous expression of resistance. We have previously shown in clinical oxacillin-susceptible, mecA-positive MRSA strains that selection from a very heterogeneous (HeR) to highly homogeneous (HoR) resistant phenotype was mediated by acquisition of mutations through an oxacillin-induced SOS response. In the present study, we used a spotted DNA microarray to evaluate differential gene expression during HeR-HoR selection and found increased expression of the agr two-component regulatory system. We hypothesized that increased expression of agr represents a mechanistically relevant component of this process. We demonstrated that inactivation of agr during the HeR-HoR selection process results in a significant increase in mutation rate; these effects were reversed by complementing the agr mutant. Furthermore, we found that extemporal ectopic expression of agr and, more specifically, RNAII in agr-null mutant HeR cells suppressed mutation frequency and the capacity of these cells to undergo the HeR-HoR selection. These findings sustain the concept that increased expression of agr during HeR-HoR selection plays a critical role in regulating the β-lactam-induced increased mutation rate in very heterogeneous MRSA strains. Moreover, they indicate that a temporally controlled increase in agr expression is required to tightly modulate SOS-mediated mutation rates, which then allows for full expression of oxacillin homogeneous resistance in very heterogeneous clinical MRSA strains. PMID:21537016

  15. GpaXI ( tar ) ( l ) originating from Solanum tarijense is a major resistance locus to Globodera pallida and is localised on chromosome 11 of potato.

    PubMed

    Adillah Tan, M Y; Park, Tae-Ho; Alles, René; Hutten, Ronald C B; Visser, R G F; van Eck, Herman J

    2009-11-01

    Resistance to Globodera pallida Rookmaker (Pa3), originating from wild species Solanum tarijense was identified by QTL analysis and can be largely ascribed to one major QTL. GpaXI ( tar ) ( l ) explained 81.3% of the phenotypic variance in the disease test. GpaXI ( tar ) ( l ) is mapped to the long arm of chromosome 11. Another minor QTL explained 5.3% of the phenotypic variance and mapped to the long arm of chromosome 9. Clones containing both QTL showed no lower cyst counts than clones with only GpaXI ( tar ) ( l ) . After Mendelising the phenotypic data, GpaXI ( tar ) ( l ) could be more precisely mapped near markers GP163 and FEN427, thus anchoring GpaXI ( tar ) ( l ) to a region with a known R-gene cluster containing virus and nematode resistance genes. PMID:19816672

  16. Genetic Analysis Using an Isogenic Mating Pair of Aspergillus fumigatus Identifies Azole Resistance Genes and Lack of MAT Locus's Role in Virulence.

    PubMed

    Losada, Liliana; Sugui, Janyce A; Eckhaus, Michael A; Chang, Yun C; Mounaud, Stephanie; Figat, Abigail; Joardar, Vinita; Pakala, Suman B; Pakala, Suchitra; Venepally, Pratap; Fedorova, Natalie; Nierman, William C; Kwon-Chung, Kyung J

    2015-04-01

    Invasive aspergillosis (IA) due to Aspergillus fumigatus is a major cause of mortality in immunocompromised patients. The discovery of highly fertile strains of A. fumigatus opened the possibility to merge classical and contemporary genetics to address key questions about this pathogen. The merger involves sexual recombination, selection of desired traits, and genomics to identify any associated loci. We constructed a highly fertile isogenic pair of A. fumigatus strains with opposite mating types and used them to investigate whether mating type is associated with virulence and to find the genetic loci involved in azole resistance. The pair was made isogenic by 9 successive backcross cycles of the foundational strain AFB62 (MAT1-1) with a highly fertile (MAT1-2) progeny. Genome sequencing showed that the F9 MAT1-2 progeny was essentially identical to the AFB62. The survival curves of animals infected with either strain in three different animal models showed no significant difference, suggesting that virulence in A. fumigatus was not associated with mating type. We then employed a relatively inexpensive, yet highly powerful strategy to identify genomic loci associated with azole resistance. We used traditional in vitro drug selection accompanied by classical sexual crosses of azole-sensitive with resistant isogenic strains. The offspring were plated under varying drug concentrations and pools of resulting colonies were analyzed by whole genome sequencing. We found that variants in 5 genes contributed to azole resistance, including mutations in erg11A (cyp51A), as well as multi-drug transporters, erg25, and in HMG-CoA reductase. The results demonstrated that with minimal investment into the sequencing of three pools from a cross of interest, the variation(s) that contribute any phenotype can be identified with nucleotide resolution. This approach can be applied to multiple areas of interest in A. fumigatus or other heterothallic pathogens, especially for virulence

  17. Cytological and molecular characterization of quantitative trait locus qRfg1, which confers resistance to gibberella stalk rot in maize.

    PubMed

    Ye, Jianrong; Guo, Yanling; Zhang, Dongfeng; Zhang, Nan; Wang, Chao; Xu, Mingliang

    2013-12-01

    Tremendous progress has been made recently in understanding plant response to Fusarium graminearum infection. Here, the cytological aspect and molecular mechanism of maize defense to F. graminearum infection were characterized using a pair of near-isogenic lines (NIL), the resistant and the susceptible NIL. F. graminearum primarily penetrated the maize root tip and no penetration structure was found. The fungal biomass within the root correlated well with root-disease severity. Following inoculation, R-NIL and S-NIL plants significantly differed in percentage of diseased primary roots. In R-NIL roots, a fraction of exodermal cells collapsed to form cavities, and hyphae were confined to the outer exodermal cells. However, most exodermal cells shrank and turned brown, and fungi colonized the entire S-NIL root. In the R-NIL roots, the exodermal cells exhibited plasmolysis and atropous hyphal growth whereas, in the exodermal cells of the S-NIL roots, severe cellular degradation and membrane-coated, lushly grown hyphae were found. Transcriptome sequencing revealed comprehensive transcription reprogramming, reinforcement of a complex defense network, to enhance the systemic and basal resistance. This study reports a detailed microscopic analysis of F. graminearum infection on maize root, and provides insights into the molecular mechanisms underlying maize resistance to the pathogen. PMID:23902264

  18. Putrescine production via the ornithine decarboxylation pathway improves the acid stress survival of Lactobacillus brevis and is part of a horizontally transferred acid resistance locus.

    PubMed

    Romano, Andrea; Ladero, Victor; Alvarez, Miguel A; Lucas, Patrick M

    2014-04-01

    Decarboxylation pathways are widespread among lactic acid bacteria; their physiological role is related to acid resistance through the regulation of the intracellular pH and to the production of metabolic energy via the generation of a proton motive force and its conversion into ATP. These pathways include, among others, biogenic amine (BA) production pathways. BA accumulation in foodstuffs is a health risk; thus, the study of the factors involved in their production is of major concern. The analysis of several lactic acid bacterial strains isolated from different environments, including fermented foods and beverages, revealed that the genes encoding these pathways are clustered on the chromosome, which suggests that these genes are part of a genetic hotspot related to acid stress resistance. Further attention was devoted to the ornithine decarboxylase pathway, which affords putrescine from ornithine. Studies were performed on three lactic acid bacteria belonging to different species. The ODC pathway was always shown to be involved in cytosolic pH alkalinisation and acid shock survival, which were observed to occur with a concomitant increase in putrescine production. PMID:24495587

  19. Sequence Analysis of a 282-Kilobase Region Surrounding the Citrus Tristeza Virus Resistance Gene (Ctv) Locus in Poncirus trifoliata L. Raf.1

    PubMed Central

    Yang, Zhong-Nan; Ye, Xin-Rong; Molina, Joe; Roose, Mikeal L.; Mirkov, T. Erik

    2003-01-01

    Citrus tristeza virus (CTV) is the major virus pathogen causing significant economic damage to citrus worldwide, and a single dominant gene, Ctv, provides broad spectrum resistance to CTV in Poncirus trifoliata L. Raf. Ctv was physically mapped to a 282-kb region using a P. trifoliata bacterial artificial chromosome library. This region was completely sequenced to about 8× coverage using a shotgun sequencing strategy and primer walking for gap closure. Sequence analysis predicts 22 putative genes, two mutator-like transposons and eight retrotransposons. This sequence analysis also revealed some interesting features of this region of the P. trifoliata genome: a disease resistance gene cluster with seven members and eight retrotransposons clustered in a 125-kb gene-poor region. Comparative sequence analysis suggests that six genes in the Ctv region have significant sequence similarity with their orthologs in bacterial artificial chromosome clones F7H2 and F21T11 from Arabidopsis chromosome I. However, the analysis of gene colinearity between P. trifoliata and Arabidopsis indicates that Arabidopsis genome sequence information may be of limited use for positional gene cloning in P. trifoliata and citrus. Analysis of candidate genes for Ctv is also discussed. PMID:12586873

  20. Sequence analysis of a 282-kilobase region surrounding the citrus Tristeza virus resistance gene (Ctv) locus in Poncirus trifoliata L. Raf.

    PubMed

    Yang, Zhong-Nan; Ye, Xin-Rong; Molina, Joe; Roose, Mikeal L; Mirkov, T Erik

    2003-02-01

    Citrus tristeza virus (CTV) is the major virus pathogen causing significant economic damage to citrus worldwide, and a single dominant gene, Ctv, provides broad spectrum resistance to CTV in Poncirus trifoliata L. Raf. Ctv was physically mapped to a 282-kb region using a P. trifoliata bacterial artificial chromosome library. This region was completely sequenced to about 8x coverage using a shotgun sequencing strategy and primer walking for gap closure. Sequence analysis predicts 22 putative genes, two mutator-like transposons and eight retrotransposons. This sequence analysis also revealed some interesting features of this region of the P. trifoliata genome: a disease resistance gene cluster with seven members and eight retrotransposons clustered in a 125-kb gene-poor region. Comparative sequence analysis suggests that six genes in the Ctv region have significant sequence similarity with their orthologs in bacterial artificial chromosome clones F7H2 and F21T11 from Arabidopsis chromosome I. However, the analysis of gene colinearity between P. trifoliata and Arabidopsis indicates that Arabidopsis genome sequence information may be of limited use for positional gene cloning in P. trifoliata and citrus. Analysis of candidate genes for Ctv is also discussed. PMID:12586873

  1. Emergence of a multidrug-resistant (ASSuTTm) strain of Salmonella enterica serovar Typhimurium DT120 in England in 2011 and the use of multiple-locus variable-number tandem-repeat analysis in supporting outbreak investigations.

    PubMed

    Paranthaman, Karthikeyan; Haroon, Sophie; Latif, Samia; Vinnyey, Natalie; de Souza, Valerie; Welfare, William; Tahir, Mamoona; Cooke, Edward; Stone, Kirsten; Lane, Chris; Peters, Tansy; Puleston, Richard

    2013-10-01

    In summer 2011, two outbreaks of a unique, multidrug-resistant strain of Salmonella enterica serovar Typhimurium phage type 120 (DT120) occurred mainly in the Midlands, England. The first outbreak occurred among guests attending a wedding in July 2011 ('Wedding outbreak'), followed by a more geographically dispersed outbreak in August and September 2011 ('Midlands outbreak'). Fifty-one cases were confirmed. Detailed epidemiological and environmental health investigations suggested that pork was the most likely source of both outbreaks. All human samples and one pork sample showed the specific multiple-locus variable-number tandem-repeat analysis (MLVA) profile 3-11-12-NA-0211, with at most two loci variations. Trace-back investigations suggested a link to a butcher's shop and a pig farm in the East Midlands. The investigations highlight the utility of molecular analysis (MLVA) in supporting epidemiological investigations of outbreaks caused by S. Typhimurium DT120. Safe handling and cooking of pork by food business operators and consumers are key interventions to prevent future outbreaks. PMID:23869962

  2. Targeted introduction of a diphtheria toxin resistant mutation into the chromosomal EF-2 locus of Pichia pastoris and expression of immunotoxin in the EF-2 mutants.

    PubMed

    Liu, Yuan Yi; Woo, Jung Hee; Neville, David M

    2003-08-01

    In an attempt to increase the production of a diphtheria toxin (DT) based immunotoxin by Pichia pastoris, we have created DT-resistant mutants that contain a substitution of arginine for glycine at position 701 in elongation factor 2 (EF-2). To achieve this, we first cloned and characterized the EF-2 gene (PEF1), and then made a construct pBLURA-Delta5'mutEF-2 that efficiently introduces specific mutations into the chromosomal EF-2 gene in P. pastoris by in vivo homologous recombination. pBLURA-Delta5(')mutEF-2 contains a selection marker URA3 and a 5' truncated form of the P. pastoris PEF1 that had been modified in vitro to carry the nucleotide mutations for the Gly(701) to Arg transition. Unlike the non-mutated strains, the EF-2 mutants are resistant to high-level intracellular expression of DT A chain that can catalyze the ADP-ribosylation. When used to express the secreted bivalent anti-T cell immunotoxin, A-dmDT390-bisFv(G4S), the EF-2 mutant strains showed increased viability compared to the non-mutated strains. However, they did not show an advantage over the non-mutated expressing strain in the production of the immunotoxin. Western blotting analysis revealed that although the EF-2 mutants did not increase the accumulation of intact A-dmDT390-bisFv(G4S) in the culture medium, they generated larger amounts of degraded products found in both the medium and cell pellets compared to the non-mutant expressing clone. In addition, double copy expression resulted in greater amounts of intact immunotoxin being retained within cellular compartments as well as degraded products. Based on these findings, we suggest that the secretory capacity may be rate limiting for divalent immunotoxin production in P. pastoris. PMID:12880776

  3. MpeR regulates the mtr efflux locus in Neisseria gonorrhoeae and modulates antimicrobial resistance by an iron-responsive mechanism.

    PubMed

    Mercante, Alexandra Dubon; Jackson, Lydgia; Johnson, Paul J T; Stringer, Virginia A; Dyer, David W; Shafer, William M

    2012-03-01

    Previous studies have shown that the MpeR transcriptional regulator produced by Neisseria gonorrhoeae represses the expression of mtrF, which encodes a putative inner membrane protein (MtrF). MtrF works as an accessory protein with the Mtr efflux pump, helping gonococci to resist high levels of diverse hydrophobic antimicrobials. Regulation of mpeR has been reported to occur by an iron-dependent mechanism involving Fur (ferric uptake regulator). Collectively, these observations suggest the presence of an interconnected regulatory system in gonococci that modulates the expression of efflux pump protein-encoding genes in an iron-responsive manner. Herein, we describe this connection and report that levels of gonococcal resistance to a substrate of the mtrCDE-encoded efflux pump can be modulated by MpeR and the availability of free iron. Using microarray analysis, we found that the mtrR gene, which encodes a direct repressor (MtrR) of mtrCDE, is an MpeR-repressed determinant in the late logarithmic phase of growth when free iron levels would be reduced due to bacterial consumption. This repression was enhanced under conditions of iron limitation and resulted in increased expression of the mtrCDE efflux pump operon. Furthermore, as judged by DNA-binding analysis, MpeR-mediated repression of mtrR was direct. Collectively, our results indicate that both genetic and physiologic parameters (e.g., iron availability) can influence the expression of the mtr efflux system and modulate levels of gonococcal susceptibility to efflux pump substrates. PMID:22214775

  4. The IGF2 Locus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insulin-like growth factor 2 (IGF2) is a peptide hormone regulating various cellular processes such as proliferation and apoptosis. IGF2 is vital to embryo development. The IGF2 locus covers approximately 150-kb genomic region on human chromosome 11, containing two imprinted genes, IGF2 and H19, sha...

  5. Molecular analysis of the mouse agouti gene and the role of dominant agouti-locus mutations in obesity and insulin resistance

    SciTech Connect

    Klebig, M.L.; Woychik, R.P.; Wilkinson, J.E.

    1994-09-01

    The lethal yellow (A{sup y/-}) and viable yellow (A{sup vy/-}) mouse agouti mutants have a predominantly yellow pelage and display a complex syndrome that includes obesity, hyperinsulinemia, and insulin resistance, hallmark features of obesity-associated noninsulin-dependent diabetes mellitus (NIDDM) in humans. A new dominant agouti allele, A{sup iapy}, has recently been identified; like the A{sup vy} allele, it is homozygous viable and confers obesity and yellow fur in heterozygotes. The agouti gene was cloned and characterized at the molecular level. The gene is expressed in the skin during hair growth and is predicted to encode a 131 amino acid protein, that is likely to be a secreted factor. In both Ay/- and A{sup iapy}/- mice, the obesity and other dominant pleiotropic effects are associated with an ectopic expression of agouti in many tissues where the gene product is normally not produced. In Ay, a 170-kb deletion has occurred that causes an upstream promoter to drive the ectopic expression of the wild-type agouti coding exons. In A{sup iapy}, the coding region of the gene is expressed from a cryptic promoter within the LTR of an intracisternal A-particle (IAP), which has integrated within the region just upstream of the first agouti coding exon. Transgenic mice ubiquitously expressing the cloned agouti gene under the influence of the beta-actin and phosphoglycerate kinase promoters display obesity, hyperinsulinemia, and yellow coat color. This demonstrates unequivocally that ectopic expression of agouti is responsible for the yellow obese syndrome.

  6. Locus equations are an acoustic expression of articulator synergy

    PubMed Central

    Iskarous, Khalil; Fowler, Carol A.; Whalen, D. H.

    2010-01-01

    The study investigated the articulatory basis of locus equations, regression lines relating F2 at the start of a Consonant-Vowel (CV) transition to F2 at the middle of the vowel, with C fixed and V varying. Several studies have shown that consonants of different places of articulation have locus equation slopes that descend from labial to velar to alveolar, and intercept magnitudes that increase in the opposite order. Using formulas from the theory of bivariate regression that express regression slopes and intercepts in terms of standard deviations and averages of the variables, it is shown that the slope directly encodes a well-established measure of coarticulation resistance. It is also shown that intercepts are directly related to the degree to which the tongue body assists the formation of the constriction for the consonant. Moreover, it is shown that the linearity of locus equations and the linear relation between locus equation slopes and intercepts originates in linearity in articulation between the horizontal position of the tongue dorsum in the consonant and to that in the vowel. It is concluded that slopes and intercepts of acoustic locus equations are measures of articulator synergy. PMID:20968373

  7. Ecology, Behavior and Bionomics: First Genotyping of Spodoptera frugiperda (J. E. Smith)(Lepidoptera: Noctuidae) Progeny from Crosses between Bt-Resistant and Bt-Susceptible Populations, and 65-Locus Discrimination of Isofami

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Simple sequence repeat (SSR) markers from Spodoptera frugiperda (J. E. Smith) were analyzed in crosses of this species between Bacillus thuringiensis (Berliner) (Bacillales: Bacillaceae) (Bt) resistant and susceptible populations to determine a possible association between markers and Bt resistance....

  8. Chromosomal locus for staphylococcal enterotoxin B.

    PubMed Central

    Shafer, W M; Iandolo, J J

    1978-01-01

    The genetic locus of staphylococcal enterotoxin B (SEB) was investigated in the Staphylococcus aureus food-poisoning isolates, strains S6 and 277. Direct neutral sucrose gradient centrifugation analysis of sodium dodecyl sulfate-sodium chloride-mediated cleared lysates demonstrated that strain S6 contained a single 37S plasmid. Transductional analysis revealed that the 37S plasmid in S6 encoded for cadmium resistance (Cad) but not SEB. Additionally, elimination of cadmium resistance in S6 provided a plasmid-negative derivative that produced SEB at the same level as the parent. Examination of strain 277 showed two plasmids, a 37S species encoding for penicillin resistance (Penr) and a 21S species containing the gene(s) responsible for tetracycline resistance (Tetr). Elimination of the 37S, penr plasmid in 277 had no effect on SEB production, whereas introduction of the 21S tetr plasmid via transformation into strain 8325 (SEB--) did not confer enterotoxigenesis upon the transformants. The data obtained in this investigation suggest that the SEB gene(s) in these food-poisoning isolates of S. aureus is chromosomal. Images PMID:669796

  9. Locus of Control and Interpersonal Attraction.

    ERIC Educational Resources Information Center

    Fagan, M. Michael

    1980-01-01

    The role of locus of control in interpersonal attraction was examined by administering 1) the Nowicki-Strickland Locus of Control Scale and 2) a sociometric test of friendship to 200 eighth graders. (CM)

  10. Linkage disequilibrium at the APA insecticidal seed protein locus of common bean (Phaseolus vulgaris L.)

    PubMed Central

    2010-01-01

    Background An interesting seed protein family with a role in preventing insect herbivory is the multi-gene, APA family encoding the α-amylase inhibitor, phytohemagglutinin and arcelin proteins of common bean (Phaseolus vulgaris). Variability for this gene family exists and has been exploited to breed for insect resistance. For example, the arcelin locus has been successfully transferred from wild to cultivated common bean genotypes to provide resistance against the bruchid species Zabrotes subfasciatus although the process has been hampered by a lack of genetic tools for and understanding about the locus. In this study, we analyzed linkage disequilibrium (LD) between microsatellite markers at the APA locus and bruchid resistance in a germplasm survey of 105 resistant and susceptible genotypes and compared this with LD in other parts of the genome. Results Microsatellite allele diversity was found to vary with each of the eight APA-linked markers analyzed, and two markers within the APA locus were found to be diagnostic for bruchid resistance or susceptibility and for the different arcelin alleles inherited from the wild accessions. Arc1 was found to provide higher levels of resistance than Arc5 and the markers in the APA locus were highly associated with resistance showing that introgression of this gene-family from wild beans provides resistance in cultivated beans. LD around the APA locus was found to be intermediate compared to other regions of the genome and the highest LD was found within the APA locus itself for example between the markers PV-atct001 and PV-ag004. Conclusions We found the APA locus to be an important genetic determinant of bruchid resistance and also found that LD existed mostly within the APA locus but not beyond it. Moderate LD was also found for some other regions of the genome perhaps related to domestication genes. The LD pattern may reflect the introgression of arcelin from the wild into the cultivated background through breeding. LD

  11. Locus of Control and Status Attainment.

    ERIC Educational Resources Information Center

    Bensman, Miriam Roza; Haller, Archibald O.

    Utilizing data derived from 277 rural, male respondents initially enrolled in Lenawee County, Michigan high schools, the Rotter's Internal-External Locus of Control Scale was employed to test the hypothesis that locus of control will have interactive rather than additive effects on the process of status attainment. Locus of control was defined as…

  12. Novel polycarboxylated EDTA-type cyclodextrins as ligands for lanthanide binding: study of their luminescence, relaxivity properties of Gd(iii) complexes, and PM3 theoretical calculations.

    PubMed

    Maffeo, Davide; Lampropoulou, Maria; Fardis, Michael; Lazarou, Yannis G; Mavridis, Irene M; Mavridou, Despoina A I; Urso, Elena; Pratsinis, Harris; Kletsas, Dimitris; Yannakopoulou, Konstantina

    2010-04-21

    Novel -type cyclodextrin (CD) derivatives, , and , bearing 6, 7 and 8 bis(carboxymethyl)amino (iminodiacetic acid) groups, respectively, were prepared, and their complexation with Eu(iii), Tb(iii) and Gd(iii) ions was studied. Luminescence titrations and mass spectrometry showed formation of multimetal complexes ( 2 to 3, mainly 3 and exactly 4 metal ions), whereas luminescence lifetime measurements revealed the presence of exchangeable water molecules. Semiempirical quantum mechanical calculations, performed by the PM3 method and assessed by DFT calculations on model ligands, indicated efficient multi-metal complexation, in agreement with the experiment. The structures showed coordination of the metal ions in the outer primary side of the CDs via 4 carboxylate O atoms, 2 N atoms and a glucopyranose O atom per metal ion. Coordination of water molecules was also predicted, in accordance with experimental results. Calculated bond lengths and angles were in agreement with literature experimental values of lanthanide complexes. Calculated energies showed that complex stability decreases in the order > > . (1)H NMR molecular relaxivity measurements for the Gd(iii) complexes of , or in water afforded values 4 to 10 times higher than the relaxivity of a commercial contrast agent at 12 MHz, and 6 to 20 times higher at 100 MHz. Solutions of and Gd(iii) complexes in human blood plasma displayed relaxivity values at 100 MHz 7 and 12 times, respectively, higher than the commercial agent. MTT tests of the Gd(iii) complexes using human skin fibroblasts did not show toxicity. Attempts to supramolecularly sensitize the luminescence of the lanthanide complexes using various aromatic CD guests were ineffective, evidently due to large guest-metal distances and inefficient inclusion. The described lanthanide complexes, could be useful as contrast agents in MRI. PMID:20449498

  13. Detection of a quantitative trait locus for both foliage and tuber resistance to late blight [Phytophthora infestans (Mont.) de Bary] on chromosome 4 of a dihaploid potato clone (Solanum tuberosum subsp. tuberosum).

    PubMed

    Bradshaw, John E; Hackett, Christine A; Lowe, Robert; McLean, Karen; Stewart, Helen E; Tierney, Irene; Vilaro, Marco D R; Bryan, Glenn J

    2006-09-01

    Linkage analysis, Kruskal-Wallis analysis, interval mapping and graphical genotyping were performed on a potato diploid backcross family comprising 120 clones segregating for resistance to late blight. A hybrid between the Solanum tuberosum dihaploid clone PDH247 and the long-day-adapted S. phureja clone DB226(70) had been crossed to DB226(70) to produce the backcross family. Eighteen AFLP primer combinations provided 186 and 123 informative maternal and paternal markers respectively, with 63 markers in common to both parents. Eleven microsatellite (SSR) markers proved useful for identifying chromosomes. Linkage maps of both backcross parents were constructed. The results of a Kruskal-Wallis analysis, interval mapping and graphical genotyping were all consistent with a QTL or QTLs for blight resistance between two AFLP markers 30 cM apart on chromosome 4, which was identified by a microsatellite marker. The simplest explanation of the results is a single QTL with an allele from the dihaploid parent conferring resistance to race 1, 4 of P. infestans in the foliage in the glasshouse and to race 1, 2, 3, 4, 6, 7 in the foliage in the field and in tubers from glasshouse raised plants. The QTL was of large effect, and explained 78 and 51% of the variation in phenotypic scores for foliage blight in the glasshouse and field respectively, as well as 27% of the variation in tuber blight. Graphical genotyping and the differences in blight scores between the parental clones showed that all of the foliage blight resistance is accounted for by chromosome 4, whereas undetected QTLs for tuber resistance probably exist on other chromosomes. Graphical genotyping also explained the lack of precision in mapping the QTL(s) in terms of lack of appropriate recombinant chromosomes. PMID:16845519

  14. Factors Determining Adolescent Locus of Control.

    ERIC Educational Resources Information Center

    Kopera-Frye, Karen F.; And Others

    Previous research has demonstrated an association between locus of control in adolescence and a successful transition to adulthood. Having an external locus of control has been implicated as an important factor in adolescent behaviors such as teenage pregnancy and delinquency, and has been found to be negatively related to school achievement. This…

  15. Locus of Control as a Mediator of College Students' Reactions to Teacher Compliance Attempts.

    ERIC Educational Resources Information Center

    Stewart, Robert A.; And Others

    A study was conducted to determine the effects of student locus of control on perceptions of and resistance to teacher influence attempts. Subjects, 302 college students, were provided with 22 sets of Behavior Alteration Messages and were instructed to rate on a 1-5 scale "how frequently your teacher uses statements of each type to get you to…

  16. Recombination at the Rp1 locus of maize.

    PubMed

    Hulbert, S H; Bennetzen, J L

    1991-05-01

    The Rp1 locus of maize determines resistance to races of the maize rust fungus (Puccinia sorghi). Restriction fragment length polymorphism markers that closely flank Rp1 were mapped and used to study the genetic fine structure and role of recombination in the instability of this locus. Susceptible progeny, lacking the resistance of either parent, were obtained from test cross progeny of several Rp1 heterozygotes. These susceptible progeny usually had non-parental genotypes at flanking marker loci, thereby verifying their recombinational origin. Seven of eight Rp1 alleles (or genes) studied were clustered within about 0.2 map units of each other. Rp1G, however, mapped from 1-3 map units distal to other Rp1 alleles. Rp5 also mapped distally to most Rp1 alleles. Other aspects of recombination at Rp1 suggested that some alleles carry duplicated sequences, that mispairing can occur, and that unequal crossing-over may be a common phenomenon in this region; susceptible progeny from an Rp1A homozygote had recombinant flanking marker genotypes, and susceptible progeny from an Rp1D/Rp1F heterozygote showed both possible nonparental flanking marker genotypes. PMID:1674815

  17. A locus on chromosome 7 determines myocardial cell necrosis and calcification (dystrophic cardiac calcinosis) in mice.

    PubMed Central

    Ivandic, B T; Qiao, J H; Machleder, D; Liao, F; Drake, T A; Lusis, A J

    1996-01-01

    Dystrophic cardiac calcinosis, an age-related cardiomyopathy that occurs among certain inbred strains of mice, involves myocardial injury, necrosis, and calcification. Using a complete linkage map approach and quantitative trait locus analysis, we sought to identify genetic loci determining dystrophic cardiac calcinosis in an F2 intercross of resistant C57BL/6J and susceptible C3H/HeJ inbred strains. We identified a single major locus, designated Dyscalc, located on proximal chromosome 7 in a region syntenic with human chromosomes 19q13 and 11p15. The statistical significance of Dyscalc (logarithm of odds score 14.6) was tested by analysis of permuted trait data. Analysis of BxH recombinant inbred strains confirmed the mapping position. The inheritance pattern indicated that this locus influences susceptibility of cells both to enter necrosis and to subsequently undergo calcification. Images Fig. 1 Fig. 3 PMID:8643601

  18. Fine Mapping and Introgressing a Fissure Resistance Locus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice (Oryza sativa L.) kernel fissuring is a major concern of both rice producers and millers. Fissures are small cracks in rice kernels that increase breakage among kernels when transported or milled, which decrease the value of processed rice. This study employed molecular gene tagging methods to ...

  19. Evolutionary analysis of RB/Rpi-blb1 locus in the Solanaceae family.

    PubMed

    Xie, Zhengqing; Si, Weina; Gao, Rongchao; Zhang, Xiaohui; Yang, Sihai

    2015-12-01

    Late blight caused by the oomycete Phytophthora infestans is one of the most severe threats to potato production worldwide. Numerous studies suggest that the most effective protective strategy against the disease would be to provide potato cultivars with durable resistance (R) genes. However, little is known about the origin and evolutional history of these durable R-genes in potato. Addressing this might foster better understanding of the dynamics of these genes in nature and provide clues for identifying potential candidate R-genes. Here, a systematic survey was executed at RB/Rpi-blb1 locus, an exclusive broad-spectrum R-gene locus in potato. As indicated by synteny analysis, RB/Rpi-blb1 homologs were identified in all tested genomes, including potato, tomato, pepper, and Nicotiana, suggesting that the RB/Rpi-blb1 locus has an ancient origin. Two evolutionary patterns, similar to those reported on RGC2 in Lactuca, and Pi2/9 in rice, were detected at this locus. Type I RB/Rpi-blb1 homologs have frequent copy number variations and sequence exchanges, obscured orthologous relationships, considerable nucleotide divergence, and high non-synonymous to synonymous substitutions (Ka/Ks) between or within species, suggesting rapid diversification and balancing selection in response to rapid changes in the oomycete pathogen genomes. These characteristics may serve as signatures for cloning of late blight resistance genes. PMID:26008792

  20. Exercise Adherence and Locus of Control.

    ERIC Educational Resources Information Center

    Geshuri, Yosef; Glahn, Ronald

    In 1990, a study was conducted to investigate the relationship between students' locus of control and the extent to which they participated in a voluntary exercise program. First-time participants in the "Shape Up" program offered at the Porterville College Fitness Center during the summer and fall semesters of 1990 were identified through the…

  1. Locus of Control Differences and Marital Dissatisfaction.

    ERIC Educational Resources Information Center

    Doherty, William J.

    1981-01-01

    Studied the relationship between spouses' individual expectancies for internal versus external control of reinforcements (locus of control), and their level of marital dissatisfaction. Results indicated that only a marital pattern in which the wife was more external and the husband more internal was associated with marital dissatisfaction. (Author)

  2. The Measurement of Parenting Locus of Control.

    ERIC Educational Resources Information Center

    Kralj, M. M.; And Others

    The present study describes the construction of a scale for reliably measuring the extent to which parents form generalized expectancies of the degree to which their children's behaviors are contingent on their own actions as parents. The original 72 statements included in the Parenting Locus of Control (PLOC) scale ascribed cause to one of four…

  3. The Effect of Locus of Control and Locus of Reinforcement on Academic Task Persistence

    ERIC Educational Resources Information Center

    Morris, Susan; Messer, Stanley B.

    1978-01-01

    Examines the differential effectiveness of using external reinforcement versus self reinforcement to increase the task persistence of children characterized by internal or external locus of control. Subjects were 153 fourth and fifth grade boys. (BD)

  4. IlvHI locus of Salmonella typhimurium.

    PubMed

    Squires, C H; De Felice, M; Lago, C T; Calvo, J M

    1983-06-01

    In Escherichia coli K-12, the ilvHI locus codes for one of two acetohydroxy acid synthase isoenzymes. A region of the Salmonella typhimurium genome adjacent to the leucine operon was cloned on plasmid pBR322, yielding plasmids pCV47 and pCV49 (a shortened version of pCV47). This region contains DNA homologous to the E. coli ilvHI locus, as judged by hybridization experiments. Plasmid pCV47 did not confer isoleucine-valine prototrophy upon either E. coli or S. typhimurium strains lacking acetohydroxy acid synthase activity, suggesting that S. typhimurium lacks a functional ilvHI locus. However, isoleucine-valine prototrophs were readily isolated from such strains after mutagenesis with nitrosoguanidine. In one case we found that the Ilv+ phenotype resulted from an alteration in bacterial DNA on the plasmid (new plasmid designated pCV50). Furthermore, a new acetohydroxy acid synthase activity was observed in Ilv+ revertants; this enzyme was similar to E. coli acetohydroxy acid synthase III in its lack of activity at low pH. This new activity was correlated with the appearance in minicells of a new polypeptide having an approximate molecular weight of 61,000. Strains carrying either pCV49 or pCV50 produced a substantial amount of ilvHI-specific mRNA. These results, together with results from other laboratories, suggest that S. typhimurium has functional ilvB and ilvG genes and a cryptic ilvHI locus. E. coli K-12, on the other hand, has functional ilvB and ilvHI genes and a cryptic ilvG locus. PMID:6189818

  5. Locus of Control: The Effect on Reading and Instructional Preference.

    ERIC Educational Resources Information Center

    Fisher, Richard I; Dyer, Barbara

    1978-01-01

    One hundred seventy-five college students were tested to determine the relationship among locus of control, student preference, and teaching procedures. Results showed that external locus of control students preferred hardware as instructional devices and that such devices improved their reading rates, while internal locus of control students…

  6. Self-Esteem, Locus of Control, and Student Achievement.

    ERIC Educational Resources Information Center

    Sterbin, Allan; Rakow, Ernest

    The direct effects of locus of control and self-esteem on standardized test scores were studied. The relationships among the standardized test scores and measures of locus of control and self-esteem for 12,260 students from the National Education Longitudinal Study 1994 database were examined, using the same definition of locus of control and…

  7. Locus of Control and Psychological Distress among the Aged.

    ERIC Educational Resources Information Center

    Hale, W. Daniel; And Others

    1986-01-01

    Examined relationship between locus of control and self-reported psychopathology in 139 residents of retirement complex. Correlation coefficients computed for locus of control and each of nine symptom dimensions of the Brief Symptom Inventory indicated that locus of control was correlated with self-reported psychopatholgoy for older women but not…

  8. The Impact of Locus of Control on Language Achievement

    ERIC Educational Resources Information Center

    Nodoushan, Mohammad Ali Salmani

    2012-01-01

    This study hypothesized that students' loci of control affected their language achievement. 198 (N = 198) EFL students took the Rotter's (1966) locus of control test and were classified as locus-internal (ni = 78), and locus-external (ne = 120). They then took their ordinary courses and at the end of the semester, they were given their exams.…

  9. Toward an Abbreviated Internal-External Locus of Control Scale.

    ERIC Educational Resources Information Center

    Harris, Robert M., Jr.; Salomone, Paul R.

    1981-01-01

    Integrates a review of Rotter's theory with an analysis of the design and development of locus of control scales, and tests the reliability and validity of an abbreviated version of Rotter's Locus of Control Scale which provides practitioners with an instrument less confusing than other locus of control scales. (Author)

  10. The Lsktm1 Locus Modulates Lung and Skin Tumorigenesis in the Mouse

    PubMed Central

    Galvan, Antonella; Colombo, Francesca; Noci, Sara; Pazzaglia, Simonetta; Mancuso, Mariateresa; Manenti, Giacomo; Broman, Karl W.; Saran, Anna; Dragani, Tommaso A.

    2012-01-01

    Alleles derived from skin tumor−resistant Car-R mice provide resistance to both skin and lung tumorigenesis over the susceptibility of the SWR/J strain. In an effort to map tumor modifier loci affecting both tumor types, we carried out a genetic linkage analysis in backcross SWR/J x (SWR/J x Car-R) mice and identified a locus (Lsktm1) on chromosome 1 linked to both skin (LOD score = 3.93) and lung (LOD score = 8.74) tumorigenesis. Two genes, Igfbp5 and Igfbp2, residing in this locus and belonging to the insulin-like growth factor binding protein family were expressed at significantly greater levels in normal lung tissue from cancer-resistant Car-R mice than in cancer-susceptible SWR/J mice. Overexpression of the recombinant Igfbp5 and Igfbp2 genes in two lung cancer cell lines significantly inhibited clonogenicity (P < 0.0001). Collectively, we have identified a single polymorphic locus that affects skin and lung tumorigenesis and identify Igfbp5 and Igfbp2 as candidate modifier genes of lung tumorigenesis. PMID:22973541

  11. Bipolar disorder: Evidence for a major locus

    SciTech Connect

    Spence, M.A.; Flodman, P.L.; Sadovnick, A.D.; Ameli, H.

    1995-10-09

    Complex segregation analyses were conducted on families of bipolar I and bipolar II probands to delineate the mode of inheritance. The probands were ascertained from consecutive referrals to the Mood Disorder Service, University Hospital, University of British Columbia and diagnosed by DSM-III-R and Research Diagnostic Criteria. Data were available on over 1,500 first-degree relatives of the 186 Caucasian probands. The purpose of the analyses was to determine if, after correcting for age and birth cohort, there was evidence for a single major locus. Five models were fit to the data using the statistical package SAGE: (1) dominant, (2) recessive, (3) arbitrary mendelian inheritance, (4) environmental, and (5) no major effects. A single dominant, mendelian major locus was the best fitting of these models for the sample of bipolar I and II probands when only bipolar relatives were defined as affected (polygenic inheritance could not be tested). Adding recurrent major depression to the diagnosis {open_quotes}affected{close_quotes} for relatives reduced the evidence for a major locus effect. Our findings support the undertaking of linkage studies and are consistent with the analyses of the National Institutes of Mental Health (NIMH) Collaborative Study data by Rice et al. and Blangero and Elston. 39 refs., 4 tabs.

  12. TNXB locus may be a candidate gene predisposing to schizophrenia.

    PubMed

    Wei, J; Hemmings, G P

    2004-02-15

    We report here on the detection of nine single nucleotide polymorphisms (SNPs) near to the NOTCH4 locus in the search for schizophrenia susceptibility genes in the class III region of the human major histocompatibility complex (MHC). We totally analyzed 122 family trios recruited in the UK. The TDT analysis demonstrated that of the nine SNPs, three were associated with schizophrenia, including rs1009382 (P = 0.00047), rs204887 (P = 0.007), and rs8283 (P = 0.015). Both rs1009382 and rs204887 are present in the TNXB locus. The rs1009382 is a non-synonymous SNP located in exon 23 of the gene and its A to G base change causes a Glu2578Gly substitution. The goodness-of-fit test showed that genotypic distribution of rs1009382 was deviated from Hardy-Weinberg equilibrium due to homozygote excess in the patient group (P = 0.01), suggesting that a double dose of a genetic risk may be involved. Possibly, rs1009382 is a candidate SNP predisposing to a schizophrenic illness. Moreover, the test for linkage disequilibrium (LD) between paired SNPs showed that the nine SNPs studied may be in the same LD block with an unexpected pattern as the strength of LD was not correlated with the distance between paired SNPs. The haplotype analysis suggested that there might be more than one disease-related allele located in the class III region of the MHC, and that these alleles possibly confer either susceptibility or resistance to schizophrenia. PMID:14755442

  13. Locus Adh of Drosophila melanogaster under selection for delayed senescence

    SciTech Connect

    Khaustova, N.D.

    1995-05-01

    Dynamics of the Adh activity and frequencies of alleles Adh{sup F} and Adh{sup S} were analyzed under selection for delayed senescence. The experiments were performed on Drosophila melanogaster. Lines Adh{sup S}cn and Adh{sup F}vg and experimental populations cn` and vg`, selected for an increased duration of reproductive period (late oviposition) were used. Analysis of fertility, longevity, viability and resistance to starvation showed that selection for late oviposition resulted in delayed senescence of flies of the experimental populations. Genetic structure of population vg` changed considerably with regard to the Adh locus. This was confirmed by parameters of activity, thermostability, and electrophoretic mobility of the enzyme isolated from flies after 30 generations of selection. Analysis of frequencies of the Adh alleles showed that in both selected populations, which initially had different genetic composition, accumulated allele Adh{sup S}, which encodes the isozyme that is less active but more resistant to inactivation. Genetic mechanism of delayed senescence in Drosophila is assumed to involve selection at vitally important enzyme loci, including Adh. 18 refs., 2 tabs., 4 figs.

  14. Molecular structures and conformations of 1-benzenesulphonyl-2-oxo-5-alkoxypyrrolidines with anti-amnesic activity. X-ray, 1H-NMR and quantum mechanical (PM3) studies

    NASA Astrophysics Data System (ADS)

    Amato, Maria E.; Bandoli, Giuliano; Dolmella, Alessandro; Grassi, Antonio; Pappalardo, Giuseppe C.; Toja, Emilio

    1991-04-01

    The crystal and molecular structures of the nootropic agents RU-47001 ((±) 1-(4-nitrobenzenesulphonyl)-2-oxo-5-ethoxypyrrolidine) and RU-47064 ((±) 1-(4-nitrobenzenesulphonyl)-2-oxo-5-isopropyloxypyrrolidine) have been determined by X-ray analysis and their solution conformation has been investigated using 1H NMR spectroscopy. The conformations of these molecules together with those of their analogues RU-35929 ((±) 1-benzenesulphonyl-2-oxo-5-ethoxypyrrolidine), RU-47010 ((±) 1-(3-pyridinylsulphonyl)-2-oxo-5-ethoxypyrrolidine) and RU-35965 ((±) 1-benzenesulphonyl-2-oxo-5-isopropyloxypyrrolidine) have been deduced from semi-quantitative PM3 type theoretical calculations. The main feature of all compounds consists of a common envelope conformation with C (4) at the flap of the pyrrolidinone ring in the solid, that in solution changes into the analogous, but opposite, possible puckered conformational isomer. The 5-alkoxy groups were found rather flexible in solution. Theoretical preferred conformations about NS and SC bonds were in acceptable agreement with those of the solid state. The calculated torsional energetics suggested that 1- 5 do not undergo conformational interconversion.

  15. Phase controlled colour tuning of samarium and europium complexes and excellent photostability of their PVA encapsulated materials. Structural elucidation, photophysical parameters and the energy transfer mechanism in the Eu(3+) complex by Sparkle/PM3 calculations.

