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Sample records for pm3 resistance locus

  1. 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

  2. Intragenic allele pyramiding combines different specificities of wheat Pm3 resistance alleles.

    PubMed

    Brunner, Susanne; Hurni, Severine; Streckeisen, Philipp; Mayr, Gabriele; Albrecht, Mario; Yahiaoui, Nabila; Keller, Beat

    2010-11-01

    Some plant resistance genes occur as allelic series, with each member conferring specific resistance against a subset of pathogen races. In wheat, there are 17 alleles of the Pm3 gene. They encode nucleotide-binding (NB-ARC) and leucine-rich-repeat (LRR) domain proteins, which mediate resistance to distinct race spectra of powdery mildew. It is not known if specificities from different alleles can be combined to create resistance genes with broader specificity. Here, we used an approach based on avirulence analysis of pathogen populations to characterize the molecular basis of Pm3 recognition spectra. A large survey of mildew races for avirulence on the Pm3 alleles revealed that Pm3a has a resistance spectrum that completely contains that of Pm3f, but also extends towards additional races. The same is true for the Pm3b and Pm3c gene pair. The molecular analysis of these allelic pairs revealed a role of the NB-ARC protein domain in the efficiency of effector-dependent resistance. Analysis of the wild-type and chimeric Pm3 alleles identified single residues in the C-terminal LRR motifs as the main determinant of allele specificity. Variable residues of the N-terminal LRRs are necessary, but not sufficient, to confer resistance specificity. Based on these data, we constructed a chimeric Pm3 gene by intragenic allele pyramiding of Pm3d and Pm3e that showed the combined resistance specificity and, thus, a broader recognition spectrum compared with the parental alleles. Our findings support a model of stepwise evolution of Pm3 recognition specificities.

  3. Rye Pm8 and wheat Pm3 are orthologous genes and show evolutionary conservation of resistance function against powdery mildew.

    PubMed

    Hurni, Severine; Brunner, Susanne; Buchmann, Gabriele; Herren, Gerhard; Jordan, Tina; Krukowski, Patricia; Wicker, Thomas; Yahiaoui, Nabila; Mago, Rohit; Keller, Beat

    2013-12-01

    The improvement of wheat through breeding has relied strongly on the use of genetic material from related wild and domesticated grass species. The 1RS chromosome arm from rye was introgressed into wheat and crossed into many wheat lines, as it improves yield and fungal disease resistance. Pm8 is a powdery mildew resistance gene on 1RS which, after widespread agricultural cultivation, is now widely overcome by adapted mildew races. Here we show by homology-based cloning and subsequent physical and genetic mapping that Pm8 is the rye orthologue of the Pm3 allelic series of mildew resistance genes in wheat. The cloned gene was functionally validated as Pm8 by transient, single-cell expression analysis and stable transformation. Sequence analysis revealed a complex mosaic of ancient haplotypes among Pm3- and Pm8-like genes from different members of the Triticeae. These results show that the two genes have evolved independently after the divergence of the species 7.5 million years ago and kept their function in mildew resistance. During this long time span the co-evolving pathogens have not overcome these genes, which is in strong contrast to the breakdown of Pm8 resistance since its introduction into commercial wheat 70 years ago. Sequence comparison revealed that evolutionary pressure acted on the same subdomains and sequence features of the two orthologous genes. This suggests that they recognize directly or indirectly the same pathogen effectors that have been conserved in the powdery mildews of wheat and rye.

  4. Mapping of crown gall resistance locus Rcg1 in grapevine.

    PubMed

    Kuczmog, Anett; Galambos, Anikó; Horváth, Szabina; Mátai, Anikó; Kozma, Pál; Szegedi, Ernő; Putnoky, Péter

    2012-11-01

    Agrobacteria are efficient plant pathogens. They are able to transform plant cells genetically resulting in abnormal cell proliferation. Cultivars of Vitis vinifera are highly susceptible to many virulent Agrobacterium strains but certain wild Vitis species, including Vitis amurensis have resistant genotypes. Studies of the molecular background of such natural resistance are of special importance, not only for practical benefits in agricultural practice but also for understanding the role of plant genes in the transformation process. Earlier, crown gall resistance from V. amurensis was introgressed into V. vinifera through interspecific breeding and it was shown to be inherited as a single and dominant Mendelian trait. To develop this research further, towards understanding underlying molecular mechanisms, a mapping population was established, and resistance-coupled molecular DNA markers were identified by three different approaches. First, RAPD makers linked to the resistance locus (Rcg1) were identified, and on the basis of their DNA sequences, we developed resistance-coupled SCAR markers. However, localization of these markers in the grapevine genome sequence failed due to their similarity to many repetitive regions. Next, using SSR markers of the grapevine reference linkage map, location of the resistance locus was established on linkage group 15 (LG15). Finally, this position was supported further by developing new chromosome-specific markers and by the construction of the genetic map of the region including nine loci in 29.1 cM. Our results show that the closest marker is located 3.3 cM from the Rcg1 locus that may correspond to 576 kb. PMID:22801874

  5. Mapping of crown gall resistance locus Rcg1 in grapevine.

    PubMed

    Kuczmog, Anett; Galambos, Anikó; Horváth, Szabina; Mátai, Anikó; Kozma, Pál; Szegedi, Ernő; Putnoky, Péter

    2012-11-01

    Agrobacteria are efficient plant pathogens. They are able to transform plant cells genetically resulting in abnormal cell proliferation. Cultivars of Vitis vinifera are highly susceptible to many virulent Agrobacterium strains but certain wild Vitis species, including Vitis amurensis have resistant genotypes. Studies of the molecular background of such natural resistance are of special importance, not only for practical benefits in agricultural practice but also for understanding the role of plant genes in the transformation process. Earlier, crown gall resistance from V. amurensis was introgressed into V. vinifera through interspecific breeding and it was shown to be inherited as a single and dominant Mendelian trait. To develop this research further, towards understanding underlying molecular mechanisms, a mapping population was established, and resistance-coupled molecular DNA markers were identified by three different approaches. First, RAPD makers linked to the resistance locus (Rcg1) were identified, and on the basis of their DNA sequences, we developed resistance-coupled SCAR markers. However, localization of these markers in the grapevine genome sequence failed due to their similarity to many repetitive regions. Next, using SSR markers of the grapevine reference linkage map, location of the resistance locus was established on linkage group 15 (LG15). Finally, this position was supported further by developing new chromosome-specific markers and by the construction of the genetic map of the region including nine loci in 29.1 cM. Our results show that the closest marker is located 3.3 cM from the Rcg1 locus that may correspond to 576 kb.

  6. 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

  7. Origin and maintenance of a broad-spectrum disease resistance locus in Arabidopsis.

    PubMed

    Xiao, Shunyuan; Emerson, Brent; Ratanasut, Kumrop; Patrick, Elaine; O'Neill, Carmel; Bancroft, Ian; Turner, John G

    2004-09-01

    The broad-spectrum mildew resistance genes RPW8.1 and RPW8.2 define a unique type of plant disease resistance (R) gene, and so far homologous sequences have been found in Arabidopsis thaliana only, which suggests a recent origin. In addition to RPW8.1 and RPW8.2, the RPW8 locus contains three homologs of RPW8, HR1, HR2, and HR3, which do not contribute to powdery mildew resistance. To investigate whether RPW8 has originated recently, and if so the processes involved, we have isolated and analyzed the syntenic RPW8 loci from Arabidopsis lyrata, and from Brassica rapa and B. oleracea. The A. lyrata locus contains four genes orthologous to HR1, HR2, HR3, and RPW8.2, respectively. Two syntenic loci have been characterized in Brassica; one locus contains three genes and is present in both B. oleracea and B. rapa, and the other locus contains a single gene and is detected in B. rapa only. The Brassica homologs have highest similarity to HR3. Sequence analyses suggested that the RPW8 gene family in Brassicaceae originated from an HR3-like ancestor gene through a series of duplications and that RPW8.1 and RPW8.2 evolved from functional diversification through positive selection several MYA. Examination of the sequence polymorphism of 32 A. thaliana accessions at the RPW8 locus and their disease reaction phenotypes revealed that the polymorphic RPW8 locus defines a major source of resistance to powdery mildew diseases. A possible evolutionary mechanism by which functional polymorphism at the AtRPW8 locus has been maintained in contemporary populations of A. thaliana is discussed.

  8. 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 ...

  9. 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

  10. Isolation of a genetic locus associated with metronidazole resistance in Helicobacter pylori.

    PubMed

    Chang, K C; Ho, S W; Yang, J C; Wang, J T

    1997-07-30

    We examined the molecular mechanism of metronidazole resistance by constructing a lambda-Zap II phagemid expression library with genomic DNA from a metronidazole-resistance strain of Helicobacter pylori. Twenty-two clones were found to have elevated MTZ resistances in XLOLR strain of E. coli. Phagemids belonging to the twenty two clones were extracted and then retransformed into the XLOLR strain of E. coli. After MTZ selection, five clones could confer metronidazole resistance consistently. According to Southern hybridization and DNA sequencing, the five clones contained a same locus, recA. In addition, transforming the five clones into BL21 strain of E. coli produced a higher resistance to MTZ. Interestingly, electroporation of one of the five phagemid clones into two MTZ sensitive H. pylori yielded MTZ resistant strains. Comparing amino acid sequence in MTZ resistant with sensitive isolates revealed two point mutations at this locus. Above results suggest that mutation in recA may be associated with metronidazole resistance of H. pylori. PMID:9245734

  11. Identification and mapping of resistance gene analogs and a white rust resistance locus in Brassica rapa ssp. oleifera.

    PubMed

    Tanhuanpää, P

    2004-04-01

    The objective of this investigation was to tag a locus for white rust resistance in a Brassica rapa ssp. oleifera F(2) population segregating for this trait, using bulked segregant analysis with random amplified polymorphic DNA (RAPD) markers, linkage mapping and a candidate gene approach based on resistance gene analogs (RGAs). The resistance source was the Finnish line Bor4109. The reaction against white rust races 7a and 7v was scored in 20 seedlings from each self-pollinated F(2 )individual. The proportion of resistant plants among these F(3) families varied from 0 to 67%. Bulked segregant analysis did not reveal any markers linked with resistance and, therefore, a linkage map with 81 markers was created. A locus that accounted for 18.4% of the variation in resistance to white rust was mapped to linkage group (LG) 2 near the RAPD marker Z19a. During the study, a bacterial resistance gene homologous to Arabidopsis RPS2 and six different RGAs were sequenced. RPS2 and five of the RGAs were mapped to linkage groups LG1, LG4 and LG9. Unfortunately, none of the RGAs could be shown to be associated with white rust resistance.

  12. An aphid-resistance locus is tightly linked to the nematode-resistance gene, Mi, in tomato.

    PubMed Central

    Kaloshian, I; Lange, W H; Williamson, V M

    1995-01-01

    Tomato lines from diverse breeding programs were evaluated in the field for resistance to a natural infestation of the potato aphid, Macrosiphum euphorbiae, in Davis, CA. It was noted that all lines that carried the nematode-resistance gene, Mi, displayed aphid resistance. A greenhouse assay for aphid resistance was developed to investigate this relationship. Association of nematode and aphid resistances in near-isogenic lines suggested that these traits are tightly linked. Analysis of an F2 population segregating for nematode resistance indicated that aphid resistance segregated as a single major locus genetically linked to Mi. The name Meu1 is proposed for this locus. It is likely that Meu1 was introduced into tomato along with Mi from the wild species Lycopersicon peruvianum. The presence of aphid resistance in the line Motelle, which contains a very small region of introgressed DNA, and the lack of recombinants suggest that Meu1 is tightly linked to Mi or possibly is the same gene. The map-based strategy currently being used to clone Mi should be applicable to cloning Meu1. Images Fig. 1 PMID:11607509

  13. The sexually linked Mpi locus is presumably involved in imidothiazole resistance in Oesophagostomum dentatum parasites.

    PubMed

    Snábel, V; DeMeeŵs, T; Várady, M; Nansen, P; Bjørn, H; Corba, J

    2000-06-01

    Information about genetic changes during the selection process could indicate mechanisms underlying the spread of resistance to anthelmintic drugs. For clarification of the role of the Mpi locus encoding mannose-phosphate isomerase enzyme in determining resistance, genotyping of Oesophagostomum dentatum strains was performed using an isoelectrofocusing technique. In levamisole- and pyrantel-selected strains the allele associated with resistance has probably been found. Significant values for genetic differentiation between treated and untreated strains of common origin were recorded by F(st) indices (theta = 0.078; P = 0.0008). The specific genomic makeup of a flubendazole-resistant strain, which did not correlate with that of the remaining isolates, might be ascribed to a different action of the anthelmintic or different environmental conditions under which resistance against this drug arose. The absence of heterozygotes in male populations indicated an XX/X0 system of sex determination for the Mpi locus, thus providing a greater potential for the development of resistance. A possible involvement of alleles linked with mannose-phosphate isomerase in alterations of membrane receptors that can be associated with resistance against imidothiazole-based drugs is discussed.

  14. Selective sweep at the Rpv3 locus during grapevine breeding for downy mildew resistance.

    PubMed

    Di Gaspero, Gabriele; Copetti, Dario; Coleman, Courtney; Castellarin, Simone Diego; Eibach, Rudolf; Kozma, Pál; Lacombe, Thierry; Gambetta, Gregory; Zvyagin, Andrey; Cindrić, Petar; Kovács, László; Morgante, Michele; Testolin, Raffaele

    2012-02-01

    The Rpv3 locus is a major determinant of downy mildew resistance in grapevine (Vitis spp.). A selective sweep at this locus was revealed by the DNA genotyping of 580 grapevines, which include a highly diverse set of 265 European varieties that predated the spread of North American mildews, 82 accessions of wild species, and 233 registered breeding lines with North American ancestry produced in the past 150 years. Artificial hybridisation and subsequent phenotypic selection favoured a few Rpv3 haplotypes that were introgressed from wild vines and retained in released varieties. Seven conserved haplotypes in five descent groups of resistant varieties were traced back to their founders: (1) 'Munson', a cross between two of Hermann Jaeger's selections of V. rupestris and V. lincecumii made in the early 1880s in Missouri, (2) V. rupestris 'Ganzin', first utilised for breeding in 1879 by Victor Ganzin in France, (3) 'Noah', selected in 1869 from intermingled accessions of V. riparia and V. labrusca by Otto Wasserzieher in Illinois, (4) 'Bayard', a V. rupestris × V. labrusca offspring generated in 1882 by George Couderc in France, and (5) a wild form closely related to V. rupestris accessions in the Midwestern United States and introgressed into 'Seibel 4614' in the 1880s by Albert Seibel in France. Persistence of these Rpv3 haplotypes across many of the varieties generated by human intervention indicates that a handful of vines with prominent resistance have laid the foundation for modern grape breeding. A rampant hot spot of NB-LRR genes at the Rpv3 locus has provided a distinctive advantage for the adaptation of native North American grapevines to withstand downy mildew. The coexistence of multiple resistance alleles or paralogues in the same chromosomal region but in different haplotypes counteracts efforts to pyramidise them in a diploid individual via conventional breeding.

  15. 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

  16. 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

  17. 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

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. 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

  3. 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…

  4. A multiple resistance locus on chromosome arm 3BS in wheat confers resistance to stem rust (Sr2), leaf rust (Lr27) and powdery mildew.

    PubMed

    Mago, R; Tabe, L; McIntosh, R A; Pretorius, Z; Kota, R; Paux, E; Wicker, T; Breen, J; Lagudah, E S; Ellis, J G; Spielmeyer, W

    2011-08-01

    Sr2 is the only known durable, race non-specific adult plant stem rust resistance gene in wheat. The Sr2 gene was shown to be tightly linked to the leaf rust resistance gene Lr27 and to powdery mildew resistance. An analysis of recombinants and mutants suggests that a single gene on chromosome arm 3BS may be responsible for resistance to these three fungal pathogens. The resistance functions of the Sr2 locus are compared and contrasted with those of the adult plant resistance gene Lr34.

  5. Physical Mapping in a Triplicated Genome: Mapping the Downy Mildew Resistance Locus Pp523 in Brassica oleracea L.

    PubMed Central

    Carlier, Jorge D.; Alabaça, Claudia S.; Sousa, Nelson H.; Coelho, Paula S.; Monteiro, António A.; Paterson, Andrew H.; Leitão, José M.

    2011-01-01

    We describe the construction of a BAC contig and identification of a minimal tiling path that encompass the dominant and monogenically inherited downy mildew resistance locus Pp523 of Brassica oleracea L. The selection of BAC clones for construction of the physical map was carried out by screening gridded BAC libraries with DNA overgo probes derived from both genetically mapped DNA markers flanking the locus of interest and BAC-end sequences that align to Arabidopsis thaliana sequences within the previously identified syntenic region. The selected BAC clones consistently mapped to three different genomic regions of B. oleracea. Although 83 BAC clones were accurately mapped within a ∼4.6 cM region surrounding the downy mildew resistance locus Pp523, a subset of 33 BAC clones mapped to another region on chromosome C8 that was ∼60 cM away from the resistance gene, and a subset of 63 BAC clones mapped to chromosome C5. These results reflect the triplication of the Brassica genomes since their divergence from a common ancestor shared with A. thaliana, and they are consonant with recent analyses of the C genome of Brassica napus. The assembly of a minimal tiling path constituted by 13 (BoT01) BAC clones that span the Pp523 locus sets the stage for map-based cloning of this resistance gene. PMID:22384370

  6. A novel locus for clubroot resistance in Brassica rapa and its linkage markers.

    PubMed

    Hirai, M; Harada, T; Kubo, N; Tsukada, M; Suwabe, K; Matsumoto, S

    2004-02-01

    An inbred turnip ( Brassica rapa syn. campestris) line, N-WMR-3, which carries the trait of clubroot resistance (CR) from a European turnip, Milan White, was crossed with a clubroot-susceptible doubled haploid line, A9709. A segregating F(3) population was obtained by single-seed descent of F(2) plants and used for a genetic analysis. Segregation of CR in the F(3) population suggested that CR is controlled by a major gene. Two RAPD markers, OPC11-1 and OPC11-2, were obtained as candidates of linkage markers by bulked segregant analysis. These were converted to sequence-tagged site markers, by cloning and sequencing of the polymorphic bands, and named OPC11-1S and OPC11-2S, respectively. The specific primer pairs for OPC11-1S amplified a clear dominant band, while the primer pairs for OPC11-2S resulted in co-dominant bands. Frequency distributions and statistical analyses indicate the presence of a major dominant CR gene linked to these two markers. The present marker for CR was independent of the previously found CR loci, Crr1 and Crr2. Genotypic distribution and statistical analyses did not show any evidence of CR alleles on Crr1 and Crr2 loci in N-WMR-3. The present study clearly demonstrates that B. rapa has at least three CR loci. Therefore, the new CR locus was named Crr3. The present locus may be useful in breeding CR Chinese cabbage cultivars to overcome the decay of present CR cultivars.

  7. Identificaiton of a clubroot resistance locus conferring resistance to a Plasmodiophora brassicae classified into pathotype group 3 in Chinese cabbage (Brassica rapa L.).

    PubMed

    Kato, Takeyuki; Hatakeyama, Katsunori; Fukino, Nobuko; Matsumoto, Satoru

    2012-09-01

    In Chinese cabbage (Brassica rapa), the clubroot resistance (CR) genes Crr1 and Crr2 are effective against the mild Plasmodiophora brassicae isolate Ano-01 and the more virulent isolate Wakayama-01, but not against isolate No. 14, classified into pathotype group 3. 'Akiriso', a clubroot-resistant F(1) cultivar, showed resistance to isolate No. 14. To increase the durability of resistance, we attempted to identify the CR locus in 'Akiriso'. CR in 'Akiriso' segregated as a single dominant gene and was linked to several molecular markers that were also linked to CRb, a CR locus from cultivar 'CR Shinki'. We developed additional markers around CRb and constructed partial genetic maps of this region in 'Akiriso' and 'CR Shinki'. The positions and order of markers in the genetic maps of the two cultivars were very similar. The segregation ratios for resistance to isolate No. 14 in F(2) populations derived from each of the two cultivars were also very similar. These results suggest that the CR locus in 'Akiriso' is CRb or a tightly linked locus. The newly developed markers in this study were more closely linked to CRb than previously reported markers and will be useful for marker-assisted selection of CRb in Chinese cabbage breeding.

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

    PubMed Central

    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.

    2016-01-01

    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

  9. The arabidopsis ISR1 locus controlling rhizobacteria-mediated induced systemic resistance is involved in ethylene signaling.

    PubMed

    Ton, J; Davison, S; Van Wees, S C; Van Loon, L; Pieterse, C M

    2001-02-01

    In Arabidopsis, the rhizobacterial strain Pseudomonas fluorescens WCS417r triggers an induced systemic resistance (ISR) response that is effective against different types of pathogens. The ISR signaling pathway functions independent of salicylic acid, but requires responsiveness to jasmonate (JA) and ethylene. Using the genetic variability of ISR inducibility between Arabidopsis accessions, we recently identified a locus (ISR1) on chromosome III that is involved in ISR signaling. Accessions RLD and Wassilewskija (Ws) are recessive at the ISR1 locus and are, therefore, unable to develop ISR. Here we investigated whether the ISR1 locus is involved in JA or ethylene signaling. Compared with the ISR-inducible accession Columbia (Col), accessions RLD and Ws were not affected in JA-induced inhibition of root growth and expression of the JA-responsive gene Atvsp, suggesting that the ISR1 locus is not involved in JA signaling. However, RLD and Ws showed an affected expression of the triple response and a reduced expression of the ethylene responsive genes Hel and Pdf1.2 after exogenous application of the ethylene precursor 1-aminocyclopropane-1-carboxylate. Moreover, in contrast to Col, RLD and Ws did not develop resistance against P. syringae pv. tomato DC3000 after treatment of the leaves with 1-aminocyclopropane-1-carboxylate. Analysis of the F(2) and F(3) progeny of a cross between Col (ISR1/ISR1) and RLD (isr1/isr1) revealed that reduced sensitivity to ethylene cosegregates with the recessive alleles of the ISR1 locus. These results suggest that the ISR1 locus encodes a component of the ethylene response, which is required for the expression of rhizobacteria-mediated ISR.

  10. [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.

  11. [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

  12. Narrowing down the apricot Plum pox virus resistance locus and comparative analysis with the peach genome syntenic region.

    PubMed

    Vera Ruiz, Elsa María; Soriano, José Miguel; Romero, Carlos; Zhebentyayeva, Tetyana; Terol, Javier; Zuriaga, Elena; Llácer, Gerardo; Abbott, Albert Glenn; Badenes, María Luisa

    2011-08-01

    Sharka disease, caused by the Plum pox virus (PPV), is one of the main limiting factors for stone fruit crops worldwide. Only a few resistance sources have been found in apricot (Prunus armeniaca L.), and most studies have located a major PPV resistance locus (PPVres) on linkage group 1 (LG1). However, the mapping accuracy was not sufficiently reliable and PPVres was predicted within a low confidence interval. In this study, we have constructed two high-density simple sequence repeat (SSR) improved maps with 0.70 and 0.68 markers/cm, corresponding to LG1 of 'Lito' and 'Goldrich' PPV-resistant cultivars, respectively. Using these maps, and excluding genotype-phenotype incongruent individuals, a new binary trait locus (BTL) analysis for PPV resistance was performed, narrowing down the PPVres support intervals to 7.3 and 5.9 cm in 'Lito' and 'Goldrich', respectively. Subsequently, 71 overlapping oligonucleotides (overgo) probes were hybridized against an apricot bacterial artificial chromosome (BAC) library, identifying 870 single BACs from which 340 were anchored onto a map region of approximately 30-40 cm encompassing PPVres. Partial BAC contigs assigned to the two allelic haplotypes (resistant/susceptible) of the PPVres locus were built by high-information content fingerprinting (HICF). In addition, a total of 300 BAC-derived sequences were obtained, and 257 showed significant homology with the peach genome scaffold_1 corresponding to LG1. According to the peach syntenic genome sequence, PPVres was predicted within a region of 2.16 Mb in which a few candidate resistance genes were identified.

  13. Two seven-transmembrane domain MILDEW RESISTANCE LOCUS O proteins cofunction in Arabidopsis root thigmomorphogenesis.

    PubMed

    Chen, Zhongying; Noir, Sandra; Kwaaitaal, Mark; Hartmann, H Andreas; Wu, Ming-Jing; Mudgil, Yashwanti; Sukumar, Poornima; Muday, Gloria; Panstruga, Ralph; Jones, Alan M

    2009-07-01

    Directional root expansion is governed by nutrient gradients, positive gravitropism and hydrotropism, negative phototropism and thigmotropism, as well as endogenous oscillations in the growth trajectory (circumnutation). Null mutations in phylogenetically related Arabidopsis thaliana genes MILDEW RESISTANCE LOCUS O 4 (MLO4) and MLO11, encoding heptahelical, plasma membrane-localized proteins predominantly expressed in the root tip, result in aberrant root thigmomorphogenesis. mlo4 and mlo11 mutant plants show anisotropic, chiral root expansion manifesting as tightly curled root patterns upon contact with solid surfaces. The defect in mlo4 and mlo11 mutants is nonadditive and dependent on light and nutrients. Genetic epistasis experiments demonstrate that the mutant phenotype is independently modulated by the Gbeta subunit of the heterotrimeric G-protein complex. Analysis of expressed chimeric MLO4/MLO2 proteins revealed that the C-terminal domain of MLO4 is necessary but not sufficient for MLO4 action in root thigmomorphogenesis. The expression of the auxin efflux carrier fusion, PIN1-green fluorescent protein, the pattern of auxin-induced gene expression, and acropetal as well as basipetal auxin transport are altered at the root tip of mlo4 mutant seedlings. Moreover, addition of auxin transport inhibitors or the loss of EIR1/AGR1/PIN2 function abolishes root curling of mlo4, mlo11, and wild-type seedlings. These results demonstrate that the exaggerated root curling phenotypes of the mlo4 and mlo11 mutants depend on auxin gradients and suggest that MLO4 and MLO11 cofunction as modulators of touch-induced root tropism.

  14. Slow erosion of a quantitative apple resistance to Venturia inaequalis based on an isolate-specific Quantitative Trait Locus.

    PubMed

    Caffier, Valérie; Le Cam, Bruno; Al Rifaï, Mehdi; Bellanger, Marie-Noëlle; Comby, Morgane; Denancé, Caroline; Didelot, Frédérique; Expert, Pascale; Kerdraon, Tifenn; Lemarquand, Arnaud; Ravon, Elisa; Durel, Charles-Eric

    2016-10-01

    Quantitative plant resistance affects the aggressiveness of pathogens and is usually considered more durable than qualitative resistance. However, the efficiency of a quantitative resistance based on an isolate-specific Quantitative Trait Locus (QTL) is expected to decrease over time due to the selection of isolates with a high level of aggressiveness on resistant plants. To test this hypothesis, we surveyed scab incidence over an eight-year period in an orchard planted with susceptible and quantitatively resistant apple genotypes. We sampled 79 Venturia inaequalis isolates from this orchard at three dates and we tested their level of aggressiveness under controlled conditions. Isolates sampled on resistant genotypes triggered higher lesion density and exhibited a higher sporulation rate on apple carrying the resistance allele of the QTL T1 compared to isolates sampled on susceptible genotypes. Due to this ability to select aggressive isolates, we expected the QTL T1 to be non-durable. However, our results showed that the quantitative resistance based on the QTL T1 remained efficient in orchard over an eight-year period, with only a slow decrease in efficiency and no detectable increase of the aggressiveness of fungal isolates over time. We conclude that knowledge on the specificity of a QTL is not sufficient to evaluate its durability. Deciphering molecular mechanisms associated with resistance QTLs, genetic determinants of aggressiveness and putative trade-offs within pathogen populations is needed to help in understanding the erosion processes.

  15. Correlation between genetic features of the mef(A)-msr(D) locus and erythromycin resistance in Streptococcus pyogenes.

    PubMed

    Vitali, Luca Agostino; Di Luca, Maria Chiara; Prenna, Manuela; Petrelli, Dezemona

    2016-01-01

    We investigated the correlation between the genetic variation within mef(A)-msr(D) determinants of efflux-mediated erythromycin resistance in Streptococcus pyogenes and the level of erythromycin resistance. Twenty-eight mef(A)-positive strains were selected according to erythromycin MIC (4-32 μg/mL), and their mef(A)-msr(D) regions were sequenced. Strains were classified according to the bacteriophage carrying mef(A)-msr(D). A new Φm46.1 genetic variant was found in 8 strains out of 28 and named VP_00501.1. Degree of allelic variation was higher in mef(A) than in msr(D). Hotspots for recombination were mapped within the locus that could have shaped the apparent mosaic structure of the region. There was a general correlation between mef(A)-msr(D) sequence and erythromycin resistance level. However, lysogenic conversion of susceptible strains by mef(A)-msr(D)-carrying Φm46.1 indicated that key determinants may not all reside within the mef(A)-msr(D) locus and that horizontal gene transfer could contribute to changes in the level of antibiotic resistance in S. pyogenes.

  16. Sequence variation in the Trichuris trichiura beta-tubulin locus: implications for the development of benzimidazole resistance.

    PubMed

    Bennett, A B; Anderson, T J C; Barker, G C; Michael, E; Bundy, D A P

    2002-11-01

    Benzimidazole resistance has evolved in a variety of organisms and typically results from mutations in the beta-tubulin locus at specific amino acid sites. Despite widespread treatment of human intestinal nematodes with benzimidazole drugs, there have been no unambiguous reports of resistance. However, since beta-tubulin mutations conferring resistance are generally recessive, frequencies of resistance alleles less than 30% would be difficult to detect on the basis of drug treatment failures. Here we investigate sequence variation in a 1079 bp segment of the beta-tubulin locus in the human whipworm Trichuris trichiura from 72 individual nematodes from seven countries. We did not observe any alleles with amino acid mutations indicative of resistance, and of 40 point mutations there were only four non-synonymous mutations all of which were singletons. Estimated effective population sizes are an order of magnitude lower than those from another nematode species in which benzimidazole resistance has developed (Haemonchus contortus). Both the lower diversity and reduced population sizes suggest that benzimidazole resistance is likely to evolve less rapidly in Trichuris than in trichostrongyle parasites of livestock. We observed moderate levels of population subdivision (Phi(ST)=0.26) comparable with that previously observed in Ascaris lumbricoides, and identical alleles were frequently found in parasites from different continents, suggestive of recent admixture. A particularly interesting feature of the data is the high nucleotide diversities observed in nematodes from the Caribbean. This genetic complexity may be a direct result of extensive admixture and complex history of human populations in this region of the world. These data should encourage (but not make complacent) those involved in large-scale benzimidazole treatment of human intestinal nematodes.

  17. 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

  18. 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.

  19. Tandem amplification of a chromosomal segment harboring 5-enolpyruvylshikimate-3-phosphate synthase locus confers glyphosate resistance in Kochia scoparia.

    PubMed

    Jugulam, Mithila; Niehues, Kindsey; Godar, Amar S; Koo, Dal-Hoe; Danilova, Tatiana; Friebe, Bernd; Sehgal, Sunish; Varanasi, Vijay K; Wiersma, Andrew; Westra, Philip; Stahlman, Phillip W; Gill, Bikram S

    2014-11-01

    Recent rapid evolution and spread of resistance to the most extensively used herbicide, glyphosate, is a major threat to global crop production. Genetic mechanisms by which weeds evolve resistance to herbicides largely determine the level of resistance and the rate of evolution of resistance. In a previous study, we determined that glyphosate resistance in Kochia scoparia is due to the amplification of the 5-Enolpyruvylshikimate-3-Phosphate Synthase (EPSPS) gene, the enzyme target of glyphosate. Here, we investigated the genomic organization of the amplified EPSPS copies using fluorescence in situ hybridization (FISH) and extended DNA fiber (Fiber FISH) on K. scoparia chromosomes. In both glyphosate-resistant K. scoparia populations tested (GR1 and GR2), FISH results displayed a single and prominent hybridization site of the EPSPS gene localized on the distal end of one pair of homologous metaphase chromosomes compared with a faint hybridization site in glyphosate-susceptible samples (GS1 and GS2). Fiber FISH displayed 10 copies of the EPSPS gene (approximately 5 kb) arranged in tandem configuration approximately 40 to 70 kb apart, with one copy in an inverted orientation in GR2. In agreement with FISH results, segregation of EPSPS copies followed single-locus inheritance in GR1 population. This is the first report of tandem target gene amplification conferring field-evolved herbicide resistance in weed populations.

  20. Tandem amplification of a chromosomal segment harboring 5-enolpyruvylshikimate-3-phosphate synthase locus confers glyphosate resistance in Kochia scoparia.

    PubMed

    Jugulam, Mithila; Niehues, Kindsey; Godar, Amar S; Koo, Dal-Hoe; Danilova, Tatiana; Friebe, Bernd; Sehgal, Sunish; Varanasi, Vijay K; Wiersma, Andrew; Westra, Philip; Stahlman, Phillip W; Gill, Bikram S

    2014-11-01

    Recent rapid evolution and spread of resistance to the most extensively used herbicide, glyphosate, is a major threat to global crop production. Genetic mechanisms by which weeds evolve resistance to herbicides largely determine the level of resistance and the rate of evolution of resistance. In a previous study, we determined that glyphosate resistance in Kochia scoparia is due to the amplification of the 5-Enolpyruvylshikimate-3-Phosphate Synthase (EPSPS) gene, the enzyme target of glyphosate. Here, we investigated the genomic organization of the amplified EPSPS copies using fluorescence in situ hybridization (FISH) and extended DNA fiber (Fiber FISH) on K. scoparia chromosomes. In both glyphosate-resistant K. scoparia populations tested (GR1 and GR2), FISH results displayed a single and prominent hybridization site of the EPSPS gene localized on the distal end of one pair of homologous metaphase chromosomes compared with a faint hybridization site in glyphosate-susceptible samples (GS1 and GS2). Fiber FISH displayed 10 copies of the EPSPS gene (approximately 5 kb) arranged in tandem configuration approximately 40 to 70 kb apart, with one copy in an inverted orientation in GR2. In agreement with FISH results, segregation of EPSPS copies followed single-locus inheritance in GR1 population. This is the first report of tandem target gene amplification conferring field-evolved herbicide resistance in weed populations. PMID:25037215

  1. 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.

  2. RPS2, an Arabidopsis disease resistance locus specifying recognition of Pseudomonas syringae strains expressing the avirulence gene avrRpt2.

    PubMed Central

    Kunkel, B N; Bent, A F; Dahlbeck, D; Innes, R W; Staskawicz, B J

    1993-01-01

    A molecular genetic approach was used to identify and characterize plant genes that control bacterial disease resistance in Arabidopsis. A screen for mutants with altered resistance to the bacterial pathogen Pseudomonas syringae pv. tomato (Pst) expressing the avirulence gene avrRpt2 resulted in the isolation of four susceptible rps (resistance to P. syringae) mutants. The rps mutants lost resistance specifically to bacterial strains expressing avrRpt2 as they retained resistance to Pst strains expressing the avirulence genes avrB or avrRpm1. Genetic analysis indicated that in each of the four rps mutants, susceptibility was due to a single mutation mapping to the same locus on chromosome 4. Identification of a resistance locus with specificity for a single bacterial avirulence gene suggests that this locus, designated RPS2, controls specific recognition of bacteria expressing the avirulence gene avrRpt2. Ecotype Wü-0, a naturally occurring line that is susceptible to Pst strains expressing avrRpt2, appears to lack a functional allele at RPS2, demonstrating that there is natural variation at the RPS2 locus among wild populations of Arabidopsis. PMID:8400869

  3. 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

  4. 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...

  5. A new soybean rust resistance allele from PI 423972 at the Rpp4 locus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phakopsora pachyrhizi is a fungal pathogen and the cause of Asian soybean rust (SBR). P. pachyrhizi invaded the continental United States in 2004 and has since been a threat to the soybean industry. There are six described loci that harbor resistance to P. pachyrhizi (Rpp) genes. The resistance of P...

  6. High-resolution linkage map of mouse chromosome 13 in the vicinity of the host resistance locus Lgn1

    SciTech Connect

    Beckers, M.C.; Ernst, E.; Diez, E.

    1997-02-01

    Natural resistance of inbred mouse strains to infection with Legionella pneumophila is controlled by the expression of a single dominant gene on chromosome 13, designated Lgn1. The genetic difference at Lgn1 is phenotypically expressed as the presence or absence of intracellular replication of L. pneumophila in host macrophages. In our effort to identify the Lgn1 gene by positional cloning, we have generated a high-resolution linkage map of the Lgn1 chromosomal region. For this, we have carried out extensive segregation analysis in a total of 1270 (A/J x C57BL/6J) X A/J informative backcross mice segregating the resistance allele of C57BL/6J and the susceptibility allele of A/J. Additional segregation analyses were carried out in three preexisting panels of C57BL/6J X Mus spretus interspecific backcross mice. A total of 39 DNA markers were mapped within an interval of approximately 30 cM overlapping the Lgn1 region. Combined pedigree analyses for the 5.4-cM segment overlapping Lgn1 indicated the locus order and the interlocus distances (in cM): D13Mit128-(1.4)-D13Mit194-(0.1)-D13Mit147-(0.9)-Dl3Mit36-(0.9)-D13Mit146-(0.2)-Lgn1/D 13Mit37-(1.0)-D13Mit70. Additional genetic linkage studies of markers not informative in the A/J X C57BL/6J cross positioned D13Mit30, -72, -195, and -203, D13Gor4, D13Hun35, and Mtap5 in the immediate vicinity of the Lgn1 locus. The marker density and resolution of this genetic linkage map should allow the construction of a physical map of the region and the isolation of YAC clones overlapping the gene. 60 refs., 2 figs., 2 tabs.

  7. 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.

  8. 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

  9. Excision of the Shigella Resistance Locus Pathogenicity Island in Shigella flexneri Is Stimulated by a Member of a New Subgroup of Recombination Directionality Factors

    PubMed Central

    Luck, Shelley N.; Turner, Sally A.; Rajakumar, Kumar; Adler, Ben; Sakellaris, Harry

    2004-01-01

    Pathogenicity islands are capable of excision and insertion within bacterial chromosomes. We describe a protein, Rox, that stimulates excision of the Shigella resistance locus pathogenicity island in Shigella flexneri. Sequence analysis suggests that Rox belongs to a new subfamily of recombination directionality factors, which includes proteins from P4, enterohemorrhagic Escherichia coli, and Yersinia pestis. PMID:15292162

  10. Identification of the BrRHP1 locus that confers resistance to downy mildew in Chinese cabbage (Brassica rapa ssp. pekinensis) and development of linked molecular markers.

    PubMed

    Kim, Sunggil; Song, Young Ha; Lee, Ji-Yeon; Choi, Su Ryun; Dhandapani, Vignesh; Jang, Chang Soon; Lim, Yong Pyo; Han, Taeho

    2011-11-01

    Inheritance of resistance to downy mildew (Hyaloperonospora parasitica) in Chinese cabbage (Brassica rapa ssp. pekinensis) was studied using inbred parental lines RS1 and SS1 that display strong resistance and severe susceptibility, respectively. F(1), F(2), and BC(1)F(1) populations were evaluated for their responses to downy mildew infection. Resistance to downy mildew was conditioned by a single dominant locus designated BrRHP1. A random amplified polymorphic DNA (RAPD) marker linked to BrRHP1 was identified using bulked segregant analysis and two molecular markers designated BrPERK15A and BrPERK15B were developed. BrPERK15B was polymorphic between the parental lines used to construct the reference linkage map of B. rapa, allowing the mapping of the BrRHP1 locus to the A1 linkage group. Using bacterial artificial chromosome clone sequences anchored to the A1 linkage group, six simple polymerase chain reaction (PCR) markers were developed for use in marker-assisted breeding of downy mildew resistance in Chinese cabbage. Four simple PCR markers flanking the BrRHP1 locus were shown to be collinear with the long-arm region of Arabidopsis chromosome 3. The two closely linked flanking markers delimit the BrRHP1 locus within a 2.2-Mb interval of this Arabidopsis syntenic region.

  11. Identification and mapping of a novel blackleg resistance locus LepR4 in the progenies from Brassica napus × B. rapa subsp. sylvestris.

