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Sample records for hsd17b locus centromeric

  1. Genetic variation in the HSD17B1 gene and risk of prostate cancer.

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    Peter Kraft

    2005-11-01

    Full Text Available Steroid hormones are believed to play an important role in prostate carcinogenesis, but epidemiological evidence linking prostate cancer and steroid hormone genes has been inconclusive, in part due to small sample sizes or incomplete characterization of genetic variation at the locus of interest. Here we report on the results of a comprehensive study of the association between HSD17B1 and prostate cancer by the Breast and Prostate Cancer Cohort Consortium, a large collaborative study. HSD17B1 encodes 17beta-hydroxysteroid dehydrogenase 1, an enzyme that converts dihydroepiandrosterone to the testosterone precursor Delta5-androsterone-3beta,17beta-diol and converts estrone to estradiol. The Breast and Prostate Cancer Cohort Consortium researchers systematically characterized variation in HSD17B1 by targeted resequencing and dense genotyping; selected haplotype-tagging single nucleotide polymorphisms (htSNPs that efficiently predict common variants in U.S. and European whites, Latinos, Japanese Americans, and Native Hawaiians; and genotyped these htSNPs in 8,290 prostate cancer cases and 9,367 study-, age-, and ethnicity-matched controls. We found no evidence that HSD17B1 htSNPs (including the nonsynonymous coding SNP S312G or htSNP haplotypes were associated with risk of prostate cancer or tumor stage in the pooled multiethnic sample or in U.S. and European whites. Analyses stratified by age, body mass index, and family history of disease found no subgroup-specific associations between these HSD17B1 htSNPs and prostate cancer. We found significant evidence of heterogeneity in associations between HSD17B1 haplotypes and prostate cancer across ethnicity: one haplotype had a significant (p < 0.002 inverse association with risk of prostate cancer in Latinos and Japanese Americans but showed no evidence of association in African Americans, Native Hawaiians, or whites. However, the smaller numbers of Latinos and Japanese Americans in this study makes

  2. HSD17B12 gene rs11037575 C>T polymorphism confers neuroblastoma susceptibility in a Southern Chinese population

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    Zhang ZR

    2017-04-01

    Full Text Available Zhuorong Zhang,1,2 Yan Zou,2 Jinhong Zhu,3 Ruizhong Zhang,2 Tianyou Yang,2 Fenghua Wang,2 Huimin Xia,1,2 Jing He,2 Zhichun Feng1,4–6 1Southern Medical University, Guangzhou, Guangdong, 2Department of Pediatric Surgery, Guangzhou Institute of Pediatrics, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, Guangdong, 3Molecular Epidemiology Laboratory, Department of Laboratory Medicine, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang, 4Division of Neonatology, Affiliated BaYi Children’s Hospital, Clinical Medical College in PLA Army General Hospital, Southern Medical University, 5National Engineering Laboratory for Birth Defects Prevention and Control of Key Technology, 6Beijing Key Laboratory of Pediatric Organ Failure, Beijing, People’s Republic of China Abstract: A previous genome-wide association study (GWAS identified four genetic polymorphisms (rs1027702 near DUSP12, rs10055201 in IL31RA, rs2619046 in DDX4, and rs11037575 in HSD17B12 gene that were associated with neuroblastoma susceptibility, especially for low-risk subjects. The aim of this study was to examine the association between these four polymorphisms and neuroblastoma susceptibility in a Southern Chinese population composed of 256 cases and 531 controls. Overall, among all the polymorphisms, single-locus analysis only revealed significant association between the HSD17B12 rs11037575 C>T polymorphism and neuroblastoma susceptibility (CT vs CC: adjusted odds ratio [OR] =0.71, 95% confidence interval [CI] =0.51–0.97, P=0.030. Moreover, stratified analysis indicated that the rs11037575 T allele was associated with decreased neuroblastoma risk among the children aged 0–18 months (adjusted OR =0.60, 95% CI =0.37–0.97, P=0.036; regarding the tumor site, this polymorphism protected against tumor in the mediastinum (adjusted OR =0.59, 95% CI =0.37–0.94, P=0.025. When risk genotypes were combined, we found that girls with

  3. Building a multigenic model of breast cancer susceptibility: CYP17 and HSD17B1 are two important candidates.

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    Feigelson, H S; McKean-Cowdin, R; Coetzee, G A; Stram, D O; Kolonel, L N; Henderson, B E

    2001-01-15

    We conducted a nested case-control study to evaluate whether polymorphisms in two genes involved in estrogen metabolism, CYP17 and HSD17B1, were useful in developing a breast cancer risk model that could help discriminate women who are at higher risk of breast cancer. If polymorphisms in these genes affect the level of circulating estrogens, they may directly influence breast cancer risk. The base population for this study is a multiethnic cohort study that includes African-American, Non-Latina White, Japanese, Latina, and Native Hawaiian women. For this analysis, 1508 randomly selected controls and 850 incident breast cancer cases of the first four ethnic groups who agreed to provide a blood specimen were included (76 and 80% response rates, respectively). The CYP17 A2 allele and the HSD17B1 A allele were considered "high-risk" alleles. Subjects were then classified according to number of high-risk alleles. After adjusting for age, weight, and ethnicity, we found that carrying one or more high-risk alleles increases the risk of advanced breast cancer in a dose-response fashion. The risk among women carrying four high-risk alleles was 2.21 [95% confidence interval (CI), 0.98-5.00; P for trend = 0.03] compared with those who carried none. This risk was largely limited to women who were not taking hormone replacement therapy (relative risk, 2.60; 95% CI, 0.95-7.14) and was most pronounced among those weighing 170 pounds or less (RR, 3.05; 95% CI, 1.29-7.25). These findings suggest that breast cancer risk has a strong genetic component and supports the theory that the underlying mechanism of "complex traits" can be understood using a multigenic model of candidate genes.

  4. Polymorphisms in HSD17B1: Early Onset and Increased Risk of Alzheimer’s Disease in Women with Down Syndrome

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    Joseph H. Lee

    2012-01-01

    Full Text Available Background/Aims. Genetic variants that affect estrogen activity may influence the risk of Alzheimer's disease (AD. In women with Down syndrome, we examined the relation of polymorphisms in hydroxysteroid-17beta-dehydrogenase (HSD17B1 to age at onset and risk of AD. HSD17B1 encodes the enzyme 17β-hydroxysteroid dehydrogenase (HSD1, which catalyzes the conversion of estrone to estradiol. Methods. Two hundred and thirty-eight women with DS, nondemented at baseline, 31–78 years of age, were followed at 14–18-month intervals for 4.5 years. Women were genotyped for 5 haplotype-tagging single-nucleotide polymorphisms (SNPs in the HSD17B1 gene region, and their association with incident AD was examined. Results. Age at onset was earlier, and risk of AD was elevated from two- to threefold among women homozygous for the minor allele at 3 SNPs in intron 4 (rs676387, exon 6 (rs605059, and exon 4 in COASY (rs598126. Carriers of the haplotype TCC, based on the risk alleles for these three SNPs, had an almost twofold increased risk of developing AD (hazard ratio = 1.8, 95% CI, 1.1–3.1. Conclusion. These findings support experimental and clinical studies of the neuroprotective role of estrogen.

  5. Genetic Variants in HSD17B3, SMAD3, and IPO11 Impact Circulating Lipids in Response to Fenofibrate in Individuals With Type 2 Diabetes.