    PubMed

    Dar, Wakeel Ahmed; Iftikhar, K

    2016-06-01

    Luminescent [Sm(acac)3(pyz)2] (1) and [Eu(acac)3(pyz)2] (2) complexes (acac is the anion of acetylacetone and pyz is pyrazine) have been synthesized and thoroughly characterized by microanalyses, TGA, DTA, IR, ESI-MS(+) and NMR spectroscopy. The photophysical properties of these complexes have been investigated. The Sparkle/PM3 model was utilized for predicting the ground-state geometry of (2). The Judd-Ofelt intensity parameters, radiative parameters, intramolecular energy transfer rates and quantum efficiency are calculated and discussed. The intramolecular energy transfer rates predict that the major energy transfer (96%) is from the ligand triplet state to the levels (5)D1 (74.53%) and (5)D0 (21.87%) of the Eu(3+) ion, in the complex. Complexes (1) and (2) were analysed for colour tuning properties and these show varying colours upon changing phases. This property would possibly allow the use of these complexes as 'colour indicators'. The photoluminescence and photostability of the thin hybrid films of both complexes (1) and (2) in polyvinyl alcohol (PVA) are investigated and discussed. The hybrid films of (1) and (2) are quite robust due to their higher photostability. An important feature of complex (2) is that the excitation window extends close to the visible range (393 nm). The lasing property of the Eu(3+) complex in various phases is also presented. PMID:27157414

  16. β-Lactam antibiotics. Spectroscopy and molecular orbital (MO) calculations . Part I: IR studies of complexation in penicillin-transition metal ion systems and semi-empirical PM3 calculations on simple model compounds

    NASA Astrophysics Data System (ADS)

    Kupka, Teobald

    1997-12-01

    IR studies were preformed to determine possible transition metal ion binding sites of penicillin. the observed changes in spectral position and shape of characteristic IR bands of cloxacillin in the presence of transition metal ions (both in solutions and in the solid state) indicate formation of M-L complexes with engagement of -COO - and/or -CONH- functional groups. The small shift of νCO towards higher frequencies rules out direct M-L interaction via β-lactam carbonyl. PM3 calculations on simple model compounds (substituted formamide, cyclic ketones, lactams and substituted monocyclic β-lactams) have been performed. All structures were fully optimized and the calculated bond lengths, angles, heats of formation and CO stretching frequencies were discussed to determine the β-lactam binding sites and to explain its susceptibility towards nucleophilic attack (hydrolysis in vitro) and biological activity. The relative changes of calculated values were critically compared with available experimental data and same correlation between structural parameters and in vivo activity was shown.

  17. Multiple Disease Resistance in Plants.

    PubMed

    Wiesner-Hanks, Tyr; Nelson, Rebecca

    2016-08-01

    Many plants, both in nature and in agriculture, are resistant to multiple diseases. Although much of the plant innate immunity system provides highly specific resistance, there is emerging evidence to support the hypothesis that some components of plant defense are relatively nonspecific, providing multiple disease resistance (MDR). Understanding MDR is of fundamental and practical interest to plant biologists, pathologists, and breeders. This review takes stock of the available evidence related to the MDR hypothesis. Questions about MDR are considered primarily through the lens of forward genetics, starting at the organismal level and proceeding to the locus level and, finally, to the gene level. At the organismal level, MDR may be controlled by clusters of R genes that evolve under diversifying selection, by dispersed, pathogen-specific genes, and/or by individual genes providing MDR. Based on the few MDR loci that are well-understood, MDR is conditioned by diverse mechanisms at the locus and gene levels. PMID:27296142

  18. Finemapping of the arthritis QTL Pia7 reveals co-localization with Oia2 and the APLEC locus.

    PubMed

    Rintisch, C; Kelkka, T; Norin, U; Lorentzen, J C; Olofsson, P; Holmdahl, R

    2010-04-01

    In this study, we sought to determine the effect of the quantitative trait locus Pia7 on arthritis severity. The regulatory locus derived from the arthritis-resistant E3 rat strain was introgressed into the arthritis-susceptibility DA strain through continuous backcrossing. Congenic rats were studied for their susceptibility to experimental arthritis using pristane and adjuvant oil. In addition, cell number and function of various leukocyte populations were analyzed either under naive or stimulated conditions. We found that the minimal congenic fragment of DA.E3-Pia7 rats overlapped with the minimal fragment in DA.PVG-Oia2 congenic rats, which has been positionally cloned to the antigen-presenting lectin-like receptor complex (APLEC) genes. DA.E3-Pia7 congenic rats were protected from both PIA and OIA, but the protection was more pronounced in OIA. In adoptive transfer experiments we observed that the Pia7 locus controlled the priming of arthritogenic T cells and not the effector phase. In addition, Pia7 congenic rats had a significant higher frequency of B cells and granulocytes as well as TNFalpha production after stimulation, indicating a higher activation state of cells of the innate immune system. In conclusion, this study shows that the APLEC locus is a major locus regulating the severity of experimentally induced arthritis in rats. PMID:20200546

  19. Root Locus Algorithms for Programmable Pocket Calculators

    NASA Technical Reports Server (NTRS)

    Wechsler, E. R.

    1983-01-01

    Two algorithms are described which allow the plotting of individual points on a root locus diagram with or without time delay. The development was performed during the design of a continuous phase shifter used in the Baseband Antenna Combiner for the Deep Space Network (DSN). The algorithms, which are expected to be useful in similar DSN efforts, are simple enough to be implemented on a programmable pocket calculator. The coordinates of the open-loop zeros and poles, the gain constant K, and the time delay T are the data inputs.

  20. Direct and indirect relationship between locus of control and depression.

    PubMed

    Yu, Xiaobo; Fan, Guanhua

    2016-07-01

    This study examined the mediating effect of self-esteem on the relationship between locus of control and depression among Chinese university students. In all, 457 students (232 men and 225 women) completed measures of locus of control, self-esteem, and depression. Correlational analyses indicated that external locus of control was related to self-esteem and depression, and self-esteem was related to depression. Structural equation modeling analysis showed that self-esteem partially mediated the influence of locus of control on depression. The significance of the results is discussed. PMID:25305190

  1. Clutter locus equation for more general linear array orientation

    NASA Astrophysics Data System (ADS)

    Bickel, Douglas L.

    2011-06-01

    The clutter locus is an important concept in space-time adaptive processing (STAP) for ground moving target indicator (GMTI) radar systems. The clutter locus defines the expected ground clutter location in the angle-Doppler domain. Typically in literature, the clutter locus is presented as a line, or even a set of ellipsoids, under certain assumptions about the geometry of the array. Most often, the array is assumed to be in the horizontal plane containing the velocity vector. This paper will give a more general 3-dimensional interpretation of the clutter locus for a general linear array orientation.

  2. Molecular cloning of the c locus of Zea mays: a locus regulating the anthocyanin pathway.

    PubMed

    Paz-Ares, J; Wienand, U; Peterson, P A; Saedler, H

    1986-05-01

    The c locus of Zea mays, involved in the regulation of anthocyanin biosynthesis, has been cloned by transposon tagging. A clone (# 18En) containing a full size En1 element was initially isolated from the En element-induced mutable allele c-m668655. Sequences of clone # 18En flanking the En1 element were used to clone other c mutants, whose structure was predicted genetically. Clone #23En (isolated from c-m668613) contained a full size En1 element, clone #3Ds (isolated from c-m2) a Ds element and clone # 5 (isolated from c+) had no element on the cloned fragment. From these data we conclude that the clones obtained contain at least part of the c locus. Preliminary data on transcript analysis using a 1-kb DNA fragment from wild-type clone # 5 showed that at least three transcripts are encoded by that part of the locus, indicating that c is a complex locus. PMID:15957214

  3. Excited-state studies of polyacenes: A comparative picture using EOMCCSD, CR-EOMCCSD(T), range-separated (LR/RT)-TDDFT, TD-PM3 and TD-ZINDO

    SciTech Connect

    Lopata, Kenneth A.; Reslan, Randa; Kowalska, Malgorzata I.; Neuhauser, Daniel; Govind, Niranjan; Kowalski, Karol

    2011-11-08

    The low-lying excited states (L{sub a} and L{sub b}) of polyacenes from naphthalene to heptacene (N = 2-7) are studied using various time-dependent computational approaches. We perform high-level excited-state calculations using equation of motion coupled cluster with singles and doubles (EOMCCSD) and completely renormalized equation of motion coupled cluster with singles, doubles, and perturbative triples (CR-EOMCCSD(T)) and use these results to evaluate the performance of various range-separated exchange-correlation functionals within linearresponse (LR) and real-time (RT) time-dependent density functional theories (TDDFT). As has been reported recently, we find that the range-separated family of functionals address the well-documented TDDFT failures in describing these low-lying singlet excited states to a large extent and are as about as accurate as results from EOMCCSD on average. Real-time TDDFT visualization shows that the excited state charged densities are consistent with the predictions of the perimeter free electron orbital (PFEO) model. This corresponds to particle-on-a-ring confinement, which leads to the well-known red-shift of the excitations with acene length. We also use time-dependent semi-empirical methods like TD-PM3 and TD-ZINDO, which are capable of handling very large systems. Once re-parametrized to match the CR-EOMCCSD(T) results, TD-ZINDO becomes roughly as accurate as range-separated TDDFT, which opens the door to modeling systems such as large molecular assemblies.

  4. Regulatory Mutants at the his1 Locus of Yeast

    PubMed Central

    Lax, Carol; Fogel, Seymour; Cramer, Carole

    1979-01-01

    The his1 gene in Saccharomyces cerevisiae codes for phosphoribosyl transferase, an allosteric enzyme that catalyzes the initial step in histidine biosynthesis. Mutants that specifically alter the feedback regulatory function were isolated by selecting his1 prototrophic revertants that overproduce and excrete histidine. The prototrophs were obtained from diploids homoallelic for his1–7 and heterozygous for the flanking markers thr3 and arg6. Among six independently derived mutant isolates, three distinct levels of histidine excretion were detected. The mutants were shown to be second-site alterations mapping at the his1 locus by recovery of the original auoxtrophic parental alleles. The double mutants, HIS1–7e, are dominant with respect to catalytic function but recessive in regulatory function. When removed from this his1–7 background, the mutant regulatory site (HIS1–e) still confers prototrophy but not histidine excretion. To yield the excretion phenotype, the primary and altered secondary sites are required in cis array. Differences in histidine excretion levels correlate with resistance to the histidine analogue, triazoalanine. PMID:385447

  5. Reversion at the HIS1 Locus of Yeast

    PubMed Central

    Fogel, Seymour; Lax, Carol; Hurst, Donald D.

    1978-01-01

    The his1 gene (chromosome V) of Saccharomyces cerevisiae specifies phosphoribosyl transferase (E.C.2.4.2.17), the first enzyme of histidine biosynthesis. This hexameric enzyme has both catalytic and regulatory functions.—The spontaneous reversion rates of seven his1 mutations were studied. The reversion rates of the alleles at the proximal end of the locus (relative to the centromere) were about 50-fold higher than distal alleles.—Spontaneous reversion to prototrophy was studied in diploids homoallelic for each of the seven his1 mutations. Based on tetrad analysis, the prototrophy revertants could be assigned to three classes: (1) revertant tetrads that carried a prototrophic allele indistinguishable from wild type; (2) revertant tetrads that carried a prototrophic allele characterized by histidine excretion and feedback resistance; and (3) revertant tetrads that did not contain a prototrophic spore, but rather a newly derived allele that complemented the original allele intragenically. Four of the seven his1 mutations produced the excretor revertant class, and two mutations produced the complementer revertant class. The significance of these findings to our understanding of gene organization and the catalytic and regulatory functions of gene products are discussed. PMID:365679

  6. Changing Locus of Control: Steelworkers Adjusting to Forced Unemployment

    ERIC Educational Resources Information Center

    Legerski, Elizabeth Miklya; Cornwall, Marie; O'Neil, Brock

    2006-01-01

    Using an abbreviated version of Levenson's (1981) locus of control scale, we examine change over time in the locus of control of displaced steelworkers. The first data collection occurred approximately six months after plant shutdown, the second occurred a year later. Utilizing a multidimensional measurement model, we test the major assumption…

  7. Itpr3 Is responsible for the mouse tufted (tf) locus.

    PubMed

    Ellis, Hillary T; Tordoff, Michael G; Parker, M Rockwell

    2013-03-01

    The tf (tufted) locus is responsible for a classic phenotype of hair loss and regrowth in mice. It is a characteristic of the BTBR strain. Here, we use a combination of positional cloning methods and complementation mapping to identify Itpr3, the inositol triphosphate receptor type 3, as the gene responsible for the tf locus. PMID:23100490

  8. Locus of Control, and Expectational Set, on Two Aptitude Measures.

    ERIC Educational Resources Information Center

    Wildstein, Arlene B.; And Others

    The purpose of this study was to investigate whether there are differences between males and females on locus of control, if experimental instructions differentially affect the performance of internals as opposed to externals, and if locus of control differentially influences performance on distinct types of aptitude tests. The Children's…

  9. Anxiety, locus of control and appraisal of air pollution

    SciTech Connect

    Navarro, P.L.; Simpson-Housley, P.; de Man, A.F.

    1987-06-01

    100 residents of Santiago de Chile took part in a study of the relationship among locus of control, trait-anxiety, and perception of air pollution. Concern over the problem of atmospheric pollution and number of antipollution measures taken was related to trait-anxiety. Locus of control was associated with variation in awareness of pollution hazard.

  10. Physical structure of an endopolygalacturonase locus in peach

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The melting flesh trait and the freestone trait are genetically linked to the same single locus in peach. Several studies have associated an endopolygalacturonase gene with this locus, either a deletion of endopolygalacturonase associated with the non-melting/clingstone phenotype or changes in the ...

  11. Personality and Locus of Control among School Children

    ERIC Educational Resources Information Center

    Pandya, Archana A.; Jogsan, Yogesh A.

    2013-01-01

    The main purpose of this investigation is to find out the sex differences in personality traits and locus of control among school children. A total 60 children (30 boys and 30 girls) were taken as a sample. The research tool for personality, children personality questionnaire was used, which was made by Cattell and Porter. Locus of control was…

  12. Locus of Control and the Effectiveness of Social Reinforcers

    ERIC Educational Resources Information Center

    Pawlicki, Robert E.

    1974-01-01

    This study tested the hypothesis that the developmental change in the effectiveness of social reinforcement was related to changes in locus of control. A total of 145 subjects in grades 3, 4, 6, and 7 responded to the Children's Locus of Control Scale and to a simple game of measuring the effectiveness of either praise connoting or information…

  13. The Shc locus regulates insulin signaling and adiposity in mammals

    PubMed Central

    Tomilov, Alexey A.; Ramsey, Jon J.; Hagopian, Kevork; Giorgio, Marco; Kim, Kyoungmi M.; Lam, Adam; Migliaccio, Enrica; Lloyd, Kent C.; Berniakovich, Ina; Prolla, Tomas A.; Pelicci, PierGiuseppe; Cortopassi, Gino A.

    2014-01-01

    Summary Longevity of a p66Shc knockout strain (ShcP) was previously attributed to increased stress resistance and altered mitochondria. Microarrays of ShcP tissues indicated alterations in insulin signaling. Consistent with this observation, ShcP mice were more insulin sensitive and glucose tolerant at organismal and tissue levels, as was a novel p66Shc knockout (ShcL). Increasing and decreasing Shc expression in cell lines decreased and increased insulin sensitivity, respectively – consistent with p66Shc's function as a repressor of insulin signaling. However, differences between the two p66Shc knockout strains were also observed. ShcL mice were fatter and susceptible to fatty diets, and their fat was more insulin sensitive than controls. On the other hand, ShcP mice were leaner and resisted fatty diets, and their adipose was less insulin sensitive than controls. ShcL and ShcP strains are both highly inbred on the C57Bl/6 background, so we investigated gene expression at the Shc locus, which encodes three isoforms, p66, p52, and p46. Isoform p66 is absent in both strains; thus, the remaining difference to which to attribute the ‘lean’ phenotype is expression of the other two isoforms. ShcL mice have a precise deletion of p66Shc and normal expression of p52 and p46Shc isoforms in all tissues; thus, a simple deletion of p66Shc results in a ‘fat’ phenotype. However, ShcP mice in addition to p66Shc deletion have a fourfold increase in p46Shc expression in white fat. Thus, p46Shc overexpression in fat, rather than p66Shc deletion, is the likely cause of decreased adiposity and reduced insulin sensitivity in the fat of ShcP mice, which has implications for the longevity of the strain. PMID:21040401

  14. A gene locus for targeted ectopic gene integration in Zymoseptoria tritici.

    PubMed

    Kilaru, S; Schuster, M; Latz, M; Das Gupta, S; Steinberg, N; Fones, H; Gurr, S J; Talbot, N J; Steinberg, G

    2015-06-01

    Understanding the cellular organization and biology of fungal pathogens requires accurate methods for genomic integration of mutant alleles or fluorescent fusion-protein constructs. In Zymoseptoria tritici, this can be achieved by integrating of plasmid DNA randomly into the genome of this wheat pathogen. However, untargeted ectopic integration carries the risk of unwanted side effects, such as altered gene expression, due to targeting regulatory elements, or gene disruption following integration into protein-coding regions of the genome. Here, we establish the succinate dehydrogenase (sdi1) locus as a single "soft-landing" site for targeted ectopic integration of genetic constructs by using a carboxin-resistant sdi1(R) allele, carrying the point-mutation H267L. We use various green and red fluorescent fusion constructs and show that 97% of all transformants integrate correctly into the sdi1 locus as single copies. We also demonstrate that such integration does not affect the pathogenicity of Z. tritici, and thus the sdi1 locus is a useful tool for virulence analysis in genetically modified Z. tritici strains. Furthermore, we have developed a vector which facilitates yeast recombination cloning and thus allows assembly of multiple overlapping DNA fragments in a single cloning step for high throughput vector and strain generation. PMID:26092798

  15. Genomic analysis reveals candidate genes for PPV resistance in apricot (Prunus armeniaca L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sharka disease, caused by Plum pox virus (PPV), is the most important disease affecting Prunus species. A major PPV resistance locus (PPVres) was previously mapped to the upper part of apricot (Prunus armeniaca) linkage group 1. In this study, a physical map of the PPVres locus in the PPV resistan...

  16. Genome Wide Analysis of Inbred Mouse Lines Identifies a Locus Containing Ppar-γ as Contributing to Enhanced Malaria Survival

    PubMed Central

    Henson, Kerstin; Luzader, Angelina; Lindstrom, Merle; Spooner, Muriel; Steffy, Brian M.; Suzuki, Oscar; Janse, Chris; Waters, Andrew P.; Zhou, Yingyao; Wiltshire, Tim; Winzeler, Elizabeth A.

    2010-01-01

    The genetic background of a patient determines in part if a person develops a mild form of malaria and recovers, or develops a severe form and dies. We have used a mouse model to detect genes involved in the resistance or susceptibility to Plasmodium berghei malaria infection. To this end we first characterized 32 different mouse strains infected with P. berghei and identified survival as the best trait to discriminate between the strains. We found a locus on chromosome 6 by linking the survival phenotypes of the mouse strains to their genetic variations using genome wide analyses such as haplotype associated mapping and the efficient mixed-model for association. This new locus involved in malaria resistance contains only two genes and confirms the importance of Ppar-γ in malaria infection. PMID:20531941

  17. Major histocompatibility complex locus DRA polymorphism in the endangered Sorraia horse and related breeds.

    PubMed

    Luís, C; Cothran, E G; Oom, M M; Bailey, E

    2005-02-01

    The major histocompatibility complex (MHC) genes play well-defined roles in eliciting immune responses and combating infectious diseases. This genetic system is among the most polymorphic. The extent of genetic variation within a population has been directly correlated with fitness for many traits. The MHC class II locus DRA polymorphism was analysed in the endangered Sorraia horse, two other Portuguese and four New World horse breeds considered to be historically close to the Sorraia. Comparison of the Sorraia with other breeds demonstrated less MHC variation among Sorraia horses. If DRA polymorphism provides greater disease resistance, selective breeding to increase MHC polymorphism may increase fitness of this population. PMID:16130491

  18. Identifying a novel locus for psoriatic arthritis.

    PubMed

    Budu-Aggrey, Ashley; Bowes, John; Barton, Anne

    2016-01-01

    A number of studies have identified genetic risk loci for PsA, the majority of which also confer risk for psoriasis. The stronger heritability of PsA in comparison with psoriasis suggests that there should be risk loci that are specific for PsA. Identifying such loci could potentially inform therapy development to provide more effective treatments for PsA patients, especially with a considerable proportion being non-responsive to current therapies. Evidence of a PsA-specific locus has been previously found at HLA-B27 within the MHC region. A recent study has provided evidence of non-HLA risk loci that are specific for PsA at IL23R, PTPN22 and on chromosome 5q31. Functional characterization of these loci will provide further understanding of the pathways underlying PsA, and enable us to apply genetic findings for patient benefit. PMID:26255310

  19. Dental outpatients: health locus of control correlates.

    PubMed

    Ludenia, K; Donham, G W

    1983-11-01

    Examined relationships between the Multidimensional Health Locus of Control (MHLC) Scales, Beck Depression Inventory, Trait subscales of the State-Trait Personality Inventory, and dental ratings of oral hygiene and presence of periodontal disease with dental outpatients (N = 101) at a Veterans Administration Medical Center Dental Clinic. Results indicated that this sample of outpatients scored comparably on MHLC Health Internality and Health Externality to a sample reported by Wallston and Wallston. Older dental patients, in the present sample, scored significantly higher on Powerful Others Externality in contrast to younger Ss, which suggests greater reliance on health professionals for dental health. Confirmatory evidence is presented on the negative correlations of depression, anger, and anxiety with Health Internality. Differential approaches to dental treatment are discussed. PMID:6662936

  20. The Cajal Body and Histone Locus Body

    PubMed Central

    Nizami, Zehra; Deryusheva, Svetlana; Gall, Joseph G.

    2010-01-01

    The Cajal body (CB) is a nuclear organelle present in all eukaryotes that have been carefully studied. It is identified by the signature protein coilin and by CB-specific RNAs (scaRNAs). CBs contain high concentrations of splicing small nuclear ribonucleoproteins (snRNPs) and other RNA processing factors, suggesting that they are sites for assembly and/or posttranscriptional modification of the splicing machinery of the nucleus. The histone locus body (HLB) contains factors required for processing histone pre-mRNAs. As its name implies, the HLB is associated with the genes that code for histones, suggesting that it may function to concentrate processing factors at their site of action. CBs and HLBs are present throughout the interphase of the cell cycle, but disappear during mitosis. The biogenesis of CBs shows the features of a self-organizing structure. PMID:20504965

  1. Identifying a novel locus for psoriatic arthritis

    PubMed Central

    Budu-Aggrey, Ashley; Bowes, John

    2016-01-01

    A number of studies have identified genetic risk loci for PsA, the majority of which also confer risk for psoriasis. The stronger heritability of PsA in comparison with psoriasis suggests that there should be risk loci that are specific for PsA. Identifying such loci could potentially inform therapy development to provide more effective treatments for PsA patients, especially with a considerable proportion being non-responsive to current therapies. Evidence of a PsA-specific locus has been previously found at HLA-B27 within the MHC region. A recent study has provided evidence of non-HLA risk loci that are specific for PsA at IL23R, PTPN22 and on chromosome 5q31. Functional characterization of these loci will provide further understanding of the pathways underlying PsA, and enable us to apply genetic findings for patient benefit. PMID:26255310

  2. Locus of Control Orientation: Parents, Peers, and Place.

    PubMed

    Ahlin, Eileen M; Lobo Antunes, Maria João

    2015-09-01

    An internal locus of control contributes to positive youth outcomes such as a general well-being and academic success, while also serving as a protective factor against exposure to community violence and reducing negative behaviors like violence. Despite these benefits, very little is known about antecedents of an internal locus of control orientation. Without an understanding of what factors contribute to the development of an internal locus of control, it is not clear how to best encourage its formation. This study uses data from the Project on Human Development in Chicago Neighborhoods to examine whether various mesosystem variables (family management strategies, peer interactions, neighborhood context, and individual-level characteristics) are associated with an internal locus of control orientation among 1,076 youth ages 9-19 living in 78 Chicago neighborhoods. Study participants were Hispanic (46 %), African American (34 %), and White (15 %), and 50 % were female. The findings suggest that, while most levels of the mesosystem influence locus of control orientation, family management strategies are more prominent determinants of an internal locus of control than peers, neighborhood context, or individual characteristics. Parental supervision over the time a youth spends at home and family socioeconomic status are consistent predictors of an internal locus of control, while harsh discipline is associated with an external locus of control. The discussion examines the import of various parenting techniques in shaping an internal locus of control and considers future avenues for research to further unpack how antecedents of locus of control can vary across youth. PMID:25617000

  3. Validation of a major quantitative trait locus associated with host response to experimental infection with Porcine Reproductive and Respiratory Syndrome virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Infectious diseases are costly to the swine industry and porcine reproductive and respiratory syndrome virus (PRRSV) is the most devastating. In earlier work, a quantitative trait locus associated with resistance/susceptibility to PRRSV was identified on Sus scrofa chromosome 4 (SSC4) using ~560 exp...

  4. A NK complex-linked locus restricts the spread of herpes simplex virus type 1 in the brains of C57BL/6 mice.

    PubMed

    Kastrukoff, Lorne F; Lau, Allen S; Takei, Fumio; Carbone, Francis R; Scalzo, Anthony A

    2015-11-01

    The most frequent cause of sporadic viral encephalitis in western countries is Herpes simplex virus (HSV). Despite treatment, mortality rates reach 20-30% while survivors often suffer from significant morbidity. In mice, resistance to lethal Herpes simplex encephalitis (HSE) is multifactorial and influenced by mouse and virus strain as well as route of infection. The ability to restrict viral spread in the brain is one factor contributing to resistance. After infection of the oral mucosa with HSV type 1 (HSV-1), virus spreads throughout the brains of susceptible strains but is restricted in resistant C57BL/6 mice. To further investigate restriction of viral spread in the brain, mendelian analysis was combined with studies of congenic, intra-natural killer complex (intra-NKC) recombinant and antibody-depleted mice. Results from mendelian analysis support the restriction of viral spread as a dominant trait and consistent with a single gene effect. In congenic mice, the locus maps to the NKC on chromosome 6 and is provisionally termed Herpes Resistance Locus 2 (Hrl2). In intra-NKC recombinants, the locus is further mapped to the segment Cd69 through D6Wum34; a different location from previously identified loci (Hrl and Rhs1) also associated with HSV-1 infection. Studies with antibody-depleted mice indicate the effect of this locus is mediated by NK1.1(+) expressing cells. This model increases our knowledge of lethal HSE, which may lead to new treatment options. PMID:25971711

  5. Detecting purely epistatic multi-locus interactions by an omnibus permutation test on ensembles of two-locus analyses

    PubMed Central

    Wongseree, Waranyu; Assawamakin, Anunchai; Piroonratana, Theera; Sinsomros, Saravudh; Limwongse, Chanin; Chaiyaratana, Nachol

    2009-01-01

    Background Purely epistatic multi-locus interactions cannot generally be detected via single-locus analysis in case-control studies of complex diseases. Recently, many two-locus and multi-locus analysis techniques have been shown to be promising for the epistasis detection. However, exhaustive multi-locus analysis requires prohibitively large computational efforts when problems involve large-scale or genome-wide data. Furthermore, there is no explicit proof that a combination of multiple two-locus analyses can lead to the correct identification of multi-locus interactions. Results The proposed 2LOmb algorithm performs an omnibus permutation test on ensembles of two-locus analyses. The algorithm consists of four main steps: two-locus analysis, a permutation test, global p-value determination and a progressive search for the best ensemble. 2LOmb is benchmarked against an exhaustive two-locus analysis technique, a set association approach, a correlation-based feature selection (CFS) technique and a tuned ReliefF (TuRF) technique. The simulation results indicate that 2LOmb produces a low false-positive error. Moreover, 2LOmb has the best performance in terms of an ability to identify all causative single nucleotide polymorphisms (SNPs) and a low number of output SNPs in purely epistatic two-, three- and four-locus interaction problems. The interaction models constructed from the 2LOmb outputs via a multifactor dimensionality reduction (MDR) method are also included for the confirmation of epistasis detection. 2LOmb is subsequently applied to a type 2 diabetes mellitus (T2D) data set, which is obtained as a part of the UK genome-wide genetic epidemiology study by the Wellcome Trust Case Control Consortium (WTCCC). After primarily screening for SNPs that locate within or near 372 candidate genes and exhibit no marginal single-locus effects, the T2D data set is reduced to 7,065 SNPs from 370 genes. The 2LOmb search in the reduced T2D data reveals that four intronic SNPs

  6. Human Adenovirus Type 2 but Not Adenovirus Type 12 Is Mutagenic at the Hypoxanthine Phosphoribosyltransferase Locus of Cloned Rat Liver Epithelial Cells

    PubMed Central

    Paraskeva, Christos; Roberts, Carl; Biggs, Paul; Gallimore, Phillip H.

    1983-01-01

    Using resistance to the base analog 8-azaguanine as a genetic marker, we showed that adenovirus type 2, but not adenovirus type 12, is mutagenic at the hypoxanthine phosphoribosyltransferase locus of cloned diploid rat liver epithelial cells. Adenovirus type 2 increased the frequency of 8-azaguanine-resistant colonies by up to ninefold over the spontaneous frequency, depending on expression time and virus dose. PMID:6572280

  7. Low Cost Upper Atmosphere Sounder (LOCUS)

    NASA Astrophysics Data System (ADS)

    Gerber, Daniel; Swinyard, Bruce M.; Ellison, Brian N.; Aylward, Alan D.; Aruliah, Anasuya; Plane, John M. C.; Feng, Wuhu; Saunders, Christopher; Friend, Jonathan; Bird, Rachel; Linfield, Edmund H.; Davies, A. Giles; Parkes, Steve

    2014-05-01

    near future. We describe the current instrument configuration of LOCUS, and give a first preview of the expected science return such a mission would yield. The LOCUS instrument concept calls for four spectral bands, a first band at 4.7 THz to target atomic oxygen (O), a second band at 3.5 THz to target hydroxyl (OH), a third band at 1.1 THz to cover several diatomic species (NO, CO, O3, H2O) and finally a fourth band at 0.8 THz to retrieve pointing information from molecular oxygen (O2). LOCUS would be the first satellite instrument to measure atomic oxygen on a global scale with a precision that will allow the retrieval of the global O distribution. It would also be the first time that annual and diurnal changes in O are measured. This will be a significant step forward in understanding the chemistry and dynamics of the MLT. Current indications (derived from CRISTA measurement) lead us to believe that current models only give a poor representation of upper atmospheric O. The secondary target species can help us to address additional scientific questions related to both Climate (distribution of climate relevant gases, highly geared cooling of the MLT in response to Climate change, increased occurrence of Polar Mesospheric Clouds (PMC), etc) and Space Weather (precipitation of electrically charged particles and impact on NOx chemistry, fluctuations of solar Lyman-alpha flux through shown in the the distribution of photochemically active species, etc).

  8. Relation of organizational citizenship behavior and locus of control.

    PubMed

    Turnipseed, David L; Bacon, Calvin M

    2009-12-01

    The relation of organizational citizenship behavior and locus of control was assessed in a sample of 286 college students (52% men; M age = 24 yr.) who worked an average of 26 hr. per week. Measures were Spector's Work Locus of Control Scale and Podsakoff, et al.'s Organization Citizenship Behavior scale. Hierarchical multiple regressions indicated positive association of scores on work locus of control with scores on each of the four tested dimensions of organizational citizenship, as well as total organizational citizenship behavior. PMID:20099548

  9. Pseudohypoparathyroidism Type Ib Associated with Novel Duplications in the GNAS Locus

    PubMed Central

    Perez-Nanclares, Gustavo; Velayos, Teresa; Vela, Amaya; Muñoz-Torres, Manuel; Castaño, Luis

    2015-01-01

    Context Pseudohypoparathyroidism type 1b (PHP-Ib) is characterized by renal resistance to PTH (and, sometimes, a mild resistance to TSH) and absence of any features of Albright's hereditary osteodystrophy. Patients with PHP-Ib suffer of defects in the methylation pattern of the complex GNAS locus. PHP-Ib can be either sporadic or inherited in an autosomal dominant pattern. Whereas familial PHP-Ib is well characterized at the molecular level, the genetic cause of sporadic PHP-Ib cases remains elusive, although some molecular mechanisms have been associated with this subtype. Objective The aim of the study was to investigate the molecular and imprinting defects in the GNAS locus in two unrelated patients with PHP-Ib. Design We have analyzed the GNAS locus by direct sequencing, Methylation-Specific Multiplex Ligation-dependent Probe Amplification, microsatellites, Quantitative Multiplex PCR of Short Fluorescent fragments and array-Comparative Genomic Hybridization studies in order to characterize two unrelated families with clinical features of PHP-Ib. Results We identified two duplications in the GNAS region in two patients with PHP-Ib: one of them, comprising ∼320 kb, occurred ‘de novo’ in the patient, whereas the other one, of ∼179 kb in length, was inherited from the maternal allele. In both cases, no other known genetic cause was observed. Conclusion In this article, we describe the to-our-knowledge biggest duplications reported so far in the GNAS region. Both are associated to PHP-Ib, one of them occurring ‘de novo’ and the other one being maternally inherited. PMID:25710380

  10. Association of mercury resistance with antibiotic resistance in the gram-negative fecal bacteria of primates.

    PubMed Central

    Wireman, J; Liebert, C A; Smith, T; Summers, A O

    1997-01-01

    Gram-negative fecal bacterial from three longitudinal Hg exposure experiments and from two independent survey collections were examined for their carriage of the mercury resistance (mer) locus. The occurrence of antibiotic resistance was also assessed in both mercury-resistant (Hgr) and mercury-susceptible (Hgs) isolates from the same collections. The longitudinal studies involved exposure of the intestinal flora to Hg released from amalgam "silver" dental restorations in six monkeys. Hgr strains were recovered before the installation of amalgams, and frequently these became the dominant strains while amalgams were installed. Such persistent Hgr strains always carried the same mer locus throughout the experiments. In both the longitudinal and survey collections, certain mer loci were preferentially associated with one genus, whereas other mer loci were recovered from many genera. In general, strains with any mer locus were more likely to be multiresistant than were strains without mer loci; this clustering tendency was also seen for antibiotic resistance genes. However, the association of antibiotic multiresistance with mer loci was not random; regardless of source, certain mer loci occurred in highly multiresistant strains (with as many as seven antibiotic resistances), whereas other mer loci were found in strains without any antibiotic resistance. The majority of highly multiresistant Hgr strains also carried genes characteristic of an integron, a novel genetic element which enables the formation of tandem arrays of antibiotic resistance genes. Hgr strains lacking antibiotic resistance showed no evidence of integron components. PMID:9361435

  11. Genetic and Physiological Aspects of Resistance to 5-Fluoropyrimidines in Saccharomyces cerevisiae

    PubMed Central

    Jund, Richard; Lacroute, François

    1970-01-01

    Mutants resistant to 5-fluorouracil, 5-fluorocytosine, and 5-fluorouridine were selected in yeast, and the mechanisms of their resistance were investigated. The investigated mutations map in seven different loci. (i) A mutation at the locus FUI 1 gives specifically resistance to 5-fluorouridine. (ii) Two loci are involved in a specific 5-fluorocytosine resistance: a mutation at locus FCY 1 produces a loss of cytosine deaminase activity; a mutation at locus FCY 2 results in the loss of the activity of a cytosine-specific permease. (iii) A mutation at the locus FUR 4 gives a simultaneous resistance to 5-fluorouracil and to 5-fluorouridine by loss in the activity of the uracil-specific permease. (iv) We found three types of mutants in the locus FUR 1. One is dominant and weakly resistant to 5-fluorouracil, 5-fluorocytosine, and 5-fluorouridine. The two others are recessive and are unable to catalyze one of the steps involved in uracil transformation into uridine 5′-monophosphate; this block-age explains their strong resistance to 5-fluorouracil and 5-fluorocytosine. Of these two mutants, one is resistant to 5-fluorouridine and the other is not. (v) Mutations at locus FUR 2 give resistance to 5-fluorouracil, 5-fluorocytosine, and 5-fluorouridine. These mutations are dominant and lead to a loss in the feedback regulation of the aspartic transcarbamylase activity by uridine triphosphate. (vi) The mutants FUR 3 are resistant to 5-fluorocytosine and 5-fluorouridine. They are dominant and physiologically related to the mutants of the locus FUR 1 but their mechanism of resistance is not understood. PMID:5429721

  12. The Ink4a/Arf Locus Is a Barrier to Direct Neuronal Transdifferentiation

    PubMed Central

    Price, James D.; Park, Ki-Youb; Chen, Jiadong; Salinas, Ryan D.; Cho, Mathew J.; Kriegstein, Arnold R.

    2014-01-01

    Non-neurogenic cell types, such as cortical astroglia and fibroblasts, can be directly converted into neurons by the overexpression of defined transcription factors. Normally, the cellular phenotype of such differentiated cells is remarkably stable and resists direct cell transdifferentiation. Here we show that the Ink4a/Arf (also known as Cdkn2a) locus is a developmental barrier to direct neuronal transdifferentiation induced by transcription factor overexpression. With serial passage in vitro, wild-type postnatal cortical astroglia become progressively resistant to Dlx2-induced neuronal transdifferentiation. In contrast, the neurogenic competence of Ink4a/Arf-deficient astroglia is both greatly increased and does not diminish through serial cell culture passage. Electrophysiological analysis further demonstrates the neuronal identity of cells induced from Ink4a/Arf-null astroglia, and short hairpin RNA-mediated acute knockdown of p16Ink4a and p19Arf p16Ink4a and p19Arf indicates that these gene products function postnatally as a barrier to cellular transdifferentiation. Finally, we found that mouse fibroblasts deficient for Ink4a/Arf also exhibit greatly enhanced transcription factor-induced neuronal induction. These data indicate that Ink4a/Arf is a potent barrier to direct neuronal transdifferentiation and further suggest that this locus functions normally in the progressive developmental restriction of postnatal astrocytes. PMID:25209293

  13. Guidelines for establishing locus specific databases.

    PubMed

    Vihinen, Mauno; den Dunnen, Johan T; Dalgleish, Raymond; Cotton, Richard G H

    2012-02-01

    Information about genetic variation has been collected for some 20 years into registries, known as locus specific databases (LSDBs), which nowadays often contain information in addition to the actual genetic variation. Several issues have to be taken into account when considering establishing and maintaining LSDBs and these have been discussed previously in a number of articles describing guidelines and recommendations. This information is widely scattered and, for a newcomer, it would be difficult to obtain the latest information and guidance. Here, a sequence of steps essential for establishing an LSDB is discussed together with guidelines for each step. Curators need to collect information from various sources, code it in systematic way, and distribute to the research and clinical communities. In doing this, ethical issues have to be taken into account. To facilitate integration of information to, for example, analyze genotype-phenotype correlations, systematic data representation using established nomenclatures, data models, and ontologies is essential. LSDB curation and maintenance comprises a number of tasks that can be managed by following logical steps. These resources are becoming ever more important and new curators are essential to ensure that we will have expertly curated databases for all disease-related genes in the near future. PMID:22052659

  14. The lta4h Locus Modulates Susceptibility to Mycobacterial Infection in Zebrafish and Humans

    PubMed Central

    Tobin, David M.; Vary, Jay C.; Ray, John P.; Walsh, Gregory S.; Dunstan, Sarah J.; Bang, Nguyen D.; Hagge, Deanna A.; Khadge, Saraswoti; King, Mary-Claire; Hawn, Thomas R.; Moens, Cecilia B.; Ramakrishnan, Lalita

    2010-01-01

    SUMMARY Exposure to Mycobacterium tuberculosis produces varied early outcomes, ranging from resistance to infection to progressive disease. Here we report results from a forward genetic screen in zebrafish larvae that identify multiple mutant classes with distinct patterns of innate susceptibility to Mycobacterium marinum. A hypersusceptible mutant maps to the lta4h locus encoding leukotriene A4 hydrolase, which catalyzes the final step in the synthesis of leukotriene B4 (LTB4), a potent chemoattractant and proinflammatory eicosanoid. lta4h mutations confer hypersusceptibility independent of LTB4 reduction, by redirecting eicosanoid substrates to anti-inflammatory lipoxins. The resultant anti-inflammatory state permits increased mycobacterial proliferation by limiting production of tumor necrosis factor. In humans, we find that protection from both tuberculosis and multibacillary leprosy is associated with heterozygosity for LTA4H polymorphisms that have previously been correlated with differential LTB4 production. Our results suggest conserved roles for balanced eicosanoid production in vertebrate resistance to mycobacterial infection. PMID:20211140

  15. Changing Expectancies: A Counseling Model Based on Locus of Control.

    ERIC Educational Resources Information Center

    Connolly, Sean G.

    1980-01-01

    Presents counseling and communication techniques for giving external expectancies the internal direction necessary to facilitate behavior change. Locus of control expectancies provide a useful concept for assessing and influencing the behavior of unmotivated clients. (Author)

  16. Inheritance of Race-Specific Resistance to Xanthomonas campestris pv. campestris in Brassica Genomes.

    PubMed

    Vicente, J G; Taylor, J D; Sharpe, A G; Parkin, I A P; Lydiate, D J; King, G J

    2002-10-01

    ABSTRACT The inheritance of resistance to three Xanthomonas campestris pv. campestris races was studied in crosses between resistant and susceptible lines of Brassica oleracea (C genome), B. carinata (BC genome), and B. napus (AC genome). Resistance to race 3 in the B. oleracea doubled haploid line BOH 85c and in PI 436606 was controlled by a single dominant locus (Xca3). Resistance to races 1 and 3 in the B. oleracea line Badger Inbred-16 was quantitative and recessive. Strong resistance to races 1 and 4 was controlled by a single dominant locus (Xca1) in the B. carinata line PI 199947. This resistance probably originates from the B genome. Resistance to race 4 in three B. napus lines, cv. Cobra, the rapid cycling line CrGC5, and the doubled haploid line N-o-1, was controlled by a single dominant locus (Xca4). A set of doubled haploid lines, selected from a population used previously to develop a restriction fragment length polymorphism map, was used to map this locus. Xca4 was positioned on linkage group N5 of the B. napus A genome, indicating that this resistance originated from B. rapa. Xca4 is the first major locus to be mapped that controls race-specific resistance to X. campestris pv. campestris in Brassica spp. PMID:18944224

  17. Two-locus linkage analysis in multiple sclerosis (MS)

    SciTech Connect

    Tienari, P.J. Univ. of Helsinki ); Terwilliger, J.D.; Ott, J. ); Palo, J. ); Peltonen, L. )

    1994-01-15

    One of the major challenges in genetic linkage analyses is the study of complex diseases. The authors demonstrate here the use of two-locus linkage analysis in multiple sclerosis (MS), a multifactorial disease with a complex mode of inheritance. In a set of Finnish multiplex families, they have previously found evidence for linkage between MS susceptibility and two independent loci, the myelin basic protein gene (MBP) on chromosome 18 and the HLA complex on chromosome 6. This set of families provides a unique opportunity to perform linkage analysis conditional on two loci contributing to the disease. In the two-trait-locus/two-marker-locus analysis, the presence of another disease locus is parametrized and the analysis more appropriately treats information from the unaffected family member than single-disease-locus analysis. As exemplified here in MS, the two-locus analysis can be a powerful method for investigating susceptibility loci in complex traits, best suited for analysis of specific candidate genes, or for situations in which preliminary evidence for linkage already exists or is suggested. 41 refs., 6 tabs.

  18. Fixation probability in a two-locus intersexual selection model.

    PubMed

    Durand, Guillermo; Lessard, Sabin

    2016-06-01

    We study a two-locus model of intersexual selection in a finite haploid population reproducing according to a discrete-time Moran model with a trait locus expressed in males and a preference locus expressed in females. We show that the probability of ultimate fixation of a single mutant allele for a male ornament introduced at random at the trait locus given any initial frequency state at the preference locus is increased by weak intersexual selection and recombination, weak or strong. Moreover, this probability exceeds the initial frequency of the mutant allele even in the case of a costly male ornament if intersexual selection is not too weak. On the other hand, the probability of ultimate fixation of a single mutant allele for a female preference towards a male ornament introduced at random at the preference locus is increased by weak intersexual selection and weak recombination if the female preference is not costly, and is strong enough in the case of a costly male ornament. The analysis relies on an extension of the ancestral recombination-selection graph for samples of haplotypes to take into account events of intersexual selection, while the symbolic calculation of the fixation probabilities is made possible in a reasonable time by an optimizing algorithm. PMID:27059474

  19. [Health locus of control of patients in disease management programmes].