    PubMed

    Yu, Fengqun; Gugel, Richard K; Kutcher, H Randy; Peng, Gary; Rimmer, S Roger

    2013-02-01

    Blackleg, caused by Leptosphaeria maculans, is one of the most economically important diseases of Brassica napus worldwide. Two blackleg-resistant lines, 16S and 61446, were developed through interspecific hybridization between B. napus and B. rapa subsp. sylvestris and backcrossing to B. napus. Classical genetic analysis demonstrated that a single recessive gene in both lines conferred resistance to L. maculans and that the resistance alleles were allelic. Using BC(1) progeny derived from each resistant plant, this locus was mapped to B. napus linkage group N6 and was flanked by microsatellite markers sN2189b and sORH72a in an interval of about 10 cM, in a region equivalent to about 6 Mb of B. rapa DNA sequence. This new resistance gene locus was designated as LepR4. The two lines were evaluated for resistance to a wide range of L. maculans isolates using cotyledon inoculation tests under controlled environment conditions, and for stem canker resistance in blackleg field nurseries. Results indicated that line 16S, carrying LepR4a, was highly resistant to all isolates tested on cotyledons and had a high level of stem canker resistance under field conditions. Line 61446, carrying LepR4b, was only resistant to some of the isolates tested on cotyledons and was weakly resistant to stem canker under field conditions.

  12. 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

  13. A major locus controlling malondialdehyde content under water stress is associated with Fusarium crown rot resistance in wheat.

    PubMed

    Ma, Jun; Du, Guangyue; Li, Xihuan; Zhang, Caiying; Guo, Jinkao

    2015-10-01

    Malondialdehyde (MDA) is a naturally occurring product of lipid peroxidation and the level of MDA in plant is often used as a parameter to evaluate the damage to plants' cells due to stress. Plant with lower amounts of MDA under drought conditions is generally considered as more tolerant to drought. In this study, a population of recombinant inbred lines was used to map the quantitative trait locus (QTLs) that controlled MDA content under well-watered condition (WW) and water deficit (WD) condition. A major QTL, designated as Qheb.mda-3B, was detected on the long arm of chromosome 3B. Based on interval mapping analysis, Qheb.mda-3B explained 31.5 and 39.0 % of the phenotypic variance under WW and WD conditions, respectively. Qheb.mda-3B was located in the same interval as a previously identified QTL (Qcrs.cpi-3B) that controlled resistance to Fusarium crown rot (FCR), a fungal disease caused by Fusarium species. Three pairs of near-isogenic lines (NILs) previously developed for Qcrs.cpi-3B were found to show significant differences in MDA content under WD condition. These results suggested that same set of genes is likely to be involved in drought tolerance and FCR resistance in wheat.

  14. 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...

  15. 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

  16. 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

  17. 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

  18. Genetic mapping reveals that sinefungin resistance in Toxoplasma gondii is controlled by a putative amino acid transporter locus that can be used as a negative selectable marker.

    PubMed

    Behnke, Michael S; Khan, Asis; Sibley, L David

    2015-02-01

    Quantitative trait locus (QTL) mapping studies have been integral in identifying and understanding virulence mechanisms in the parasite Toxoplasma gondii. In this study, we interrogated a different phenotype by mapping sinefungin (SNF) resistance in the genetic cross between type 2 ME49-FUDR(r) and type 10 VAND-SNF(r). The genetic map of this cross was generated by whole-genome sequencing of the progeny and subsequent identification of single nucleotide polymorphisms (SNPs) inherited from the parents. Based on this high-density genetic map, we were able to pinpoint the sinefungin resistance phenotype to one significant locus on chromosome IX. Within this locus, a single nonsynonymous SNP (nsSNP) resulting in an early stop codon in the TGVAND_290860 gene was identified, occurring only in the sinefungin-resistant progeny. Using CRISPR/CAS9, we were able to confirm that targeted disruption of TGVAND_290860 renders parasites sinefungin resistant. Because disruption of the SNR1 gene confers resistance, we also show that it can be used as a negative selectable marker to insert either a positive drug selection cassette or a heterologous reporter. These data demonstrate the power of combining classical genetic mapping, whole-genome sequencing, and CRISPR-mediated gene disruption for combined forward and reverse genetic strategies in T. gondii.

  19. High-resolution linkage map in the proximity of the host resistance locus Cmv1

    SciTech Connect

    Depatie, C.; Muise, E.; Gros, P.

    1997-01-15

    The mouse chromosome 6 locus Cmv1 controls replication of mouse Cytomegalovirus (MCMV) in the spleen of the infected host. In our effort to clone Cmv1, we have constructed a high-resolution genetic linkage map in the proximity of the gene. For this, a total of 45 DNA markers corresponding to either cloned genes or microsatellites were mapped within a 7.9-cM interval overlapping the Cmv1 region. We have followed the cosegregation of these markers with respect to Cmv1 in a total of 2248 backcross mice from a preexisting interspecific backcross panel of 281 (Mus spretus X C57BL/6J)F1 X C57BL/6J and 2 novel panels of 989 (A/J X C57BL6)F1 X A/J and 978 (BALB/c X C57BL/6J)F1 X BALB/c segregating Cmv1. Combined pedigree analysis allowed us to determine the following gene order and intergene distances (in cM) on the distal region of mouse chromosome 6: D6Mit216-(1.9)-D6Mit336-(2.2)-D6Mit218-(1.0)-D6Mit52-(0.5)-D6Mit194-(0.2)-Nkrp1/D6Mit61/135/257/289/338-(0.4)-Cmv1/Ly49A/D6Mit370-(0.3)-Prp/Kap/D6Mit13/111/219-(0.3)-Tel/D6Mit374/290/220/196/195/110-(1.1)-D6Mit25. Therefore, the minimal genetic interval for Cmv1 of 0.7 cM is defined by 13 tightly linked markers including 2 markers, Ly49A and D6Mit370, that did not show recombination with Cmv1 in 1967 meioses analyzed; the proximal limit of the Cmv1 domain was defined by 8 crossovers between Nkrp1/D6Mit61/135/257/289/338 and Cmv1/Ly49A/D6Mit370, and the distal limit was defined by 5 crossovers between Cmv1/Ly49A/D6Mit370 and Prp/Kap/D6Mit13/111/219. This work demonstrates tight linkage between Cmv1 and genes from the natural killer complex (NKC), such as Nkrp1 and Ly49A suggesting that Cmv1 may represent an NK cell recognition structure encoded in the NKC region. 54 refs., 4 figs., 2 tabs.

  20. Germostatin resistance locus 1 encodes a PHD finger protein involved in auxin-mediated seed dormancy and germination.

    PubMed

    Ye, Yajin; Gong, Ziying; Lu, Xiao; Miao, Deyan; Shi, Jianmin; Lu, Juan; Zhao, Yang

    2016-01-01

    Seed dormancy and germination are important physiological processes during the life cycle of a seed plant. Recently, auxin has been characterized as a positive regulator that functions during seed dormancy and as a negative regulator during germination. Through chemical genetic screenings, we have identified a small molecule, germostatin (GS), which effectively inhibits seed germination in Arabidopsis. GSR1 (germostatin resistance locus 1) encodes a tandem plant homeodomain (PHD) finger protein, identified by screening GS-resistant mutants. Certain PHD fingers of GSR1 are capable of binding unmethylated H3K4, which has been reported as an epigenetic mark of gene transcriptional repression. Biochemical studies show that GSR1 physically interacts with the transcriptional repressor ARF16 and attenuates the intensity of interaction of IAA17/ARF16 by directly interacting with IAA17 to release ARF16. Further results show that axr3-1, arf10 arf16 are hyposensitive to GS, and gsr1 not only resists auxin-mediated inhibition of seed germination but also displays decreased dormancy. We therefore propose that GSR1 may form a co-repressor with ARF16 to regulate seed germination. Besides promoting auxin biosynthesis via upregulating expression of YUCCA1, GS also enhances auxin responses by inducing degradation of DΙΙ-VENUS and upregulating expression of DR5-GFP. In summary, we identified GSR1 as a member of the auxin-mediated seed germination genetic network, and GS, a small non-auxin molecule that specifically acts on auxin-mediated seed germination.

  1. [RAPD-markers linked to the locus for resistance to the race 4 pathogen for black rot, Xanthomonas campestris pv. campestris (Pamm.) Dow., in Brassica rapa L].

    PubMed

    Ignatov, A N; Kuginuki, Y; Suprunova, T P; Pozmogova, G E; Seitova, A M; Dorokhov, D B; Hirai, M

    2000-03-01

    Association between the RAPD markers and the resistance to race 4 of the black rot causative agent was studied in Brassica rapa L. Experiments were carried out using doubled haploid lines, obtained via crosses between the race 4-susceptible fodder turnip and resistant pak-choi, and the F2 progeny of the crosses between the doubled haploid lines with contrasting resistance. The WE(22)980 RAPD marker inherited from the pak-choi and associated with the clubroot susceptibility was also linked to the locus responsible for the resistance to race 4 of Xanthomonas campestris pv. campestris. The two other RAPD markers were linked to susceptibility to black rot. Simultaneous association of the same DNA markers with the resistance/susceptibility to two different obligate pathogens favored the hypothesis on cluster organization of the resistance genes in plants. The markers described can be used in plant breeding and in further investigation of the genetic bases of resistance in plants.

  2. Serratia marcescens arn, a PhoP-regulated locus necessary for polymyxin B resistance.

    PubMed

    Lin, Quei Yen; Tsai, Yi-Lin; Liu, Ming-Che; Lin, Wei-Cheng; Hsueh, Po-Ren; Liaw, Shwu-Jen

    2014-09-01

    Polymyxins, which are increasingly being used to treat infections caused by multidrug-resistant bacteria, perform poorly against Serratia marcescens. To investigate the underlying mechanisms, Tn5 mutagenesis was performed and two mutants exhibiting increased polymyxin B (PB) susceptibility were isolated. The mutants were found to have Tn5 inserted into the arnB and arnC genes. In other bacteria, arnB and arnC belong to the seven-gene arn operon, which is involved in lipopolysaccharide (LPS) modification. LPSs of arn mutants had greater PB-binding abilities than that of wild-type LPS. Further, we identified PhoP, a bacterial two-component response regulator, as a regulator of PB susceptibility in S. marcescens. By the reporter assay, we found PB- and low-Mg2+-induced expression of phoP and arn in the wild-type strain but not in the phoP mutant. Complementation of the phoP mutant with the full-length phoP gene restored the PB MIC and induction by PB and low Mg2+ levels, as in the wild type. An electrophoretic mobility shift assay (EMSA) further demonstrated that PhoP bound directly to the arn promoter. The PB challenge test confirmed that pretreatment with PB and low Mg2+ levels protected S. marcescens from a PB challenge in the wild-type strain but not in the phoP mutant. Real-time reverse transcriptase-PCR also indicated that PB serves as a signal to regulate expression of ugd, a gene required for LPS modification, in S. marcescens through a PhoP-dependent pathway. Finally, we found that PB-resistant clinical isolates displayed greater expression of arnA upon exposure to PB than did susceptible isolates. This is the first report to describe the role of S. marcescens arn in PB resistance and its modulation by PB and Mg2+ through the PhoP protein.

  3. Rapid reversion from monomer to dimer regenerates the ultraviolet-B photoreceptor UV RESISTANCE LOCUS8 in intact Arabidopsis plants.

    PubMed

    Heilmann, Monika; Jenkins, Gareth I

    2013-01-01

    Arabidopsis (Arabidopsis thaliana) UV RESISTANCE LOCUS8 (UVR8) is a photoreceptor that specifically mediates photomorphogenic responses to ultraviolet (UV)-B in plants. UV-B photoreception induces the conversion of the UVR8 dimer into a monomer that interacts with the CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1) protein to regulate gene expression. However, it is not known how the dimeric photoreceptor is regenerated in plants. Here, we show, by using inhibitors of protein synthesis and degradation via the proteasome, that the UVR8 dimer is not regenerated by rapid de novo synthesis following destruction of the monomer. Rather, regeneration occurs by reversion from the monomer to the dimer. However, regeneration of dimeric UVR8 in darkness following UV-B exposure occurs much more rapidly in vivo than in vitro with illuminated plant extracts or purified UVR8, indicating that rapid regeneration requires intact cells. Rapid dimer regeneration in vivo requires protein synthesis, the presence of a carboxyl-terminal 27-amino acid region of UVR8, and the presence of COP1, which is known to interact with the carboxyl-terminal region. However, none of these factors can account fully for the difference in regeneration kinetics in vivo and in vitro, indicating that additional proteins or processes are involved in UVR8 dimer regeneration in vivo.

  4. Multiple roles for UV RESISTANCE LOCUS8 in regulating gene expression and metabolite accumulation in Arabidopsis under solar ultraviolet radiation.

    PubMed

    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

    2013-02-01

    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.

  5. 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.

  6. A Narrow Quantitative Trait Locus in C. elegans Coordinately Affects Longevity, Thermotolerance, and Resistance to Paraquat

    PubMed Central

    Vertino, Anthony; Ayyadevara, Srinivas; Thaden, John J.; Reis, Robert J. Shmookler

    2011-01-01

    By linkage mapping of quantitative trait loci, we previously identified at least 11 natural genetic variants that significantly modulate Caenorhabditis elegans life-span (LS), many of which would have eluded discovery by knock-down or mutation screens. A region on chromosome IV between markers stP13 and stP35 had striking effects on longevity in three inter-strain crosses (each P < 10−9). In order to define the limits of that interval, we have now constructed two independent lines by marker-based selection during 20 backcross generations, isolating the stP13–stP35 interval from strain Bergerac-BO in a CL2a background. These congenic lines differed significantly from CL2a in LS, assayed in two environments (each P < 0.001). We then screened for exchange of flanking markers to isolate recombinants that partition this region, because fine-mapping the boundaries for overlapping heteroallelic spans can greatly narrow the implicated interval. Recombinants carrying the CL2a allele at stP35 were consistently long-lived compared to those retaining the Bergerac-BO allele (P < 0.001), and more resistant to temperature elevation and paraquat (each ∼1.7-fold, P < 0.0001), but gained little protection from ultraviolet or peroxide stresses. Two rounds of recombinant screening, followed by fine-mapping of break-points and survival testing, narrowed the interval to 0.18 Mb (13.35–13.53 Mb) containing 26 putative genes and six small-nuclear RNAs – a manageable number of targets for functional assessment. PMID:22303358

  7. Evolutionary changes in gene expression, coding sequence and copy-number at the Cyp6g1 locus contribute to resistance to multiple insecticides in Drosophila.

    PubMed

    Harrop, Thomas W R; Sztal, Tamar; Lumb, Christopher; Good, Robert T; Daborn, Phillip J; Batterham, Philip; Chung, Henry

    2014-01-01

    Widespread use of insecticides has led to insecticide resistance in many populations of insects. In some populations, resistance has evolved to multiple pesticides. In Drosophila melanogaster, resistance to multiple classes of insecticide is due to the overexpression of a single cytochrome P450 gene, Cyp6g1. Overexpression of Cyp6g1 appears to have evolved in parallel in Drosophila simulans, a sibling species of D. melanogaster, where it is also associated with insecticide resistance. However, it is not known whether the ability of the CYP6G1 enzyme to provide resistance to multiple insecticides evolved recently in D. melanogaster or if this function is present in all Drosophila species. Here we show that duplication of the Cyp6g1 gene occurred at least four times during the evolution of different Drosophila species, and the ability of CYP6G1 to confer resistance to multiple insecticides exists in D. melanogaster and D. simulans but not in Drosophila willistoni or Drosophila virilis. In D. virilis, which has multiple copies of Cyp6g1, one copy confers resistance to DDT and another to nitenpyram, suggesting that the divergence of protein sequence between copies subsequent to the duplication affected the activity of the enzyme. All orthologs tested conferred resistance to one or more insecticides, suggesting that CYP6G1 had the capacity to provide resistance to anthropogenic chemicals before they existed. Finally, we show that expression of Cyp6g1 in the Malpighian tubules, which contributes to DDT resistance in D. melanogaster, is specific to the D. melanogaster-D. simulans lineage. Our results suggest that a combination of gene duplication, regulatory changes and protein coding changes has taken place at the Cyp6g1 locus during evolution and this locus may play a role in providing resistance to different environmental toxins in different Drosophila species.

  8. Evolutionary Changes in Gene Expression, Coding Sequence and Copy-Number at the Cyp6g1 Locus Contribute to Resistance to Multiple Insecticides in Drosophila

    PubMed Central

    Harrop, Thomas W. R.; Sztal, Tamar; Lumb, Christopher; Good, Robert T.; Daborn, Phillip J.; Batterham, Philip; Chung, Henry

    2014-01-01

    Widespread use of insecticides has led to insecticide resistance in many populations of insects. In some populations, resistance has evolved to multiple pesticides. In Drosophila melanogaster, resistance to multiple classes of insecticide is due to the overexpression of a single cytochrome P450 gene, Cyp6g1. Overexpression of Cyp6g1 appears to have evolved in parallel in Drosophila simulans, a sibling species of D. melanogaster, where it is also associated with insecticide resistance. However, it is not known whether the ability of the CYP6G1 enzyme to provide resistance to multiple insecticides evolved recently in D. melanogaster or if this function is present in all Drosophila species. Here we show that duplication of the Cyp6g1 gene occurred at least four times during the evolution of different Drosophila species, and the ability of CYP6G1 to confer resistance to multiple insecticides exists in D. melanogaster and D. simulans but not in Drosophila willistoni or Drosophila virilis. In D. virilis, which has multiple copies of Cyp6g1, one copy confers resistance to DDT and another to nitenpyram, suggesting that the divergence of protein sequence between copies subsequent to the duplication affected the activity of the enzyme. All orthologs tested conferred resistance to one or more insecticides, suggesting that CYP6G1 had the capacity to provide resistance to anthropogenic chemicals before they existed. Finally, we show that expression of Cyp6g1 in the Malpighian tubules, which contributes to DDT resistance in D. melanogaster, is specific to the D. melanogaster–D. simulans lineage. Our results suggest that a combination of gene duplication, regulatory changes and protein coding changes has taken place at the Cyp6g1 locus during evolution and this locus may play a role in providing resistance to different environmental toxins in different Drosophila species. PMID:24416303

  9. Molecular characterization of the Pseudomonas syringae pv. pisi plasmid-borne avirulence gene avrPpiB which matches the R3 resistance locus in pea.

    PubMed

    Cournoyer, B; Sharp, J D; Astuto, A; Gibbon, M J; Taylor, J D; Vivian, A

    1995-01-01

    An avirulence gene (designated avrPpiB) from race 3 of Pseudomonas syringae pv. pisi was cloned and sequenced. The gene corresponded to a single open reading frame of 831 nt identified by transposon mutagenesis and subcloning. This ORF encodes a predicted hydrophilic protein of 276 amino acids (MW 31,300). It effects the expression of a resistance mechanism governed by a single genetic locus in pea. Cosegregation of resistance at the R3 locus of pea was observed towards race 3 and a transconjugant carrying the cloned avrPpiB gene according to the predicted 3:1 ratio of resistant:susceptible F2 progeny from a cross between Jade (R3 R3) and Kelvedon Wonder (rr) cultivars. DNA hybridization studies showed avrPpiB to be plasmid-borne in race 3 and suggested the presence of other alleles on one of the endogenous plasmids of races 1 and 7. Disruption of the avrPpiB allele of race 1 and its complementation confirmed its behavior towards pea cultivars expressing the R3 locus. Homologs of avrPpiB were detected in P. syringae pv. phaseolicola, P. syringae pv. maculicola, and P. syringae pv. tomato. The presence of avrPpiB homologs in P. syringae pv. phaseolicola does not match any gene-for-gene pattern of interaction with bean cultivars.

  10. 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.

  11. Genetic mapping identifies a major locus spanning P450 clusters associated with pyrethroid resistance in kdr-free Anopheles arabiensis from Chad.

    PubMed

    Witzig, C; Parry, M; Morgan, J C; Irving, H; Steven, A; Cuamba, N; Kerah-Hinzoumbé, C; Ranson, H; Wondji, C S

    2013-04-01

    Prevention of malaria transmission throughout much of Africa is dependent on bednets that are impregnated with pyrethroid insecticides. Anopheles arabiensis is the major malaria vector in Chad and efforts to control this vector are threatened by the emergence of pyrethroid resistance. WHO bioassays revealed that An. arabiensis from Ndjamena is resistant to pyrethroids and dichlorodiphenyltrichloroethane (DDT) but fully susceptible to carbamates and organophosphates. No 1014F or 1014S kdr alleles were detected in this population. To determine the mechanisms that are responsible for resistance, genetic crosses were established between the Ndja strain and an insecticide susceptible population from Mozambique. Resistance was inherited as an autosomal trait and quantitative trait locus (QTL) mapping identified a single major locus on chromosome 2R, which explained 24.4% of the variance in resistance. This QTL is enriched in P450 genes including 25 cytochrome P450s in total. One of these, Cyp6p4 is 22-fold upregulated in the Ndja strain compared with the susceptible. Piperonyl butoxide (PBO) synergist and biochemical assays further support a role for P450s in conferring pyrethroid resistance in this population.

  12. 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

  13. 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

  14. 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

  15. 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.

  16. Analysis of a Plant Complex Resistance Gene Locus Underlying Immune-Related Hybrid Incompatibility and Its Occurrence in Nature

    PubMed Central

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

    2014-01-01

    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

  17. 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

  18. Monoubiquitination of Histone 2B at the Disease Resistance Gene Locus Regulates Its Expression and Impacts Immune Responses in Arabidopsis1[C][W][OPEN

    PubMed Central

    Zou, Baohong; Yang, Dong-Lei; Shi, Zhenying; Dong, Hansong; Hua, Jian

    2014-01-01

    Disease resistance (R) genes are key components in plant immunity. Here, we show that Arabidopsis (Arabidopsis thaliana) E3 ubiquitin ligase genes HISTONE MONOUBIQUITINATION1 (HUB1) and HUB2 regulate the expression of R genes SUPPRESSOR OF npr1-1, CONSTITUTIVE1 (SNC1) and RESISTANCE TO PERONOSPORA PARASITICA4. An increase of SNC1 expression induces constitutive immune responses in the bonzai1 (bon1) mutant, and the loss of HUB1 or HUB2 function reduces SNC1 up-regulation and suppresses the bon1 autoimmune phenotypes. HUB1 and HUB2 mediate histone 2B (H2B) monoubiquitination directly at the SNC1 R gene locus to regulate its expression. In addition, SNC1 and HUB1 transcripts are moderately up-regulated by pathogen infection, and H2B monoubiquitination at SNC1 is enhanced by pathogen infection. Together, this study indicates that H2B monoubiquitination at the R gene locus regulates its expression and that this histone modification at the R gene locus has an impact on immune responses in plants. PMID:24664204

  19. Physical organization of mixed protease inhibitor gene clusters, coordinated expression and association with resistance to late blight at the StKI locus on potato chromosome III.

    PubMed

    Odeny, Damaris Achieng; Stich, Benjamin; Gebhardt, Christiane

    2010-12-01

    Protease inhibitors (PIs) play a role in plant defence against pests and pathogens as well as in plant development. Potato (Solanum tuberosum) contains abundant levels of diverse PIs. Most potato Kunitz-type inhibitor (KTI) genes map to the StKI locus on potato chromosome III, which is linked to a quantitative trait locus (QTL) for resistance to Phytophthora infestans. To elucidate the physical organization of PIs at the StKI locus, we screened bacterial artificial chromosome (BAC) libraries with KTI probes. Ten different clones were selected, sequenced and annotated. Of 100 putative genes, 22 corresponded to five PI classes. Expression analysis by quantitative real-time PCR (qRT-PCR) using PI class-specific primers in different tissues of the tetraploid potato cultivars 'Nikita' and 'Baltica' revealed different transcript levels, depending on PI type and genotype. During the compatible interaction with a complex race of P. infestans, four PI classes showed coordinated expression over 3 d after infection, a strong decrease in infected leaves and a transient induction in systemic leaves. Basal transcript levels in non-infected leaves differed strongly between the two genotypes examined. Two microsatellite markers located within the PI gene cluster were associated with resistance to P. infestans in a population of potato varieties and breeding clones. PMID:20716067

  20. 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

  1. 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

  2. Modeling rare earth complexes: Sparkle/PM3 parameters for thulium(III)

    NASA Astrophysics Data System (ADS)

    Freire, Ricardo O.; Rocha, Gerd B.; Simas, Alfredo M.

    2006-07-01

    The Sparkle model, recently defined for Tm(III) within AM1 [R.O. Freire, G.B. Rocha, A.M. Simas, Chem. Phys. Lett. 411 (2005) 61], is now extended to PM3. For the same 15 complexes previously used, the Sparkle/PM3 unsigned mean error, for all interatomic distances between the Tm(III) ion and the directly coordinating oxygen or nitrogen atoms, is 0.08 Å, a level of accuracy equivalent to the Sparkle/AM1 figure of 0.07 Å, as well as to results from present day ab initio effective core potential calculations. The results thus indicate that both Sparkle/AM1 and Sparkle/PM3 models may prove useful for luminescent Tm(III) complex design.

  3. The Ity/Lsh/Bcg locus: natural resistance to infection with intracellular parasites is abrogated by disruption of the Nramp1 gene

    PubMed Central

    1995-01-01

    In mice, natural resistance or susceptibility to infection with intracellular parasites is determined by a locus or group of loci on chromosome 1, designated Bcg, Lsh, and Ity, which controls early microbial replication in reticuloendothelial organs. We have identified by positional cloning a candidate gene for Bcg, Nramp1, which codes for a novel macrophage-specific membrane transport protein. We have created a mouse mutant bearing a null allele at Nramp1, and we have analyzed the effect of such a mutation on natural resistance to infection. Targeted disruption of Nramp1 has pleiotropic effects on natural resistance to infection with intracellular parasites, as it eliminated resistance to Mycobacterium bovis, Leishmania donovani, and lethal Salmonella typhimurium infection, establishing that Nramp1, Bcg, Lsh, and Ity are the same locus. Comparing the profiles of parasite replication in control and Nramp1-/- mice indicated that the Nramp1Asp169 allele of BcgS inbred strains is a null allele, pointing to a critical role of this residue in the mechanism of action of the protein. Despite their inability to control parasite growth in the early nonimmune phase of the infection, Nramp1-/- mutants can overcome the infection in the late immune phase, suggesting that Nramp1 plays a key role only in the early part of the macrophage-parasite interaction and may function by a cytocidal or cytostatic mechanism distinct from those expressed by activated macrophages. PMID:7650477

  4. 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

  5. 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

  6. 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.

  7. Molecular Analysis of the embCAB Locus and embR Gene Involved in Ethambutol Resistance in Clinical Isolates of Mycobacterium tuberculosis in France

    PubMed Central

    Sougakoff, Wladimir; Bernard, Christine; Petrou, Matthieu; Adeyema, Karine; Pham, Anne; Amy de la Breteque, Diane; Vallet, Marine; Jarlier, Vincent; Sola, Christophe; Veziris, Nicolas

    2015-01-01

    Modification of codon 306 in embB is regarded as the main mechanism leading to ethambutol (ETB) resistance in clinical isolates of Mycobacterium tuberculosis. However, numerous mutations elsewhere in the embCAB locus and in embR, a putative transcriptional activator of this locus, have been reported to be involved in ETB resistance. Here, we investigated the diversity of nucleotide variations observed in embCAB and embR in M. tuberculosis complex isolates from France. These regions were sequenced in 71 ETB-resistant (ETB-R) and 60 ETB-susceptible (ETB-S) clinical isolates of known phylogenetic lineages. The 131 isolates had 12 mutations corresponding to phylogenetic markers. Among the 60 ETB-S isolates, only 3 (5%) had nonsynonymous mutations that were not phylogenetic markers. Among the 71 ETB-R isolates, 98% had mutations in embCAB that likely contribute to ETB resistance: 70% had mutations located in embB codon 306, 406, or 497; 13% had mutations located outside these three positions between codons 296 and 426; and 15% had mutations corresponding to mutations in the embC-embA intergenic region. We found a strong association between resistance to ETB and the presence of mutations in embB and the embC-embA intergenic region (P < 0.001). In contrast, the mutations detected in embC and embA were not involved in ETB resistance, and no mutation was detected in embR. These results strongly suggest that the sensitivity of diagnostic assays for detecting ETB resistance based on testing of embB codon 306 can be increased by testing of the embB region between codons 296 and 497 and by including the embC-embA intergenic region between positions −8 and −21. PMID:26033726

  8. INK4 locus of the tumor-resistant rodent, the naked mole rat, expresses a functional p15/p16 hybrid isoform.

    PubMed

    Tian, Xiao; Azpurua, Jorge; Ke, Zhonghe; Augereau, Adeline; Zhang, Zhengdong D; Vijg, Jan; Gladyshev, Vadim N; Gorbunova, Vera; Seluanov, Andrei

    2015-01-27

    The naked mole rat (Heterocephalus glaber) is a long-lived and tumor-resistant rodent. Tumor resistance in the naked mole rat is mediated by the extracellular matrix component hyaluronan of very high molecular weight (HMW-HA). HMW-HA triggers hypersensitivity of naked mole rat cells to contact inhibition, which is associated with induction of the INK4 (inhibitors of cyclin dependent kinase 4) locus leading to cell-cycle arrest. The INK4a/b locus is among the most frequently mutated in human cancer. This locus encodes three distinct tumor suppressors: p15(INK4b), p16(INK4a), and ARF (alternate reading frame). Although p15(INK4b) has its own ORF, p16(INK4a) and ARF share common second and third exons with alternative reading frames. Here, we show that, in the naked mole rat, the INK4a/b locus encodes an additional product that consists of p15(INK4b) exon 1 joined to p16(INK4a) exons 2 and 3. We have named this isoform pALT(INK4a/b) (for alternative splicing). We show that pALT(INK4a/b) is present in both cultured cells and naked mole rat tissues but is absent in human and mouse cells. Additionally, we demonstrate that pALT(INK4a/b) expression is induced during early contact inhibition and upon a variety of stresses such as UV, gamma irradiation-induced senescence, loss of substrate attachment, and expression of oncogenes. When overexpressed in naked mole rat or human cells, pALT(INK4a/b) has stronger ability to induce cell-cycle arrest than either p15(INK4b) or p16(INK4a). We hypothesize that the presence of the fourth product, pALT(INK4a/b) of the INK4a/b locus in the naked mole rat, contributes to the increased resistance to tumorigenesis of this species.

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

    PubMed Central

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

    2015-01-01

    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

  10. The Brassica napus receptor-like protein RLM2 is encoded by a second allele of the LepR3/Rlm2 blackleg resistance locus.

    PubMed

    Larkan, Nicholas J; Ma, Lisong; Borhan, Mohammad Hossein

    2015-09-01

    Leucine-rich repeat receptor-like proteins (LRR-RLPs) are highly adaptable parts of the signalling apparatus for extracellular detection of plant pathogens. Resistance to blackleg disease of Brassica spp. caused by Leptosphaeria maculans is largely governed by host race-specific R-genes, including the LRR-RLP gene LepR3. The blackleg resistance gene Rlm2 was previously mapped to the same genetic interval as LepR3. In this study, the LepR3 locus of the Rlm2 Brassica napus line 'Glacier DH24287' was cloned, and B. napus transformants were analysed for recovery of the Rlm2 phenotype. Multiple B. napus, B. rapa and B. juncea lines were assessed for sequence variation at the locus. Rlm2 was found to be an allelic variant of the LepR3 LRR-RLP locus, conveying race-specific resistance to L. maculans isolates harbouring AvrLm2. Several defence-related LRR-RLPs have previously been shown to associate with the RLK SOBIR1 to facilitate defence signalling. Bimolecular fluorescence complementation (BiFC) and co-immunoprecipitation of RLM2-SOBIR1 studies revealed that RLM2 interacts with SOBIR1 of Arabidopsis thaliana when co-expressed in Nicotiana benthamiana. The interaction of RLM2 with AtSOBIR1 is suggestive of a conserved defence signalling pathway between B. napus and its close relative A. thaliana.

  11. 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 Central

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

    2010-01-01

    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. Electronic supplementary material The online version of this article (doi:10.1007/s00122-010-1472-9) contains supplementary material, which is available to authorized users. PMID:21049265

  12. Phenotypic assortment in Tetrahymena thermophila: assortment kinetics of antibiotic-resistance markers, tsA, death, and the highly amplified rDNA locus.

    PubMed

    Merriam, E V; Bruns, P J

    1988-10-01

    Phenotypic assortment in Tetrahymena thermophila results from random distribution of alleles during amitotic division of the macronucleus. The rate of assortment is dependent on input ratio and the number of assorting units. The assortment of the antibiotic resistance markers Chx, Mpr and gal was determined and is consistent for each with the model of 45 assorting chromosomes. The gene tsA (previously ts-1) shows normal assortment, in contrast to previous reports. A mutation in the highly amplified ribosomal locus (rdnA2) assorts as if present at only 45 copies. Death of clones occurred at a rate consistent with assortment for a single gene.

  13. 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

  14. 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.

  15. 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

  16. Generation of mastitis resistance in cows by targeting human lysozyme gene to β-casein locus using zinc-finger nucleases.

    PubMed

    Liu, Xu; Wang, Yongsheng; Tian, Yuchen; Yu, Yuan; Gao, Mingqing; Hu, Guangdong; Su, Feng; Pan, Shaohui; Luo, Yan; Guo, Zekun; Quan, Fusheng; Zhang, Yong

    2014-04-01

    Mastitis costs the dairy industry billions of dollars annually and is the most consequential disease of dairy cattle. Transgenic cows secreting an antimicrobial peptide demonstrated resistance to mastitis. The combination of somatic cell gene targeting and nuclear transfer provides a powerful method to produce transgenic animals. Recent studies found that a precisely placed double-strand break induced by engineered zinc-finger nucleases (ZFNs) stimulated the integration of exogenous DNA stretches into a pre-determined genomic location, resulting in high-efficiency site-specific gene addition. Here, we used ZFNs to target human lysozyme (hLYZ) gene to bovine β-casein locus, resulting in hLYZ knock-in of approximately 1% of ZFN-treated bovine fetal fibroblasts (BFFs). Gene-targeted fibroblast cell clones were screened by junction PCR amplification and Southern blot analysis. Gene-targeted BFFs were used in somatic cell nuclear transfer. In vitro assays demonstrated that the milk secreted by transgenic cows had the ability to kill Staphylococcus aureus. We report the production of cloned cows carrying human lysozyme gene knock-in β-casein locus using ZFNs. Our findings open a unique avenue for the creation of transgenic cows from genetic engineering by providing a viable tool for enhancing resistance to disease and improving the health and welfare of livestock.

  17. Generation of mastitis resistance in cows by targeting human lysozyme gene to β-casein locus using zinc-finger nucleases

    PubMed Central

    Liu, Xu; Wang, Yongsheng; Tian, Yuchen; Yu, Yuan; Gao, Mingqing; Hu, Guangdong; Su, Feng; Pan, Shaohui; Luo, Yan; Guo, Zekun; Quan, Fusheng; Zhang, Yong

    2014-01-01

    Mastitis costs the dairy industry billions of dollars annually and is the most consequential disease of dairy cattle. Transgenic cows secreting an antimicrobial peptide demonstrated resistance to mastitis. The combination of somatic cell gene targeting and nuclear transfer provides a powerful method to produce transgenic animals. Recent studies found that a precisely placed double-strand break induced by engineered zinc-finger nucleases (ZFNs) stimulated the integration of exogenous DNA stretches into a pre-determined genomic location, resulting in high-efficiency site-specific gene addition. Here, we used ZFNs to target human lysozyme (hLYZ) gene to bovine β-casein locus, resulting in hLYZ knock-in of approximately 1% of ZFN-treated bovine fetal fibroblasts (BFFs). Gene-targeted fibroblast cell clones were screened by junction PCR amplification and Southern blot analysis. Gene-targeted BFFs were used in somatic cell nuclear transfer. In vitro assays demonstrated that the milk secreted by transgenic cows had the ability to kill Staphylococcus aureus. We report the production of cloned cows carrying human lysozyme gene knock-in β-casein locus using ZFNs. Our findings open a unique avenue for the creation of transgenic cows from genetic engineering by providing a viable tool for enhancing resistance to disease and improving the health and welfare of livestock. PMID:24552841

  18. Identification of a c-di-GMP-regulated polysaccharide locus governing stress resistance and biofilm and rugose colony formation in Vibrio vulnificus.

    PubMed

    Guo, Yunzhi; Rowe-Magnus, Dean A

    2010-03-01

    As an etiological agent of bacterial sepsis and wound infections, Vibrio vulnificus is unique among the Vibrionaceae. Its continued environmental persistence and transmission are bolstered by its ability to colonize shellfish, form biofilms on various marine biotic surfaces, and generate a morphologically and physiologically distinct rugose (R) variant that yields profuse biofilms. Here, we identify a c-di-GMP-regulated locus (brp, for biofilm and rugose polysaccharide) and two transcription factors (BrpR and BrpT) that regulate these physiological responses. Disruption of glycosyltransferases within the locus or either regulator abated the inducing effect of c-di-GMP on biofilm formation, rugosity, and stress resistance. The same lesions, or depletion of intracellular c-di-GMP levels, abrogated these phenotypes in the R variant. The parental and brp mutant strains formed only scant monolayers on glass surfaces and oyster shells, and although the R variant formed expansive biofilms, these were of limited depth. Dramatic vertical expansion of the biofilm structure was observed in the parental strain and R variant, but not the brp mutants, when intracellular c-di-GMP levels were elevated. Hence, the brp-encoded polysaccharide is important for surface colonization and stress resistance in V. vulnificus, and its expression may control how the bacteria switch from a planktonic lifestyle to colonizing shellfish to invading human tissue.

  19. 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...

  20. 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...

  1. 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.

  2. 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

  3. 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.

  4. 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

  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. Identification and mapping of a third blackleg resistance locus in Brassica napus derived from B. rapa subsp. sylvestris.

    PubMed

    Yu, Fengqun; Lydiate, Derek J; Rimmer, S Roger

    2008-01-01

    The spectrum of resistance to isolates of Leptosphaeria maculans and the map location of a new blackleg resistance gene found in the canola cultivar Brassica napus 'Surpass 400' are described. Two blackleg resistance genes, LepR1 and LepR2, from B. rapa subsp. sylvestris and introgressed in B. napus were identified previously. 'Surpass 400' also has blackleg resistance introgressed from B. rapa subsp. sylvestris. Using 31 diverse isolates of L. maculans, the disease reaction of 'Surpass 400' was compared with those of the resistant breeding lines AD9 (which contains LepR1), AD49 (which contains LepR2), and MC1-8 (which contains both LepR1 and LepR2). The disease reaction on 'Surpass 400' was different from those observed on AD9 and MC1-8, indicating that 'Surpass 400' carries neither LepR1 nor both LepR1 and LepR2 in combination. Disease reactions of 'Surpass 400' to most of the isolates tested were indistinguishable from those of AD49, which suggested 'Surpass 400' might contain LepR2 or a similar resistance gene. Classical genetic analysis of F1 and BC1 plants showed that a dominant allele conferred resistance to isolates of L. maculans in 'Surpass 400'. The resistance gene, which mapped to B. napus linkage group N10 in an interval of 2.9 cM flanked by microsatellite markers sR12281a and sN2428Rb and 11.7 cM below LepR2, was designated LepR3. A 9 cM region of the B. napus genome containing LepR3 was found to be syntenic with a segment of Arabidopsis chromosome 5.

  7. 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

  8. Allele-specific CAPS markers based on point mutations in resistance alleles at the pvr1 locus encoding eIF4E in Capsicum.

    PubMed

    Yeam, Inhwa; Kang, Byoung-Cheorl; Lindeman, Wouter; Frantz, James D; Faber, Nanne; Jahn, Molly M

    2005-12-01

    Marker-assisted selection has been widely implemented in crop breeding and can be especially useful in cases where the traits of interest show recessive or polygenic inheritance and/or are difficult or impossible to select directly. Most indirect selection is based on DNA polymorphism linked to the target trait, resulting in error when the polymorphism recombines away from the mutation responsible for the trait and/or when the linkage between the mutation and the polymorphism is not conserved in all relevant genetic backgrounds. In this paper, we report the generation and use of molecular markers that define loci for selection using cleaved amplified polymorphic sequences (CAPS). These CAPS markers are based on nucleotide polymorphisms in the resistance gene that are perfectly correlated with disease resistance, the trait of interest. As a consequence, the possibility that the marker will not be linked to the trait in all backgrounds or that the marker will recombine away from the trait is eliminated. We have generated CAPS markers for three recessive viral resistance alleles used widely in pepper breeding, pvr1, pvr1 (1), and pvr1 (2). These markers are based on single nucleotide polymorphisms (SNPs) within the coding region of the pvr1 locus encoding an eIF4E homolog on chromosome 3. These three markers define a system of indirect selection for potyvirus resistance in Capsicum based on genomic sequence. We demonstrate the utility of this marker system using commercially significant germplasm representing two Capsicum species. Application of these markers to Capsicum improvement is discussed.

  9. Diversity among strains of Pseudomonas aeruginosa from manure and soil, evaluated by multiple locus variable number tandem repeat analysis and antibiotic resistance profiles.