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    Rotroff, Daniel M; Pijut, Sonja S; Marvel, Skylar W; Jack, John R; Havener, Tammy M; Pujol, Aurora; Schluter, Agatha; Graf, Gregory A; Ginsberg, Henry N; Shah, Hetal S; Gao, He; Morieri, Mario-Luca; Doria, Alessandro; Mychaleckyi, Josyf C; McLeod, Howard L; Buse, John B; Wagner, Michael J; Motsinger-Reif, Alison A

    2018-04-01

    Individuals with type 2 diabetes (T2D) and dyslipidemia are at an increased risk of cardiovascular disease. Fibrates are a class of drugs prescribed to treat dyslipidemia, but variation in response has been observed. To evaluate common and rare genetic variants that impact lipid responses to fenofibrate in statin-treated patients with T2D, we examined lipid changes in response to fenofibrate therapy using a genomewide association study (GWAS). Associations were followed-up using gene expression studies in mice. Common variants in SMAD3 and IPO11 were marginally associated with lipid changes in black subjects (P < 5 × 10 -6 ). Rare variant and gene expression changes were assessed using a false discovery rate approach. AKR7A3 and HSD17B13 were associated with lipid changes in white subjects (q < 0.2). Mice fed fenofibrate displayed reductions in Hsd17b13 gene expression (q < 0.1). Associations of variants in SMAD3, IPO11, and HSD17B13, with gene expression changes in mice indicate that transforming growth factor-beta (TGF-β) and NRF2 signaling pathways may influence fenofibrate effects on dyslipidemia in patients with T2D. © 2017 American Society for Clinical Pharmacology and Therapeutics.

  6. Dioxin exposure reduces the steroidogenic capacity of mouse antral follicles mainly at the level of HSD17B1 without altering atresia

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    Karman, Bethany N., E-mail: bklement@illinois.edu; Basavarajappa, Mallikarjuna S., E-mail: mbshivapur@gmail.com; Hannon, Patrick, E-mail: phannon2@illinois.edu; Flaws, Jodi A., E-mail: jflaws@illinois.edu

    2012-10-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a potent ovarian toxicant. Previously, we demonstrated that in vitro TCDD (1 nM) exposure decreases production/secretion of the sex steroid hormones progesterone (P4), androstenedione (A4), testosterone (T), and 17β-estradiol (E2) in mouse antral follicles. The purpose of this study was to determine the mechanism by which TCDD inhibits steroidogenesis. Specifically, we examined the effects of TCDD on the steroidogenic enzymes, atresia, and the aryl hydrocarbon receptor (AHR) protein. TCDD exposure for 48 h increased levels of A4, without changing HSD3B1 protein, HSD17B1 protein, estrone (E1), T or E2 levels. Further, TCDD did not alter atresia ratings compared to vehicle at 48 h. TCDD, however, did down regulate the AHR protein at 48 h. TCDD exposure for 96 h decreased transcript levels for Cyp11a1, Cyp17a1, Hsd17b1, and Cyp19a1, but increased Hsd3b1 transcript. TCDD exposure particularly lowered both Hsd17b1 transcript and HSD17B1 protein. However, TCDD exposure did not affect levels of E1 in the media nor atresia ratings at 96 h. TCDD, however, decreased levels of the proapoptotic factor Bax. Collectively, these data suggest that TCDD exposure causes a major block in the steroidogenic enzyme conversion of A4 to T and E1 to E2 and that it regulates apoptotic pathways, favoring survival over death in antral follicles. Finally, the down‐regulation of the AHR protein in TCDD exposed follicles persisted at 96 h, indicating that the activation and proteasomal degradation of this receptor likely plays a central role in the impaired steroidogenic capacity and altered apoptotic pathway of exposed antral follicles. -- Highlights: ► TCDD disrupts steroidogenic enzymes in mouse antral follicles. ► TCDD particularly affects the HSD17B1 enzyme in mouse antral follicles. ► TCDD does not affect atresia ratings in mouse antral follicles. ► TCDD decreases levels of the proapoptitic factor Bax in mouse antral follicles.

  7. Specific combination of compound heterozygous mutations in 17β-hydroxysteroid dehydrogenase type 4 (HSD17B4 defines a new subtype of D-bifunctional protein deficiency

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    McMillan Hugh J

    2012-11-01

    Full Text Available Abstract Background D-bifunctional protein (DBP deficiency is typically apparent within the first month of life with most infants demonstrating hypotonia, psychomotor delay and seizures. Few children survive beyond two years of age. Among patients with prolonged survival all demonstrate severe gross motor delay, absent language development, and severe hearing and visual impairment. DBP contains three catalytically active domains; an N-terminal dehydrogenase, a central hydratase and a C-terminal sterol carrier protein-2-like domain. Three subtypes of the disease are identified based upon the domain affected; DBP type I results from a combined deficiency of dehydrogenase and hydratase activity; DBP type II from isolated hydratase deficiency and DBP type III from isolated dehydrogenase deficiency. Here we report two brothers (16½ and 14 years old with DBP deficiency characterized by normal early childhood followed by sensorineural hearing loss, progressive cerebellar and sensory ataxia and subclinical retinitis pigmentosa. Methods and results Biochemical analysis revealed normal levels of plasma VLCFA, phytanic acid and pristanic acid, and normal bile acids in urine; based on these results no diagnosis was made. Exome analysis was performed using the Agilent SureSelect 50Mb All Exon Kit and the Illumina HiSeq 2000 next-generation-sequencing (NGS platform. Compound heterozygous mutations were identified by exome sequencing and confirmed by Sanger sequencing within the dehydrogenase domain (c.101C>T; p.Ala34Val and hydratase domain (c.1547T>C; p.Ile516Thr of the 17β-hydroxysteroid dehydrogenase type 4 gene (HSD17B4. These mutations have been previously reported in patients with severe-forms of DBP deficiency, however each mutation was reported in combination with another mutation affecting the same domain. Subsequent studies in fibroblasts revealed normal VLCFA levels, normal C26:0 but reduced pristanic acid beta-oxidation activity. Both DBP

  8. Different patterns of evolution in the centromeric and telomeric regions of group A and B haplotypes of the human killer cell Ig-like receptor locus.

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    Chul-Woo Pyo

    Full Text Available The fast evolving human KIR gene family encodes variable lymphocyte receptors specific for polymorphic HLA class I determinants. Nucleotide sequences for 24 representative human KIR haplotypes were determined. With three previously defined haplotypes, this gave a set of 12 group A and 15 group B haplotypes for assessment of KIR variation. The seven gene-content haplotypes are all combinations of four centromeric and two telomeric motifs. 2DL5, 2DS5 and 2DS3 can be present in centromeric and telomeric locations. With one exception, haplotypes having identical gene content differed in their combinations of KIR alleles. Sequence diversity varied between haplotype groups and between centromeric and telomeric halves of the KIR locus. The most variable A haplotype genes are in the telomeric half, whereas the most variable genes characterizing B haplotypes are in the centromeric half. Of the highly polymorphic genes, only the 3DL3 framework gene exhibits a similar diversity when carried by A and B haplotypes. Phylogenetic analysis and divergence time estimates, point to the centromeric gene-content motifs that distinguish A and B haplotypes having emerged ~6 million years ago, contemporaneously with the separation of human and chimpanzee ancestors. In contrast, the telomeric motifs that distinguish A and B haplotypes emerged more recently, ~1.7 million years ago, before the emergence of Homo sapiens. Thus the centromeric and telomeric motifs that typify A and B haplotypes have likely been present throughout human evolution. The results suggest the common ancestor of A and B haplotypes combined a B-like centromeric region with an A-like telomeric region.