    PubMed

    Schnee, M; Grikscheit, F

    2013-06-01

    Health locus of control beliefs plays a major role in improving self-management skills of the chronically ill - a main goal in disease management programmes (DMP). This study aims at characterising participants in disease management regarding their health locus of control. Data are based on 4 cross-sectional postal surveys between spring and autumn of 2006 and 2007 within the Health Care Monitor of the Bertelsmann Foundation. Among the 6 285 respondents, 1 266 are chronically ill and not enrolled in a DMP and 327 are participating in a DMP. A high internal locus of control (HLC) occurs significantly less often in DMP patients than in normal chronically ill patients (and healthy people) controlling for age, gender and social class. With increasing age, a high internal locus of control is also significantly less likely. When comparing healthy people, the chronically ill and the DMP participants a social gradient of a high internal locus of control belief can be observed. The weaker internal and higher doctor-related external locus of control of DMP participants should be carefully observed by the physician when trying to strengthen the patients' self-management skills. Evaluators of DMP should take into account the different baselines of DMP patients and relevant control groups and incorporate these differences into the evaluation. PMID:22864845

  20. Neurolinguistic programming training, trait anxiety, and locus of control.

    PubMed

    Konefal, J; Duncan, R C; Reese, M A

    1992-06-01

    Training in the neurolinguistic programming techniques of shifting perceptual position, visual-kinesthetic dissociation, timelines, and change-history, all based on experiential cognitive processing of remembered events, leads to an increased awareness of behavioral contingencies and a more sensitive recognition of environmental cues which could serve to lower trait anxiety and increase the sense of internal control. This study reports on within-person and between-group changes in trait anxiety and locus of control as measured on the Spielberger State-Trait Anxiety Inventory and Wallston, Wallston, and DeVallis' Multiple Health Locus of Control immediately following a 21-day residential training in neurolinguistic programming. Significant with-in-person decreases in trait-anxiety scores and increases in internal locus of control scores were observed as predicted. Chance and powerful other locus of control scores were unchanged. Significant differences were noted on trait anxiety and locus of control scores between European and U.S. participants, although change scores were similar for the two groups. These findings are consistent with the hypothesis that this training may lower trait-anxiety scores and increase internal locus of control scores. A matched control group was not available, and follow-up was unfortunately not possible. PMID:1620774

  1. TaXA21-A1 on chromosome 5AL is associated with resistance to multiple pests in wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A quantitative trait locus QYr.osu-5A on the long arm of chromosome 5A in bread wheat (Triticum aestivum L., 2n=6x=42; AABBDD) was previously reported to confer consistent resistance in adult plants to predominant stripe rust races, but the gene causing the quantitative trait locus (QTL) is not know...

  2. Sequence variations in the Boophilus microplus Bm86 locus and implications for immunoprotection in cattle vaccinated with this antigen.

    PubMed

    García-García, J C; Gonzalez, I L; González, D M; Valdés, M; Méndez, L; Lamberti, J; D'Agostino, B; Citroni, D; Fragoso, H; Ortiz, M; Rodríguez, M; de la Fuente, J

    1999-11-01

    Cattle tick infestations constitute a major problem for the cattle industry in tropical and subtropical regions of the world. Traditional control methods have been only partially successful, hampered by the selection of chemical-resistant tick populations. The Boophilus microplus Bm86 protein was isolated from tick gut epithelial cells and shown to induce a protective response against tick infestations in vaccinated cattle. Vaccine preparations including the recombinant Bm86 are used to control cattle tick infestations in the field as an alternative measure to reduce the losses produced by this ectoparasite. The principle for the immunological control of tick infestations relies on a polyclonal antibody response against the target antigen and, therefore, should be difficult to select for tick-resistant populations. However, sequence variations in the Bm86 locus, among other factors, could affect the effectiveness of Bm86-containing vaccines. In the present study we have addressed this issue, employing data obtained with B. microplus strains from Australia, Mexico, Cuba, Argentina and Venezuela. The results showed a tendency in the inverse correlation between the efficacy of the vaccination with Bm86 and the sequence variations in the Bm86 locus (R2 = 0.7). The mutation fixation index in the Bm86 locus was calculated and shown to be between 0.02 and 0.1 amino acids per year. Possible implications of these findings for the immunoprotection of cattle against tick infestations employing the Bm86 antigen are discussed. PMID:10668863

  3. The Salmonella typhimurium mar locus: molecular and genetic analyses and assessment of its role in virulence.

    PubMed Central

    Sulavik, M C; Dazer, M; Miller, P F

    1997-01-01

    The marRAB operon is a regulatory locus that controls multiple drug resistance in Escherichia coli. marA encodes a positive regulator of the antibiotic resistance response, acting by altering the expression of unlinked genes. marR encodes a repressor of marRAB transcription and controls the production of MarA in response to environmental signals. A molecular and genetic study of the homologous operon in Salmonella typhimurium was undertaken, and the role of marA in virulence in a murine model was assessed. Expression of E. coli marA (marAEC) present on a multicopy plasmid in S. typhimurium resulted in a multiple antibiotic resistance (Mar) phenotype, suggesting that a similar regulon exists in this organism. A genomic plasmid library containing S. typhimurium chromosomal sequences was introduced into an E. coli strain that was deleted for the mar locus and contained a single-copy marR'-'lacZ translational fusion. Plasmid clones that contained both S. typhimurium marR (marRSt) and marA (marASt) genes were identified as those that were capable of repressing expression of the fusion and which resulted in a Mar phenotype. The predicted amino acid sequences of MarRSt, MarASt, and MarBSt were 91, 86, and 42% identical, respectively, to the same genes from E. coli, while the operator/promoter region of the operon was 86% identical to the same 98-nucleotide-upstream region in E. coli. The marRAB transcriptional start sites for both organisms were determined by primer extension, and a marRABSt transcript of approximately 1.1 kb was identified by Northern blot analysis. Its accumulation was shown to be inducible by sodium salicylate. Open reading frames flanking the marRAB operon were also conserved. An S. typhimurium marA disruption strain was constructed by an allelic exchange method and compared to the wild-type strain for virulence in a murine BALB/c infection model. No effect on virulence was noted. The endogenous S. typhimurium plasmid that is associated with virulence

  4. Transcriptional Analysis of the Streptococcus pyogenes Salivaricin Locus

    PubMed Central

    Namprachan-Frantz, Phanramphoei; Rowe, Hannah M.; Runft, Donna L.

    2014-01-01

    The sal lantibiotic locus plays an important role in the virulence of Streptococcus pyogenes. Our transcriptional analysis of the sal locus provides new information on the complex regulation of this operon. Transcription of the operon is regulated by a promoter upstream of the operon and by a second internal promoter upstream of the salKRZ genes. Here we identify the location of the internal promoter and provide information on how this promoter is autoregulated by proteins within the locus. We determined by primer extension that the salKR promoter is located within the salY gene and identified several regulatory regions important for expression. The higher activity of the promoter in a salKR deletion strain indicates a role in repression by the SalR response regulator. Further, this promoter had higher activity in a salA deletion strain, implicating corepression or a signaling role for the SalA peptide. Finally, we demonstrate that this promoter can be controlled by host factors. Analysis of transcriptional regulation of this locus provides a better understanding of the function of the sal locus in S. pyogenes pathogenesis. PMID:24244008

  5. Pseudohypoparathyroidism type 1B caused by methylation changes at the GNAS complex locus.

    PubMed

    Poradosu, Sabrina; Bravenboer, Bert; Takatani, Rieko; Jüppner, Harald

    2016-01-01

    Pseudohypoparathyroidism type 1B (PHP1B) consists of a heterogeneous group of disorders characterised by resistance to parathyroid hormone (PTH). There are several different PHP1B subtypes that are all associated with methylation changes at GNAS. These epigenetic changes are caused by maternal deletions in GNAS or STX16, by paternal uniparental isodisomy of chromosome 20q (patUPD20q) or by undefined genetic mutations. The GNAS methylation changes are ultimately responsible for resistance to PTH signalling in the proximal renal tubules. However, there is no PTH resistance in the distal renal tubules nor in bone cells; consequently, patients with PHP1B have reduced urinary calcium excretion and can readily mobilise calcium (and phosphate) from the skeleton. We report a case of a sporadic PHP1B patient with broad GNAS methylation changes that were presumably caused by an unknown genetic mutation outside the GNAS locus. PTH resistance was preceded by several years by autoimmune negative hypothyroidism. Treatment consisted of calcium substitution and calcitriol. PMID:27170606

  6. Accessory Gene Regulator-1 Locus Is Essential for Virulence and Pathogenesis of Clostridium difficile

    PubMed Central

    Odo, Chioma; DuPont, Herbert L.

    2016-01-01

    ABSTRACT Clostridium difficile infection (CDI) is responsible for most of the definable cases of antibiotic- and hospital-associated diarrhea worldwide and is a frequent cause of morbidity and mortality in older patients. C. difficile, a multidrug-resistant anaerobic pathogen, causes disease by producing toxins A and B, which are controlled by an accessory gene regulator (Agr) quorum signaling system. Some C. difficile strains encode two Agr loci in their genomes, designated agr1 and agr2. The agr1 locus is present in all of the C. difficile strains sequenced to date, whereas the agr2 locus is present in a few strains. The functional roles of agr1 and agr2 in C. difficile toxin regulation and pathogenesis were unknown until now. Using allelic exchange, we deleted components of both agr loci and examined the mutants for toxin production and virulence. The results showed that the agr1 mutant cannot produce toxins A and B; toxin production can be restored by complementation with wild-type agr1. Furthermore, the agr1 mutant is able to colonize but unable to cause disease in a murine CDI model. These findings have profound implications for CDI treatment because we have uncovered a promising therapeutic target for the development of nonantibiotic drugs to treat this life-threatening emerging pathogen by targeting the toxins directly responsible for disease. PMID:27531912

  7. Function and evolution of local repeats in the Firre locus

    PubMed Central

    Hacisuleyman, Ezgi; Shukla, Chinmay J.; Weiner, Catherine L.; Rinn, John L.

    2016-01-01

    More than half the human and mouse genomes are comprised of repetitive sequences, such as transposable elements (TEs), which have been implicated in many biological processes. In contrast, much less is known about other repeats, such as local repeats that occur in multiple instances within a given locus in the genome but not elsewhere. Here, we systematically characterize local repeats in the genomic locus of the Firre long noncoding RNA (lncRNA). We find a conserved function for the RRD repeat as a ribonucleic nuclear retention signal that is sufficient to retain an otherwise cytoplasmic mRNA in the nucleus. We also identified a repeat, termed R0, that can function as a DNA enhancer element within the intronic sequences of Firre. Collectively, our data suggest that local repeats can have diverse functionalities and molecular modalities in the Firre locus and perhaps more globally in other lncRNAs. PMID:27009974

  8. Locus coeruleus syndrome as a complication of tectal surgery.

    PubMed

    Kronenburg, Annick; Spliet, Wim G; Broekman, Marike; Robe, Pierre

    2015-01-01

    We describe a case of a 48-year-old woman who underwent a resection of a tectal pilocytic astrocytoma complicated by a sequence of fluctuating consciousness, psychosis with complex hallucinations and lasting sleeping disturbances in which she vividly acts out her dreams. Based on the clinical and anatomical evidence of this case, we propose the term locus coeruleus syndrome to describe this association of iatrogenic symptoms. Along with those of the locus coeruleus, lesions of the dorsal raphe nucleus, ventral tegmentum, substantia nigra pars compacta, the superior colliculus and other peduncular lesions (such as peduncular hallucinosis) are involved in the regulation of sleep-wake/arousal, behaviour, sleeping disorders and rapid eye movement atonia. However, iatrogenic lesion of the locus coeruleus could explain the complications on all levels in our patient. PMID:25903199

  9. Bipartite Structure of the ade3 Locus of SACCHAROMYCES CEREVISIAE

    PubMed Central

    Jones, Elizabeth W.

    1977-01-01

    Forty ade3 mutants were examined with respect to their growth requirements, levels of the tetrahydrofolate interconversion enzymes, and/or map positions. Four deletions were detected. Mutations that result in a requirement for adenine and histidine map in one region of the locus; those which result in a requirement for adenine only map in a quite separate region of the locus, a region not disclosed in previous studies. No correlation was observed between growth properties of the strains and enzyme levels. PMID:324867

  10. Neighborhood Vigilance, Health Locus of Control, and Smoking Abstinence

    PubMed Central

    Reitzel, Lorraine R.; Lahoti, Sejal; Li, Yisheng; Cao, Yumei; Wetter, David W.; Waters, Andrew J.; Vidrine, Jennifer Irvin

    2012-01-01

    Objectives To examine whether health locus of control mediated relations of self-reported neighborhood vigilance and biochemically verified, continuous short-term smoking abstinence among 200 smokers enrolled in a cohort study. Methods A nonparametric bootstrapping procedure was used to assess mediation. Results Health locus of control-chance mediated relations between neighborhood vigilance and smoking abstinence in analyses adjusted for sociodemographics and tobacco dependence (p < .05). Greater vigilance was associated with greater attributions that health was affected by chance, which was associated with a lower likelihood of smoking abstinence. Conclusions Results suggest that neighborhood perceptions influence residents’ attributions for health outcomes, which can affect smoking abstinence. PMID:23985180

  11. History of the discovery of a master locus producing piRNAs: the flamenco/COM locus in Drosophila melanogaster

    PubMed Central

    Coline, Goriaux; Théron, Emmanuelle; Brasset, Emilie; Vaury, Chantal

    2014-01-01

    The discovery of transposable elements (TEs) in the 1950s by B. McClintock implied the existence of cellular regulatory systems controlling TE activity. The discovery of flamenco (flam) an heterochromatic locus from Drosophila melanogaster and its ability to survey several TEs such as gypsy, ZAM, and Idefix contributed to peer deeply into the mechanisms of the genetic and epigenetic regulation of TEs. flam was the first cluster producing small RNAs to be discovered long before RNAi pathways were identified in 1998. As a result of the detailed genetic analyses performed by certain laboratories and of the sophisticated genetic tools they developed, this locus has played a major role in our understanding of piRNA mediated TE repression in animals. Here we review the first discovery of this locus and retrace decades of studies that led to our current understanding of the relationship between genomes and their TE targets. PMID:25136352

  12. History of the discovery of a master locus producing piRNAs: the flamenco/COM locus in Drosophila melanogaster.

    PubMed

    Goriaux, Coline; Théron, Emmanuelle; Brasset, Emilie; Vaury, Chantal

    2014-01-01

    The discovery of transposable elements (TEs) in the 1950s by B. McClintock implied the existence of cellular regulatory systems controlling TE activity. The discovery of flamenco (flam) an heterochromatic locus from Drosophila melanogaster and its ability to survey several TEs such as gypsy, ZAM, and Idefix contributed to peer deeply into the mechanisms of the genetic and epigenetic regulation of TEs. flam was the first cluster producing small RNAs to be discovered long before RNAi pathways were identified in 1998. As a result of the detailed genetic analyses performed by certain laboratories and of the sophisticated genetic tools they developed, this locus has played a major role in our understanding of piRNA mediated TE repression in animals. Here we review the first discovery of this locus and retrace decades of studies that led to our current understanding of the relationship between genomes and their TE targets. PMID:25136352

  13. Two-trait-locus linkage analysis: A powerful strategy for mapping complex genetic traits

    SciTech Connect

    Schork, N.J.; Boehnke, M. ); Terwilliger, J.D.; Ott, J. )

    1993-11-01

    Nearly all diseases mapped to date follow clear Mendelian, single-locus segregation patterns. In contrast, many common familial diseases such as diabetes, psoriasis, several forms of cancer, and schizophrenia are familial and appear to have a genetic component but do not exhibit simple Mendelian transmission. More complex models are required to explain the genetics of these important diseases. In this paper, the authors explore two-trait-locus, two-marker-locus linkage analysis in which two trait loci are mapped simultaneously to separate genetic markers. The authors compare the utility of this approach to standard one-trait-locus, one-marker-locus linkage analysis with and without allowance for heterogeneity. The authors also compare the utility of the two-trait-locus, two-marker-locus analysis to two-trait-locus, one-marker-locus linkage analysis. For common diseases, pedigrees are often bilineal, with disease genes entering via two or more unrelated pedigree members. Since such pedigrees often are avoided in linkage studies, the authors also investigate the relative information content of unilineal and bilineal pedigrees. For the dominant-or-recessive and threshold models that the authors consider, the authors find that two-trait-locus, two-marker-locus linkage analysis can provide substantially more linkage information, as measured by expected maximum lod score, than standard one-trait-locus, one-marker-locus methods, even allowing for heterogeneity, while, for a dominant-or-dominant generating model, one-locus models that allow for heterogeneity extract essentially as much information as the two-trait-locus methods. For these three models, the authors also find that bilineal pedigrees provide sufficient linkage information to warrant their inclusion in such studies. The authors discuss strategies for assessing the significance of the two linkages assumed in two-trait-locus, two-marker-locus models. 37 refs., 1 fig., 4 tabs.

  14. Heterotic Trait Locus (HTL) Mapping Identifies Intra-Locus Interactions That Underlie Reproductive Hybrid Vigor in Sorghum bicolor

    PubMed Central

    Ben-Israel, Imri; Kilian, Benjamin; Nida, Habte; Fridman, Eyal

    2012-01-01

    Identifying intra-locus interactions underlying heterotic variation among whole-genome hybrids is a key to understanding mechanisms of heterosis and exploiting it for crop and livestock improvement. In this study, we present the development and first use of the heterotic trait locus (HTL) mapping approach to associate specific intra-locus interactions with an overdominant heterotic mode of inheritance in a diallel population using Sorghum bicolor as the model. This method combines the advantages of ample genetic diversity and the possibility of studying non-additive inheritance. Furthermore, this design enables dissecting the latter to identify specific intra-locus interactions. We identified three HTLs (3.5% of loci tested) with synergistic intra-locus effects on overdominant grain yield heterosis in 2 years of field trials. These loci account for 19.0% of the heterotic variation, including a significant interaction found between two of them. Moreover, analysis of one of these loci (hDPW4.1) in a consecutive F2 population confirmed a significant 21% increase in grain yield of heterozygous vs. homozygous plants in this locus. Notably, two of the three HTLs for grain yield are in synteny with previously reported overdominant quantitative trait loci for grain yield in maize. A mechanism for the reproductive heterosis found in this study is suggested, in which grain yield increase is achieved by releasing the compensatory tradeoffs between biomass and reproductive output, and between seed number and weight. These results highlight the power of analyzing a diverse set of inbreds and their hybrids for unraveling hitherto unknown allelic interactions mediating heterosis. PMID:22761720

  15. New Amino Acid Regulatory Locus Having Unusual Properties in Heterozygous Merodiploids

    PubMed Central

    Kline, Ellis L.

    1972-01-01

    Spontaneous mutants of Escherichia coli B/r resistant to 5′,5′,5′,-trifluoro-dl-leucine contain defects in a gene which maps to the left of the threonine region. Low-level constitutive expression of the isoleucine-valine and leucine operons is caused by this mutation in haploid strains. This is in contrast to extremely high levels of gene expression in the heterozygous merodiploids (F' wild type/mutant allele). The properties of these mutants define a new locus and suggest that it encodes a subunit protein which is involved in the repression of the structural genes for the branched-chain amino acid pathways. Images PMID:4555405

  16. Comparative analysis of the 100 kb region containing the Pi-k(h) locus between indica and japonica rice lines.

    PubMed

    Kumar, S P; Dalai, V; Singh, N K; Sharma, T R

    2007-02-01

    We have recently cloned a pathogen inducible blast resistance gene Pi-k(h) from the indica rice line Tetep using a positional cloning approach. In this study, we carried out structural organization analysis of the Pi-k(h) locus in both indica and japonica rice lines. A 100 kb region containing 50 kb upstream and 50 kb downstream sequences flanking to the Pi-k(h) locus was selected for the investigation. A total of 16 genes in indica and 15 genes in japonica were predicted and annotated in this region. The average GC content of indica and japonica genes in this region was 53.15% and 49.3%, respectively. Both indica and japonica sequences were polymorphic for simple sequence repeats having mono-, di-, tri-, tetra-, and pentanucleotides. Sequence analysis of the specific blast resistant Pi-k(h) allele of Tetep and the susceptible Pi-k(h) allele of the japonica rice line Nipponbare showed differences in the number and distribution of motifs involved in phosphorylation, resulting in the resistance phenotype in Tetep. PMID:17572362

  17. Genome-Wide Association Study for Type 2 Diabetes in Indians Identifies a New Susceptibility Locus at 2q21

    PubMed Central

    Tabassum, Rubina; Chauhan, Ganesh; Dwivedi, Om Prakash; Mahajan, Anubha; Jaiswal, Alok; Kaur, Ismeet; Bandesh, Khushdeep; Singh, Tejbir; Mathai, Benan John; Pandey, Yogesh; Chidambaram, Manickam; Sharma, Amitabh; Chavali, Sreenivas; Sengupta, Shantanu; Ramakrishnan, Lakshmi; Venkatesh, Pradeep; Aggarwal, Sanjay K.; Ghosh, Saurabh; Prabhakaran, Dorairaj; Srinath, Reddy K.; Saxena, Madhukar; Banerjee, Monisha; Mathur, Sandeep; Bhansali, Anil; Shah, Viral N.; Madhu, Sri Venkata; Marwaha, Raman K.; Basu, Analabha; Scaria, Vinod; McCarthy, Mark I.; Venkatesan, Radha; Mohan, Viswanathan; Tandon, Nikhil; Bharadwaj, Dwaipayan

    2013-01-01

    Indians undergoing socioeconomic and lifestyle transitions will be maximally affected by epidemic of type 2 diabetes (T2D). We conducted a two-stage genome-wide association study of T2D in 12,535 Indians, a less explored but high-risk group. We identified a new type 2 diabetes–associated locus at 2q21, with the lead signal being rs6723108 (odds ratio 1.31; P = 3.32 × 10−9). Imputation analysis refined the signal to rs998451 (odds ratio 1.56; P = 6.3 × 10−12) within TMEM163 that encodes a probable vesicular transporter in nerve terminals. TMEM163 variants also showed association with decreased fasting plasma insulin and homeostatic model assessment of insulin resistance, indicating a plausible effect through impaired insulin secretion. The 2q21 region also harbors RAB3GAP1 and ACMSD; those are involved in neurologic disorders. Forty-nine of 56 previously reported signals showed consistency in direction with similar effect sizes in Indians and previous studies, and 25 of them were also associated (P < 0.05). Known loci and the newly identified 2q21 locus altogether explained 7.65% variance in the risk of T2D in Indians. Our study suggests that common susceptibility variants for T2D are largely the same across populations, but also reveals a population-specific locus and provides further insights into genetic architecture and etiology of T2D. PMID:23209189

  18. Confirmation By QTL mapping Of The Malus Robusta (Cv. Robusta 5) derived powdery mildew resistance gene Pl1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Geneva® apple rootstock breeding program has made extensive use of Malus robusta cv. Robusta 5 as a source of resistance to fire blight. Robusta 5 has also been used as the source of powdery mildew resistance by other breeding programs and a single locus Pl1 has been associated with this resist...

  19. Receptor protein kinase gene encoded at the self-incompatibility locus

    DOEpatents

    Nasrallah, June B.; Nasrallah, Mikhail E.; Stein, Joshua

    1996-01-01

    Described herein is a S receptor kinase gene (SRK), derived from the S locus in Brassica oleracea, having a extracellular domain highly similar to the secreted product of the S-locus glycoprotein gene.

  20. Coordinated forms of noradrenergic plasticity in the locus coeruleus and primary auditory cortex

    PubMed Central

    Martins, Ana Raquel O.; Froemke, Robert C.

    2015-01-01

    The cerebral cortex is plastic and represents the world according to the significance of sensory stimuli. However, cortical networks are embodied within complex circuits including neuromodulatory systems such as the noradrenergic locus coeruleus, providing information about internal state and behavioral relevance. While norepinephrine is important for cortical plasticity, it is unknown how modulatory neurons themselves respond to changes of sensory input. Here we examine how locus coeruleus neurons are modified by experience, and the consequences of locus coeruleus plasticity on cortical representations and sensory perception. We made whole-cell recordings from rat locus coeruleus and primary auditory cortex (AI), pairing sounds with locus coeruleus activation. Although initially unresponsive, locus coeruleus neurons developed and maintained auditory responses afterwards. Locus coeruleus plasticity induced changes in AI responses lasting at least hours and improved auditory perception for days to weeks. Our results demonstrate that locus coeruleus is highly plastic, leading to substantial changes in regulation of brain state by norepinephrine. PMID:26301326

  1. Ink4-Arf locus in cancer and aging.

    PubMed

    Sherr, Charles J

    2012-01-01

    Three tumor suppressor genes at the small (<50 kb) INK4-ARF (CDKN2A/B) locus on human chromosome 9p21 coordinate a signaling network that depends on the activities of the retinoblastoma (RB) protein and the p53 transcription factor. Disruption of this circuitry, frequently by codeletion of INK4-ARF, is a hallmark of cancer, begging the question of why the intimate genetic linkage of these tumor suppressor genes has been maintained in mammals despite the risk of their coinactivation. The INK4-ARF locus is not highly expressed under normal physiologic conditions in young mammals, but its induction becomes more pronounced as animals age. Notably, INK4-ARF is actively silenced en bloc in embryonic, fetal, and adult stem cells but becomes poised to respond to oncogenic stress signals as stem cells lose their self-renewal capacity and differentiate, thereby providing a potent barrier to tumor formation. Epigenetic remodeling of the locus as a whole provides a mechanism for coordinating the activities of RB and p53. A hypothesis is that the INK4-ARF locus may have evolved to physiologically restrict the self-renewal capacities and numbers of stem and progenitor cells with the attendant consequence of limiting tissue regenerative capacity, particularly as animals age. Deletion of INK4-ARF contributes to the aberrant self-renewal capacity of tumor cells and occurs frequently in many forms of human cancer. PMID:22960768

  2. Locus of Control and Human Capital Investment Revisited

    ERIC Educational Resources Information Center

    Cebi, Merve

    2007-01-01

    This paper examines the effect of teenagers' outlooks--specified as their locus of control--on educational attainment and labor market outcomes. I replicate the study of Coleman and DeLeire (2003) and test the predictions of their theoretical model using a different data set--National Longitudinal Survey of Youth (NLSY). The findings fail to…

  3. Relationship between Locus of Control and Health-Related Variables

    ERIC Educational Resources Information Center

    Graffeo, Lisa Cotlar; Silvestri, Lynette

    2006-01-01

    Locus of Control (LOC) deals with an individual's personal attribution of successful or failure. Those with internal LOC believe that events in their lives are under their personal control while individuals with external LOC feel that their lives are dominated by the environment. The theory has been applied to achievement and health-related issues…

  4. Should Farmers' Locus of Control Be Used in Extension?

    ERIC Educational Resources Information Center

    Nuthall, Peter L.

    2010-01-01

    To explore whether Farmers' Locus of Control (LOC) could be useful in agricultural extension programmes to improve managerial ability. This test records a farmer's belief in her/his control over production outcomes. A mail survey of 2300 New Zealand farmers was used to obtain a range of variables, and to measure their LOC using a question set…

  5. Changes in Perceived Locus of Control during Basic Training.

    ERIC Educational Resources Information Center

    Vickers, Ross R., Jr.; Conway, Terry L.

    Basic Training (BT) is designed to prepare recruits for their new role as members of the military. The psychological effects of this experience can have important implications for recruits' later effectiveness in the military. Locus of control is one psychological construct which can be important for overall psychological and behavioral adaptation…

  6. Attitudes toward Nutrition, Locus of Control and Smoking Behavior.

    ERIC Educational Resources Information Center

    Corfield, V. Kilian; And Others

    Research has shown that many behaviors previously thought to be purely psychological in origin do, in fact, have a physiological basis. To examine the relationship of smoking behavior to locus of control, and to attitudes toward, knowledge about, and behavior with respect to nutrition, 116 Canadian undergraduate students completed the Nutrition…

  7. Fetal Health Locus of Control Scale: Development and Validation.

    ERIC Educational Resources Information Center

    Labs, Sharon M.; Wurtele, Sandy K.

    1986-01-01

    Describes development of the Fetal Health Locus of Control scale, the scale's utility in predicting maternal health-related behavior during pregnancy, normative data, and information on factor structure and internal consistency. Reports that cigarette and caffeine consumption during pregnancy, and women's intentions to participate in prepared…

  8. Comparison of Locus of Control with Levels of Creativity.

    ERIC Educational Resources Information Center

    Kneipp, Karen B.; Gadzella, Bernadette M.

    This study was undertaken to determine whether external locus of control orientation was significantly negatively correlated with levels of creativity. Subjects were 13 male and 13 female undergraduate students enrolled in psychology classes at a southwestern university. Mean age of the subjects was 28.6. Instruments used were Levenson's (1972) I…

  9. Locus of Control of Reinforcement and Responsiveness to Social Influence.

    ERIC Educational Resources Information Center

    Doctor, Ronald M.; Marziani, A. William

    Rotter's (1966) "control of reinforcement" construct is a dimension of belief or expectancy about the locus of reinforcing consequences for behavior. A generalized disposition is represented which ascribes reinforcement contingencies to either "external" (and, hence, uncontrollable) factors or to "internal" sources in which case the individual…

  10. Dimensions of Locus of Control: Impact of Early Educational Experiences.

    ERIC Educational Resources Information Center

    Stephens, Mark W.

    A study was conducted to: (1) assess the equivalence of the Nowicki Strickland Locus of Control Scale for Children, the Stephens-Delys Reinforcement Contingency Interview, and the Gruen-Korte-Stephens test and the construct validity of each; and (2) investigate the impact on IE of the open classroom Follow Through program sponsored by the…

  11. Locus of Control and Helplessness: Gender Differences among Bereaved Parents

    ERIC Educational Resources Information Center

    Rubinstein, Gidi

    2004-01-01

    This study investigated locus of control (LC) and hopelessness (H) among 25 pairs of bereaved parents, who lost their children in the Arab--Israeli conflict, and 25 pairs of demographically matched non-bereaved parents (mean age 53). Four of the 5 hypotheses were supported by results. LC was significantly more external and H was significantly…

  12. Children's Locus of Control and Intrinsically Motivated Reading.

    ERIC Educational Resources Information Center

    Whitney, Patricia

    A study investigated the relationship between locus of control and intrinsically motivated reading for children. The entire sixth grade, totalling 53 students, of a parochial school in San Francisco was administered the Children's Nowicki-Strickland Internal-External Control Scale. A free-choice paperback reading rack provided the measure for…

  13. Inferring relationships between pairs of individuals from locus heterozygosities

    PubMed Central

    Presciuttini, Silvano; Toni, Chiara; Tempestini, Elena; Verdiani, Simonetta; Casarino, Lucia; Spinetti, Isabella; Stefano, Francesco De; Domenici, Ranieri; Bailey-Wilson, Joan E

    2002-01-01

    Background The traditional exact method for inferring relationships between individuals from genetic data is not easily applicable in all situations that may be encountered in several fields of applied genetics. This study describes an approach that gives affordable results and is easily applicable; it is based on the probabilities that two individuals share 0, 1 or both alleles at a locus identical by state. Results We show that these probabilities (zi) depend on locus heterozygosity (H), and are scarcely affected by variation of the distribution of allele frequencies. This allows us to obtain empirical curves relating zi's to H for a series of common relationships, so that the likelihood ratio of a pair of relationships between any two individuals, given their genotypes at a locus, is a function of a single parameter, H. Application to large samples of mother-child and full-sib pairs shows that the statistical power of this method to infer the correct relationship is not much lower than the exact method. Analysis of a large database of STR data proves that locus heterozygosity does not vary significantly among Caucasian populations, apart from special cases, so that the likelihood ratio of the more common relationships between pairs of individuals may be obtained by looking at tabulated zi values. Conclusions A simple method is provided, which may be used by any scientist with the help of a calculator or a spreadsheet to compute the likelihood ratios of common alternative relationships between pairs of individuals. PMID:12441003

  14. The Locus of the Focus of a Rolling Parabola

    ERIC Educational Resources Information Center

    Agarwal, Anurag; Marengo, James

    2010-01-01

    The catenary is usually introduced as the shape assumed by a hanging flexible cable. This is a "physical" description of a catenary. In this article we give a "geometrical" description of a catenary. Specifically we show that the catenary is the locus of the focus of a certain parabola as it rolls on the x-axis.

  15. The Influence of Locus of Control on Student Financial Behavior

    ERIC Educational Resources Information Center

    Britt, Sonya; Cumbie, Julie A.; Bell, Mary M.

    2013-01-01

    Data on psychological influences of financial behaviors has not been well addressed in student populations, which is concerning given the high levels of general and financial stress experienced by college students. The findings of this study indicate that college students with an external locus of control exhibit the worst financial behaviors.…

  16. Relationship Among Locus of Control, Self-concept, and Anxiety

    ERIC Educational Resources Information Center

    Donovan, Dennis M.; And Others

    1975-01-01

    The purpose of the present research was to replicate O'Leary, et al.'s previous findings (EJ 100 528) and to test the hypothesis that the correlation between Rotter's Locus of Control scale and the Taylor Manifest Anxiety scale was moderated by neuroticism and negativism toward self. (Author/RK)

  17. Dealing with Malfunction: Locus of Control in Web-Conferencing

    ERIC Educational Resources Information Center

    Klebl, Michael

    2014-01-01

    This paper considers how students deal with malfunctions that occur during the use of web conferencing systems in learning arrangements. In a survey among participants in online courses that make use of a web-conferencing system (N = 129), the relationship between a preference for internal or external locus of control and the perception of…

  18. Relationships among Impulsiveness, Locus of Control, Sex, and Music Practice

    ERIC Educational Resources Information Center

    Miksza, Peter

    2006-01-01

    This study is an investigation of relationships among impulsiveness, locus of control, sex, observed practice behaviors, practice effectiveness, and self-reported practice habits in a sample of 40 college brass players. Practice effectiveness was defined by the amount of change in pretest and posttest performance achievement scores over one…

  19. Molecular genetic analysis of the Phaseolus vulgaris P locus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Common bean market classes are distinguished by their many seed colors, patterns, and size. At least 23 genes, acting independently or in an epistatic manner, affect the seed coat color and pattern. The P locus which is described as the “ground factor” by Emerson, has multiple alleles and controls a...

  20. Marathon Group: Changes in Perceived Locus of Control

    ERIC Educational Resources Information Center

    Foulds, Melvin L.; And Others

    1974-01-01

    Fifteen college students participated in a 24-hour marathon group and responded to the Internal-External Scale immediately before and after the experience. The results disclosed significant positive change at the .001 level in perceived locus of internal-external control of reinforcement expectancies in the direction of increased internality.…

  1. Exploring Learner Autonomy: Language Learning Locus of Control in Multilinguals

    ERIC Educational Resources Information Center

    Peek, Ron

    2016-01-01

    By using data from an online language learning beliefs survey (n?=?841), defining language learning experience in terms of participants' multilingualism, and using a domain-specific language learning locus of control (LLLOC) instrument, this article examines whether more experienced language learners can also be seen as more autonomous language…

  2. Effect of Color-coding on Locus of Control.

    ERIC Educational Resources Information Center

    Moore, David M.; Dwyer, Francis M.

    This study examined the effects of color on information processing strategies of internal and external locus of control learners. Specific objectives were to: (1) examine the instructional effectiveness of two types of visualized instruction in facilitating achievement for students with different learning styles; (2) determine whether an…

  3. Job Satisfaction and Locus of Control in an Academic Setting

    ERIC Educational Resources Information Center

    Stachowiak, Bonni J.

    2010-01-01

    This study explored any relationships that existed between faculty members' locus of control and job satisfaction at a small, private, faith-based university. Two demographic variables were also analyzed in the findings: number of years teaching in higher education and tenure status. The job satisfaction instrument used was the Job in General…

  4. Affective Relationship, Locus of Control, and Imitative Behavior

    ERIC Educational Resources Information Center

    Finch, A. J., Jr.; And Others

    1975-01-01

    The effects of the affective relationship between a model and observer and locus of control on imitative behavior were investigated using a simple imitative task with 28 boys as subjects. Results indicated the need to control the affective relationship between model and observer and support Bandura's position that imitative behavior is primarily…

  5. DSP4, a selective neurotoxin for the locus coeruleus noradrenergic system. A review of its mode of action.

    PubMed

    Ross, Svante B; Stenfors, Carina

    2015-01-01

    DSP4 (N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine hydrochloride) is a selective neurotoxin for the locus coeruleus noradrenergic system in the rodent and bird brain. It readily passes the blood-brain barrier and cyclizes to a reactive aziridinium derivative that is accumulated into the noradrenergic nerve terminals via the noradrenaline transporter. DSP4 is also an irreversible inhibitor of this transporter. Within the nerve terminals the aziridinium derivative reacts with unknown vital cellular components, destroying the terminals. At the dose 50 mg/kg i.p. this is characterized by a rapid and long-lasting loss of noradrenaline and a slower decrease in the dopamine-β-hydroxylase enzyme activity and immunoreactivity in the regions innervated from locus coeruleus. The tissue level of noradrenaline is reduced to 10-30% of the normal value. The extraneuronal concentration is, on the other hand, increased due to inflow from non-lesioned regions. Like the peripheral sympathetic nerves the non-locus coeruleus noradrenergic systems in the rodent brain is resistant to the neurotoxic action of DSP4. Serotoninergic and dopaminergic nerves are only slightly or not at all affected by DSP4. The neurotoxic effect is counteracted by pretreatment with noradrenaline uptake inhibitors (e.g., desipramine). MAO-B inhibitors of the N-propargylamine type (e.g., selegiline) also counteract the DSP4-induced neurotoxicity with another, yet unknown mechanism. Because of its selectivity for the locus coeruleus system DSP4 is a useful tool in studies of the functional role of this noradrenergic system in the brain. PMID:24964753

  6. Locus of Control, Field Dependence, and Stress Reactivity in Young Adult Males.

    ERIC Educational Resources Information Center

    Schweibinz, Janet S.

    This study examined the potential relationships between locus of control, field dependence, and stress reactivity in a sample of young adult males (N=40). Locus of control, field dependence, and stress reactivity were measured by the Rotter Locus of Control Scale, the Embedded Figures Test, and the Life Events Survey, respectively. State stress…

  7. Locus of Control, Television Viewing, and Eating Disorder Symptomatology in Young Females.

    ERIC Educational Resources Information Center

    Fouts, Gregory; Vaughan, Kimberley

    2002-01-01

    Assesses the effects of locus of control and television watching on eating disorder symptomatology in girls between the ages 10-17 years. Girls with an external locus of control had significantly greater eating disorder symptomatology. Girls who watched higher amounts of television and had an external locus of control had significantly greater…

  8. Reframing Student Affairs Leadership: An Analysis of Organizational Frames of Reference and Locus of Control

    ERIC Educational Resources Information Center

    Tull, Ashley; Freeman, Jerrid P.

    2011-01-01

    Examined in this study were the identified frames of reference and locus of control used by 478 student affairs administrators. Administrator responses were examined to identify frames of reference most commonly used and their preference order. Locus of control most commonly used and the relationship between frames of reference and locus of…

  9. Development and Validation of the Health Locus of Control (HLC) Scale

    ERIC Educational Resources Information Center

    Wallston, Barbara Strudler; And Others

    1976-01-01

    The Health Locus of Control (HLC) Scale is an area-specific measure of expectancies regarding locus of control developed for prediction of health-related behavior. Two experiments show discriminant validity of the HLC in contrast with Rotter's Internal-External Locus of Control Scale. Normative data on the HLC are provided. (Author)

  10. Locus of Control and Attitude toward Eating in a Female College Population.

    ERIC Educational Resources Information Center

    Groth-Marnat, Gary; Scumaker, Jack F.

    1988-01-01

    Investigated relationship between locus of control and attitude to food intake in 101 female college students. Results indicated that locus of control was unable to predict attitudes toward eating and fear of becoming overweight. Thesis that locus of control would be related to attitude toward food intake was not supported. (Author/NB)

  11. Antecedents and Correlates of Locus of Control in High School Students.

    ERIC Educational Resources Information Center

    Masi, Wendy Segal

    This study dealt with the perceived parental attitudes of affection, physical contact, consistency-trust, security and perceived parental locus of control orientation as possible determinants of locus of control orientation in high school seniors. A second phase was concerned with the relationship of perceived parental locus of control orientation…

  12. Rasch Analysis of the Locus-of-Hope Scale. Brief Report

    ERIC Educational Resources Information Center

    Gadiana, Leny G.; David, Adonis P.

    2015-01-01

    The Locus-of-Hope Scale (LHS) was developed as a measure of the locus-of-hope dimensions (Bernardo, 2010). The present study adds to the emerging literature on locus-of-hope by assessing the psychometric properties of the LHS using Rasch analysis. The results from the Rasch analyses of the four subscales of LHS provided evidence on the…

  13. A Study of Reward Preference in Taiwanese Gifted and Nongifted Students with Differential Locus of Control

    ERIC Educational Resources Information Center

    Wu, Su Chen; Elliott, Robert T.

    2008-01-01

    The purpose of the study was to investigate whether gifted and nongifted students' preferences for different types of reward were affected by differential locus of control. In total, 181 gifted and 107 nongifted junior high school students in Taiwan participated. The Nowicki-Strickland Locus of Control Scale was used as a measure of locus of…

  14. Locus of Control in Offenders and Alleged Offenders with Learning Disabilities

    ERIC Educational Resources Information Center

    Goodman, Wendy; Leggett, Janice; Garrett, Tanya

    2007-01-01

    Locus of control can be a useful measure of treatment outcome in offenders from the general population. However, there is little information regarding locus of control and offenders with learning disabilities. Existing measures of locus of control use complex language and abstract ideas that may not be accessible to individuals in this group. A…

  15. On the Relation of Locus of Control and L2 Reading and Writing Achievement

    ERIC Educational Resources Information Center

    Ghonsooly, Behzad; Shirvan, Majid Elahi

    2011-01-01

    Locus of control, a psychological construct, has been the focus of attention in recent decades. Psychologists have discussed the effect of locus of control on achieving life goals in social/psychological interactions. While learning a foreign language involves both social interactions and psychological processes, the role and relation of locus of…

  16. Allele-specific locus binding and genome editing by CRISPR at the p16INK4a locus

    PubMed Central

    Fujita, Toshitsugu; Yuno, Miyuki; Fujii, Hodaka

    2016-01-01

    The clustered regularly interspaced short palindromic repeats (CRISPR) system has been adopted for a wide range of biological applications including genome editing. In some cases, dissection of genome functions requires allele-specific genome editing, but the use of CRISPR for this purpose has not been studied in detail. In this study, using the p16INK4a gene in HCT116 as a model locus, we investigated whether chromatin states, such as CpG methylation, or a single-nucleotide gap form in a target site can be exploited for allele-specific locus binding and genome editing by CRISPR in vivo. First, we showed that allele-specific locus binding and genome editing could be achieved by targeting allele-specific CpG-methylated regions, which was successful for one, but not all guide RNAs. In this regard, molecular basis underlying the success remains elusive at this stage. Next, we demonstrated that an allele-specific single-nucleotide gap form could be employed for allele-specific locus binding and genome editing by CRISPR, although it was important to avoid CRISPR tolerance of a single nucleotide mismatch brought about by mismatched base skipping. Our results provide information that might be useful for applications of CRISPR in studies of allele-specific functions in the genomes. PMID:27465215

  17. Development of candidate gene markers associated to common bacterial blight resistance in common bean.

    PubMed

    Shi, Chun; Yu, Kangfu; Xie, Weilong; Perry, Gregory; Navabi, Alireza; Pauls, K Peter; Miklas, Phillip N; Fourie, Deidré

    2012-11-01

    Common bacterial blight (CBB), caused by Xanthomonas axonopodis pv. phaseoli (Xap), is a major yield-limiting factor of common bean (Phaseolus vulgaris L.) production around the world. Two major CBB-resistant quantitative trait loci (QTL), linked to the sequence characterized amplified region markers BC420 and SU91, are located at chromosomes 6 and 8, respectively. Using map-based cloning approach, four bacterial artificial chromosome (BAC) clones from the BC420-QTL locus and one BAC clone containing SU91 were sequenced by Roche 454 technique and subsequently assembled using merged assemblies from three different programs. Based on the quality of the assembly, only the sequences of BAC 32H6 and 4K7 were used for candidate gene marker (CGM) development and candidate gene (CG) selection. For the BC420-QTL locus, 21 novel genes were predicted in silico by FGENESH using Medicago gene model, whereas 16 genes were identified in the SU91-QTL locus. For each putative gene, one or more primer pairs were designed and tested in the contrasting near isogenic lines. Overall, six and nine polymorphic markers were found in the SU91- and BC420-QTL loci, respectively. Afterwards, association mapping was conducted in a breeding population of 395 dry bean lines to discover marker-trait associations. Two CGMs per each locus showed better association with CBB resistance than the BC420 and SU91 markers, which include BC420-CG10B and BC420-CG14 for BC420_QTL locus, and SU91-CG10 and SU91-CG11 for SU91_QTL locus. The strong associations between CBB resistance and the CGs 10 and 14 from BC420_QTL locus and the CGs 10 and 11 from SU91_QTL locus indicate that the genes 10 and 14 from the BC420 locus are potential CGs underlying the BC420_QTL locus, whereas the genes 10 and 11 from the SU91 locus are potential CGs underlying the SU91_QTL locus. The superiority of SU91-CG11 was further validated in a recombinant inbred line population Sanilac × OAC 09-3. Thus, co-dominant CGMs, BC420-CG14 and

  18. Parallel Evolution of Bacillus thuringiensis Toxin Resistance in Lepidoptera

    PubMed Central

    Baxter, Simon W.; Badenes-Pérez, Francisco R.; Morrison, Anna; Vogel, Heiko; Crickmore, Neil; Kain, Wendy; Wang, Ping; Heckel, David G.; Jiggins, Chris D.