    PubMed

    Youenou, Benjamin; Brothier, Elisabeth; Nazaret, Sylvie

    2014-01-01

    The results of a multiple locus variable number of tandem repeat (VNTR) analysis (MLVA)-based study designed to understand the genetic diversity of soil and manure-borne Pseudomonas aeruginosa isolates, and the relationship between these isolates and a set of clinical and environmental isolates, are hereby reported. Fifteen described VNTR markers were first selected, and 62 isolates recovered from agricultural and industrial soils in France and Burkina Faso, and from cattle and horse manure, along with 26 snake-related isolates and 17 environmental and clinical isolates from international collections, were genotyped. Following a comparison with previously published 9-marker MLVA schemes, an optimal 13-marker MLVA scheme (MLVA13-Lyon) was identified that was found to be the most efficient, as it showed high typability (90%) and high discriminatory power (0.987). A comparison of MLVA with PFGE for typing of the snake-related isolates confirmed the MLVA13-Lyon scheme to be a robust method for quickly discriminating and inferring genetic relatedness among environmental isolates. The 62 isolates displayed wide diversity, since 41 MLVA types (i.e. MTs) were observed, with 26 MTs clustered in 10 MLVA clonal complexes (MCs). Three and eight MCs were found among soil and manure isolates, respectively. Only one MC contained both soil and manure-borne isolates. No common MC was observed between soil and manure-borne isolates and the snake-related or environmental and clinical isolates. Antibiotic resistance profiles were performed to determine a potential link between resistance properties and the selective pressure that might be present in the various habitats. Except for four soil and manure isolates resistant to ticarcillin and ticarcillin/clavulanic acid and one isolate from a hydrocarbon-contaminated soil resistant to imipenem, all environmental isolates showed wild-type antibiotic profiles.

  10. 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.

  11. Rapid identification of international multidrug-resistant Pseudomonas aeruginosa clones by multiple-locus variable number of tandem repeats analysis and investigation of their susceptibility to lytic bacteriophages.

    PubMed

    Larché, Jérôme; Pouillot, Flavie; Essoh, Christiane; Libisch, Balázs; Straut, Monica; Lee, Je Chul; Soler, Charles; Lamarca, Richard; Gleize, Elodie; Gabard, Jérôme; Vergnaud, Gilles; Pourcel, Christine

    2012-12-01

    The objective of this study was to determine the genetic diversity of multidrug-resistant (MDR) Pseudomonas aeruginosa strains isolated over a period of 12 months in two French hospitals and to test their susceptibility to bacteriophages. A total of 47 MDR isolates recovered from hospitalized patients were genotyped using multiple-locus variable number of tandem repeats analysis. The genotypes were distributed into five clones (including 19, 5, 5, 3, and 3 isolates, respectively) and 12 singletons. Comparison to 77 MDR strains from three other countries, and MLST analysis of selected isolates showed the predominance of international MDR clones. The larger clone, CC235, contained 59 isolates displaying different antibiotic resistance mechanisms, including the presence of the GES1, VIM-2, VIM-4, and IMP-1 β-lactamases. Three newly isolated P. aeruginosa bacteriophages were found to lyse 42 of the 44 analyzed strains, distributed into the different clonal complexes. This pilot study suggests that systematic genotyping of P. aeruginosa MDR strains could improve our epidemiological understanding of transmission at both the local (hospital) and the national level and that phage therapy could be an alternative or a complementary treatment to antibiotics for treating MDR-infected patients.

  12. Rapid Identification of International Multidrug-Resistant Pseudomonas aeruginosa Clones by Multiple-Locus Variable Number of Tandem Repeats Analysis and Investigation of Their Susceptibility to Lytic Bacteriophages

    PubMed Central

    Larché, Jérôme; Pouillot, Flavie; Essoh, Christiane; Libisch, Balázs; Straut, Monica; Lee, Je Chul; Soler, Charles; Lamarca, Richard; Gleize, Elodie; Gabard, Jérôme; Vergnaud, Gilles

    2012-01-01

    The objective of this study was to determine the genetic diversity of multidrug-resistant (MDR) Pseudomonas aeruginosa strains isolated over a period of 12 months in two French hospitals and to test their susceptibility to bacteriophages. A total of 47 MDR isolates recovered from hospitalized patients were genotyped using multiple-locus variable number of tandem repeats analysis. The genotypes were distributed into five clones (including 19, 5, 5, 3, and 3 isolates, respectively) and 12 singletons. Comparison to 77 MDR strains from three other countries, and MLST analysis of selected isolates showed the predominance of international MDR clones. The larger clone, CC235, contained 59 isolates displaying different antibiotic resistance mechanisms, including the presence of the GES1, VIM-2, VIM-4, and IMP-1 β-lactamases. Three newly isolated P. aeruginosa bacteriophages were found to lyse 42 of the 44 analyzed strains, distributed into the different clonal complexes. This pilot study suggests that systematic genotyping of P. aeruginosa MDR strains could improve our epidemiological understanding of transmission at both the local (hospital) and the national level and that phage therapy could be an alternative or a complementary treatment to antibiotics for treating MDR-infected patients. PMID:22985882

  13. 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...

  14. 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...

  15. 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...

  16. 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

  17. 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.

  18. Genomic Analysis Reveals a Common Breakpoint in Amplifications of the Plasmodium vivax Multidrug Resistance 1 Locus in Thailand

    PubMed Central

    Auburn, Sarah; Serre, David; Pearson, Richard D.; Amato, Roberto; Sriprawat, Kanlaya; To, Sheren; Handayuni, Irene; Suwanarusk, Rossarin; Russell, Bruce; Drury, Eleanor; Stalker, Jim; Miotto, Olivo; Kwiatkowski, Dominic P.; Nosten, Francois; Price, Ric N.

    2016-01-01

    In regions of coendemicity for Plasmodium falciparum and Plasmodium vivax where mefloquine is used to treat P. falciparum infection, drug pressure mediated by increased copy numbers of the multidrug resistance 1 gene (pvmdr1) may select for mefloquine-resistant P. vivax. Surveillance is not undertaken routinely owing in part to methodological challenges in detection of gene amplification. Using genomic data on 88 P. vivax samples from western Thailand, we identified pvmdr1 amplification in 17 isolates, all exhibiting tandem copies of a 37.6–kilobase pair region with identical breakpoints. A novel breakpoint-specific polymerase chain reaction assay was designed to detect the amplification. The assay demonstrated high sensitivity, identifying amplifications in 13 additional, polyclonal infections. Application to 132 further samples identified the common breakpoint in all years tested (2003–2015), with a decline in prevalence after 2012 corresponding to local discontinuation of mefloquine regimens. Assessment of the structure of pvmdr1 amplification in other geographic regions will yield information about the population-specificity of the breakpoints and underlying amplification mechanisms. PMID:27456706

  19. Genomic Analysis Reveals a Common Breakpoint in Amplifications of the Plasmodium vivax Multidrug Resistance 1 Locus in Thailand.

    PubMed

    Auburn, Sarah; Serre, David; Pearson, Richard D; Amato, Roberto; Sriprawat, Kanlaya; To, Sheren; Handayuni, Irene; Suwanarusk, Rossarin; Russell, Bruce; Drury, Eleanor; Stalker, Jim; Miotto, Olivo; Kwiatkowski, Dominic P; Nosten, Francois; Price, Ric N

    2016-10-15

    In regions of coendemicity for Plasmodium falciparum and Plasmodium vivax where mefloquine is used to treat P. falciparum infection, drug pressure mediated by increased copy numbers of the multidrug resistance 1 gene (pvmdr1) may select for mefloquine-resistant P. vivax Surveillance is not undertaken routinely owing in part to methodological challenges in detection of gene amplification. Using genomic data on 88 P. vivax samples from western Thailand, we identified pvmdr1 amplification in 17 isolates, all exhibiting tandem copies of a 37.6-kilobase pair region with identical breakpoints. A novel breakpoint-specific polymerase chain reaction assay was designed to detect the amplification. The assay demonstrated high sensitivity, identifying amplifications in 13 additional, polyclonal infections. Application to 132 further samples identified the common breakpoint in all years tested (2003-2015), with a decline in prevalence after 2012 corresponding to local discontinuation of mefloquine regimens. Assessment of the structure of pvmdr1 amplification in other geographic regions will yield information about the population-specificity of the breakpoints and underlying amplification mechanisms. PMID:27456706

  20. Genomic Analysis Reveals a Common Breakpoint in Amplifications of the Plasmodium vivax Multidrug Resistance 1 Locus in Thailand.

    PubMed

    Auburn, Sarah; Serre, David; Pearson, Richard D; Amato, Roberto; Sriprawat, Kanlaya; To, Sheren; Handayuni, Irene; Suwanarusk, Rossarin; Russell, Bruce; Drury, Eleanor; Stalker, Jim; Miotto, Olivo; Kwiatkowski, Dominic P; Nosten, Francois; Price, Ric N

    2016-10-15

    In regions of coendemicity for Plasmodium falciparum and Plasmodium vivax where mefloquine is used to treat P. falciparum infection, drug pressure mediated by increased copy numbers of the multidrug resistance 1 gene (pvmdr1) may select for mefloquine-resistant P. vivax Surveillance is not undertaken routinely owing in part to methodological challenges in detection of gene amplification. Using genomic data on 88 P. vivax samples from western Thailand, we identified pvmdr1 amplification in 17 isolates, all exhibiting tandem copies of a 37.6-kilobase pair region with identical breakpoints. A novel breakpoint-specific polymerase chain reaction assay was designed to detect the amplification. The assay demonstrated high sensitivity, identifying amplifications in 13 additional, polyclonal infections. Application to 132 further samples identified the common breakpoint in all years tested (2003-2015), with a decline in prevalence after 2012 corresponding to local discontinuation of mefloquine regimens. Assessment of the structure of pvmdr1 amplification in other geographic regions will yield information about the population-specificity of the breakpoints and underlying amplification mechanisms.

  1. 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

  2. Efficient Modification of the CCR5 Locus in Primary Human T Cells With megaTAL Nuclease Establishes HIV-1 Resistance

    PubMed Central

    Romano Ibarra, Guillermo S; Paul, Biswajit; Sather, Blythe D; Younan, Patrick M; Sommer, Karen; Kowalski, John P; Hale, Malika; Stoddard, Barry; Jarjour, Jordan; Astrakhan, Alexander; Kiem, Hans-Peter; Rawlings, David J

    2016-01-01

    A naturally occurring 32-base pair deletion of the HIV-1 co-receptor CCR5 has demonstrated protection against HIV infection of human CD4+ T cells. Recent genetic engineering approaches using engineered nucleases to disrupt the gene and mimic this mutation show promise for HIV therapy. We developed a megaTAL nuclease targeting the third extracellular loop of CCR5 that we delivered to primary human T cells by mRNA transfection. The CCR5 megaTAL nuclease established resistance to HIV in cell lines and disrupted the expression of CCR5 on primary human CD4+ T cells with a high efficiency, achieving up to 80% modification of the locus in primary cells as measured by molecular analysis. Gene-modified cells engrafted at levels equivalent to unmodified cells when transplanted into immunodeficient mice. Furthermore, genetically modified CD4+ cells were preferentially expanded during HIV-1 infection in vivo in an immunodeficient mouse model. Our results demonstrate the feasibility of targeting CCR5 in primary T cells using an engineered megaTAL nuclease, and the potential to use gene-modified cells to reconstitute a patient's immune system and provide protection from HIV infection.

  3. 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.

  4. 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.

  5. Efficient Modification of the CCR5 Locus in Primary Human T Cells With megaTAL Nuclease Establishes HIV-1 Resistance

    PubMed Central

    Romano Ibarra, Guillermo S; Paul, Biswajit; Sather, Blythe D; Younan, Patrick M; Sommer, Karen; Kowalski, John P; Hale, Malika; Stoddard, Barry; Jarjour, Jordan; Astrakhan, Alexander; Kiem, Hans-Peter; Rawlings, David J

    2016-01-01

    A naturally occurring 32-base pair deletion of the HIV-1 co-receptor CCR5 has demonstrated protection against HIV infection of human CD4+ T cells. Recent genetic engineering approaches using engineered nucleases to disrupt the gene and mimic this mutation show promise for HIV therapy. We developed a megaTAL nuclease targeting the third extracellular loop of CCR5 that we delivered to primary human T cells by mRNA transfection. The CCR5 megaTAL nuclease established resistance to HIV in cell lines and disrupted the expression of CCR5 on primary human CD4+ T cells with a high efficiency, achieving up to 80% modification of the locus in primary cells as measured by molecular analysis. Gene-modified cells engrafted at levels equivalent to unmodified cells when transplanted into immunodeficient mice. Furthermore, genetically modified CD4+ cells were preferentially expanded during HIV-1 infection in vivo in an immunodeficient mouse model. Our results demonstrate the feasibility of targeting CCR5 in primary T cells using an engineered megaTAL nuclease, and the potential to use gene-modified cells to reconstitute a patient's immune system and provide protection from HIV infection. PMID:27741222

  6. Isolation of TIR and non-TIR NBS--LRR resistance gene analogues and identification of molecular markers linked to a powdery mildew resistance locus in chestnut rose (Rosa roxburghii Tratt).

    PubMed

    Xu, Qiang; Wen, Xiaopeng; Deng, Xiuxin

    2005-09-01

    Toll and interleukin-1 receptor (TIR) and non-TIR nucleotide binding site-leucine rich repeat (NBS-LRR) resistance gene analogues (RGAs) were obtained from chestnut rose (Rosa roxburghii Tratt) by two PCR-based amplification strategies (direct amplification and overlap extension amplification) with degenerate primers designed to the conserved P-loop, kinase-2, and Gly-Leu-Pro-Leu (GLPL) motifs within the NBS domain of plant resistance gene (R gene) products. Thirty-four of 65 cloned PCR fragments contained a continuous open reading frame (ORF) and their predicted protein products showed homology to the NBS-LRR class R proteins in the GenBank database. These 34 predicted protein sequences exhibited a wide range (19.5--99.4%) of sequence identity among them and were classified into two distinct groups by phylogenetic analysis. The first group consisted of 23 sequences and seemed to belong to the non-TIR NBS-LRR RGAs, since they contained group specific motifs (RNBS-A-non-TIR motif) that are often present in the coiled-coil domain of the non-TIR NBS-LRR class R genes. The second group comprised 11 sequences that contained motifs found in the TIR domain of TIR NBS-LRR class R genes. Restriction fragment length polymorphic (RFLP) markers were developed from some of the RGAs and used for mapping powdery mildew resistance genes in chestnut rose. Three markers, RGA 22 C, RGA 4 A, and RGA 7 B, were identified to be linked to a resistance gene locus, designated CRPM 1 for chestnut rose powdery mildew resistance 1, which accounted for 72% of the variation in powdery mildew resistance phenotype in an F1 segregating population. To our knowledge, this is the first report on isolation, phylogenetic analysis and potential utilization as genetic markers of RGAs in chestnut rose.

  7. 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.

  8. 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.

  9. 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.

  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. 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.

  12. Ultraviolet-B-induced stomatal closure in Arabidopsis is regulated by the UV RESISTANCE LOCUS8 photoreceptor in a nitric oxide-dependent mechanism.

    PubMed

    Tossi, Vanesa; Lamattina, Lorenzo; Jenkins, Gareth I; Cassia, Raúl O

    2014-04-01

    UV RESISTANCE LOCUS8 (UVR8) signaling involves CONSTITUTIVELY PHOTOMORPHOGENIC1, the ELONGATED HYPOCOTYL5 (HY5) transcription factor, and the closely related HY5 HOMOLOG. Some UV-B responses mediated by UVR8 are also regulated by nitric oxide (NO), a bioactive molecule that orchestrates a wide range of processes in plants. In this study, we investigated the participation of the UVR8 pathway and its interaction with NO in UV-B-induced stomatal movements in Arabidopsis (Arabidopsis thaliana). Stomata in abaxial epidermal strips of Arabidopsis ecotype Landsberg erecta closed in response to increasing UV-B fluence rates, with maximal closure after 3-h exposure to 5.46 μmol m⁻² s⁻¹ UV-B. Both hydrogen peroxide (H₂O₂) and NO increased in response to UV-B, and stomatal closure was maintained by NO up to 24 h after the beginning of exposure. Stomata of plants expressing bacterial NO dioxygenase, which prevents NO accumulation, did not close in response to UV-B, although H₂O₂ still increased. When the uvr8-1 null mutant was exposed to UV-B, stomata remained open, irrespective of the fluence rate. Neither NO nor H₂O₂ increased in stomata of the uvr8-1 mutant. However, the NO donor S-nitrosoglutathione induced closure of uvr8-1 stomata to the same extent as in the wild type. Experiments with mutants in UVR8 signaling components implicated CONSTITUTIVELY PHOTOMORPHOGENIC1, HY5, and HY5 HOMOLOG in UV-B-induced stomatal closure. This research provides evidence that the UVR8 pathway regulates stomatal closure by a mechanism involving both H₂O₂ and NO generation in response to UV-B exposure.

  13. 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.

  14. 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

  15. 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

  16. D-alanine modification of a protease-susceptible outer membrane component by the Bordetella pertussis dra locus promotes resistance to antimicrobial peptides and polymorphonuclear leukocyte-mediated killing.

    PubMed

    Taneja, Neetu Kumra; Ganguly, Tridib; Bakaletz, Lauren O; Nelson, Kimberly J; Dubey, Purnima; Poole, Leslie B; Deora, Rajendar

    2013-11-01

    Bordetella pertussis is the causative agent of pertussis, a highly contagious disease of the human respiratory tract. Despite very high vaccine coverage, pertussis has reemerged as a serious threat in the United States and many developing countries. Thus, it is important to pursue research to discover unknown pathogenic mechanisms of B. pertussis. We have investigated a previously uncharacterized locus in B. pertussis, the dra locus, which is homologous to the dlt operons of Gram-positive bacteria. The absence of the dra locus resulted in increased sensitivity to the killing action of antimicrobial peptides (AMPs) and human phagocytes. Compared to the wild-type cells, the mutant cells bound higher levels of cationic proteins and peptides, suggesting that dra contributes to AMP resistance by decreasing the electronegativity of the cell surface. The presence of dra led to the incorporation of d-alanine into an outer membrane component that is susceptible to proteinase K cleavage. We conclude that dra encodes a virulence-associated determinant and contributes to the immune resistance of B. pertussis. With these findings, we have identified a new mechanism of surface modification in B. pertussis which may also be relevant in other Gram-negative pathogens.

  17. The Soybean Rhg1 Locus for Resistance to the Soybean Cyst Nematode Heterodera glycines Regulates the Expression of a Large Number of Stress- and Defense-Related Genes in Degenerating Feeding Cells1[C][W][OA

    PubMed Central

    Kandoth, Pramod Kaitheri; Ithal, Nagabhushana; Recknor, Justin; Maier, Tom; Nettleton, Dan; Baum, Thomas J.; Mitchum, Melissa G.

    2011-01-01

    To gain new insights into the mechanism of soybean (Glycine max) resistance to the soybean cyst nematode (Heterodera glycines), we compared gene expression profiles of developing syncytia in soybean near-isogenic lines differing at Rhg1 (for resistance to Heterodera glycines), a major quantitative trait locus for resistance, by coupling laser capture microdissection with microarray analysis. Gene expression profiling revealed that 1,447 genes were differentially expressed between the two lines. Of these, 241 (16.8%) were stress- and defense-related genes. Several stress-related genes were up-regulated in the resistant line, including those encoding homologs of enzymes that lead to increased levels of reactive oxygen species and proteins associated with the unfolded protein response. These results indicate that syncytia induced in the resistant line are undergoing severe oxidative stress and imbalanced endoplasmic reticulum homeostasis, both of which likely contribute to the resistance reaction. Defense-related genes up-regulated within syncytia of the resistant line included those predominantly involved in apoptotic cell death, the plant hypersensitive response, and salicylic acid-mediated defense signaling; many of these genes were either partially suppressed or not induced to the same level by a virulent soybean cyst nematode population for successful nematode reproduction and development on the resistant line. Our study demonstrates that a network of molecular events take place during Rhg1-mediated resistance, leading to a highly complex defense response against a root pathogen. PMID:21335526

  18. 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

  19. Normal modes of 4-aminobenzonitrile (4-ABN). A comparison of PM3 calculations with experimental jet-cooled spectroscopy

    NASA Astrophysics Data System (ADS)

    Yu, Haiping; Joslin, Evelyn; Zain, Sharifuddin M.; Rzepa, Henry; Phillips, David

    1993-12-01

    The geometry and the normal modes of 4-aminobenzonitrile (4-ABN) in the ground and first excited states have been computed using PM3 formulation. These calculated results, together with previous vapour phase absorption and infrared studies, are used to examine the vibrational modes in the laser-induced fluorescence (LIF) excitation and emission spectra of jet-cooled 4-ABN. The calculated vibrational frequencies of the normal modes show good agreement with experiment both for the electronic ground and the first excited states, but there is a relatively large discrepancy in the position of the electronic origin transition.

  20. 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

  1. 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.

  2. Cell-Autonomous Expression of Barley Mla1 Confers Race-Specific Resistance to the Powdery Mildew Fungus via a Rar1-Independent Signaling Pathway

    PubMed Central

    Zhou, Fasong; Kurth, Joachim; Wei, Fusheng; Elliott, Candace; Valè, Giampiero; Yahiaoui, Nabila; Keller, Beat; Somerville, Shauna; Wise, Roger; Schulze-Lefert, Paul

    2001-01-01

    The barley Mla locus encodes 28 characterized resistance specificities to the biotrophic fungal pathogen barley powdery mildew. We describe a single-cell transient expression assay using entire cosmid DNAs to pinpoint Mla1 within the complex 240-kb Mla locus. The MLA1 cDNA encodes a 108-kD protein containing an N-terminal coiled-coil structure, a central nucleotide binding domain, and a C-terminal leucine-rich repeat region; it also contains a second short open reading frame at the 5′ end that has a possible regulatory function. Although most Mla-encoded resistance specificities require Rar1 for their function, we used the single-cell expression system to demonstrate that Mla1 triggers full resistance in the presence of the severely defective rar1-2 mutant allele. Wheat contains an ortholog of barley Mla, designated TaMla, that is tightly linked to (0.7 centimorgan) but distinct from a tested resistance specificity at the complex Pm3 locus to wheat powdery mildew. Thus, the most polymorphic powdery mildew resistance loci in barley and wheat may have evolved in parallel at two closely linked homeoloci. Barley Mla1 expressed in wheat using the single-cell transformation system failed to trigger a response to any of the wheat powdery mildew Avr genes tested, indicating that AvrMla1 is not genetically fixed in wheat mildew strains. PMID:11226189

  3. 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

  4. 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

  5. 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...

  6. Inherited resistance to N- and B-tropic murine leukemia viruses in vitro: titration patterns in strains SIM and SIM.R congenic at the Fv-1 locus.

    PubMed

    Schuh, V; Blackstein, M E; Axelrad, A A

    1976-05-01

    We have investigated the titration patterns of murine leukemia viruses on mouse embryo cultures derived from a pair of congenic strains differing at the Fv-1 locus. XC plaque and infectious center assays carried out with N- and B-tropic viruses on both SIM (Fv-1nn) and SIM.R(Fv-1bb) host cells yielded results that were best approximated by Poisson one-hit curves. Titration curves of N-tropic virus by direct XC plaque assay were linear and parallel on the different hosts, with titers 1.8 to 2.7 log10 lower on SIM.R and on (SIM X SIM.R)F1 than on SIM cells; similar linear and parallel curves were found for B-tropic virus, with titers 1.4 to 2.0 log10 lower on SIM and (SIM XSIM-R)F1 than on SIM-R cells. In the infectious center assays, the proportion of infected cells was linearly related to multiplicity of infection on both permissive (N- on SIM and B- on SIM.R) restrictive (B- on SIM and N- on SIM.R) genotypes at multiplicities of infection below 0.5; the line relating the variables was about 1 log10 lower in the restrictive than in the permissive situations. At multiplicities of infection where the proportion of infected cells reached a plateau, differences between the results on permissive and restrictive genotypes were considerably reduced. This appeared to be due to the action of non-Fv-1 factors in permissive host. We conclude that the major action of the restrictive allele at the Fv-1 locus in this system is to reduce the probability of successful murine leukemia virus infection without a change in hitness.

  7. The Solanum pimpinellifolium Cf-ECP1 and Cf-ECP4 genes for resistance to Cladosporium fulvum are located at the Milky Way locus on the short arm of chromosome 1.

    PubMed

    Soumpourou, Eleni; Iakovidis, Michael; Chartrain, Laetitia; Lyall, Verity; Thomas, Colwyn M

    2007-11-01

    The interaction between tomato and the leaf mould pathogen Cladosporium fulvum is an excellent model to study gene-for-gene interactions and plant disease resistance gene evolution. Most Cf genes were introgressed into cultivated tomato (Solanum lycopersicum) from wild relatives such as S. pimpinellifolium and novel Cf-ECP genes were recently identified in this species. Our objective is to isolate Cf-ECP1, Cf-ECP2, Cf-ECP4 and Cf-ECP5 to increase our understanding of Cf gene evolution, and the molecular basis for recognition specificity in Cf proteins. The map locations of Cf-ECP2 and Cf-ECP5 have been reported previously and we report here that Cf-ECP1 and Cf-ECP4 map to a different locus on the short arm of chromosome 1. The analysis of selected recombinants and allelism tests showed both genes are located at Milky Way together with Cf-9 and Cf-4. Our results emphasise the importance of this locus in generating novel Cf genes for resistance to C. fulvum. Candidate genes for Cf-ECP1 and Cf-ECP4 were also identified by DNA gel blot analysis of bulked segregant pools. In addition, we generated functional cassettes for expression of the C. fulvum ECP1, ECP2, ECP4 and ECP5 proteins using recombinant Potato Virus X, and three ECPs were also expressed in stable transformed plants. Using marker-assisted selection we have also identified recombinants containing Cf-ECP1, Cf-ECP2, Cf-ECP4 or Cf-ECP5 in cis with a linked T-DNA carrying the non-autonomous Zea mays transposon Dissociation. Using these resources it should now be possible to isolate all four Cf-ECPs using transposon tagging, or a candidate gene strategy.

  8. Image simulation using LOCUS

    SciTech Connect

    Strachan, J.D.; Roberts, J.A.

    1989-09-01

    The LOCUS data base program has been used to simulate images and to solve simple equations. This has been accomplished by making each record (which normally would represent a data entry)represent sequenced or random number pairs.

  9. Development of RAPD and SCAR markers linked to the Pvr4 locus for resistance to PVY in pepper ( Capsicum annuum L.).

    PubMed

    Arnedo-Andrés, S.; Gil-Ortega, R.; Luis-Arteaga, M.; Hormaza, I.

    2002-11-01

    Potato Virus Y (PVY) is the only potyvirus infecting pepper ( Capsicum annuum L.) in Europe. Currently, the development of pepper varieties resistant to PVY seems to be the most-efficient method to control PVY damage. Among the sources of resistance, a monogenic dominant gene Pvr4 confers resistance against all known PVY pathotypes. In this work, bulked segregant analysis (BSA) was used to search for randomly amplified polymorphic DNA (RAPD) markers linked to the Pvr4 gene, using segregating progenies obtained by crossing a homozygous resistant ('Serrano Criollo de Morelos-334') with a homozygous susceptible ('Yolo Wonder') cultivar. Eight hundred decamer primers were screened to identify one RAPD marker (UBC19(1432)) linked in repulsion phase to Pvr4. This marker was converted into a dominant sequence characterised amplified region (SCAR) marker (SCUBC19(1423)). This marker was mapped into a dense Capsicum genetic map in a region where several genes for resistance to different diseases are located. This marker can be useful to identify PVY-resistant genotypes in segregating progenies of pepper in marker-assisted selection (MAS) breeding programs. PMID:12582935

  10. 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

  11. Evolution of new disease specificity at a simple resistance locus in a crop-weed complex: reconstitution of the Lr21 gene in wheat.

    PubMed

    Huang, Li; Brooks, Steven; Li, Wanlong; Fellers, John; Nelson, James C; Gill, Bikram

    2009-06-01

    The wheat leaf-rust resistance gene Lr21 was first identified in an Iranian accession of goatgrass, Aegilops tauschii Coss., the D-genome donor of hexaploid bread wheat, and was introgressed into modern wheat cultivars by breeding. To elucidate the origin of the gene, we analyzed sequences of Lr21 and lr21 alleles from 24 wheat cultivars and 25 accessions of Ae. tauschii collected along the Caspian Sea in Iran and Azerbaijan. Three basic nonfunctional lr21 haplotypes, H1, H2, and H3, were identified. Lr21 was found to be a chimera of H1 and H2, which were found only in wheat. We attempted to reconstitute a functional Lr21 allele by crossing the cultivars Fielder (H1) and Wichita (H2). Rust inoculation of 5876 F(2) progeny revealed a single resistant plant that proved to carry the H1H2 haplotype, a result attributed to intragenic recombination. These findings reflect how plants balance the penalty and the necessity of a resistance gene and suggest that plants can reuse "dead" alleles to generate new disease-resistance specificity, leading to a "death-recycle" model of plant-resistance gene evolution at simple loci. We suggest that selection pressure in crop-weed complexes contributes to this process.

  12. 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...

  13. 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 ...

  14. 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...

  15. Chromosomal Locus for Cadmium Resistance in Pseudomonas putida Consisting of a Cadmium-Transporting ATPase and a MerR Family Response Regulator

    PubMed Central

    Lee, Seon-Woo; Glickmann, Eric; Cooksey, Donald A.

    2001-01-01

    Pseudomonads from environmental sources vary widely in their sensitivity to cadmium, but the basis for this resistance is largely uncharactarized. A chromosomal fragment encoding cadmium resistance was cloned from Pseudomonas putida 06909, a rhizosphere bacterium, and sequence analysis revealed two divergently transcribed genes, cadA and cadR. CadA was similar to cadmium-transporting ATPases known mostly from gram-positive bacteria, and to ZntA, a lead-, zinc-, and cadmium-transporting ATPase from Escherichia coli. CadR was related to the MerR family of response regulators that normally control mercury detoxification in other bacterial systems. A related gene, zntR, regulates zntA in E. coli, but it is not contiguous with zntA in the E. coli genome as cadA and cadR were in P. putida. In addition, unlike ZntA and other CadA homologs, but similar to the predicted product of gene PA3690 in the P. aeruginosa genome, the P. putida CadA sequence had a histidine-rich N-terminal extension. CadR and the product of PA3689 of P. aeruginosa also had histidine-rich C-terminal extensions not found in other MerR family response regulators. Mutational analysis indicated that cadA and cadR are fully responsible for cadmium resistance and partially for zinc resistance. However, unlike zntA, they did not confer significant levels of lead resistance. The cadA promoter was responsive to Cd(II), Pb(II), and Zn(II), while the cadR promoter was only induced by Cd(II). CadR apparently represses its own expression at the transcriptional level. However, CadR apparently does not repress cadA. Homologs of the cadmium-transporting ATPase were detected in many other Pseudomonas species. PMID:11282588

  16. Bond dissociation enthalpies calculated by the PM3 method confirm activity cliffs in radical scavenging of flavonoids.

    PubMed

    Amić, Dragan; Lucić, Bono; Kovacević, Goran; Trinajstić, Nenad

    2009-02-01

    Radical scavenging potency of flavonoids is associated with activity cliffs, i.e., small chemical modifications on flavonoid core can have a significant effect on activity. The presence or absence of the 3',4'-diOH and/or 3-OH group may serve as an activity switch for radical scavenging. The physicochemical background of such an indicator variable, defined previously (Amić et al. (2003) Croat Chem Acta 76:55-61), is confirmed by computation of bond dissociation enthalpies and selecting the minimal of all values relating to flavonoid OH groups. Bond dissociation enthalpies for hydrogen abstraction from OH groups for 29 flavonoids were calculated by the PM3 method. Minimal bond dissociation enthalpy values were obtained for OH groups attached to C-3, C-3' and C-4' positions, and they correspond to the previously introduced indicator variable. Taking into account some driving forces of the radical scavenging mechanism, it is possible to relate structural characteristics of flavonoids to their radical scavenging potency as well as to develop reliable structure-activity models.

  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. Immunological and genetic characterization of 2-deoxygalactose-resistant, galactokinase-deficient mutants of Chinese hamster cells: evidence for structural mutations at the galK locus.

    PubMed Central

    Talbot, B; de Souza, C A; Banville, D; Thirion, J P

    1984-01-01

    Ten independent mutants resistant to 2-deoxygalactose and without any detectable galactokinase activity (null-galactokinase mutations) were isolated from mutagenized Chinese hamster somatic cells. They were analyzed for the presence of serologically cross-reacting material (CRM) with antiserum generated against highly purified Chinese hamster galactokinase. All 10 mutants contain cross-reacting material (i.e., were CRM+), indicating that all the mutations affect the correct expression of a product of the galactokinase structural gene. Complementation analysis among them shows that the 10 mutations fall in one functional genetic unit. PMID:6513922

  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. 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

  2. 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

  3. Characterisation of multidrug-resistant Salmonella Typhimurium 4,[5],12:i:- DT193 strains carrying a novel genomic island adjacent to the thrW tRNA locus.

    PubMed

    Trüpschuch, Sandra; Laverde Gomez, Jenny A; Ediberidze, Ia; Flieger, Antje; Rabsch, Wolfgang

    2010-06-01

    In 2006, monophasic, multidrug-resistant Salmonella enterica spp. enterica serovar 4,[5],12:i:- strains appeared as a novel serotype in Germany, associated with large diffuse outbreaks and increased need for hospitalisation. The emerging 4,[5],12:i:- strains isolated from patients in Germany belong mainly to phage type DT193 according to the Anderson phage typing scheme for S. Typhimurium (STM) and exhibit at least a tetra-drug resistance. The strains have been shown to harbour STM-specific Gifsy-1, Gifsy-2, and ST64B prophages. Furthermore, the extensive sequence similarity of the tRNA regions between one characterised 4,[5],12:i:- phage type DT193 and the S. Typhimurium LT2 strain as well as the STM-specific position of an IS200 element within the fliA-fliB intergenic region (Echeita et al., 2001) prompted us to classify them as a monophasic variant of S. Typhimurium. In 2008, the monophasic variant represented 42.2% of all S. Typhimurium isolates from human analysed at the National Reference Centre. Searching for insertions in tRNA sites resulted in the detection of an 18.4-kb fragment adjacent to the thrW tRNA locus, exhibiting a lower G+C content compared to the LT2 genome. Sequence analysis identified 17 potential ORFs. Some of them showed high similarity to enterobacterial phage sequences and sequences from Shigella boydii, Sh. dysenteriae, avian pathogenic Escherichia coli and other Escherichia spp. The biological function of this novel island with respect to virulence properties and metabolic functions is under investigation.

  4. 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.

  5. A suppressor locus for MODY3-diabetes

    PubMed Central

    Garcia-Gonzalez, Miguel A.; Carette, Claire; Bagattin, Alessia; Chiral, Magali; Makinistoglu, Munevver Parla; Garbay, Serge; Prévost, Géraldine; Madaras, Cécile; Hérault, Yann; Leibovici, Michel; Pontoglio, Marco

    2016-01-01

    Maturity Onset Diabetes of the Young type 3 (MODY3), linked to mutations in the transcription factor HNF1A, is the most prevalent form of monogenic diabetes mellitus. HNF1alpha-deficiency leads to defective insulin secretion via a molecular mechanism that is still not completely understood. Moreover, in MODY3 patients the severity of insulin secretion can be extremely variable even in the same kindred, indicating that modifier genes may control the onset of the disease. With the use of a mouse model for HNF1alpha-deficiency, we show here that specific genetic backgrounds (C3H and CBA) carry a powerful genetic suppressor of diabetes. A genome scan analysis led to the identification of a major suppressor locus on chromosome 3 (Moda1). Moda1 locus contains 11 genes with non-synonymous SNPs that significantly interacts with other loci on chromosomes 4, 11 and 18. Mechanistically, the absence of HNF1alpha in diabetic-prone (sensitive) strains leads to postnatal defective islets growth that is remarkably restored in resistant strains. Our findings are relevant to human genetics since Moda1 is syntenic with a human locus identified by genome wide association studies of fasting glycemia in patients. Most importantly, our results show that a single genetic locus can completely suppress diabetes in Hnf1a-deficiency. PMID:27667715

  6. Genetic mapping of the Tsw locus for resistance to the Tospovirus Tomato spotted wilt virus in Capsicum spp. and its relationship to the Sw-5 gene for resistance to the same pathogen in tomato.

    PubMed

    Jahn, M; Paran, I; Hoffmann, K; Radwanski, E R; Livingstone, K D; Grube, R C; Aftergoot, E; Lapidot, M; Moyer, J

    2000-06-01

    The Tsw gene conferring dominant resistance to the Tospovirus Tomato spotted wilt virus (TSWV) in Capsicum spp. has been tagged with a random amplified polymorphic DNA marker and mapped to the distal portion of chromosome 10. No mapped homologues of Sw-5, a phenotypically similar dominant TSWV resistance gene in tomato, map to this region in C. annuum, although a number of Sw-5 homologues are found at corresponding positions in pepper and tomato. The relationship between Tsw and Sw-5 was also examined through genetic studies of TSWV. The capacity of TSWV-A to overcome the Tsw gene in pepper and the Sw-5 gene in tomato maps to different TSWV genome segments. Therefore, despite phenotypic and genetic similarities of resistance in tomato and pepper, we infer that distinct viral gene products control the outcome of infection in plants carrying Sw-5 and Tsw, and that these loci do not appear to share a recent common evolutionary ancestor.

  7. 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

  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 obesity.

    PubMed

    Neymotin, Florence; Nemzer, Louis R

    2014-01-01

    In the developed world, the hazards associated with obesity have largely outstripped the risk of starvation. Obesity remains a difficult public health issue to address, due in large part to the many disciplines involved. A full understanding requires knowledge in the fields of genetics, endocrinology, psychology, sociology, economics, and public policy - among others. In this short review, which serves as an introduction to the Frontiers in Endocrinology research topic, we address one cross-disciplinary relationship: the interaction between the hunger/satiation neural circuitry, an individual's perceived locus of control, and the risk for obesity. Mammals have evolved a complex system for modulating energy intake. Overlaid on this, in humans, there exists a wide variation in "perceived locus of control" - that is, the extent to which an individual believes to be in charge of the events that affect them. Whether one has primarily an internal or external locus of control itself affects, and is affected by, external and physiological factors and has been correlated with the risk for obesity. Thus, the path from hunger and satiation to an individual's actual behavior may often be moderated by psychological factors, included among which is locus of control. PMID:25339940

  10. 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…

  11. Speaking rate effects on locus equation slope.

    PubMed

    Berry, Jeff; Weismer, Gary

    2013-11-01

    A locus equation describes a 1st order regression fit to a scatter of vowel steady-state frequency values predicting vowel onset frequency values. Locus equation coefficients are often interpreted as indices of coarticulation. Speaking rate variations with a constant consonant-vowel form are thought to induce changes in the degree of coarticulation. In the current work, the hypothesis that locus slope is a transparent index of coarticulation is examined through the analysis of acoustic samples of large-scale, nearly continuous variations in speaking rate. Following the methodological conventions for locus equation derivation, data pooled across ten vowels yield locus equation slopes that are mostly consistent with the hypothesis that locus equations vary systematically with coarticulation. Comparable analyses between different four-vowel pools reveal variations in the locus slope range and changes in locus slope sensitivity to rate change. Analyses across rate but within vowels are substantially less consistent with the locus hypothesis. Taken together, these findings suggest that the practice of vowel pooling exerts a non-negligible influence on locus outcomes. Results are discussed within the context of articulatory accounts of locus equations and the effects of speaking rate change.

  12. 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.

  13. 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…

  14. 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

  15. Locus heterogeneity in autosomal dominant spinocerebellar ataxia: Evidence for the existence of a fifth locus

    SciTech Connect

    Sarrazin, J.; Rouleau, G.A.; Andermann, E.

    1994-09-01

    The autosomal dominantly inherited spinocerebellar ataxias (SCAs) are a heterogeneous group of neurodegenerative disorders. To date, four loci have been identified: the SCA-1 locus (on chromosome (chr) 6p), the SCA-2 locus (on chr 12q), the SCA-3/MJD locus (on chr 14q), and more recently an SCA-4 locus was described (chr 16q) in a Utah kindred. We have studied one large French Canadian kindred with four generations of living affected individuals segregating an autosomal dominant form of SCA. Linkage analysis using anonymous DNA markers which flank the four previously described loci significantly excludes the French Canadian kindred from the SCA-1, SCA-2, SCA-3/MJD and SCA-4 loci. Therefore a fifth, still unmapped, SCA locus remains to be identified.

  16. 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 ...

  17. Suppression among alleles encoding nucleotide-binding-leucine-rich repeat resistance proteins interferes with resistance in F1 hybrid and allele-pyramided wheat plants.