  9. The Past, Present, and Future of Human Centromere Genomics

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    Megan E. Aldrup-MacDonald

    2014-01-01

    Full Text Available The centromere is the chromosomal locus essential for chromosome inheritance and genome stability. Human centromeres are located at repetitive alpha satellite DNA arrays that compose approximately 5% of the genome. Contiguous alpha satellite DNA sequence is absent from the assembled reference genome, limiting current understanding of centromere organization and function. Here, we review the progress in centromere genomics spanning the discovery of the sequence to its molecular characterization and the work done during the Human Genome Project era to elucidate alpha satellite structure and sequence variation. We discuss exciting recent advances in alpha satellite sequence assembly that have provided important insight into the abundance and complex organization of this sequence on human chromosomes. In light of these new findings, we offer perspectives for future studies of human centromere assembly and function.

  10. Dynamic epigenetic states of maize centromeres

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    Yalin eLiu

    2015-10-01

    Full Text Available The centromere is a specialized chromosomal region identified as the major constriction, upon which the kinetochore complex is formed, ensuring accurate chromosome orientation and segregation during cell division. The rapid evolution of centromere DNA sequence and the conserved centromere function are two contradictory aspects of centromere biology. Indeed, the sole presence of genetic sequence is not sufficient for centromere formation. Various dicentric chromosomes with one inactive centromere have been recognized. It has also been found that de novo centromere formation is common on fragments in which centromeric DNA sequences are lost. Epigenetic factors play important roles in centromeric chromatin assembly and maintenance. Nondisjunction of the supernumerary B chromosome early prophase of meiosis I requires an active centromere. This review discusses recent studies in maize about genetic and epigenetic elements regulating formation and maintenance of centromere chromatin, as well as centromere behavior in meiosis.

  11. Recent advances in plant centromere biology.

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    Feng, Chao; Liu, YaLin; Su, HanDong; Wang, HeFei; Birchler, James; Han, FangPu

    2015-03-01

    The centromere, which is one of the essential parts of a chromosome, controls kinetochore formation and chromosome segregation during mitosis and meiosis. While centromere function is conserved in eukaryotes, the centromeric DNA sequences evolve rapidly and have few similarities among species. The histone H3 variant CENH3 (CENP-A in human), which mostly exists in centromeric nucleosomes, is a universal active centromere mark in eukaryotes and plays an essential role in centromere identity determination. The relationship between centromeric DNA sequences and centromere identity determination is one of the intriguing questions in studying centromere formation. Due to the discoveries in the past decades, including "neocentromeres" and "centromere inactivation", it is now believed that the centromere identity is determined by epigenetic mechanisms. This review will present recent progress in plant centromere biology.

  12. The major horse satellite DNA family is associated with centromere competence.

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    Cerutti, Federico; Gamba, Riccardo; Mazzagatti, Alice; Piras, Francesca M; Cappelletti, Eleonora; Belloni, Elisa; Nergadze, Solomon G; Raimondi, Elena; Giulotto, Elena

    2016-01-01

    The centromere is the specialized locus required for correct chromosome segregation during cell division. The DNA of most eukaryotic centromeres is composed of extended arrays of tandem repeats (satellite DNA). In the horse, we previously showed that, although the centromere of chromosome 11 is completely devoid of tandem repeat arrays, all other centromeres are characterized by the presence of satellite DNA. We isolated three horse satellite DNA sequences (37cen, 2P1 and EC137) and described their chromosomal localization in four species of the genus Equus. In the work presented here, using the ChIP-seq methodology, we showed that, in the horse, the 37cen satellite binds CENP-A, the centromere-specific histone-H3 variant. The 37cen sequence bound by CENP-A is GC-rich with 221 bp units organized in a head-to-tail fashion. The physical interaction of CENP-A with 37cen was confirmed through slot blot experiments. Immuno-FISH on stretched chromosomes and chromatin fibres demonstrated that the extension of satellite DNA stretches is variable and is not related to the organization of CENP-A binding domains. Finally, we proved that the centromeric satellite 37cen is transcriptionally active. Our data offer new insights into the organization of horse centromeres. Although three different satellite DNA families are cytogenetically located at centromeres, only the 37cen family is associated to the centromeric function. Moreover, similarly to other species, CENP-A binding domains are variable in size. The transcriptional competence of the 37cen satellite that we observed adds new evidence to the hypothesis that centromeric transcripts may be required for centromere function.

  13. Structure, Function, and Evolution of Rice Centromeres

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    Jiang, Jiming

    2010-02-04

    The centromere is the most characteristic landmark of eukaryotic chromosomes. Centromeres function as the site for kinetochore assembly and spindle attachment, allowing for the faithful pairing and segregation of sister chromatids during cell division. Characterization of centromeric DNA is not only essential to understand the structure and organization of plant genomes, but it is also a critical step in the development of plant artificial chromosomes. The centromeres of most model eukaryotic species, consist predominantly of long arrays of satellite DNA. Determining the precise DNA boundary of a centromere has proven to be a difficult task in multicellular eukaryotes. We have successfully cloned and sequenced the centromere of rice chromosome 8 (Cen8), representing the first fully sequenced centromere from any multicellular eukaryotes. The functional core of Cen8 spans ~800 kb of DNA, which was determined by chromatin immunoprecipitation (ChIP) using an antibody against the rice centromere-specific H3 histone. We discovered 16 actively transcribed genes distributed throughout the Cen8 region. In addition to Cen8, we have characterized eight additional rice centromeres using the next generation sequencing technology. We discovered four subfamilies of the CRR retrotransposon that is highly enriched in rice centromeres. CRR elements are constitutively transcribed and different CRR subfamilies are differentially processed by RNAi. These results suggest that different CRR subfamilies may play different roles in the RNAi-mediated pathway for formation and maintenance of centromeric chromatin.

  14. Centromere pairing by a plasmid-encoded type I ParB protein

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    Ringgaard, Simon; Löwe, Jan; Gerdes, Kenn

    2007-01-01

    The par2 locus of Escherichia coli plasmid pB171 encodes two trans-acting proteins, ParA and ParB, and two cis-acting sites, parC1 and parC2, to which ParB binds cooperatively. ParA is related to MinD and oscillates in helical structures and thereby positions ParB/parC-carrying plasmids regularly......, hence identifying the N terminus of ParB as a requirement for ParB-mediated centromere pairing. These observations suggest that centromere pairing is an important intermediate step in plasmid partitioning mediated by the common type I loci....

  15. Centromeric heterochromatin: the primordial segregation machine.

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    Bloom, Kerry S

    2014-01-01

    Centromeres are specialized domains of heterochromatin that provide the foundation for the kinetochore. Centromeric heterochromatin is characterized by specific histone modifications, a centromere-specific histone H3 variant (CENP-A), and the enrichment of cohesin, condensin, and topoisomerase II. Centromere DNA varies orders of magnitude in size from 125 bp (budding yeast) to several megabases (human). In metaphase, sister kinetochores on the surface of replicated chromosomes face away from each other, where they establish microtubule attachment and bi-orientation. Despite the disparity in centromere size, the distance between separated sister kinetochores is remarkably conserved (approximately 1 μm) throughout phylogeny. The centromere functions as a molecular spring that resists microtubule-based extensional forces in mitosis. This review explores the physical properties of DNA in order to understand how the molecular spring is built and how it contributes to the fidelity of chromosome segregation.