    2011-01-01

    Despite the prominent and worldwide use of Bacillus thuringiensis (Bt) insecticidal toxins in agriculture, knowledge of the mechanism by which they kill pests remains incomplete. Here we report genetic mapping of a membrane transporter (ABCC2) to a locus controlling Bt Cry1Ac toxin resistance in two lepidopterans, implying that this protein plays a critical role in Bt function. PMID:21840855

  19. Resistance-Resistant Antibiotics

    PubMed Central

    Oldfield, Eric; Feng, Xinxin

    2014-01-01

    New antibiotics are needed because as drug resistance is increasing, the introduction of new antibiotics is decreasing. Here, we discuss six possible approaches to develop ‘resistance-resistant’ antibiotics. First, multi-target inhibitors in which a single compound inhibits more than one target may be easier to develop than conventional combination therapies with two new drugs. Second, inhibiting multiple targets in the same metabolic pathway is expected to be an effective strategy due to synergy. Third, discovering multiple-target inhibitors should be possible by using sequential virtual screening. Fourth, re-purposing existing drugs can lead to combinations of multi-target therapeutics. Fifth, targets need not be proteins. Sixth, inhibiting virulence factor formation and boosting innate immunity may also lead to decreased susceptibility to resistance. Although it is not possible to eliminate resistance, the approaches reviewed here offer several possibilities for reducing the effects of mutations and in some cases suggest that sensitivity to existing antibiotics may be restored, in otherwise drug resistant organisms. PMID:25458541

  20. Genetic characterization and targeted mapping of a Triticum timopheevii-dervied powdery mildew resistance gene

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There are five alleles conferring race-specific resistance to powdery mildew (caused by Blumeria graminis f. sp. tritici) at the Pm1 locus on the long arm of chromosome 7A of wheat (Triticum aestivum. L). A dominant powdery mildew resistance gene transferred to the hexaploid germplasm line NC99BGTAG...

  1. Characterization of rice blast resistance gene Pi61(t) in rice germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Identification of resistance (R) genes to races of Magnaporthe oryzae in rice germplasm is essential for the development of rice cultivars with long lasting blast resistance. In the present study, one major quantitative trait locus, qPi93-3, was fine mapped using a recombinant inbred line (RIL), F8 ...

  2. A spontaneous segmental deletion from chromosome arm 3DL enhances Fusarium head blight resistance in wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Much effort has been directed at identifying sources of resistance to Fusarium head blight (FHB) in wheat. We sought to identify molecular markers for what we hypothesized was a new major FHB resistance locus originating from the wheat cultivar 'Freedom' and introgressed into the susceptible wheat c...

  3. A meta-analytic examination of work and general locus of control.

    PubMed

    Wang, Qiang; Bowling, Nathan A; Eschleman, Kevin J

    2010-07-01

    The current meta-analysis examined the hypothesized consequences of work and general locus of control. As expected, work locus of control generally yielded stronger relationships with work-related criteria (e.g., job satisfaction, affective commitment, and burnout) than general locus of control. We also found some evidence that general locus of control yielded relatively stronger relationships with general criteria (e.g., life satisfaction, affective commitment, and burnout). Regression analysis found several unique effects for both work and general locus of control. PMID:20604595

  4. Competing for Iron: Duplication and Amplification of the isd Locus in Staphylococcus lugdunensis HKU09-01 Provides a Competitive Advantage to Overcome Nutritional Limitation

    PubMed Central

    Heilbronner, Simon; Brozyna, Jeremy R.; Heinrichs, David E.; Skaar, Eric P.; Peschel, Andreas; Foster, Timothy J.

    2016-01-01

    Staphylococcus lugdunensis is a coagulase negative bacterial pathogen that is particularly associated with severe cases of infectious endocarditis. Unique amongst the coagulase-negative staphylococci, S. lugdunensis harbors an iron regulated surface determinant locus (isd). This locus facilitates the acquisition of heme as a source of nutrient iron during infection and allows iron limitation caused by “nutritional immunity” to be overcome. The isd locus is duplicated in S. lugdunensis HKU09-01 and we show here that the duplication is intrinsically unstable and undergoes accordion-like amplification and segregation leading to extensive isd copy number variation. Amplification of the locus increased the level of expression of Isd proteins and improved binding of hemoglobin to the cell surface of S. lugdunensis. Furthermore, Isd overexpression provided an advantage when strains were competing for a limited amount of hemoglobin as the sole source of iron. Gene duplications and amplifications (GDA) are events of fundamental importance for bacterial evolution and are frequently associated with antibiotic resistance in many species. As such, GDAs are regarded as evolutionary adaptions to novel selective pressures in hostile environments pointing towards a special importance of isd for S. lugdunensis. For the first time we show an example of a GDA that involves a virulence factor of a Gram-positive pathogen and link the GDA directly to a competitive advantage when the bacteria were struggling with selective pressures mimicking “nutritional immunity”. PMID:27575058

  5. Competing for Iron: Duplication and Amplification of the isd Locus in Staphylococcus lugdunensis HKU09-01 Provides a Competitive Advantage to Overcome Nutritional Limitation.

    PubMed

    Heilbronner, Simon; Monk, Ian R; Brozyna, Jeremy R; Heinrichs, David E; Skaar, Eric P; Peschel, Andreas; Foster, Timothy J

    2016-08-01

    Staphylococcus lugdunensis is a coagulase negative bacterial pathogen that is particularly associated with severe cases of infectious endocarditis. Unique amongst the coagulase-negative staphylococci, S. lugdunensis harbors an iron regulated surface determinant locus (isd). This locus facilitates the acquisition of heme as a source of nutrient iron during infection and allows iron limitation caused by "nutritional immunity" to be overcome. The isd locus is duplicated in S. lugdunensis HKU09-01 and we show here that the duplication is intrinsically unstable and undergoes accordion-like amplification and segregation leading to extensive isd copy number variation. Amplification of the locus increased the level of expression of Isd proteins and improved binding of hemoglobin to the cell surface of S. lugdunensis. Furthermore, Isd overexpression provided an advantage when strains were competing for a limited amount of hemoglobin as the sole source of iron. Gene duplications and amplifications (GDA) are events of fundamental importance for bacterial evolution and are frequently associated with antibiotic resistance in many species. As such, GDAs are regarded as evolutionary adaptions to novel selective pressures in hostile environments pointing towards a special importance of isd for S. lugdunensis. For the first time we show an example of a GDA that involves a virulence factor of a Gram-positive pathogen and link the GDA directly to a competitive advantage when the bacteria were struggling with selective pressures mimicking "nutritional immunity". PMID:27575058

  6. Overexpression of the pathogen-inducible wheat TaWRKY45 gene confers disease resistance to multiple fungi in transgenic wheat plants.

    PubMed

    Bahrini, Insaf; Ogawa, Taiichi; Kobayashi, Fuminori; Kawahigashi, Hiroyuki; Handa, Hirokazu

    2011-12-01

    Recently we cloned and characterized the gene for the wheat transcription factor TaWRKY45 and showed that TaWRKY45 was upregulated in response to benzothiadiazole (BTH) and Fusarium head blight (FHB) and that its overexpression conferred enhanced resistance against F. graminearum. To characterize the functional role of TaWRKY45 in the disease resistance of wheat, in the present study we conducted expression analyses of TaWRKY45 with inoculations of powdery mildew and leaf rust and evaluated TaWRKY45-overexpressing wheat plants for resistance to these diseases. TaWRKY45 was upregulated in response to infections with Blumeria graminis, a causal fungus for powdery mildew, and Puccinia triticina, a causal fungus for leaf rust. Constitutive overexpression of the TaWRKY45 transgene conferred enhanced resistance against these two fungi on transgenic wheat plants grown under greenhouse conditions. However, the expression of two resistance-related genes, Pm3 and Lr34, was not induced by the inoculation with powdery mildew in TaWRKY45-overexpressing wheat plants. These results suggest that TaWRKY45 is involved in the defense responses for multiple fungal diseases in wheat but that resistance involving TaWRKY45 differs from at least Pm3 and/or Lr34-related resistance. Our present and previous studies indicate that TaWRKY45 may be potentially utilized to improve a wide range of disease resistance in wheat. PMID:23136468

  7. Overexpression of the pathogen-inducible wheat TaWRKY45 gene confers disease resistance to multiple fungi in transgenic wheat plants

    PubMed Central

    Bahrini, Insaf; Ogawa, Taiichi; Kobayashi, Fuminori; Kawahigashi, Hiroyuki; Handa, Hirokazu

    2011-01-01

    Recently we cloned and characterized the gene for the wheat transcription factor TaWRKY45 and showed that TaWRKY45 was upregulated in response to benzothiadiazole (BTH) and Fusarium head blight (FHB) and that its overexpression conferred enhanced resistance against F. graminearum. To characterize the functional role of TaWRKY45 in the disease resistance of wheat, in the present study we conducted expression analyses of TaWRKY45 with inoculations of powdery mildew and leaf rust and evaluated TaWRKY45-overexpressing wheat plants for resistance to these diseases. TaWRKY45 was upregulated in response to infections with Blumeria graminis, a causal fungus for powdery mildew, and Puccinia triticina, a causal fungus for leaf rust. Constitutive overexpression of the TaWRKY45 transgene conferred enhanced resistance against these two fungi on transgenic wheat plants grown under greenhouse conditions. However, the expression of two resistance-related genes, Pm3 and Lr34, was not induced by the inoculation with powdery mildew in TaWRKY45-overexpressing wheat plants. These results suggest that TaWRKY45 is involved in the defense responses for multiple fungal diseases in wheat but that resistance involving TaWRKY45 differs from at least Pm3 and/or Lr34-related resistance. Our present and previous studies indicate that TaWRKY45 may be potentially utilized to improve a wide range of disease resistance in wheat. PMID:23136468

  8. Drug Resistance

    MedlinePlus

    HIV Treatment Drug Resistance (Last updated 3/1/2016; last reviewed 3/1/2016) Key Points As HIV multiplies in the ... the risk of drug resistance. What is HIV drug resistance? Once a person becomes infected with HIV, ...

  9. Antibiotic Resistance

    MedlinePlus

    ... lives. But there is a growing problem of antibiotic resistance. It happens when bacteria change and become able ... resistant to several common antibiotics. To help prevent antibiotic resistance Don't use antibiotics for viruses like colds ...

  10. Refined localization of the Prieto-syndrome locus

    SciTech Connect

    Martinez, F.; Prieto, F.; Gal, A.

    1996-07-12

    PRS designates the locus for a syndromal form of X-linked mental retardation (Prieto syndrome) characterized by minor facial anomalies, ear malformation, abnormal growth of teeth, clinodactyly, sacral dimple, patellar luxation, malformation of lower limbs, abnormalities of the fundus of the eye, and subcortical cerebral atrophy. Linkage analysis localized the disease locus between DXS84 (Xp21.1) and DXS255. Here we present additional linkage data that provide further support and refinement of this localization. Individual III-18 gave birth to a male, currently aged 2 7/12 years, who clearly shows delayed psychomotor development. He began to walk at 23 months and his speech is delayed. In addition, he shows the characteristic facial anomalies, {open_quotes}dysplastic{close_quotes} ears, sacral dimple, and clinodactyly, as do all other affected males in this family. 7 refs., 1 tab.

  11. Cross-species identification of Mendel's I locus.

    PubMed

    Armstead, Ian; Donnison, Iain; Aubry, Sylvain; Harper, John; Hörtensteiner, Stefan; James, Caron; Mani, Jan; Moffet, Matt; Ougham, Helen; Roberts, Luned; Thomas, Ann; Weeden, Norman; Thomas, Howard; King, Ian

    2007-01-01

    A key gene involved in plant senescence, mutations of which partially disable chlorophyll catabolism and confer stay-green leaf and cotyledon phenotypes, has been identified in Pisum sativum, Arabidopsis thaliana, and Festuca pratensis by using classical and molecular genetics and comparative genomics. A stay-green locus in F. pratensis is syntenically equivalent to a similar stay-green locus on rice chromosome 9. Functional testing in Arabidopsis of a homolog of the rice candidate gene revealed (i) senescence-associated gene expression and (ii) a stay-green phenotype after RNA interference silencing. Genetic mapping in pea demonstrated cosegregation with the yellow/green cotyledon polymorphism (I/i) first reported by Gregor Mendel in 1866. PMID:17204643

  12. Teacher psychological needs, locus of control and engagement.

    PubMed

    Betoret, Fernando Doménech

    2013-01-01

    This study examines the relationships among psychological needs, locus of control and engagement in a sample of 282 Spanish secondary school teachers. Nine teacher needs were identified based on the study of Bess (1977) and on the Self-Determination Theory (Deci & Ryan, 1985, 2000, 2002). Self-report questionnaires were used to measure the construct selected for this study and their interrelationships were examined by conducting hierarchical regression analyses. An analysis of teacher responses using hierarchical regression reveals that psychological needs have significant positive effects on the three engagement dimensions (vigor, dedication and absorption). Furthermore, the results show the moderator role played by locus of control in the relationship between teacher psychological needs and the so-called core of engagement (vigor and dedication). Finally, practical implications are discussed. PMID:23866223

  13. The locus of microRNA-10b

    PubMed Central

    Biagioni, Francesca; Bossel Ben-Moshe, Noa; Fontemaggi, Giulia; Yarden, Yosef; Domany, Eytan; Blandino, Giovanni

    2013-01-01

    Contemporary microRNA research has led to significant advances in our understanding of the process of tumorigenesis. MicroRNAs participate in different events of a cancer cell’s life, through their ability to target hundreds of putative transcripts involved in almost every cellular function, including cell cycle, apoptosis, and differentiation. The relevance of these small molecules is even more evident in light of the emerging linkage between their expression and both prognosis and clinical outcome of many types of human cancers. This identifies microRNAs as potential therapeutic modifiers of cancer phenotypes. From this perspective, we overview here the miR-10b locus and its involvement in cancer, focusing on its role in the establishment (miR-10b*) and spreading (miR-10b) of breast cancer. We conclude that targeting the locus of microRNA 10b holds great potential for cancer treatment. PMID:23839045

  14. High-resolution mapping of the X-linked hypohidrotic ectodermal dysplasia (EDA) locus

    PubMed Central

    Zonana, J.; Jones, M.; Browne, D.; Litt, M.; Kramer, P.; Becker, H. W.; Brockdorff, N.; Rastan, S.; Davies, K. P.; Clarke, A.; Thomas, N. S. T.

    1992-01-01

    The X-linked hypohidrotic ectodermal dysplasia (EDA) locus has been previously localized to the subchromosomal region Xq11-q21.1. We have extended our previous linkage studies and analyzed linkage between the EDA locus and 10 marker loci, including five new loci, in 41 families. Four of the marker loci showed no recombination with the EDA locus, and six other loci were also linked to the EDA locus with recombination fractions of .009–.075. Multipoint analyses gave support to the placement of the PGK1P1 locus proximal to the EDA locus and the DXS453 and PGK1 loci distal to EDA. Further ordering of the loci could be inferred from a human/rodent somatic cell hybrid derived from an affected female with EDA and an X;9 translocation and from studies of an affected male with EDA and a submicroscopic deletion. Three of the proximal marker loci, which showed no recombination with the EDA locus, when used in combination, were informative in 92% of females. The closely linked flanking polymorphic loci DXS339 and DXS453 had heterozygosities of 72% and 76%, respectively, and when used jointly, they were doubly informative in 52% of females. The human DXS732 locus was defined by a conserved mouse probe pcos169E/4 (DXCrc169 locus) that cosegregates with the mouse tabby (Ta) locus, a potential homologue to the EDA locus. The absence of recombination between EDA and the DXS732 locus lends support to the hypothesis that the DXCrc169 locus in the mouse and the DXS732 locus in humans may contain candidate sequences for the Ta and EDA genes, respectively. PMID:1357963

  15. The immunoglobulin heavy chain locus in the platypus (Ornithorhynchus anatinus).

    PubMed

    Gambón-Deza, F; Sánchez-Espinel, C; Magadán-Mompó, S

    2009-08-01

    Immunoglobulins loci in mammals are well known to be organized within a translocon, however their origin remains unresolved. Four of the five classes of immunoglobulins described in humans and rodents (immunoglobulins M, G, E and A-IgM, IgG, IgE and IgA) were found in marsupials and monotremes (immunoglobulin D-IgD was not found) thus showing that the genomic structure of antibodies in mammals has remained constant since its origin. We have recently described the genomic organization of the immunoglobulin heavy chain locus in reptiles (IGHM, IGHD and IGHY). These data and the characterization of the IGH locus in platypus (Ornithorhynchus anatinus), allow us to elucidate the changes that took place in this genomic region during evolution from reptile to mammal. Thus, by using available genome data, we were able to detect that platypus IGH locus contains reptilian and mammalian genes. Besides having an IGHD that is very similar to the one in reptiles and an IGHY, they also present the mammal specific antibody genes IGHG and IGHE, in addition to IGHA. We also detected a pseudogene that originated by recombination between the IGHD and the IGHM (similar to the IGHD2 found in Eublepharis macularius). The analysis of the IGH locus in platypus shows that IGHY was duplicated, firstly by evolving into IGHE and then into IGHG. The IGHA of the platypus has a complex origin, and probably arose by a process of recombination between the IGHM and the IGHY. We detected about 44 VH genes (25 were already described), most of which comprise a single group. When we compared these VH genes with those described in Anolis carolinensis, we find that there is an evolutionary relationship between the VH genes of platypus and the reptilian Group III genes. These results suggest that a fast VH turnover took place in platypus and this gave rise to a family with a high VH gene number and the disappearance of the earlier VH families. PMID:19505725

  16. Analysis of the ABCA4 genomic locus in Stargardt disease.

    PubMed

    Zernant, Jana; Xie, Yajing Angela; Ayuso, Carmen; Riveiro-Alvarez, Rosa; Lopez-Martinez, Miguel-Angel; Simonelli, Francesca; Testa, Francesco; Gorin, Michael B; Strom, Samuel P; Bertelsen, Mette; Rosenberg, Thomas; Boone, Philip M; Yuan, Bo; Ayyagari, Radha; Nagy, Peter L; Tsang, Stephen H; Gouras, Peter; Collison, Frederick T; Lupski, James R; Fishman, Gerald A; Allikmets, Rando

    2014-12-20

    Autosomal recessive Stargardt disease (STGD1, MIM 248200) is caused by mutations in the ABCA4 gene. Complete sequencing of ABCA4 in STGD patients identifies compound heterozygous or homozygous disease-associated alleles in 65-70% of patients and only one mutation in 15-20% of patients. This study was designed to find the missing disease-causing ABCA4 variation by a combination of next-generation sequencing (NGS), array-Comparative Genome Hybridization (aCGH) screening, familial segregation and in silico analyses. The entire 140 kb ABCA4 genomic locus was sequenced in 114 STGD patients with one known ABCA4 exonic mutation revealing, on average, 200 intronic variants per sample. Filtering of these data resulted in 141 candidates for new mutations. Two variants were detected in four samples, two in three samples, and 20 variants in two samples, the remaining 117 new variants were detected only once. Multimodal analysis suggested 12 new likely pathogenic intronic ABCA4 variants, some of which were specific to (isolated) ethnic groups. No copy number variation (large deletions and insertions) was detected in any patient suggesting that it is a very rare event in the ABCA4 locus. Many variants were excluded since they were not conserved in non-human primates, were frequent in African populations and, therefore, represented ancestral, and not disease-associated, variants. The sequence variability in the ABCA4 locus is extensive and the non-coding sequences do not harbor frequent mutations in STGD patients of European-American descent. Defining disease-associated alleles in the ABCA4 locus requires exceptionally well characterized large cohorts and extensive analyses by a combination of various approaches. PMID:25082829

  17. A large duplication involving the IHH locus mimics acrocallosal syndrome

    PubMed Central

    Yuksel-Apak, Memnune; Bögershausen, Nina; Pawlik, Barbara; Li, Yun; Apak, Selcuk; Uyguner, Oya; Milz, Esther; Nürnberg, Gudrun; Karaman, Birsen; Gülgören, Ayan; Grzeschik, Karl-Heinz; Nürnberg, Peter; Kayserili, Hülya; Wollnik, Bernd

    2012-01-01

    Indian hedgehog (Ihh) signaling is a major determinant of various processes during embryonic development and has a pivotal role in embryonic skeletal development. A specific spatial and temporal expression of Ihh within the developing limb buds is essential for accurate digit outgrowth and correct digit number. Although missense mutations in IHH cause brachydactyly type A1, small tandem duplications involving the IHH locus have recently been described in patients with mild syndactyly and craniosynostosis. In contrast, a ∼600-kb deletion 5′ of IHH in the doublefoot mouse mutant (Dbf) leads to severe polydactyly without craniosynostosis, but with craniofacial dysmorphism. We now present a patient resembling acrocallosal syndrome (ACS) with extensive polysyndactyly of the hands and feet, craniofacial abnormalities including macrocephaly, agenesis of the corpus callosum, dysplastic and low-set ears, severe hypertelorism and profound psychomotor delay. Single-nucleotide polymorphism (SNP) array copy number analysis identified a ∼900-kb duplication of the IHH locus, which was confirmed by an independent quantitative method. A fetus from a second pregnancy of the mother by a different spouse showed similar craniofacial and limb malformations and the same duplication of the IHH-locus. We defined the exact breakpoints and showed that the duplications are identical tandem duplications in both sibs. No copy number changes were observed in the healthy mother. To our knowledge, this is the first report of a human phenotype similar to the Dbf mutant and strikingly overlapping with ACS that is caused by a copy number variation involving the IHH locus on chromosome 2q35. PMID:22234151

  18. Characterization of a Multipeptide Lantibiotic Locus in Streptococcus pneumoniae

    PubMed Central

    Maricic, Natalie; Anderson, Erica S.; Opipari, AnneMarie E.; Yu, Emily A.

    2016-01-01

    ABSTRACT Bacterial communities are established through a combination of cooperative and antagonistic interactions between the inhabitants. Competitive interactions often involve the production of antimicrobial substances, including bacteriocins, which are small antimicrobial peptides that target other community members. Despite the nearly ubiquitous presence of bacteriocin-encoding loci, inhibitory activity has been attributed to only a small fraction of gene clusters. In this study, we characterized a novel locus (the pld locus) in the pathogen Streptococcus pneumoniae that drives the production of a bacteriocin called pneumolancidin, which has broad antimicrobial activity. The locus encodes an unusual tandem array of four inhibitory peptides, three of which are absolutely required for antibacterial activity. The three peptide sequences are similar but appear to play distinct roles in regulation and inhibition. A modification enzyme typically found in loci encoding a class of highly modified bacteriocins called lantibiotics was required for inhibitory activity. The production of pneumolancidin is controlled by a two-component regulatory system that is activated by the accumulation of modified peptides. The locus is located on a mobile element that has been found in many pneumococcal lineages, although not all elements carry the pld genes. Intriguingly, a minimal region containing only the genes required for pneumolancidin immunity was found in several Streptococcus mitis strains. The pneumolancidin-producing strain can inhibit nearly all pneumococci tested to date and provided a competitive advantage in vivo. These peptides not only represent a unique strategy for bacterial competition but also are an important resource to guide the development of new antimicrobials. PMID:26814178

  19. Excess polymorphism at the Adh locus in Drosophila melanogaster.

    PubMed

    Kreitman, M E; Aguadé, M

    1986-09-01

    The evolutionary history of a region of DNA encompassing the Adh locus is studied by comparing patterns of variation in Drosophila melanogaster and its sibling species, D. simulans. An unexpectedly high level of silent polymorphism in the Adh coding region relative to the 5' and 3' flanking regions in D. melanogaster is revealed by a populational survey of restriction polymorphism using a four-cutter filter hybridization technique as well as by direct sequence comparisons. In both of these studies, a region of the Adh gene encompassing the three coding exons exhibits a frequency of polymorphism equal to that of a 4-kb 5' flanking region. In contrast, an interspecific sequence comparison shows a two-fold higher level of divergence in the 5' flanking sequence compared to the structural locus. Analysis of the patterns of variation suggest an excess of polymorphism within the D. melanogaster Adh locus, rather than lack of polymorphism in the 5' flanking region. An approach is outlined for testing neutral theory predictions about patterns of variation within and between species. This approach indicates that the observed patterns of variation are incompatible with an infinite site neutral model. PMID:3021568

  20. Fine mapping the TAGAP risk locus in rheumatoid arthritis.

    PubMed

    Chen, R; Stahl, E A; Kurreeman, F A S; Gregersen, P K; Siminovitch, K A; Worthington, J; Padyukov, L; Raychaudhuri, S; Plenge, R M

    2011-06-01

    A common allele at the TAGAP gene locus demonstrates a suggestive, but not conclusive association with risk of rheumatoid arthritis (RA). To fine map the locus, we conducted comprehensive imputation of CEU HapMap single-nucleotide polymorphisms (SNPs) in a genome-wide association study (GWAS) of 5,500 RA cases and 22,621 controls (all of European ancestry). After controlling for population stratification with principal components analysis, the strongest signal of association was to an imputed SNP, rs212389 (P=3.9 × 10(-8), odds ratio=0.87). This SNP remained highly significant upon conditioning on the previous RA risk variant (rs394581, P=2.2 × 10(-5)) or on a SNP previously associated with celiac disease and type I diabetes (rs1738074, P=1.7 × 10(-4)). Our study has refined the TAGAP signal of association to a single haplotype in RA, and in doing so provides conclusive statistical evidence that the TAGAP locus is associated with RA risk. Our study also underscores the utility of comprehensive imputation in large GWAS data sets to fine map disease risk alleles. PMID:21390051

  1. Culture, serotonin receptor polymorphism and locus of attention

    PubMed Central

    Sherman, David K.; Taylor, Shelley E.; Sasaki, Joni Y.; Chu, Thai Q.; Ryu, Chorong; Suh, Eunkook M.; Xu, Jun

    2010-01-01

    The present research examined the interaction between genes and culture as potential determinants of individuals’ locus of attention. As the serotonin (5-HT) system has been associated with attentional focus and the ability to adapt to changes in reinforcement, we examined the serotonin 1A receptor polymorphism (5-HTR1A). Koreans and European Americans were genotyped and reported their chronic locus of attention. There was a significant interaction between 5-HTR1A genotype and culture in the locus of attention. Koreans reported attending to the field more than European Americans, and this cultural difference was moderated by 5-HTR1A. There was a linear pattern such that those homozygous for the G allele, which is associated with reduced ability to adapt to changes in reinforcement, more strongly endorsed the culturally reinforced mode of thinking than those homozygous for the C allele, with those heterozygous in the middle. Our findings suggest that the same genetic predisposition can result in divergent psychological outcomes, depending on an individual’s cultural context. PMID:19736291

  2. Genomic characterization of the Atlantic cod sex-locus.

    PubMed

    Star, Bastiaan; Tørresen, Ole K; Nederbragt, Alexander J; Jakobsen, Kjetill S; Pampoulie, Christophe; Jentoft, Sissel

    2016-01-01

    A variety of sex determination mechanisms can be observed in evolutionary divergent teleosts. Sex determination is genetic in Atlantic cod (Gadus morhua), however the genomic location or size of its sex-locus is unknown. Here, we characterize the sex-locus of Atlantic cod using whole genome sequence (WGS) data of 227 wild-caught specimens. Analyzing more than 55 million polymorphic loci, we identify 166 loci that are associated with sex. These loci are located in six distinct regions on five different linkage groups (LG) in the genome. The largest of these regions, an approximately 55 Kb region on LG11, contains the majority of genotypes that segregate closely according to a XX-XY system. Genotypes in this region can be used genetically determine sex, whereas those in the other regions are inconsistently sex-linked. The identified region on LG11 and its surrounding genes have no clear sequence homology with genes or regulatory elements associated with sex-determination or differentiation in other species. The functionality of this sex-locus therefore remains unknown. The WGS strategy used here proved adequate for detecting the small regions associated with sex in this species. Our results highlight the evolutionary flexibility in genomic architecture underlying teleost sex-determination and allow practical applications to genetically sex Atlantic cod. PMID:27499266

  3. Genetic analysis of the claret locus of Drosophila melanogaster

    SciTech Connect

    Sequeira, W.; Nelson, C.R.; Szauter, P. )

    1989-11-01

    The claret (ca) locus of Drosophila melanogaster comprises two separately mutable domains, one responsible for eye color and one responsible for proper disjunction of chromosomes in meiosis and early cleavage divisions. Previously isolated alleles are of three types: (1) alleles of the claret (ca) type that affect eye color only, (2) alleles of the claret-nondisjunctional (ca{sup nd}) type that affect eye color and chromosome behavior, and (3) a meiotic mutation, non-claret disjunctional (ncd), that affects chromosome behavior only. In order to investigate the genetic structure of the claret locus, the authors have isolated 19 radiation-induced alleles of claret on the basis of the eye color phenotype. Two of these 19 new alleles are of the ca{sup nd} type, while 17 are of the ca type, demonstrating that the two domains do not often act as a single target for mutagenesis. This suggests that the two separately mutable functions are likely to be encoded by separate or overlapping genes rather than by a single gene. One of the new alleles of the ca{sup nd} type is a chromosome rearrangement with a breakpoint at the position of the claret locus. If this breakpoint is the cause of the mutant phenotype and there are no other mutations associated with the rearrangement, the two functions must be encoded by overlapping genes.

  4. Genomic characterization of the Atlantic cod sex-locus

    PubMed Central

    Star, Bastiaan; Tørresen, Ole K.; Nederbragt, Alexander J.; Jakobsen, Kjetill S.; Pampoulie, Christophe; Jentoft, Sissel

    2016-01-01

    A variety of sex determination mechanisms can be observed in evolutionary divergent teleosts. Sex determination is genetic in Atlantic cod (Gadus morhua), however the genomic location or size of its sex-locus is unknown. Here, we characterize the sex-locus of Atlantic cod using whole genome sequence (WGS) data of 227 wild-caught specimens. Analyzing more than 55 million polymorphic loci, we identify 166 loci that are associated with sex. These loci are located in six distinct regions on five different linkage groups (LG) in the genome. The largest of these regions, an approximately 55 Kb region on LG11, contains the majority of genotypes that segregate closely according to a XX-XY system. Genotypes in this region can be used genetically determine sex, whereas those in the other regions are inconsistently sex-linked. The identified region on LG11 and its surrounding genes have no clear sequence homology with genes or regulatory elements associated with sex-determination or differentiation in other species. The functionality of this sex-locus therefore remains unknown. The WGS strategy used here proved adequate for detecting the small regions associated with sex in this species. Our results highlight the evolutionary flexibility in genomic architecture underlying teleost sex-determination and allow practical applications to genetically sex Atlantic cod. PMID:27499266

  5. Restoration of Bioactive Lantibiotic Suicin from a Remnant lan Locus of Pathogenic Streptococcus suis Serotype 2

    PubMed Central

    Wang, Jian; Gao, Yong; Teng, Kunling; Zhang, Jie; Sun, Shutao

    2014-01-01

    Lantibiotics are ribosomally synthesized, posttranslationally modified antimicrobial peptides. Their biosynthesis genes are usually organized in gene clusters, which are mainly found in Gram-positive bacteria, including pathogenic streptococci. Three highly virulent Streptococcus suis serotype 2 strains (98HAH33, 05ZYH33, and SC84) have been shown to contain an 89K pathogenicity island. Here, on these islands, we unveiled and reannotated a putative lantibiotic locus designated sui which contains a virulence-associated two-component regulator, suiK-suiR. In silico analysis revealed that the putative lantibiotic modification gene suiM was interrupted by a 7.9-kb integron and that other biosynthesis-related genes contained various frameshift mutations. By reconstituting the intact suiM in Escherichia coli together with a semi-in vitro biosynthesis system, a putative lantibiotic named suicin was produced with bactericidal activities against a variety of Gram-positive strains, including pathogenic streptococci and vancomycin-resistant enterococci. Ring topology dissection indicated that the 34-amino-acid lantibiotic contained two methyllanthionine residues and one disulfide bridge, which render suicin in an N-terminal linear and C-terminal globular shape. To confirm the function of suiK-suiR, SuiR was overexpressed and purified. In vitro analysis showed that SuiR could specifically bind to the suiA gene promoter. Its coexpression with suiK could activate suiA gene promoter in Lactococcus lactis NZ9000. Conclusively, we obtained a novel lantibiotic suicin by restoring its production from the remnant sui locus and demonstrated that virulence-associated SuiK-SuiR regulates its production. PMID:24271178

  6. Fine Mapping of the Barley Chromosome 6H Net Form Net Blotch Susceptibility Locus

    PubMed Central

    Richards, Jonathan; Chao, Shiaoman; Friesen, Timothy; Brueggeman, Robert

    2016-01-01

    Net form net blotch, caused by the necrotrophic fungal pathogen Pyrenophora teres f. teres, is a destructive foliar disease of barley with the potential to cause significant yield loss in major production regions throughout the world. The complexity of the host–parasite genetic interactions in this pathosystem hinders the deployment of effective resistance in barley cultivars, warranting a deeper understanding of the interactions. Here, we report on the high-resolution mapping of the dominant susceptibility locus near the centromere of chromosome 6H in the barley cultivars Rika and Kombar, which are putatively targeted by necrotrophic effectors from P. teres f. teres isolates 6A and 15A, respectively. Utilization of progeny isolates derived from a cross of P. teres f. teres isolates 6A × 15A harboring single major virulence loci (VK1, VK2, and VR2) allowed for the Mendelization of single inverse gene-for-gene interactions in a high-resolution population consisting of 2976 Rika × Kombar recombinant gametes. Brachypodium distachyon synteny was exploited to develop and saturate the susceptibility region with markers, delimiting it to ∼0.24 cM and a partial physical map was constructed. This genetic and physical characterization further resolved the dominant susceptibility locus, designated Spt1 (susceptibility to P. teres f. teres). The high-resolution mapping and cosegregation of the Spt1.R and Spt1.K gene/s indicates tightly linked genes in repulsion or alleles possibly targeted by different necrotrophic effectors. Newly developed barley genomic resources greatly enhance the efficiency of positional cloning efforts in barley, as demonstrated by the Spt1 fine mapping and physical contig identification reported here. PMID:27172206

  7. Fine Mapping of the Barley Chromosome 6H Net Form Net Blotch Susceptibility Locus.

    PubMed

    Richards, Jonathan; Chao, Shiaoman; Friesen, Timothy; Brueggeman, Robert

    2016-01-01

    Net form net blotch, caused by the necrotrophic fungal pathogen Pyrenophora teres f. teres, is a destructive foliar disease of barley with the potential to cause significant yield loss in major production regions throughout the world. The complexity of the host-parasite genetic interactions in this pathosystem hinders the deployment of effective resistance in barley cultivars, warranting a deeper understanding of the interactions. Here, we report on the high-resolution mapping of the dominant susceptibility locus near the centromere of chromosome 6H in the barley cultivars Rika and Kombar, which are putatively targeted by necrotrophic effectors from P. teres f. teres isolates 6A and 15A, respectively. Utilization of progeny isolates derived from a cross of P. teres f. teres isolates 6A × 15A harboring single major virulence loci (VK1, VK2, and VR2) allowed for the Mendelization of single inverse gene-for-gene interactions in a high-resolution population consisting of 2976 Rika × Kombar recombinant gametes. Brachypodium distachyon synteny was exploited to develop and saturate the susceptibility region with markers, delimiting it to ∼0.24 cM and a partial physical map was constructed. This genetic and physical characterization further resolved the dominant susceptibility locus, designated Spt1 (susceptibility to P. teres f. teres). The high-resolution mapping and cosegregation of the Spt1.R and Spt1.K gene/s indicates tightly linked genes in repulsion or alleles possibly targeted by different necrotrophic effectors. Newly developed barley genomic resources greatly enhance the efficiency of positional cloning efforts in barley, as demonstrated by the Spt1 fine mapping and physical contig identification reported here. PMID:27172206

  8. Visco-resistive plasmoid instability

    NASA Astrophysics Data System (ADS)

    Comisso, Luca; Grasso, Daniela

    2016-03-01

    The plasmoid instability in visco-resistive current sheets is analyzed in both the linear and nonlinear regimes. The linear growth rate and the wavenumber are found to scale as S1 /4(1+Pm ) -5 /8 and S3 /8(1+Pm ) -3 /16 with respect to the Lundquist number S and the magnetic Prandtl number Pm. Furthermore, the linear layer width is shown to scale as S-1 /8(1+Pm ) 1 /16 . The growth of the plasmoids slows down from an exponential growth to an algebraic growth when they enter into the nonlinear regime. In particular, the time-scale of the nonlinear growth of the plasmoids is found to be τNL˜S-3 /16(1+Pm) 19 /32τA,L . The nonlinear growth of the plasmoids is radically different from the linear one, and it is shown to be essential to understand the global current sheet disruption. It is also discussed how the plasmoid instability enables fast magnetic reconnection in visco-resistive plasmas. In particular, it is shown that the recursive plasmoid formation can trigger a collisionless reconnection regime if S ≳Lc s(ɛclk) -1(1+Pm) 1 /2 , where Lcs is the half-length of the global current sheet and lk is the relevant kinetic length scale. On the other hand, if the current sheet remains in the collisional regime, the global (time-averaged) reconnection rate is shown to be ≈ɛcvA ,uBu(1+Pm) -1 /2 , where ɛc is the critical inverse aspect ratio of the current sheet, while vA,u and Bu are the Alfvén speed and the magnetic field upstream of the global reconnection layer.

  9. Population structure and its effect on haplotype diversity and linkage disequilibrium surrounding the xa5 locus of rice (Oryza sativa L.).

    PubMed Central

    Garris, Amanda J; McCouch, Susan R; Kresovich, Stephen

    2003-01-01

    To assess the usefulness of linkage disequilibrium mapping in an autogamous, domesticated species, we have characterized linkage disequilibrium in the candidate region for xa5, a recessive gene conferring race-specific resistance to bacterial blight in rice. This trait and locus have good mapping information, a tractable phenotype, and available sequence data, but no cloned gene. We sampled 13 short segments from the 70-kb candidate region in 114 accessions of Oryza sativa. Five additional segments were sequenced from the adjacent 45-kb region in resistant accessions to estimate the distance at which linkage disequilibrium decays. The data show significant linkage disequilibrium between sites 100 kb apart. The presence of the xa5 resistant reaction in two ecotypes and in accessions with different haplotypes in the candidate region may indicate multiple origins or genetic heterogeneity for resistance. In addition, genetic differentiation between ecotypes emphasizes the need for controlling for population structure in the design of linkage disequilibrium studies in rice. PMID:14573486

  10. The Cross-Linking Agent Hexamethylphosphoramide Predominantly Induces Intra-Locus and Multi-Locus Deletions in Postmeiotic Germ Cells of Drosophila

    PubMed Central

    Aguirrezabalaga, I.; Nivard, MJM.; Comendador, M. A.; Vogel, E. W.

    1995-01-01

    The nature of DNA sequence changes induced by the cross-linking agent hexamethylphosphoramide (HMPA) within and in the vicinity of the vermilion locus of Drosophila melanogaster that produce a vermilion mutant phenotype was analyzed after exposure of postmeiotic male germ cells. Mutagenized males were mated to either females wild-type (exr(+)) for nucleotide excision repair (NER) or to females having a deficiency (exr(-)) for NER. Rearrangements, mostly deletions, represented by far the most frequent type of mutational events induced by HMPA that are detected as vermilion mutations. In the exr(+) group, all but one (a double substitution) of 21 mutants characterized were large sequence changes: we found 5 intra-locus deletions, 3 intra-locus deletions associated with insertions and 12 multi-locus deletions. When taken together, deletions and deletion/insertion mutations represent 96% of the HMPA-induced DNA modifications obtained under proficient repair conditions. Of the 10 mutants obtained from crosses with exr(-) females, 6 intra-locus and 2 multi-locus deletions were found, as opposed to just 1 point mutation and 1 double substitution. The ``hypomutability effect'' observed with exr(-) genotypes in relation to the wild type seems to be caused by a decrease in the frequency of multi-locus deletions in the former group. The results suggest that the NER system is involved in the generation of multi-locus deletions, whereas intra-locus deletions appear to be formed through a postreplication slipped-misrepair pathway. It is concluded that an eukaryotic in vivo system with no limitations for the recovery of multi-locus deletions, such as vermilion, should be used for the analysis of DNA damage induced by cross-linking agents. PMID:7713422

  11. Locus of control, television viewing, and eating disorder symptomatology in young females.

    PubMed

    Fouts, Gregory; Vaughan, Kimberley

    2002-06-01

    The purpose of this study was to assess the effects of locus of control and television watching (number of hours of television watched per week) on eating disorder symptomatology in girls between the ages 10-17 years. A 2 x 2 factorial design was employed in which girls were identified either as (a) being higher or lower viewers of television, and (b) having either an external or internal locus of control. Girls with an external locus of control had significantly greater eating disorder symptomatology than those with an internal locus of control. For girls watching higher amounts of television, those having an external locus of control had significantly greater eating disorder symptomatology than those having an internal locus of control. PMID:12128041

  12. Bundle-forming pilus locus of Aeromonas veronii bv. Sobria.

    PubMed

    Hadi, Nahal; Yang, Qin; Barnett, Timothy C; Tabei, S Mohammed B; Kirov, Sylvia M; Shaw, Jonathan G

    2012-04-01

    Little is known about the colonization mechanisms of Aeromonas spp. Previous work has suggested that the type IV bundle-forming pilus (Bfp) is an aeromonad intestinal colonization factor. This study provides the first genetic characterization of this structure. To define the role of Bfp in Aeromonas veronii bv. Sobria adherence, a 22-kb locus encoding the bundle-forming pilus was isolated; this contained 17 pilus-related genes similar to the mannose-sensitive hemagglutinin (MSHA) of Vibrio cholerae. Reverse transcriptase PCR (RT-PCR) demonstrated that the locus had two major transcriptional units, mshI to mshF and mshB to mshQ. Transcriptional fusion experiments demonstrated the presence of two strong promoters upstream of mshI and mshB. The locus encoded four putative prepilin proteins, one of which (MshA) corresponded to the N-terminal sequence of the previously isolated major pilin protein. All the pilin genes were inactivated, mutation of each minor or major pilin gene greatly reduced the bacterium's ability to adhere and form biofilms, and complementation of each mutant in trans rescued this phenotype. Mutation of the major pilin MshA and MshB, a minor pilin, resulted in their loss. The position of the mshH gene is conserved within a number of bacteria, and we have shown it is not transcriptionally linked to the other msh genes; moreover, its mutation did not have a dramatic effect on either adhesion or biofilm formation. We conclude that the bundle-forming pilus is required for A. veronii bv. Sobria adherence and biofilm formation; furthermore, both the major and minor pilin proteins are essential for this process. PMID:22311923

  13. Locus minimization in breed prediction using artificial neural network approach.

    PubMed

    Iquebal, M A; Ansari, M S; Sarika; Dixit, S P; Verma, N K; Aggarwal, R A K; Jayakumar, S; Rai, A; Kumar, D

    2014-12-01

    Molecular markers, viz. microsatellites and single nucleotide polymorphisms, have revolutionized breed identification through the use of small samples of biological tissue or germplasm, such as blood, carcass samples, embryos, ova and semen, that show no evident phenotype. Classical tools of molecular data analysis for breed identification have limitations, such as the unavailability of referral breed data, causing increased cost of collection each time, compromised computational accuracy and complexity of the methodology used. We report here the successful use of an artificial neural network (ANN) in background to decrease the cost of genotyping by locus minimization. The webserver is freely accessible (http://nabg.iasri.res.in/bisgoat) to the research community. We demonstrate that the machine learning (ANN) approach for breed identification is capable of multifold advantages such as locus minimization, leading to a drastic reduction in cost, and web availability of reference breed data, alleviating the need for repeated genotyping each time one investigates the identity of an unknown breed. To develop this model web implementation based on ANN, we used 51,850 samples of allelic data of microsatellite-marker-based DNA fingerprinting on 25 loci covering 22 registered goat breeds of India for training. Minimizing loci to up to nine loci through the use of a multilayer perceptron model, we achieved 96.63% training accuracy. This server can be an indispensable tool for identification of existing breeds and new synthetic commercial breeds, leading to protection of intellectual property in case of sovereignty and bio-piracy disputes. This server can be widely used as a model for cost reduction by locus minimization for various other flora and fauna in terms of variety, breed and/or line identification, especially in conservation and improvement programs. PMID:25183434

  14. Genetic Locus for Streptolysin S Production by Group A Streptococcus

    PubMed Central

    Nizet, Victor; Beall, Bernard; Bast, Darrin J.; Datta, Vivekananda; Kilburn, Laurie; Low, Donald E.; De Azavedo, Joyce C. S.