    PubMed

    Stirnweis, Daniel; Milani, Samira D; Brunner, Susanne; Herren, Gerhard; Buchmann, Gabriele; Peditto, David; Jordan, Tina; Keller, Beat

    2014-09-01

    The development of high-yielding varieties with broad-spectrum durable disease resistance is the ultimate goal of crop breeding. In plants, immune receptors of the nucleotide-binding-leucine-rich repeat (NB-LRR) class mediate race-specific resistance against pathogen attack. When employed in agriculture this type of resistance is often rapidly overcome by newly adapted pathogen races. The stacking of different resistance genes or alleles in F1 hybrids or in pyramided lines is a promising strategy for achieving more durable resistance. Here, we identify a molecular mechanism which can negatively interfere with the allele-pyramiding approach. We show that pairwise combinations of different alleles of the powdery mildew resistance gene Pm3 in F1 hybrids and stacked transgenic wheat lines can result in suppression of Pm3-based resistance. This effect is independent of the genetic background and solely dependent on the Pm3 alleles. Suppression occurs at the post-translational level, as levels of RNA and protein in the suppressed alleles are unaffected. Using a transient expression system in Nicotiana benthamiana, the LRR domain was identified as the domain conferring suppression. The results of this study suggest that the expression of closely related NB-LRR resistance genes or alleles in the same genotype can lead to dominant-negative interactions. These findings provide a molecular explanation for the frequently observed ineffectiveness of resistance genes introduced from the secondary gene pool into polyploid crop species and mark an important step in overcoming this limitation.

  18. The role of the hok/sok locus in bacterial response to stressful growth conditions.

    PubMed

    Chukwudi, Chinwe U; Good, Liam

    2015-02-01

    The hok/sok locus is renowned for its plasmid stabilization effect via post-segregational killing of plasmid-free daughter cells. However, the function(s) of the chromosome-encoded loci, which are more abundant in pathogenic strains of a broad range of enteric bacteria, are yet to be understood. Also, the frequent occurrence of this toxin/antitoxin addiction system in multi-drug resistance plasmids suggests additional roles. In this study, the effects of the hok/sok locus on the growth of bacteria in stressful growth-limiting conditions such as high temperature and antibiotic burden were investigated using hok/sok plasmids. The results showed that the hok/sok locus prolonged the lag phase of host cell cultures, thereby enabling the cells to adapt, respond to the stress and eventually thrive in these growth-limiting conditions by increasing the growth rate at exponential phase. The hok/sok locus also enhanced the survival and growth of cells in low cell density cultures irrespective of unfavourable growth conditions, and may complement existing or defective SOS mechanism. In addition to the plasmid stabilization function, these effects would enhance the ability of pathogenic bacteria to establish infections and propagate the antibiotic resistance elements carried on these plasmids, thereby contributing to the virulence of such bacteria.

  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.

  20. Copy Number Variation and Transposable Elements Feature in Recent, Ongoing Adaptation at the Cyp6g1 Locus

    PubMed Central

    Schmidt, Joshua M.; Good, Robert T.; Appleton, Belinda; Sherrard, Jayne; Raymant, Greta C.; Bogwitz, Michael R.; Martin, Jon; Daborn, Phillip J.; Goddard, Mike E.; Batterham, Philip; Robin, Charles

    2010-01-01

    The increased transcription of the Cyp6g1 gene of Drosophila melanogaster, and consequent resistance to insecticides such as DDT, is a widely cited example of adaptation mediated by cis-regulatory change. A fragment of an Accord transposable element inserted upstream of the Cyp6g1 gene is causally associated with resistance and has spread to high frequencies in populations around the world since the 1940s. Here we report the existence of a natural allelic series at this locus of D. melanogaster, involving copy number variation of Cyp6g1, and two additional transposable element insertions (a P and an HMS-Beagle). We provide evidence that this genetic variation underpins phenotypic variation, as the more derived the allele, the greater the level of DDT resistance. Tracking the spatial and temporal patterns of allele frequency changes indicates that the multiple steps of the allelic series are adaptive. Further, a DDT association study shows that the most resistant allele, Cyp6g1-[BP], is greatly enriched in the top 5% of the phenotypic distribution and accounts for ∼16% of the underlying phenotypic variation in resistance to DDT. In contrast, copy number variation for another candidate resistance gene, Cyp12d1, is not associated with resistance. Thus the Cyp6g1 locus is a major contributor to DDT resistance in field populations, and evolution at this locus features multiple adaptive steps occurring in rapid succession. PMID:20585622

  1. Locus of Control in Alcoholics Undergoing Treatment.

    ERIC Educational Resources Information Center

    Haley, Shirley C.

    Alcoholism is a complex behavior pattern. Social learning theory, which is concerned with the analysis of why individuals behave in certain ways and the effects of reinforcement patterns in their behaviors, offers an alternative to traditional treatments of alcoholics. Among alcoholics, drinking is a control issue. Locus of control is viewed as a…

  2. Aspirations, Attributions, and Locus of Control.

    ERIC Educational Resources Information Center

    Samuel, William; McNall, Sidne J.

    Self-evaluation is thought to play a major role in personality and motivation. Preliminary experience with success or failure, levels of aspiration, attributions for performance, and locus of control may all be interrelated factors in human motivation. After receiving success, failure, or no feedback on a concept formation task, subjects (N=90)…

  3. 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…

  4. Cognitive Evaluation Theory, Locus of Control and Positive Verbal Feedback.

    ERIC Educational Resources Information Center

    Lonky, Edward; Reihman, Jacqueline

    This study tests the hypothesis that individual differences in locus of control orientation may mediate elementary school students' responses to positive verbal feedback. A total of 30 kindergarten through fourth grade subjects were assessed for locus of control orientation using the Bialer Children's Locus of Control Questionnaire. To establish a…

  5. Locus equations derived from compensatory articulation.

    PubMed

    Sussman, H M; Fruchter, D; Cable, A

    1995-05-01

    Locus equations are linear regressions of the onset of F2 transitions on their offsets. These functions vowel-normalize the F2 transitions such that they are able to characterize consonantal place categories. The purpose of this research was to determine if compensatory articulation due to bite blocks would alter the normally linear relationship between F2 transition onset and offset frequencies or alter the differential slopes and y intercepts of locus equations as a function of stop place. Six speakers, three male and three female, each produced /bVt/, /dVt/, and /gVt/ tokens for ten vowel contexts under normal and bite block conditions. Extremely linear and practically identical scatterplots were obtained in the two speaking conditions. No adaptation to the bite blocks was found when comparing locus equations derived from the initial versus the final bite block trial. Results are discussed in relation to the "orderly output constraint," which postulates a perceptual function for linearly related F2 transition end points within consonantal place categories.

  6. 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.

  7. A cluster of noncoding RNAs activates the ESR1 locus during breast cancer adaptation

    PubMed Central

    Tomita, Saori; Abdalla, Mohamed Osama Ali; Fujiwara, Saori; Matsumori, Haruka; Maehara, Kazumitsu; Ohkawa, Yasuyuki; Iwase, Hirotaka; Saitoh, Noriko; Nakao, Mitsuyoshi

    2015-01-01

    Estrogen receptor-α (ER)-positive breast cancer cells undergo hormone-independent proliferation after deprivation of oestrogen, leading to endocrine therapy resistance. Up-regulation of the ER gene (ESR1) is critical for this process, but the underlying mechanisms remain unclear. Here we show that the combination of transcriptome and fluorescence in situ hybridization analyses revealed that oestrogen deprivation induced a cluster of noncoding RNAs that defined a large chromatin domain containing the ESR1 locus. We termed these RNAs as Eleanors (ESR1 locus enhancing and activating noncoding RNAs). Eleanors were present in ER-positive breast cancer tissues and localized at the transcriptionally active ESR1 locus to form RNA foci. Depletion of one Eleanor, upstream (u)-Eleanor, impaired cell growth and transcription of intragenic Eleanors and ESR1 mRNA, indicating that Eleanors cis-activate the ESR1 gene. Eleanor-mediated gene activation represents a new type of locus control mechanism and plays an essential role in the adaptation of breast cancer cells. PMID:25923108

  8. 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.

  9. 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.

  10. 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

  11. Regulatory organization of the staphylococcal sae locus.

    PubMed

    Adhikari, Rajan P; Novick, Richard P

    2008-03-01

    This paper describes an investigation of the complex internal regulatory circuitry of the staphylococcal sae locus and the impact of modifying this circuitry on the expression of external genes in the sae regulon. The sae locus contains four genes, the saeR and S two-component signalling module (TCS), and saeP and Q, two upstream genes of hitherto unknown function. It is expressed from two promoters, P(A)sae, which transcribes only the TCS, and P(C)sae, which transcribes the entire locus. A bursa aurealis (bursa) transposon insertion in saeP in a derivative of Staphylococcus aureus NCTC 8325 has a profound effect on sae function. It modifies the activity of the TCS, changing the expression of many genes in the sae regulon, even though transcription of the TCS (from P(A)sae) is not interrupted. Moreover, these effects are not due to disruption of saeP since an in-frame deletion in saeP has essentially no phenotype. The phenotype of S. aureus strain Newman is remarkably similar to that of the saeP : : bursa and this similarity is explained by an amino acid substitution in the Newman saeS gene that is predicted to modify profoundly the signalling function of the protein. This concurrence suggests that the saeP : : bursa insertion affects the signalling function of saeS, a suggestion that is supported by the ability of an saeQR clone, but not an saeR clone, to complement the effects of the saeP : : bursa insertion.

  12. CTCF-mediated reduction of vigilin binding affects the binding of HP1α to the satellite 2 locus.

    PubMed

    Shen, Wen-Yan; Liu, Qiu-Ying; Wei, Ling; Yu, Xiao-Qin; Li, Ran; Yang, Wen-Li; Xie, Xiao-Yan; Liu, Wen-Quan; Huang, Yuan; Qin, Yang

    2014-05-01

    CCCTC-binding factor (CTCF) has been implicated in numerous aspects of chromosome biology, and vigilin, a multi-KH-domain protein, participates in heterochromatin formation and chromosome segregation. We previously showed that CTCF interacts with vigilin. Here, we show that human vigilin, but not CTCF, colocalizes with HP1α on heterochromatic satellite 2 and β-satellite repeats. CTCF up-regulates the transcription of satellite 2, while vigilin down-regulates it. Vigilin depletion or CTCF overexpression reduces the binding of HP1α on the satellite 2 locus. Furthermore, overexpression of CTCF resists the loading of vigilin onto the satellite 2 locus. Thus CTCF may regulate vigilin behavior and thus indirectly influence the binding of HP1α to the satellite 2 locus.

  13. Locus of control and psychological distress among the aged.

    PubMed

    Hale, W D; Hedgepeth, B E; Taylor, E B

    A relationship between locus of control and adjustment has been found in many studies of young adults, with externals generally reporting higher levels of psychological distress. However, studies of locus of control and adjustment in the aged have produced conflicting results. This investigation examined the relationship between locus of control and self-reported psychopathology in a sample of 139 residents of a retirement complex. Correlation coefficients were computed for locus of control and each of the nine symptom dimensions of the Brief Symptom Inventory. These analyses were carried out separately for males and for females to determine if locus of control orientation was associated with adjustment for both males and females. Results indicate that locus of control is correlated with self-reported psychopathology for older women but not for older men. These results and those of related investigations are discussed within the context of Rotter's social learning theory.

  14. Lipooligosaccharide locus class of Campylobacter jejuni: sialylation is not needed for invasive infection.

    PubMed

    Ellström, P; Feodoroff, B; Hänninen, M-L; Rautelin, H

    2014-06-01

    Campylobacter jejuni is a highly diverse enteropathogen that is commonly detected worldwide. It can sometimes cause bacteraemia, but the bacterial characteristics facilitating bloodstream infection are not known. A total of 73 C. jejuni isolates, consecutively collected from blood-borne infections during a 10-year period all over Finland and for which detailed clinical information of the patients were available, were included. We screened the isolates by PCR for the lipooligosaccharide (LOS) locus class and for the presence of the putative virulence genes ceuE, ciaB, fucP, and virB11. The isolates were also tested for γ-glutamyl transpeptidase production. The results were analysed with respect to the clinical characteristics of the patients, and the multilocus sequence types (MLSTs) and serum resistance of the isolates. LOS locus classes A, B, and C, which carry genes for sialylation of LOS, were detected in only 23% of the isolates. These isolates were not more resistant to human serum than those with the genes of non-sialylated LOS locus classes, but were significantly more prevalent among patients with underlying diseases (p 0.02). The fucose permease gene fucP was quite uncommon, but was associated with the isolates with the potential to sialylate LOS (p <0.0001). LOS locus classes and some of the putative virulence factors were associated with MLST clonal complexes. Although some of the bacterial characteristics studied here have been suggested to be important for the invasiveness of C. jejuni, they did not explain why the clinical isolates in the present study were able to cause bacteraemia.

  15. The cell: locus or object of inquiry?

    PubMed

    Bechtel, William

    2010-09-01

    Research in many fields of biology has been extremely successful in decomposing biological mechanisms to discover their parts and operations. It often remains a significant challenge for scientists to recompose these mechanisms to understand how they function as wholes and interact with the environments around them. This is true of the eukaryotic cell. Although initially identified in nineteenth-century cell theory as the fundamental unit of organisms, researchers soon learned how to decompose it into its organelles and chemical constituents and have been highly successful in understanding how these carry out many operations important to life. The emphasis on decomposition is particularly evident in modern cell biology, which for the most part has viewed the cell as merely a locus of the mechanisms responsible for vital phenomena. The cell, however, is also an integrated system and for some explanatory purposes it is essential to recompose it and understand it as an organized whole. I illustrate both the virtues of decomposition (treating the cell as a locus) and recomposition (treating the cell as an object) with recent work on circadian rhythms. Circadian researchers have both identified critical intracellular operations that maintain endogenous oscillations and have also addressed the integration of cells into multicellular systems in which cells constitute units.

  16. Interallelic complementation at the mouse Mitf locus.

    PubMed Central

    Steingrímsson, Eiríkur; Arnheiter, Heinz; Hallsson, Jón Hallsteinn; Lamoreux, M Lynn; Copeland, Neal G; Jenkins, Nancy A

    2003-01-01

    Mutations at the mouse microphthalmia locus (Mitf) affect the development of different cell types, including melanocytes, retinal pigment epithelial cells of the eye, and osteoclasts. The MITF protein is a member of the MYC supergene family of basic-helix-loop-helix-leucine-zipper (bHLHZip) transcription factors and is known to regulate the expression of cell-specific target genes by binding DNA as homodimer or as heterodimer with related proteins. The many mutations isolated at the locus have different effects on the phenotype and can be arranged in an allelic series in which the phenotypes range from near normal to white microphthalmic animals with osteopetrosis. Previous investigations have shown that certain combinations of Mitf alleles complement each other, resulting in a phenotype more normal than that of each homozygote alone. Here we analyze this interallelic complementation in detail and show that it is limited to one particular allele, Mitf(Mi-white) (Mitf(Mi-wh)), a mutation affecting the DNA-binding domain. Both loss- and gain-of-function mutations are complemented, as are other Mitf mutations affecting the DNA-binding domain. Furthermore, this behavior is not restricted to particular cell types: Both eye development and coat color phenotypes are complemented. Our analysis suggests that Mitf(Mi-wh)-associated interallelic complementation is due to the unique biochemical nature of this mutation. PMID:12586714

  17. 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.

  18. 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

  19. 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

  20. Externality and Locus of Control in Obese Children.

    ERIC Educational Resources Information Center

    Isbitsky, Joyce Renee; White, Donna Romano

    1981-01-01

    Significant sex differences indicated that boys generally ate more than girls and held more internal locus of control expectancies. However, obese and normal-weighted children were not differentiated by their performance on either food-related measures nor by their locus of control expectancies. (Author/MP)

  1. 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.

  2. Locus of Control in Underachieving and Achieving Gifted Students.

    ERIC Educational Resources Information Center

    McClelland, Robert; And Others

    1991-01-01

    This study, with 87 underachieving and 77 achieving gifted students in grades 6-9, found that general locus of control measures did not differentiate between the 2 groups, that both scored significantly higher on positive internal than on negative internal locus of control, and that there were no gender or grade effects. (Author/DB)

  3. Locus of Control and Marital Stability: A Longitudinal Study.

    ERIC Educational Resources Information Center

    Constantine, John A.; Bahr, Stephen J.

    1980-01-01

    Investigated relationship between locus of control and marital stability of young men. Factors derived from locus of control measures included leadership, personal, and fate scales. Results indicated the only significant difference was on the leadership scale between men remaining married and those who did not. (RC)

  4. 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…

  5. 40 CFR 798.5200 - Mouse visible specific locus test.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... result, one of which is a statistically significant dose-related increase in the number of specific locus... a statistically significant dose-related increase in the number of specific locus mutations or a... eukaryotes which are the carriers of the genetic information for the species. (c) Reference......

  6. 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

  7. 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

  8. A gene locus for targeted ectopic gene integration in Zymoseptoria tritici☆

    PubMed Central

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

    2015-01-01

    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 sdi1R 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

  9. 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

  10. 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.

  11. 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).

  12. Genomic organization of the S-locus region of Brassica.

    PubMed

    Shiba, Hiroshi; Kenmochi, Masayuki; Sugihara, Minoru; Iwano, Megumi; Kawasaki, Shinji; Suzuki, Go; Watanabe, Masao; Isogai, Akira; Takayama, Seiji

    2003-03-01

    To gain some insights into the structure of the S-locus and the mechanisms that have kept its diversity, a 75-kb genomic fragment containing the self-incompatibility (S) locus region was isolated from the S12-haplotype of Brassica rapa and compared with those of other S-haplotypes. The region around the S determinant genes was highly polymorphic and filled with S-haplotype-specific intergenic sequences. The diverse genomic structure must contribute to the suppression of recombination at the S-locus.

  13. THE LOCUS COERULEUS AND CENTRAL CHEMOSENSITIVITY

    PubMed Central

    Gargaglioni, Luciane H.; Hartzler, Lynn K.; Putnam, Robert W.

    2010-01-01

    The locus coeruleus (LC) lies in the dorsal pons and supplies noradrenergic (NA) input to many regions of the brain, including respiratory control areas. The LC may provide tonic input for basal respiratory drive and is involved in central chemosensitivity since focal acidosis of the region stimulates ventilation and ablation reduces CO2-induced increased ventilation. The output of LC is modulated by both serotonergic and glutamatergic inputs. A large percentage of LC neurons are intrinsically activated by hypercapnia. This percentage and the magnitude of their response are highest in young neonates and decrease dramatically after postnatal day P10. The cellular bases for intrinsic chemosensitivity of LC neurons are comprised of multiple factors, primary among them being reduced extracellular and intracellular pH, which inhibit inwardly rectifying and voltage-gated K+ channels, and activate L-type Ca2+ channels. Activation of KCa channels in LC neurons may limit their ultimate response to hypercapnia. Finally, the LC mediates central chemosensitivity and contains pH-sensitive neurons in amphibians, suggesting that the LC has a long-standing phylogenetic role in respiratory control. PMID:20435170

  14. Sequence Variation Within the Fragile X Locus

    PubMed Central

    Mathews, Debra J.; Kashuk, Carl; Brightwell, Gale; Eichler, Evan E.; Chakravarti, Aravinda

    2001-01-01

    The human genome provides a reference sequence, which is a template for resequencing studies that aim to discover and interpret the record of common ancestry that exists in extant genomes. To understand the nature and pattern of variation and linkage disequilibrium comprising this history, we present a study of ∼31 kb spanning an ∼70 kb region of FMR1, sequenced in a sample of 20 humans (worldwide sample) and four great apes (chimp, bonobo, and gorilla). Twenty-five polymorphic sites and two insertion/deletions, distributed in 11 unique haplotypes, were identified among humans. Africans are the only geographic group that do not share any haplotypes with other groups. Parsimony analysis reveals two main clades and suggests that the four major human geographic groups are distributed throughout the phylogenetic tree and within each major clade. An African sample appears to be most closely related to the common ancestor shared with the three other geographic groups. Nucleotide diversity, π, for this sample is 2.63 ± 6.28 × 10−4. The mutation rate, μ, is 6.48 × 10−10 per base pair per year, giving an ancestral population size of ∼6200 and a time to the most recent common ancestor of ∼320,000 ± 72,000 per base pair per year. Linkage disequilibrium (LD) at the FMR1 locus, evaluated by conventional LD analysis and by the length of segment shared between any two chromosomes, is extensive across the region. PMID:11483579

  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. 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

  17. Multidimensional profiles of health locus of control in Hispanic Americans.

    PubMed

    Champagne, Brian R; Fox, Rina S; Mills, Sarah D; Sadler, Georgia Robins; Malcarne, Vanessa L

    2016-10-01

    Latent profile analysis identified health locus of control profiles among 436 Hispanic Americans who completed the Multidimensional Health Locus of Control scales. Results revealed four profiles: Internally Oriented-Weak, -Moderate, -Strong, and Externally Oriented. The profile groups were compared on sociocultural and demographic characteristics, health beliefs and behaviors, and physical and mental health outcomes. The Internally Oriented-Strong group had less cancer fatalism, religiosity, and equity health attributions, and more alcohol consumption than the other three groups; the Externally Oriented group had stronger equity health attributions and less alcohol consumption. Deriving multidimensional health locus of control profiles through latent profile analysis allows examination of the relationships of health locus of control subtypes to health variables.

  18. A highly polymorphic STR locus in Cannabis sativa.

    PubMed

    Hsieh, Hsing-Mei; Hou, Rur-Jyun; Tsai, Li-Chin; Wei, Chih-Sheng; Liu, Su-Wen; Huang, Li-Hung; Kuo, Yi-Chen; Linacre, Adrian; Lee, James Chun-I

    2003-01-01

    We report on the first short tandem repeat (STR) locus to be isolated from the plant Cannabis sativa. The STR locus, isolated by a hybrid-capture enrichment procedure, was found to contain a simple sequence repeat motif of 6 bp. This 6 bp repeat motif showed no variation in repeat length but with minor variations in repeat unit sequences. The data show the locus to be highly polymorphic with the number of repeat units ranging from 3 to 40 in 108 screened samples. The observed heterozygosity was approximately 87.04%. The forward and reverse primers (CS1F and CS1R) produced no PCR products in cross-reaction study from 20 species of plants, including highly related species such as Humulus japonicus and Nicotiana tabacum. This hexanucleotide repeat DNA locus could be used to identify cannabis samples and predict their genetic relationship as the test is specific to C. sativa and is highly reproducible.

  19. Pleiotropic regulatory locus 2 exhibits unequal genetic redundancy with its homolog PRL1.

    PubMed

    Weihmann, Tabea; Palma, Kristoffer; Nitta, Yukino; Li, Xin

    2012-09-01

    In plants, signaling leading to resistance against biotrophic pathogens is complex. Perception of pathogenic microbes by resistance (R) proteins is relayed though successive activities of downstream components, in a network that is not well understood. PLEIOTROPIC REGULATORY LOCUS 1 (PRL1) and >20 other proteins are members of the MOS4-associated complex (MAC), a regulatory node in defense signaling. Of all characterized MAC members, mutations in PRL1 cause the most severe susceptibility towards both virulent and avirulent microbial pathogens. Genetic suppressors of prl1 represent new signaling elements and may aid in further unraveling of defense mechanisms. Our identification and characterization of a dominant suppressor of prl1 revealed a regulatory, gain-of-function mutation in PLEIOTROPIC REGULATORY LOCUS 2 (PRL2), a close homolog of PRL1. Loss-of-function mutants of PRL2 do not exhibit altered phenotypes; however, prl1 prl2 double mutants exhibit enhanced morphological defects consistent with unequal genetic redundancy between the homologs. Up-regulated gene expression mediated by the dominant prl2-1D allele completely suppresses disease susceptibility in the prl1 mutant background and also restores wild-type appearance, further supporting functional equivalence between the two PRL proteins. PMID:22813545

  20. Genetic characterization and regulation of the nadB locus of Salmonella typhimurium.

    PubMed Central

    Cookson, B T; Olivera, B M; Roth, J R

    1987-01-01

    The nadB locus encodes the first enzyme of NAD synthesis. It has been reported that this gene and nadA are regulated by a positive regulatory protein encoded in the nadB region. In pursuing this regulatory mechanism, we constructed a fine-structure genetic map of the nadB gene. The region appears to include a single complementation group; no evidence for a positive regulatory element was found. Several mutations causing resistance to the analog 6-aminonicotinamide mapped within the structural gene and probably cause resistance to feedback inhibition. Regulatory mutations for nadB were isolated. These mutants mapped far from nadB near the pnuA gene, which encodes a function required for nicotinamide mononucleotide transport. The regulatory mutations appear to affect a distinct function encoded in the same operon as pnuA. PMID:3305482

  1. 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.

  2. 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

  3. [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.

  4. DNA Modification Study of Major Depressive Disorder: Beyond Locus-by-Locus Comparisons

    PubMed Central

    Oh, Gabriel; Wang, Sun-Chong; Pal, Mrinal; Chen, Zheng Fei; Khare, Tarang; Tochigi, Mamoru; Ng, Catherine; Yang, Yeqing A.; Kwan, Andrew; Kaminsky, Zachary A.; Mill, Jonathan; Gunasinghe, Cerisse; Tackett, Jennifer L.; Gottesman, Irving I.; Willemsen, Gonneke; de Geus, Eco J.C.; Vink, Jacqueline M.; Slagboom, P. Eline; Wray, Naomi R.; Heath, Andrew C.; Montgomery, Grant W.; Turecki, Gustavo; Martin, Nicholas G.; Boomsma, Dorret I.; McGuffin, Peter; Kustra, Rafal; Petronis, Art

    2014-01-01

    Background Major depressive disorder (MDD) exhibits numerous clinical and molecular features that are consistent with putative epigenetic misregulation. Despite growing interest in epigenetic studies of psychiatric diseases, the methodologies guiding such studies have not been well defined. Methods We performed DNA modification analysis in white blood cells from monozygotic twins discordant for MDD, in brain prefrontal cortex, and germline (sperm) samples from affected individuals and control subjects (total N = 304) using 8.1K CpG island microarrays and fine mapping. In addition to the traditional locus-by-locus comparisons, we explored the potential of new analytical approaches in epigenomic studies. Results In the microarray experiment, we detected a number of nominally significant DNA modification differences in MDD and validated selected targets using bisulfite pyrosequencing. Some MDD epigenetic changes, however, overlapped across brain, blood, and sperm more often than expected by chance. We also demonstrated that stratification for disease severity and age may increase the statistical power of epimutation detection. Finally, a series of new analytical approaches, such as DNA modification networks and machine-learning algorithms using binary and quantitative depression phenotypes, provided additional insights on the epigenetic contributions to MDD. Conclusions Mapping epigenetic differences in MDD (and other psychiatric diseases) is a complex task. However, combining traditional and innovative analytical strategies may lead to identification of disease-specific etiopathogenic epimutations. PMID:25108803

  5. armA and aminoglycoside resistance in Escherichia coli.

    PubMed

    González-Zorn, Bruno; Teshager, Tirushet; Casas, María; Porrero, María C; Moreno, Miguel A; Courvalin, Patrice; Domínguez, Lucas

    2005-06-01

    We report armA in an Escherichia coli pig isolate from Spain. The resistance gene was borne by self-transferable IncN plasmid pMUR050. Molecular analysis of the plasmid and of the armA locus confirmed the spread of this resistance determinant.

  6. armA and Aminoglycoside Resistance in Escherichia coli

    PubMed Central

    González-Zorn, Bruno; Teshager, Tirushet; Casas, María; Porrero, María C.; Courvalin, Patrice; Domínguez, Lucas

    2005-01-01

    We report armA in an Escherichia coli pig isolate from Spain. The resistance gene was borne by self-transferable IncN plasmid pMUR050. Molecular analysis of the plasmid and of the armA locus confirmed the spread of this resistance determinant. PMID:15963296

  7. 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

  8. 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

  9. Characterization of the bvgR Locus of Bordetella pertussis

    PubMed Central

    Merkel, Tod J.; Barros, Cassia; Stibitz, Scott

    1998-01-01

    Bordetella pertussis, the causative agent of whooping cough, produces a wide array of factors that are associated with its ability to cause disease. The expression and regulation of these virulence factors is dependent upon the bvg locus (originally designated the vir locus), which encodes two proteins: BvgA, a 23-kDa cytoplasmic protein, and BvgS, a 135-kDa transmembrane protein. It is proposed that BvgS responds to environmental signals and interacts with BvgA, a transcriptional regulator which upon modification by BvgS binds to specific promoters and activates transcription. An additional class of genes is repressed by the bvg locus. Expression of this class, the bvg-repressed genes (vrgs [for vir-repressed genes]), is reduced under conditions in which expression of the aforementioned bvg-activated virulence factors is maximal; this repression is dependent upon the presence of an intact bvgAS locus. We have previously identified a locus required for regulation of all of the known bvg-repressed genes in B. pertussis. This locus, designated bvgR, maps to a location immediately downstream of bvgAS. We have undertaken deletion and complementation studies, as well as sequence analysis, in order to identify the bvgR open reading frame and identify the cis-acting sequences required for regulated expression of bvgR. Studies utilizing transcriptional fusions of bvgR to the gene encoding alkaline phosphatase have demonstrated that bvgR is activated at the level of transcription and that this activation is dependent upon an intact bvgAS locus. PMID:9537363

  10. Identification of a locus on mouse chromosome 3 involved in differential susceptibility to Theiler's murine encephalomyelitis virus-induced demyelinating disease.

    PubMed Central

    Melvold, R W; Jokinen, D M; Miller, S D; Dal Canto, M C; Lipton, H L

    1990-01-01

    Theiler's virus-induced demyelinating disease results from a chronic infection in the white matter of the central nervous system and provides an excellent model for human multiple sclerosis. Like multiple sclerosis, there are genetic risk factors in disease development, including genes associated with the major histocompatibility complex and with those encoding the beta chain of the T-cell receptor. Comparisons of the susceptible DBA/2 and resistant C57BL/6 strains have indicated an important role for the H-2D locus and for a non-H-2 gene (not involving the beta chain of the T-cell receptor) in differential susceptibility. In the present report, analysis of recombinant-inbred strains (BXD) between the DBA/2 and C57BL/6 strains indicated that this non-H-2 locus is located at the centromeric end of chromosome 3 near (4 +/- 4 centimorgans) the carbonic anhydrase-2 (Car-2) enzyme locus. PMID:2296080

  11. 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.

  12. 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

  13. 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...

  14. Two-locus sampling distributions and their application.

    PubMed Central

    Hudson, R R

    2001-01-01

    Methods of estimating two-locus sample probabilities under a neutral model are extended in several ways. Estimation of sample probabilities is described when the ancestral or derived status of each allele is specified. In addition, probabilities for two-locus diploid samples are provided. A method for using these two-locus probabilities to test whether an observed level of linkage disequilibrium is unusually large or small is described. In addition, properties of a maximum-likelihood estimator of the recombination parameter based on independent linked pairs of sites are obtained. A composite-likelihood estimator, for more than two linked sites, is also examined and found to work as well, or better, than other available ad hoc estimators. Linkage disequilibrium in the Xq28 and Xq25 region of humans is analyzed in a sample of Europeans (CEPH). The estimated recombination parameter is about five times smaller than one would expect under an equilibrium neutral model. PMID:11779816

  15. Tension versus ecological zones in a two-locus system.

    PubMed

    Hu, Xin-Sheng

    2005-08-01

    Previous theories show that tension and ecological zones are indistinguishable in terms of gene frequency clines. Here I analytically show that these two types of zones can be distinguished in terms of genetic statistics other than gene frequency. A two-locus cline model is examined with the assumptions of random mating, weak selection, no drift, no mutation, and multiplicative viabilities. The genetic statistics for distinguishing the two types of zones are the deviations of one- or two-locus genotypic frequencies from Hardy-Weinberg equilibrium (HWE) or from random association of gametes (RAG), and the deviations of additive and dominance variances from the values at HWE. These deviations have a discontinuous distribution in space and different extents of interruptions in the ecological zone with a sharp boundary, but exhibit a continuous distribution in the tension zone. Linkage disequilibrium enhances the difference between the deviations from HWE and from RAG for any two-locus genotypic frequency.

  16. 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

  17. Molecular organization of the cut locus of Drosophila melanogaster.

    PubMed

    Jack, J W

    1985-10-01

    Mutations of the cut locus (ct) of Drosophila can be divided into four groups based on their phenotypes and complementation patterns. Each group alters the phenotype of a different set of tissues. Two hundred kilobases of ct DNA, located in 7B1-2, have been cloned by chromosomal walking, and the cloned sequences have been used to analyze more than 40 mutants. Based on the location of transposable element mutations and the extent of deficiencies and an inversion, four cut locus regions can be defined. Mutations in each region affect the phenotype of a different set of tissues. The most centromere proximal region contains mutations that are null for cut locus function. Within individual regions, a higher level of organization can be detected. PMID:2996782

  18. 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

  19. Locus-specific view of flax domestication history.

    PubMed

    Fu, Yong-Bi; Diederichsen, Axel; Allaby, Robin G

    2012-01-01

    Crop domestication has been inferred genetically from neutral markers and increasingly from specific domestication-associated loci. However, some crops are utilized for multiple purposes that may or may not be reflected in a single domestication-associated locus. One such example is cultivated flax (Linum usitatissimum L.), the earliest oil and fiber crop, for which domestication history remains poorly understood. Oil composition of cultivated flax and pale flax (L. bienne Mill.) indicates that the sad2 locus is a candidate domestication locus associated with increased unsaturated fatty acid production in cultivated flax. A phylogenetic analysis of the sad2 locus in 43 pale and 70 cultivated flax accessions established a complex domestication history for flax that has not been observed previously. The analysis supports an early, independent domestication of a primitive flax lineage, in which the loss of seed dispersal through capsular indehiscence was not established, but increased oil content was likely occurred. A subsequent flax domestication process occurred that probably involved multiple domestications and includes lineages that contain oil, fiber, and winter varieties. In agreement with previous studies, oil rather than fiber varieties occupy basal phylogenetic positions. The data support multiple paths of flax domestication for oil-associated traits before selection of the other domestication-associated traits of seed dispersal loss and fiber production. The sad2 locus is less revealing about the origin of winter tolerance. In this case, a single domestication-associated locus is informative about the history of domesticated forms with the associated trait while partially informative on forms less associated with the trait.

  20. Complex genetic control of susceptibility to malaria: positional cloning of the Char9 locus

    PubMed Central

    Min-Oo, Gundula; Fortin, Anny; Pitari, Giuseppina; Tam, Mifong; Stevenson, Mary M.; Gros, Philippe

    2007-01-01

    Mouse strains AcB55 and AcB61 are resistant to malaria by virtue of a mutation in erythrocyte pyruvate kinase (PklrI90N). Linkage analysis in [AcB55 × A/J] F2 mice detected a second locus (Char9; logarithm of odds = 4.74) that regulates the blood-stage replication of Plasmodium chabaudi AS independently of Pklr. We characterized the 77 genes of the Char9 locus for tissue-specific expression, strain-specific alterations in gene expression, and polymorphic variants that are possibly associated with differential susceptibility. We identified Vnn1/Vnn3 as the likely candidates responsible for Char9. Vnn3/Vnn1 map within a conserved haplotype block and show expression levels that are strictly cis-regulated by this haplotype. The absence of Vnn messenger RNA expression and lack of pantetheinase protein activity in tissues are associated with susceptibility to malaria and are linked to a complex rearrangement in the Vnn3 promoter region. The A/J strain also carries a unique nonsense mutation that leads to a truncated protein. Vanin genes code for a pantetheinase involved in the production of cysteamine, a key regulator of host responses to inflammatory stimuli. Administration of cystamine in vivo partially corrects susceptibility to malaria in A/J mice, as measured by reduced blood parasitemia and decreased mortality. These studies suggest that pantetheinase is critical for the host response to malaria. PMID:17312006

  1. Lrmp and Bcat1 are candidates for the type I diabetes susceptibility locus Idd6.

    PubMed

    Grimm, Christina H; Rogner, Ute C; Avner, Philip

    2003-06-01

    Three type 1 diabetes associated regions on distal mouse chromosome 6 have recently been defined by the construction and analysis of a series of congenic strains, carrying C3H/HeJ genomic material on a NOD/Lt genetic background. Whilst NOD/Lt alleles at the most distal locus Idd6 confer susceptibility, C3H/HeJ alleles confer resistance to diabetes. Idd6 overlaps with a locus controlling low rates of proliferation in immature NOD-thymocytes, suggesting that Idd6 could be controlling diabetes development through an effect on T cell proliferation rates. Candidates for Idd6 therefore include genes, which are implicated in the immune system and/or in the control of cell proliferation rates, such as Lrmp (Jaw1), Bcat1 and Kras2 that map to the Idd6 candidate region. In the present study, we have undertaken an expression and mutational analysis of all three genes. A surprisingly large number of polymorphisms and amino acid changes were identified in both Lrmp and Bcat1 indicating that they are candidates for Idd6. The two genes are located within a genomic interval of about 3 Mb that contains a large number of single nucleotide polymorphisms (SNP) and which has possibly been derived from distinct ancestral haplotypes in the C3H/HeJ and NOD/Lt strains.

  2. 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

  3. Electrophysiological actions of alfentanil: intracellular studies in the rat locus coeruleus neurones.

    PubMed Central

    Chiu, T. H.; Yeh, M. H.; Tsai, S. K.; Mok, M. S.

    1993-01-01

    1. The electrophysiological effects of alfentanil on 156 neurones of the rat locus coeruleus were investigated by use of intracellular recordings from the in vitro brain slice preparation. 2. Bath application of alfentanil (5-100 nM) reversibly decreased the firing rate of all neurones tested in a dose-dependent manner, with an IC50 4.1.nM. 3. Based on inhibition of the spontaneous firing rate, alfentanil was 22 times more potent than morphine. 4. At 100 nM, alfentanil produced a complete inhibition of firing of all neurones tested (n = 62); the inhibition was accompanied by a membrane hyperpolarization 17.0 +/- 0.8 mV (range 6.1-30.3 mV, n = 62) and a reduction in input resistance 26.4 +/- 1.7% (range 6.5-53%, n = 51). 5. The effects of alfentanil were antagonized by naloxone, with a dissociation equilibrium constant of 2.7 +/- 0.4 nM (n = 6). 6. The reversal potential for the alfentanil-induced hyperpolarization was -110 +/- 2 mV (n = 9), which is approximately the potassium equilibrium potential. 7. The alfentanil-induced hyperpolarization was blocked by caesium chloride and barium chloride. 8. These results indicate that alfentanil binds to mu-opioid receptors on the cell membrane of neurones of the locus coeruleus. This leads to opening of the inward-going rectification potassium channels, resulting in the observed hyperpolarization of the membrane. PMID:8242265

  4. 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

  5. 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

  6. 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

  7. 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

  8. Resistance-resistant antibiotics.

    PubMed

    Oldfield, Eric; Feng, Xinxin

    2014-12-01

    New antibiotics are needed because drug resistance is increasing while the introduction of new antibiotics is decreasing. We discuss here six possible approaches to develop 'resistance-resistant' antibiotics. First, multitarget 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 owing to synergy. Third, discovering multiple-target inhibitors should be possible by using sequential virtual screening. Fourth, repurposing existing drugs can lead to combinations of multitarget 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.

  9. 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.

  10. 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…

  11. 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…

  12. Nucleotide variation at the Gpdh locus in the genus Drosophila.

    PubMed

    Wells, R S

    1996-05-01

    The Gpdh locus was sequenced in a broad range of Drosophila species. In contrast to the extreme evolutionary constraint seen at the amino acid level, the synonymous sites evolve at rates comparable to those of other genes. Gpdh nucleotide sequences were used to infer a phylogenetic tree, and the relationships among the species of the obscura group were examined in detail. A survey of nucleotide polymorphism within D. pseudoobscura revealed no amino acid variation in this species. Applying a modified McDonald-Kreitman test, the amino acid divergence between species in the obscura group does not appear to be excessive, implying that drift is adequate to explain the patterns of amino acid change at this locus. In addition, the level of polymorphism at the Gpdh locus in D. pseudoobscura is comparable to that found at other loci, as determined by a Hudson-Kreitman-Aguadé test. Thus, the pattern of nucleotide variation within and between species at the Gpdh locus is consistent with a neutral model.

  13. 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…

  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. Confirmatory Factor Analysis of the Cancer Locus of Control Scale.

    ERIC Educational Resources Information Center

    Henderson, Jessica W.; Donatelle, Rebecca J.; Acock, Alan C.