  16. De Novo Centromere Formation and Centromeric Sequence Expansion in Wheat and its Wide Hybrids.

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    Xiang Guo

    2016-04-01

    Full Text Available Centromeres typically contain tandem repeat sequences, but centromere function does not necessarily depend on these sequences. We identified functional centromeres with significant quantitative changes in the centromeric retrotransposons of wheat (CRW contents in wheat aneuploids (Triticum aestivum and the offspring of wheat wide hybrids. The CRW signals were strongly reduced or essentially lost in some wheat ditelosomic lines and in the addition lines from the wide hybrids. The total loss of the CRW sequences but the presence of CENH3 in these lines suggests that the centromeres were formed de novo. In wheat and its wide hybrids, which carry large complex genomes or no sequenced genome, we performed CENH3-ChIP-dot-blot methods alone or in combination with CENH3-ChIP-seq and identified the ectopic genomic sequences present at the new centromeres. In adcdition, the transcription of the identified DNA sequences was remarkably increased at the new centromere, suggesting that the transcription of the corresponding sequences may be associated with de novo centromere formation. Stable alien chromosomes with two and three regions containing CRW sequences induced by centromere breakage were observed in the wheat-Th. elongatum hybrid derivatives, but only one was a functional centromere. In wheat-rye (Secale cereale hybrids, the rye centromere-specific sequences spread along the chromosome arms and may have caused centromere expansion. Frequent and significant quantitative alterations in the centromere sequence via chromosomal rearrangement have been systematically described in wheat wide hybridizations, which may affect the retention or loss of the alien chromosomes in the hybrids. Thus, the centromere behavior in wide crosses likely has an important impact on the generation of biodiversity, which ultimately has implications for speciation.

  17. D-bifunctional protein deficiency associated with drug resistant infantile spasms

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    Buoni, Sabrina; Zannolli, Raffaella; Waterham, Hans; Wanders, Ronald; Fois, Alberto

    2007-01-01

    Peroxisomal disorders appear with a frequency of about 1:5000 in newborns. Peroxisomal D-bifunctional protein (D-BP), encoded by the HSD17B4 gene (gene ID: 3294; locus tag: HGNC:5213, chromosome 5q2; official symbol: HSD17B4; name: hydroxysteroid (17-beta) dehydrogenase; gene type: protein coding)

  18. DNA topoisomerase III localizes to centromeres and affects centromeric CENP-A levels in fission yeast.

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    Ulrika Norman-Axelsson

    Full Text Available Centromeres are specialized chromatin regions marked by the presence of nucleosomes containing the centromere-specific histone H3 variant CENP-A, which is essential for chromosome segregation. Assembly and disassembly of nucleosomes is intimately linked to DNA topology, and DNA topoisomerases have previously been implicated in the dynamics of canonical H3 nucleosomes. Here we show that Schizosaccharomyces pombe Top3 and its partner Rqh1 are involved in controlling the levels of CENP-A(Cnp1 at centromeres. Both top3 and rqh1 mutants display defects in chromosome segregation. Using chromatin immunoprecipitation and tiling microarrays, we show that Top3, unlike Top1 and Top2, is highly enriched at centromeric central domains, demonstrating that Top3 is the major topoisomerase in this region. Moreover, centromeric Top3 occupancy positively correlates with CENP-A(Cnp1 occupancy. Intriguingly, both top3 and rqh1 mutants display increased relative enrichment of CENP-A(Cnp1 at centromeric central domains. Thus, Top3 and Rqh1 normally limit the levels of CENP-A(Cnp1 in this region. This new role is independent of the established function of Top3 and Rqh1 in homologous recombination downstream of Rad51. Therefore, we hypothesize that the Top3-Rqh1 complex has an important role in controlling centromere DNA topology, which in turn affects the dynamics of CENP-A(Cnp1 nucleosomes.

  19. Epigenetic Regulation of Centromere Chromatin Stability by Dietary and Environmental Factors.

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    Hernández-Saavedra, Diego; Strakovsky, Rita S; Ostrosky-Wegman, Patricia; Pan, Yuan-Xiang

    2017-11-01

    The centromere is a genomic locus required for the segregation of the chromosomes during cell division. This chromosomal region together with pericentromeres has been found to be susceptible to damage, and thus the perturbation of the centromere could lead to the development of aneuploidic events. Metabolic abnormalities that underlie the generation of cancer include inflammation, oxidative stress, cell cycle deregulation, and numerous others. The micronucleus assay, an early clinical marker of cancer, has been shown to provide a reliable measure of genotoxic damage that may signal cancer initiation. In the current review, we will discuss the events that lead to micronucleus formation and centromeric and pericentromeric chromatin instability, as well transcripts emanating from these regions, which were previously thought to be inactive. Studies were selected in PubMed if they reported the effects of nutritional status (macro- and micronutrients) or environmental toxicant exposure on micronucleus frequency or any other chromosomal abnormality in humans, animals, or cell models. Mounting evidence from epidemiologic, environmental, and nutritional studies provides a novel perspective on the origination of aneuploidic events. Although substantial evidence exists describing the role that nutritional status and environmental toxicants have on the generation of micronuclei and other nuclear aberrations, limited information is available to describe the importance of macro- and micronutrients on centromeric and pericentromeric chromatin stability. Moving forward, studies that specifically address the direct link between nutritional status, excess, or deficiency and the epigenetic regulation of the centromere will provide much needed insight into the nutritional and environmental regulation of this chromosomal region and the initiation of aneuploidy. © 2017 American Society for Nutrition.

  20. Characterization of centromeric histone H3 (CENH3 variants in cultivated and wild carrots (Daucus sp..

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    Frank Dunemann

    Full Text Available In eukaryotes, centromeres are the assembly sites for the kinetochore, a multi-protein complex to which spindle microtubules are attached at mitosis and meiosis, thereby ensuring segregation of chromosomes during cell division. They are specified by incorporation of CENH3, a centromere specific histone H3 variant which replaces canonical histone H3 in the nucleosomes of functional centromeres. To lay a first foundation of a putative alternative haploidization strategy based on centromere-mediated genome elimination in cultivated carrots, in the presented research we aimed at the identification and cloning of functional CENH3 genes in Daucus carota and three distantly related wild species of genus Daucus varying in basic chromosome numbers. Based on mining the carrot transcriptome followed by a subsequent PCR-based cloning, homologous coding sequences for CENH3s of the four Daucus species were identified. The ORFs of the CENH3 variants were very similar, and an amino acid sequence length of 146 aa was found in three out of the four species. Comparison of Daucus CENH3 amino acid sequences with those of other plant CENH3s as well as their phylogenetic arrangement among other dicot CENH3s suggest that the identified genes are authentic CENH3 homologs. To verify the location of the CENH3 protein in the kinetochore regions of the Daucus chromosomes, a polyclonal antibody based on a peptide corresponding to the N-terminus of DcCENH3 was developed and used for anti-CENH3 immunostaining of mitotic root cells. The chromosomal location of CENH3 proteins in the centromere regions of the chromosomes could be confirmed. For genetic localization of the CENH3 gene in the carrot genome, a previously constructed linkage map for carrot was used for mapping a CENH3-specific simple sequence repeat (SSR marker, and the CENH3 locus was mapped on the carrot chromosome 9.