    2000-01-01

    Group A streptococcus (GAS) is an important human pathogen that causes pharyngitis and invasive infections, including necrotizing fasciitis. Streptolysin S (SLS) is the cytolytic factor that creates the zone of beta-hemolysis surrounding GAS colonies grown on blood agar. We recently reported the discovery of a potential genetic determinant involved in SLS production, sagA, encoding a small peptide of 53 amino acids (S. D. Betschel, S. M. Borgia, N. L. Barg, D. E. Low, and J. C. De Azavedo, Infect. Immun. 66:1671–1679, 1998). Using transposon mutagenesis, chromosomal walking steps, and data from the GAS genome sequencing project (www.genome.ou.edu/strep.html), we have now identified a contiguous nine-gene locus (sagA to sagI) involved in SLS production. The sag locus is conserved among GAS strains regardless of M protein type. Targeted plasmid integrational mutagenesis of each gene in the sag operon resulted in an SLS-negative phenotype. Targeted integrations (i) upstream of the sagA promoter and (ii) downstream of a terminator sequence after sagI did not affect SLS production, establishing the functional boundaries of the operon. A rho-independent terminator sequence between sagA and sagB appears to regulate the amount of sagA transcript produced versus transcript for the entire operon. Reintroduction of the nine-gene sag locus on a plasmid vector restored SLS activity to the nonhemolytic sagA knockout mutant. Finally, heterologous expression of the intact sag operon conferred the SLS beta-hemolytic phenotype to the nonhemolytic Lactococcus lactis. We conclude that gene products of the GAS sag operon are both necessary and sufficient for SLS production. Sequence homologies of sag operon gene products suggest that SLS is related to the bacteriocin family of microbial toxins. PMID:10858242

  15. Bundle-Forming Pilus Locus of Aeromonas veronii bv. Sobria

    PubMed Central

    Hadi, Nahal; Yang, Qin; Barnett, Timothy C.; Tabei, S. Mohammed B.; Kirov, Sylvia M.

    2012-01-01

    Little is known about the colonization mechanisms of Aeromonas spp. Previous work has suggested that the type IV bundle-forming pilus (Bfp) is an aeromonad intestinal colonization factor. This study provides the first genetic characterization of this structure. To define the role of Bfp in Aeromonas veronii bv. Sobria adherence, a 22-kb locus encoding the bundle-forming pilus was isolated; this contained 17 pilus-related genes similar to the mannose-sensitive hemagglutinin (MSHA) of Vibrio cholerae. Reverse transcriptase PCR (RT-PCR) demonstrated that the locus had two major transcriptional units, mshI to mshF and mshB to mshQ. Transcriptional fusion experiments demonstrated the presence of two strong promoters upstream of mshI and mshB. The locus encoded four putative prepilin proteins, one of which (MshA) corresponded to the N-terminal sequence of the previously isolated major pilin protein. All the pilin genes were inactivated, mutation of each minor or major pilin gene greatly reduced the bacterium's ability to adhere and form biofilms, and complementation of each mutant in trans rescued this phenotype. Mutation of the major pilin MshA and MshB, a minor pilin, resulted in their loss. The position of the mshH gene is conserved within a number of bacteria, and we have shown it is not transcriptionally linked to the other msh genes; moreover, its mutation did not have a dramatic effect on either adhesion or biofilm formation. We conclude that the bundle-forming pilus is required for A. veronii bv. Sobria adherence and biofilm formation; furthermore, both the major and minor pilin proteins are essential for this process. PMID:22311923

  16. Developmental expression of the white locus of Drosophila melanogaster

    PubMed Central

    Fjose, A.; Polito, L. C.; Weber, U.; Gehring, W. J.

    1984-01-01

    We have isolated several cDNA clones of the white locus which are derived from embryonic and pupal transcripts of Drosophila melanogaster. The cDNA sequences map within ˜7.5 kb (coordinates −3.0 to +4.6) of the genomic DNA and correspond mainly to sequences within the distal region of the gene (coordinates −0.2 to −3.0). A major RNA species of 2.6 kb was detected on Northerns of poly(A)+ RNA isolated from all developmental stages. The total accumulation of this transcript peaks in the mature third instar larva to a level of 0.003% which is about ten times higher than that observed in embryos. The spatial distribution of white locus transcripts was determined by in situ hybridization to tissue sections. In embryos, hybridization signals are restricted to the cells of the developing Malpighian tubules and the signal strength corresponds with ˜50 transcripts per cell. Before the termination of the third instar stage, hybridization signals are also detected at a comparable level in the eye antennal disks. At the same stage, a third site of labeling is observed over a small cluster of cells which seems to be associated with the larval photoreceptor organs. Thus, white locus expression is largely restricted to tissues which are known to be involved in the biosynthesis of eye pigments and these different cell types act in a temporally autonomous manner with respect to the induction of the white gene during development. ImagesFig. 1.Fig. 2.Fig. 3.Fig. 4.Fig. 5. PMID:16453550

  17. Genome-wide association study for type 2 diabetes in Indians identifies a new susceptibility locus at 2q21.

    PubMed

    Tabassum, Rubina; Chauhan, Ganesh; Dwivedi, Om Prakash; Mahajan, Anubha; Jaiswal, Alok; Kaur, Ismeet; Bandesh, Khushdeep; Singh, Tejbir; Mathai, Benan John; Pandey, Yogesh; Chidambaram, Manickam; Sharma, Amitabh; Chavali, Sreenivas; Sengupta, Shantanu; Ramakrishnan, Lakshmi; Venkatesh, Pradeep; Aggarwal, Sanjay K; Ghosh, Saurabh; Prabhakaran, Dorairaj; Srinath, Reddy K; Saxena, Madhukar; Banerjee, Monisha; Mathur, Sandeep; Bhansali, Anil; Shah, Viral N; Madhu, Sri Venkata; Marwaha, Raman K; Basu, Analabha; Scaria, Vinod; McCarthy, Mark I; Venkatesan, Radha; Mohan, Viswanathan; Tandon, Nikhil; Bharadwaj, Dwaipayan

    2013-03-01

    Indians undergoing socioeconomic and lifestyle transitions will be maximally affected by epidemic of type 2 diabetes (T2D). We conducted a two-stage genome-wide association study of T2D in 12,535 Indians, a less explored but high-risk group. We identified a new type 2 diabetes-associated locus at 2q21, with the lead signal being rs6723108 (odds ratio 1.31; P = 3.32 × 10⁻⁹). Imputation analysis refined the signal to rs998451 (odds ratio 1.56; P = 6.3 × 10⁻¹²) within TMEM163 that encodes a probable vesicular transporter in nerve terminals. TMEM163 variants also showed association with decreased fasting plasma insulin and homeostatic model assessment of insulin resistance, indicating a plausible effect through impaired insulin secretion. The 2q21 region also harbors RAB3GAP1 and ACMSD; those are involved in neurologic disorders. Forty-nine of 56 previously reported signals showed consistency in direction with similar effect sizes in Indians and previous studies, and 25 of them were also associated (P < 0.05). Known loci and the newly identified 2q21 locus altogether explained 7.65% variance in the risk of T2D in Indians. Our study suggests that common susceptibility variants for T2D are largely the same across populations, but also reveals a population-specific locus and provides further insights into genetic architecture and etiology of T2D. PMID:23209189

  18. Evidence for a fourth locus in Usher syndrome type I.

    PubMed Central

    Gerber, S; Larget-Piet, D; Rozet, J M; Bonneau, D; Mathieu, M; Der Kaloustian, V; Munnich, A; Kaplan, J

    1996-01-01

    Usher syndrome type I (US1) is an autosomal recessive condition in which three different genes have been already localised (USH1A, USH1B, and USH1C on chromosomes 14q32, 11q13, and 11p15 respectively). The genetic heterogeneity of US1 has been confirmed in a previous study by linkage analysis of 20 French pedigrees. Here, we report the genetic exclusion of the three previously reported loci in two large multiplex families of Moroccan and Pakistani origin, suggesting the existence of at least a fourth locus in Usher syndrome type I. PMID:8825055

  19. Platinum coat color locus in the deer mouse.

    PubMed

    Dodson, K M; Dawson, W D; Van Ooteghem, S O; Cushing, B S; Haigh, G R

    1987-01-01

    Platinum coat color in the deer mouse, Peromyscus maniculatus, is an autosomal recessive trait marking a locus, pt, distinct from silver (si), albino (c), blonde (bl), brown (b), and agouti (a). Platinum deer mice are conspicuously pale, with light ears and tail stripe. The pewter trait is allelic with and phenotypically identical to platinum, and represents an independent recurrence of this mutant. The rate of recoveries of coat color mutations from wild deer mice is consistent with available data for recurring mutation rates balanced by strong selection against the recessive phenotype. PMID:3611714

  20. Pressure sore survey. Part 3: Locus of control.

    PubMed

    Maylor, M; Torrance, C

    1999-03-01

    This is the third in a three-part article which investigates the prevalence, knowledge and attitudes to pressure sores in one NHS trust. This study describes the methodology used in choosing and developing attitude scales to explore whether there are any relationships between the locus of control and pressure sore prevention. Factors to do with attitude and the value associated with pressure sore prevention have a central role. Attitudes and beliefs affect what we do and may contribute to pressure sore development. PMID:10362985

  1. Registration of near-isogenic winter wheat germplasm contrasting in Fhb1 for fusarium head blight resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Chinese wheat Ning7840 (Triticum aestivum L.) contains Fhb1, a major quantitative trait locus (QTL) for Fusarium head blight (FHB) resistance, and has been widely used as a resistant parent in breeding programs worldwide, but due to its poor adaptation in the US, its progenies usually exhibit re...

  2. A major quantitative trait locus is associated with Fusarium Wilt Race 1 resistance in watermelon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium wilt is a major disease of watermelon caused by the soil-borne fungus Fusarium oxysporum Schlechtend.:Fr. f. sp. niveum (E.F. Sm.) W.C. Snyder & H.N. Hans (Fon). A genetic population of 186 F3 families (24 plants in each family) exhibited continuous segregation for Fon race 1 response. Geno...

  3. Preserving rice quality: fine mapping and introgressing a fissure resistance locus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice (Oryza sativa L.) kernel fissuring is a major concern of both rice producers and millers. Fissures are small cracks in the rice kernels that increase the percentage of breakage among the kernels when they are transported and milled, which decreases the value of processed rice. This study employ...

  4. External locus of control contributes to racial disparities in memory and reasoning training gains in ACTIVE.

    PubMed

    Zahodne, Laura B; Meyer, Oanh L; Choi, Eunhee; Thomas, Michael L; Willis, Sherry L; Marsiske, Michael; Gross, Alden L; Rebok, George W; Parisi, Jeanine M

    2015-09-01

    Racial disparities in cognitive outcomes may be partly explained by differences in locus of control. African Americans report more external locus of control than non-Hispanic Whites, and external locus of control is associated with poorer health and cognition. The aims of this study were to compare cognitive training gains between African American and non-Hispanic White participants in the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study and determine whether racial differences in training gains are mediated by locus of control. The sample comprised 2,062 (26% African American) adults aged 65 and older who participated in memory, reasoning, or speed training. Latent growth curve models evaluated predictors of 10-year cognitive trajectories separately by training group. Multiple group modeling examined associations between training gains and locus of control across racial groups. Compared to non-Hispanic Whites, African Americans evidenced less improvement in memory and reasoning performance after training. These effects were partially mediated by locus of control, controlling for age, sex, education, health, depression, testing site, and initial cognitive ability. African Americans reported more external locus of control, which was associated with smaller training gains. External locus of control also had a stronger negative association with reasoning training gain for African Americans than for Whites. No racial difference in training gain was identified for speed training. Future intervention research with African Americans should test whether explicitly targeting external locus of control leads to greater cognitive improvement following cognitive training. PMID:26237116

  5. External locus of control contributes to racial disparities in memory and reasoning training gains in ACTIVE

    PubMed Central

    Zahodne, Laura B.; Meyer, Oanh L.; Choi, Eunhee; Thomas, Michael L.; Willis, Sherry L.; Marsiske, Michael; Gross, Alden L.; Rebok, George W.; Parisi, Jeanine M.

    2015-01-01

    Racial disparities in cognitive outcomes may be partly explained by differences in locus of control. African Americans report more external locus of control than non-Hispanic Whites, and external locus of control is associated with poorer health and cognition. The aims of this study were to compare cognitive training gains between African American and non-Hispanic White participants in the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study and determine whether racial differences in training gains are mediated by locus of control. The sample comprised 2,062 (26% African American) adults aged 65 and older who participated in memory, reasoning, or speed training. Latent growth curve models evaluated predictors of 10-year cognitive trajectories separately by training group. Multiple group modeling examined associations between training gains and locus of control across racial groups. Compared to non-Hispanic Whites, African Americans evidenced less improvement in memory and reasoning performance after training. These effects were partially mediated by locus of control, controlling for age, sex, education, health, depression, testing site, and initial cognitive ability. African Americans reported more external locus of control, which was associated with smaller training gains. External locus of control also had a stronger negative association with reasoning training gain for African Americans than for Whites. No racial difference in training gain was identified for speed training. Future intervention research with African Americans should test whether explicitly targeting external locus of control leads to greater cognitive improvement following cognitive training. PMID:26237116

  6. Effect of induced elation and depression on internal-external locus of control.

    PubMed

    Natale, M

    1978-11-01

    This study tested the notion that depression is associated with external locus of control and elation is related to internal locus of control. Temporary mood states (depression, elation, neutral) were produced by means of Velten's auto-suggestion technique. Fifteen female undergraduates were assigned to each mood condition, and locus of control scores were obtained both before and after the mood induction procedure. Pre-post changes were as predicted: elation caused an increased sense of internality, and depression caused an increased sense of externality. Neutral mood induction did not alter locus of control. PMID:722649

  7. Antibiotic Resistance

    MedlinePlus

    ... For Consumers Consumer Information by Audience For Women Antibiotic Resistance Share Tweet Linkedin Pin it More sharing options ... these products really help. To Learn More about Antibiotic Resistance Get Smart About Antibiotics (Video) Fact Sheets and ...

  8. Identification of Soybean Proteins and Genes Differentially Regulated in Near Isogenic Lines Differing in Resistance to Aphid Infestation.

    PubMed

    Brechenmacher, Laurent; Nguyen, Tran Hong Nha; Zhang, Ning; Jun, Tae-Hwan; Xu, Dong; Mian, M A Rouf; Stacey, Gary

    2015-10-01

    Soybean aphid is an important pest causing significant yield losses. The Rag2 locus confers resistance to soybean aphid biotypes 1 and 2. Transcriptomic and proteomic analyses were done over a 48 h period after aphid infestation using near isogenic lines (NILs) differing at the Rag2 locus. Comparing the Rag2 and/or rag2 lines identified 3445 proteins, of which 396 were differentially regulated between the two lines, including proteins involved in cell wall metabolism, carbohydrate metabolism, and stress response. RNA-seq transcriptomic analysis identified 2361 genes significantly regulated between the resistant and susceptible lines. Genes upregulated in the Rag2 line were annotated as being involved in cell wall, secondary, and hormone metabolism as well as in stress, signaling, and transcriptional responses. Genes downregulated in the Rag2 line were annotated as being involved in photosynthesis and carbon metabolism. Interestingly, two genes (unknown and mitochondrial protease) located within the defined Rag2 locus were expressed significantly higher in the resistant genotype. The expression of a putative NBS-LRR resistant gene within the Rag2 locus was not different between the two soybean lines, but a second NBL-LRR gene located just at the border of the defined Rag2 locus was. Therefore, this gene may be a candidate R gene controlling aphid resistance. PMID:26350764

  9. Thorough investigation of a canine autoinflammatory disease (AID) confirms one main risk locus and suggests a modifier locus for amyloidosis.

    PubMed

    Olsson, Mia; Tintle, Linda; Kierczak, Marcin; Perloski, Michele; Tonomura, Noriko; Lundquist, Andrew; Murén, Eva; Fels, Max; Tengvall, Katarina; Pielberg, Gerli; Dufaure de Citres, Caroline; Dorso, Laetitia; Abadie, Jérôme; Hanson, Jeanette; Thomas, Anne; Leegwater, Peter; Hedhammar, Åke; Lindblad-Toh, Kerstin; Meadows, Jennifer R S

    2013-01-01

    Autoinflammatory disease (AID) manifests from the dysregulation of the innate immune system and is characterised by systemic and persistent inflammation. Clinical heterogeneity leads to patients presenting with one or a spectrum of phenotypic signs, leading to difficult diagnoses in the absence of a clear genetic cause. We used separate genome-wide SNP analyses to investigate five signs of AID (recurrent fever, arthritis, breed specific secondary dermatitis, otitis and systemic reactive amyloidosis) in a canine comparative model, the pure bred Chinese Shar-Pei. Analysis of 255 DNA samples revealed a shared locus on chromosome 13 spanning two peaks of association. A three-marker haplotype based on the most significant SNP (p<2.6×10(-8)) from each analysis showed that one haplotypic pair (H13-11) was present in the majority of AID individuals, implicating this as a shared risk factor for all phenotypes. We also noted that a genetic signature (F ST) distinguishing the phenotypic extremes of the breed specific Chinese Shar-Pei thick and wrinkled skin, flanked the chromosome 13 AID locus; suggesting that breed development and differentiation has played a parallel role in the genetics of breed fitness. Intriguingly, a potential modifier locus for amyloidosis was revealed on chromosome 14, and an investigation of candidate genes from both this and the chromosome 13 regions revealed significant (p<0.05) renal differential expression in four genes previously implicated in kidney or immune health (AOAH, ELMO1, HAS2 and IL6). These results illustrate that phenotypic heterogeneity need not be a reflection of genetic heterogeneity, and that genetic modifiers of disease could be masked if syndromes were not first considered as individual clinical signs and then as a sum of their component parts. PMID:24130694

  10. Efficiency alleles of the Pctr1 modifier locus for plasmacytoma susceptibility.

    PubMed

    Zhang, S L; DuBois, W; Ramsay, E S; Bliskovski, V; Morse, H C; Taddesse-Heath, L; Vass, W C; DePinho, R A; Mock, B A

    2001-01-01

    The susceptibility of BALB/c mice to pristane-induced plasmacytomas is a complex genetic trait involving multiple loci, while DBA/2 and C57BL/6 strains are genetically resistant to the plasmacytomagenic effects of pristane. In this model system for human B-cell neoplasia, one of the BALB/c susceptibility and modifier loci, Pctr1, was mapped to a 5.7-centimorgan (cM) chromosomal region that included Cdkn2a, which encodes p16(INK4a) and p19(ARF), and the coding sequences for the BALB/c p16(INK4a) and p19(ARF) alleles were found to be polymorphic with respect to their resistant Pctr1 counterparts in DBA/2 and C57BL/6 mice (45). In the present study, alleles of Pctr1, Cdkn2a, and D4Mit15 from a resistant strain (BALB/cDAG) carrying DBA/2 chromatin were introgressively backcrossed to the susceptible BALB/c strain. The resultant C.DAG-Pctr1 Cdkn2a D4Mit15 congenic was more resistant to plasmacytomagenesis than BALB/c, thus narrowing Pctr1 to a 1.5-cM interval. Concomitantly, resistant C57BL/6 mice, from which both gene products of the Cdkn2a gene have been eliminated, developed pristane-induced plasma cell tumors over a shorter latency period than the traditionally susceptible BALB/cAn strain. Biological assays of the p16(INK4a) and p19(ARF) alleles from BALB/c and DBA/2 indicated that the BALB/c p16(INK4a) allele was less active than its DBA/2 counterpart in inducing growth arrest of mouse plasmacytoma cell lines and preventing ras-induced transformation of NIH 3T3 cells, while the two p19(ARF) alleles displayed similar potencies in both assays. We propose that the BALB/c susceptibility/modifier locus, Pctr1, is an "efficiency" allele of the p16(INK4a) gene. PMID:11113205

  11. Fine-Mapping the Wheat Snn1 Locus Conferring Sensitivity to the Parastagonospora nodorum Necrotrophic Effector SnTox1 Using an Eight Founder Multiparent Advanced Generation Inter-Cross Population

    PubMed Central

    Cockram, James; Scuderi, Alice; Barber, Toby; Furuki, Eiko; Gardner, Keith A.; Gosman, Nick; Kowalczyk, Radoslaw; Phan, Huyen P.; Rose, Gemma A.; Tan, Kar-Chun; Oliver, Richard P.; Mackay, Ian J.

    2015-01-01

    The necrotrophic fungus Parastagonospora nodorum is an important pathogen of one of the world’s most economically important cereal crops, wheat (Triticum aestivum L.). P. nodorum produces necrotrophic protein effectors that mediate host cell death, providing nutrients for continuation of the infection process. The recent discovery of pathogen effectors has revolutionized disease resistance breeding for necrotrophic diseases in crop species, allowing often complex genetic resistance mechanisms to be broken down into constituent parts. To date, three effectors have been identified in P. nodorum. Here we use the effector, SnTox1, to screen 642 progeny from an eight-parent multiparent advanced generation inter-cross (i.e., MAGIC) population, genotyped with a 90,000-feature single-nucleotide polymorphism array. The MAGIC founders showed a range of sensitivity to SnTox1, with transgressive segregation evident in the progeny. SnTox1 sensitivity showed high heritability, with quantitative trait locus analyses fine-mapping the Snn1 locus to the short arm of chromosome 1B. In addition, a previously undescribed SnTox1 sensitivity locus was identified on the long arm of chromosome 5A, termed here QSnn.niab-5A.1. The peak single-nucleotide polymorphism for the Snn1 locus was converted to the KASP genotyping platform, providing breeders and researchers a simple and cheap diagnostic marker for allelic state at Snn1. PMID:26416667

  12. Insulin resistance and insulin sensitizers.

    PubMed

    Stumvoll, M; Häring, H

    2001-01-01

    Insulin resistance is a key factor in the pathogenesis of type 2 diabetes mellitus and a co-factor in the development of dyslipidaemia, hypertension and atherosclerosis. The causes of insulin resistance include factors such as obesity and physical inactivity, and there may also be genetic factors. The mechanism of obesity-related insulin resistance involves the release of factors from adipocytes which exert a negative effect on glucose metabolism: free fatty acids, tumour necrosis factor-alpha and the recently discovered hormone, resistin. The two resulting abnormalities observed consistently in glucose-intolerant states are impaired suppression of endogenous glucose production, and impaired stimulation of glucose uptake. Among the genetic factors, a polymorphism (Pro12Ala) in the peroxisome proliferator-activated receptor (PPAR) gamma is associated with a reduced risk of type 2 diabetes mellitus and increased insulin sensitivity, primarily that of lipolysis. On the other hand, the association with insulin resistance of a common polymorphism (Gly972Arg) in the insulin receptor substrate 1, long believed to be a plausible candidate gene, is weak at best. This polymorphism may instead be associated with reduced insulin secretion, which, in view of the recent recognition of the insulin signalling system in beta-cells, results in the development of a novel pathogenic concept. Finally, fine-mapping and positional cloning of the susceptibility locus on chromosome 2 resulted in the identification of a polymorphism (UCSNP-43 G/A) in the calpain-10 gene. In non-diabetic Pima Indians, this polymorphism was associated with insulin resistance of glucose disposal. The pharmacological treatment of insulin resistance has recently acquired a novel class of agents: the thiazolidinediones. They act through regulation of PPARgamma-dependent genes and probably interfere favourably with factors released from adipocytes which mediate obesity-associated insulin resistance. PMID:11684868

  13. Host Resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Concepts covered in this chapter (for an undergraduate text book) • Disease resistance is a crucial trait for any crop plant. • The degree of disease resistance varies within plant populations. Much of this variation has a genetic basis. • Plant disease resistance can be broadly categorized into s...

  14. RESISTIVITY METHODS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Resistivity methods were among the first geophysical techniques developed. The basic concept originated with Conrad Schlumberger, who conducted the initial resistivity field tests in Normandy, France during 1912. The resistivity method, employed in its earliest and most conventional form, uses an ex...

  15. Antibiotic Resistance

    MedlinePlus

    Antibiotics are medicines that fight bacterial infections. Used properly, they can save lives. But there is a growing problem of antibiotic resistance. It happens when bacteria change and become able to resist the effects of an antibiotic. Using antibiotics can lead to resistance. ...

  16. LET and ion-species dependence for mutation induction and mutation spectrum on hprt locus in normal human fibroblasts.

    PubMed

    Tsuruoka, Chizuru; Suzuki, Masao; Fujitaka, Kazunobu

    2004-11-01

    We have been studying LET and ion species dependence of RBE in mutation frequency and mutation spectrum of deletion pattern of exons in hprt locus. Normal human skin fibroblasts were irradiated with heavy-ion beams, such as carbon- (290 MeV/u and 135 MeV/u), neon- (230 MeV/u and 400 MeV/u), silicon- (490 MeV/u) and iron- (500 MeV/u) ion beams, generated by Heavy Ion Medical Accelerator in Chiba (HIMAC) at national Institute of Radiological Sciences (NIRS). Mutation induction in hprt locus was detected to measure 6-thioguanine resistant colonies and deletion spectrum of exons was analyzed by multiplex PCR. The LET-RBE curves of mutation induction for carbon- and neon-ion beams showed a peak around 75 keV/micrometers and 155 keV/micrometers, respectively. On the other hand, there observed no clear peak for silicon-ion beams. The deletion spectrum of exons was different in induced mutants among different ion species. These results suggested that quantitative and qualitative difference in mutation occurred when using different ion species even if similar LET values. PMID:15858385

  17. The discovery of the microphthalmia locus and its gene, Mitf

    PubMed Central

    Arnheiter, Heinz

    2010-01-01

    Summary The history of the discovery of the microphthalmia locus and its gene, now called Mitf, is a testament to the triumph of serendipity. Although the first microphthalmia mutation was discovered among the descendants of a mouse that was irradiated for the purpose of mutagenesis, the mutation most likely was not radiation-induced but occurred spontaneously in one of the parents of a later breeding. Although Mitf might eventually have been identified by other molecular genetic techniques, it was first cloned from a chance transgene insertion at the microphthalmia locus. And although Mitf was found to encode a member of a well-known transcription factor family, its analysis might still be in its infancy had Mitf not turned out to be of crucial importance for the physiology and pathology of many distinct organs, including eye, ear, immune system, bone, and skin, and in particular for melanoma. In fact, near seven decades of Mitf research have led to many insights about development, function, degeneration, and malignancies of a number of specific cell types, and it is hoped that these insights will one day lead to therapies benefitting those afflicted with diseases originating in these cell types. PMID:20807369

  18. Rapid publication: Clinical and locus heterogeneity in brachydactyly type C

    SciTech Connect

    Robin, N.H.; Gunay-Aygun, M.; Polinkovsky, A.

    1997-01-31

    Brachydactyly type C is characterized by shortness of the second and fifth middle phalanges and the first metacarpal. It is inherited as an autosomal dominant trait, and is noted for its widely variable clinical phenotype both within and between families. In most families involvement is limited to the hands. However, in some families additional skeletal and nonskeletal findings have been reported. We report on 12 affected members from a 5 generation kindred that segregates a brachydactyly type C phenotype. All affected individuals had shortness principally affecting the second and fifth phalanges and first metacarpal. However, the metacarpal-phalangeal profile indicated that other digital elements were short as well. In addition, one affected individual had a bilateral Madelung deformity, but none had foot involvement. No other non-skeletal findings cosegregated with brachydactyly in this family. Recently, a gene for brachydactyly type C has been localized to 12q24. This was done by studying a large kindred first reported by Haws [1963], which manifests both hand and foot anomalies. Here we present linkage data which excludes the 12q24 locus in our kindred, indicating locus heterogeneity as one explanation for the interfamilial variability described in brachydactyly type C. 33 refs., 2 figs., 2 tabs.

  19. Positional cloning of the mouse saccharin preference (Sac) locus

    PubMed Central

    Bachmanov, Alexander A.; Li, Xia; Reed, Danielle R.; Ohmen, Jeffery D.; Li, Shanru; Chen, Zhenyu; Tordoff, Michael G.; de Jong, Pieter J.; Wu, Chenyan; West, David B.; Chatterjee, Alu; Ross, David A.; Beauchamp, Gary K.

    2013-01-01

    Differences in sweetener intake among inbred strains of mice are partially determined by allelic variation of the saccharin preference (Sac) locus. Genetic and physical mapping limited a critical genomic interval containing Sac to a 194-kb DNA fragment. Sequencing and annotation of this region identified a gene (Tas1r3) encoding the third member of the T1R family of putative taste receptors, T1R3. Introgression by serial backcrossing of the 194-kb chromosomal fragment containing the Tas1r3 allele from the high-sweetener preferring C57BL/6ByJ strain onto the genetic background of the low-sweetener preferring 129P3/J strain rescued its low sweetener preference phenotype. Polymorphisms of Tas1r3 that are likely to have functional significance were identified using analysis of genomic sequences and sweetener preference phenotypes of genealogically distant mouse strains. Tas1r3 has two common haplotypes, consisting of six single nucleotide polymorphisms: one haplotype was found in mouse strains with elevated sweetener preference and the other in strains relatively indifferent to sweeteners. This study provides compelling evidence that Tas1r3 is equivalent to the Sac locus and that the T1R3 receptor responds to sweeteners. PMID:11555487

  20. Thought recognition, locus of control, and adolescent well-being.

    PubMed

    Kelley, T M; Stack, S A

    2000-01-01

    This paper reviews the underlying assumptions and principles of a new psychological paradigm, Psychology of Mind/Health Realization (POM/HR). A core concept of POM/HR, thought recognition, is then compared with locus of control (LOC), a well-known psychological construct. Next, the relationship of LOC to self-reported happiness and satisfaction is examined from the perspective of POM/HR, using a sample of 1,872 at-risk adolescents from 17 nations. The findings support POM/HR predictions that (1) locus of control would account for a slight portion of the variance in adolescent happiness and satisfaction, (2) circumstances that are external in nature would account for additional variance in happiness and satisfaction, and (3) there would be little difference in self-reported happiness and satisfaction between adolescents self-reporting high and low internal LOC. Further, it was conjectured that the adolescents mistook superficial emotions, such as excitement and security, for genuine feelings of well-being. Finally, the implications for prevention and intervention efforts with at-risk adolescents are discussed. PMID:11130596

  1. Cynomolgus macaque (Macaca fascicularis) immunoglobulin heavy chain locus description.

    PubMed

    Yu, Guo-Yun; Mate, Suzanne; Garcia, Karla; Ward, Michael D; Brueggemann, Ernst; Hall, Matthew; Kenny, Tara; Sanchez-Lockhart, Mariano; Lefranc, Marie-Paule; Palacios, Gustavo

    2016-07-01

    Cynomolgus macaques (Macaca fascicularis) have become an important animal model for biomedical research. In particular, it is the animal model of choice for the development of vaccine candidates associated with emerging dangerous pathogens. Despite their increasing importance as animal models, the cynomolgus macaque genome is not fully characterized, hindering molecular studies for this model. More importantly, the lack of knowledge about the immunoglobulin (IG) locus organization directly impacts the analysis of the humoral response in cynomolgus macaques. Recent advances in next generation sequencing (NGS) technologies to analyze IG repertoires open the opportunity to deeply characterize the humoral immune response. However, the IG locus organization for the animal is required to completely dissect IG repertoires. Here, we describe the localization and organization of the rearranging IG heavy (IGH) genes on chromosome 7 of the cynomolgus macaque draft genome. Our annotation comprises 108 functional genes which include 63 variable (IGHV), 38 diversity (IGHD), and 7 joining (IGHJ) genes. For validation, we provide RNA transcript data for most of the IGHV genes and all of the annotated IGHJ genes, as well as proteomic data to validate IGH constant genes. The description and annotation of the rearranging IGH genes for the cynomolgus macaques will significantly facilitate scientific research. This is particularly relevant to dissect the immune response during vaccination or infection with dangerous pathogens such as Ebola, Marburg and other emerging pathogens where non-human primate models play a significant role for countermeasure development. PMID:27233955

  2. Asynchronous DNA replication within the human. beta. -globin gene locus

    SciTech Connect

    Epner, E.; Forrester, W.C.; Groudine, M. )

    1988-11-01

    The timing of DNA replication of the human {beta}-globin gene locus has been studied by blot hybridization of newly synthesized BrdUrd-substituted DNA from cells in different stages of the S phase. Using probes that span >120 kilobases across the human {beta}-globin gene locus, the authors show that the majority of this domain replicates in early S phase in the human erythroleukemia cell line K562 and in middle-to-late S phase in the lymphoid cell line Manca. However, in K562 cells three small regions display a strikingly different replication pattern than adjacent sequences. These islands, located in the inter-{gamma}-globin gene region and approximately 20 kilobases 5' to the {epsilon}-globin gene and 20 kilobases 3' to the {beta}-globin gene, replicate later and throughout S phase. A similar area is also present in the {alpha}-globin gene region in K562 cells. They suggest that these regions may represent sites of termination of replication forks.

  3. Interchromosomal gene conversion at an endogenous human cell locus.

    PubMed Central

    Quintana, P J; Neuwirth, E A; Grosovsky, A J

    2001-01-01

    To examine the relationship between gene conversion and reciprocal exchange at an endogenous chromosomal locus, we developed a reversion assay in a thymidine kinase deficient mutant, TX545, derived from the human lymphoblastoid cell line TK6. Selectable revertants of TX545 can be generated through interchromosomal gene conversion at the site of inactivating mutations on each tk allele or by reciprocal exchange that alters the linkage relationships of inactivating polymorphisms within the tk locus. Analysis of loss of heterozygosity (LOH) at intragenic polymorphisms and flanking microsatellite markers was used to initially evaluate allelotypes in TK(+) revertants for patterns associated with either gene conversion or crossing over. The linkage pattern in a subset of convertants was then unambiguously established, even in the event of prereplicative recombinational exchanges, by haplotype analysis of flanking microsatellite loci in tk(-/-) LOH mutants collected from the tk(+/-) parental convertant. Some (7/38; 18%) revertants were attributable to easily discriminated nonrecombinational mechanisms, including suppressor mutations within the tk coding sequence. However, all revertants classified as a recombinational event (28/38; 74%) were attributed to localized gene conversion, representing a highly significant preference (P < 0.0001) over gene conversion with associated reciprocal exchange, which was never observed. PMID:11404339

  4. Evolution of haplotypes at the DRD2 locus

    SciTech Connect

    Castiglione, C.M.; Deinard, A.S.; Speed, W.C.

    1995-12-01

    We present here the first evolutionary perspective on haplotypes at DRD2, the locus for the dopamine D{sub 2} receptor. The dopamine D{sub 2} receptor plays a critical role in the functioning of many neural circuits in the human brain. If functionally relevant variation at the DRD2 locus exists, understanding the evolution of haplotypes on the basis of polymorphic sites encompassing the gene should provide a powerful framework for identifying that variation. Three DRD2 polymorphisms (TaqI {open_quotes}A{close_quotes} and {open_quotes}B{close_quotes} RFLPs and the (CA){sub n} short tandem repeat polymorphism) encompassing the coding sequences have been studied in 15 populations; these markers are polymorphic in all the populations studied, and they display strong and significant linkage disequilibria with each other. The common haplotypes for the two TaqI RFLPs are separately derived from the ancestral haplotype but predate the spread of modern humans around the world. The knowledge of how the various haplotypes have evolved, the allele frequencies of the haplotypes in human populations, and the physical relationships of the polymorphisms to each other and to the functional parts of the gene should now allow proper design and interpretation of association studies. 48 refs., 2 figs., 6 tabs.

  5. The Locus analytical framework for indoor localization and tracking applications

    NASA Astrophysics Data System (ADS)

    Segou, Olga E.; Thomopoulos, Stelios C. A.

    2015-05-01

    Obtaining location information can be of paramount importance in the context of pervasive and context-aware computing applications. Many systems have been proposed to date, e.g. GPS that has been proven to offer satisfying results in outdoor areas. The increased effect of large and small scale fading in indoor environments, however, makes localization a challenge. This is particularly reflected in the multitude of different systems that have been proposed in the context of indoor localization (e.g. RADAR, Cricket etc). The performance of such systems is often validated on vastly different test beds and conditions, making performance comparisons difficult and often irrelevant. The Locus analytical framework incorporates algorithms from multiple disciplines such as channel modeling, non-uniform random number generation, computational geometry, localization, tracking and probabilistic modeling etc. in order to provide: (a) fast and accurate signal propagation simulation, (b) fast experimentation with localization and tracking algorithms and (c) an in-depth analysis methodology for estimating the performance limits of any Received Signal Strength localization system. Simulation results for the well-known Fingerprinting and Trilateration algorithms are herein presented and validated with experimental data collected in real conditions using IEEE 802.15.4 ZigBee modules. The analysis shows that the Locus framework accurately predicts the underlying distribution of the localization error and produces further estimates of the system's performance limitations (in a best-case/worst-case scenario basis).

  6. Quantitative trait locus analysis for hemostasis and thrombosis

    PubMed Central

    Sa, Qila; Hart, Erika; Hill, Annie E.; Nadeau, Joseph H.

    2009-01-01

    Susceptibility to thrombosis varies in human populations as well as many in inbred mouse strains. The objective of this study was to characterize the genetic control of thrombotic risk on three chromosomes. Previously, utilizing a tail-bleeding/rebleeding assay as a surrogate of hemostasis and thrombosis function, three mouse chromosome substitution strains (CSS) (B6-Chr5A/J, Chr11A/J, Chr17A/J) were identified (Hmtb1, Hmtb2, Hmtb3). The tailbleeding/rebleeding assay is widely used and distinguishes mice with genetic defects in blood clot formation or dissolution. In the present study, quantitative trait locus (QTL) analysis revealed a significant locus for rebleeding (clot stability) time (time between cessation of initial bleeding and start of the second bleeding) on chromosome 5, suggestive loci for bleeding time (time between start of bleeding and cessation of bleeding) also on chromosomes 5, and two suggestive loci for clot stability on chromosome 17 and one on chromosome 11. The three CSS and the parent A/J had elevated clot stability time. There was no interaction of genes on chromosome 11 with genes on chromosome 5 or chromosome 17. On chromosome 17, twenty-three candidate genes were identified in synteny with previously identified loci for thrombotic risk on human chromosome 18. Thus, we have identified new QTLs and candidate genes not previously known to influence thrombotic risk. PMID:18787898

  7. A transposon insertion in FLOWERING LOCUS T is associated with delayed flowering in Brassica rapa.

    PubMed

    Zhang, Xueming; Meng, Lin; Liu, Bo; Hu, Yunyan; Cheng, Feng; Liang, Jianli; Aarts, Mark G M; Wang, Xiaowu; Wu, Jian

    2015-12-01

    Long days and vernalization accelerate the transition from vegetative growth to reproductive growth in Brassica rapa. Bolting before plants reach the harvesting stage is a serious problem in B. rapa vegetable crop cultivation. The genetic dissection of flowering time is important for breeding of premature bolting-resistant B. rapa crops. Using a recombinant inbred line (RIL) population, we twice detected two major quantitative trait loci (QTLs) for flowering time in two different growing seasons that were located on chromosomes A02 and A07, respectively. We hypothesized that an orthologue of the Arabidopsis thaliana FLOWERING LOCUS T (FT) gene, named as BrFT2, was the candidate gene underlying the QTL localized to A07. A transposon insertion in the second intron of BrFT2 was detected in one of the parental lines, which was predicted to generate a loss-of-function allele. Transcription analysis revealed that the BrFT2 transcript was not present in the parental line that harbored the mutated allele. RILs carrying only the mutated BrFT2 allele showed delayed flowering regardless of growing seasons when compared to RILs carrying the wild-type BrFT2 allele. These data suggest that BrFT2 is involved in flowering time regulation in controlling flowering time in B. rapa. PMID:26706072

  8. The Regulation of White Locus Expression: A Dominant Mutant Allele at the White Locus of DROSOPHILA MELANOGASTER

    PubMed Central

    Bingham, Paul M.

    1980-01-01

    A new mutant allele (wDZL) at the white locus of Drosophila melanogaster is dominant to the wild-type allele, but apparently only when the two alleles are synapsed. When chromosomal rearrangements prevent somatic pairing between the two white alleles, wDZL is rendered recessive to wild type. This observation suggests that the dominance of wDZL is sensitive to a synapsis (transvection) effect. On the basis of this and other properties, it is proposed that wDZL causes the repression of transcription of a synapsed w+ allele, but not of a w+ allele elsewhere in the same nucleus. One model to account for this supposes that wDZL produces a repressor of white-locus transcription. This repressor is presumed to be so unstable that other white genes, removed from wDZL but in the same nucleus, are not detectably repressed. These properties may be simply understood if it is assumed that the repressor produced by the wDZL allele is an RNA molecule. PMID:17249039

  9. Antimicrobial (Drug) Resistance

    MedlinePlus

    ... Antimicrobial (Drug) Resistance Antibiotic-Resistant Mycobacterium tuberculosis (TB) Methicillin-Resistant Staphylococcus aureus (MRSA) Vancomycin-Resistant Enterococci (VRE) Multidrug-Resistant Neisseria ...

  10. Dynamic evolution of resistance gene analogs in the orthologous genomic regions of powdery mildew resistance gene MlIW170 in Triticum dicoccoides and Aegilops tauschii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat is one of the most important staple grain crops in the world. Powdery mildew disease caused by Blumeria graminis f.sp. tritici can result in significant losses in both grain yield and quality in wheat. In this study, the wheat powdery mildew resistance gene MlIW170 locus located on the short ...