    2002-01-01

    Conducted a confirmatory factor analysis of the Cancer Locus of Control scale (M. Watson and others, 1990), administered to 543 women with a history of breast cancer. Results support a three-factor model of the scale and support use of the scale to assess control dimensions. (SLD)

  17. 40 CFR 798.5200 - Mouse visible specific locus test.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... of data for exposed spermatagonial stem cells thereafter. Repeated mating cycles should be conducted... visible characteristics of certain mouse strains. (2) The germ line is the cells in the gonads of higher... mouse germ cells: (A) The visible specific locus test using either 5 or 7 loci. (B) The...

  18. 40 CFR 798.5200 - Mouse visible specific locus test.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... of data for exposed spermatagonial stem cells thereafter. Repeated mating cycles should be conducted... visible characteristics of certain mouse strains. (2) The germ line is the cells in the gonads of higher... mouse germ cells: (A) The visible specific locus test using either 5 or 7 loci. (B) The...

  19. 40 CFR 798.5200 - Mouse visible specific locus test.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... of data for exposed spermatagonial stem cells thereafter. Repeated mating cycles should be conducted... visible characteristics of certain mouse strains. (2) The germ line is the cells in the gonads of higher... mouse germ cells: (A) The visible specific locus test using either 5 or 7 loci. (B) The...

  20. 40 CFR 798.5200 - Mouse visible specific locus test.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... of data for exposed spermatagonial stem cells thereafter. Repeated mating cycles should be conducted... visible characteristics of certain mouse strains. (2) The germ line is the cells in the gonads of higher... mouse germ cells: (A) The visible specific locus test using either 5 or 7 loci. (B) The...

  1. 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…

  2. 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…

  3. Confirmatory Factor Analysis of the Work Locus of Control Scale

    ERIC Educational Resources Information Center

    Oliver, Joseph E.; Jose, Paul E.; Brough, Paula

    2006-01-01

    Original formulations of the Work Locus of Control Scale (WLCS) proposed a unidimensional structure of this measure; however, more recently, evidence for a two-dimensional structure has been reported, with separate subscales for internal and external loci of control. The current study evaluates the one- and two-factor models with confirmatory…

  4. Thought Recognition, Locus of Control, and Adolescent Well-Being.

    ERIC Educational Resources Information Center

    Kelley, Thomas M.; Stack, Steven A.

    2000-01-01

    Reviews the underlying assumptions and principles of a new psychological paradigm, Psychology of Mind/Health Realization (POM/HR). Thought recognition is compared with locus of control (LOC). The relationship of LOC to self-reported happiness and satisfaction is examined from the perspective of POM/HR, using a sample of at-risk adolescents…

  5. The Influence of Labor Market Discrimination on Locus of Control.

    ERIC Educational Resources Information Center

    Becker, Brian E.; Krzystofiak, Frank J.

    1982-01-01

    Drawing on a national probability sample (N=2,857) of young men, used multiple regression analysis to estimate the effect of labor market discrimination on subsequent locus of control. Results indicated that perceptions of employment discrimination influenced the level of externality among Blacks, over and above racial identification. (Author/RC)

  6. 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…

  7. Molecular Epidemiology of sil Locus in Clinical Streptococcus pyogenes Strains

    PubMed Central

    Plainvert, Céline; Dinis, Márcia; Ravins, Miriam; Hanski, Emanuel; Touak, Gérald; Dmytruk, Nicolas; Fouet, Agnès

    2014-01-01

    Streptococcus pyogenes (group A Streptococcus [GAS]) causes a wide variety of diseases, ranging from mild noninvasive to severe invasive infections. Mutations in regulatory components have been implicated in the switch from colonization to invasive phenotypes. The inactivation of the sil locus, composed of six genes encoding a quorum-sensing complex, gives rise to a highly invasive strain. However, studies conducted on limited collections of GAS strains suggested that sil prevalence is around 15%; furthermore, whereas a correlation between the presence of sil and the genetic background was suggested, no link between the presence of a functional sil locus and the invasive status was assessed. We established a collection of 637 nonredundant strains covering all emm genotypes present in France and of known clinical history; 68%, 22%, and 10% were from invasive infections, noninvasive infections, and asymptomatic carriage, respectively. Among the 637 strains, 206 were sil positive. The prevalence of the sil locus varied according to the emm genotype, being present in >85% of the emm4, emm18, emm32, emm60, emm87, and emm90 strains and absent from all emm1, emm28, and emm89 strains. A random selection based on 2009 French epidemiological data indicated that 16% of GAS strains are sil positive. Moreover, due to mutations leading to truncated proteins, only 9% of GAS strains harbor a predicted functional sil system. No correlation was observed between the presence or absence of a functional sil locus and the strain invasiveness status. PMID:24671796

  8. Locus of Control and Learning Disabilities: A Review and Discussion.

    ERIC Educational Resources Information Center

    Dudley-Marling, Curtis C.; And Others

    1982-01-01

    A literature review reveals that learning disabled children are more likely than normal achievers to attribute successes, but not failures, to external factors. The implications of locus of control for the field of learning disabilities are discussed in terms of its relation to academic achievement, learned helplessness, and remediation programs.…

  9. 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

  10. Fixing the broken system of genetic locus symbols

    PubMed Central

    Lohmann, Katja; Lang, Anthony; Klein, Christine

    2012-01-01

    Originally, locus symbols (e.g., DYT1) were introduced to specify chromosomal regions that had been linked to a familial disorder with a yet unknown gene. Symbols were systematically assigned in a numerical series to designate mapped loci for a specific phenotype or group of phenotypes. Since the system of designating and using locus symbols was originally established, both our knowledge and our techniques of gene discovery have evolved substantially. The current system has problems that are sources of confusion, perpetuate misinformation, and misrepresent the system as a useful reference tool for a list of inherited disorders of a particular phenotypic class. These include erroneously assigned loci, duplicated loci, missing symbols, missing loci, unconfirmed loci in a consecutively numbered system, combining causative genes and risk factor genes in the same list, and discordance between phenotype and list assignment. In this article, we describe these problems and their impact, and propose solutions. The system could be significantly improved by creating distinct lists for clinical and research purposes, creating more informative locus symbols, distinguishing disease-causing mutations from risk factors, raising the threshold of evidence prior to assigning a locus symbol, paying strict attention to the predominant phenotype when assigning symbols lists, and having a formal system for reviewing and continually revising the list that includes input from both clinical and genetics experts. PMID:22454269

  11. 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.…

  12. Motive to Avoid Success, Locus of Control, and Reinforcement Avoidance.

    ERIC Educational Resources Information Center

    Katovsky, Walter

    Subjects were four groups of 12 college women, high or low in motive to avoid success (MAS) and locus of control (LC), were reinforced for response A on a fixed partial reinforcement schedule on three concept learning tasks, one task consisting of combined reward and punishment, another of reward only, and one of punishment only. Response B was…

  13. 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…

  14. 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…

  15. 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

  16. [Drug compliance and health locus of control in schizophrenia].

    PubMed

    Combes, C; Feral, F

    2011-05-01

    Schizophrenia is a frequent disorder since it affects about 1% of the general population. Drug compliance, that is to say patients' adherence to their treatment, remains rather poor concerning this disease with, on an average, one patient out of two not complying with his/her medication. Among the factors influencing drug compliance, we focused on patients' beliefs in terms of health control, a concept known as health locus of control. This is a concept that originated from social psychology and derived from the Rotters' original concept of locus of control: it corresponds to the type of connexion established by an individual between subsequent events in the history of his/her disease and internal (personal abilities) or external factors (chance, powerful others). Nowadays, the tridimensional structure of this concept is commonly admitted as being in three dimensions: internality, chance externality and powerful others externality, the latter group being divided between doctors and others. We have assumed that there is a correlation between the degree of drug compliance and the internal and/or doctors' external health locus of control. For this purpose, we have determined the quality of drug compliance by using the Medical Adherence Rating Scale (MARS) and the type of health locus of control by using the Multidimensional Health Locus of Control (MHLC) scale among 65 schizophrenic patients. We have also considered it was important to evaluate patients' insight by using the Amador's scale (Scale of Unawareness of Mental Disorder) because many researchers have established a strong correlation between insight and drug compliance in schizophrenia. Associations between the four dimensions of health locus of control ("internal", "chance external", "others external" and "doctors' external") and drug compliance were assessed by estimating Spearman's rank correlation coefficient (r) and its degree of significance (p). These associations were judged significant at an alpha

  17. 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.

  18. 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

  19. Homozygosity mapping of the Werner syndrome locus (WRN)

    SciTech Connect

    Nakura, J.; Miki, T.; Kamino, K.

    1994-10-01

    Werner syndrome (WS) is an autosomal recessive disorder characterized by the early onset of several age-related diseases. The locus for this disease was recently mapped to 8p12. We studied 27 WS kindreds of mixed ethnic origins, 26 of which were consanguineous. In 24 of these families, the affected subject was given the diagnosis of {open_quotes}definite{close_quotes} WS and affected subjects in the remaining 3 pedigrees were given the diagnosis of {open_quotes}probable{close_quotes} WS. Affected subjects from each kindred were genotyped for 13 short tandem repeat polymorphic sites. Two-point linkage analysis yielded significant evidence for linkage to D8S137, D8S339, D8S87, PLAT, D8S165, and D8S166. The locus yielding a maximum lod score at the smallest recombination fraction was D8S339, suggesting that this marker is the closest to the WS gene (WRN locus) of those tested. D8S339 gave significant lod scores (Z{sub max}{>=}3.0) for both Japanese and non-Japanese (mostly Caucasian) families, demonstrating that a single locus is responsible for WS in both groups. Multipoint analysis of these markers yielded a maximum lod score of 17.05 at a distance of approximately 0.6 cM from D8S339. The combined evidence from 2-point analysis, multipoint analysis, and analysis of regions of homozygosity in subjects from inbred pedigrees indicates that the WRN locus is between D8S131 and D8S87, in an 8.3-cM interval containing D8S339. 32 refs., 1 fig., 5 tabs.

  20. 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

  1. 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…

  2. 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…

  3. Adolescent Values Clarification: A Positive Influence on Perceived Locus of Control.

    ERIC Educational Resources Information Center

    James, Mark R.

    1990-01-01

    Used locus of control assessments to monitor specific aspect of adolescent chemical dependency treatment program. Used song lyric analysis activities to note short-term modifications in experimental group's (N=10) perceived locus of control. No improvements were noted in matched control group's locus of control. Findings suggest that addictions…

  4. 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…

  5. 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…

  6. Identification of two loci for resistance to clubroot (Plasmodiophora brassicae Woronin) in Brassica rapa L.

    PubMed

    Suwabe, K; Tsukazaki, H; Iketani, H; Hatakeyama, K; Fujimura, M; Nunome, T; Fukuoka, H; Matsumoto, S; Hirai, M

    2003-10-01

    In an analysis of 114 F(2) individuals from a cross between clubroot-resistant and susceptible lines of Brassica rapa L., 'G004' and 'Hakusai Chukanbohon Nou 7' (A9709), respectively, we identified two loci, Crr1 and Crr2, for clubroot (caused by Plasmodiophora brassicae Woronin) resistance. Each locus segregated independently among the F(2) population, indicating that the loci reside on a different region of chromosomes or on different chromosomes. Genetic analysis showed that each locus had little effect on clubroot resistance by itself, indicating that these two loci are complementary for clubroot resistance. The resistance to clubroot was much stronger when both loci were homozygous for resistant alleles than when they were heterozygous. These results indicate that clubroot resistance in B. rapa is under oligogenic control and at least two loci are necessary for resistance.

  7. Externality and locus of control in obese children.

    PubMed

    Isbitsky, J R; White, D R

    1981-03-01

    Fifty-nine obese and normal-weight children, aged 8-12 years were compared on two dimensions of "externality," previously examined in obese adults. Significant sex difference indicated that boys generally ate more than girls and held more internal locus of control expectancies. However, obese and normal-weight children were not differentiated by their performance on either a food-related or three nonfood-related measures of external-cue responsiveness, nor by their locus of control expectancies. Furthermore, the various measures were neither strongly nor consistently intercorrelated, providing little support for the notion of a single underlying dimension of "externality." The contribution of physiological, sensory, cognitive-motivational, and sociocultural parameters to the regulation of eating behavior was discussed.

  8. Negative Complementation at the Notch Locus of DROSOPHILA MELANOGASTER

    PubMed Central

    Foster, Geoffrey G.

    1975-01-01

    Four Abruptex alleles (AxE1, AxE2, Ax9B2, and Ax16172) have been mapped within the Notch locus. Based on their visible phenotypes and their interactions with one another and with N mutations, the Ax alleles can be divided into two groups. Heterozygous combinations of members of the same group are intermediate in phenotype compared to the respective homozygotes, whereas heterozygotes of Ax alleles from different groups exhibit negative heterosis, being much less viable and more extremely mutant than either homozygote. It is suggested that the Notch locus is a multi-functional regulator ("integrator") gene, whose product possesses both "repressor" and "activator" functions for the processes it regulates. PMID:812768

  9. Locus of control: a work-related variable?

    PubMed

    Knoop, R

    1989-02-01

    Inconsistencies in findings between age and perceived locus of control of reinforcement were examined in light of social learning theory. Absence of work was hypothesized to reduce opportunities for reinforcement and thus expectancies. No differences were found in internal-external (I-E) locus of control among nine age groups (20 to 65 years) for subjects (882 school teachers) during the span of their work lives. It seems that I-E depends on the frequency and intensity of expectancies for behavior reinforcement sequences that work affords. Before and after work life there is not only less to control, but many of the nonwork reinforcers are not contingent on one's own behavior. Relinquishing internal control and a shift of focus toward reflection on experience and meaning of ife may well be a desirable and natural process for older people.

  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. Locus-specific gene repositioning in prostate cancer

    PubMed Central

    Leshner, Marc; Devine, Michelle; Roloff, Gregory W.; True, Lawrence D.; Misteli, Tom; Meaburn, Karen J.

    2016-01-01

    Genes occupy preferred spatial positions within interphase cell nuclei. However, positioning patterns are not an innate feature of a locus, and genes can alter their localization in response to physiological and pathological changes. Here we screen the radial positioning patterns of 40 genes in normal, hyperplasic, and malignant human prostate tissues. We find that the overall spatial organization of the genome in prostate tissue is largely conserved among individuals. We identify three genes whose nuclear positions are robustly altered in neoplastic prostate tissues. FLI1 and MMP9 position differently in prostate cancer than in normal tissue and prostate hyperplasia, whereas MMP2 is repositioned in both prostate cancer and hyperplasia. Our data point to locus-specific reorganization of the genome during prostate disease. PMID:26564800

  12. 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

  13. Health locus of control and participation in physical activity.

    PubMed

    Carlson, B R; Petti, K

    1989-01-01

    Abstract The purpose of this study was to determine the physical activity participation patterns of college students when defined by their Health Locus of Control orientation. One thousand thirty-three college-aged students completed the Wellness Activity Profile, a questionnaire that yielded data on Health Locus of Control and self-reported frequency of participation in physical activities. Discriminant analyses indicated that the combination of physical activities associated with internally and externally oriented students were different for both males and females. Participation in high caloric expenditure activities was more frequent among internal subjects (Male: bicycling, volleyball, other individual sports, and snorkel/scuba diving; Female: basketball, weight training, tennis, fast walking/jogging/running, and judo/karate), while low caloric expenditure activities were associated with an external orientation (Male: baseball/softball, sailing, fishing, golf, and other recreational sports; Female: track and field jumping and fishing).

  14. Two-locus inbreeding measures for recurrent selection.

    PubMed

    Choy, S C; Weir, B S

    1977-03-01

    For a population undergoing recurrent selection, a method is presented for determining the average inbreeding coefficients at the end of each breeding cycle. The coefficients are derived in terms of probability measures that genes are identical by descent. For the one-locus case, two digametic measures are defined and employed in the derivation of a recurrence formula for the inbreeding coefficient. Two further classes of measures, trigametic and quadrigametic, are required for transition from one cycle to the previous one to allow the calculation of the inbreeding function for the two-locus case. Numerical values of the average probability of double identity by descent for populations with various imposed assumptions are listed to illustrate the effects of linkage and population size on the accrual of inbreeding and hence of homozygosity.

  15. Identification of a functional capsule locus in Streptococcus mitis.

    PubMed

    Rukke, H V; Hegna, I K; Petersen, F C

    2012-04-01

    The polysaccharide capsule of Streptococcus pneumoniae is a hallmark for virulence in humans. In its close relative Streptococcus mitis, a common human commensal, analysis of the sequenced genomes of six strains revealed the presence of a putative capsule locus in four of them. We constructed an isogenic S. mitis mutant from the type strain that lacked the 19 open reading frames in the capsule locus (Δcps mutant), using a deletion strategy similar to previous capsule functional studies in S. pneumoniae. Transmission electron microscopy and atomic force microscopy revealed a capsule-like structure in the S. mitis type strain that was absent or reduced in the Δcps mutant. Since S. mitis are predominant oral colonizers of tooth surfaces, we addressed the relevance of the capsule locus for the S. mitis overall surface properties, autoaggregation and biofilm formation. The capsule deletion resulted in a mutant with approximately two-fold increase in hydrophobicity. Binding to the Stains-all cationic dye was reduced by 40%, suggesting a reduction in the overall negative surface charge of the mutant. The mutant exhibited also increased autoaggregation in coaggregation buffer, and up to six-fold increase in biofilm levels. The results suggested that the capsule locus is associated with production of a capsule-like structure in S. mitis and indicated that the S. mitis capsule-like structure may confer surface attributes similar to those associated with the capsule in S. pneumoniae.

  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. 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

  18. 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

  19. Population genetics of the HRAS1 minisatellite locus

    SciTech Connect

    Devlin, B.; Risch, N. ); Krontiris, T. New England Medical Center Hospital, Boston, MA )

    1993-12-01

    Several years ago it was reported that rare HRAS1 VNTR alleles occurred more frequently in US Caucasian cancer patients than in unaffected controls. Such an association, in theory, could be caused by undetected population heterogeneity. Also, in a study clearly relevant to this issue, it was recently reported that significant deviations from Hardy-Weinberg equilibrium exist at this locus in a sample of US Caucasians. These considerations motivate population genetic analysis of the HRAS1 locus. From published studies of the HRAS1 VNTR locus, which classified alleles into types, the authors found only small differences in the allele frequency distributions of samples from various European nations, although there were larger differences among ethnic groups (African American, Caucasian, and Oriental). In an analysis of variation of rare-allele frequencies among samples from four European nations, most of the variance was attributable to molecular methodology, and very little of the variance was accounted for by nationality. In addition, the authors showed that mixture of European subpopulations should result in only minor deviations from expected genotype proportions in a Caucasian database and demonstrated that there was no significant deviation from Hardy-Weinberg equilibrium in the HRAS1 data. 35 refs., 4 tabs.

  20. Targeted disruption of the porcine immunoglobulin kappa light chain locus.

    PubMed

    Ramsoondar, J; Mendicino, M; Phelps, C; Vaught, T; Ball, S; Monahan, J; Chen, S; Dandro, A; Boone, J; Jobst, P; Vance, A; Wertz, N; Polejaeva, I; Butler, J; Dai, Y; Ayares, D; Wells, K

    2011-06-01

    Inactivation of the endogenous pig immunoglobulin (Ig) loci, and replacement with their human counterparts, would produce animals that could alleviate both the supply and specificity issues of therapeutic human polyclonal antibodies (PAbs). Platform genetics are being developed in pigs that have all endogenous Ig loci inactivated and replaced by human counterparts, in order to address this unmet clinical need. This report describes the deletion of the porcine kappa (κ) light chain constant (Cκ) region in pig primary fetal fibroblasts (PPFFs) using gene targeting technology, and the generation of live animals from these cells via somatic cell nuclear transfer (SCNT) cloning. There are only two other targeted loci previously published in swine, and this is the first report of a targeted disruption of an Ig light chain locus in a livestock species. Pigs with one targeted Cκ allele (heterozygous knockout or ±) were bred together to generate Cκ homozygous knockout (-/-) animals. Peripheral blood mononuclear cells (PBMCs) and mesenteric lymph nodes (MLNs) from Cκ -/- pigs were devoid of κ-containing Igs. Furthermore, there was an increase in lambda (λ) light chain expression when compared to that of wild-type littermates (Cκ +/+). Targeted inactivation of the Ig heavy chain locus has also been achieved and work is underway to inactivate the pig lambda light chain locus.

  1. Purpose in life, depression, and locus of control.

    PubMed

    Phillips, W M

    1980-07-01

    Parallel to Frankl's theory of the search for meaning, which posits the separateness but intertwining of the psychological and existential realms, the Purpose In Life Test (PIL) has been found to have a low to moderate relationship with most conceptually related psychological measures. Extending separate correlational studies of the PIL with depression and locus of control, the current study inspected the relationship of individual PIL items to groups formed according to Zung Self-Rating Depression Scale and Rotter Internal-External Locus Of Control scores. One-hundred thirty-four Ss were split into four groups: Depressed external, depressed internals, nondepressed externals, and nondepressed internals. Although ungrouped correlational analysis of PIL items revealed only seven significant relationships with depression and two with locus of control, multiple discriminate analysis was successful in correctly classifying depressed externals about three-fourths of the time, and the overall "hit rate" for the four groups was above 60%. In addition to further validating the interaction of purpose in life with related psychological and social expectancy variables, results indicated a compounding effect between depression and external perception of reinforcement control with PIL scores in general, and two items (#4, 12) in particular, which appear to reflect the experience of current congruent involvement between the individual and his world.

  2. 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

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

    SciTech Connect

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

    1992-11-01

    The X-linked hypohidrotic ectodermal dysplasia (EDA) locus has been previously localized to the subchromosomal region Xq11-q21.1. The authors have extended 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 analysis 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 heterozygosites 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 consegregates with the mouse tabby (Ta) locus, a potential homologue to the EDA locus. The absence of recombination between EDA and the DXSA732 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. 36 refs., 1 fig., 5 tabs.

  7. Cia27 is a novel non-MHC arthritis severity locus on rat chromosome 10 syntenic to the rheumatoid arthritis 17q22-q25 locus.

    PubMed

    Brenner, M; Laragione, T; Yarlett, N C; Li, W; Mello, A; Gulko, P S

    2006-07-01

    Cia27 on rat chromosome 10 is a collagen-induced arthritis (CIA) severity quantitative trait locus originally identified in a study of (DA x ACI) F2. As an initial step towards the positional cloning of the Cia27 gene, a 17 cM (21 Mb) interval from the DA strain (arthritis-susceptible) containing the two-logarithm of odds support interval comprising Cia27 was introgressed into the ACI (arthritis-resistant) background through genotype-guided congenic breeding. ACI.DA(Cia27) congenics developed a significantly more severe form of arthritis (CIA), with a 5.9-fold increase in median arthritis severity index, a parameter known to correlate with synovial inflammation, and cartilage and bone erosions, compared with ACI (P< or =0.001). The arthritis severity enhancing effect could be detected from day 21 onwards. Rats heterozygous at the congenic interval developed a disease similar to ACI rats, suggesting that DA alleles operate in a recessive manner. Levels of autoantibodies anti-rat type II collagen did not correlate with arthritis severity. Synovial tissue mRNA levels of interleukin-1beta (IL-1beta) were significantly increased in ACI.DA(Cia27) congenics compared with ACI. These results demonstrate that Cia27 harbors a novel arthritis severity regulatory gene. The identification of this gene should facilitate the identification of the rheumatoid arthritis gene mapped to the human syntenic region on chromosome 17q22-q25. PMID:16691185

  8. 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

  9. 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

  10. A Nomadic Subtelomeric Disease Resistance Gene Cluster in Common Bean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The B4 resistance (R)-gene cluster, located in subtelomeric region of chromosome 4, is one of the largest clusters known in common bean (Phaseolus vulgaris, Pv). We sequenced 650 kb spanning this locus and annotated 97 genes, 26 of which correspond to Coiled-coil-Nucleotide-Binding-Site-Leucine-Rich...

  11. 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

  12. 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

  13. The genetics of resistance to powdery mildew in cultivated oats (Avena sativa L.): current status of major genes.

    PubMed

    Hsam, Sai L K; Mohler, Volker; Zeller, Friedrich J

    2014-05-01

    The genetics of resistance to powdery mildew caused by Blumeria graminis f. sp. avenae of four cultivated oats was studied using monosomic analysis. Cultivar 'Bruno' carries a gene (Pm6) that shows a recessive mode of inheritance and is located on chromosome 10D. Cultivar 'Jumbo' possesses a dominant resistance gene (Pm1) on chromosome 1C. In cultivar 'Rollo', in addition to the gene Pm3 on chromosome 17A, a second dominant resistance gene (Pm8) was identified and assigned to chromosome 4C. In breeding line APR 122, resistance was conditioned by a dominant resistance gene (Pm7) that was allocated to chromosome 13A. Genetic maps established for resistance genes Pm1, Pm6 and Pm7 employing amplified fragment length polymorphism (AFLP) markers indicated that these genes are independent of each other, supporting the results from monosomic analysis.

  14. 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...

  15. The pvr1 locus in Capsicum encodes a translation initiation factor eIF4E that interacts with Tobacco etch virus VPg.

    PubMed

    Kang, Byoung-Cheorl; Yeam, Inhwa; Frantz, James D; Murphy, John F; Jahn, Molly M

    2005-05-01

    Mutations in the eIF4E homolog encoded at the pvr1 locus in Capsicum result in broad-spectrum potyvirus resistance attributed to the pvr1 resistance allele, a gene widely deployed in agriculture for more than 50 years. We show that two other resistance genes, previously known to be eIF4E with narrower resistance spectra, pvr2(1) and pvr2(2), are alleles at the pvr1 locus. Based on these data and current nomenclature guidelines, we have re-designated these alleles, pvr1(1) and pvr1(2), respectively. Point mutations in pvr1, pvr1(1), and pvr1(2) grouped to similar regions of eIF4E and were predicted by protein homology models to cause conformational shifts in the encoded proteins. The avirulence determinant in this potyvirus system has previously been identified as VPg, therefore yeast two-hybrid and GST pull-down assays were carried out with proteins encoded by the pvr1 alleles and VPg from two different strains of Tobacco etch virus (TEV) that differentially infected Capsicum lines carrying these genes. While the protein encoded by the susceptible allele pvr1+ interacted strongly, proteins translated from all three resistance alleles (pvr1, pvr1(1), and pvr1(2)) failed to bind VPg from either strain of TEV. This failure to bind correlated with resistance or reduced susceptibility, suggesting that interruption of the interaction between VPg and this eIF4E paralog may be necessary, but is not sufficient for potyvirus resistance in vivo. Among the three resistance alleles, only the pvr1 gene product failed to bind m7-GTP cap-analog columns, suggesting that disrupted cap binding is not required for potyvirus resistance.

  16. 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

  17. 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 ...

  18. 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, ...

  19. 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

  20. 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

  1. 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

  2. Intragenic recombination at the human phosphoglucomutase 1 locus: Predictions fulfilled

    SciTech Connect

    Takahashi, Norio ); Neel, J.V. )

    1993-11-15

    In 1982, the authors advanced a phylogeny that attributed eight alleles of the phosphoglucomutase 1 locus (PGM1) to three independent mutations in a primal allele, followed by four intragenic recombination events involving these mutants. The recent description of a cDNA probe for this locus now renders it possible to test the validity of this phylogeny. cDNAs of PGM1 reverse-transcribed from mRNAs obtained from Japanese individuals possessing eight different electrophoretically defined alleles (PGM1*1+, PGM1*1-, PGM1*2+, PGM1*2-, PGM1*3+, PGM1*3-, PGM1*7+, PGM1*7-) were amplified by PCR and the sequences were determined. Only three different base substitutions were identified when PGM1*1+ was taken as the reference allele, as follows: an A to T transversion at residue 265, a C to T transition at residue 723, and a T to C transition at residue 1320. The second of these substitutions creates a BglII restriction enzyme site and the third creates a Nla III site. At the amino acid level, these substitutions alter amino acid 67 from Lys to Met, amino acid 220 from Arg to Cys, and amino acid 419 from Tyr to His, respectively. These mutations resulted in the electrophoretic properties defining PGM1*7+, the PGM1*2+, and PGM1*1- alleles, respectively. Subsequent intragenic recombinational events resulted in the remaining four alleles. For two of these latter alleles (PGM1*7- and PGM1*3-), more than one type of intragenic crossover can produce the allele. These findings verify the predicted phylogeny and provide a case study in the evolution of complexity at a genetic locus.

  3. 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

  4. 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.

  5. 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

  6. Molecular Mapping of the ROSY Locus in DROSOPHILA MELANOGASTER

    PubMed Central

    Coté, Babette; Bender, Welcome; Curtis, Daniel; Chovnick, Arthur

    1986-01-01

    The DNA from the chromosomal region of the Drosophila rosy locus has been examined in 83 rosy mutant strains. Several spontaneous and radiation-induced alleles were associated with insertions and deletions, respectively. The lesions are clustered in a 4-kb region. Some of the alleles identified on the DNA map have been located on the genetic map by fine-structure recombination experiments. The genetic and molecular maps are collinear, and the alignment identifies the DNA location of the rosy control region. A rosy RNA of 4.5 kb has been identified; its 5' end lies in or near the control region. PMID:2420682

  7. 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...

  8. 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...

  9. On loops in the hyperbolic locus of the complex Hénon map and their monodromies

    NASA Astrophysics Data System (ADS)

    Arai, Zin

    2016-11-01

    We prove John Hubbard's conjecture on the topological complexity of the hyperbolic horseshoe locus of the complex Hénon map. In fact, we show that there exist several non-trivial loops in the locus which generate infinitely many mutually different monodromies. Furthermore, we prove that the dynamics of the real Hénon map is completely determined by the monodromy of the complex Hénon map, providing the parameter of the map is contained in the hyperbolic horseshoe locus.

  10. 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.

  11. 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

  12. A locus-wide approach to assessing variation in the avian MHC: the B-locus of the wild turkey

    PubMed Central

    Chaves, L D; Faile, G M; Hendrickson, J A; Mock, K E; Reed, K M

    2011-01-01

    Studies of major histocompatibility complex (MHC) diversity in non-model vertebrates typically focus on structure and sequence variation in the antigen-presenting loci: the highly variable and polymorphic class I and class IIB genes. Although these studies provide estimates of the number of genes and alleles/locus, they often overlook variation in functionally related and co-inherited genes important in the immune response. This study utilizes the sequence of the MHC B-locus derived from a commercial turkey to investigate MHC variation in wild birds. Sequences were obtained for nine interspersed MHC amplicons (non-class I/II) from each of 40 birds representing 3 subspecies of wild turkey (Meleagris gallopavo). Analysis of aligned sequences identified 238 single-nucleotide variants approximately one-third of which had minor allele frequencies >0.2 in the sampled birds. PHASE analysis identified 70 prospective MHC haplotypes in the wild turkeys, whereas a combined analysis with commercial birds identified almost 100 haplotypes in the species. Denaturing gradient gel electrophoresis (DGGE) of the class IIB loci was used to test the efficacy of single-nucleotide polymorphism (SNP) haplotyping to capture locus-wide variation. Diversity in SNP haplotypes and haplotype sharing among individuals was directly reflected in the DGGE patterns. Utilization of a reference haplotype to sequence interspersed regions of the MHC has significant advantages over other methods of surveying diversity while identifying high-frequency SNPs for genotyping. SNP haplotyping provides a means to identify both divergent haplotypes and homozygous individuals for assessment of immunological variation in wild and domestic populations. PMID:21179065

  13. A locus-wide approach to assessing variation in the avian MHC: the B-locus of the wild turkey.

    PubMed

    Chaves, L D; Faile, G M; Hendrickson, J A; Mock, K E; Reed, K M

    2011-07-01

    Studies of major histocompatibility complex (MHC) diversity in non-model vertebrates typically focus on structure and sequence variation in the antigen-presenting loci: the highly variable and polymorphic class I and class IIB genes. Although these studies provide estimates of the number of genes and alleles/locus, they often overlook variation in functionally related and co-inherited genes important in the immune response. This study utilizes the sequence of the MHC B-locus derived from a commercial turkey to investigate MHC variation in wild birds. Sequences were obtained for nine interspersed MHC amplicons (non-class I/II) from each of 40 birds representing 3 subspecies of wild turkey (Meleagris gallopavo). Analysis of aligned sequences identified 238 single-nucleotide variants approximately one-third of which had minor allele frequencies >0.2 in the sampled birds. PHASE analysis identified 70 prospective MHC haplotypes in the wild turkeys, whereas a combined analysis with commercial birds identified almost 100 haplotypes in the species. Denaturing gradient gel electrophoresis (DGGE) of the class IIB loci was used to test the efficacy of single-nucleotide polymorphism (SNP) haplotyping to capture locus-wide variation. Diversity in SNP haplotypes and haplotype sharing among individuals was directly reflected in the DGGE patterns. Utilization of a reference haplotype to sequence interspersed regions of the MHC has significant advantages over other methods of surveying diversity while identifying high-frequency SNPs for genotyping. SNP haplotyping provides a means to identify both divergent haplotypes and homozygous individuals for assessment of immunological variation in wild and domestic populations.

  14. 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

  15. A new EcoRI polymorphism at the D21S13 locus.

    PubMed

    Pulst, S M; Korenberg, J R; Greenwald, J; Carbone, M

    1990-05-01

    The D21S13 locus has shown linkage to a gene for familial Alzheimer disease (FAD) on chromosome 21 (St. George-Hyslop et al. 1987). The limited informativeness of probes for this locus have hindered precise mapping of the FAD locus and analysis of nonallelic heterogeneity in FAD (Schellenberg et al. 1988; St. George-Hyslop et al. 1987). We describe a new EcoRI polymorphism at the D21S13 locus that may be useful for the further study of FAD families.

  16. 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

  17. Genetic homogeneity at the Friedreich Ataxia locus on chromosome 9

    PubMed Central

    Chamberlain, Susan; Shaw, Jacqui; Wallis, Julie; Rowland, Alison; Chow, Larry; Farrall, Martin; Keats, Bronya; Richter, Andrea; Roy, Madeleine; Melancon, Serge; Deufel, Thomas; Berciano, José; Williamson, Robert

    1989-01-01

    Classical Friedreich ataxia, a progressive, neurodegenerative disorder involving both the central and peripheral nervous systems, has been subclassified according to the observed clinical heterogeneity. The variations in the age at onset and in the spectrum and severity of symptoms have previously been interpreted as evidence of genetic heterogeneity. We have studied the linkage between the disorder and closely linked DNA markers in families of distinct ethnic origins, including the “typical” French–Canadians and the Acadian population of Louisiana. The disease in these two populations, both of continental French origin, has a very similar initial clinical picture. However, a marked difference in the rate of progression of the obligatory symptoms after 10 years of apparent disease is observed. A total of 553 individuals from 80 families with 202 affected members have been typed with the chromosome 9 marker MCT112, which we have previously shown to be closely linked to the disease locus. Evidence for linkage was observed in all families with the generation of a combined total lod score of 25.09 at a recombination fraction of θ = .00, providing strong evidence for genetic homogeneity at this locus for the classical form of this disease. PMID:2929596

  18. A familial venous malformation locus is on chromosome 9p

    SciTech Connect

    Boon, L.M.; Mulliken, J.B.; Vikkula, M.

    1994-09-01

    Venous malformation is the most common vascular malformation affecting 0.2% of the population. Depending upon size and location, these slow-flow lesions may cause pain, anatomic distortion and threaten life. Most venous malformations occur sporadically and present as solitary lesions. For this reason, determining their pathogenic bases has proven elusive. However, venous malformations also occur in several rare syndromes, some of which demonstrate Mendelian inheritance. As a first step towards identifying the pathogenic bases for these lesions, we have mapped a locus for an autosomal dominant disorder in a three generation family that manifests as multiple cutaneous and mucosal venous malformations. This locus lies within a 24.5 cM interval on chromosome 9p, defined by the markers D9S157 and D9S163. A maximum LOD score of 4.11 at {theta} = 0.05 is obtained with several markers within the interval. The interferon gene cluster, which has previously been implicated in angiogenesis, and the multiple tumor suppressor gene, responsible for several types of malignant tumors, also lie within this interval and are potential candidates.

  19. 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).

  20. The discovery of the microphthalmia locus and its gene, Mitf.

    PubMed

    Arnheiter, Heinz

    2010-12-01

    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.

  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.

  2. 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

  3. Focus, locus, and sensus: the three dimensions of virtual experience.

    PubMed

    Waterworth, E L; Waterworth, J A

    2001-04-01

    A model of virtual/physical experience is presented, which provides a three dimensional conceptual space for virtual and augmented reality (VR and AR) comprising the dimensions of focus, locus, and sensus. Focus is most closely related to what is generally termed presence in the VR literature. When in a virtual environment, presence is typically shared between the VR and the physical world. "Breaks in presence" are actually shifts of presence away from the VR and toward the external environment. But we can also have "breaks in presence" when attention moves toward absence--when an observer is not attending to stimuli present in the virtual environment, nor to stimuli present in the surrounding physical environment--when the observer is present in neither the virtual nor the physical world. We thus have two dimensions of presence: focus of attention (between presence and absence) and the locus of attention (the virtual vs. the physical world). A third dimension is the sensus of attention--the level of arousal determining whether the observer is highly conscious or relatively unconscious while interacting with the environment. After expanding on each of these three dimensions of experience in relation to VR, we present a couple of educational examples as illustrations, and also relate our model to a suggested spectrum of evaluation methods for virtual environments.

  4. AN ENZYMATIC LOCUS PARTICIPATING IN CELLULAR DIVISION OF A YEAST

    PubMed Central

    Nickerson, Walter J.

    1954-01-01

    Growing cells of a filamentous mutant of a yeast, Candida albicans, were found to accumulate and reduce tetrazolium dyes whereas cells of the parent strain, growing as a normally budding yeast, accumulated the dye but did not reduce it. In older cultures, in which rapidly metabolizable carbohydrate has been depleted, the parent strain characteristically produces filaments. These cells, growing in the absence of cellular division, also exhibit tetrazolium reduction. The filamentous mutant synthesizes cell mass at a rate almost equal to that of the parent strain and is not distinguished therefrom in fermentation ability, nutritional requirements for growth, rate of endogenous respiration, or polysaccharide composition. These facts, in conjunction with the striking differences in tetrazolium reduction, lead to the conclusion that the morphological mutant has an impairment to a cellular oxidation mechanism at a flavoprotein locus. This locus is, then, the site at which a reaction essential for cellular division, is coupled via an oxidation-reduction to cellular metabolism. Preliminary evidence is presented providing good indication that uncoupling of cellular division (by genetic block) in the mutant or in the parent (by substrate exhaustion) results from impairment to a dissociable metal chelate mechanism which normally couples a reaction essential to cellular division to flavoprotein oxidation. PMID:13143184

  5. Variation at the TERT locus and predisposition for cancer.

    PubMed

    Baird, Duncan M

    2010-05-18

    Telomerase and the control of telomere length are intimately linked to the process of tumourigenesis in humans. Here I review the evidence that variation at the 5p15.33 locus, which contains the TERT gene (encoding the catalytic subunit of telomerase), might play a role in the determination of cancer risk. Mutations in the coding regions of TERT can affect telomerase activity and telomere length, and create severe clinical phenotypes, including bone marrow failure syndromes and a substantive increase in cancer frequency. Variants within the TERT gene have been associated with increased risk of haematological malignancies, including myelodysplastic syndrome and acute myeloid leukaemia as well as chronic lymphocytic leukaemia. Furthermore, there is good evidence from a number of independent genome-wide association studies to implicate variants at the 5p15.33 locus in cancer risk at several different sites: lung cancer, basal cell carcinoma and pancreatic cancer show strong associations, while bladder, prostate and cervical cancer and glioma also show risk alleles in this region. Thus, multiple independent lines of evidence have implicated variation in the TERT gene as a risk factor for cancer. The mechanistic basis of these risk variants is yet to be established; however, the basic biology suggests that telomere length control is a tantalising candidate mechanism underlying cancer risk.

  6. Drosophila histone locus bodies form by hierarchical recruitment of components.

    PubMed

    White, Anne E; Burch, Brandon D; Yang, Xiao-Cui; Gasdaska, Pamela Y; Dominski, Zbigniew; Marzluff, William F; Duronio, Robert J

    2011-05-16

    Nuclear bodies are protein- and RNA-containing structures that participate in a wide range of processes critical to genome function. Molecular self-organization is thought to drive nuclear body formation, but whether this occurs stochastically or via an ordered, hierarchical process is not fully understood. We addressed this question using RNAi and proteomic approaches in Drosophila melanogaster to identify and characterize novel components of the histone locus body (HLB), a nuclear body involved in the expression of replication-dependent histone genes. We identified the transcription elongation factor suppressor of Ty 6 (Spt6) and a homologue of mammalian nuclear protein of the ataxia telangiectasia-mutated locus that is encoded by the homeotic gene multisex combs (mxc) as novel HLB components. By combining genetic manipulation in both cell culture and embryos with cytological observations of Mxc, Spt6, and the known HLB components, FLICE-associated huge protein, Mute, U7 small nuclear ribonucleoprotein, and MPM-2 phosphoepitope, we demonstrated sequential recruitment and hierarchical dependency for localization of factors to HLBs during development, suggesting that ordered assembly can play a role in nuclear body formation. PMID:21576393

  7. Drosophila histone locus bodies form by hierarchical recruitment of components

    PubMed Central

    White, Anne E.; Burch, Brandon D.; Yang, Xiao-cui; Gasdaska, Pamela Y.; Dominski, Zbigniew; Marzluff, William F.