  1. RNAi and heterochromatin repress centromeric meiotic recombination

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    Ellermeier, Chad; Higuchi, Emily C; Phadnis, Naina

    2010-01-01

    During meiosis, the formation of viable haploid gametes from diploid precursors requires that each homologous chromosome pair be properly segregated to produce an exact haploid set of chromosomes. Genetic recombination, which provides a physical connection between homologous chromosomes, is essen......During meiosis, the formation of viable haploid gametes from diploid precursors requires that each homologous chromosome pair be properly segregated to produce an exact haploid set of chromosomes. Genetic recombination, which provides a physical connection between homologous chromosomes....... Surprisingly, one mutant derepressed for recombination in the heterochromatic mating-type region during meiosis and several mutants derepressed for centromeric gene expression during mitotic growth are not derepressed for centromeric recombination during meiosis. These results reveal a complex relation between...... types of repression by heterochromatin. Our results also reveal a previously undemonstrated role for RNAi and heterochromatin in the repression of meiotic centromeric recombination and, potentially, in the prevention of birth defects by maintenance of proper chromosome segregation during meiosis....

  2. Repeatless and Repeat-Based Centromeres in Potato: Implications for Centromere Evolution[C][W

    Czech Academy of Sciences Publication Activity Database

    Gong, Z.; Wu, Y.; Koblížková, Andrea; Torres, G.A.; Wang, K.; Iovene, M.; Neumann, Pavel; Zhang, W.; Novák, Petr; Buell, C.R.; Macas, Jiří; Jiang, J.

    2012-01-01

    Roč. 24, č. 9 (2012), s. 3559-3574 ISSN 1040-4651 R&D Projects: GA MŠk(CZ) LH11058 Institutional research plan: CEZ:AV0Z50510513 Institutional support: RVO:60077344 Keywords : repetitive sequences * plant satellite repeats * Arabidopsis thaliana * rice centromere * wild potatoes Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 9.251, year: 2012

  3. HACking the centromere chromatin code: insights from human artificial chromosomes.

    Science.gov (United States)

    Bergmann, Jan H; Martins, Nuno M C; Larionov, Vladimir; Masumoto, Hiroshi; Earnshaw, William C

    2012-07-01

    The centromere is a specialized chromosomal region that serves as the assembly site of the kinetochore. At the centromere, CENP-A nucleosomes form part of a chromatin landscape termed centrochromatin. This chromatin environment conveys epigenetic marks regulating kinetochore formation. Recent work sheds light on the intricate relationship between centrochromatin state, the CENP-A assembly pathway and the maintenance of centromere function. Here, we review the emerging picture of how chromatin affects mammalian kinetochore formation. We place particular emphasis on data obtained from Human Artificial Chromosome (HAC) biology and the targeted engineering of centrochromatin using synthetic HACs. We discuss implications of these findings, which indicate that a delicate balance of histone modifications and chromatin state dictates both de novo centromere formation and the maintenance of centromere identity in dividing cell populations.

  4. Centromere Destiny in Dicentric Chromosomes: New Insights from the Evolution of Human Chromosome 2 Ancestral Centromeric Region.

    Science.gov (United States)

    Chiatante, Giorgia; Giannuzzi, Giuliana; Calabrese, Francesco Maria; Eichler, Evan E; Ventura, Mario

    2017-07-01

    Dicentric chromosomes are products of genomic rearrangements that place two centromeres on the same chromosome. Due to the presence of two primary constrictions, they are inherently unstable and overcome their instability by epigenetically inactivating and/or deleting one of the two centromeres, thus resulting in functionally monocentric chromosomes that segregate normally during cell division. Our understanding to date of dicentric chromosome formation, behavior and fate has been largely inferred from observational studies in plants and humans as well as artificially produced de novo dicentrics in yeast and in human cells. We investigate the most recent product of a chromosome fusion event fixed in the human lineage, human chromosome 2, whose stability was acquired by the suppression of one centromere, resulting in a unique difference in chromosome number between humans (46 chromosomes) and our most closely related ape relatives (48 chromosomes). Using molecular cytogenetics, sequencing, and comparative sequence data, we deeply characterize the relicts of the chromosome 2q ancestral centromere and its flanking regions, gaining insight into the ancestral organization that can be easily broadened to all acrocentric chromosome centromeres. Moreover, our analyses offered the opportunity to trace the evolutionary history of rDNA and satellite III sequences among great apes, thus suggesting a new hypothesis for the preferential inactivation of some human centromeres, including IIq. Our results suggest two possible centromere inactivation models to explain the evolutionarily stabilization of human chromosome 2 over the last 5-6 million years. Our results strongly favor centromere excision through a one-step process. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Identification of a fourth locus (EVR4) for familial exudative vitreoretinopathy (FEVR).

    Science.gov (United States)

    Toomes, Carmel; Downey, Louise M; Bottomley, Helen M; Scott, Sheila; Woodruff, Geoffrey; Trembath, Richard C; Inglehearn, Chris F

    2004-01-15

    Familial exudative vitreoretinopathy (FEVR) is a genetically heterogeneous inherited blinding disorder of the retinal vascular system. To date three loci have been mapped: EVR1 on chromosome 11q, EVR2 on chromosome Xp, and EVR3 on chromosome 11p. The gene underlying EVR3 remains unidentified whilst the EVR2 gene, which encodes the Norrie disease protein (NDP), was identified over a decade ago. More recently, FZD4, the gene that encodes the Wnt receptor Frizzled-4, was identified as the mutated gene at the EVR1 locus. The purpose of this study was to screen FZD4 in a large family previously proven to be linked to the EVR1 locus. PCR products were generated using genomic DNA from affected family members with primers designed to amplify the coding sequence of FZD4. The PCR products were screened for mutations by direct sequencing. Genotyping was performed in all available family members using fluorescently labeled microsatellite markers from chromosome 11q. Sequencing of the EVR1 gene, FZD4, in this family identified no mutation. To investigate this family further we performed high-resolution genotyping with markers spanning chromosome 11q. Haplotype analysis excluded FZD4 as the mutated gene in this family and identified a candidate region approximately 10 cM centromeric to EVR1. This new FEVR locus is flanked by markers D11S1368 (centromeric) and D11S937 (telomeric) and spans approximately 15 cM. High-resolution genotyping and haplotype analysis excluded FZD4 as the defective gene in a family previously linked to the EVR1 locus. The results indicate that the gene mutated in this family lies centromeric to the EVR1 gene, FZD4, and is also genetically distinct from the EVR3 locus. This new locus has been designated EVR4 and is the fourth FEVR locus to be described.

  6. Essential loci in centromeric heterochromatin of Drosophila melanogaster. I: the right arm of chromosome 2.

    Science.gov (United States)

    Coulthard, Alistair B; Alm, Christina; Cealiac, Iulia; Sinclair, Don A; Honda, Barry M; Rossi, Fabrizio; Dimitri, Patrizio; Hilliker, Arthur J

    2010-06-01

    With the most recent releases of the Drosophila melanogaster genome sequences, much of the previously absent heterochromatic sequences have now been annotated. We undertook an extensive genetic analysis of existing lethal mutations, as well as molecular mapping and sequence analysis (using a candidate gene approach) to identify as many essential genes as possible in the centromeric heterochromatin on the right arm of the second chromosome (2Rh) of D. melanogaster. We also utilized available RNA interference lines to knock down the expression of genes in 2Rh as another approach to identifying essential genes. In total, we verified the existence of eight novel essential loci in 2Rh: CG17665, CG17683, CG17684, CG17883, CG40127, CG41265, CG42595, and Atf6. Two of these essential loci, CG41265 and CG42595, are synonymous with the previously characterized loci l(2)41Ab and unextended, respectively. The genetic and molecular analysis of the previously reported locus, l(2)41Ae, revealed that this is not a single locus, but rather it is a large region of 2Rh that extends from unextended (CG42595) to CG17665 and includes four of the novel loci uncovered here.