  11. Drug resistance. K13-propeller mutations confer artemisinin resistance in Plasmodium falciparum clinical isolates.

    PubMed

    Straimer, Judith; Gnädig, Nina F; Witkowski, Benoit; Amaratunga, Chanaki; Duru, Valentine; Ramadani, Arba Pramundita; Dacheux, Mélanie; Khim, Nimol; Zhang, Lei; Lam, Stephen; Gregory, Philip D; Urnov, Fyodor D; Mercereau-Puijalon, Odile; Benoit-Vical, Françoise; Fairhurst, Rick M; Ménard, Didier; Fidock, David A

    2015-01-23

    The emergence of artemisinin resistance in Southeast Asia imperils efforts to reduce the global malaria burden. We genetically modified the Plasmodium falciparum K13 locus using zinc-finger nucleases and measured ring-stage survival rates after drug exposure in vitro; these rates correlate with parasite clearance half-lives in artemisinin-treated patients. With isolates from Cambodia, where resistance first emerged, survival rates decreased from 13 to 49% to 0.3 to 2.4% after the removal of K13 mutations. Conversely, survival rates in wild-type parasites increased from ≤0.6% to 2 to 29% after the insertion of K13 mutations. These mutations conferred elevated resistance to recent Cambodian isolates compared with that of reference lines, suggesting a contemporary contribution of additional genetic factors. Our data provide a conclusive rationale for worldwide K13-propeller sequencing to identify and eliminate artemisinin-resistant parasites. PMID:25502314

  12. Goal Orientations, Locus of Control and Academic Achievement in Prospective Teachers: An Individual Differences Perspective

    ERIC Educational Resources Information Center

    Bulus, Mustafa

    2011-01-01

    The aim of this study is to investigate the role of the prospective teachers' locus of control in goal orientations and of both orientations in academic achievement. The participants were 270 undergraduate students studying in different majors at the Faculty of Education in Pamukkale University. Goal Orientations and Locus of Control Scales were…

  13. Authoritarian Child Rearing, Parental Locus of Control, and the Child's Behavior Style.

    ERIC Educational Resources Information Center

    Janssens, Jan M. A. M.

    1994-01-01

    Examined relationships among childrearing, parental locus of control about childrearing, and child's behavior style. Found that parents who perceived their child's behavior as either externalizing or internalizing had a weak internal locus of control and were more authoritarian. Perceived externalizing child behavior was positively related to…

  14. The Effect of Locus of Control on Message Acceptance and Recall.

    ERIC Educational Resources Information Center

    Cole, Catherine A.; Singh, Surendra

    Locus of control is a personality trait that influences human behavior in many situations. Internal-external control reactions to a persuasive message and the recall of the message were examined in two studies. In the first study, 35 undergraduate students' locus of control was measured using Duttweiler's Internal Control Measure. On the basis of…

  15. A Comparative Test of Locus on Control Measures and IQ as Predictors of Children's Task Performance.

    ERIC Educational Resources Information Center

    LaVoie, Joseph C.; Adams, Gerald R.

    In this study, locus of control and IQ were compared to assess the power of each as a predictor of performance on academic and non-academic tasks. Four locus of control scales: the Intellectual Achievement Responsibility Scale, the Academic Achievement Accountability Questionnaire, the Rotter I-E scale, the Origin-Pawn measure and the Iowa Tests…

  16. Adult Children of Workaholics: Self-Concept, Anxiety, Depression, and Locus of Control.

    ERIC Educational Resources Information Center

    Robinson, Bryan E.; Kelley, Lisa

    1998-01-01

    Adult children of workaholics were compared with adult children of nonworkaholics on self-concept, anxiety, depression, and external locus of control. Results indicate greater depression and external locus of control among the offspring of workaholics. Children of workaholic fathers also experienced higher anxiety. Self-concept was not related to…

  17. Health Locus of Control and Preventive Behaviour among Students of Music

    ERIC Educational Resources Information Center

    Spahn, Claudia; Burger, Thorsten; Hildebrandt, Horst; Seidenglanz, Karin

    2005-01-01

    The present study investigated health locus of control, preventive behaviour and previous playing-related health problems of music students; 326 students of music (58% female, mean age 22 years) filled in the Locus of Control Inventory for Illness and Health (Lohaus and Schmitt, 1989) and the Epidemiological Questionnaire for Musicians (Spahn,…

  18. Are Kibbutz Children Different from City Children in Locus of Control, Anxiety, and Persistence?

    ERIC Educational Resources Information Center

    Lufi, Dubi; Tenenbaum, Gershon

    1993-01-01

    Examined personality traits of kibbutz children (n=130) and compared them to those of city children (n=142). Children completed Revised Children's Manifest Anxiety Scale, Locus of Control for Children, and Persistence Scale for Children. Found differences between kibbutz and city children in locus of control, anxiety, and persistence, and also…

  19. Validity of a Measure of Children's Health Locus of Control: A Second-Order Factor Analysis.

    ERIC Educational Resources Information Center

    Thompson, Bruce; And Others

    The study reported in this paper investigated the structure of the health locus of control beliefs of elementary school children using second-order factor analysis and the measurement characteristics of the Multidimensional Health Locus of Control (MHLC) Scales. Changes of wording were made in 10 of the MHLC Scales items in order to improve the…

  20. Predictors of Parental Locus of Control in Mothers of Pre- and Early Adolescents

    ERIC Educational Resources Information Center

    Freed, Rachel D.; Tompson, Martha C.

    2011-01-01

    Parental locus of control refers to parents' perceived power and efficacy in child-rearing situations. This study explored parental locus of control and its correlates in 160 mothers of children ages 8 to 14 cross-sectionally and 1 year later. Maternal depression, maternal expressed emotion, and child internalizing and externalizing behavior were…

  1. Locus of Control, Field Dependence-Independence as Factors in Learning and Memory.

    ERIC Educational Resources Information Center

    Piotrowski, Chris

    The focus of research on cognitive processes has shifted toward an examination of the relationship between memory and interindividual differences of personality. A review of the research on two such personality traits (i.e., locus of control and field dependence-independence) shows that studies of locus of control as a factor in learning and…

  2. Locus of Control, Attributional Style and Discipline Problems in Secondary Schools

    ERIC Educational Resources Information Center

    Tony, Tam Shui Kee

    2003-01-01

    This article presents the findings of a study hypothesizing that school discipline problems are a maladaptive response to the demand of the school environment as a result of deficits in the area of locus of control and attributional style. The findings indicate that an external orientation of locus of control and a passive pattern of attribution…

  3. Locus of Semantic Interference in Picture Naming: Evidence from Dual-Task Performance

    ERIC Educational Resources Information Center

    Piai, Vitória; Roelofs, Ardi; Schriefers, Herbert

    2014-01-01

    Disagreement exists regarding the functional locus of semantic interference of distractor words in picture naming. This effect is a cornerstone of modern psycholinguistic models of word production, which assume that it arises in lexical response-selection. However, recent evidence from studies of dual-task performance suggests a locus in…

  4. Locus of Control and Self-Esteem in Indian and White Students.

    ERIC Educational Resources Information Center

    Martin, James C.

    1976-01-01

    The development and relationship of two dimensions of personality, self esteem and locus of control, were examined in a study of 763 fourth, eighth, and twelfth grade Indian and white children selected from 22 Oklahoma public schools. The students were given the Coopersmith Self-Esteem Inventory and Nowicky-Strickland Locus of Control Scale during…

  5. Internal-External Locus of Control in Middle and Later Life: The Search for Construct Validation.

    ERIC Educational Resources Information Center

    Bielby, Denise D.; Siegler, Ilene C.

    This study validates the developmental nature of internal-external locus of control in middle and old age. Longitudinal stability of locus of control in the face of particular changes in social milieu common during the transition from middle to late life was contrasted with that of verbal intelligence, a known stable characteristic, and that of…

  6. Locus of Control and Value Orientations of Adult Learners in Postsecondary Education.

    ERIC Educational Resources Information Center

    Linder, Fredric; And Others

    The locus of control and value orientations of undergraduate and graduate students in schools of business and education at Virginia Commonwealth University were assessed. Rotter's Internal-External Locus of Control Scale and Rokeach's Value Survey were administered to 1,139 students who ranged in age from 18 to over 40. Results indicated that…

  7. Criterion-Related Validity of the Nowicki-Strickland Locus of Control Scale with Academic Achievement.

    ERIC Educational Resources Information Center

    Nunn, Gary D.; And Others

    1986-01-01

    Investigated the relationships between student locus of control and academic achievement in grades five through eight. The Nowicki-Strickland Locus of Control Scale (NSLOCS) was used to measure motivation, and the Iowa Tests of Basic Skills (ITBS) to assess academic achievement. Results indicated moderate inverse relationships between level of…

  8. Effects of locus of control, occupational stress, and psychological distress on job satisfaction among nurses.

    PubMed

    Jain, V K; Lall, R; McLaughlin, D G; Johnson, W B

    1996-06-01

    This study evaluated the effects of locus of control, occupational stress, and psychological symptom distress on reported job satisfaction in a sample of 34 practicing nurses. As predicted, greater work-related stress and higher psychological symptom distress were significantly negatively correlated with job satisfaction. External locus of control was also negatively associated with job satisfaction. PMID:8816047

  9. Structure of the Catfish IGH Locus: Analysis of the Region Including the Single Functional IGHM Gene

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The catfish IGH locus is large (~1Mb) and complex, having undergone multiple internal duplications and transpositions. To define the structure of the locus that contains the single expressed IGHM gene, two overlapping bacterial-artificial-chromosome (BAC) clones spanning the most 3’ end of the chann...

  10. Locus of Control as It Relates to the Teaching Style of Elementary Teachers

    ERIC Educational Resources Information Center

    Ture, Abidemi

    2013-01-01

    This research explored the relationship between elementary teachers' locus of control and teaching style. This research observed elementary teachers in their classrooms coupled with data gathered from information sheets, surveys, and interviews to determine if a relationship exists between the locus of control of the elementary teachers and…

  11. Development of Locus of Control: A Review and Model for Further Exploration.

    ERIC Educational Resources Information Center

    Olejnik, Anthony B.

    This paper applies a developmental perspective to locus of control studies. Contingency awareness established during infancy and early childhood is viewed as the basis for the development of locus of control expectancies. Expectancies of contingent reinforcement involve a cognitive component and can be viewed in Piagetian terms as the development…

  12. Relationship of Personality and Locus of Control With Employment Outcomes among Participants with Spinal Cord Injury

    ERIC Educational Resources Information Center

    Krause, James S.; Broderick, Lynne

    2006-01-01

    We investigated relationships among personality, locus of control, and current post-injury employment status for 1,391 participants with spinal cord injury. Participants with higher internality locus-of-control scores and activity scores (personality) reported more favorable employment outcomes. Higher scores on chance and powerful others (locus…

  13. An Examination of Locus of Control, Epistemological Beliefs and Metacognitive Awareness in Preservice Early Childhood Teachers

    ERIC Educational Resources Information Center

    Bedel, Emine Ferda

    2012-01-01

    This study aims to explore the locus of control, epistemological beliefs and metacognitive awareness levels of preservice early childhood education teachers and to determine the interrelations among these variables. 206 teacher candidates have been asked to fill out Rotter's Internal-External Locus of Control Scale, Central Epistemological Beliefs…

  14. Metacognition: As a Predictor of One's Academic Locus of Control

    ERIC Educational Resources Information Center

    Arslan, Serhat; Akin, Ahmet

    2014-01-01

    The purpose of this study is to examine the effect of metacognition on one's academic locus of control. The study's sample group consists of 451 university students enrolled in various programs at Sakarya University, Turkey. In this study, the Metacognitive Awareness Inventory and the Academic Locus of Control Scale were used. The…

  15. Self Esteem, Locus of Control and Multidimensional Perfectionism as the Predictors of Subjective Well Being

    ERIC Educational Resources Information Center

    Karatas, Zeynep; Tagay, Ozlem

    2012-01-01

    The purpose of this study is to determine whether there is a relationship between self-esteem, locus of control and multidimensional perfectionism, and the extent to which the variables of self-esteem, locus of control and multidimensional perfectionism contribute to the prediction of subjective well-being. The study was carried out with 318 final…

  16. Social Self-Efficacy, Academic Locus of Control, and Internet Addiction

    ERIC Educational Resources Information Center

    Iskender, Murat; Akin, Ahmet

    2010-01-01

    The purpose of this research is to examine the relationship of internet addiction, social self-efficacy, and academic locus of control. Participants were 311 university students who completed a questionnaire package that included the Online Cognition Scale, the Academic Locus of Control Scale, and the Perceived Social Self-efficacy Scale. The…

  17. A Study to Investigate the Relationship between Locus of Control and Academic Achievement of Students

    ERIC Educational Resources Information Center

    Gujjar, Aijaz Ahmed; Aijaz, Rukhma

    2014-01-01

    Motivation is regarded as the alpha and omega of learning. It is the heart of teaching learning process. Motivation is defined as an internal state that arouses, directs, and maintains the behavior over time. Thus motivation is the pivotal component of learning and locus of control which is one of the important factors it stems from. Locus of…

  18. Grades--Who's to Blame? Student Evaluation of Teaching and Locus of Control

    ERIC Educational Resources Information Center

    Grimes, Paul W.; Millea, Meghan J.; Woodruff, Thomas W.

    2004-01-01

    The authors examine the relationship between students' locus of control and their evaluation of teaching in a traditional principles of economics course. Locus of control is a psychological construct that identifies an individual's beliefs about the degree of personal control that can be exercised over his or her environment. Students with an…

  19. Locus of Control and Task Effects in Mother-Son Interactions.

    ERIC Educational Resources Information Center

    Mead-Fox, Merrill F.; Kralj, Mary M.

    This study examines the interaction of mother-son dyads as a function of mothers' and sons' locus of control and the demand characteristics of specific tasks. The subjects were 32 third grade boys from parochial schools in the District of Columbia area and their mothers. They were assigned to internal or external locus of control groups based on a…

  20. Polymorphisms in pilin glycosylation Locus of Neisseria meningitidis expressing class II pili.

    PubMed

    Kahler, C M; Martin, L E; Tzeng, Y L; Miller, Y K; Sharkey, K; Stephens, D S; Davies, J K

    2001-06-01

    We have located a locus, pgl, in Neisseria meningitidis strain NMB required for the glycosylation of class II pili. Between five and eight open reading frames (ORFs) (pglF, pglB, pglC, pglB2, orf2, orf3, orf8, and avtA) were present in the pgl clusters of different meningococcal isolates. The Class I pilus-expressing strains Neisseria gonorrhoeae MS11 and N. meningitidis MC58 each contain a pgl cluster in which orf2 and orf3 have been deleted. Strain NMB and other meningococcal isolates which express class II type IV pili contained pgl clusters in which pglB had been replaced by pglB2 and an additional novel ORF, orf8, had been inserted between pglB2 and pglC. Insertional inactivation of the eight ORFs of the pgl cluster of strain NMB showed that pglF, pglB2, pglC, and pglD, but not orf2, orf3, orf8, and avtA, were necessary for pilin glycosylation. Pilin glycosylation was not essential for resistance to normal human serum, as pglF and pglD mutants retained wild-type levels of serum resistance. Although pglB2 and pglC mutants were significantly sensitive to normal human serum under the experimental conditions used, subsequent examination of the encapsulation phenotypes revealed that pglB2 and pglC mutants expressed almost 50% less capsule than wild-type NMB. A mutation in orf3, which did not affect pilin glycosylation, also resulted in a 10% reduction in capsule expression and a moderately serum sensitive phenotype. On the basis of these results we suggest that pilin glycosylation may proceed via a lipid-linked oligosaccharide intermediate and that blockages in this pathway may interfere with capsular transport or assembly. PMID:11349019

  1. Identification of Genetic Loci Affecting the Severity of Symptoms of Hirschsprung Disease in Rats Carrying Ednrbsl Mutations by Quantitative Trait Locus Analysis

    PubMed Central

    Torigoe, Daisuke; Lei, Chuzhao; Lan, Xianyong; Chen, Hong; Sasaki, Nobuya; Wang, Jinxi; Agui, Takashi

    2015-01-01

    Hirschsprung’s disease (HSCR) is a congenital disease in neonates characterized by the absence of the enteric ganglia in a variable length of the distal colon. This disease results from multiple genetic interactions that modulate the ability of enteric neural crest cells to populate developing gut. We previously reported that three rat strains with different backgrounds (susceptible AGH-Ednrbsl/sl, resistant F344-Ednrbsl/sl, and LEH-Ednrbsl/sl) but the same null mutation of Ednrb show varying severity degrees of aganglionosis. This finding suggests that strain-specific genetic factors affect the severity of HSCR. Consistent with this finding, a quantitative trait locus (QTL) for the severity of HSCR on chromosome (Chr) 2 was identified using an F2 intercross between AGH and F344 strains. In the present study, we performed QTL analysis using an F2 intercross between the susceptible AGH and resistant LEH strains to identify the modifier/resistant loci for HSCR in Ednrb-deficient rats. A significant locus affecting the severity of HSCR was also detected within the Chr 2 region. These findings strongly suggest that a modifier gene of aganglionosis exists on Chr 2. In addition, two potentially causative SNPs (or mutations) were detected upstream of a known HSCR susceptibility gene, Gdnf. These SNPs were possibly responsible for the varied length of gut affected by aganglionosis. PMID:25790447

  2. Two forms of loops generate the chromatin conformation of the immunoglobulin heavy chain gene locus

    PubMed Central

    Guo, Changying; Gerasimova, Tatiana; Hao, Haiping; Ivanova, Irina; Chakraborty, Tirtha; Selimyan, Roza; Oltz, Eugene M.; Sen, Ranjan

    2013-01-01

    SUMMARY The immunoglobulin heavy chain (IgH) gene locus undergoes radial re-positioning within the nucleus and locus contraction in preparation for gene recombination. We demonstrate that IgH locus conformation involves two levels of chromosomal compaction. At the first level the locus folds into several multi-looped domains. One such domain at the 3′ end of the locus requires an enhancer, Eμ; two other domains at the 5′ end are Eμ-independent. At the second level, these domains are brought into spatial proximity by Eμ-dependent interactions with specific sites within the VH region. Eμ is also required for radial re-positioning of IgH alleles indicating its essential role in large scale chromosomal movements in developing lymphocytes. Our observations provide a comprehensive view of the conformation of IgH alleles in pro-B cells and the mechanisms by which it is established. PMID:21982154

  3. Biochemical Analysis of Genome Functions Using Locus-Specific Chromatin Immunoprecipitation Technologies

    PubMed Central

    Fujita, Toshitsugu; Fujii, Hodaka

    2016-01-01

    To isolate specific genomic regions that retain their molecular interactions, allowing direct identification of chromatin-bound molecules, we developed two locus-specific chromatin immunoprecipitation (locus-specific ChIP) technologies, insertional ChIP (iChIP) and engineered DNA-binding molecule-mediated ChIP (enChIP) using the clustered regularly interspaced short palindromic repeats (CRISPR) system or transcription activator-like (TAL) proteins. Essentially, a locus-specific ChIP consists of locus-tagging and affinity purification and can be combined with downstream analyses to identify molecules associated with the target genomic regions. In this review, we discuss the applications of locus-specific ChIP to analyze the genome functions, including transcription and epigenetic regulation. PMID:26819551

  4. Discriminating among single locus models using small pedigrees.

    PubMed

    Beaty, T H

    1980-01-01

    Simulated small pedigrees (2 parents, 4 offspring) were used to illustrate the applications and limitations of a "model choice" approach designed to detect genetic heterogeneity in familial diseases. While it is possible to identify groups of pedigrees which have different genetic causes for quanitative phenotypic trait(s), theoretical limitations on discriminating between 4 single locus models exist for certain pedigree structures. These limitations originate from the overlapping phenotypic predictions of the various genetic models. Such limitations must be carefully considered in the design of genetic studies. Studies aimed at detecting genetic heterogeneity in familial diseases should limit the different genetic models being considered and tailor the sampling strategy to avoid collecting pedigrees which are non-informative for certain comparisons. PMID:7424975

  5. A 12 megabase restriction map at the cystic fibrosis locus.

    PubMed Central

    Fulton, T R; Bowcock, A M; Smith, D R; Daneshvar, L; Green, P; Cavalli-Sforza, L L; Donis-Keller, H

    1989-01-01

    We have constructed a physical map of the chromosomal region containing the cystic fibrosis locus using seven DNA markers and pulsed-field gel electrophoresis methods. The map includes cleavage sites for 8 rare-cutting restriction enzymes and spans over 12 megabases (Mb) of DNA, with one unlinked probe covering an additional 5 Mb. To our knowledge, this is the largest segment of human DNA which has been restriction-mapped to date. We can identify thirteen putative HTF islands spaced at intervals of 0.3-3.2 Mb. The region between loci D7S8 and MET, where the CF gene lies, includes 1.4-1.9 Mb of DNA. Images PMID:2911467

  6. Search for a schizophrenia susceptibility locus of human chromosome 22

    SciTech Connect

    Coon, H.; Hoff, M.; Holik, J.

    1994-06-15

    We used 10 highly informative DNA polymorphic markers and genetic linkage analysis to examine whether a gene locus predisposing to schizophrenia is located on chromosome 22, in 105 families with schizophrenia and schizoaffective disorder. The LOD score method, including analysis for heterogeneity, provided no conclusive evidence of linkage under a dominant, recessive, or penetrance free model of inheritance. Affected sib-pair analysis was inconclusive. Affected Pedigree Member (APM) analysis gave only suggestive evidence for linkage. Multipoint APM analysis, using 4 adjacent loci including D22S281 and IL2RB, a region of interest from the APM analysis, gave non-significant results for the three different weighting functions. 18 refs., 1 fig., 7 tabs.

  7. Social decentering and locus of control in children.

    PubMed

    Deysach, R E; Keller, H R; Ross, A W; Hiers, T G

    1975-07-01

    Relationships beteen social decentering, personality variables, and social competence were investigated for children attending a seven-week therapeutic summer camp. Ss were 23 males and females ranging in age from 10 to 13 years old had been referred to the camp because they lacked age-appropriate social skills. Feffer's Role Taking Task was used to measure social decentering, and counselor ratings of camper adjustment were measures of social competence. Predicted positive relationships between decentering and competence were found. Striking sex differences were found, however, when comparisons were made between social decentering and two personality variables--the Nowicki-Strickland Locus of Control Scale and the Kiddie Mach. Predicted negative correlations were found between Role Taking Task scores and externality and machiavellianism for females, but not for males. Implications concerning age by sex interactions in the study of personality correlates of social decentering were discussed. PMID:1195148

  8. The Effects of Locus Coeruleus and Norepinephrine in Methamphetamine Toxicity

    PubMed Central

    Ferrucci, Michela; Giorgi, Filippo S; Bartalucci, Alessia; Busceti, Carla L; Fornai, Francesco

    2013-01-01

    The activity of locus coeruleus (LC) neurons has been extensively investigated in a variety of behavioural states. In fact this norepinephrine (NE)-containing nucleus modulates many physiological and pathological conditions including the sleep-waking cycle, movement disorders, mood alterations, convulsive seizures, and the effects of drugs such as psychostimulants and opioids. This review focuses on the modulation exerted by central NE pathways on the behavioural and neurotoxic effects produced by the psychostimulant methamphetamine, essentially the modulation of the activity of mesencephalic dopamine (DA) neurons. In fact, although NE in itself mediates some behavioural effects induced by methamphetamine, NE modulation of DA release is pivotal for methamphetamine-induced behavioural states and neurotoxicity. These interactions are discussed on the basis of the state of the art of the functional neuroanatomy of central NE- and DA systems. Emphasis is given to those brain sites possessing a remarkable overlapping of both neurotransmitters. PMID:23814540

  9. Genetic mapping of a locus predisposing to human colorectal cancer

    SciTech Connect

    Peltomaeki, P.; Aaltonen, L.A.; Pylkkaenen, L.; Chappelle, A. de la ); Sistonen, P. Finnish Red Cross Blood Transfusion Service, Helsinki ); Mecklin, J.P. ); Haervinen, H. ); Green, J.S. ); Jass, J.R. ); Weber, J.L. ); Leach, F.S.; Petersen, G.M.; Hamilton, S.R.; Vogelstein, B. Johns Hopkins Hospital, Baltimore, MD )

    1993-05-07

    Genetic linkage analysis was used to determine whether a specific chromosomal locus could be implicated in families with a history of early onset cancer but with no other unique features. Close linkage of disease to anonymous microsatellite markers on chromosome 2 was demonstrated in two large kindreds. The pairwise lod scores for linkage to marker D2S123 in these kindreds were 6.39 and 1.45 at zero recombination, and multipoint linkage with flanking markers resulted in lod scores of 6.47 and 6.01. These results prove the existence of a genetically determined predisposition to colorectal cancer that has important ramifications for understanding and preventing this disease. 13 refs., 1 fig., 1 tab.

  10. A comprehensive analysis of the chorion locus in silkmoth

    PubMed Central

    Chen, Zhiwei; Nohata, Junko; Guo, Huizhen; Li, Shenglong; Liu, Jianqiu; Guo, Youbing; Yamamoto, Kimiko; Kadono-Okuda, Keiko; Liu, Chun; Arunkumar, Kallare P.; Nagaraju, Javaregowda; Zhang, Yan; Liu, Shiping; Labropoulou, Vassiliki; Swevers, Luc; Tsitoura, Panagiota; Iatrou, Kostas; Gopinathan, Karumathil P.; Goldsmith, Marian R.; Xia, Qingyou; Mita, Kazuei

    2015-01-01

    Despite more than 40 years of intense study, essential features of the silkmoth chorion (eggshell) are still not fully understood. To determine the precise structure of the chorion locus, we performed extensive EST analysis, constructed a bacterial artificial chromosome (BAC) contig, and obtained a continuous genomic sequence of 871,711 base pairs. We annotated 127 chorion genes in two segments interrupted by a 164 kb region with 5 non-chorion genes, orthologs of which were on chorion bearing scaffolds in 4 ditrysian families. Detailed transcriptome analysis revealed expression throughout choriogenesis of most chorion genes originally categorized as “middle”, and evidence for diverse regulatory mechanisms including cis-elements, alternative splicing and promoter utilization, and antisense RNA. Phylogenetic analysis revealed multigene family associations and faster evolution of early chorion genes and transcriptionally active pseudogenes. Proteomics analysis identified 99 chorion proteins in the eggshell and micropyle localization of 1 early and 6 Hc chorion proteins. PMID:26553298

  11. A comprehensive analysis of the chorion locus in silkmoth.

    PubMed

    Chen, Zhiwei; Nohata, Junko; Guo, Huizhen; Li, Shenglong; Liu, Jianqiu; Guo, Youbing; Yamamoto, Kimiko; Kadono-Okuda, Keiko; Liu, Chun; Arunkumar, Kallare P; Nagaraju, Javaregowda; Zhang, Yan; Liu, Shiping; Labropoulou, Vassiliki; Swevers, Luc; Tsitoura, Panagiota; Iatrou, Kostas; Gopinathan, Karumathil P; Goldsmith, Marian R; Xia, Qingyou; Mita, Kazuei

    2015-01-01

    Despite more than 40 years of intense study, essential features of the silkmoth chorion (eggshell) are still not fully understood. To determine the precise structure of the chorion locus, we performed extensive EST analysis, constructed a bacterial artificial chromosome (BAC) contig, and obtained a continuous genomic sequence of 871,711 base pairs. We annotated 127 chorion genes in two segments interrupted by a 164 kb region with 5 non-chorion genes, orthologs of which were on chorion bearing scaffolds in 4 ditrysian families. Detailed transcriptome analysis revealed expression throughout choriogenesis of most chorion genes originally categorized as "middle", and evidence for diverse regulatory mechanisms including cis-elements, alternative splicing and promoter utilization, and antisense RNA. Phylogenetic analysis revealed multigene family associations and faster evolution of early chorion genes and transcriptionally active pseudogenes. Proteomics analysis identified 99 chorion proteins in the eggshell and micropyle localization of 1 early and 6 Hc chorion proteins. PMID:26553298

  12. Quantitative trait locus for reading disability on chromosome 6

    SciTech Connect

    Cardon, L.R. |; Smith, S.D.; Kimberling, W.J.; Fulker, D.W.; DeFries, J.C.; Pennington, B.F.

    1994-10-14

    Interval mapping of data from two independent samples of sib pairs, at least one member of whom was reading disabled, revealed evidence for a quantitative trait locus (QTL) on chromosome 6. Results obtained from analyses of reading performance from 114 sib pairs genotyped for DNA markers localized the QTL to 6p21.3. Analyses of corresponding data from an independent sample of 50 dizygotic twin pairs provided evidence for linkage to the same region. In combination, the replicate samples yielded a x{sup 2} value of 16.73 (P = 0.0002). Examination of twin and kindred siblings with more extreme deficits in reading performance yielded even stronger evidence for a QTL (x{sup 2} = 27.35, P < 0.00001). The position of the QTL was narrowly defined with a 100:1 confidence interval to a 2-centimorgan region within the human leukocyte antigen complex. 23 refs., 4 figs.

  13. Genomic organization and transcriptional units at the myotonic dystrophy locus

    SciTech Connect

    Shaw, D.J.; Rundle, S.A.; Harley, H.G.; Crow, S.R.; Harper, P.S. ); McCurrach, M.; Sohn, R.; Thirion, J.P.; Buckler, A.J.; Housman, D.E.; Brook, J.D. ); Hamshere, M.G. )

    1993-12-01

    The genomic structure and apparently complete coding sequence of the myotonic dystrophy protein kinase gene have been determined. The gene contains 15 exons distributed over about 13 kb of genomic DNA. It codes for a protein of 624 amino acids with an N-terminal domain highly homologous to cAMP-dependent serine-threonine protein kinases, an intermediate domain with a high [alpha]-helical content and weak similarity to various filamentous proteins, and a hydrophobic C-terminal segment. Located in close proximity is a second gene, coding for a transcript of about 3 kb, that is homologous to the gene DMR-N9 in the corresponding mouse locus, but has no homologies to other known genes or proteins. Strong expression of the latter gene in brain suggests that it may have a role in the development of mental symptoms in severe cases of the disease. 23 refs., 5 figs., 1 tab.

  14. Organization of the cpe Locus in CPE-Positive Clostridium perfringens Type C and D Isolates

    PubMed Central

    Li, Jihong; Miyamoto, Kazuaki; Sayeed, Sameera; McClane, Bruce A.

    2010-01-01

    Clostridium perfringens enterotoxin (encoded by the cpe gene) contributes to several important human, and possibly veterinary, enteric diseases. The current study investigated whether cpe locus organization in type C or D isolates resembles one of the three (one chromosomal and two plasmid-borne) cpe loci commonly found amongst type A isolates. Multiplex PCR assays capable of detecting sequences in those type A cpe loci failed to amplify products from cpe-positive type C and D isolates, indicating these isolates possess different cpe locus arrangements. Therefore, restriction fragments containing the cpe gene were cloned and sequenced from two type C isolates and one type D isolate. The obtained cpe locus sequences were then used to construct an overlapping PCR assay to assess cpe locus diversity amongst other cpe-positive type C and D isolates. All seven surveyed cpe-positive type C isolates had a plasmid-borne cpe locus partially resembling the cpe locus of type A isolates carrying a chromosomal cpe gene. In contrast, all eight type D isolates shared the same plasmid-borne cpe locus, which differed substantially from the cpe locus present in other C. perfringens by containing two copies of an ORF with 67% identity to a transposase gene (COG4644) found in Tn1546, but not previously associated with the cpe gene. These results identify greater diversity amongst cpe locus organization than previously appreciated, providing new insights into cpe locus evolution. Finally, evidence for cpe gene mobilization was found for both type C and D isolates, which could explain their cpe plasmid diversity. PMID:20532170

  15. Two-Stage Two-Locus Models in Genome-Wide Association

    PubMed Central

    Evans, David M; Marchini, Jonathan; Morris, Andrew P; Cardon, Lon R

    2006-01-01

    Studies in model organisms suggest that epistasis may play an important role in the etiology of complex diseases and traits in humans. With the era of large-scale genome-wide association studies fast approaching, it is important to quantify whether it will be possible to detect interacting loci using realistic sample sizes in humans and to what extent undetected epistasis will adversely affect power to detect association when single-locus approaches are employed. We therefore investigated the power to detect association for an extensive range of two-locus quantitative trait models that incorporated varying degrees of epistasis. We compared the power to detect association using a single-locus model that ignored interaction effects, a full two-locus model that allowed for interactions, and, most important, two two-stage strategies whereby a subset of loci initially identified using single-locus tests were analyzed using the full two-locus model. Despite the penalty introduced by multiple testing, fitting the full two-locus model performed better than single-locus tests for many of the situations considered, particularly when compared with attempts to detect both individual loci. Using a two-stage strategy reduced the computational burden associated with performing an exhaustive two-locus search across the genome but was not as powerful as the exhaustive search when loci interacted. Two-stage approaches also increased the risk of missing interacting loci that contributed little effect at the margins. Based on our extensive simulations, our results suggest that an exhaustive search involving all pairwise combinations of markers across the genome might provide a useful complement to single-locus scans in identifying interacting loci that contribute to moderate proportions of the phenotypic variance. PMID:17002500

  16. Role of CTCF protein in regulating FMR1 locus transcription.

    PubMed

    Lanni, Stella; Goracci, Martina; Borrelli, Loredana; Mancano, Giorgia; Chiurazzi, Pietro; Moscato, Umberto; Ferrè, Fabrizio; Helmer-Citterich, Manuela; Tabolacci, Elisabetta; Neri, Giovanni

    2013-01-01

    Fragile X syndrome (FXS), the leading cause of inherited intellectual disability, is caused by epigenetic silencing of the FMR1 gene, through expansion and methylation of a CGG triplet repeat (methylated full mutation). An antisense transcript (FMR1-AS1), starting from both promoter and intron 2 of the FMR1 gene, was demonstrated in transcriptionally active alleles, but not in silent FXS alleles. Moreover, a DNA methylation boundary, which is lost in FXS, was recently identified upstream of the FMR1 gene. Several nuclear proteins bind to this region, like the insulator protein CTCF. Here we demonstrate for the first time that rare unmethylated full mutation (UFM) alleles present the same boundary described in wild type (WT) alleles and that CTCF binds to this region, as well as to the FMR1 gene promoter, exon 1 and intron 2 binding sites. Contrariwise, DNA methylation prevents CTCF binding to FXS alleles. Drug-induced CpGs demethylation does not restore this binding. CTCF knock-down experiments clearly established that CTCF does not act as insulator at the active FMR1 locus, despite the presence of a CGG expansion. CTCF depletion induces heterochromatinic histone configuration of the FMR1 locus and results in reduction of FMR1 transcription, which however is not accompanied by spreading of DNA methylation towards the FMR1 promoter. CTCF depletion is also associated with FMR1-AS1 mRNA reduction. Antisense RNA, like sense transcript, is upregulated in UFM and absent in FXS cells and its splicing is correlated to that of the FMR1-mRNA. We conclude that CTCF has a complex role in regulating FMR1 expression, probably through the organization of chromatin loops between sense/antisense transcriptional regulatory regions, as suggested by bioinformatics analysis. PMID:23874213

  17. Somatic cell genotoxicity at the glycophorin A locus in humans

    SciTech Connect

    Jensen, R.H.; Grant, S.G.; Langlois, R.G.; Bigbee, W.L.

    1990-12-28

    We have developed an assay for detecting variant erythrocytes that occur as a result of in vivo allele loss at the glycophorin A (GPA) locus on chromosome 4 in humans. This gene codes for an erythroid- specific cell surface glycoprotein, and with our assay we are able to detect rare variant erythrocytes that have lost expression of one of the two GPA alleles. Two distinctly different variant cell types are detected with this assay. One variant cell type (called N{O}) is hemizygous. Our assay also detects homozygous variant erythrocytes that have lost expression of the GPA(M) allele and express the GPA(N) allele at twice the heterozygous level. The results of this assay are an enumeration of the frequency of N{O} and NN variant cell types for each individual analyzed. These variant cell frequencies provide a measure of the amount of somatic cell genotoxicity that has occurred at the GPA locus. Such genotoxicity could be the result of (1) reactions of toxic chemicals to which the individual has been exposed, or (2) high energy radiation effects on erythroid precursor cells, or (3) errors in DNA replication or repair in these cells of the bone marrow. Thus, the GPA-based variant cell frequency can serve as a biodosimeter that indicates the amount of genotoxic exposure each individual has received. Because two very different kinds of variant cells are enumerated, different kinds of genotoxicity should be distinguishable. Results of the GPA somatic genotoxicity assay may also provide valuable information for cancer-risk estimation on each individual. 16 refs.

  18. Quantitative trait locus mapping of soybean maturity gene E5

    PubMed Central

    Dissanayaka, Auchithya; Rodriguez, Tito O.; Di, Shaokang; Yan, Fan; Githiri, Stephen M.; Rodas, Felipe Rojas; Abe, Jun; Takahashi, Ryoji

    2016-01-01

    Time to flowering and maturity in soybean is controlled by loci E1 to E5, and E7 to E9. These loci were assigned to molecular linkage groups (MLGs) except for E5. This study was conducted to map the E5 locus using F2 populations expected to segregate for E5. F2 populations were subjected to quantitative trait locus (QTL) analysis for days to flowering (DF) and maturity (DM). In Harosoy-E5 × Clark-e2 population, QTLs for DF and DM were found at a similar position with E2. In Harosoy × Clark-e2E5 population, QTLs for DF and DM were found in MLG D1a and B1, respectively. In Harosoy-E5Dt2 × Clark-e2 population, a QTL for DF was found in MLG B1. Thus, results from these populations were not fully consistent, and no candidate QTL for E5 was found. In Harosoy × PI 80837 population, from which E5 was originally identified, QTLs corresponding to E1 and E3 were found, but none for E5 existed. Harosoy and PI 80837 had the e2-ns allele whereas Harosoy-E5 had the E2-dl allele. The E2-dl allele of Harosoy-E5 may have been generated by outcrossing and may be responsible for the lateness of Harosoy-E5. We conclude that a unique E5 gene may not exist. PMID:27436951

  19. Structure and genotypic plasticity of the Campylobacter fetus sap locus.

    PubMed

    Tu, Zheng-Chao; Wassenaar, Trudy M; Thompson, Stuart A; Blaser, Martin J

    2003-05-01

    The Campylobacter fetus surface layer proteins (SLPs), encoded by five to nine sapA homologues, are major virulence factors. To characterize the sapA homologues further, a 65.9 kb C. fetus genomic region encompassing the sap locus from wild-type strain 23D was completely sequenced and analysed; 44 predicted open reading frames (ORFs) were recognized. The 53.8 kb sap locus contained eight complete and one partial sapA homologues, varying from 2769 to 3879 bp, sharing conserved 553-2622 bp 5' regions, with partial sharing of 5' and 3' non-coding regions. All eight sapA homologues were expressed in Escherichia coli as antigenic proteins and reattached to the surface of SLP- strain 23B, indicating their conserved function. Analysis of the sap homologues indicated three phylogenetic groups. Promoter-specific polymerase chain reactions (PCRs) and sapA homologue-specific reverse transcription (RT)-PCRs showed that the unique sapA promoter can potentially express all eight sapA homologues. Reciprocal DNA recombination based on the 5' conserved regions can involve each of the eight sapA homologues, with frequencies from 10(-1) to 10(-3). Intragenic recombination between sapA7 and sapAp8, mediated by their conserved regions with a 10(-1)-10(-2) frequency, allows the formation of new sap homologues. As divergent SLP C-termini possess multiple antigenic sites, their reciprocal recombination behind the unique sap promoter leads to continuing antigenic variation. PMID:12694614

  20. Gsα activity is reduced in erythrocyte membranes of patients with psedohypoparathyroidism due to epigenetic alterations at the GNAS locus.

    PubMed

    Zazo, Celia; Thiele, Susanne; Martín, Cesar; Fernandez-Rebollo, Eduardo; Martinez-Indart, Lorea; Werner, Ralf; Garin, Intza; Hiort, Olaf; Perez de Nanclares, Guiomar

    2011-08-01

    In pseudohypoparathyroidism (PHP), PTH resistance results from impairment of signal transduction of G protein-coupled receptors caused by a deficiency of the Gsα-cAMP signaling cascade due to diminished Gsα activity in maternally imprinted tissues. In PHP-Ia, inactivating mutations of the GNAS gene lead to haploinsufficiency in some tissues with biallelic expression, so in addition to PHP, Albright's hereditary osteodystrophy (AHO) is also present. In PHP-Ib, caused by methylation defects at the GNAS locus, diminished Gsα activity was thought to be limited to maternally imprinted tissues, such as the renal proximal tubule and the thyroid, leading to a lack of AHO. Recently, we demonstrated methylation defects in patients with AHO signs, indicating a connection between epigenetic changes and AHO. Our objective was to determine Gsα activity in erythrocyte membranes in patients with epigenetic defects at the GNAS locus compared to normal controls and patients with inactivating GNAS mutations. Gsα activity and expression, mutation of the GNAS locus, and methylation status were studied in patients with PHP and mild signs of AHO (PHP-Ia: 12; PHP-Ib: 17, of which 8 had some features of AHO). Then, we statistically compared the Gsα activity of the different PHP subtypes. Patients with methylation defects at the GNAS locus show a significant decrease in erythrocyte Gsα activity compared to normal controls (PHP-Ib versus controls, p < .001). This was significantly lower in patients with AHO signs (PHP-Ib + mild-AHO versus PHP-Ib, p < .05). Our research shows that PHP-Ia and PHP-Ib classification is not only overlapped genetically, as reported, but also in terms of Gsα activity. Reduced expression of GNAS due to methylation defects could downregulate Gsα activity in other tissues beyond those described and could also be causative of AHO. PMID:21351142

  1. Does Wheat Genetically Modified for Disease Resistance Affect Root-Colonizing Pseudomonads and Arbuscular Mycorrhizal Fungi?

    PubMed Central

    Foetzki, Andrea; Luginbühl, Carolin; Winzeler, Michael; Kneubühler, Yvan; Matasci, Caterina; Mascher-Frutschi, Fabio; Kalinina, Olena; Boller, Thomas; Keel, Christoph; Maurhofer, Monika

    2013-01-01

    This study aimed to evaluate the impact of genetically modified (GM) wheat with introduced pm3b mildew resistance transgene, on two types of root-colonizing microorganisms, namely pseudomonads and arbuscular mycorrhizal fungi (AMF). Our investigations were carried out in field trials over three field seasons and at two locations. Serial dilution in selective King's B medium and microscopy were used to assess the abundance of cultivable pseudomonads and AMF, respectively. We developed a denaturing gradient gel electrophoresis (DGGE) method to characterize the diversity of the pqqC gene, which is involved in Pseudomonas phosphate solubilization. A major result was that in the first field season Pseudomonas abundances and diversity on roots of GM pm3b lines, but also on non-GM sister lines were different from those of the parental lines and conventional wheat cultivars. This indicates a strong effect of the procedures by which these plants were created, as GM and sister lines were generated via tissue cultures and propagated in the greenhouse. Moreover, Pseudomonas population sizes and DGGE profiles varied considerably between individual GM lines with different genomic locations of the pm3b transgene. At individual time points, differences in Pseudomonas and AMF accumulation between GM and control lines were detected, but they were not consistent and much less pronounced than differences detected between young and old plants, different conventional wheat cultivars or at different locations and field seasons. Thus, we conclude that impacts of GM wheat on plant-beneficial root-colonizing microorganisms are minor and not of ecological importance. The cultivation-independent pqqC-DGGE approach proved to be a useful tool for monitoring the dynamics of Pseudomonas populations in a wheat field and even sensitive enough for detecting population responses to altered plant physiology. PMID:23372672

  2. Serotypes, Antibiotic Susceptibilities, and Multi-Locus Sequence Type Profiles of Streptococcus agalactiae Isolates Circulating in Beijing, China

    PubMed Central

    Ma, Xiu-hua; Song, Feng-li; Fan, Ling; Guo, Cui-mei; Shi, Wei; Yu, Sang-jie; Yao, Kai-hu; Yang, Yong-hong

    2015-01-01

    Background To investigate the serotypes, antibiotic susceptibilities, and multi-locus sequence type (MLST) profiles of Streptococcus agalactiae (S. agalactiae) in Beijing to provide references for the prevention and treatment of S. agalactiae infections. Methods All isolates were identified using the CAMP test and the latex-agglutination assay and serotyped using a Strep-B-Latex kit, after which they were assessed for antibiotic susceptibility, macrolide-resistance genes, and MLST profiles. Results In total, 56 S. agalactiae isolates were identified in 863 pregnant women (6.5%). Serotypes Ia, Ib, II, III, and V were identified, among which types III (32.1%), Ia (17.9%), Ib (16.1%), and V (14.3%) were the predominant serotypes. All isolates were susceptible to penicillin and ceftriaxone. The nonsusceptiblity rates measured for erythromycin, clarithromycin, azithromycin, telithromycin, clindamycin, tetracycline, and levofloxacin were 85.7%, 92.9%, 98.2%, 30.4%, 73.2%, 91%, and 39.3%, respectively. We identified 14 sequence types (STs) for the 56 isolates, among which ST19 (30.4%) was predominant. The rate of fluoroquinolone resistance was higher in serotype III than in the other serotypes. Among the 44 erythromycin-resistant isolates, 32 (72.7%) carried ermB. Conclusion S. agalactiae isolates of the serotypes Ia, Ib, III, and V are common in Beijing. Among the S. agalactiae isolates, the macrolide and clindamycin resistance rates are extremely high. Most of the erythromycin-resistant isolates carry ermB. PMID:25781346

  3. Localization by restriction fragment length polymorphism mapping in potato of a major dominant gene conferring resistance to the potato cyst nematode Globodera rostochiensis.