    2011-01-01

    Nuclear bodies are protein- and RNA-containing structures that participate in a wide range of processes critical to genome function. Molecular self-organization is thought to drive nuclear body formation, but whether this occurs stochastically or via an ordered, hierarchical process is not fully understood. We addressed this question using RNAi and proteomic approaches in Drosophila melanogaster to identify and characterize novel components of the histone locus body (HLB), a nuclear body involved in the expression of replication-dependent histone genes. We identified the transcription elongation factor suppressor of Ty 6 (Spt6) and a homologue of mammalian nuclear protein of the ataxia telangiectasia–mutated locus that is encoded by the homeotic gene multisex combs (mxc) as novel HLB components. By combining genetic manipulation in both cell culture and embryos with cytological observations of Mxc, Spt6, and the known HLB components, FLICE-associated huge protein, Mute, U7 small nuclear ribonucleoprotein, and MPM-2 phosphoepitope, we demonstrated sequential recruitment and hierarchical dependency for localization of factors to HLBs during development, suggesting that ordered assembly can play a role in nuclear body formation. PMID:21576393

  8. Sequence variation and haplotype structure at the human HFE locus.

    PubMed Central

    Toomajian, Christopher; Kreitman, Martin

    2002-01-01

    The HFE locus encodes an HLA class-I-type protein important in iron regulation and segregates replacement mutations that give rise to the most common form of genetic hemochromatosis. The high frequency of one disease-associated mutation, C282Y, and the nature of this disease have led some to suggest a selective advantage for this mutation. To investigate the context in which this mutation arose and gain a better understanding of HFE genetic variation, we surveyed nucleotide variability in 11.2 kb encompassing the HFE locus and experimentally determined haplotypes. We fully resequenced 60 chromosomes of African, Asian, or European ancestry as well as one chimpanzee, revealing 41 variable sites and a nucleotide diversity of 0.08%. This indicates that linkage to the HLA region has not substantially increased the level of HFE variation. Although several haplotypes are shared between populations, one haplotype predominates in Asia but is nearly absent elsewhere, causing higher than average genetic differentiation among the three major populations. Our samples show evidence of intragenic recombination, so the scarcity of recombination events within the C282Y allele class is consistent with selection increasing the frequency of a young allele. Otherwise, the pattern of variability in this region does not clearly indicate the action of positive selection at this or linked loci. PMID:12196404

  9. Deletion and Allelic Exchange of the Aspergillus fumigatus veA Locus via a Novel Recyclable Marker Module

    PubMed Central

    Krappmann, Sven; Bayram, Özgür; Braus, Gerhard H.

    2005-01-01

    Detailed evaluation of gene functions in an asexual fungus requires advanced methods of molecular biology. For the generation of targeted gene deletions in the opportunistic pathogen Aspergillus fumigatus we designed a novel blaster module allowing dominant selection of transformants due to resistance to phleomycin as well as dominant (counter)selection of a Cre recombinase-mediated marker excision event. For validation purposes we have deleted the A. fumigatus pabaA gene in a wild-type isolate by making use of this cassette. The resulting pabaA::loxP strain served as the recipient for subsequent targeting of the velvet locus. Homologous reconstitution of the deleted gene was performed by an allele whose expression is driven in a nitrogen source-dependent manner, as validated by Northern analyses. Overexpression of the veA locus in A. fumigatus does not result in any obvious phenotype, whereas the sporulation capacities of the veA null mutant are reduced on nitrate-containing medium, a phenotype that is completely restored in the reconstituted strain. PMID:16002655

  10. The maize macrohairless1 locus specifically promotes leaf blade macrohair initiation and responds to factors regulating leaf identity.

    PubMed Central

    Moose, Stephen P; Lauter, Nick; Carlson, Shawn R

    2004-01-01

    The leaf surfaces of almost all plant species possess specialized epidermal cell types that form hairs or trichomes. Maize leaves produce three distinct types of hairs, the most prominent being the macrohairs that serve as a marker for adult leaf identity and may contribute to insect resistance. This report describes the maize macrohairless1 (mhl1) locus, which promotes macrohair initiation specifically in the leaf blade. Each of seven recessive mhl1 mutant alleles significantly reduces or eliminates macrohairs in the leaf blade. The mhl1 mutations block macrohair initiation rather than interfering with macrohair morphogenesis. Genetic mapping placed mhl1 within bin 4 on chromosome 9. A second independently segregating locus was found to partially suppress the mhl1 mutant phenotype in certain genetic backgrounds. Macrohair density was observed to increase during early adult vegetative development and then progressively decline, suggesting macrohair initiation frequency is affected by factors that act throughout shoot development. Genetic analyses demonstrated that mhl1 acts in the same pathway but downstream of factors that either promote or repress adult leaf identity. Thus, mhl1 plays a key role in integrating developmental programs that regulate leaf identity during shoot development with those that specify macrohair initiation within the leaf blade. PMID:15082562

  11. A molecular basis for the association of the HLA-DRB1 locus, citrullination, and rheumatoid arthritis

    PubMed Central

    Scally, Stephen W.; Petersen, Jan; Law, Soi Cheng; Dudek, Nadine L.; Nel, Hendrik J.; Loh, Khai Lee; Wijeyewickrema, Lakshmi C.; Eckle, Sidonia B.G.; van Heemst, Jurgen; Pike, Robert N.; McCluskey, James; Toes, Rene E.; La Gruta, Nicole L.

    2013-01-01

    Rheumatoid arthritis (RA) is strongly associated with the human leukocyte antigen (HLA)-DRB1 locus that possesses the shared susceptibility epitope (SE) and the citrullination of self-antigens. We show how citrullinated aggrecan and vimentin epitopes bind to HLA-DRB1*04:01/04. Citrulline was accommodated within the electropositive P4 pocket of HLA-DRB1*04:01/04, whereas the electronegative P4 pocket of the RA-resistant HLA-DRB1*04:02 allomorph interacted with arginine or citrulline-containing epitopes. Peptide elution studies revealed P4 arginine–containing peptides from HLA-DRB1*04:02, but not from HLA-DRB1*04:01/04. Citrullination altered protease susceptibility of vimentin, thereby generating self-epitopes that are presented to T cells in HLA-DRB1*04:01+ individuals. Using HLA-II tetramers, we observed citrullinated vimentin- and aggrecan-specific CD4+ T cells in the peripheral blood of HLA-DRB1*04:01+ RA-affected and healthy individuals. In RA patients, autoreactive T cell numbers correlated with disease activity and were deficient in regulatory T cells relative to healthy individuals. These findings reshape our understanding of the association between citrullination, the HLA-DRB1 locus, and T cell autoreactivity in RA. PMID:24190431

  12. Secondary Evolution of a Self-Incompatibility Locus in the Brassicaceae Genus Leavenworthia

    PubMed Central

    Chantha, Sier-Ching; Herman, Adam C.; Platts, Adrian E.; Vekemans, Xavier; Schoen, Daniel J.

    2013-01-01

    Self-incompatibility (SI) is the flowering plant reproductive system in which self pollen tube growth is inhibited, thereby preventing self-fertilization. SI has evolved independently in several different flowering plant lineages. In all Brassicaceae species in which the molecular basis of SI has been investigated in detail, the product of the S-locus receptor kinase (SRK) gene functions as receptor in the initial step of the self pollen-rejection pathway, while that of the S-locus cysteine-rich (SCR) gene functions as ligand. Here we examine the hypothesis that the S locus in the Brassicaceae genus Leavenworthia is paralogous with the S locus previously characterized in other members of the family. We also test the hypothesis that self-compatibility in this group is based on disruption of the pollen ligand-producing gene. Sequence analysis of the S-locus genes in Leavenworthia, phylogeny of S alleles, gene expression patterns, and comparative genomics analyses provide support for both hypotheses. Of special interest are two genes located in a non-S locus genomic region of Arabidopsis lyrata that exhibit domain structures, sequences, and phylogenetic histories similar to those of the S-locus genes in Leavenworthia, and that also share synteny with these genes. These A. lyrata genes resemble those comprising the A. lyrata S locus, but they do not function in self-recognition. Moreover, they appear to belong to a lineage that diverged from the ancestral Brassicaceae S-locus genes before allelic diversification at the S locus. We hypothesize that there has been neo-functionalization of these S-locus-like genes in the Leavenworthia lineage, resulting in evolution of a separate ligand-receptor system of SI. Our results also provide support for theoretical models that predict that the least constrained pathway to the evolution of self-compatibility is one involving loss of pollen gene function. PMID:23690750

  13. 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

  14. Mutations at the SPINDLY locus of Arabidopsis alter gibberellin signal transduction.

    PubMed

    Jacobsen, S E; Olszewski, N E

    1993-08-01

    Three independent recessive mutations at the SPINDLY (SPY) locus of Arabidopsis confer resistance to the gibberellin (GA) biosynthesis inhibitor paclobutrazol. Relative to wild type, spy mutants exhibit longer hypocotyls, leaves that are a lighter green color, increased stem elongation, early flowering, parthenocarpy, and partial male sterility. All of these phenotypes are also observed when wild-type Arabidopsis plants are repeatedly treated with gibberellin A3 (GA3). The spy-1 allele is partially epistatic to the ga1-2 mutation, which causes GA deficiency. In addition, the spy-1 mutation can simultaneously suppress the effects of the ga1-2 mutation and paclobutrazol treatment, which inhibit different steps in the GA biosynthesis pathway. This observation suggests that spy-1 activates a basal level of GA signal transduction that is independent of GA. Furthermore, results from GA3 dose-response experiments suggest that GA3 and spy-1 interact in an additive manner. These results are consistent with models in which the SPY gene product regulates a portion of the GA signal transduction pathway. PMID:8400871

  15. 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

  16. 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.

  17. Linkage disequilibrium among RFLPs at the insulin-receptor locus despite intervening alu repeat sequences

    SciTech Connect

    Elbein, S.C. )

    1992-11-01

    Multiple mutations of the insulin receptor (INSR) gene have been identified in individuals with extreme insulin resistance. These mutations have included recombination events between Alu repeat units in the tyrosine kinase-encoding [beta]-chain region of the gene. To evaluate the influence of Alu and dinucleotide repetitive sequences on recombination events within the insulin receptor gene, the author examined the degree of linkage disequilibrium between RFLP pairs spanning the gene. The author established 228 independent haplotypes for seven RFLPs (two each for PstI, RsaI, and SstI and one for MspI and 172 independent haplotypes which included an additional RFLP with BglII) from 19 pedigrees. These RFLPs span >130 kb of this gene, and it was previously demonstrated that multiple Alu sequences separate RFLP pairs. Observed haplotype frequencies deviated significantly from those predicted. Pairwise analysis of RFLP showed high levels of linkage disequilibrium among RFLP in the [beta]-chain region of the insulin receptor, but not between [alpha]-chain RFLPs and those of the [beta]-chain. Disequilibrium was present among [beta]-chain RFLPs, despite separation by one or more Alu repeat sequences. The very strong linkage disequilibrium which was present in sizable regions of the INSR gene despite the presence of both Alu and microsatellite repeats suggested that these regions do not have a major impact on recombinations at this locus. 25 refs., 1 fig., 5 tabs.

  18. Quantitative Trait Locus Mapping of Melanization in the Plant Pathogenic Fungus Zymoseptoria tritici

    PubMed Central

    Lendenmann, Mark H.; Croll, Daniel; Stewart, Ethan L.; McDonald, Bruce A.

    2014-01-01

    Melanin plays an important role in virulence and antimicrobial resistance in several fungal pathogens. The wheat pathogen Zymoseptoria tritici is important worldwide, but little is known about the genetic architecture of pathogenicity, including the production of melanin. Because melanin production can exhibit complex inheritance, we used quantitative trait locus (QTL) mapping in two crosses to identify the underlying genes. Restriction site−associated DNA sequencing was used to genotype 263 (cross 1) and 261 (cross 2) progeny at ~8500 single-nucleotide polymorphisms and construct two dense linkage maps. We measured gray values, representing degrees of melanization, for single-spore colonies growing on Petri dishes by using a novel image-processing approach that enabled high-throughput phenotyping. Because melanin production can be affected by stress, each offspring was grown in two stressful environments and one control environment. We detected six significant QTL in cross 1 and nine in cross 2, with three QTL shared between the crosses. Different QTL were identified in different environments and at different colony ages. By obtaining complete genome sequences for the four parents and analyzing sequence variation in the QTL confidence intervals, we identified 16 candidate genes likely to affect melanization. One of these candidates was PKS1, a polyketide synthase gene known to play a role in the synthesis of dihydroxynaphthalene melanin. Three candidate quantitative trait nucleotides were identified in PKS1. Many of the other candidate genes were not previously associated with melanization. PMID:25360032

  19. The fester locus in Botryllus schlosseri experiences selection

    PubMed Central

    2012-01-01

    Background Allorecognition, the ability of an organism to distinguish self from non-self, occurs throughout the entire tree of life. Despite the prevalence and importance of allorecognition systems, the genetic basis of allorecognition has rarely been characterized outside the well-known MHC (Major Histocompatibility Complex) in vertebrates and SI (Self-Incompatibility) in plants. Where loci have been identified, their evolutionary history is an open question. We have previously identified the genes involved in self/non-self recognition in the colonial ascidian Botryllus schlosseri, and we can now begin to investigate their evolution. In B. schlosseri, colonies sharing 1 or more alleles of a gene called FuHC (Fusion Histocompatibility) will fuse. Protein products of a locus called fester, located ~300 kb from FuHC, have been shown to play multiple roles in the histocompatibility reaction, as activating and/or inhibitory receptors. We test whether the proteins encoded by this locus are evolving neutrally or are experiencing balancing, directional, or purifying selection. Results Nearly all of the variation in the fester locus resides within populations. The 13 housekeeping genes (12 nuclear genes and mitochondrial cytochrome oxidase I) have substantially more structure among populations within groups and among groups than fester. All polymorphism statistics (Tajima's D, Fu and Li's D* and F*) are significantly negative for the East Coast A-type alleles, and Fu and Li's F* statistic is significantly negative for the West Coast A-type alleles. These results are likely due to selection rather than demography, given that 10 of the housekeeping loci have no populations with significant values for any of the polymorphism statistics. The majority of codons in the fester proteins have ω values < 1, but 15–27 codons have > 95% posterior probability of ω values > 1. Conclusion Fester proteins are evolving non-neutrally. The polymorphism statistics are consistent with

  20. Comparative genomics enabled the isolation of the R3a late blight resistance gene in potato.

    PubMed

    Huang, Sanwen; van der Vossen, Edwin A G; Kuang, Hanhui; Vleeshouwers, Vivianne G A A; Zhang, Ningwen; Borm, Theo J A; van Eck, Herman J; Baker, Barbara; Jacobsen, Evert; Visser, Richard G F

    2005-04-01

    Comparative genomics provides a tool to utilize the exponentially increasing sequence information from model plants to clone agronomically important genes from less studied crop species. Plant disease resistance (R) loci frequently lack synteny between related species of cereals and crucifers but appear to be positionally well conserved in the Solanaceae. In this report, we adopted a local RGA approach using genomic information from the model Solanaceous plant tomato to isolate R3a, a potato gene that confers race-specific resistance to the late blight pathogen Phytophthora infestans. R3a is a member of the R3 complex locus on chromosome 11. Comparative analyses of the R3 complex locus with the corresponding I2 complex locus in tomato suggest that this is an ancient locus involved in plant innate immunity against oomycete and fungal pathogens. However, the R3 complex locus has evolved after divergence from tomato and the locus has experienced a significant expansion in potato without disruption of the flanking colinearity. This expansion has resulted in an increase in the number of R genes and in functional diversification, which has probably been driven by the co-evolutionary history between P. infestans and its host potato. Constitutive expression was observed for the R3a gene, as well as some of its paralogues whose functions remain unknown.

  1. Development of a high-resolution melting marker for selecting Fusarium crown and root rot resistance in tomato.

    PubMed

    Kim, Bichseam; Kim, Nahui; Kim, Jun Young; Kim, Byung Sup; Jung, Hee-Jeong; Hwang, Indoek; Noua, Ill-Sup; Sim, Sung-Chur; Park, Younghoon

    2016-03-01

    Fusarium crown and root rot is a severe fungal disease of tomato caused by Fusarium oxysporum f. sp. radicis-lycopersici (FORL). In this study, the genomic location of the FORL-resistance locus was determined using a set of molecular markers on chromosome 9 and an F2 population derived from FORL-resistant inbred 'AV107-4' (Solanum lycopersicum) × susceptible 'L3708' (Solanum pimpinellifolium). Bioassay performed using Korean FORL strain KACC 40031 showed single dominant inheritance of FORL resistance in the F2 population. In all, 13 polymerase chain reaction-based markers encompassing approximately 3.6-72.0 Mb of chromosome 9 were developed based on the Tomato-EXPEN 2000 map and SolCAP Tomato single nucleotide polymorphism array analysis. These markers were genotyped on 345 F2 plants, and the FORL-resistance locus was found to be present on a pericentromeric region of suppressed chromosomal recombination in chromosome 9. The location of the FORL-resistance locus was further confirmed by testing these markers against diverse commercial tomato and stock cultivars resistant to FORL. A restriction fragment length polymorphism marker, PNU-D4, located at approximately 6.1 Mb of chromosome 9 showed the highest match with the resistance locus and was used for conducting high-resolution melting analysis for marker-assisted selection of FORL resistance.

  2. 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...

  3. 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 ...

  4. 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…

  5. Age-Dependent and Age-Independent Measures of Locus of Control.

    ERIC Educational Resources Information Center

    Sherman, Lawrence W.; Hofmann, Richard

    Using a longitudinal data set obtained from 169 pre-adolescent children between the ages of 8 and 13 years, this study statistically divided locus of control into two independent components. The first component was noted as "age-dependent" (AD) and was determined by predicted values generated by regressing children's ages onto their locus of…

  6. 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…

  7. Differences in Self-Concept and Locus of Control among Women Who Seek Abortions.

    ERIC Educational Resources Information Center

    Thompson, Linda V.; Robinson, Sharon E.

    1986-01-01

    Three groups of women who varied in abortion status were formed to investigate the self-concept and locus of control of a total of 90 women. No significant differences in self-concept were found among the three groups, nor was there a relationship between locus of control and repeated abortion. (Author/ABB)

  8. 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…

  9. Locus ceruleus neurons in people with autism contain no histochemically-detectable mercury.

    PubMed

    Pamphlett, Roger; Kum Jew, Stephen

    2016-02-01

    Exposure to environmental mercury has been proposed to play a part in autism. Mercury is selectively taken up by the human locus ceruleus, a region of the brain that has been implicated in autism. We therefore looked for the presence of mercury in the locus ceruleus of people who had autism, using the histochemical technique of autometallography which can detect nanogram amounts of mercury in tissues. In addition, we sought evidence of damage to locus ceruleus neurons in autism by immunostaining for hyperphosphorylated tau. No mercury was found in any neurons of the locus ceruleus of 6 individuals with autism (5 male, 1 female, age range 16-48 years). Mercury was present in locus ceruleus neurons in 7 of 11 (64%) age-matched control individuals who did not have autism, which is significantly more than in individuals with autism. No increase in numbers of locus ceruleus neurons containing hyperphosphorylated tau was detected in people with autism. In conclusion, most people with autism have not been exposed early in life to quantities of mercury large enough to be found later in adult locus ceruleus neurons. Human locus ceruleus neurons are sensitive indicators of mercury exposure, and mercury appears to remain in these neurons indefinitely, so these findings do not support the hypothesis that mercury neurotoxicity plays a role in autism.

  10. 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…

  11. Locus of Control and the ACT as Predictors of Success for Black College Students.

    ERIC Educational Resources Information Center

    Johnson, Darwin; Napier, Lee

    The influence of locus of control (LC) and American College Testing (ACT) scores in predicting grade point average (GPA) was investigated with college freshmen at a predominantly and historically black campus in Mississippi. A total of 322 freshmen were administered the Rotter Locus of Control Inventory during the first month of school. The ACT…

  12. 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…

  13. 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…

  14. 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…

  15. 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…

  16. 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…

  17. Mapping of panda plumage color locus on the microsatellite linkage map of the Japanese quail

    PubMed Central

    Miwa, Mitsuru; Inoue-Murayama, Miho; Kobayashi, Naoki; Kayang, Boniface Baboreka; Mizutani, Makoto; Takahashi, Hideaki; Ito, Shin'ichi

    2006-01-01

    Background Panda (s) is an autosomal recessive mutation, which displays overall white plumage color with spots of wild-type plumage in the Japanese quail (Coturnix japonica). In a previous study, the s locus was included in the same linkage group as serum albumin (Alb) and vitamin-D binding protein (GC) which are mapped on chicken (Gallus gallus) chromosome 4 (GGA4). In this study, we mapped the s locus on the microsatellite linkage map of the Japanese quail by linkage analysis. Results Segregation data on the s locus were obtained from three-generation families (n = 106). Two microsatellite markers derived from the Japanese quail chromosome 4 (CJA04) and three microsatellite markers derived from GGA4 were genotyped in the three-generation families. We mapped the s locus between GUJ0026 and ABR0544 on CJA04. By comparative mapping with chicken, this locus was mapped between 10.0 Mb and 14.5 Mb region on GGA4. In this region, the endothelin receptor B subtype 2 gene (EDNRB2), an avian-specific paralog of the mammalian endothelin receptor B gene (EDNRB), is located. Because EDNRB is responsible for aganglionic megacolon and spot coat color in mouse, rat and equine, EDNRB2 is suggested to be a candidate gene for the s locus. Conclusion The s locus and the five microsatellite markers were mapped on CJA04 of the Japanese quail. EDNRB2 was suggested to be a candidate gene for the s locus. PMID:16405738

  18. A locus necessary for the transport and catabolism of erythritol in Sinorhizobium meliloti.

    PubMed

    Geddes, Barney A; Pickering, Brad S; Poysti, Nathan J; Collins, Heather; Yudistira, Harry; Oresnik, Ivan J

    2010-10-01

    In this work we have genetically defined an erythritol utilization locus in Sinorhizobium meliloti. A cosmid containing the locus was isolated by complementation of a transposon mutant and was subsequently mutagenized using Tn5 : : B20. The locus was found to consist of five transcriptional units, each of which was necessary for the utilization of erythritol. Genetic complementation experiments using genes putatively annotated as erythritol catabolic genes clearly showed that, of the 17 genes at this locus, six genes are not necessary for the utilization of erythritol as a sole carbon source. The remaining genes encode EryA, EryB, EryC and TpiB as well as an uncharacterized ABC-type transporter. Transport experiments using labelled erythritol showed that components of the ABC transporter are necessary for the uptake of erythritol. The locus also contains two regulators: EryD, a SorC class regulator, and SMc01615, a DeoR class regulator. Quantitative RT-PCR experiments showed that each of these regulators negatively regulates its own transcription. In addition, induction of the erythritol locus was dependent upon EryD and a product of erythritol catabolism. Further characterization of polar mutations revealed that in addition to erythritol, the locus contains determinants for adonitol and l-arabitol utilization. The context of the mutations suggests that the locus is important for both the transport and catabolism of adonitol and l-arabitol.

  19. 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…

  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. Rational-Emotive Education, Self-Concept, and Locus of Control among Learning-Disabled Students.

    ERIC Educational Resources Information Center

    Omizo, Michael M.; And Others

    1986-01-01

    Investigated effects of a rational-emotive education (REE) program on learning-disabled adolescents' (N=60) self-concept and locus of control. Results suggest that the REE intervention strategy is an effective approach to helping learning-disabled adolescents enhance some aspects of self-concept and develop a more internal locus of control…

  2. 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,…

  3. 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…

  4. 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…

  5. 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…

  6. 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…

  7. Locus of Control and Value Orientations of Undergraduate and Graduate Students in a Teacher Education Program.

    ERIC Educational Resources Information Center

    Linder, Fredric; And Others

    The relationship between locus of control and value orientation was studied in adult teacher education majors. The Rotter Internal External Locus of Control Scale and Rokeach Value Survey were administered to 413 undergraduate and graduate students ranging in age from 18 years to over 50. Demographic data were also collected. The results showed…

  8. Description and nomenclature of Neisseria meningitidis capsule locus.

    PubMed

    Harrison, Odile B; Claus, Heike; Jiang, Ying; Bennett, Julia S; Bratcher, Holly B; Jolley, Keith A; Corton, Craig; Care, Rory; Poolman, Jan T; Zollinger, Wendell D; Frasch, Carl E; Stephens, David S; Feavers, Ian; Frosch, Matthias; Parkhill, Julian; Vogel, Ulrich; Quail, Michael A; Bentley, Stephen D; Maiden, Martin C J

    2013-04-01

    Pathogenic Neisseria meningitidis isolates contain a polysaccharide capsule that is the main virulence determinant for this bacterium. Thirteen capsular polysaccharides have been described, and nuclear magnetic resonance spectroscopy has enabled determination of the structure of capsular polysaccharides responsible for serogroup specificity. Molecular mechanisms involved in N. meningitidis capsule biosynthesis have also been identified, and genes involved in this process and in cell surface translocation are clustered at a single chromosomal locus termed cps. The use of multiple names for some of the genes involved in capsule synthesis, combined with the need for rapid diagnosis of serogroups commonly associated with invasive meningococcal disease, prompted a requirement for a consistent approach to the nomenclature of capsule genes. In this report, a comprehensive description of all N. meningitidis serogroups is provided, along with a proposed nomenclature, which was presented at the 2012 XVIIIth International Pathogenic Neisseria Conference.

  9. 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

  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. 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.

  12. 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.

  13. 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

  14. 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.

  15. Locus Coeruleus in time with the making of memories.

    PubMed

    Sara, Susan J

    2015-12-01

    Over the past decades studies of the neurobiology of memory were largely restricted to consideration of cellular and molecular events taking place immediately or shortly after training, the so-called consolidation period. More recent views have recognized that the memory process includes sensory processing, orienting of attention, retrieval, encoding, and subsequent consolidation. Advances in biotechnology are providing new tools to gain insights at every level of the memory process. New data from experiments employing high definition fMRI are confirming the role of the Locus Coeruleus (LC) noradrenergic system in reorienting of attention and in cognitive flexibility. Electrophysiological studies show new task-related activation of these neurons and learning-related off line activation and suggest a temporal relationship between LC spiking and cortical oscillations in the theta and gamma frequencies. PMID:26241632

  16. 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

  17. 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

  18. Homozygosity mapping of the Achromatopsia locus in the Pingelapese.

    PubMed

    Winick, J D; Blundell, M L; Galke, B L; Salam, A A; Leal, S M; Karayiorgou, M

    1999-06-01

    Achromatopsia, or total color blindness (also referred to as "rod monochromacy"), is a severe retinal disorder characterized clinically by an inability to distinguish colors, impaired visual acuity in daylight, photophobia, and nystagmus. Inherited as an autosomal recessive trait, achromatopsia is rare in the general population (1:20,000-1:50,000). Among the Pingelapese people of the Eastern Caroline Islands, however, the disorder occurs at an extremely high frequency, as recounted in Oliver Sacks's popular book The Island of the Colorblind: 4%-10% of this island population have the disorder and approximately 30% carry the gene. This extraordinary enrichment of the disease allele most likely resulted from a sharp reduction in population in the late 18th century, in the aftermath of a typhoon and subsequent geographic and cultural isolation. To obtain insights into the genetic basis of achromatopsia, as well as into the genetic history of this region of Micronesia, a genomewide search for linkage was performed in three Pingelapese kindreds with achromatopsia. A two-step search was used with a DNA pooling strategy, followed by genotyping of individual family members. Genetic markers that displayed a shift toward homozygosity in the affected DNA pool were used to genotype individual members of the kindreds, and an achromatopsia locus was identified on 8q21-q22. A maximal multipoint LOD score of 9.5 was observed with marker D8S1707. Homozygosity was seen for three adjacent markers (D8S275, D8S1119, and D8S1707), whereas recombination was observed with the flanking markers D8S1757 and D8S270, defining the outer boundaries of the disease-gene locus that spans a distance of <6.5cM. PMID:10330355

  19. Surfeit locus gene homologs are widely distributed in invertebrate genomes.

    PubMed

    Armes, N; Fried, M

    1996-10-01

    The mouse Surfeit locus contains six sequence-unrelated genes (Surf-1 to -6) arranged in the tightest gene cluster so far described for mammals. The organization and juxtaposition of five of the Surfeit genes (Surf-1 to -5) are conserved between mammals and birds, and this may reflect a functional or regulatory requirement for the gene clustering. We have undertaken an evolutionary study to determine whether the Surfeit genes are conserved and clustered in invertebrate genomes. Drosophila melanogaster and Caenorhabditis elegans homologs of the mouse Surf-4 gene, which encodes an integral membrane protein associated with the endoplasmic reticulum, have been isolated. The amino acid sequences of the Drosophila and C. elegans homologs are highly conserved in comparison with the mouse Surf-4 protein. In particular, a dilysine motif implicated in endoplasmic reticulum localization of the mouse protein is conserved in the invertebrate homologs. We show that the Drosophila Surf-4 gene, which is transcribed from a TATA-less promoter, is not closely associated with other Drosophila Surfeit gene homologs but rather is located upstream from sequences encoding a homolog of a yeast seryl-tRNA synthetase protein. There are at least two closely linked Surf-3/rpL7a genes or highly polymorphic alleles of a single Surf-3/rpL7a gene in the C. elegans genome. The chromosomal locations of the C. elegans Surf-1, Surf-3/rpL7a, and Surf-4 genes have been determined. In D. melanogaster the Surf-3/rpL7a, Surf-4, and Surf-5 gene homologs and in C. elegans the Surf-1, Surf-3/rpL7a, Surf-4, and Surf-5 gene homologs are located on completely different chromosomes, suggesting that any requirement for the tight clustering of the genes in the Surfeit locus is restricted to vertebrate lineages.

  20. 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.

  1. The potato R locus codes for dihydroflavonol 4-reductase.

    PubMed

    Zhang, Yongfei; Cheng, Shuping; De Jong, Darlene; Griffiths, Helen; Halitschke, Rayko; De Jong, Walter

    2009-09-01

    The potato R locus is required for the production of red pelargonidin-based anthocyanin pigments in potato (Solanum tuberosum L.). Red color also requires tissue-specific regulatory genes, such as D (for expression in tuber skin) and F (expression in flowers). A related locus, P, is required for production of blue/purple anthocyanins; P is epistatic to R. We have previously reported that the dihydroflavonol 4-reductase gene (dfr) co-segregates with R. To test directly whether R corresponds to dfr, we placed the allele of dfr associated with red color under the control of the CaMV 35S promoter and introduced it into the potato cultivar Prince Hairy (genotype dddd rrrr P-), which has white tubers and pale blue flowers. Transgenic Prince Hairy tubers remained white, but flower color changed to purple. Three independent transgenic lines, as well as a vector-transformed line, were then crossed with the red-skinned variety Chieftain (genotype D-R-pppp), to establish populations that segregated for D, R, P, and the dfr transgene or empty vector. Markers were used to genotype progeny at D and R. Progeny carrying the empty vector in the genetic background D-rrrr produced white or purple tubers, while progeny with the same genotype and the dfr transgene produced red or purple tubers. HPLC and LC-MS/MS analyses of anthocyanins present in Chieftain and in a red-skinned progeny clone with the dfr transgene in a D-rrrr background revealed no qualitative differences. Thus, dfr can fully complement R, both in terms of tuber color and anthocyanin composition.

  2. PAHdb 2003: what a locus-specific knowledgebase can do.

    PubMed

    Scriver, Charles R; Hurtubise, Mélanie; Konecki, David; Phommarinh, Manyphong; Prevost, Lynne; Erlandsen, Heidi; Stevens, Ray; Waters, Paula J; Ryan, Shannon; McDonald, David; Sarkissian, Christineh

    2003-04-01

    PAHdb, a legacy of and resource in genetics, is a relational locus-specific database (http://www.pahdb.mcgill.ca). It records and annotates both pathogenic alleles (n = 439, putative disease-causing) and benign alleles (n = 41, putative untranslated polymorphisms) at the human phenylalanine hydroxylase locus (symbol PAH). Human alleles named by nucleotide number (systematic names) and their trivial names receive unique identifier numbers. The annotated gDNA sequence for PAH is typical for mammalian genes. An annotated gDNA sequence is numbered so that cDNA and gDNA sites are interconvertable. A site map for PAHdb leads to a large array of secondary data (attributes): source of the allele (submitter, publication, or population); polymorphic haplotype background; and effect of the allele as predicted by molecular modeling on the phenylalanine hydroxylase enzyme (EC 1.14.16.1) or by in vitro expression analysis. The majority (63%) of the putative pathogenic PAH alleles are point mutations causing missense in translation of which few have a primary effect on PAH enzyme kinetics. Most apparently have a secondary effect on its function through misfolding, aggregation, and intracellular degradation of the protein. Some point mutations create new splice sites. A subset of primary PAH mutations that are tetrahydrobiopterin-responsive is highlighted on a Curators' Page. A clinical module describes the corresponding human clinical disorders (hyperphenylalaninemia [HPA] and phenylketonuria [PKU]), their inheritance, and their treatment. PAHdb contains data on the mouse gene (Pah) and on four orthologous mutant mouse models and their use (for example, in research on oral treatment of PKU with the enzyme phenylalanine ammonia lyase [EC 4.3.1.5]).

  3. Homozygosity mapping of the Achromatopsia locus in the Pingelapese.

    PubMed Central

    Winick, J D; Blundell, M L; Galke, B L; Salam, A A; Leal, S M; Karayiorgou, M

    1999-01-01

    Achromatopsia, or total color blindness (also referred to as "rod monochromacy"), is a severe retinal disorder characterized clinically by an inability to distinguish colors, impaired visual acuity in daylight, photophobia, and nystagmus. Inherited as an autosomal recessive trait, achromatopsia is rare in the general population (1:20,000-1:50,000). Among the Pingelapese people of the Eastern Caroline Islands, however, the disorder occurs at an extremely high frequency, as recounted in Oliver Sacks's popular book The Island of the Colorblind: 4%-10% of this island population have the disorder and approximately 30% carry the gene. This extraordinary enrichment of the disease allele most likely resulted from a sharp reduction in population in the late 18th century, in the aftermath of a typhoon and subsequent geographic and cultural isolation. To obtain insights into the genetic basis of achromatopsia, as well as into the genetic history of this region of Micronesia, a genomewide search for linkage was performed in three Pingelapese kindreds with achromatopsia. A two-step search was used with a DNA pooling strategy, followed by genotyping of individual family members. Genetic markers that displayed a shift toward homozygosity in the affected DNA pool were used to genotype individual members of the kindreds, and an achromatopsia locus was identified on 8q21-q22. A maximal multipoint LOD score of 9.5 was observed with marker D8S1707. Homozygosity was seen for three adjacent markers (D8S275, D8S1119, and D8S1707), whereas recombination was observed with the flanking markers D8S1757 and D8S270, defining the outer boundaries of the disease-gene locus that spans a distance of <6.5cM. PMID:10330355

  4. 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...

  5. Development of self-compatible B. rapa by RNAi-mediated S locus gene silencing.

    PubMed

    Jung, Hee-Jeong; Jung, Hyo-Jin; Ahmed, Nasar Uddin; Park, Jong-In; Kang, Kwon-Kyoo; Hur, Yoonkang; Lim, Yong-Pyo; Nou, Ill-Sup

    2012-01-01

    The self-incompatibility (SI) system is genetically controlled by a single polymorphic locus known as the S-locus in the Brassicaceae. Pollen rejection occurs when the stigma and pollen share the same S-haplotype. Recognition of S-haplotype specificity has recently been shown to involve at least two S-locus genes, S-receptor kinase (SRK) and S-locus protein 11 or S locus Cysteine-rich (SP11/SCR) protein. Here, we examined the function of S(60), one SP11/SCR allele of B. rapa cv. Osome, using a RNAi-mediated gene silencing approach. The transgenic RNAi lines were highly self-compatible, and this trait was stable in subsequent generations, even after crossing with other commercial lines. These findings also suggested that the resultant self-compatibility could be transferred to commercial cultivars with the desired performances in B. rapa.

  6. A 27-locus STR assay to meet all United States and European law enforcement agency standards.

    PubMed

    Schumm, James W; Gutierrez-Mateo, Cristina; Tan, Eugene; Selden, Richard

    2013-11-01

    Different national and international agencies have selected specific STR sets for forensic database use. To enhance database comparison across national and international borders, a 27-locus multiplex system was developed comprising all 15 STR loci of the European standard set, the current 13 STR loci of the CODIS core, the proposed 22 STR loci of the expanded CODIS core, 4 additional commonly used STR loci, and the amelogenin locus. Development required iterative primer design to resolve primer-related artifacts, amplicon sizing, and locus-to-locus balance issues. The 19.5-min assay incorporated newly developed six-dye chemistry analyzed using a novel microfluidic electrophoresis instrument capable of simultaneous detection and discrimination of 8 or more fluorescent dyes. The 27-locus multiplex offers the potential for a new international STR standard permitting laboratories in any jurisdiction to use a single reaction to determine profiles for loci they typically generate plus an expanded common STR profiling set of global interest.

  7. Development of Self-Compatible B. rapa by RNAi-Mediated S Locus Gene Silencing

    PubMed Central

    Jung, Hee-Jeong; Jung, Hyo-Jin; Ahmed, Nasar Uddin; Park, Jong-In; Kang, Kwon-Kyoo; Hur, Yoonkang; Lim, Yong-Pyo; Nou, Ill-Sup

    2012-01-01

    The self-incompatibility (SI) system is genetically controlled by a single polymorphic locus known as the S-locus in the Brassicaceae. Pollen rejection occurs when the stigma and pollen share the same S-haplotype. Recognition of S-haplotype specificity has recently been shown to involve at least two S-locus genes, S-receptor kinase (SRK) and S-locus protein 11 or S locus Cysteine-rich (SP11/SCR) protein. Here, we examined the function of S60, one SP11/SCR allele of B. rapa cv. Osome, using a RNAi-mediated gene silencing approach. The transgenic RNAi lines were highly self-compatible, and this trait was stable in subsequent generations, even after crossing with other commercial lines. These findings also suggested that the resultant self-compatibility could be transferred to commercial cultivars with the desired performances in B. rapa. PMID:23145180

  8. 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

  9. Evidence for the existence of a fourth dominantly inherited spinocerebellar ataxia locus

    SciTech Connect

    Lopes-Cendes, I. Montreal Neurological Institute and Hospital, Quebec McGill Univ., Quebec ); Andermann, E. McGill Univ., Quebec ); Rouleau, G.A. Montreal Neurological Institute and Hospital, Quebec )

    1994-05-01

    The autosomal dominantly inherited spinocerebellar ataxias (SCAs) are a heterogeneous group of disorders. To date, three loci have been identified: The SCA1 locus (on chr 6p), the SCA2 locus (on chr 12q), and more recently a Machado-Joseph disease (MJD) locus (on chr 14q). The authors have studied one large French-Canadian kindred with four generations of living affected individuals segregating an autosomal dominant form of SCA. Linkage analysis using anonymous DNA markers that flank the three previously described loci significantly exclude the French-Canadian kindred from the SCA1, SCA2, and MJD loci. Therefore, a fourth, still unmapped SCA locus remains to be identified. In addition, the unique clinical phenotype present in all affected individuals of the French-Canadian kindred might be characteristic of this still unmapped SCA locus. 34 refs., 2 figs., 2 tabs.