  7. Recombination patterns reveal information about centromere location on linkage maps

    DEFF Research Database (Denmark)

    Limborg, Morten T.; McKinney, Garrett J.; Seeb, Lisa W.

    2016-01-01

    . mykiss) characterized by low and unevenly distributed recombination – a general feature of male meiosis in many species. Further, a high frequency of double crossovers along chromosome arms in barley reduced resolution for locating centromeric regions on most linkage groups. Despite these limitations...

  8. Evolutionary movement of centromeres in horse, donkey, and zebra.

    Science.gov (United States)

    Carbone, Lucia; Nergadze, Solomon G; Magnani, Elisa; Misceo, Doriana; Francesca Cardone, Maria; Roberto, Roberta; Bertoni, Livia; Attolini, Carmen; Francesca Piras, Maria; de Jong, Pieter; Raudsepp, Terje; Chowdhary, Bhanu P; Guérin, Gérard; Archidiacono, Nicoletta; Rocchi, Mariano; Giulotto, Elena

    2006-06-01

    Centromere repositioning (CR) is a recently discovered biological phenomenon consisting of the emergence of a new centromere along a chromosome and the inactivation of the old one. After a CR, the primary constriction and the centromeric function are localized in a new position while the order of physical markers on the chromosome remains unchanged. These events profoundly affect chromosomal architecture. Since horses, asses, and zebras, whose evolutionary divergence is relatively recent, show remarkable morphological similarity and capacity to interbreed despite their chromosomes differing considerably, we investigated the role of CR in the karyotype evolution of the genus Equus. Using appropriate panels of BAC clones in FISH experiments, we compared the centromere position and marker order arrangement among orthologous chromosomes of Burchelli's zebra (Equus burchelli), donkey (Equus asinus), and horse (Equus caballus). Surprisingly, at least eight CRs took place during the evolution of this genus. Even more surprisingly, five cases of CR have occurred in the donkey after its divergence from zebra, that is, in a very short evolutionary time (approximately 1 million years). These findings suggest that in some species the CR phenomenon could have played an important role in karyotype shaping, with potential consequences on population dynamics and speciation.

  9. Genome-wide analysis reveals a cell cycle–dependent mechanism controlling centromere propagation

    Science.gov (United States)

    Erhardt, Sylvia; Mellone, Barbara G.; Betts, Craig M.; Zhang, Weiguo; Karpen, Gary H.; Straight, Aaron F.

    2008-01-01

    Centromeres are the structural and functional foundation for kinetochore formation, spindle attachment, and chromosome segregation. In this study, we isolated factors required for centromere propagation using genome-wide RNA interference screening for defects in centromere protein A (CENP-A; centromere identifier [CID]) localization in Drosophila melanogaster. We identified the proteins CAL1 and CENP-C as essential factors for CID assembly at the centromere. CID, CAL1, and CENP-C coimmunoprecipitate and are mutually dependent for centromere localization and function. We also identified the mitotic cyclin A (CYCA) and the anaphase-promoting complex (APC) inhibitor RCA1/Emi1 as regulators of centromere propagation. We show that CYCA is centromere localized and that CYCA and RCA1/Emi1 couple centromere assembly to the cell cycle through regulation of the fizzy-related/CDH1 subunit of the APC. Our findings identify essential components of the epigenetic machinery that ensures proper specification and propagation of the centromere and suggest a mechanism for coordinating centromere inheritance with cell division. PMID:19047461

  10. Genome-wide analysis reveals a cell cycle-dependent mechanism controlling centromere propagation.

    Science.gov (United States)

    Erhardt, Sylvia; Mellone, Barbara G; Betts, Craig M; Zhang, Weiguo; Karpen, Gary H; Straight, Aaron F

    2008-12-01

    Centromeres are the structural and functional foundation for kinetochore formation, spindle attachment, and chromosome segregation. In this study, we isolated factors required for centromere propagation using genome-wide RNA interference screening for defects in centromere protein A (CENP-A; centromere identifier [CID]) localization in Drosophila melanogaster. We identified the proteins CAL1 and CENP-C as essential factors for CID assembly at the centromere. CID, CAL1, and CENP-C coimmunoprecipitate and are mutually dependent for centromere localization and function. We also identified the mitotic cyclin A (CYCA) and the anaphase-promoting complex (APC) inhibitor RCA1/Emi1 as regulators of centromere propagation. We show that CYCA is centromere localized and that CYCA and RCA1/Emi1 couple centromere assembly to the cell cycle through regulation of the fizzy-related/CDH1 subunit of the APC. Our findings identify essential components of the epigenetic machinery that ensures proper specification and propagation of the centromere and suggest a mechanism for coordinating centromere inheritance with cell division.

  11. SWI/SNF-like chromatin remodeling factor Fun30 supports point centromere function in S. cerevisiae.

    Directory of Open Access Journals (Sweden)

    Mickaël Durand-Dubief

    2012-09-01

    Full Text Available Budding yeast centromeres are sequence-defined point centromeres and are, unlike in many other organisms, not embedded in heterochromatin. Here we show that Fun30, a poorly understood SWI/SNF-like chromatin remodeling factor conserved in humans, promotes point centromere function through the formation of correct chromatin architecture at centromeres. Our determination of the genome-wide binding and nucleosome positioning properties of Fun30 shows that this enzyme is consistently enriched over centromeres and that a majority of CENs show Fun30-dependent changes in flanking nucleosome position and/or CEN core micrococcal nuclease accessibility. Fun30 deletion leads to defects in histone variant Htz1 occupancy genome-wide, including at and around most centromeres. FUN30 genetically interacts with CSE4, coding for the centromere-specific variant of histone H3, and counteracts the detrimental effect of transcription through centromeres on chromosome segregation and suppresses transcriptional noise over centromere CEN3. Previous work has shown a requirement for fission yeast and mammalian homologs of Fun30 in heterochromatin assembly. As centromeres in budding yeast are not embedded in heterochromatin, our findings indicate a direct role of Fun30 in centromere chromatin by promoting correct chromatin architecture.

  12. A regulatory effect of INMAP on centromere proteins: antisense INMAP induces CENP-B variation and centromeric halo.

    Directory of Open Access Journals (Sweden)

    Tan Tan

    Full Text Available CENP-B is a highly conserved protein that facilitates the assembly of specific centromere structures both in interphase nuclei and on mitotic chromosomes. INMAP is a conserved protein that localizes at nucleus in interphase cells and at mitotic apparatus in mitotic cells. Our previous results showed that INMAP over-expression leads to spindle defects, mitotic arrest and formation of polycentrosomal and multinuclear cells, indicating that INMAP may modulate the function of (a key protein(s in mitotic apparatus. In this study, we demonstrate that INMAP interacts with CENP-B and promotes cleavage of the N-terminal DNA binding domain from CENP-B. The cleaved CENP-B cannot associate with centromeres and thus lose its centromere-related functions. Consistent with these results, CENP-B in INMAP knockdown cells becomes more diffused around kinetochores. Although INMAP knockdown cells do not exhibit gross defects in mitotic spindle formation, these cells go through mitosis, especially prophase and metaphase, with different relative timing, indicating subtle abnormality. These results identify INMAP as a model regulator of CENP-B and support the notion that INMAP regulates mitosis through modulating CENP-B-mediated centromere organization.