    PubMed

    Barone, A; Ritter, E; Schachtschabel, U; Debener, T; Salamini, F; Gebhardt, C

    1990-11-01

    A major dominant locus conferring resistance against several pathotypes of the root cyst nematode Globodera rostochiensis was mapped on the linkage map of potato using restriction fragment length polymorphism (RFLP) markers. The assessment of resistance versus susceptibility of the plants in the experimental population considered was based on an in vivo (pot) and an in vitro (petri dish) test. By linkage to nine RFLP markers the resistance locus Gro1 was assigned to the potato linkage group IX which is homologous to the tomato linkage group 7. Deviations from the additivity of recombination frequencies between Gro1 and its neighbouring markers in the pot test led to the detection of a few phenotypic misclassifications of small plants with poor root systems that limited the observation of cysts on susceptible roots. Pooled data from both tests provided better estimates of recombination frequencies in the linkage interval defined by the markers flanking the resistance locus. PMID:1980523

  4. Resistant Hypertension.

    PubMed

    Doroszko, Adrian; Janus, Agnieszka; Szahidewicz-Krupska, Ewa; Mazur, Grzegorz; Derkacz, Arkadiusz

    2016-01-01

    Resistant hypertension is a severe medical condition which is estimated to appear in 9-18% of hypertensive patients. Due to higher cardiovascular risk, this disorder requires special diagnosis and treatment. The heterogeneous etiology, risk factors and comorbidities of resistant hypertension stand in need of sophisticated evaluation to confirm the diagnosis and select the best therapeutic options, which should consider lifestyle modifications as well as pharmacological and interventional treatment. After having excluded pseudohypertension, inappropriate blood pressure measurement and control as well as the white coat effect, suspicion of resistant hypertension requires an analysis of drugs which the hypertensive patient is treated with. According to one definition - ineffective treatment with 3 or more antihypertensive drugs including diuretics makes it possible to diagnose resistant hypertension. A multidrug therapy including angiotensin - converting enzyme inhibitors, angiotensin II receptor blockers, beta blockers, diuretics, long-acting calcium channel blockers and mineralocorticoid receptor antagonists has been demonstrated to be effective in resistant hypertension treatment. Nevertheless, optional, innovative therapies, e.g. a renal denervation or baroreflex activation, may create a novel pathway of blood pressure lowering procedures. The right diagnosis of this disease needs to eliminate the secondary causes of resistant hypertension e.g. obstructive sleep apnea, atherosclerosis and renal or hormonal disorders. This paper briefly summarizes the identification of the causes of resistant hypertension and therapeutic strategies, which may contribute to the proper diagnosis and an improvement of the long term management of resistant hypertension. PMID:26935512

  5. Aphid resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Testing and selecting for Russian wheat aphid (RWA) and greenbug resistance in WIT breeding lines continued this year. Several excellent lines with high levels of resistance advanced through the cultivar development process. Single plant selections from six experimental lines were retested to conf...

  6. Analysis of the Lr34/Yr18 rust resistance region in wheat germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An insertion/deletion size variant located at the csLV34 locus on chromosome 7D within an intron sequence of a sulphate transporter-like gene tightly linked to the Lr34/Yr18 dual rust resistance was used to examine a global collection of wheat cultivars, landraces and D genome containing diploid and...

  7. Single nucleotide polymorphism in wheat chromosome region harboring Fhb1 for Fusarium head blight resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium head blight (FHB) is a destructive disease that reduces wheat grain yield and quality. To date, the quantitative trait locus on 3BS (Fhb1) from Sumai 3 has shown the largest effect on FHB resistance. Single nucleotide polymorphism (SNP) is the most common form of genetic variation and suita...

  8. The X-linked F cell production locus: Genetic mapping and role in fetal hemoglobin production

    SciTech Connect

    Chang, Y.C.; Smith, K.D.; Moore, R.D.

    1994-09-01

    Postnatal fetal hemoglobin (Hb F) production is confined to a subset of erythocytes termed F-cells. There is a 10-20 fold variation in F-cell production in sickle cell disease (SCD) and normal individuals. Most of the variation in F-cell production has been attributed to a diallelic (High, Low) X-linked gene, the F-cell production (FCP) locus that we recently mapped to Xp22.2-22.3 (LOD=4.56, theta=0.04). Using multiple regression analysis in 262 Jamaican SCD patients we determined the relative contribution of the FCP locus and other variables previously associated with variation in Hb F level (gender, age, beta-globin haplotypes, number of alpha-globin genes and the FCP locus phenotypes). When the FCP locus is in the regression model, the FCP locus alone accounts for approximately 40% of the variation in Hb F level while the contribution of age, alpha-globin gene number, and beta-globin haplotypes was insignificant. When individuals with High FCP allele are removed from the analysis, the beta globin haplotype now contribute to >10% of the Hb F variation. We conclude that the X-linked FCP locus is the major determinant of all known variables in Hb F production. Using 4 highly polymorphic dinucleotide repeat markers that we identified from cosmids in Xp22.2-22.3, have localized the FCP locus to a 1 Mb minimal candidate region between DXS143 and DXS410.

  9. Association study between the TNXB locus and schizophrenia in a Japanese population.

    PubMed

    Tochigi, Mamoru; Zhang, Xuan; Ohashi, Jun; Hibino, Hiroyuki; Otowa, Takeshi; Rogers, Mark; Kato, Tadafumi; Okazaki, Yuji; Kato, Nobumasa; Tokunaga, Katsushi; Sasaki, Tsukasa

    2007-04-01

    The chromosome 6p21-24 region, which contains the human leukocyte antigen (HLA) region, has been suggested as an important locus for a susceptibility gene for schizophrenia. Recently, a significant association between schizophrenia and the TNXB locus, located immediately telomeric of the NOTCH4 locus in the HLA region, was observed. Few studies have further investigated the region in schizophrenia. In the present study, we investigated the region in a Japanese population. Subjects included 241 patients with schizophrenia and 290 controls. Twenty-six single nucleotide polymorphisms (SNPs) and the corresponding haplotypes were analyzed. As a result, exactly the same SNPs in the TNXB locus (rs1009382 and rs204887) as in the previous study were associated with schizophrenia (P = 0.034 and 0.034, respectively, uncorrected). A SNP (rs2071287) in the NOTCH4 locus and haplotype around it were also suggested to associate with the disease, consistent with another previous study (P = 0.041 and permutation P = 0.024, respectively, uncorrected). Although these associations became insignificant after Bonferroni correction, the findings might provide support for the association of the TNXB locus or its adjacent region of the NOTCH4 locus with schizophrenia. PMID:17192952

  10. Prevalence of Porphyromonas gingivalis Four rag Locus Genotypes in Patients of Orthodontic Gingivitis and Periodontitis

    PubMed Central

    Liu, Yi; Zhang, Yujie; Wang, Lili; Guo, Yang; Xiao, Shuiqing

    2013-01-01

    Porphyromonas gingivalis is considered as a major etiological agent in periodontal diseases and implied to result in gingival inflammation under orthodontic appliance. rag locus is a pathogenicity island found in Porphyromonas gingivalis. Four rag locus variants are different in pathogenicity of Porphyromonas gingivalis. Moreover, there are different racial and geographic differences in distribution of rag locus genotypes. In this study, we assessed the prevalence of Porphyromonas gingivalis and rag locus genotypes in 102 gingival crevicular fluid samples from 57 cases of gingivitis patients with orthodontic appliances, 25 cases of periodontitis patients and 20 cases of periodontally healthy people through a 16S rRNA-based PCR and a multiplex PCR. The correlations between Porphyromona.gingivalis/rag locus and clinical indices were analyzed. The prevalence of Porphyromonas gingivalis and rag locus genes in periodontitis group was the highest among three groups and higher in orthodontic gingivitis than healthy people (p<0.01). An obviously positive correlation was observed between the prevalence of Porphyromonas gingivalis/rag locus and gingival index. rag-3 and rag-4 were the predominant genotypes in the patients of orthodontic gingivitis and mild-to-moderate periodontitis in Shandong. Porphyromonas.gingivalis carrying rag-1 has the strong virulence and could be associated with severe periodontitis. PMID:23593379

  11. Prevalence of Porphyromonas gingivalis four rag locus genotypes in patients of orthodontic gingivitis and periodontitis.

    PubMed

    Liu, Yi; Zhang, Yujie; Wang, Lili; Guo, Yang; Xiao, Shuiqing

    2013-01-01

    Porphyromonas gingivalis is considered as a major etiological agent in periodontal diseases and implied to result in gingival inflammation under orthodontic appliance. rag locus is a pathogenicity island found in Porphyromonas gingivalis. Four rag locus variants are different in pathogenicity of Porphyromonas gingivalis. Moreover, there are different racial and geographic differences in distribution of rag locus genotypes. In this study, we assessed the prevalence of Porphyromonas gingivalis and rag locus genotypes in 102 gingival crevicular fluid samples from 57 cases of gingivitis patients with orthodontic appliances, 25 cases of periodontitis patients and 20 cases of periodontally healthy people through a 16S rRNA-based PCR and a multiplex PCR. The correlations between Porphyromona.gingivalis/rag locus and clinical indices were analyzed. The prevalence of Porphyromonas gingivalis and rag locus genes in periodontitis group was the highest among three groups and higher in orthodontic gingivitis than healthy people (p<0.01). An obviously positive correlation was observed between the prevalence of Porphyromonas gingivalis/rag locus and gingival index. rag-3 and rag-4 were the predominant genotypes in the patients of orthodontic gingivitis and mild-to-moderate periodontitis in Shandong. Porphyromonas.gingivalis carrying rag-1 has the strong virulence and could be associated with severe periodontitis. PMID:23593379

  12. Centromere anatomy in the multidrug-resistant pathogen Enterococcus faecium

    PubMed Central

    Derome, Andrew; Hoischen, Christian; Bussiek, Malte; Grady, Ruth; Adamczyk, Malgorzata; Kędzierska, Barbara; Diekmann, Stephan; Barillà, Daniela; Hayes, Finbarr

    2008-01-01

    Multidrug-resistant variants of the opportunistic human pathogen Enterococcus have recently emerged as leading agents of nosocomial infection. The acquisition of plasmid-borne resistance genes is a driving force in antibiotic-resistance evolution in enterococci. The segregation locus of a high-level gentamicin-resistance plasmid, pGENT, in Enterococcus faecium was identified and dissected. This locus includes overlapping genes encoding PrgP, a member of the ParA superfamily of segregation proteins, and PrgO, a site-specific DNA binding homodimer that recognizes the cenE centromere upstream of prgPO. The centromere has a distinctive organization comprising three subsites, CESII separates CESI and CESIII, each of which harbors seven TATA boxes spaced by half-helical turns. PrgO independently binds both CESI and CESIII, but with different affinities. The topography of the complex was probed by atomic force microscopy, revealing discrete PrgO foci positioned asymmetrically at the CESI and CESIII subsites. Bending analysis demonstrated that cenE is intrinsically curved. The organization of the cenE site and of certain other plasmid centromeres mirrors that of yeast centromeres, which may reflect a common architectural requirement during assembly of the mitotic apparatus in yeast and bacteria. Moreover, segregation modules homologous to that of pGENT are widely disseminated on vancomycin and other resistance plasmids in enterococci. An improved understanding of segrosome assembly may highlight new interventions geared toward combating antibiotic resistance in these insidious pathogens. PMID:18245388

  13. Iso-lines and Inbred-lines Confirmed Loci that Underlie Resistance from Cultivar 'Hartwig' to Three Soybean Cyst Nematode Populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean [Glycine max (L.) Merr.] cultivars vary in their resistance to different populations of the soybean cyst nematode (SCN), Heterodera glycines. Populations are classified into groups called HG Types. The rhg1 locus on linkage group G underlying resistance to HG Type 0 was necessary for resista...

  14. Gene-specific markers for the wheat gene Lr34/Yr18/Pm38 which confers resistance to multiple fungal pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The locus Lr34/Yr18/Pm38 confers partial and durable resistance against the devastating fungal pathogens leaf rust, stripe rust, and powdery mildew. In previous studies, this broad-spectrum resistance was shown to be controlled by a single gene which encodes a putative ATP-binding cassette transport...

  15. Intragenic recombination in the CSR1 locus of Arabidopsis.

    PubMed

    Mourad, G; Haughn, G; King, J

    1994-04-01

    Four classes of herbicides are known to inhibit plant acetolactate synthase (ALS). In Arabidopsis, ALS is encoded by a single gene, CSR1. The dominant csr1-1 allele encodes an ALS resistant to chlorsulfuron and triazolopyrimidine sulfonamide while the dominant csr1-2 allele encodes an ALS resistant to imazapyr and pyrimidyl-oxy-benzoate. The molecular distance between the point mutations in csr1-1 and csr1-2 is 1369 bp. Here we used multiherbicide resistance as a stringent selection to measure the intragenic recombination frequency between these two point mutations. We found this frequency to be 0.008 +/- 0.0028. The recombinant multiherbicide-resistant allele, csr1-4, provides an ideal marker for plant genetic transformation. PMID:8177214

  16. [Illness concepts of children. Validation of a modified locus of control test in illness and health].

    PubMed

    Schmidt, A; Altmann-Herz, U

    1992-12-01

    We investigated the health and illness concepts of 53 healthy children aged 8 to 14 years using a modified illness and health locus of control scale (KKG, Lohaus and Schmitt, 1989) with the scales internal, external-p (powerful others) and external-c (chance). A comparison of the results with those on self-esteem (FSK 4-6), anxiety (CMAS-R) and hopelessness (HSC) scales showed a decrease in externality, but not an increase in internality, with increasing age and a correlation between self-confidence and a more internal locus of control. The influence of children's health locus of control on treatment compliance is discussed. PMID:1288033

  17. Evidence for a third genetic locus for autosomal dominant polycystic kidney disease

    SciTech Connect

    Daoust, M.C.; Bichet, D.G.; Reynolds, D.M.

    1995-02-10

    Autosomal dominant polycystic kidney disease (ADPKD) is a genetically heterogeneous disease with loci on chromosomes 16p and 4q. It has a moderately high spontaneous mutation rate, although the relative frequency of such mutations at each gene locus is unknown. In studying genetic heterogeneity in the French-Canadian population, we identified a family in which a classical clinical presentation of ADPKD resulted from a mutation at a locus genetically distinct from either of the previously described loci for this disease. This suggests the existence of a third genetic locus for ADPKD. 21 refs., 1 fig., 1 tab.

  18. Test illuminant location with respect to the Planckian locus affects chromaticity shifts of real Munsell chips.

    PubMed

    Daugirdiene, A; Kulikowski, J J; Murray, I J; Kelly, J M F

    2016-03-01

    The asymmetric sequential color-matching technique was used to determine the shifts in chromaticity of real Munsell chips induced by four test illuminants. The reference illuminant was C. Illuminants green (G) and purple (P) induced shifts orthogonal to the Planckian locus, while illuminants S and A induced shifts along the Planckian locus. Vectors describing the shifts induced by A and S were quantitatively and qualitatively different from those due to G and P. The data suggest that physiological factors, influenced by the proximity of the Planckian locus, affect chromatic constancy under nonsimulated viewing conditions. PMID:26974944

  19. Molecular characterization of a region of DNA associated with mutations at the agouti locus in the mouse.

    PubMed Central

    Bultman, S J; Russell, L B; Gutierrez-Espeleta, G A; Woychik, R P

    1991-01-01

    Molecular characterization of a radiation-induced agouti (a)-locus mutation has resulted in the isolation of a segment of DNA that maps at or near the a locus on chromosome 2 in the mouse. This region of DNA is deleted in several radiation- or chemical-induced homozygous-lethal a-locus mutations and is associated with specific DNA structural alterations in two viable a-locus mutations. We propose that DNA probes from this region of chromosome 2 will be useful for ultimately characterizing the individual gene or genes associated with a-locus function. Images PMID:1896452

  20. A Novel Route Controlling Begomovirus Resistance by the Messenger RNA Surveillance Factor Pelota

    PubMed Central

    Lapidot, Moshe; Karniel, Uri; Gelbart, Dana; Fogel, Doron; Evenor, Dalia; Kutsher, Yaarit; Makhbash, Zion; Nahon, Sahadia; Shlomo, Haviva; Chen, Lea; Reuveni, Moshe; Levin, Ilan

    2015-01-01

    Tomato yellow leaf curl virus (TYLCV) is a devastating disease of tomato (Solanum lycopersicum) that can be effectively controlled by the deployment of resistant cultivars. The TYLCV-resistant line TY172 carries a major recessive locus for TYLCV resistance, designated ty-5, on chromosome 4. In this study, the association between 27 polymorphic DNA markers, spanning the ty-5 locus, and the resistance characteristics of individual plants inoculated with TYLCV in 51 segregating recombinant populations were analyzed. These analyses localized ty-5 into a 425 bp region containing two transversions: one in the first exon of a gene encoding the tomato homolog of the messenger RNA surveillance factor Pelota (Pelo), and a second in its proximal promoter. Analyses of susceptible and resistant lines revealed that the relative transcript level of the gene remained unchanged, regardless of whether the plants were infected with TYLCV or not. This suggests that the polymorphism discovered in the coding region of the gene controls the resistance. Silencing of Pelo in a susceptible line rendered the transgenic plants highly resistant, while in the resistant line TY172 had no effect on symptom development. In addition, over-expression of the susceptible allele of the gene in the resistant TY172 line rendered it susceptible, while over-expression of the resistant allele in susceptible plants had no effect. These results confirm that Pelo is the gene controlling resistance at the ty-5 locus. Pelo, implicated in the ribosome recycling-phase of protein synthesis, offers an alternative route to promote resistance to TYLCV and other viruses. PMID:26448569

  1. Resisting HRD's Resistance to Diversity

    ERIC Educational Resources Information Center

    Bierema, Laura L.

    2010-01-01

    Purpose: The purpose of this paper is to empirically illustrate how human resource development (HRD) resists and omits issues of diversity in academic programs, textbooks, and research; analyze the research on HRD and diversity over a ten-year period; discuss HRD's resistance to diversity; and offer some recommendations for a more authentic…

  2. Resistivity analysis

    SciTech Connect

    Bruce, Michael R.; Bruce, Victoria J.; Ring, Rosalinda M.; Cole, Edward Jr. I.; Hawkins, Charles F.; Tangyungong, Paiboon

    2006-06-13

    According to an example embodiment of the present invention a semiconductor die having a resistive electrical connection is analyzed. Heat is directed to the die as the die is undergoing a state-changing operation to cause a failure due to suspect circuitry. The die is monitored, and a circuit path that electrically changes in response to the heat is detected and used to detect that a particular portion therein of the circuit is resistive. In this manner, the detection and localization of a semiconductor die defect that includes a resistive portion of a circuit path is enhanced.

  3. High chlorpyrifos resistance in Culex pipiens mosquitoes: strong synergy between resistance genes.

    PubMed

    Alout, H; Labbé, P; Berthomieu, A; Makoundou, P; Fort, P; Pasteur, N; Weill, M

    2016-02-01

    We investigated the genetic determinism of high chlorpyrifos resistance (HCR), a phenotype first described in 1999 in Culex pipiens mosquitoes surviving chlorpyrifos doses ⩾1 mg l(-1) and more recently found in field samples from Tunisia, Israel or Indian Ocean islands. Through chlorpyrifos selection, we selected several HCR strains that displayed over 10 000-fold resistance. All strains were homozygous for resistant alleles at two main loci: the ace-1 gene, with the resistant ace-1(R) allele expressing the insensitive G119S acetylcholinesterase, and a resistant allele of an unknown gene (named T) linked to the sex and ace-2 genes. We constructed a strain carrying only the T-resistant allele and studied its resistance characteristics. By crossing this strain with strains harboring different alleles at the ace-1 locus, we showed that the resistant ace-1(R) and the T alleles act in strong synergy, as they elicited a resistance 100 times higher than expected from a simple multiplicative effect. This effect was specific to chlorpyrifos and parathion and was not affected by synergists. We also examined how HCR was expressed in strains carrying other ace-1-resistant alleles, such as ace-1(V) or the duplicated ace-1(D) allele, currently spreading worldwide. We identified two major parameters that influenced the level of resistance: the number and the nature of the ace-1-resistant alleles and the number of T alleles. Our data fit a model that predicts that the T allele acts by decreasing chlorpyrifos concentration in the compartment targeted in insects. PMID:26463842

  4. The plasmacytoma resistance gene, Pctr2, delays the onset of tumorigenesis and resides in the telomeric region of chromosome 4.

    PubMed

    Mock, B A; Hartley, J; Le Tissier, P; Wax, J S; Potter, M

    1997-11-15

    Mouse plasmacytomas share pathogenetic features in common with both multiple myeloma and Burkitt's lymphoma in humans. Susceptibility to plasmacytoma induction by intraperitoneal pristane in mice is controlled by multiple genes. At least two of these genes reside on mouse chromosome 4 in regions of the genome sharing linkage homology with human chromosomes 9p21, 1p32, and 1p36. A series of congenic strains recombinant for regions of mouse chromosome 4 in the vicinity of the Pctr2 predisposition locus were created and typed for their tumor susceptibility/resistance phenotypes. These strains were derived by introgressively backcrossing alleles from resistant DBA/2 mice onto the susceptible BALB/cAnPt background. Six resistant and two susceptible strains were allelotyped for 10 genes and 49 random DNA markers to identify the smallest region of overlap in the resistant strains. These studies have determined that the Pctr2 locus resides in either a 500-kb interval proximal to Nppa, or in a 1- to 2-centiMorgan (cM) interval distal to Nppa. In these congenic strain analyses, the Nppa and Fv1 loci, in addition to genes within about 1 cM of these loci, have been excluded as candidates for the Pctr2 locus. A relevant locus that may reside in this interval is Rep2; it is associated with the efficiency of repairing X-ray induced DNA damage sustained during the G2 phase of the mitotic cycle. The Pctr2 locus acts in a codominant fashion. F1 hybrids between resistant and susceptible congenic strains exhibit a reduced tumor incidence and a significant delay in the onset of tumorigenesis. Identification and eventual cloning of the Pctr2 locus may assist in the identification of genes involved in many types of cancer showing aberrations in human chromosome 1p36. PMID:9354679

  5. Antimicrobial Resistance

    MedlinePlus

    ... and health professionals can play their part; rewarding innovation and development of new treatment options and other ... and industry can help tackle resistance by: fostering innovation and research and development of new vaccines, diagnostics, ...

  6. Antimicrobial Resistance

    MedlinePlus

    ... antibiotic are known as methicillin-resistant S. aureus or MRSA. Antibiotics and other antimicrobial drugs first became widely ... factors for infection are known as community-associated MRSA (CA-MRSA). Recently, several cases overseas and in ...

  7. Determinants that increase the serum resistance of Escherichia coli.

    PubMed Central

    Taylor, P W; Robinson, M K

    1980-01-01

    The rfb locus, determining biosynthesis of O8-specific lipopolysaccharide side chains, was transferred to a rough mutant of Escherichia coli; recombinants producing a complete lipopolysaccharide were more resistant to the complement-mediated bactericidal action of human serum than the rough recipient. Inheritance of the his-linked genes for K27 antigen production did not alter the response to serum. The serum resistance of strains carrying O8 side chains, but not of strains with incomplete lipopolysaccharides, was further increased by inheritance of plasmids R1 and NR1.20 PMID:6995340

  8. Mapping a disease locus by allelic association

    PubMed Central

    Collins, A.; Morton, N. E.

    1998-01-01

    Allelic association provides a means to map disease genes that, in a dense map of polymorphic markers, has considerably higher resolution than linkage methods. We describe here a composite likelihood estimate of location for a disease gene against a high-resolution marker map by using allele frequencies at linked loci. Data may be family-based, as in the transmission disequilibrium test, or from a case-control study. χ2 tests, logarithm of odds, standard errors, and information weights are provided. The method is illustrated by analysis of published cystic fibrosis haplotypes, in which ΔF508 is more accurately localized than by other association studies. This differs from current approaches by adopting a more general Malecot model for isolation by distance, where distance here is between marker and disease locus, allowance for errors in the map and model, and freedom from assumptions about demography, systematic pressures, and the ratio of physical to genetic distance. When these assumptions are introduced the number of generations since the original mutation may be estimated, but this is not required to determine location and its standard error, so that evidence from allelic association may be efficiently combined with linkage evidence to identify a region for positional cloning of a disease gene. PMID:9465087

  9. Bayesian quantitative trait locus mapping using inferred haplotypes.

    PubMed

    Durrant, Caroline; Mott, Richard

    2010-03-01

    We describe a fast hierarchical Bayesian method for mapping quantitative trait loci by haplotype-based association, applicable when haplotypes are not observed directly but are inferred from multiple marker genotypes. The method avoids the use of a Monte Carlo Markov chain by employing priors for which the likelihood factorizes completely. It is parameterized by a single hyperparameter, the fraction of variance explained by the quantitative trait locus, compared to the frequentist fixed-effects model, which requires a parameter for the phenotypic effect of each combination of haplotypes; nevertheless it still provides estimates of haplotype effects. We use simulation to show that the method matches the power of the frequentist regression model and, when the haplotypes are inferred, exceeds it for small QTL effect sizes. The Bayesian estimates of the haplotype effects are more accurate than the frequentist estimates, for both known and inferred haplotypes, which indicates that this advantage is independent of the effect of uncertainty in haplotype inference and will hold in comparison with frequentist methods in general. We apply the method to data from a panel of recombinant inbred lines of Arabidopsis thaliana, descended from 19 inbred founders. PMID:20048050

  10. Locus of the intensity effect in simple reaction time tasks.

    PubMed

    Jaśkowski, Piotr; Kurczewska, Marta; Nowik, Agnieszka; van der Lubbe, Rob H J; Verleger, Rolf

    2007-11-01

    Evidence is still inconclusive regarding the locus of the stimulus intensity effect on information processing in reaction tasks. Miller, Ulrich, and Rinkenauer (1999) addressed this question by assessing the intensity effect on stimulus- and response-locked lateralized readiness potentials (LRPs) as indices of the sensory and motor parts of reaction time (RT). In the case of visual stimuli, they observed that application of brighter stimuli resulted in a shortening of RT and stimulus-locked LRP (S-LRP), but not of response-locked LRP (R-LRP). The results for auditory stimuli, however, were unclear. In spite of a clear RT reduction due to increased loudness, neither S-LRP nor R-LRP onset was affected. A reason for this failure might have been a relatively small range of intensity variation and the type of task. To check for this possibility, we performed three experiments in which broader ranges of stimulus intensities and simple, rather than choice, response tasks were used. Although the intensity effect on the R-LRP was negligible, S-LRP followed RT changes, irrespective of stimulus modality. These findings support the conclusion that stimulus intensity exerts its effect before the start of motoric processes. Finally, S-LRP and R-LRP findings are discussed within a broader information-processing perspective to check the validity of the claim that S-LRP and R-LRP can, indeed, be considered as pure estimates of the duration of sensory and motor processes. PMID:18078225

  11. Paramutation alters regulatory control of the maize pl locus.

    PubMed Central

    Hollick, J B; Patterson, G I; Asmundsson, I M; Chandler, V L

    2000-01-01

    The maize purple plant (pl) locus encodes a transcription factor required for anthocyanin pigment synthesis in vegetative and floral tissues. The strongly expressed Pl-Rhoades (Pl-Rh) allele is unstable, spontaneously changing to weaker expression states (Pl') at low frequencies and exclusively changing to Pl' in Pl'/Pl-Rh heterozygotes. The weakly expressed Pl' state is mitotically and meiotically stable, yet reversible. This type of allele-dependent, heritable alteration of gene control is called paramutation. Expression studies herein demonstrate that visible differences in anthocyanin pigment levels mirror pl RNA abundance and that pl paramutation is associated with reduced transcription of the pl gene. This transcriptional alteration is accompanied by acquisition of light-dependent regulation. Restriction endonuclease mapping indicates that these changes in pl gene regulation are not associated with detectable DNA alterations or with extensive changes in cytosine methylation patterns. Genetic tests show that Pl-Blotched (Pl-Bh), a structurally similar pl allele encoding an identical pl RNA and PL protein, does not participate in pl paramutation. This result suggests that if cis-acting sequences are required for pl paramutation they are distinct from the protein coding and immediately adjacent regions. A model is discussed in which pl paramutation results in heritable changes of chromatin structure that fundamentally alter regulatory interactions occurring during plant development. PMID:10747073

  12. Genome wide association scan for chronic periodontitis implicates novel locus

    PubMed Central

    2014-01-01

    Background There is evidence for a genetic contribution to chronic periodontitis. In this study, we conducted a genome wide association study among 866 participants of the University of Pittsburgh Dental Registry and DNA Repository, whose periodontal diagnosis ranged from healthy (N = 767) to severe chronic periodontitis (N = 99). Methods Genotypingi of over half-million single nucleotide polymorphisms was determined. Analyses were done twice, first in the complete dataset of all ethnicities, and second including only samples defined as self-reported Whites. From the top 100 results, twenty single nucleotide polymorphisms had consistent results in both analyses (borderline p-values ranging from 1E-05 to 1E-6) and were selected to be tested in two independent datasets derived from 1,460 individuals from Porto Alegre, and 359 from Rio de Janeiro, Brazil. Meta-analyses of the Single nucleotide polymorphisms showing a trend for association in the independent dataset were performed. Results The rs1477403 marker located on 16q22.3 showed suggestive association in the discovery phase and in the Porto Alegre dataset (p = 0.05). The meta-analysis suggested the less common allele decreases the risk of chronic periodontitis. Conclusions Our data offer a clear hypothesis to be independently tested regarding the contribution of the 16q22.3 locus to chronic periodontitis. PMID:25008200

  13. Locus of control patterns in headaches and chronic pain

    PubMed Central

    Cano-García, Francisco Javier; Rodríguez-Franco, Luis; López-Jiménez, Ana María

    2013-01-01

    BACKGROUND: Locus of control (LOC) is related to the impact of headaches and chronic pain; however, literature evidence regarding LOC is not always consistent. Several authors consider this to be due, in part, to the separate interpretation of LOC factors, during which the interaction among them is ignored. In 1982, Wallston and Wallston proposed eight possible LOC health patterns depending on whether the individual scored high or low in each of three dimensions. OBJECTIVE: To identify these LOC patterns in patients with headaches and chronic pain, and to validate them in terms of their association with a selection of the main pain indicators. METHODS: A total of 228 individuals were recruited at three public centres in Seville, Spain. Participants completed a semistructured clinical interview and several questionnaires assessing psychological variables related to pain. The main statistical analyses used were two-step cluster analysis and ANCOVA. RESULTS: The six-cluster solution was optimal. The patterns observed coincided with: the believer in control; the yea-sayer; the pure chance; the pure internal; the pure professional; and the nay-sayer clusters. The double external or type VI clusters were not observed. Clusters could be classified from the best to the worst adjustment to chronic pain. CONCLUSIONS: These results support the empirical validity of the theoretical model of LOC patterns proposed in 1982 by Wallston and Wallston among a chronic pain population. The analysis of patterns provides more accurate information regarding the adjustment to pain compared with analysis of the LOC factors separately. PMID:23936894

  14. A locus regulating bronchial hyperresponsiveness maps to chromosome 5q

    SciTech Connect

    Levitt, R.C.; Meyers, D.A.; Bleecker, E.R.

    1994-09-01

    Bronchial hyperresponsiveness (BHR) is one of the hallmarks of asthma. BHR correlates well with asthmatic symptoms and the response to treatment. Moreover, BHR appears to be closely related to airways inflammation. Numerous studies have demonstrated a familial aggregation; however, this phenotype is not likely inherited as a simple Mendelian trait. BHR is also closely associated with total serum IgE levels, as are allergy and asthma. We studied 92 families from Northern Holland ascertained through a parent with asthma who were originally studied between 1962-1970. Since there are a number of candidate genes on chromosome 5q potentially important in producing BHR, families were genotyped for markers in this region. These genes regulate IgE production and the cellular elements that are likely involved in inflammation associated with BHR, allergy and asthma. They include IL-4, IL-3, IL-5, IL-9, IL-12, IL-13 and GM-CSF. Linkage of BHR with markers on 5q was tested using a model free sib-pair method. The data suggest a locus for BHR maps near the cytokine gene cluster on 5q. This region appears critical in producing susceptibility to BHR and possibly to asthma.

  15. A Quantitative Trait Locus Influencing Anxiety in the Laboratory Rat

    PubMed Central

    Fernández-Teruel, Alberto; Escorihuela, Rosa M.; Gray, Jeffrey A.; Aguilar, Raúl; Gil, Luis; Giménez-Llort, Lydia; Tobeña, Adolf; Bhomra, Amarjit; Nicod, Alison; Mott, Richard; Driscoll, Peter; Dawson, Gerard R.; Flint, Jonathan

    2002-01-01

    A critical test for a gene that influences susceptibility to fear in animals is that it should have a consistent pattern of effects across a broad range of conditioned and unconditioned models of anxiety. Despite many years of research, definitive evidence that genetic effects operate in this way is lacking. The limited behavioral test regimes so far used in genetic mapping experiments and the lack of suitable multivariate methodologies have made it impossible to determine whether the quantitative trait loci (QTL) detected to date specifically influence fear-related traits. Here we report the first multivariate analysis to explore the genetic architecture of rodent behavior in a battery of animal models of anxiety. We have mapped QTLs in an F2 intercross of two rat strains, the Roman high and low avoidance rats, that have been selectively bred for differential response to fear. Multivariate analyses show that one locus, on rat chromosome 5, influences behavior in different models of anxiety. The QTL influences two-way active avoidance, conditioned fear, elevated plus maze, and open field activity but not acoustic startle response or defecation in a novel environment. The direction of effects of the QTL alleles and a coincidence between the behavioral profiles of anxiolytic drug and genetic action are consistent with the QTL containing at least one gene with a pleiotropic action on fear responses. As the neural basis of fear is conserved across species, we suggest that the QTL may have relevance to trait anxiety in humans. PMID:11932246

  16. Analysis of the pathogenicity locus in Clostridium difficile strains.

    PubMed

    Cohen, S H; Tang, Y J; Silva, J

    2000-02-01

    The genes for Clostridium difficile toxins A and B (tcdA and tcdB) are part of a 19.6-kb pathogenicity locus (PaLoc) that includes the genes tcdD, tcdE, and tcdC. To determine whether the C. difficile PaLoc is a stable and conserved genetic unit in toxigenic strains, a multiplex polymerase chain reaction was used to analyze 50 toxigenic, 39 nontoxigenic, and 2 toxin-defective isolates. The respective amplicons were identified for tcdA-E in the toxigenic isolates; these were absent in the nontoxigenic isolates. C. difficile P-829 lacked at least a fragment of tcdD, tcdB, tcdE, and tcdC, but tcdA was present. C. difficile 8864 had deletions in the tcdA and tcdC genes. These data suggest that the PaLoc is highly stable in toxigenic C. difficile, nontoxigenic isolates lack the unit, and isolates with a defective PaLoc can still cause clinical disease. Further studies are needed to define the role of individual genes in the pathogenesis of C. difficile-associated diarrhea. PMID:10669352

  17. Locus coeruleus, norepinephrine and Aβ peptides in Alzheimer's disease

    PubMed Central

    Ross, Jennifer A.; McGonigle, Paul; Van Bockstaele, Elisabeth J.

    2015-01-01

    Monoaminergic brainstem systems have widespread projections that participate in many central processes and, when dysregulated, contribute to a plethora of neuropsychiatric and neurodegenerative disorders. Synapses are the foundation of these neuronal circuits, and their local dysfunction results in global aberrations leading to pathophysiological disease states. This review focuses on the locus coeruleus (LC) norepinephrine (NE) brainstem system and its underappreciated role in Alzheimer's disease (AD). Amyloid beta (Aβ), a peptide that accumulates aberrantly in AD has recently been implicated as a modulator of neuronal excitability at the synapse. Evidence is presented showing that disruption of the LC-NE system at a synaptic and circuit level during early stages of AD, due to conditions such as chronic stress, can potentially lead to amyloid accumulation and contribute to the progression of this neurodegenerative disorder. Additional factors that impact neurodegeneration include neuroinflammation, and network de-synchronization. Consequently, targeting the LC-NE system may have significant therapeutic potential for AD, as it may facilitate modulation of Aβ production, curtail neuroinflammation, and prevent sleep and behavioral disturbances that often lead to negative patient outcomes. PMID:26618188

  18. Polymorphic DNA haplotypes at the LDL receptor locus.

    PubMed Central

    Leitersdorf, E; Chakravarti, A; Hobbs, H H

    1989-01-01

    Mutations in the low-density lipoprotein (LDL) receptor gene result in the autosomal dominant disorder familial hypercholesterolemia (FH). Many different LDL receptor mutations have been identified and characterized, demonstrating a high degree of allelic heterogeneity at this locus. The ability to identify mutant LDL receptor genes for prenatal diagnosis of homozygous FH or to study the role of the LDL receptor gene in polygenic hypercholesterolemia requires the use of closely linked RFLPs. In the present study we used 10 different RFLPs, including three newly described polymorphisms, to construct 123 independent haplotypes from 20 Caucasian American pedigrees. Our sample contained 31 different haplotypes varying in frequency from 0.8% to 29.3%; the five most common haplotypes account for 67.5% of the sample. The heterozygosity and PIC of each site were determined, and these values disclosed that eight of the RFLPs were substantially polymorphic. Linkage-disequilibrium analysis of the haplotype data revealed strong nonrandom associations among all 10 RFLPs, especially among those sites clustered in the 3' region of the gene. Evolutionary analysis suggests the occurrence of both mutational and recombinational events in the generation of the observed haplotypes. A strategy for haplotype analysis of the LDL receptor gene in individuals of Caucasian American descent is presented. Images Figure 2 Figure 3 PMID:2563635

  19. Quantitative trait locus mapping can benefit from segregation distortion.

    PubMed

    Xu, Shizhong

    2008-12-01

    Segregation distortion is a phenomenon that has been observed in many experimental systems. How segregation distortion among markers arises and its impact on mapping studies are the focus of this work. Segregation distortion of markers can be considered to arise from segregation distortion loci (SDL). I develop a theory of segregation distortion and show that the presence of only a few SDL can cause the entire chromosome to distort from Mendelian segregation. Segregation distortion is detrimental to the power of detecting quantitative trait loci (QTL) with dominance effects, but it is not always a detriment to QTL mapping for additive effects. When segregation distortion of a locus is a random event, the SDL is beneficial to QTL mapping approximately 44% of the time. If SDL are present and ignored, power loss can be substantial. A dense marker map can be used to ameliorate the situation, and if dense marker information is incorporated, power loss is minimal. However, other situations are less benign. A method that can simultaneously map QTL and SDL is discussed, maximizing both use of mapping resources and use by agricultural and evolutionary biologists. PMID:18957707

  20. Peripheral and central locus of a nonspeech phonetic context effect

    NASA Astrophysics Data System (ADS)

    Sullivan, Sarah C.; Lotto, Andrew J.

    2002-05-01

    Previous work has demonstrated that nonspeech sounds with the appropriate spectral characteristics can affect the identification of speech sounds [Lotto and Kluender, Percept. Psychophys. 60, 602-619 (1998)]. It has been proposed that these spectral context effects are due to interactions in the peripheral auditory system. For example, they could be the result of masking at the auditory nerve or of auditory enhancement effects that have been demonstrated to be monaural [Summerfield and Assmann, Percept. Psychophys. 45, 529-536 (1989)]. To examine the locus of the context effect, synthesized syllables varying from /da/ to /ga/ were preceded by single-formant stimuli that mimicked the third formant of the syllables /al/ and /ar/. The nonspeech stimulus was presented either to the same or opposite ear as the target speech stimulus. Subjects speech identifications were shifted as a function of context in predicted directions for both presentation conditions. However, the size of the shift was smaller when the context was in the ear contralateral to the target syllable. These results agree well with similar results for speech contexts. The data suggest that the context effects occur at multiple levels of the auditory system and are not simply examples of masking or auditory enhancement.

  1. Young adult women: lifestyle and health locus of control.

    PubMed

    Schank, M J; Lawrence, D M

    1993-08-01

    A study of 76 young adult women, 38 nursing students and 38 non-nursing students, examined their lifestyle practices and health locus of control (HLOC). Findings revealed a significant difference between reported lifestyle practices and the career choice of these young adult women. The lifestyle practice areas in which the most notable differences occurred included: use of seat belts, frequency of alcohol use, frequency of junk food intake, use of illegal drugs and hours of sleep per night. While differences in HLOC were evident between nursing and non-nursing students, no relationship was found between a young woman's HLOC and her lifestyle practices. The differences in HLOC showed that nurses were more frequently pure internal whereas most non-nurses were found to be double externals. The pure chance category had the fewest number of respondents. The difference in lifestyle practices between these young adult women can be explained in part by curriculum variations, as can the difference in HLOC patterns. PMID:8376662

  2. Rapid Multi-Locus Sequence Typing Using Microfluidic Biochips

    PubMed Central

    Read, Timothy D.; Turingan, Rosemary S.; Cook, Christopher; Giese, Heidi; Thomann, Ulrich Hans; Hogan, Catherine C.; Tan, Eugene; Selden, Richard F.