  10. 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

  11. Phenotypic and fine genetic characterization of the D locus controlling fruit acidity in peach

    PubMed Central

    2009-01-01

    Background Acidity is an essential component of the organoleptic quality of fleshy fruits. However, in these fruits, the physiological and molecular mechanisms that control fruit acidity remain unclear. In peach the D locus controls fruit acidity; low-acidity is determined by the dominant allele. Using a peach progeny of 208 F2 trees, the D locus was mapped to the proximal end of linkage group 5 and co-localized with major QTLs involved in the control of fruit pH, titratable acidity and organic acid concentration and small QTLs for sugar concentration. To investigate the molecular basis of fruit acidity in peach we initiated the map-based cloning of the D locus. Results In order to generate a high-resolution linkage map in the vicinity of the D locus, 1,024 AFLP primer combinations were screened using DNA of bulked acid and low-acid segregants. We also screened a segregating population of 1,718 individuals for chromosomal recombination events linked to the D locus and identified 308 individuals with recombination events close to D. Using these recombinant individuals we delimited the D locus to a genetic interval of 0.4 cM. We also constructed a peach BAC library of 52,000 clones with a mean insert size of 90 kb. The screening of the BAC library with markers tightly linked to D locus indicated that 1 cM corresponds to 250 kb at the vicinity of the D locus. Conclusion In the present work we presented the first high-resolution genetic map of D locus in peach. We also constructed a peach BAC library of approximately 15× genome equivalent. This fine genetic and physical characterization of the D locus is the first step towards the isolation of the gene(s) underlying fruit acidity in peach. PMID:19445673

  12. 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

  13. Antimicrobial (Drug) Resistance

    MedlinePlus

    ... Antimicrobial (Drug) Resistance Antibiotic-Resistant Mycobacterium tuberculosis (TB) Methicillin-Resistant Staphylococcus aureus (MRSA) Vancomycin-Resistant Enterococci (VRE) Multidrug-Resistant Neisseria ...

  14. 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.

  15. 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.

  16. 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

  17. Mapping of isolate-specific QTLs for clubroot resistance in Chinese cabbage (Brassica rapa L. ssp. pekinensis).

    PubMed

    Sakamoto, Koji; Saito, Atsuo; Hayashida, Nobuaki; Taguchi, Goro; Matsumoto, Etsuo

    2008-09-01

    A number of clubroot resistant (CR) Chinese cabbage cultivars have been developed in Japan using resistant genes from CR European fodder turnips (B. rapa ssp. rapifera). Clubroot resistance in European fodder turnips are known to be controlled by the combined action of several dominant resistance genes. We have developed three Chinese cabbage clubroot-resistant doubled haploid (DH) lines--T136-8, K10, and C9--which express resistance in different manners against two isolates of Plasmodiophora brassicae, M85 and K04. Depending on the isolates, we identified two CR loci, CRk and CRc. CRk was identified by quantitative trait loci (QTL) analysis of an F(2) population derived from a cross between K10 and Q5. This locus showed resistance to both isolates and is located close to Crr3 in linkage group R3. The other locus, CRc was identified by QTL analysis of an F(2) population derived from a cross between C9 and susceptible DH line, 6R. This locus was mapped to linkage group R2 and is independent from any published CR loci. We developed sequence-tagged site markers linked to this locus.

  18. 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 ...

  19. Comparative mapping reveals partial conservation of synteny at the apomixis locus in Paspalum spp.

    PubMed

    Pupilli, F; Martinez, E J; Busti, A; Calderini, O; Quarin, C L; Arcioni, S

    2004-01-01

    In plants, gametophytic apomixis is a form of asexual reproduction that leads to the formation of seed-derived offspring that are genetically identical to the mother plant. A common set of RFLP markers, including five rice anchor markers previously shown to be linked to apomixis in Paspalum simplex, were used to detect linkage with apomixis in P. notatum and P. malacophyllum. A comparative map of the region around the apomixis locus was constructed for the three Paspalum species, and compared to the rice map. The locus that controls apomixis in P. simplex was almost completely conserved in the closely related species P. malacophyllum, whereas it was only partially represented in the distantly related species P. notatum. Although strong synteny of markers was noted between this locus and a portion of rice chromosome 12 in both P. simplex and P. malacophyllum, the same locus in P. notatum was localized to a hybrid chromosome which carries markers that map to rice chromosomes 2 and 12. All three Paspalum species showed recombination suppression at the apomixis locus; in the case of P. notatum, this might be due to a heterozygosity for a translocation that most probably negatively interferes with chromosomal pairing near the locus. A common set of markers that show linkage with apomixis in all three Paspalum species define a portion of the apomixis-controlling locus that is likely to contain genes critical for apomictic reproduction.

  20. 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.

  1. Organization and evolutionary trajectory of the mating type (MAT) locus in dermatophyte and dimorphic fungal pathogens.

    PubMed

    Li, Wenjun; Metin, Banu; White, Theodore C; Heitman, Joseph

    2010-01-01

    Sexual reproduction in fungi is governed by a specialized genomic region, the mating type (MAT) locus, whose gene identity, organization, and complexity are diverse. We identified the MAT locus of five dermatophyte fungal pathogens (Microsporum gypseum, Microsporum canis, Trichophyton equinum, Trichophyton rubrum, and Trichophyton tonsurans) and a dimorphic fungus, Paracoccidioides brasiliensis, and performed phylogenetic analyses. The identified MAT locus idiomorphs of M. gypseum control cell type identity in mating assays, and recombinant progeny were produced. Virulence tests in Galleria mellonella larvae suggest the two mating types of M. gypseum may have equivalent virulence. Synteny analysis revealed common features of the MAT locus shared among these five dermatophytes: namely, a small size ( approximately 3 kb) and a novel gene arrangement. The SLA2, COX13, and APN2 genes, which flank the MAT locus in other Ascomycota are instead linked on one side of the dermatophyte MAT locus. In addition, the transcriptional orientations of the APN2 and COX13 genes are reversed compared to the dimorphic fungi Histoplasma capsulatum, Coccidioides immitis, and Coccidioides posadasii. A putative transposable element, pogo, was found to have inserted in the MAT1-2 idiomorph of one P. brasiliensis strain but not others. In conclusion, the evolution of the MAT locus of the dermatophytes and dimorphic fungi from the last common ancestor has been punctuated by both gene acquisition and expansion, and asymmetric gene loss. These studies further support a foundation to develop molecular and genetic tools for dermatophyte and dimorphic human fungal pathogens. PMID:19880755

  2. A third locus for autosomal dominant cerebellar ataxia Type I maps to chromosome 14q24. 3-qter: Evidence for the existence of a fourth locus

    SciTech Connect

    Stevanin, G.; Guern, E.L.; Ravise, N.; Chneiweiss, H.; Duerr, A.; Cancel, G.; Vignal, A.; Boch, A.L.; Ruberg, M.; Penet, C.; Pothin, Y.; Lagroua, I.; Haguenau, M.; Rancurel, G.; Weissenbach, J.; Agid, Y.; Brice, A.

    1994-01-01

    The autosomal dominant cerebellar ataxias (ADCA) type I are a group of neurological disorders that are clinically and genetically heterogeneous. Two genes implicated in the disease, SCA1 (spinal cerebellar ataxia 1) and SCA2, are already localized. The authors have mapped a third locus to chromosome 14q24.3-qter, by linkage analysis in a non-SCA1/non-SCA2 family and have confirmed its existence in a second such family. The authors suggest designating this new locus [open quotes]SCA3.[close quotes] Combined analysis of the two families restricted the SCA3 locus to a 15-cM interval between markers D14S67 and D14S81. The gene for Machado-Joseph disease (MJD), a clinically different form of ADCA type I, has been recently assigned to chromosome 14q24.3-q32. Although the SCA3 locus is within the MJD region, linkage analyses cannot yet demonstrate whether they result from mutations of the same gene. Linkage to all three loci (SCA1, SCA2, and SCA3) was excluded in another family, which indicates the existence of a fourth ADCA type I locus. 36 refs., 4 figs., 3 tabs.

  3. Transgenic resistance.

    PubMed

    Cillo, Fabrizio; Palukaitis, Peter

    2014-01-01

    Transgenic resistance to plant viruses is an important technology for control of plant virus infection, which has been demonstrated for many model systems, as well as for the most important plant viruses, in terms of the costs of crop losses to disease, and also for many other plant viruses infecting various fruits and vegetables. Different approaches have been used over the last 28 years to confer resistance, to ascertain whether particular genes or RNAs are more efficient at generating resistance, and to take advantage of advances in the biology of RNA interference to generate more efficient and environmentally safer, novel "resistance genes." The approaches used have been based on expression of various viral proteins (mostly capsid protein but also replicase proteins, movement proteins, and to a much lesser extent, other viral proteins), RNAs [sense RNAs (translatable or not), antisense RNAs, satellite RNAs, defective-interfering RNAs, hairpin RNAs, and artificial microRNAs], nonviral genes (nucleases, antiviral inhibitors, and plantibodies), and host-derived resistance genes (dominant resistance genes and recessive resistance genes), and various factors involved in host defense responses. This review examines the above range of approaches used, the viruses that were tested, and the host species that have been examined for resistance, in many cases describing differences in results that were obtained for various systems developed in the last 20 years. We hope this compilation of experiences will aid those who are seeking to use this technology to provide resistance in yet other crops, where nature has not provided such.

  4. Resistance mechanisms

    PubMed Central

    Cag, Yasemin; Caskurlu, Hulya; Fan, Yanyan; Cao, Bin

    2016-01-01

    By definition, the terms sepsis and septic shock refer to a potentially fatal infectious state in which the early administration of an effective antibiotic is the most significant determinant of the outcome. Because of the global spread of resistant bacteria, the efficacy of antibiotics has been severely compromised. S. pneumonia, Escherichia coli (E. coli), Klebsiella, Acinetobacter, and Pseudomonas are the predominant pathogens of sepsis and septic shock. It is common for E. coli, Klebsiella, Acinetobacter and Pseudomonas to be resistant to multiple drugs. Multiple drug resistance is caused by the interplay of multiple resistance mechanisms those emerge via the acquisition of extraneous resistance determinants or spontaneous mutations. Extended-spectrum beta-lactamases (ESBLs), carbapenemases, aminoglycoside-modifying enzymes (AMEs) and quinolone resistance determinants are typically external and disseminate on mobile genetic elements, while porin-efflux mechanisms are activated by spontaneous modifications of inherited structures. Porin and efflux mechanisms are frequent companions of multiple drug resistance in Acinetobacter and P. aeruginosa, but only occasionally detected among E. coli and Klebsiella. Antibiotic resistance became a global health threat. This review examines the major resistance mechanisms of the leading microorganisms of sepsis. PMID:27713884

  5. Transgenic resistance.

    PubMed

    Cillo, Fabrizio; Palukaitis, Peter

    2014-01-01

    Transgenic resistance to plant viruses is an important technology for control of plant virus infection, which has been demonstrated for many model systems, as well as for the most important plant viruses, in terms of the costs of crop losses to disease, and also for many other plant viruses infecting various fruits and vegetables. Different approaches have been used over the last 28 years to confer resistance, to ascertain whether particular genes or RNAs are more efficient at generating resistance, and to take advantage of advances in the biology of RNA interference to generate more efficient and environmentally safer, novel "resistance genes." The approaches used have been based on expression of various viral proteins (mostly capsid protein but also replicase proteins, movement proteins, and to a much lesser extent, other viral proteins), RNAs [sense RNAs (translatable or not), antisense RNAs, satellite RNAs, defective-interfering RNAs, hairpin RNAs, and artificial microRNAs], nonviral genes (nucleases, antiviral inhibitors, and plantibodies), and host-derived resistance genes (dominant resistance genes and recessive resistance genes), and various factors involved in host defense responses. This review examines the above range of approaches used, the viruses that were tested, and the host species that have been examined for resistance, in many cases describing differences in results that were obtained for various systems developed in the last 20 years. We hope this compilation of experiences will aid those who are seeking to use this technology to provide resistance in yet other crops, where nature has not provided such. PMID:25410101

  6. Prediction of multi-locus inbreeding coefficients and relation to linkage disequilibrium in random mating populations.

    PubMed

    Hill, William G; Weir, Bruce S

    2007-09-01

    An algorithm to predict the level of identity by descent simultaneously at multiple loci is presented, which can in principle be extended to any number of loci. The model assumes a random mating population, with random association of haplotypes. The relationship is shown between coefficients of multi-locus identity or non-identity by descent and moments of multi-locus linkage disequilibrium. Thus, these moments can be computed from the multilocus identity or, using algorithms derived previously to predict the disequilibria moments, vice-versa. The results can be applied to predict multi-locus identity in, for example, gene mapping.

  7. 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

  8. A novel Drosophila Minute locus ribosomal protein S13

    SciTech Connect

    Saeboe-Larssen, S.; Lambertsson, A.

    1996-06-01

    Minutes comprise >50 phenotypically similar Drosophila mutations believed to affect ribosomal protein genes. Common traits of the Minute phenotype are short and thin bristles, slow development, and recessive lethality. To further investigate the proposed Minute to ribosomal protein correspondence, loss-of-function Minute mutations were induced by P-element mutagenesis. Here, we report a previously undescribed Minute locus that maps to 32A on chromosome 2L; this Minute allele is named P(lacW)M(2)32A{sup 1} and the gene M(2)32A. Flies heterozygous for P(lacW)M(2)32A{sup 1} have a medium Minute phenotype. The gene interrupted by the P-element insertion was cloned. Sequence analyses revealed that it encodes the Drosophila homologue of eukaryotic ribosomal protein S13. It is a single-copy gene and the level of RPS13 transcript is reduced to {approximately}50% in P(lacW)M(2)32A{sup 1} heterozygotes. Both transcript level and phenotype are restored to wild type by remobilizing the P element, demonstrating that the mutation is caused by insertion of the P-element construct. These results further strengthen the notion that Minutes encode ribosomal proteins and demonstrate the P-element mutagenesis is a fruitful approach to use in these studies. 47 refs., 7 figs.

  9. 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.

  10. Allelic interactions at the nivea locus of Antirrhinum.

    PubMed Central

    Bollmann, J; Carpenter, R; Coen, E S

    1991-01-01

    Most null alleles at the nivea (niv) locus are recessive to Niv+ and, when homozygous, give white flowers rather than the red of the wild type. In contrast, the niv-571 allele is semidominant; although it gives white flowers when homozygous, very pale flowers result when this allele is heterozygous with NIV+. We showed that in heterozygotes, niv-571 acts in trans to inhibit expression of its Niv+ homology 25-fold to 50-fold. The inhibition is reversible after meiosis and partially reversible somatically. The niv-571 allele carries a transposable element Tam3 insertion and three truncated copies of the niv gene, one copy being in inverse orientation. Analysis of two further niv alleles, niv-572 and niv-527, showed that excision of Tam3 from niv-571 does not affect the ability of the allele to repress Niv+ and that one truncated niv copy alone is insufficient to confer semidominance. The detailed structures of various semidominant niv alleles suggest that their effects in trans are not readily explained by production of antisense RNA but are more easily reconciled with a direct recognition/interaction between homologous genes, reminiscent of cosuppression and transvection phenomena described in other systems. PMID:1840900

  11. Mutations affecting expression of the rosy locus in Drosophila melanogaster

    SciTech Connect

    Lee, C.S.; Curtis, D.; McCarron, M.; Love, C.; Gray, M.; Bender, W.; Chovnick, A.

    1987-05-01

    The rosy locus in Drosophila melanogaster codes for the enzyme xanthine dehydrogenase (XDH). Previous studies defined a control element near the 5' end of the gene, where variant sites affected the amount of rosy mRNA and protein produced. The authors have determined the DNA sequence of this region from both genomic and cDNA clones, and from the ry/sup +10/ underproducer strain. This variant strain had many sequence differences, so that the site of the regulatory change could not be fixed. A mutagenesis was also undertaken to isolate new regulatory mutations. They induced 376 new mutations with 1-ethyl-1-nitrosourea (ENU) and screened them to isolate those that reduced the amount of XDH protein produced, but did not change the properties of the enzyme. Genetic mapping was used to find mutations located near the 5' end of the gene. DNA from each of seven mutants was cloned and sequenced through the 5' region. Mutant base changes were identified in all seven; they appear to affect splicing and translation of the rosy mRNA. In a related study, the genomic and cDNA sequences are extended through the 3' end of the gene; the combined sequences define the processing pattern of the rosy transcript and predict the amino acid sequence of XDH.

  12. The immunoglobulin light chain locus of the turkey, Meleagris gallopavo.

    PubMed

    Bao, Yonghua; Wu, Sun; Zang, Yunlong; Wang, Hui; Song, Xiangfeng; Xu, Chunyang; Xie, Bohong; Guo, Yongchen

    2012-06-15

    To date, most jawed vertebrate species encode more than one immunoglobulin light (IgL) chain isotypes. It has been shown that several bird species (chickens, white Pekin or domestic duck, and zebra finches) exclusively express lambda isotype. We analyze here the genomic organization of another bird species turkey IgL genes based on the recently released genome data. The turkey IgL locus located on chromosome 17 spans approximately 75.2kb and contains a single functional V(λ) gene, twenty V(λ) pseudogenes, and a single functional J(λ)-C(λ) block. These data suggest that the genomic organization of bird IgL chain genes seems to be conserved. Ten cDNA clones from turkey Igλ chain containing almost full-length V(λ), J(λ) and C(λ) segments were acquired. The comparison of V(λ) cDNA sequences to all the germline V(λ) segments suggests that turkey species may be generating IgL chain diversity by gene conversion and somatic hypermutation like the chicken. This study provides insights into the immunoglobulin light chain genes in another bird species.

  13. Comparative molecular population genetics of phycoerythrin locus in Prochlorococcus.

    PubMed

    Zhao, Fangqing; Qin, Song

    2007-03-01

    As the only remainder type of phycobiliproteins in Prochlorococcus, the actual role of phycoerythrin still remains unknown. Previous studies revealed that two different forms of phycoerythrin gene were found in two ecotypes of Prochlorococcus that are specifically adapted to either high light (HL) or low light (LL) conditions. Here we analyze patterns of phycoerythrin nucleotide variation in the HL- and LL-Prochlorococcus populations. Our analyses reveal a significantly greater number of non-synonymous fixed substitutions in peB and peA than expected based on interspecific comparisons. This pattern of excess non-synonymous fixed substitutions is not seen in other five phycoerythrin-related genes (peZ/V/Y/T/S). Several neutrality statistical tests indicate an excess of rare frequency polymorphisms in the LL-Prochlorococcus data, but an excess of intermediate frequency polymorphisms in the HL-Prochlorococcus data. Distributions of the positively selected sites identified using the likelihood ratio test, when mapped onto the phycoerythrin tertiary structure, reveal that HL- and LL-phycoerythrin should be under different selective patterns. These findings may provide insights into the likely role of selection at the phycoerythrin locus and motivate further research to unveil the function of phycoerythrin in Prochlorococcus. PMID:16897463

  14. 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

  15. Characterization of mutations at the mouse phenylalanine hydroxylase locus

    SciTech Connect

    McDonald, J.D.; Charlton, C.K.

    1997-02-01

    Two genetic mouse models for human phenylketonuria have been characterized by DNA sequence analysis. For each, a distinct mutation was identified within the protein coding sequence of the phenylalanine hydroxylase gene. This establishes that the mutated locus is the same as that causing human phenylketonuria and allows a comparison between these mouse phenylketonuria models and the human disease. A genotype/phenotype relationship that is strikingly similar to the human disease emerges, underscoring the similarity of phenylketonuria in mouse and man. In PAH{sup ENU1}, the phenotype is mild. The Pah{sup enu1} mutation predicts a conservative valine to alanine amino acid substitution and is located in exon 3, a gene region where serious mutations are rare in humans. In PAH{sup ENU2} the phenotype is severe. The Pah{sup enu2} mutation predicts a radical phenylalanine to serine substitution and is located in exon 7, a gene region where serious mutations are common in humans. In PAH{sup ENU2}, the sequence information was used to devise a direct genotyping system based on the creation of a new Alw26I restriction endonuclease site. 26 refs., 2 figs., 1 tab.

  16. 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

  17. The achromatic locus: effect of navigation direction in color space.

    PubMed

    Chauhan, Tushar; Perales, Esther; Xiao, Kaida; Hird, Emily; Karatzas, Dimosthenis; Wuerger, Sophie

    2014-01-24

    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.

  18. Association and heterogeneity at the GAPDH locus in Alzheimer's disease.

    PubMed

    Allen, Mariet; Cox, Claire; Belbin, Olivia; Ma, Li; Bisceglio, Gina D; Wilcox, Samantha L; Howell, Chanley C; Hunter, Talisha A; Culley, Oliver; Walker, Louise P; Carrasquillo, Minerva M; Dickson, Dennis W; Petersen, Ronald C; Graff-Radford, Neill R; Younkin, Steven G; Ertekin-Taner, Nilüfer

    2012-01-01

    Glyceraldehyde-3-phosphate dehydrogenase gene (GAPDH) and its paralogs were implicated in late-onset Alzheimer's disease (LOAD), although the strength and direction of association have not been consistent. We genotyped 3 previously reported single nucleotide polymorphisms (SNPs; rs3741916-GAPDH 5' UTR, rs2029721-pGAPD, and rs4806173-GAPDHS) in 3 case-control series (2112 cases and 3808 controls). Rs3741916 showed the strongest LOAD association (p = 0.003). The minor allele of rs3741916 showed a protective effect in our combined series (odds ratio [OR] = 0.87%, 95% confidence interval [CI] = 0.79-0.96). This is consistent with results from the 2 published follow-up studies and in opposite direction of the original report. Meta-analysis of the published series with ours suggests presence of heterogeneity (Breslow-Day p < 0.0001). Meta-analysis of only the follow-up series including ours revealed a significant protective effect for the minor allele of rs3741916 (OR = 0.85%, 95% CI = 0.76-0.96, p = 0.009). Our results support the presence of LOAD variants and heterogeneity at the GAPDH locus. The most promising rs3741916 variant is unlikely to be functional given opposing effects in different series. Identification of functional variant(s) in this region likely awaits deep sequencing.

  19. 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.

  20. Managing Resistance.

    ERIC Educational Resources Information Center

    Maag, John W.

    2000-01-01

    This article presents some considerations and ideas for managing students' resistance. They are organized around four topics: the impact of context on behavior, the importance of being comprehensive and nonrestrictive in behavior, the adaptive function of resistant behavior, and the benefit of joining children in their frame of reference.…

  1. STAT5A/B Gene Locus Undergoes Amplification during Human Prostate Cancer Progression

    PubMed Central

    Haddad, Bassem R.; Gu, Lei; Mirtti, Tuomas; Dagvadorj, Ayush; Vogiatzi, Paraskevi; Hoang, David T.; Bajaj, Renu; Leiby, Benjamin; Ellsworth, Elyse; Blackmon, Shauna; Ruiz, Christian; Curtis, Mark; Fortina, Paolo; Ertel, Adam; Liu, Chengbao; Rui, Hallgeir; Visakorpi, Tapio; Bubendorf, Lukas; Lallas, Costas D.; Trabulsi, Edouard J.; McCue, Peter; Gomella, Leonard; Nevalainen, Marja T.

    2014-01-01

    The molecular mechanisms underlying progression of prostate cancer (PCa) to castrate-resistant (CR) and metastatic disease are poorly understood. Our previous mechanistic work shows that inhibition of transcription factor Stat5 by multiple alternative methods induces extensive rapid apoptotic death of Stat5-positive PCa cells in vitro and inhibits PCa xenograft tumor growth in nude mice. Furthermore, STAT5A/B induces invasive behavior of PCa cells in vitro and in vivo, suggesting involvement of STAT5A/B in PCa progression. Nuclear STAT5A/B protein levels are increased in high-grade PCas, CR PCas, and distant metastases, and high nuclear STAT5A/B expression predicts early disease recurrence and PCa-specific death in clinical PCas. Based on these findings, STAT5A/B represents a therapeutic target protein for advanced PCa. The mechanisms underlying increased Stat5 protein levels in PCa are unclear. Herein, we demonstrate amplification at the STAT5A/B gene locus in a significant fraction of clinical PCa specimens. STAT5A/B gene amplification was more frequently found in PCas of high histologic grades and in CR distant metastases. Quantitative in situ analysis revealed that STAT5A/B gene amplification was associated with increased STAT5A/B protein expression in PCa. Functional studies showed that increased STAT5A/B copy numbers conferred growth advantage in PCa cells in vitro and as xenograft tumors in vivo. The work presented herein provides the first evidence of somatic STAT5A/B gene amplification in clinical PCas. PMID:23660011

  2. STAT5A/B gene locus undergoes amplification during human prostate cancer progression.

    PubMed

    Haddad, Bassem R; Gu, Lei; Mirtti, Tuomas; Dagvadorj, Ayush; Vogiatzi, Paraskevi; Hoang, David T; Bajaj, Renu; Leiby, Benjamin; Ellsworth, Elyse; Blackmon, Shauna; Ruiz, Christian; Curtis, Mark; Fortina, Paolo; Ertel, Adam; Liu, Chengbao; Rui, Hallgeir; Visakorpi, Tapio; Bubendorf, Lukas; Lallas, Costas D; Trabulsi, Edouard J; McCue, Peter; Gomella, Leonard; Nevalainen, Marja T

    2013-06-01

    The molecular mechanisms underlying progression of prostate cancer (PCa) to castrate-resistant (CR) and metastatic disease are poorly understood. Our previous mechanistic work shows that inhibition of transcription factor Stat5 by multiple alternative methods induces extensive rapid apoptotic death of Stat5-positive PCa cells in vitro and inhibits PCa xenograft tumor growth in nude mice. Furthermore, STAT5A/B induces invasive behavior of PCa cells in vitro and in vivo, suggesting involvement of STAT5A/B in PCa progression. Nuclear STAT5A/B protein levels are increased in high-grade PCas, CR PCas, and distant metastases, and high nuclear STAT5A/B expression predicts early disease recurrence and PCa-specific death in clinical PCas. Based on these findings, STAT5A/B represents a therapeutic target protein for advanced PCa. The mechanisms underlying increased Stat5 protein levels in PCa are unclear. Herein, we demonstrate amplification at the STAT5A/B gene locus in a significant fraction of clinical PCa specimens. STAT5A/B gene amplification was more frequently found in PCas of high histologic grades and in CR distant metastases. Quantitative in situ analysis revealed that STAT5A/B gene amplification was associated with increased STAT5A/B protein expression in PCa. Functional studies showed that increased STAT5A/B copy numbers conferred growth advantage in PCa cells in vitro and as xenograft tumors in vivo. The work presented herein provides the first evidence of somatic STAT5A/B gene amplification in clinical PCas.

  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. 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.

  5. The Measurement of Locus of Control in Black Preschool and Primary School Children.

    ERIC Educational Resources Information Center

    Duke, Marshall; Lewis, Gayle

    1979-01-01

    A form of the Preschool and Primary Nowicki-Strickland Locus of Control Scale was developed for use with Black children. The psychometric data suggest that the new scale is worthy of further examination and development. (Author/GDC)

  6. A new HaeIII polymorphism at the D21S13 locus.

    PubMed

    Pulst, S M; Korenberg, J R; Ren, M; Greenwald, J

    1990-10-01

    DNA markers in the pericentromeric region of human chromosome 21 have shown linkage to a gene for Familial Alzheimer disease (FAD; St. George Hyslop et al. 1987). The limited informativeness of probes for the loci D21S13 and D21S16 have hindered precise mapping of the FAD locus and analysis of non-allelic heterogeneity in FAD (Schellenberg et al. 1988; St. George-Hyslop et al. 1987). We recently described a new EcoRII polymorphism at the D21S13 locus that was very informative in a large FAD pedigree (Pulst et al. 1990a,b). We now report another polymorphism for the D21S13 locus that further increases the informativeness of this locus.

  7. Multidimensional Scales for the Measurement of Locus of Control of Reinforcements for Physical Fitness Behaviors.

    ERIC Educational Resources Information Center

    Whitehead, James R.; Corbin, Charles B.

    1988-01-01

    Trial administrations of the FITLOC, multidimensional scales for the measurement of locus of control of reinforcement for physical fitness behavior, provided preliminary evidence for the scales' reliability and validity. (Author/CB)

  8. Effects of Locus of Control and Type of Reinforcement on Programmed Instruction Performance of Adolescent Boys

    ERIC Educational Resources Information Center

    Gregory, Mary K.

    1976-01-01

    Students with an internal locus of control functioned well under a variety of conditions while students needing extrinsic reinforcement functioned well only when feedback was provided by the experimenter. (MM)

  9. The Ink4/Arf locus is a barrier for iPS reprogramming

    PubMed Central

    Li, Han; Collado, Manuel; Villasante, Aranzazu; Strati, Katerina; Ortega, Sagrario; Cañamero, Marta; Blasco, Maria A.; Serrano, Manuel

    2013-01-01

    The mechanisms involved in the reprogramming of differentiated cells into induced Pluripotent Stem (iPS) cells by Oct4, Klf4 and Sox2 (3F) remain poorly understood 1. The Ink4/Arf tumour suppressor locus encodes three potent inhibitors of proliferation, namely p16Ink4a, p15Ink4b and Arf, which are basally expressed in differentiated cells and upregulated by aberrant mitogenic signals 2-4. We show here that the locus is completely silenced in iPS cells, as well as in embryonic stem (ES) cells, acquiring the epigenetic marks of a bivalent chromatin domain, and retaining the ability to be reactivated upon differentiation. Cell culture conditions during reprogramming enhance the expression of the Ink4/Arf locus, further highlighting the importance of silencing the locus to allow proliferation and reprogramming. Indeed, the 3F together repress the Ink4/Arf locus soon after their expression and concomitant with the appearance of the first molecular markers of stemness. This downregulation also occurs in cells carrying the oncoprotein large-T, which functionally inactivates the pathways regulated by the Ink4/Arf locus, thus implying that the silencing of the locus is intrinsic to reprogramming and not the result of a selective process. Genetic inhibition of the Ink4/Arf locus has a profound positive impact on the efficiency of iPS generation, increasing both the kinetics of reprogramming and the number of emerging iPS colonies. In murine cells, Arf, rather than Ink4a, is the main barrier to reprogramming through activation of p53 and p21; whereas, in human fibroblasts, INK4a is more important than ARF. Finally, organismal aging upregulates the Ink4/Arf locus 2,5 and, accordingly, reprogramming is less efficient in cells from old organisms, but this defect can be rescued by inhibiting the locus with an shRNA. All together, we conclude that the silencing of Ink4/Arf locus is rate limiting for reprogramming, and its transient inhibition may significantly improve the

  10. Biofeedback and meditation: effects on muscle tension and locus of control.

    PubMed

    Zaichkowsky, L D; Kamen, R

    1978-06-01

    A total of 48 subjects participated in a relaxation experiment to determine whether frontalis muscle EMG biofeedback, Transcendental Meditation, and meditation (Benson technique) produced decreased muscle tension and concomitant changes in locus of control. All three treatments resulted in significant decreases in frontalis muscle tension when compared to a control. Concomitant changes towards an internal locus of control occurred only in the subjects given biofeedback.

  11. 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

  12. 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

  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. [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.

  15. [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

  16. Genetic relationship between lodging and lodging components in barley (Hordeum vulgare) based on unconditional and conditional quantitative trait locus analyses.

    PubMed

    Chen, W Y; Liu, Z M; Deng, G B; Pan, Z F; Liang, J J; Zeng, X Q; Tashi, N M; Long, H; Yu, M Q

    2014-03-17

    Lodging (LD) is a major constraint limiting the yield and forage quality of barley. Detailed analyses of LD component (LDC) traits were conducted using 246 F2 plants generated from a cross between cultivars ZQ320 and 1277. Genetic relationships between LD and LDC were evaluated by unconditional and conditional quantitative trait locus (QTL) mapping with 117 simple sequence repeat markers. Ultimately, 53 unconditional QTL related to LD were identified on seven barley chromosomes. Up to 15 QTL accounted for over 10% of the phenotypic variation, and up to 20 QTL for culm strength were detected. Six QTL with pleiotropic effects showing significant negative correlations with LD were found between markers Bmag353 and GBM1482 on chromosome 4H. These alleles and alleles of QTL for wall thickness, culm strength, plant height, and plant weight originated from ZQ320. Conditional mapping identified 96 additional QTL for LD. Conditional QTL analysis demonstrated that plant height, plant height center of gravity, and length of the sixth internode had the greatest contribution to LD, whereas culm strength and length of the fourth internode, and culm strength of the second internode were the key factors for LD-resistant. Therefore, lodging resistance in barley can be improved based on selection of alleles affecting culm strength, wall thickness, plant height, and plant weight. The conditional QTL mapping method can be used to evaluate possible genetic relationships between LD and LDC while efficiently and precisely determining counteracting QTL, which will help in understanding the genetic basis of LD in barley.

  17. High polymorphism at the human melanocortin 1 receptor locus.

    PubMed Central

    Rana, B K; Hewett-Emmett, D; Jin, L; Chang, B H; Sambuughin, N; Lin, M; Watkins, S; Bamshad, M; Jorde, L B; Ramsay, M; Jenkins, T; Li, W H

    1999-01-01

    Variation in human skin/hair pigmentation is due to varied amounts of eumelanin (brown/black melanins) and phaeomelanin (red/yellow melanins) produced by the melanocytes. The melanocortin 1 receptor (MC1R) is a regulator of eu- and phaeomelanin production in the melanocytes, and MC1R mutations causing coat color changes are known in many mammals. We have sequenced the MC1R gene in 121 individuals sampled from world populations with an emphasis on Asian populations. We found variation at five nonsynonymous sites (resulting in the variants Arg67Gln, Asp84Glu, Val92Met, Arg151Cys, and Arg163Gln), but at only one synonymous site (A942G). Interestingly, the human consensus protein sequence is observed in all 25 African individuals studied, but at lower frequencies in the other populations examined, especially in East and Southeast Asians. The Arg163Gln variant is absent in the Africans studied, almost absent in Europeans, and at a low frequency (7%) in Indians, but is at an exceptionally high frequency (70%) in East and Southeast Asians. The MC1R gene in common and pygmy chimpanzees, gorilla, orangutan, and baboon was sequenced to study the evolution of MC1R. The ancestral human MC1R sequence is identical to the human consensus protein sequence, while MC1R varies considerably among higher primates. A comparison of the rates of substitution in genes in the melanocortin receptor family indicates that MC1R has evolved the fastest. In addition, the nucleotide diversity at the MC1R locus is shown to be several times higher than the average nucleotide diversity in human populations, possibly due to diversifying selection. PMID:10101176

  18. Optimum mating systems for the myostatin locus in cattle.

    PubMed

    Keele, J W; Fahrenkrug, S C

    2001-08-01

    Inactive myostatin (one or two copies) results in increased muscularity, increased yield of closely trimmed retail product, reduced fat content, increased lean growth efficiency, reduced quality grade, increased birth weight, and increased dystocia. Even though one or two copies of inactive myostatin reduces quality grade or marbling compared to zero copies, there is no decrease in meat tenderness. It may be possible to use mating systems to make the most of the advantages of inactive myostatin while minimizing the disadvantages. The objective of this study was to develop a method to compare mating systems among genotypes at the myostatin locus. Economic variables that influence the profitability of alternative mating systems are prices per unit of retail product for USDA quality grades Standard, Select, and Choice; cost of an assisted calving; and cost of genotyping. Because of variation in both economic variables and biological parameters, a single mating system is not expected to universally maximize profit. We identified seven mating systems that each yield maximum profit for different combinations of values for biological parameters and economic variables. Use of inactive myostatin was profitable as long as the price for Select was at least 80% of the Choice price and the price for Standard at least 60%. As the price for Select and Standard increase up to the Choice price, mating systems that produce a higher proportion of inactive myostatin alleles become more profitable. Profitable use of inactive myostatin depends either on retaining ownership of beef until it is fabricated into retail product or the development of specialty markets that place greater value on lean yield and less on marbling, unlike conventional U. S. markets.

  19. The Lbw2 locus promotes autoimmune hemolytic anemia.

    PubMed

    Scatizzi, John C; Haraldsson, Maria K; Pollard, K Michael; Theofilopoulos, Argyrios N; Kono, Dwight H

    2012-04-01

    The lupus-prone New Zealand Black (NZB) strain uniquely develops a genetically imposed severe spontaneous autoimmune hemolytic anemia (AIHA) that is very similar to the corresponding human disease. Previous studies have mapped anti-erythrocyte Ab (AEA)-promoting NZB loci to several chromosomal locations, including chromosome 4; however, none of these have been analyzed with interval congenics. In this study, we used NZB.NZW-Lbw2 congenic (designated Lbw2 congenic) mice containing an introgressed fragment of New Zealand White (NZW) on chromosome 4 encompassing Lbw2, a locus previously linked to survival, glomerulonephritis, and splenomegaly, to investigate its role in AIHA. Lbw2 congenic mice exhibited marked reductions in AEAs and splenomegaly but not in anti-nuclear Abs. Furthermore, Lbw2 congenics had greater numbers of marginal zone B cells and reduced expansion of peritoneal cells, particularly the B-1a cell subset at early ages, but no reduction in B cell response to LPS. Analysis of a panel of subinterval congenic mice showed that the full effect of Lbw2 on AEA production was dependent on three subloci, with splenomegaly mapping to two of the subloci and expansions of peritoneal cell populations, including B-1a cells to one. These results directly demonstrated the presence of AEA-specific promoting genes on NZB chromosome 4, documented a marked influence of background genes on autoimmune phenotypes related to Lbw2, and further refined the locations of the underlying genetic variants. Delineation of the Lbw2 genes should yield new insights into both the pathogenesis of AIHA and the nature of epistatic interactions of lupus-modifying genetic variants.

  20. Role of TRAV Locus in Low Caries Experience

    PubMed Central

    Briseño-Ruiz, Jessica; Shimizu, Takehiko; Deeley, Kathleen; Dizak, Piper M.; Ruff, Timothy D.; Faraco, Italo M.; Poletta, Fernando A.; Brancher, João A.; Pecharki, Giovana D.; Küchler, Erika C.; Tannure, Patricia N.; Lips, Andrea; Vieira, Thays C.S.; Patir, Asli; Koruyucu, Mine; Mereb, Juan C.; Resick, Judith M.; Brandon, Carla A.; Letra, Ariadne; Silva, Renato M.; Cooper, Margaret E.; Seymen, Figen; Costa, Marcelo C.; Granjeiro, José M.; Trevilatto, Paula C.; Orioli, Iêda M.; Castilla, Eduardo E.; Marazita, Mary L.; Vieira, Alexandre R.

    2013-01-01

    Caries is the most common chronic, multifactorial disease in the world today; and little is still known about the genetic factors influencing susceptibility. Our previous genome- wide linkage scan has identified five loci related to caries susceptibility: 5q13.3, 13q31.1, 14q11.2, 14q 24.3, and Xq27. In the present study, we fine mapped the 14q11.2 locus in order to identify genetic contributors to caries susceptibility. Four hundred seventy-seven subjects from 72 pedigrees with similar cultural and behavioral habits and limited access to dental care living in the Philippines were studied. An additional 387 DNA samples from unrelated individuals were used to determine allele frequencies. For replication purposes, a total of 1,446 independent subjects from four different populations were analyzed based on their caries experience (low versus high). Forty-eight markers in 14q11.2 were genotyped using TaqMan chemistry. Transmission disequilibrium test was used to detect overtransmission of alleles in the Filipino families, and chi-square, Fisher’s exact and logistic regression were used to test for association between low caries experience and variant alleles in the replication data sets. We finally assessed the mRNA expression of TRAV4 in the saliva of 143 study subjects. In the Filipino families, statistically significant associations were found between low caries experience and markers in TRAV4. We were able to replicate these results in the populations studied that were characteristically from underserved areas. Direct sequencing of 22 subjects carrying the associated alleles detect one missense mutation (Y30R) that is predicted to be probably damaging. Finally, we observed higher expression in children and teenagers with low caries experience, correlating with specific alleles in TRAV4. Our results suggest TRAV4 may have a role in protecting against caries. PMID:23657505

  1. Evidence for meiotic drive at the myotonic dystrophy locus

    SciTech Connect

    Shaw, A.M.; Barnetson, R.A.; Phillips, M.F.

    1994-09-01

    Myotonic dystrophy (DM), an autosomal dominant disorder, is the most common form of adult muscular dystrophy, affecting at least 1 in 8000 of the population. It is a multisystemic disorder, primarily characterized by myotonia, muscle wasting and cataract. The molecular basis of DM is an expanded CTG repeat located within the 3{prime} untranslated region of a putative serine-threonine protein kinase on chromosome 19q13.3. DM exhibits anticipation, that is, with successive generations there is increasing disease severity and earlier age of onset. This mechanism and the fact that the origin of the disease has been attributed to one or a small number of founder chromosomes suggests that, in time, DM should die out. Meiotic drive has been described as a way in which certain alleles are transmitted to succeeding generations in preference to others: preferential transmission of large CTG alleles may account for their continued existence in the gene pool. There is evidence that a CTG allele with > 19 repeats may gradually increase in repeat number over many generations until it is sufficiently large to give a DM phenotype. We report a study of 495 transmissions from individuals heterozygous for the CTG repeat and with repeat numbers within the normal range (5-30). Alleles were simply classified as large or small relative to the other allele in an individual. Of 242 male meioses, 126 transmissions from parent to child were of the larger allele to their offspring (57.7%, p=0.014). This shows that there is strong evidence for meiotic drive favoring the transmission of the larger DM allele in unaffected individuals. Contrary to a previous report of meiotic drive in the male, we have shown that females preferentially transmit the larger DM allele. Taken together, the data suggest the occurrence of meiotic drive in both males and females in this locus.