  13. Uncoupling of satellite DNA and centromeric function in the genus Equus.

    Science.gov (United States)

    Piras, Francesca M; Nergadze, Solomon G; Magnani, Elisa; Bertoni, Livia; Attolini, Carmen; Khoriauli, Lela; Raimondi, Elena; Giulotto, Elena

    2010-02-12

    In a previous study, we showed that centromere repositioning, that is the shift along the chromosome of the centromeric function without DNA sequence rearrangement, has occurred frequently during the evolution of the genus Equus. In this work, the analysis of the chromosomal distribution of satellite tandem repeats in Equus caballus, E. asinus, E. grevyi, and E. burchelli highlighted two atypical features: 1) several centromeres, including the previously described evolutionary new centromeres (ENCs), seem to be devoid of satellite DNA, and 2) satellite repeats are often present at non-centromeric termini, probably corresponding to relics of ancestral now inactive centromeres. Immuno-FISH experiments using satellite DNA and antibodies against the kinetochore protein CENP-A demonstrated that satellite-less primary constrictions are actually endowed with centromeric function. The phylogenetic reconstruction of centromere repositioning events demonstrates that the acquisition of satellite DNA occurs after the formation of the centromere during evolution and that centromeres can function over millions of years and many generations without detectable satellite DNA. The rapidly evolving Equus species gave us the opportunity to identify different intermediate steps along the full maturation of ENCs.

  14. Uncoupling of satellite DNA and centromeric function in the genus Equus.

    Directory of Open Access Journals (Sweden)

    Francesca M Piras

    2010-02-01

    Full Text Available In a previous study, we showed that centromere repositioning, that is the shift along the chromosome of the centromeric function without DNA sequence rearrangement, has occurred frequently during the evolution of the genus Equus. In this work, the analysis of the chromosomal distribution of satellite tandem repeats in Equus caballus, E. asinus, E. grevyi, and E. burchelli highlighted two atypical features: 1 several centromeres, including the previously described evolutionary new centromeres (ENCs, seem to be devoid of satellite DNA, and 2 satellite repeats are often present at non-centromeric termini, probably corresponding to relics of ancestral now inactive centromeres. Immuno-FISH experiments using satellite DNA and antibodies against the kinetochore protein CENP-A demonstrated that satellite-less primary constrictions are actually endowed with centromeric function. The phylogenetic reconstruction of centromere repositioning events demonstrates that the acquisition of satellite DNA occurs after the formation of the centromere during evolution and that centromeres can function over millions of years and many generations without detectable satellite DNA. The rapidly evolving Equus species gave us the opportunity to identify different intermediate steps along the full maturation of ENCs.

  15. Genome-wide characterization of centromeric satellites from multiple mammalian genomes.

    Science.gov (United States)

    Alkan, Can; Cardone, Maria Francesca; Catacchio, Claudia Rita; Antonacci, Francesca; O'Brien, Stephen J; Ryder, Oliver A; Purgato, Stefania; Zoli, Monica; Della Valle, Giuliano; Eichler, Evan E; Ventura, Mario

    2011-01-01

    Despite its importance in cell biology and evolution, the centromere has remained the final frontier in genome assembly and annotation due to its complex repeat structure. However, isolation and characterization of the centromeric repeats from newly sequenced species are necessary for a complete understanding of genome evolution and function. In recent years, various genomes have been sequenced, but the characterization of the corresponding centromeric DNA has lagged behind. Here, we present a computational method (RepeatNet) to systematically identify higher-order repeat structures from unassembled whole-genome shotgun sequence and test whether these sequence elements correspond to functional centromeric sequences. We analyzed genome datasets from six species of mammals representing the diversity of the mammalian lineage, namely, horse, dog, elephant, armadillo, opossum, and platypus. We define candidate monomer satellite repeats and demonstrate centromeric localization for five of the six genomes. Our analysis revealed the greatest diversity of centromeric sequences in horse and dog in contrast to elephant and armadillo, which showed high-centromeric sequence homogeneity. We could not isolate centromeric sequences within the platypus genome, suggesting that centromeres in platypus are not enriched in satellite DNA. Our method can be applied to the characterization of thousands of other vertebrate genomes anticipated for sequencing in the near future, providing an important tool for annotation of centromeres.

  16. Centromeres Off the Hook: Massive Changes in Centromere Size and Structure Following Duplication of CenH3 Gene in Fabeae Species

    Czech Academy of Sciences Publication Activity Database

    Neumann, Pavel; Pavlíková, Zuzana; Koblížková, Andrea; Vrbová, Iva; Jedličková, Veronika; Novák, Petr; Macas, Jiří

    2015-01-01

    Roč. 32, č. 7 (2015), s. 1862-1879 ISSN 0737-4038 R&D Projects: GA ČR(CZ) GAP501/11/1843; GA MŠk(CZ) LH11058 Institutional support: RVO:60077344 Keywords : Centromere * CenH3 * centromere drive * chromosome Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 13.649, year: 2015

  17. Epigenetically-inherited centromere and neocentromere DNA replicates earliest in S-phase.

    Directory of Open Access Journals (Sweden)

    Amnon Koren

    2010-08-01

    Full Text Available Eukaryotic centromeres are maintained at specific chromosomal sites over many generations. In the budding yeast Saccharomyces cerevisiae, centromeres are genetic elements defined by a DNA sequence that is both necessary and sufficient for function; whereas, in most other eukaryotes, centromeres are maintained by poorly characterized epigenetic mechanisms in which DNA has a less definitive role. Here we use the pathogenic yeast Candida albicans as a model organism to study the DNA replication properties of centromeric DNA. By determining the genome-wide replication timing program of the C. albicans genome, we discovered that each centromere is associated with a replication origin that is the first to fire on its respective chromosome. Importantly, epigenetic formation of new ectopic centromeres (neocentromeres was accompanied by shifts in replication timing, such that a neocentromere became the first to replicate and became associated with origin recognition complex (ORC components. Furthermore, changing the level of the centromere-specific histone H3 isoform led to a concomitant change in levels of ORC association with centromere regions, further supporting the idea that centromere proteins determine origin activity. Finally, analysis of centromere-associated DNA revealed a replication-dependent sequence pattern characteristic of constitutively active replication origins. This strand-biased pattern is conserved, together with centromere position, among related strains and species, in a manner independent of primary DNA sequence. Thus, inheritance of centromere position is correlated with a constitutively active origin of replication that fires at a distinct early time. We suggest a model in which the distinct timing of DNA replication serves as an epigenetic mechanism for the inheritance of centromere position.

  18. Abnormal centromere-chromatid apposition (ACCA) and Peters' anomaly.

    Science.gov (United States)

    Wertelecki, W; Dev, V G; Superneau, D W

    1985-08-01

    Abnormal centromere-chromatid apposition (ACCA) was noted in a patient with Peters' anomaly. Previous reports of ACCA emphasized its association with tetraphocomelia and other congenital malformations (Roberts, SC Phocomelia, Pseudothalidomide Syndromes). This report expands the array of congenital malformations associated with ACCA and emphasizes the diagnostic importance of ocular defects for the ascertainment of additional cases of ACCA and its possible relationship with abnormal cell division.