    2010-01-01

    Background Multiple locus sequence typing (MLST) has become a central genotyping strategy for analysis of bacterial populations. The scheme involves de novo sequencing of 6–8 housekeeping loci to assign unique sequence types. In this work we adapted MLST to a rapid microfluidics platform in order to enhance speed and reduce laboratory labor time. Methodology/Principal Findings Using two integrated microfluidic devices, DNA was purified from 100 Bacillus cereus soil isolates, used as a template for multiplex amplification of 7 loci and sequenced on forward and reverse strands. The time on instrument from loading genomic DNA to generation of electropherograms was only 1.5 hours. We obtained full-length sequence of all seven MLST alleles from 84 representing 46 different Sequence Types. At least one allele could be sequenced from a further 15 strains. The nucleotide diversity of B. cereus isolated in this study from one location in Rockville, Maryland (0.04 substitutions per site) was found to be as great as the global collection of isolates. Conclusions/Significance Biogeographical investigation of pathogens is only one of a panoply of possible applications of microfluidics based MLST; others include microbiologic forensics, biothreat identification, and rapid characterization of human clinical samples. PMID:20485679

  3. High Genetic Variability of the agr Locus in Staphylococcus Species

    PubMed Central

    Dufour, Philippe; Jarraud, Sophie; Vandenesch, Francois; Greenland, Timothy; Novick, Richard P.; Bes, Michele; Etienne, Jerome; Lina, Gerard

    2002-01-01

    The agr quorum-sensing and signal transduction system was initially described in Staphylococcus aureus, where four distinct allelic variants have been sequenced. Western blotting suggests the presence of homologous loci in many other staphylococci, and this has been confirmed for S. epidermidis and S. lugdunensis. In this study we isolated agr-like loci from a range of staphylococci by using PCR amplification from primers common to the six published agr sequences and bracketing the most variable region, associated with quorum-sensing specificity. Positive amplifications were obtained from 14 of 34 staphylococcal species or subspecies tested. Sequences of the amplicons identified 24 distinct variants which exhibited extensive sequence divergence with only 10% of the nucleotides absolutely conserved on multiple alignment. This variability involved all three open reading frames involved in quorum sensing and signal transduction. However, these variants retained several protein signatures, including the conserved cysteine residue of the autoinducing peptide, with the exception of S. intermedius of pigeon origin, which contained a serine in place of cysteine at this position. We discuss hypotheses on the mode of action and the molecular evolution of the agr locus based on comparisons between the newly determined sequences. PMID:11807079

  4. Control of arousal through neuropeptide afferents of the locus coeruleus.

    PubMed

    Zitnik, Gerard A

    2016-06-15

    The locus coeruleus-norepinephine (LC-NE) system is implicated in mediating several aspects of arousal. Alterations in LC neuronal discharge is associated with distinct changes in behavior, cognition, sensory processing and regulation of the sleep-wake cycle. Changes in LC output and subsequent release of NE in target brain regions help adjust arousal state to respond appropriately to environmental conditions and behavioral circumstances. One way in which LC activity is controlled is through release of endogenous neuropeptides. Based on the sleep-wake cycle and environmental cues specific neuropeptide afferent systems are activated, innervating the LC. These neuropeptides include: corticotropin releasing factor (CRF), orexin (ORX), endogenous opioids, substance P (SP), melanin-concentrating hormone (MCH), neuropeptide Y (NPY) and somatostatin (SS). This review summarizes studies examining the neuroanatomical projections of these neuropeptides, their receptors in the LC, the actions on LC neurons and downstream NE release, as well as the behavioral and cognitive effects associated individual neuropeptide-mediated innervation of the LC. Finally, the relationship between individual neuropeptides, the LC-NE system and various clinical disorders is discussed, providing evidence for possible therapeutic targets for treatment of several arousal- and stress-related disorders. This article is part of a Special Issue entitled SI: Noradrenergic System. PMID:26688115

  5. The achromatic locus: effect of navigation direction in color space.

    PubMed

    Chauhan, Tushar; Perales, Esther; Xiao, Kaida; Hird, Emily; Karatzas, Dimosthenis; Wuerger, Sophie

    2014-01-01

    An achromatic stimulus is defined as a patch of light that is devoid of any hue. This is usually achieved by asking observers to adjust the stimulus such that it looks neither red nor green and at the same time neither yellow nor blue. Despite the theoretical and practical importance of the achromatic locus, little is known about the variability in these settings. The main purpose of the current study was to evaluate whether achromatic settings were dependent on the task of the observers, namely the navigation direction in color space. Observers could either adjust the test patch along the two chromatic axes in the CIE u*v* diagram or, alternatively, navigate along the unique-hue lines. Our main result is that the navigation method affects the reliability of these achromatic settings. Observers are able to make more reliable achromatic settings when adjusting the test patch along the directions defined by the four unique hues as opposed to navigating along the main axes in the commonly used CIE u*v* chromaticity plane. This result holds across different ambient viewing conditions (Dark, Daylight, Cool White Fluorescent) and different test luminance levels (5, 20, and 50 cd/m(2)). The reduced variability in the achromatic settings is consistent with the idea that internal color representations are more aligned with the unique-hue lines than the u* and v* axes. PMID:24464164

  6. Functional analysis of the yeast plasmid partition locus STB

    PubMed Central

    Murray, James A. H.; Cesareni, Gianni

    1986-01-01

    Derivatives of the yeast 2μ plasmid with the cis-acting locus STB (also called REP3) are stably maintained if two plasmid-encoded proteins are present in trans. There are conflicting reports of both the extent of STB and its possible involvement in plasmid partition or copy number control. We have resolved the controversy by constructing 2µ derivatives with a conditional STB function, and showing that when STB is inactivated plasmids become concentrated in a small fraction of the population although the total number of plasmids remains unaltered. Moreover we show that STB consists of two functionally distinct domains which we call STB-proximal and STB-distal relative to the origin of replication. Although STB-proximal is sufficient for proper partitioning, this function is severely disrupted by active transcription from neighbouring sequences. STB-distal is important to protect STB-proximal and ORI from such transcription, and can be effeciently replaced by a 94-bp terminator fragment in an orientation-dependent manner. We find that STB-distal contains an additional element which depresses transcription from upstream promoters. We also describe the phenomenon of replicaton inhibition which we believe can exlain the anomalous instability of some yeast plasmids. ImagesFig. 4.Fig. 5.Fig. 6.Fig. 7. PMID:16453734

  7. 12q24 locus association with type 1 diabetes: SH2B3 or ATXN2?

    PubMed Central

    Auburger, Georg; Gispert, Suzana; Lahut, Suna; Ömür, Özgür; Damrath, Ewa; Heck, Melanie; Başak, Nazlı

    2014-01-01

    Genetic linkage analyses, genome-wide association studies of single nucleotide polymorphisms, copy number variation surveys, and mutation screenings found the human chromosomal 12q24 locus, with the genes SH2B3 and ATXN2 in its core, to be associated with an exceptionally wide spectrum of disease susceptibilities. Hematopoietic traits of red and white blood cells (like erythrocytosis and myeloproliferative disease), autoimmune disorders (like type 1 diabetes, coeliac disease, juvenile idiopathic arthritis, rheumatoid arthritis, thrombotic antiphospholipid syndrome, lupus erythematosus, multiple sclerosis, hypothyroidism and vitiligo), also vascular pathology (like kidney glomerular filtration rate deficits, serum urate levels, plasma beta-2-microglobulin levels, retinal microcirculation problems, diastolic and systolic blood pressure and hypertension, cardiovascular infarction), furthermore obesity, neurodegenerative conditions (like the polyglutamine-expansion disorder spinocerebellar ataxia type 2, Parkinson’s disease, the motor-neuron disease amyotrophic lateral sclerosis, and progressive supranuclear palsy), and finally longevity were reported. Now it is important to clarify, in which ways the loss or gain of function of the locally encoded proteins SH2B3/LNK and ataxin-2, respectively, contribute to these polygenic health problems. SH2B3/LNK is known to repress the JAK2/ABL1 dependent proliferation of white blood cells. Its null mutations in human and mouse are triggers of autoimmune traits and leukemia (acute lymphoblastic leukemia or chronic myeloid leukemia-like), while missense mutations were found in erythrocytosis-1 patients. Ataxin-2 is known to act on RNA-processing and trophic receptor internalization. While its polyglutamine-expansion mediated gain-of-function causes neuronal atrophy in human and mouse, its deletion leads to obesity and insulin resistance in mice. Thus, it is conceivable that the polygenic pathogenesis of type 1 diabetes is

  8. A familial hypertrophic cardiomyopathy locus maps to chromosome 15q2.

    PubMed Central

    Thierfelder, L; MacRae, C; Watkins, H; Tomfohrde, J; Williams, M; McKenna, W; Bohm, K; Noeske, G; Schlepper, M; Bowcock, A

    1993-01-01

    We report that a gene responsible for familial hypertrophic cardiomyopathy (FHC) in a kindred with a mild degree of cardiac hypertrophy maps to chromosome 15q2. The gene encoding cardiac actin, located on chromosome 15q, was analyzed and excluded as a candidate for FHC at this locus. Two additional families with typical FHC were studied and the disorder in one also maps to the chromosome 15q2 locus. The maximum combined multipoint logarithm of odds score in the two linked families is 6.02. Although these two kindreds reside in the same country, we believe that their disorder is caused by independent mutations in the 15q2 locus because of the clinical and genotypic differences between affected individuals. Mutations in at least four loci can cause FHC: chromosomes 14q1 (beta cardiac myosin heavy chain gene), 1q3, and 15q2 and another unidentified locus, suggesting substantial genetic heterogeneity. PMID:8327508

  9. Lack of a genetic association between the TNXB locus and schizophrenia in a Chinese population.

    PubMed

    Liu, Lin-Lin; Wei, Jun; Zhang, Xuan; Li, Xiu-Yi; Shen, Yan; Liu, Shu-Zheng; Ju, Gui-Zhi; Shi, Jie-Ping; Yu, Ya-Qin; Xu, Qi; Hemmings, Gwynneth P

    2004-01-23

    A recent study demonstrated that the tenascin X (TNXB) gene was associated with schizophrenia in a British population. To replicate the initial finding, we analysed two positive single nucleotide polymorphisms (SNPs), rs1009382 and rs204887 present at the TNXB locus, in a Chinese population by using PCR-based restriction fragment length polymorphism analysis. We recruited a total of 136 family trios consisting of fathers, mothers and affected offspring with schizophrenia. The transmission disequilibrium test did not show allelic association between these two SNPs and schizophrenia, and the rs1009382-rs204887 haplotypes were not associated with the illness either. The present results suggest that the TNXB locus does not appear to be associated with schizophrenia in the Chinese population. Because the TNXB gene is less than 100 kb away from the NOTCH4 locus that was also reported to be associated with schizophrenia, allelic and locus heterogeneity could be possible reasons for the failure to replicate the TNXB finding. PMID:14729256

  10. Genetic heterogeneity in benign familial neonatal convulsions: Identification of a new locus on chromosome 8q

    SciTech Connect

    Lewis, T.B.; Leach, R.J.; O'Connell, P.; Ryan, S.G. ); Ward, K. )

    1993-09-01

    The syndrome of benign familial neonatal convulsions (BFNC) is a rare autosomal dominant disorder characterized by unprovoked seizures in the first weeks of life. One locus for BFNC has been mapped to chromosome 20 in several pedigrees, but the authors have excluded linkage to chromosome 20 in one large kindred. In order to identify this novel BFNC locus, dinucleotide repeat markers distributed throughout the genome were used to screen this family. Maximum pairwise LOD scores of 4.43 were obtained with markers D8S284 and D8S256 on chromosome 8q. Multipoint analysis placed the BFNC locus in the interval spanned by D8S198-D8S274. This study establishes the presence of a new BFNC locus and confirms genetic heterogeneity of this disorder. 26 refs., 3 figs., 1 tab.

  11. Internal-External Locus of Control and Labor Market Performance: Empirical Evidence Using Longitudinal Survey Data.

    ERIC Educational Resources Information Center

    Frantz, Roger S.

    1980-01-01

    Internal-external control affects hourly wages independent of other factors such as educational attainment, labor market experience, race, and collective bargaining affiliation. Internal-external locus of control is affected by labor market success, race, and city size. (Author)

  12. Vocational interests of adolescents: relationships between self-esteem and locus of control.

    PubMed

    Mullis, A K; Mullis, R L

    1997-12-01

    The purpose of this study was to examine relationships among scores on vocational interests, self-esteem, and locus of control for high school students. Grade and sex differences were also examined. 1364 high school students ranging in age from 14 to 19 years of age were administered the Coopersmith Self-esteem Inventory, Nowicki-Strickland Locus of Control Scale for Children, and the Strong-Campbell Interest Inventory. High school students with higher scores on self-esteem and showing an orientation toward internal locus of control expressed more interests in a variety of vocational themes than adolescents with lower scores on self-esteem and scores for external locus of control. Sex and grade differences in vocational interests of adolescents were also noted. The findings were discussed in light of theoretical and practical considerations. PMID:9461772

  13. A genetic locus of enterocyte effacement conserved among diverse enterobacterial pathogens.

    PubMed Central

    McDaniel, T K; Jarvis, K G; Donnenberg, M S; Kaper, J B

    1995-01-01

    Enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic E. coli O157:H7 are intestinal pathogens that profoundly damage the microvilli and subapical cytoskeleton of epithelial cells. Here we report finding in EPEC a 35-kbp locus containing several regions implicated in formation of these lesions. DNA probes throughout this locus hybridize to E. coli O157:H7 and other pathogens of three genera that cause similar lesions but do not hybridize to avirulent members of the same species. The EPEC locus and a different virulence locus of uropathogenic E. coli insert into the E. coli chromosome at the identical site and share highly similar sequences near the point of insertion. Images Fig. 1 Fig. 3 PMID:7878036

  14. Lexical Access and Dual-Task Performance: Determining the Locus of the Bottleneck

    NASA Technical Reports Server (NTRS)

    Allen, Phil

    2004-01-01

    During the two years of funding for NASA Grant "NCC21325, Lexical access and dual-task performance: Determining the locus of the bottleneck," we completed three experiments involving the psychological refractory period (PRP) and word frequency.

  15. Factor Structure of Children's Locus of Control Beliefs: A Cross-Cultural Approach.

    ERIC Educational Resources Information Center

    Barling, Julian

    1980-01-01

    Nowicki characterized children's locus of control beliefs in terms of three factors: helplessness, luck, and achievement. This study investigated whether these factors are sufficiently consistent or invariant to be used in further analyses. (Author/DB)

  16. Effects of a Structured Camp Experience on Locus of Control Orientation

    ERIC Educational Resources Information Center

    Nowicki, Stephen, Jr.; Barnes, Jarvis

    1973-01-01

    Inner-city teenagers experienced a structured camp program for a week. It was predicted and found that this experience led to a change toward internality, in the locus of control orientation of these youngsters. (Authors)

  17. Self-Parental Alientation and Locus of Control in Delinquent Girls

    ERIC Educational Resources Information Center

    Duke, Marshall P.; Fenhagen, Eulalie

    1975-01-01

    Examines and confirms the hypotheses that delinquent females would have greater external locus of control and prefer greater distance from others. The implications of these results for the rehabilitation of delinquents are discussed. (GO)

  18. The Relationship between Adjustment and Perceived Locus of Control for Female Psychiatric Inpatients.

    ERIC Educational Resources Information Center

    Youkilis, Hildreth D.; Bootzin, Richard R.

    1979-01-01

    Examines the longitudinal relationship between internal-external locus of control and adjustment using independent measures within two dissimilar treatment environments: a traditional ward and a token economy ward. Subjects were 65 female psychiatric inpatients. (CM)

  19. Lantibiotic resistance.

    PubMed

    Draper, Lorraine A; Cotter, Paul D; Hill, Colin; Ross, R Paul

    2015-06-01

    The dramatic rise in the incidence of antibiotic resistance demands that new therapeutic options will have to be developed. One potentially interesting class of antimicrobials are the modified bacteriocins termed lantibiotics, which are bacterially produced, posttranslationally modified, lanthionine/methyllanthionine-containing peptides. It is interesting that low levels of resistance have been reported for lantibiotics compared with commercial antibiotics. Given that there are very few examples of naturally occurring lantibiotic resistance, attempts have been made to deliberately induce resistance phenotypes in order to investigate this phenomenon. Mechanisms that hinder the action of lantibiotics are often innate systems that react to the presence of any cationic peptides/proteins or ones which result from cell well damage, rather than being lantibiotic specific. Such resistance mechanisms often arise due to altered gene regulation following detection of antimicrobials/cell wall damage by sensory proteins at the membrane. This facilitates alterations to the cell wall or changes in the composition of the membrane. Other general forms of resistance include the formation of spores or biofilms, which are a common mechanistic response to many classes of antimicrobials. In rare cases, bacteria have been shown to possess specific antilantibiotic mechanisms. These are often species specific and include the nisin lytic protein nisinase and the phenomenon of immune mimicry. PMID:25787977

  20. Lantibiotic Resistance

    PubMed Central

    Draper, Lorraine A.; Ross, R. Paul

    2015-01-01

    SUMMARY The dramatic rise in the incidence of antibiotic resistance demands that new therapeutic options will have to be developed. One potentially interesting class of antimicrobials are the modified bacteriocins termed lantibiotics, which are bacterially produced, posttranslationally modified, lanthionine/methyllanthionine-containing peptides. It is interesting that low levels of resistance have been reported for lantibiotics compared with commercial antibiotics. Given that there are very few examples of naturally occurring lantibiotic resistance, attempts have been made to deliberately induce resistance phenotypes in order to investigate this phenomenon. Mechanisms that hinder the action of lantibiotics are often innate systems that react to the presence of any cationic peptides/proteins or ones which result from cell well damage, rather than being lantibiotic specific. Such resistance mechanisms often arise due to altered gene regulation following detection of antimicrobials/cell wall damage by sensory proteins at the membrane. This facilitates alterations to the cell wall or changes in the composition of the membrane. Other general forms of resistance include the formation of spores or biofilms, which are a common mechanistic response to many classes of antimicrobials. In rare cases, bacteria have been shown to possess specific antilantibiotic mechanisms. These are often species specific and include the nisin lytic protein nisinase and the phenomenon of immune mimicry. PMID:25787977

  1. [BLG gene knockout and hLF gene knock-in at BLG locus in goat by TALENs].

    PubMed

    Song, Shaozheng; Zhu, Mengmin; Yuan, Yuguo; Rong, Yao; Xu, Sheng; Chen, Si; Mei, Junyan; Cheng, Yong

    2016-03-01

    To knock out β-lactoglobulin (BLG) gene and insert human lactoferrin (hLF) coding sequence at BLG locus of goat, the transcription activator-like effector nucleases (TALEN) mediated recombination was used to edit the BLG gene of goat fetal fibroblast, then as donor cells for somatic cell nuclear transfer. We designed a pair of specific plasmid TALEN-3-L/R for goat BLG exon III recognition sites, and BLC14-TK vector containing a negative selection gene HSV-TK, was used for the knock in of hLF gene. TALENs plasmids were transfected into the goat fetal fibroblast cells, and the cells were screened three days by 2 μg/mL puromycin. DNA cleavage activities of cells were verified by PCR amplification and DNA production sequencing. Then, targeting vector BLC14-TK and plasmids TALEN-3-L/R were co-transfected into goat fetal fibroblasts, both 700 μg/mL G418 and 2 μg/mL GCV were simultaneously used to screen G418-resistant cells. Detections of integration and recombination were implemented to obtain cells with hLF gene site-specific integration. We chose targeting cells as donor cells for somatic cell nuclear transfer. The mutagenicity of TALEN-3-L/R was between 25% and 30%. A total of 335 reconstructed embryos with 6 BLG-/hLF+ targeting cell lines were transferred into 16 recipient goats. There were 9 pregnancies confirmed by ultrasound on day 30 to 35 (pregnancy rate of 39.1%), and one of 50-day-old fetus with BLG-/hLF+ was achieved. These results provide the basis for hLF gene knock-in at BLG locus of goat and cultivating transgenic goat of low allergens and rich hLF in the milk. PMID:27349115

  2. Polymorphisms within the Novel Type 2 Diabetes Risk Locus MTNR1B Determine β-Cell Function

    PubMed Central

    Staiger, Harald; Machicao, Fausto; Schäfer, Silke A.; Kirchhoff, Kerstin; Kantartzis, Konstantinos; Guthoff, Martina; Silbernagel, Günther; Stefan, Norbert; Häring, Hans-Ulrich; Fritsche, Andreas

    2008-01-01

    Background Very recently, a novel type 2 diabetes risk gene, i.e., MTNR1B, was identified and reported to affect fasting glycemia. Using our thoroughly phenotyped cohort of subjects at an increased risk for type 2 diabetes, we assessed the association of common genetic variation within the MTNR1B locus with obesity and prediabetes traits, namely impaired insulin secretion and insulin resistance. Methodology/Principal Findings We genotyped 1,578 non-diabetic subjects, metabolically characterized by oral glucose tolerance test, for five tagging single nucleotide polymorphisms (SNPs) covering 100% of common genetic variation (minor allele frequency >0.05) within the MTNR1B locus (rs10830962, rs4753426, rs12804291, rs10830963, rs3781638). In a subgroup (N = 513), insulin sensitivity was assessed by hyperinsulinemic-euglycemic clamp, and in a further subgroup (N = 301), glucose-stimulated insulin secretion was determined by intravenous glucose tolerance test. After appropriate adjustment for confounding variables and Bonferroni correction for multiple comparisons, none of the tagging SNPs was reliably associated with measures of adiposity. SNPs rs10830962, rs4753426, and rs10830963 were significantly associated with higher fasting plasma glucose concentrations (p<0.0001) and reduced OGTT- and IVGTT-induced insulin release (p≤0.0007 and p≤0.01, respectively). By contrast, SNP rs3781638 displayed significant association with lower fasting plasma glucose levels and increased OGTT-induced insulin release (p<0.0001 and p≤0.0002, respectively). Moreover, SNP rs3781638 revealed significant association with elevated fasting- and OGTT-derived insulin sensitivity (p≤0.0021). None of the MTNR1B tagging SNPs altered proinsulin-to-insulin conversion. Conclusions/Significance In conclusion, common genetic variation within MTNR1B determines glucose-stimulated insulin secretion and plasma glucose concentrations. Their impact on β-cell function might represent the

  3. Amplification of the murine mdr2 gene and a reconsideration of the structure of the murine mdr gene locus.

    PubMed

    Kirschner, L S

    1995-01-01

    A common feature of cells selected in vitro for the multidrug resistance (MDR) phenotype is the amplification and concomitant overexpression of the mdr genes. In murine macrophage-like J774.2-derived MDR cell lines, there is a good correlation between levels of amplification and expression for the mdr1b gene, but not for the other two gene family members, mdr1a and mdr2. To understand this phenomenon better, a study of the amplification and expression of the mdr2 gene was undertaken. Southern blotting of genomic DNAs from a series of six MDR cell lines revealed that five of these lines had 5'-end amplification of mdr2, whereas only three contained 3'-end amplification. The analysis also suggested the involvement of a recombination hot-spot in this phenomenon. Despite the observation that the ratio between the number of copies of the 5' and 3' ends of the gene differs among cell lines, the ratio of 5' to 3' end transcription of mdr2 was approximately 1 in all cell lines. An analysis of promoter methylation in MDR cell lines demonstrated that this mechanism may play a role in regulating the transcription of mdr2, but not of mdr1b. Long-range mapping of the mdr locus in parental and amplified cell lines suggested that the three mdr genes are oriented in the same direction, and also revealed the presence of a number of rearrangement events. Models for the murine mdr gene locus in wild-type cells and in a cell line containing a rearrangement are presented. PMID:7832992

  4. Mining locus tags in PubMed Central to improve microbial gene annotation

    PubMed Central

    2014-01-01

    Background The scientific literature contains millions of microbial gene identifiers within the full text and tables, but these annotations rarely get incorporated into public sequence databases. We propose to utilize the Open Access (OA) subset of PubMed Central (PMC) as a gene annotation database and have developed an R package called pmcXML to automatically mine and extract locus tags from full text, tables and supplements. Results We mined locus tags from 1835 OA publications in ten microbial genomes and extracted tags mentioned in 30,891 sentences in main text and 20,489 rows in tables. We identified locus tag pairs marking the start and end of a region such as an operon or genomic island and expanded these ranges to add another 13,043 tags. We also searched for locus tags in supplementary tables and publications outside the OA subset in Burkholderia pseudomallei K96243 for comparison. There were 168 publications containing 48,470 locus tags and 83% of mentions were from supplementary materials and 9% from publications outside the OA subset. Conclusions B. pseudomallei locus tags within the full text and tables of OA publications represent only a small fraction of the total mentions in the literature. For microbial genomes with very few functionally characterized proteins, the locus tags mentioned in supplementary tables and within ranges like genomic islands contain the majority of locus tags. Significantly, the functions in the R package provide access to additional resources in the OA subset that are not currently indexed or returned by searching PMC. PMID:24499370

  5. A Mycobacterium tuberculosis IS6110 preferential locus (ipl) for insertion into the genome.

    PubMed Central

    Fang, Z; Forbes, K J

    1997-01-01

    A 267-nucleotide Mycobacterium tuberculosis genomic sequence (ipl, the IS6110 preferential locus) which can harbor the insertion sequence IS6110 at six alternative locations has been identified in some three-quarters of the isolates tested. Only one IS6110 copy was observed at this locus in the ipl::IS6110(+)-containing isolates tested, and all insertions had the same orientation. The implications of this finding for IS6110 fingerprint typing methods is discussed in this work. PMID:9003621

  6. Perception of severity of disease and health locus of control in compliant and noncompliant diabetic patients.

    PubMed

    Alogna, M

    1980-01-01

    Compliant and noncompliant obese, non-insulin-dependent diabetic subjects were assessed using a variety of demographic variables, the health locus of control scale (HLC), and the perception of severity of disease index based on the health belief model. The complaint subjects were significantly older and viewed their illness as significantly more severe than the noncompliant patients. Additionally, they tended to exhibit more of an internal locus of control that the noncompliant patients. PMID:7460724

  7. Hysteresis zone or locus - Aerodynamic of bulbous based bodies at low speeds

    NASA Technical Reports Server (NTRS)

    Covert, E. E.

    1979-01-01

    Experimental data are presented which seem to suggest that a well-defined hysteresis locus on bulbous based bodies at low speeds does not exist. Instead, if the experiment is repeated several times, the entire hysteresis region seems to fill with data rather than trace out a specific hysteresis locus. Data obtained on an oscillating model even at low reduced frequencies may be well defined but when applied to arbitrary motion lead to less accurate results than desired.

  8. A second locus for Rieger syndrome maps to chromosome 13q14.

    PubMed Central

    Phillips, J. C.; del Bono, E. A.; Haines, J. L.; Pralea, A. M.; Cohen, J. S.; Greff, L. J.; Wiggs, J. L.

    1996-01-01

    Rieger syndrome is a genetically and phenotypically heterogeneous disorder typically characterized by malformations of the eyes, teeth, and umbilicus. The syndrome is inherited as an autosomal dominant trait and exhibits significant variable expressivity. One locus associated with this disorder has been mapped to 4q25. Using a large four-generation pedigree, we have identified a second locus for Rieger syndrome located on chromosome 13q14. PMID:8751862

  9. Locus heterogeneity disease genes encode proteins with high interconnectivity in the human protein interaction network

    PubMed Central

    Keith, Benjamin P.; Robertson, David L.; Hentges, Kathryn E.

    2014-01-01

    Mutations in genes potentially lead to a number of genetic diseases with differing severity. These disease genes have been the focus of research in recent years showing that the disease gene population as a whole is not homogeneous, and can be categorized according to their interactions. Locus heterogeneity describes a single disorder caused by mutations in different genes each acting individually to cause the same disease. Using datasets of experimentally derived human disease genes and protein interactions, we created a protein interaction network to investigate the relationships between the products of genes associated with a disease displaying locus heterogeneity, and use network parameters to suggest properties that distinguish these disease genes from the overall disease gene population. Through the manual curation of known causative genes of 100 diseases displaying locus heterogeneity and 397 single-gene Mendelian disorders, we use network parameters to show that our locus heterogeneity network displays distinct properties from the global disease network and a Mendelian network. Using the global human proteome, through random simulation of the network we show that heterogeneous genes display significant interconnectivity. Further topological analysis of this network revealed clustering of locus heterogeneity genes that cause identical disorders, indicating that these disease genes are involved in similar biological processes. We then use this information to suggest additional genes that may contribute to diseases with locus heterogeneity. PMID:25538735

  10. Rosa26 Locus Supports Tissue-Specific Promoter Driving Transgene Expression Specifically in Pig

    PubMed Central

    Ma, Jing; Huang, Tianqing; Jiang, Dandan; Xie, Bingteng; Wu, Meiling; Wang, Jiaqiang; Song, Yuran; Wang, Ying; He, Yilong; Sun, Jialu; Hu, Kui; Guo, Runfa; Wang, Liu; Zhou, Qi; Mu, Yanshuang; Liu, Zhonghua

    2014-01-01

    Genetically modified pigs have become a popular model system in fundamental research, agricultural and biomedical applications. However, random integration often result in unstable expression of transgene and unpredictable phenotypes. The Rosa26 locus has been widely used to produce genetic modified animals with high and consistent expressing of transgene in mouse, human and rat, as it can be targeted efficiently and is not subject to gene-silencing effects. Recently, the first case of reporter gene targeting pigs in porcine Rosa26 (pRosa26) locus was reported. In the study, full sequence of pRosa26 locus was further characterized, and the pRosa26 promoter (pR26) was cloned and we evidenced that the new porcine endogenous promoter is suitable for driving transgene expression in a high and stable manner by avoiding DNA methylation. Furthermore, elongation factor 1a promoter (EF1a) -driven GFP reporter and Myostatin promoter (MyoP)-driven Follistatin (Fst) were successfully targeted into the pRosa26 locusby traditional homologous recombination (HR) strategy. EF1a showed high activity and hypomethylation at the locus. And, muscle-specific promoter MyoP was activated strictly in muscle of the pRosa26 targeted pigs, indicating Rosa26 locus supports tissue-specific promoter driving transgene expression in its own manner. The study provided further demonstration on biomedical and agricultural applications of porcine Rosa26 promoter and locus. PMID:25232950

  11. Donor Locus Selection during Saccharomyces Cerevisiae Mating Type Interconversion Responds to Distant Regulatory Signals

    PubMed Central

    Weiler, K. S.; Broach, J. R.

    1992-01-01

    Mating type interconversion in homothallic strains of the yeast Saccharomyces cerevisiae results from directed transposition of a mating type allele from one of the two silent donor loci, HML and HMR, to the expressing locus, MAT. Cell type regulates the selection of the particular donor locus to be utilized during mating type interconversion: MATa cells preferentially select HMLα and MATα cells preferentially select HMRa. Such preferential selection indicates that the cell is able to distinguish between HML and HMR during mating type interconversion. Accordingly, we designed experiments to identify those features perceived by the cell to discriminate HML and HMR. We demonstrate that discrimination does not derive from the different structures of the HML and HMR loci, from the unique sequences flanking each donor locus nor from any of the DNA distal to the HM loci on chromosome III. Moreover, we find that the sequences flanking the MAT locus do not function in the preferential selection of one donor locus over the other. We propose that the positions of the donor loci on the left and right arms of chromosome III is the characteristic utilized by the cell to distinguish HML and HMR. This positional information is not generated by either CEN3 or the MAT locus, but probably derives from differences in the chromatin structure, chromosome folding or intranuclear localization of the two ends of chromosome III. PMID:1459444

  12. Health locus of control and self-care behaviors in diabetic foot patients

    PubMed Central

    Abredari, Hamid; Bolourchifard, Fariba; Rassouli, Maryam; Nasiri, Navideh; Taher, Mohammad; Abedi, Ahmadreza

    2015-01-01

    Background: Diabetic foot affects more than 25% of diabetic patients and finally up to 20% of cases result in amputation. The most important factor resulting in severe complications or even death is lack of self-care. Health locus of control has been introduced as one of health factors and predicting factors of self-care. This research was performed for analyzing the correlation between self-care behaviors and health locus of control in diabetic foot patients. Methods: In this descriptive study, 120 patients with diabetic foot were chosen using convenience sampling from endocrine clinic and wards of endocrine and vascular surgery of Teleqani Hospital of Shahid Beheshti Medical University. The data were gathered by demographic, self-care behavior, and health locus of control questionnaires. The t-test, analysis of variance (ANOVA) and spearman coefficient were used to analyze the data. Results: Results of this research showed that there is a direct and significant relation between selfcare behaviors and internal health locus of control (p<0.001), and also in contrast with chance health locus of control (p<0.001). Conclusion: We have to consider these factors’ role in nursing interventions and patient-care education programs and plans. Probably, interventions and programs that will lead to the strengthening of internal health locus of control improve and strengthen patients’ self-care behaviors and their involvement in treatment. PMID:26913246

  13. Phenotypic and genetic characterization of resistance in Arabidopsis thaliana to the oomycete pathogen Phytophthora parasitica

    PubMed Central

    Meng, Yuling; Huang, Yihua; Wang, Qinhu; Wen, Qujiang; Jia, Jinbu; Zhang, Qiang; Huang, Guiyan; Quan, Junli; Shan, Weixing

    2015-01-01

    The interaction between Arabidopsis thaliana and the oomycete pathogen Phytophthora parasitica emerges as a model for exploring the molecular basis and evolution of recognition and host defense. Phenotypic variation and genetic analysis is essential to dissect the underlying mechanisms in plant–oomycete interaction. In this study, the reaction phenotypes of 28 A. thaliana accessions to P. parasitica strain Pp016 were examined using detached leaf infection assay. The results showed the presence of four distinct groups based on host response and disease development. Of all the accessions examined, Zurich (Zu-1) is highly resistant to P. parasitica. Microscopic characterization showed that rapid and severe hypersensitive response at the primary infection epidermal cells is associated with disease resistance. Furthermore, Zu-1 is resistant to a set of 20 diverse P. parasitica strains, which were collected from different host plants and exhibited differential specificities on a set of tobacco cultivars. However, Zu-1 is susceptible to P. parasitica when the root is inoculated, suggesting differential expression of associated resistance genes in the root and foliar tissues. Genetic analysis by crossing Zu-1 and the susceptible accession Landsberg (Ler) showed that the resistance in Zu-1 to P. parasitica is semi-dominant, as shown by infection assays of F1 progenies, and is likely conferred by a single locus, defined as RPPA1Zu-1 (for Resistance to P. parasitica 1), as shown by analysis of F2 segregating populations. By employing specific-locus amplified fragment sequencing (SLAF-seq) strategy to identify molecular markers potentially linked to the locus, the strongest associated region was determined to be located between 7.1 and 11.2 Mb in chromosome IV. The future cloning of RPPA1Zu-1 locus will facilitate improved understanding of plant broad-spectrum disease resistance to oomycete pathogens. PMID:26074940

  14. Molecular Characterization of Multidrug-Resistant Isolates of Mycobacterium tuberculosis from Patients in North India

    PubMed Central

    Siddiqi, Noman; Shamim, Mohammed; Hussain, Seema; Choudhary, Rakesh Kumar; Ahmed, Niyaz; Prachee; Banerjee, Sharmistha; Savithri, G. R.; Alam, Mahfooz; Pathak, Niteen; Amin, Amol; Hanief, Mohammed; Katoch, V. M.; Sharma, S. K.; Hasnain, Seyed E.

    2002-01-01

    The World Health Organization has identified India as a major hot-spot region for Mycobacterium tuberculosis infection. We have characterized the sequences of the loci associated with multidrug resistance in 126 clinical isolates of M. tuberculosis from India to identify the respective mutations. The loci selected were rpoB (rifampin), katG and the ribosomal binding site of inhA (isoniazid), gyrA and gyrB (ofloxacin), and rpsL and rrs (streptomycin). We found known as well as novel mutations at these loci. Few of the mutations at the rpoB locus could be correlated with the drug resistance levels exhibited by the M. tuberculosis isolates and occurred with frequencies different from those reported earlier. Missense mutations at codons 526 to 531 seemed to be crucial in conferring a high degree of resistance to rifampin. We identified a common Arg463Leu substitution in the katG locus and certain novel insertions and deletions. Mutations were also mapped in the ribosomal binding site of the inhA gene. A Ser95Thr substitution in the gyrA locus was the most common mutation observed in ofloxacin-resistant isolates. A few isolates showed other mutations in this locus. Seven streptomycin-resistant isolates had a silent mutation at the lysine residue at position 121. While certain mutations are widely present, pointing to the magnitude of the polymorphisms at these loci, others are not common, suggesting diversity in the multidrug-resistant M. tuberculosis strains prevalent in this region. Our results additionally have implications for the development of methods for multidrug resistance detection and are also relevant in the shaping of future clinical treatment regimens and drug design strategies. PMID:11796356

  15. Diverse genetic basis of field-evolved resistance to Bt cotton in cotton bollworm from China

    PubMed Central

    Zhang, Haonan; Tian, Wen; Zhao, Jing; Jin, Lin; Yang, Jun; Liu, Chunhui; Yang, Yihua; Wu, Shuwen; Wu, Kongming; Cui, Jinjie; Tabashnik, Bruce E.; Wu, Yidong

    2012-01-01

    Evolution of pest resistance reduces the efficacy of insecticidal proteins from Bacillus thuringiensis (Bt) used in sprays or in transgenic crops. Although several pests have evolved resistance to Bt crops in the field, information about the genetic basis of field-evolved resistance to Bt crops has been limited. In particular, laboratory-selected resistance to Bt toxin Cry1Ac based on recessive mutations in a gene encoding a toxin-binding cadherin protein has been identified in three major cotton pests, but previous work has not determined if such mutations are associated with field-selected resistance to Bt cotton. Here we show that the most common resistance alleles in field populations of cotton bollworm, Helicoverpa armigera, selected with Bt cotton in northern China, had recessive cadherin mutations, including the deletion mutation identified via laboratory selection. However, unlike all previously studied cadherin resistance alleles, one field-selected cadherin resistance allele conferred nonrecessive resistance. We also detected nonrecessive resistance that was not genetically linked with the cadherin locus. In field-selected populations, recessive cadherin alleles accounted for 75–84% of resistance alleles detected. However, most resistance alleles occurred in heterozygotes and 59–94% of resistant individuals carried at least one nonrecessive resistance allele. The results suggest that resistance management strategies must account for diverse resistance alleles in field-selected populations, including nonrecessive alleles. PMID:22689968

  16. Two-locus diseas models with two marker loci: The power of affected-sib-pair tests

    SciTech Connect

    Knapp, M.; Seuchter, S.A.; Bauer, M.P.

    1994-11-01

    Recently, Schork et al. found that two-trait-locus, two-marker-locus (parametric) linkage analysis can provide substantially more linkage information than can standard one-trait-locus, one-marker-locus methods. However, because of the increased burden of computation, Schork et al. do not expect that their approach will be applied in an initial genome scan. Further, the specification of a suitable two-locus segregation model can be crucial. Affected-sib-pair tests are computationally simple and do not require an explicit specification of the disease model. In the past, however, these tests mainly have been applied to data with a single marker locus. Here, we consider sib-pair tests that make it possible to analyze simultaneously two marker loci. The power of these tests is investigated for different (epistatic and heterogeneous) two-trait-locus models, each trait locus being linked to one of the marker loci. We compare these tests both with the test that is optimal for a certain model and with the strategy that analyzes each marker locus separately. The results indicate that a straightforward extension of the well-known mean test for two marker loci can be much more powerful than single-marker-locus analysis and that its power is only slightly inferior to the power of the optimal test. 21 refs., 5 figs., 2 tabs.

  17. Complex patterns of intragenic polymorphism at the PDGFA locus.

    PubMed

    Bonthron, D T; Smith, S J; Campbell, R

    1999-11-01

    The human platelet-derived growth factor A chain gene (PDGFA) on chromosome 7p22 encodes an important mitogen. Within PDGFA lies a complex minisatellite structure that results in partial duplications of exon 4 and the IVS4 splice donor site. Here, we show that the PDGFA genes of four ape species and an Old-World monkey all have similar complex minisatellites at this position. Comparison of their structures suggests evolutionary constraints resulting from the protein-coding function of the minisatellite. Nonetheless, the IVS4 minisatellite seems to have undergone independent expansion events in different primate lineages. Within the human IVS4 minisatellite, an embedded pentanucleotide repeat, based on the sequence (CCTCC)n, shows frequent subunit sequence variation but only rare length polymorphism. In contrast, within IVS3 of human PDGFA, we have discovered a second minisatellite which, unlike the IVS4 minisatellite, is highly polymorphic. The subunit sequences of these two minisatellites, which lie less than 0.5 kb apart, are non-identical, but share a CnT-rich core. Two new single nucleotide polymorphisms (SNPs), in exon 3 and IVS4, are in linkage disequilibrium, despite flanking the two minisatellite regions. Reverse transcription-polymerase chain reaction analysis of the exon 3 SNP in human foetal tissues demonstrated biallelic expression of PDGFA in all tissues examined. The unusual location of PDGFA exon 4 between two minisatellite sequences, together with its partial duplication, may have functional implications, particularly for the splicing of the gene. The high level of polymorphism demonstrated in this region will also be valuable for disease-association and linkage studies of the PDGFA locus. PMID:10598812

  18. Molecular analysis of the maize anthocyanin regulatory locus C1.

    PubMed Central

    Cone, K C; Burr, F A; Burr, B

    1986-01-01

    The C1 gene of maize plays a regulatory role in the production of anthocyanin pigments in the aleurone layer of the endosperm. As an initial step toward understanding the molecular details of how C1 controls pigment biosynthesis, we cloned the C1 gene. This was accomplished by first cloning a mutable allele of C1, c1-m5, which contains the transposable element Spm. A combination of molecular and genetic analysis was used to identify the Spm at the C1 locus. Individual genomic DNAs from a population in which the c1-mutable phenotype was segregating with the recessive c1 phenotype were digested with methyl-sensitive restriction enzymes and probed with a small DNA fragment derived from a defective Spm. One Sal I restriction fragment complementary to the Spm probe was shown to be present in the DNA of individuals with the c1-m5 phenotype but absent from DNA of individuals with a recessive c1 phenotype. Subsequent cloning and restriction analysis of this fragment revealed sequences flanking the Spm that proved to be C1-specific. A DNA fragment derived from the flanking sequences was then used as a probe to clone the wild-type C1 gene and several additional alleles of C1, including one stable recessive, two mutations caused by Ds insertions, one mutation induced by insertion of a defective Spm, and two dominant mutations, C1-S and C1-I. RNA blot hybridization analysis of three C1 alleles indicates that C1 regulation of the Bz1 and A1 structural genes in the anthocyanin biosynthetic pathway is at the transcriptional level. Images PMID:3025847

  19. ABI3 controls embryo degreening through Mendel's I locus

    PubMed Central

    Delmas, Frédéric; Sankaranarayanan, Subramanian; Deb, Srijani; Widdup, Ellen; Bournonville, Céline; Bollier, Norbert; Northey, Julian G. B.; McCourt, Peter; Samuel, Marcus A.

    2013-01-01

    Chlorophyll (chl) is essential for light capture and is the starting point that provides the energy for photosynthesis and thus plant growth. Obviously, for this reason, retention of the green chlorophyll pigment is considered a desirable crop trait. However, the presence of chlorophyll in mature seeds can be an undesirable trait that can affect seed maturation, seed oil quality, and meal quality. Occurrence of mature green seeds in oil crops such as canola and soybean due to unfavorable weather conditions during seed maturity is known to cause severe losses in revenue. One recently identified candidate that controls the chlorophyll degradation machinery is the stay-green gene, SGR1 that was mapped to Mendel’s I locus responsible for cotyledon color (yellow versus green) in peas. A defect in SGR1 leads to leaf stay-green phenotypes in Arabidopsis and rice, but the role of SGR1 in seed degreening and the signaling machinery that converges on SGR1 have remained elusive. To decipher the gene regulatory network that controls degreening in Arabidopsis, we have used an embryo stay-green mutant to demonstrate that embryo degreening is achieved by the SGR family and that this whole process is regulated by the phytohormone abscisic acid (ABA) through ABSCISIC ACID INSENSITIVE 3 (ABI3); a B3 domain transcription factor that has a highly conserved and essential role in seed maturation, conferring desiccation tolerance. Misexpression of ABI3 was sufficient to rescue cold-induced green seed phenotype in Arabidopsis. This finding reveals a mechanistic role for ABI3 during seed degreening and thus targeting of this pathway could provide a solution to the green seed problem in various oil-seed crops. PMID:24043799

  20. Clinical Clostridium difficile: clonality and pathogenicity locus diversity.

    PubMed

    Dingle, Kate E; Griffiths, David; Didelot, Xavier; Evans, Jessica; Vaughan, Alison; Kachrimanidou, Melina; Stoesser, Nicole; Jolley, Keith A; Golubchik, Tanya; Harding, Rosalind M; Peto, Tim E; Fawley, Warren; Walker, A Sarah; Wilcox, Mark; Crook, Derrick W

    2011-01-01

    Clostridium difficile infection (CDI) is an important cause of mortality and morbidity in healthcare settings. The major virulence determinants are large clostridial toxins, toxin A (tcdA) and toxin B (tcdB), encoded within the pathogenicity locus (PaLoc). Isolates vary in pathogenicity from hypervirulent PCR-ribotypes 027 and 078 with high mortality, to benign non-toxigenic strains carried asymptomatically. The relative pathogenicity of most toxigenic genotypes is still unclear, but may be influenced by PaLoc genetic variant. This is the largest study of C. difficile molecular epidemiology performed to date, in which a representative collection of recent isolates (n = 1290) from patients with CDI in Oxfordshire, UK, was genotyped by multilocus sequence typing. The population structure was described using NeighborNet and ClonalFrame. Sequence variation within toxin B (tcdB) and its negative regulator (tcdC), was mapped onto the population structure. The 69 Sequence Types (ST) showed evidence for homologous recombination with an effect on genetic diversification four times lower than mutation. Five previously recognised genetic groups or clades persisted, designated 1 to 5, each having a strikingly congruent association with tcdB and tcdC variants. Hypervirulent ST-11 (078) was the only member of clade 5, which was divergent from the other four clades within the MLST loci. However, it was closely related to the other clades within the tcdB and tcdC loci. ST-11 (078) may represent a divergent formerly non-toxigenic strain that acquired the PaLoc (at least) by genetic recombination. This study focused on human clinical isolates collected from a single geographic location, to achieve a uniquely high density of sampling. It sets a baseline of MLST data for future comparative studies investigating genotype virulence potential (using clinical severity data for these isolates), possible reservoirs of human CDI, and the evolutionary origins of hypervirulent strains