  2. 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

  3. 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…

  4. Locus of control and peer relationships among Caucasian, Hispanic, Asian, and African American adolescents.

    PubMed

    Kang, Hannah Soo; Chang, Kyle Edward; Chen, Chuansheng; Greenberger, Ellen

    2015-01-01

    Past research has shown that locus of control plays an important role in a wide range of behaviors, such as academic achievement and positive social behaviors. However, little is known about whether locus of control plays the same role in minority adolescents' peer relationships. The current study examined ethnic differences in the associations between locus of control and peer relationships in early adolescence using samples from the Early Childhood Longitudinal Study (ECLS-K: 5,612 Caucasian, 1,562 Hispanic, 507 Asian, and 908 African-American adolescents) and the National Education Longitudinal Study (NELS: 8,484 Caucasian, 1,604 Hispanic, and 860 Asian, and 1,228 African American adolescents). Gender was approximately evenly split in both samples. The results from the two datasets were highly consistent. Significant interactions between ethnicity and locus of control indicated that having a more internal locus of control was particularly important for Caucasian students' peer relationships (ECLS-K) and social status (NELS), but less so for Asian, Hispanic, and African American students. Our findings suggest that the role of locus of control in peer relationship is contingent upon culture. PMID:24352586

  5. Comparing health locus of control in patients with Spasmodic Dysphonia, Functional Dysphonia and Nonlaryngeal Dystonia.

    PubMed

    Haselden, Karen; Powell, Theresa; Drinnan, Mike; Carding, Paul

    2009-11-01

    Locus of Control (LoC) refers to an individuals' perception of whether they are in control of life events. Health Locus of Control refers to whether someone feels they have influence over their health. Health Locus of Control has not been studied in any depth in voice-disordered patients. The objective of this study was to examine Health Locus of Control in three patient groups: (1) Spasmodic Dysphonia, (2) Functional Dysphonia and (3) a nondysphonic group with Nonlaryngeal Dystonia. LoC was measured and compared in a total of 57 patients using the Multidimensional Health Locus of Control Scales (diagnostic specific) Form C. Internal, Chance, and Powerful others LoC were measured and comparisons were made using one-way analysis of variance. Contrary to expectations Internal LoC was found to be significantly higher in the Functional Dysphonia group when compared to the other two groups. There was no significant difference between the groups in Chance or Powerful others LoC. The two organic groups, Spasmodic Dysphonia and Nonlaryngeal Dystonia, were more alike in Internal Health Locus of Control than the Functional Dysphonia group. The diagnostic nature of the groups was reflected in their LoC scores rather than their voice loss. These results contribute to the debate about the etiology of Spasmodic Dysphonia and will be of interest to those involved in the psychology of voice and those managing voice-disordered patients.

  6. Intra-locus sexual conflict and sexually antagonistic genetic variation in hermaphroditic animals

    PubMed Central

    Abbott, Jessica K.

    2011-01-01

    Intra-locus sexual conflict results when sex-specific selection pressures for a given trait act against the intra-sexual genetic correlation for that trait. It has been found in a wide variety of taxa in both laboratory and natural populations, but the importance of intra-locus sexual conflict and sexually antagonistic genetic variation in hermaphroditic organisms has rarely been considered. This is not so surprising given the conceptual and theoretical association of intra-locus sexual conflict with sexual dimorphism, but there is no a priori reason why intra-locus sexual conflict cannot occur in hermaphroditic organisms as well. Here, I discuss the potential for intra-locus sexual conflict in hermaphroditic animals and review the available evidence for such conflict, and for the existence of sexually antagonistic genetic variation in hermaphrodites. I argue that mutations with asymmetric effects are particularly likely to be important in mediating sexual antagonism in hermaphroditic organisms. Moreover, sexually antagonistic genetic variation is likely to play an important role in inter-individual variation in sex allocation and in transitions to and from gonochorism (separate sexes) in simultaneous hermaphrodites. I also describe how sequential hermaphrodites may experience a unique form of intra-locus sexual conflict via antagonistic pleiotropy. Finally, I conclude with some suggestions for further research. PMID:20719776

  7. The stability of locus equation slopes across stop consonant voicing/aspiration

    NASA Astrophysics Data System (ADS)

    Sussman, Harvey M.; Modarresi, Golnaz

    2001-05-01

    The consistency of locus equation slopes as phonetic descriptors of stop place in CV sequences across voiced and voiceless aspirated stops was explored in the speech of five male speakers of American English and two male speakers of Persian. Using traditional locus equation measurement sites for F2 onsets, voiceless labial and coronal stops had significantly lower locus equation slopes relative to their voiced counterparts, whereas velars failed to show voicing differences. When locus equations were derived using F2 onsets for voiced stops that were measured closer to the stop release burst, comparable to the protocol for measuring voiceless aspirated stops, no significant effects of voicing/aspiration on locus equation slopes were observed. This methodological factor, rather than an underlying phonetic-based explanation, provides a reasonable account for the observed flatter locus equation slopes of voiceless labial and coronal stops relative to voiced cognates reported in previous studies [Molis et al., J. Acoust. Soc. Am. 95, 2925 (1994); O. Engstrand and B. Lindblom, PHONUM 4, 101-104]. [Work supported by NIH.

  8. Locus heterogeneity disease genes encode proteins with high interconnectivity in the human protein interaction network.

    PubMed

    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.

  9. A Novel Route Controlling Begomovirus Resistance by the Messenger RNA Surveillance Factor Pelota.

    PubMed

    Lapidot, Moshe; Karniel, Uri; Gelbart, Dana; Fogel, Doron; Evenor, Dalia; Kutsher, Yaarit; Makhbash, Zion; Nahon, Sahadia; Shlomo, Haviva; Chen, Lea; Reuveni, Moshe; Levin, Ilan

    2015-10-01

    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

  10. 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

  11. Resistivity analysis

    DOEpatents

    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.

  12. 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, ...

  13. 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 ...

  14. Recombinant Inbred Strain and Interspecific Backcross Analysis of Molecular Markers Flanking the Murine Agouti Coat Color Locus

    PubMed Central

    Siracusa, L. D.; Buchberg, A. M.; Copeland, N. G.; Jenkins, N. A.

    1989-01-01

    Recombinant inbred strain and interspecific backcross mice were used to create a molecular genetic linkage map of the distal portion of mouse chromosome 2. The orientation and distance of the Ada, Emv-13, Emv-15, Hck-1, Il-1a, Pck-1, Psp, Src-1 and Svp-1 loci from the β(2)-microglobulin locus and the agouti locus were established. Our mapping results have provided the identification of molecular markers both proximal and distal to the agouti locus. The recombinants obtained provide valuable resources for determining the direction of chromosome walking experiments designed to clone sequences at the agouti locus. Comparisons between the mouse and human genome maps suggest that the human homolog of the agouti locus resides on human chromosome 20q. Three loci not present on mouse chromosome 2 were also identified and were provisionally named Psp-2, Hck-2 and Hck-3. The Psp-2 locus maps to mouse chromosome 14. The Hck-2 locus maps near the centromere of mouse chromosome 4 and may identify the Lyn locus. The Hck-3 locus maps near the distal end of mouse chromosome 4 and may identify the Lck locus. PMID:2759422

  15. Identification, Validation, and Application of Molecular Diagnostics for Insecticide Resistance in Malaria Vectors.

    PubMed

    Donnelly, Martin J; Isaacs, Alison T; Weetman, David

    2016-03-01

    Insecticide resistance is a major obstacle to control of Anopheles malaria mosquitoes in sub-Saharan Africa and requires an improved understanding of the underlying mechanisms. Efforts to discover resistance genes and DNA markers have been dominated by candidate gene and quantitative trait locus studies of laboratory strains, but with greater availability of genome sequences a shift toward field-based agnostic discovery is anticipated. Mechanisms evolve continually to produce elevated resistance yielding multiplicative diagnostic markers, co-screening of which can give high predictive value. With a shift toward prospective analyses, identification and screening of resistance marker panels will boost monitoring and programmatic decision making.

  16. Identification, Validation, and Application of Molecular Diagnostics for Insecticide Resistance in Malaria Vectors.

    PubMed

    Donnelly, Martin J; Isaacs, Alison T; Weetman, David

    2016-03-01

    Insecticide resistance is a major obstacle to control of Anopheles malaria mosquitoes in sub-Saharan Africa and requires an improved understanding of the underlying mechanisms. Efforts to discover resistance genes and DNA markers have been dominated by candidate gene and quantitative trait locus studies of laboratory strains, but with greater availability of genome sequences a shift toward field-based agnostic discovery is anticipated. Mechanisms evolve continually to produce elevated resistance yielding multiplicative diagnostic markers, co-screening of which can give high predictive value. With a shift toward prospective analyses, identification and screening of resistance marker panels will boost monitoring and programmatic decision making. PMID:26750864

  17. 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

  18. 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

  19. Molecular mapping of QTLs for Fusarium head blight resistance in spring wheat. I. Resistance to fungal spread (Type II resistance).

    PubMed

    Buerstmayr, H; Lemmens, M; Hartl, L; Doldi, L; Steiner, B; Stierschneider, M; Ruckenbauer, P

    2002-01-01

    Fusarium head blight (FHB, scab) is a fungal disease of wheat and other small cereals that is found in both temperate and semi-tropical regions. FHB causes severe yield and quality losses, but the most-serious concern is the possible mycotoxin contamination of cereal food and feed. Breeding for FHB resistance by conventional selection is feasible, but tedious and expensive. This study was conducted to identify and map DNA markers associated with FHB resistance genes in wheat. A population of 364 F(1)-derived doubled-haploid (DH) lines from the cross 'CM-82036' (resistant)/'Remus' (susceptible) was evaluated for Type II resistance (spread within the spike) during 2 years under field conditions. Marker analysis was performed on 239 randomly chosen DH lines. Different marker types were applied, with an emphasis on AFLP and SSR markers. Analysis of variance, as well as simple and composite interval mapping, were applied. Three genomic regions were found significantly associated with FHB resistance. The most-prominent effect was detected on the short arm of chromosome 3B, explaining up to 60% of the phenotypic variance for Type II FHB resistance. A further QTL was located on chromosome 5A and a third one on 1B. The QTL regions on 3B and 5A were tagged with flanking SSR markers, the 1B QTL was found associated with the high-molecular-weight glutenin locus. These results indicate that FHB resistance is under control of a few major QTLs operating together with unknown numbers of minor genes. Marker-assisted selection for these major QTLs involved in FHB resistance appears feasible and should accelerate the development of resistant and agronomically improved wheat cultivars.

  20. FGF12 is a candidate Brugada syndrome locus

    PubMed Central

    Hennessey, Jessica A.; Marcou, Cherisse A.; Wang, Chuan; Wei, Eric Q.; Wang, Chaojian; Tester, David J.; Torchio, Margherita; Dagradi, Federica; Crotti, Lia; Schwartz, Peter J.; Ackerman, Michael J.; Pitt, Geoffrey S.

    2013-01-01

    BACKGROUND Less than 30% of the cases of Brugada syndrome (BrS) have an identified genetic cause. Of the known BrS-susceptibility genes, loss-of-function mutations in SCN5A or CACNA1C and their auxiliary subunits are most common. On the basis of the recent demonstration that fibroblast growth factor (FGF) homologous factors (FHFs; FGF11–FGF14) regulate cardiac Na+ and Ca2+ channel currents, we hypothesized that FHFs are candidate BrS loci. OBJECTIVE The goal of this study was to test whether FGF12 is a candidate BrS locus. METHODS We used quantitative polymerase chain reaction to identify the major FHF expressed in the human ventricle and then queried a phenotype-positive, genotype-negative BrS biorepository for FHF mutations associated with BrS. We queried the effects of an identified mutant with biochemical analyses combined with electrophysiological assessment in a novel rat ventricular cardiomyocyte system in which we swapped the endogenous FHF with the identified mutant on multiple ionic currents in their native milieu and on the cardiac action potential. RESULTS We identified FGF12 as the major FHF expressed in the human ventricle. In 102 individuals in the biorepository, we identified a single missense mutation in FGF12-B (Q7R-FGF12). The mutant reduced binding to the NaV1.5 C terminus, but not to junctophilin-2, which mediates Ca2+ channel regulation. In rats, adult cardiac myocytes Q7R-FGF12, but not wild-type FGF12, reduced Na+ channel current density and availability without affecting Ca2+ channel function. Furthermore, the mutant, but not wild-type FGF12, reduced action potential amplitude, which is consistent with a mutant-induced loss of Na+ channel function. CONCLUSIONS These multilevel investigations strongly suggest that Q7R-FGF12 is a disease-associated BrS mutation. Moreover, these data suggest for the first time that FHF effects on Na+ and Ca2+ channels are separable. Most significantly, this study establishes a new method to analyze effects

  1. Health locus of control beliefs among school children.

    PubMed

    Fetohy, E M

    2001-01-01

    The purpose of the present study is to measure Children Health Locus of control (CHLC) beliefs among school children using the scale developed by Abdel-Gawwad et al. (1999) to test the differences of the beliefs by children's some sociodemographic characteristics and Body Mass Index (BMI). A cross sectional study design was applied using a stratified random sample of 1500 pupils from the final two grades of primary and all grades of the preparatory schools. The scale consisted of 25 statements with a 4-point Likert format. Body mass index was also calculated. From data analysis 15% of the pupils were obese. The mean score of internality increase with increasing age also powerful others' mean score increase with increasing age till the age of 11 - < 12 years and decrease again till the age14 - < 15 years. Chance's mean score decreases with increasing age till the age 14 - < 15 years. Self blame and fate subscales showed irregular decrease with increasing age. Girls had significantly higher mean score of fate subscale than boys (F = 10.67, p < 0.01). Boys had significantly higher mean score of total CHLC scale than girls (12.68, p < 0.01). Obese pupils had significantly higher mean scores of internality and total CHLC scale than non obese pupils (t = 2.58, 2.02, p < 0.05, respectively). Obese pupils had significantly lower mean scores of powerful others, chance and self blame (t = 2.09, 16.51, 2.00, p < 0.05, 0.01, 0.05, respectively). Total CHLC mean scores increased with increasing mother's education (F = 8.99, p < 0.01). Chance mean score decreased with increasing mother's education (F = 11.43, p < 0.01). Total CHLC mean scores increased with increasing father's education (F = 7.6, p < 0.01). Powerful others mean score decreased with increasing father's education (F = 4.42, p < 0.01). Pupils from private schools had higher mean scores of chance and total CHLC (t = 7.0, 7.26, p < 0.01, respectively). They also had lower powerful others and fate mean scores (t = 4

  2. Resistance of Mice of the 129 Background to Yersinia pestis Maps to Multiple Loci on Chromosome 1.

    PubMed

    Tencati, Michael; Tapping, Richard I

    2016-10-01

    Yersinia pestis is a Gram-negative bacterium that is the causative agent of bubonic and pneumonic plague. It is commonly acquired by mammals such as rodents and humans via the bite of an infected flea. We previously reported that multiple substrains of the 129 mouse background are resistant to pigmentation locus-negative (pgm(-)) Yersinia pestis and that this phenotype maps to a 30-centimorgan (cM) region located on chromosome 1. In this study, we have further delineated this plague resistance locus to a region of less than 20 cM through the creation and phenotyping of recombinant offspring arising from novel crossovers in this region. Furthermore, our experiments have revealed that there are at least two alleles in this initial locus, both of which are required for resistance on a susceptible C57BL/6 background. These two alleles work in trans since resistance is restored in offspring possessing one allele contributed by each parent. Our studies also indicated that the Slc11a1 gene (formerly known as Nramp1) located within the chromosome1 locus is not responsible for conferring resistance to 129 mice. PMID:27481241

  3. Growth interaction between locus coeruleus and trigeminal ganglion after intraocular double grafting.

    PubMed

    Seiger, A

    1980-06-01

    Fetal trigeminal ganglia were combined in the anterior chamber of eyes of rat recipients with sequentially grafted fetal locus coeruleus transplants. After maturation of both grafts in oculo the growth pattern of locus coeruleus derived noradrenaline fibres in the iris was examined with Falck-Hillarp fluorescence histochemistry. Contrary to what was expected from earlier studies, which revealed a radiating halo of fibres around the CNS tissue on the iris, the locus coeruleus-derived fibres radiated to a large extent from the adjacent trigeminal ganglion attachment. Thus, the presence of a grafted trigeminal ganglion changed the distribution of the central monoamine nerves growing out in the iris. The possible cause of this changed distribution is discussed. Maturated intraocular trigeminal ganglion transplants were retransplanted, together with the whole iris to which it was attached, into a new eye which already harboured a maturated locus coeruleus graft attached to its host iris. The expected reinitiated locus coeruleus fibre ingrowths into the iris transplants were then compared in those iris transplants that had trigeminal ganglia and controls that had not. The surface area of the iris grafts covered by newly formed locus coeruleus noradrenaline fibres was significantly smaller (27% reduction) if trigeminal ganglia were situated on them during the reinnervation process. This finding strongly supports our earlier studies, which suggested that the presence of sensory nerves in the iris inhibits growth of locus coeruleus in that receptor tissue, and furthermore, that the sensory nerves responsible for this inhibitory interaction have their origin within the trigeminal ganglion itself. PMID:7253725

  4. Distinct contracted conformations of the Tcra/Tcrd locus during Tcra and Tcrd recombination

    PubMed Central

    Shih, Han-Yu

    2010-01-01

    Studies have suggested that antigen receptor loci adopt contracted conformations to promote long-distance interactions between gene segments during V(D)J recombination. The Tcra/Tcrd locus is unique because it undergoes highly divergent Tcrd and Tcra recombination programs in CD4−CD8− double negative (DN) and CD4+CD8+ double positive (DP) thymocytes, respectively. Using three-dimensional fluorescence in situ hybridization, we asked whether these divergent recombination programs are supported by distinct conformational states of the Tcra/Tcrd locus. We found that the 3′ portion of the locus is contracted in DN and DP thymocytes but not in B cells. Remarkably, the 5′ portion of the locus is contracted in DN thymocytes but is decontracted in DP thymocytes. We propose that the fully contracted conformation in DN thymocytes allows Tcrd rearrangements involving Vδ gene segments distributed over 1 Mb, whereas the unique 3′-contracted, 5′-decontracted conformation in DP thymocytes biases initial Tcra rearrangements to the most 3′ of the available Vα gene segments. This would maintain a large pool of distal 5′ Vα gene segments for subsequent rounds of recombination. Thus, distinct contracted conformations of the Tcra/Tcrd locus may facilitate a transition from a Tcrd to a Tcra mode of recombination during thymocyte development. PMID:20696701

  5. Effects of recombination on hitchhiking diversity in the Brassica self-incompatibility locus complex.

    PubMed

    Takuno, Shohei; Fujimoto, Ryo; Sugimura, Tetsu; Sato, Keiichi; Okamoto, Shunsuke; Zhang, Shao-Ling; Nishio, Takeshi

    2007-10-01

    In self-incompatibility, a number of S haplotypes are maintained by frequency-dependent selection, which results in trans-specific S haplotypes. The region of several kilobases (approximately 40-60 kb) from SP6 to SP2, including self-incompatibility-related genes and some adjacent genes in Brassica rapa, has high nucleotide diversity due to the hitchhiking effect, and therefore we call this region the "S-locus complex." Recombination in the S-locus complex is considered to be suppressed. We sequenced regions of >50 kb of the S-locus complex of three S haplotypes in B. rapa and found higher nucleotide diversity in intergenic regions than in coding regions. Two highly similar regions of >10 kb were found between BrS-8 and BrS-46. Phylogenetic analysis using trans-specific S haplotypes (called interspecific pairs) of B. rapa and B. oleracea suggested that recombination reduced the nucleotide diversity in these two regions and that the genes not involved in self-incompatibility in the S-locus complex and the kinase domain, but not the S domain, of SRK have also experienced recombination. Recombination may reduce hitchhiking diversity in the S-locus complex, whereas the region from the S domain to SP11 would disfavor recombination.

  6. [Genetic study of the Penta E locus and identification of rare alleles].

    PubMed

    Lai, Li; Shen, Xiaoli; Han, Lili; Chen, Dian; Hu, Jie

    2015-10-01

    OBJECTIVE To study the genetic polymorphisms of Penta E locus in Fujian Han population. METHODS Polymorphisms of the Penta E locus in 851 unrelated individuals were analyzed using polymerase chain reaction-short tandem repeat (PCR-STR). The mutation rate of rare alleles was analyzed in 494 paternity identification cases (in a total of 674 meiosis). RESULTS Twenty-six alleles were identified for the Penta E locus, with their frequencies ranging from 0.0006 to 0.1528. There were 7 rare alleles, among which Penta E-28.4 ([AAAGA]29) was identified for the first time. Genetic parameters of the Penta E locus in Fujian Han population were obtained, including PIC= 0.91, PE= 0.817, PD= 0.986, and mutation rate= 0.0015. CONCLUSION The Penta E locus is highly polymorphic and has a low mutation rate in Fujian Han population. It also has a good prospect in genetics applications. DNA sequencing is a good method for identifying rare alleles. PMID:26418985

  7. Hybrid male sterility in rice is due to epistatic interactions with a pollen killer locus.

    PubMed

    Kubo, Takahiko; Yoshimura, Atsushi; Kurata, Nori

    2011-11-01

    In intraspecific crosses between cultivated rice (Oryza sativa) subspecies indica and japonica, the hybrid male sterility gene S24 causes the selective abortion of male gametes carrying the japonica allele (S24-j) via an allelic interaction in the heterozygous hybrids. In this study, we first examined whether male sterility is due solely to the single locus S24. An analysis of near-isogenic lines (NIL-F(1)) showed different phenotypes for S24 in different genetic backgrounds. The S24 heterozygote with the japonica genetic background showed male semisterility, but no sterility was found in heterozygotes with the indica background. This result indicates that S24 is regulated epistatically. A QTL analysis of a BC(2)F(1) population revealed a novel sterility locus that interacts with S24 and is found on rice chromosome 2. The locus was named Epistatic Factor for S24 (EFS). Further genetic analyses revealed that S24 causes male sterility when in combination with the homozygous japonica EFS allele (efs-j). The results suggest that efs-j is a recessive sporophytic allele, while the indica allele (EFS-i) can dominantly counteract the pollen sterility caused by S24 heterozygosity. In summary, our results demonstrate that an additional epistatic locus is an essential element in the hybrid sterility caused by allelic interaction at a single locus in rice. This finding provides a significant contribution to our understanding of the complex molecular mechanisms underlying hybrid sterility and microsporogenesis.

  8. Genetic instability in Drosophila melanogaster: evidence for regulation, excision and transposition at the white locus.

    PubMed

    Rasmuson, B; Montell, I; Rasmuson, A; Svahlin, H; Westerberg, B M

    1980-01-01

    An unstable long tandem duplication which includes the white locus twice, marked with wsp in the left and w17g in the right locus, when kept in males has been found to produce red-eyed sons which have lost the long duplication and with it the wsp and w17g mutants. Such exceptions were produced also when w17g had been exchanged for wa. Stocks originating from these exceptions are unstable, producing: 1) zeste males, also unstable, 2) w- deletions, stable, 3) transpositions of the white locus to sites in other chromosomes. The instability is interpreted as the effect of an IS element, within or adjacent to the white locus, which is supposed to retain a duplication of the proximal zeste interacting part of this locus. According to the orientation of the IS element the duplicated part can be active or inactive, giving a zeste or red eye phenotype. The frequency of exceptional offspring after X-ray treatment of the red and zeste unstable stocks have been compared to stable stocks with corresponding genotypes. PMID:6247608

  9. Construction, complete sequence, and annotation of a BAC contig covering the silkworm chorion locus

    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

    The silkmoth chorion was studied extensively by F.C. Kafatos’ group for almost 40 years. However, the complete structure of the chorion locus was not obtained in the genome sequence of Bombyx mori published in 2008 due to repetitive sequences, resulting in gaps and an incomplete view of the locus. To obtain the complete sequence of the chorion locus, expressed sequence tags (ESTs) derived from follicular epithelium cells were used as probes to screen a bacterial artificial chromosome (BAC) library. Seven BACs were selected to construct a contig which covered the whole chorion locus. By Sanger sequencing, we successfully obtained complete sequences of the chorion locus spanning 871,711 base pairs on chromosome 2, where we annotated 127 chorion genes. The dataset reported here will recruit more researchers to revisit one of the oldest model systems which has been used to study developmentally regulated gene expression. It also provides insights into egg development and fertilization mechanisms and is relevant to applications related to improvements in breeding procedures and transgenesis. PMID:26594380

  10. Molecular cloning of the white locus region of Drosophila melanogaster using a large transposable element

    PubMed Central

    Goldberg, M.L.; Paro, R.; Gehring, W.J.

    1982-01-01

    We report the molecular cloning of a chromosome segment including the white locus of Drosophila melanogaster. This region was isolated using a deficiency extending from the previously cloned heat-shock puff sequences at 87A7 to a large transposable element containing the loci white and roughest.FB-NOF, a 7.5 kb element with partial homology to a family of inverted repeat sequences (Potter et al., 1980), is found very near the deficiency breakpoint, and is followed by DNA originating from the white locus region. Sequences totalling ˜60 kb surrounding this initial entry point were obtained by the cloning of successively overlapping fragments from a wild-type strain. Several rearrangement breakpoints have been mapped relative to the cloned DNA; these define the limits of the white locus and further differentiate the “white proximal region”, thought to function in gene regulation, from the remainder of the locus. Insertion of the dispersed repetitive element copia into the white locus is observed in strains carrying the white-apricot allele. Analysis of several white-apricot revertants suggests that copia insertion is responsible for the apricot eye color phenotype. ImagesFig. 2.Fig. 4.Fig. 5.Fig. 6. PMID:16453411

  11. Construction, complete sequence, and annotation of a BAC contig covering the silkworm chorion locus.

    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

    The silkmoth chorion was studied extensively by F.C. Kafatos' group for almost 40 years. However, the complete structure of the chorion locus was not obtained in the genome sequence of Bombyx mori published in 2008 due to repetitive sequences, resulting in gaps and an incomplete view of the locus. To obtain the complete sequence of the chorion locus, expressed sequence tags (ESTs) derived from follicular epithelium cells were used as probes to screen a bacterial artificial chromosome (BAC) library. Seven BACs were selected to construct a contig which covered the whole chorion locus. By Sanger sequencing, we successfully obtained complete sequences of the chorion locus spanning 871,711 base pairs on chromosome 2, where we annotated 127 chorion genes. The dataset reported here will recruit more researchers to revisit one of the oldest model systems which has been used to study developmentally regulated gene expression. It also provides insights into egg development and fertilization mechanisms and is relevant to applications related to improvements in breeding procedures and transgenesis. PMID:26594380

  12. HLA-B locus polymorphism: studies with a specific hybridization probe.

    PubMed Central

    Coppin, H L; Denny, D W; Weissman, S M; McDevitt, H O

    1985-01-01

    The large number of class I histocompatibility genes (HLA) and their extensive homology has made it difficult to assign bands on genomic Southern blots to known genes. Therefore, we have tried to obtain nucleic acid probes for class I genes that are locus specific or have restricted locus specificity. Computer sequence-homology analysis was used to compare the nucleic acid sequences of two genomic clones, one coding for the HLA-B7 antigen (JY150) and one containing a class I pseudogene (pHLA12.4). A sequence in the 3' untranslated region with very low homology was identified. This sequence from the HLA-B7 gene was subcloned into M13 phage. This fragment, JY150/C5, hybridized with two genomic bands in DNA from human HLA homozygotes--presumably the HLA-B locus gene and a closely related gene. The probe was used to assess restriction fragment polymorphism at the HLA-B locus in homozygous consanguineous cell lines. This analysis permitted the association of certain polymorphic restriction enzyme fragments with some alleles of this locus. However, many HLA-B alleles have identical restriction fragments produced by a number of restriction endonucleases. Images PMID:3001712

  13. Analysis of meiotic segregation, using single-sperm typing: Meiotic drive at the myotonic dystrophy locus

    SciTech Connect

    Leeflang, E.P.; Arnheim, N.; McPeek, M.S.

    1996-10-01

    Meiotic drive at the myotonic dystrophy (DM) locus has recently been suggested as being responsible for maintaining the frequency, in the human population, of DM chromosomes capable of expansion to the disease state. In order to test this hypothesis, we have studied samples of single sperm from three individuals heterozygous at the DM locus, each with one allele larger and one allele smaller than 19 CTG repeats. To guard against the possible problem of differential PCR amplification rates based on the lengths of the alleles, the sperm were also typed at another closely linked marker whose allele size was unrelated to the allele size at the DM locus. Using statistical models specifically designed to study single-sperm segregation data, we find no evidence of meiotic segregation distortion. The upper limit of the two-sided 95% confidence interval for the estimate of the common segregation probability for the three donors is at or below .515 for all models considered, and no statistically significant difference from .5 is detected in any of the models. This suggests that any greater amount of segregation distortion at the myotonic dystrophy locus must result from events following sperm ejaculation. The mathematical models developed make it possible to study segregation distortion with high resolution by using sperm-typing data from any locus. 26 refs., 1 fig., 8 tabs.

  14. The IgH locus 3' regulatory region: pulling the strings from behind.

    PubMed

    Pinaud, Eric; Marquet, Marie; Fiancette, Rémi; Péron, Sophie; Vincent-Fabert, Christelle; Denizot, Yves; Cogné, Michel

    2011-01-01

    Antigen receptor gene loci are among the most complex in mammals. The IgH locus, encoding the immunoglobulin heavy chain (IgH) in B-lineage cells, undergoes major transcription-dependent DNA remodeling events, namely V(D)J recombination, Ig class-switch recombination (CSR), and somatic hypermutation (SHM). Various cis-regulatory elements (encompassing promoters, enhancers, and chromatin insulators) recruit multiple nuclear factors in order to ensure IgH locus regulation by tightly orchestrated physical and/or functional interactions. Among major IgH cis-acting regions, the large 3' regulatory region (3'RR) located at the 3' boundary of the locus includes several enhancers and harbors an intriguing quasi-palindromic structure. In this review, we report progress insights made over the past decade in order to describe in more details the structure and functions of IgH 3'RRs in mouse and human. Generation of multiple cellular, transgenic and knock-out models helped out to decipher the function of the IgH 3' regulatory elements in the context of normal and pathologic B cells. Beside its interest in physiology, the challenge of elucidating the locus-wide cross talk between distant cis-regulatory elements might provide useful insights into the mechanisms that mediate oncogene deregulation after chromosomal translocations onto the IgH locus.

  15. Meiotic drive influences the outcome of sexually antagonistic selection at a linked locus.

    PubMed

    Patten, M M

    2014-11-01

    Most meiotic drivers, such as the t-haplotype in Mus and the segregation distorter (SD) in Drosophila, act in a sex-specific manner, gaining a transmission advantage through one sex although suffering only the fitness costs associated with the driver in the other. Their inheritance is thus more likely through one of the two sexes, a property they share with sexually antagonistic alleles. Previous theory has shown that pairs of linked loci segregating for sexually antagonistic alleles are more likely to remain polymorphic and that linkage disequilibrium accrues between them. I probe this similarity between drive and sexual antagonism and examine the evolution of chromosomes experiencing these selection pressures simultaneously. Reminiscent of previous theory, I find that: the opportunity for polymorphism increases for a sexually antagonistic locus that is physically linked to a driving locus; the opportunity for polymorphism at a driving locus also increases when linked to a sexually antagonistic locus; and stable linkage disequilibrium accompanies any polymorphic equilibrium. Additionally, I find that drive at a linked locus favours the fixation of sexually antagonistic alleles that benefit the sex in which drive occurs. Further, I show that under certain conditions reduced recombination between these two loci is selectively favoured. These theoretical results provide clear, testable predictions about the nature of sexually antagonistic variation on driving chromosomes and have implications for the evolution of genomic architecture.

  16. Confirmation of Single-Locus Sex Determination and Female Heterogamety in Willow Based on Linkage Analysis

    PubMed Central

    Fang, Lecheng; Li, Xiaoping; Yin, Tongming

    2016-01-01

    In this study, we constructed high-density genetic maps of Salix suchowensis and mapped the gender locus with an F1 pedigree. Genetic maps were separately constructed for the maternal and paternal parents by using amplified fragment length polymorphism (AFLP) markers and the pseudo-testcross strategy. The maternal map consisted of 20 linkage groups that spanned a genetic distance of 2333.3 cM; whereas the paternal map contained 21 linkage groups that covered 2260 cM. Based on the established genetic maps, it was found that the gender of willow was determined by a single locus on linkage group LG_03, and the female was the heterogametic gender. Aligned with mapped SSR markers, linkage group LG_03 was found to be associated with chromosome XV in willow. It is noteworthy that marker density in the vicinity of the gender locus was significantly higher than that expected by chance alone, which indicates severe recombination suppression around the gender locus. In conclusion, this study confirmed the findings on the single-locus sex determination and female heterogamety in willow. It also provided additional evidence that validated the previous studies, which found that different autosomes evolved into sex chromosomes between the sister genera of Salix (willow) and Populus (poplar). PMID:26828940

  17. VNTR internal structure mapping at the {alpha}-globin 3{prime}HVR locus reveals a hierachy of related lineages in oceania

    SciTech Connect

    Martinson, J.J.; Clegg, J.B.; Boyce, A.J.

    1994-09-01

    Analysis of the {alpha}-globin gene complex in Oceania has revealed many different rearrangements which remove one of the adult globin genes. Frequencies of these deletion chromosomes are elevated by malarial resistance conferred by the resulting {alpha}-thalassaemia. One particular deletion chromosome, designated -{alpha}{sup 3.7}III, is found at high levels in Melanesia and Polynesia: RFLP haplotype analysis shows that this deletion is always found on chromosomes bearing the IIIa haplotype and is likely to be the product of one single rearrangement event. A subset of the -{alpha}{sup 3.7}III chromosomes carries a more recent mutation which generates the haemoglobin variant HbJ{sup Tongariki}. We have characterized the allelic variation at the 3{prime}HVR VNTR locus located 6 kb from the globin genes in each of these groups of chromosomes. We have determined the internal structure of these alleles by RFLP mapping of PCR-amplified DNA: within each group, the allelic diversity results from the insertion and/or deletion of small {open_quotes}motifs{close_quotes} of up to 6 adjacent repeats. Mapping of 3{prime}HVR alleles associated with other haplotypes reveals that these are composed of repeat arrays that are substantially different to those derived from IIIa chromosomes, indicating that interchromosomal recombination between heterologous haplotypes does not account for any of the diversity seen to date. We have recently shown that allelic size variation at the two VNTR loci flanking the {alpha}-globin complex is very closely linked to the haplotypes known to be present at this locus. Here we show that, within a haplotype, VNTR alleles are very closely related to each other on the basis of internal structure and demonstrate that intrachromosomal mutation processes involving small numbers of tandem repeats are the main cause of variation at this locus.

  18. Mapping of Mcs30, a New Mammary Carcinoma Susceptibility Quantitative Trait Locus (QTL30) on Rat Chromosome 12: Identification of Fry as a Candidate Mcs Gene

    PubMed Central

    Ren, Xuefeng; Graham, Jessica C.; Jing, Lichen; Mikheev, Andrei M.; Gao, Yuan; Lew, Jenny Pan; Xie, Hong; Kim, Andrea S.; Shang, Xiuling; Friedman, Cynthia; Vail, Graham; Fang, Ming Zhu; Bromberg, Yana; Zarbl, Helmut

    2013-01-01

    Rat strains differ dramatically in their susceptibility to mammary carcinogenesis. On the assumption that susceptibility genes are conserved across mammalian species and hence inform human carcinogenesis, numerous investigators have used genetic linkage studies in rats to identify genes responsible for differential susceptibility to carcinogenesis. Using a genetic backcross between the resistant Copenhagen (Cop) and susceptible Fischer 344 (F344) strains, we mapped a novel mammary carcinoma susceptibility (Mcs30) locus to the centromeric region on chromosome 12 (LOD score of ∼8.6 at the D12Rat59 marker). The Mcs30 locus comprises approximately 12 Mbp on the long arm of rat RNO12 whose synteny is conserved on human chromosome 13q12 to 13q13. After analyzing numerous genes comprising this locus, we identified Fry, the rat ortholog of the furry gene of Drosophila melanogaster, as a candidate Mcs gene. We cloned and determined the complete nucleotide sequence of the 13 kbp Fry mRNA. Sequence analysis indicated that the Fry gene was highly conserved across evolution, with 90% similarity of the predicted amino acid sequence among eutherian mammals. Comparison of the Fry sequence in the Cop and F344 strains identified two non-synonymous single nucleotide polymorphisms (SNPs), one of which creates a putative, de novo phosphorylation site. Further analysis showed that the expression of the Fry gene is reduced in a majority of rat mammary tumors. Our results also suggested that FRY activity was reduced in human breast carcinoma cell lines as a result of reduced levels or mutation. This study is the first to identify the Fry gene as a candidate Mcs gene. Our data suggest that the SNPs within the Fry gene contribute to the genetic susceptibility of the F344 rat strain to mammary carcinogenesis. These results provide the foundation for analyzing the role of the human FRY gene in cancer susceptibility and progression. PMID:24023717

  19. QTL mapping of powdery mildew resistance in WI 2757 cucumber (Cucumis sativus L.).

    PubMed

    He, Xiaoming; Li, Yuhong; Pandey, Sudhakar; Yandell, Brain S; Pathak, Mamta; Weng, Yiqun

    2013-08-01

    Powdery mildew (PM) is a very important disease of cucumber (Cucumis sativus L.). Resistant cultivars have been deployed in production for a long time, but the genetic mechanisms of PM resistance in cucumber are not well understood. A 3-year QTL mapping study of PM resistance was conducted with 132 F2:3 families derived from two cucumber inbred lines WI 2757 (resistant) and True Lemon (susceptible). A genetic map covering 610.4 cM in seven linkage groups was developed with 240 SSR marker loci. Multiple QTL mapping analysis of molecular marker data and disease index of the hypocotyl, cotyledon and true leaf for responses to PM inoculation identified six genomic regions in four chromosomes harboring QTL for PM resistance in WI 2757. Among the six QTL, pm1.1 and pm1.2 in chromosome 1 conferred leaf resistance. Minor QTL pm3.1 (chromosome 3) and pm4.1 (chromosome 4) contributed to disease susceptibility. The two major QTL, pm5.1 and pm5.2 were located in an interval of ~40 cM in chromosome 5 with each explaining 21.0-74.5 % phenotypic variations. Data presented herein support two recessively inherited, linked major QTL in chromosome 5 plus minor QTL in other chromosomes that control the PM resistance in WI 2757. The QTL pm5.2 for hypocotyl resistance plays the most important role in host resistance. Multiple observations in the same year revealed the importance of scoring time in the detection of PM resistance QTL. Results of this study provided new insights into phenotypic and genetic mechanisms of powdery mildew resistance in cucumber.

  20. QTL mapping of powdery mildew resistance in WI 2757 cucumber (Cucumis sativus L.).

    PubMed

    He, Xiaoming; Li, Yuhong; Pandey, Sudhakar; Yandell, Brain S; Pathak, Mamta; Weng, Yiqun

    2013-08-01

    Powdery mildew (PM) is a very important disease of cucumber (Cucumis sativus L.). Resistant cultivars have been deployed in production for a long time, but the genetic mechanisms of PM resistance in cucumber are not well understood. A 3-year QTL mapping study of PM resistance was conducted with 132 F2:3 families derived from two cucumber inbred lines WI 2757 (resistant) and True Lemon (susceptible). A genetic map covering 610.4 cM in seven linkage groups was developed with 240 SSR marker loci. Multiple QTL mapping analysis of molecular marker data and disease index of the hypocotyl, cotyledon and true leaf for responses to PM inoculation identified six genomic regions in four chromosomes harboring QTL for PM resistance in WI 2757. Among the six QTL, pm1.1 and pm1.2 in chromosome 1 conferred leaf resistance. Minor QTL pm3.1 (chromosome 3) and pm4.1 (chromosome 4) contributed to disease susceptibility. The two major QTL, pm5.1 and pm5.2 were located in an interval of ~40 cM in chromosome 5 with each explaining 21.0-74.5 % phenotypic variations. Data presented herein support two recessively inherited, linked major QTL in chromosome 5 plus minor QTL in other chromosomes that control the PM resistance in WI 2757. The QTL pm5.2 for hypocotyl resistance plays the most important role in host resistance. Multiple observations in the same year revealed the importance of scoring time in the detection of PM resistance QTL. Results of this study provided new insights into phenotypic and genetic mechanisms of powdery mildew resistance in cucumber. PMID:23689747