  19. Phylogenetic and structural analysis of centromeric DNA and kinetochore proteins

    OpenAIRE

    Meraldi, Patrick; McAinsh, Andrew D; Rheinbay, Esther; Sorger, Peter K

    2006-01-01

    Background: Kinetochores are large multi-protein structures that assemble on centromeric DNA (CEN DNA) and mediate the binding of chromosomes to microtubules. Comprising 125 base-pairs of CEN DNA and 70 or more protein components, Saccharomyces cerevisiae kinetochores are among the best understood. In contrast, most fungal, plant and animal cells assemble kinetochores on CENs that are longer and more complex, raising the question of whether kinetochore architecture has been conserved through ...

  20. Conservation of the Centromere/Kinetochore Protein ZW10

    OpenAIRE

    Starr, Daniel A.; Williams, Byron C.; Li, Zexiao; Etemad-Moghadam, Bijan; Dawe, R. Kelly; Goldberg, Michael L.

    1997-01-01

    Mutations in the essential Drosophila melanogaster gene zw10 disrupt chromosome segregation, producing chromosomes that lag at the metaphase plate during anaphase of mitosis and both meiotic divisions. Recent evidence suggests that the product of this gene, DmZW10, acts at the kinetochore as part of a tension-sensing checkpoint at anaphase onset. DmZW10 displays an intriguing cell cycle–dependent intracellular distribution, apparently moving from the centromere/kinetochore at prometaphase to ...

  1. Identification of the centromeric repeat in the threespine stickleback fish (Gasterosteus aculeatus).

    Science.gov (United States)

    Cech, Jennifer N; Peichel, Catherine L

    2015-12-01

    Centromere sequences exist as gaps in many genome assemblies due to their repetitive nature. Here we take an unbiased approach utilizing centromere protein A (CENP-A) chomatin immunoprecipitation followed by high-throughput sequencing to identify the centromeric repeat sequence in the threespine stickleback fish (Gasterosteus aculeatus). A 186-bp, AT-rich repeat was validated as centromeric using both fluorescence in situ hybridization (FISH) and immunofluorescence combined with FISH (IF-FISH) on interphase nuclei and metaphase spreads. This repeat hybridizes strongly to the centromere on all chromosomes, with the exception of weak hybridization to the Y chromosome. Together, our work provides the first validated sequence information for the threespine stickleback centromere.

  2. Restructuring of Holocentric Centromeres During Meiosis in the Plant Rhynchospora pubera.

    Science.gov (United States)

    Marques, André; Schubert, Veit; Houben, Andreas; Pedrosa-Harand, Andrea

    2016-10-01

    Centromeres are responsible for the correct segregation of chromosomes during mitosis and meiosis. Holocentric chromosomes, characterized by multiple centromere units along each chromatid, have particular adaptations to ensure regular disjunction during meiosis. Here we show by detecting CENH3, CENP-C, tubulin, and centromeric repeats that holocentromeres may be organized differently in mitosis and meiosis of Rhynchospora pubera Contrasting to the mitotic linear holocentromere organization, meiotic centromeres show several clusters of centromere units (cluster-holocentromeres) during meiosis I. They accumulate along the poleward surface of bivalents where spindle fibers perpendicularly attach. During meiosis II, the cluster-holocentromeres are mostly present in the midregion of each chromatid. A linear holocentromere organization is restored after meiosis during pollen mitosis. Thus, a not yet described case of a cluster-holocentromere organization, showing a clear centromere restructuration between mitosis and meiosis, was identified in a holocentric organism. Copyright © 2016 by the Genetics Society of America.

  3. Neocentromeres Provide Chromosome Segregation Accuracy and Centromere Clustering to Multiple Loci along a Candida albicans Chromosome.

    Directory of Open Access Journals (Sweden)

    Laura S Burrack

    2016-09-01

    Full Text Available Assembly of kinetochore complexes, involving greater than one hundred proteins, is essential for chromosome segregation and genome stability. Neocentromeres, or new centromeres, occur when kinetochores assemble de novo, at DNA loci not previously associated with kinetochore proteins, and they restore chromosome segregation to chromosomes lacking a functional centromere. Neocentromeres have been observed in a number of diseases and may play an evolutionary role in adaptation or speciation. However, the consequences of neocentromere formation on chromosome missegregation rates, gene expression, and three-dimensional (3D nuclear structure are not well understood. Here, we used Candida albicans, an organism with small, epigenetically-inherited centromeres, as a model system to study the functions of twenty different neocentromere loci along a single chromosome, chromosome 5. Comparison of neocentromere properties relative to native centromere functions revealed that all twenty neocentromeres mediated chromosome segregation, albeit to different degrees. Some neocentromeres also caused reduced levels of transcription from genes found within the neocentromere region. Furthermore, like native centromeres, neocentromeres clustered in 3D with active/functional centromeres, indicating that formation of a new centromere mediates the reorganization of 3D nuclear architecture. This demonstrates that centromere clustering depends on epigenetically defined function and not on the primary DNA sequence, and that neocentromere function is independent of its distance from the native centromere position. Together, the results show that a neocentromere can form at many loci along a chromosome and can support the assembly of a functional kinetochore that exhibits native centromere functions including chromosome segregation accuracy and centromere clustering within the nucleus.

  4. Chromosome segregation regulation in human zygotes : Altered mitotic histone phosphorylation dynamics underlying centromeric targeting of the chromosomal passenger complex

    NARCIS (Netherlands)

    Van De Werken, C.; Avo Santos, M.; Laven, J. S E; Eleveld, C.; Fauser, B. C J M; Lens, S. M A; Baart, E. B.

    2015-01-01

    STUDY QUESTION Are the kinase feedback loops that regulate activation and centromeric targeting of the chromosomal passenger complex (CPC), functional during mitosis in human embryos? SUMMARY ANSWER Investigation of the regulatory kinase pathways involved in centromeric CPC targeting revealed normal

  5. Plasmodium falciparum centromeres display a unique epigenetic makeup and cluster prior to and during schizogony.

    Science.gov (United States)

    Hoeijmakers, Wieteke A M; Flueck, Christian; Françoijs, Kees-Jan; Smits, Arne H; Wetzel, Johanna; Volz, Jennifer C; Cowman, Alan F; Voss, Till; Stunnenberg, Hendrik G; Bártfai, Richárd

    2012-09-01

    Centromeres are essential for the faithful transmission of chromosomes to the next generation, therefore being essential in all eukaryotic organisms. The centromeres of Plasmodium falciparum, the causative agent of the most severe form of malaria, have been broadly mapped on most chromosomes, but their epigenetic composition remained undefined. Here, we reveal that the centromeric histone variant PfCENH3 occupies a 4-4.5 kb region on each P. falciparum chromosome, which is devoid of pericentric heterochromatin but harbours another histone variant, PfH2A.Z. These CENH3 covered regions pinpoint the exact position of the centromere on all chromosomes and revealed that all centromeric regions have similar size and sequence composition. Immunofluorescence assay of PfCENH3 strongly suggests that P. falciparum centromeres cluster to a single nuclear location prior to and during mitosis and cytokinesis but dissociate soon after invasion. In summary, we reveal a dynamic association of Plasmodium centromeres, which bear a unique epigenetic signature and conform to a strict structure. These findings suggest that DNA-associated and epigenetic elements play an important role in centromere establishment in this important human pathogen. © 2012 Blackwell Publishing Ltd.

  6. Human Artificial Chromosomes with Alpha Satellite-Based De Novo Centromeres Show Increased Frequency of Nondisjunction and Anaphase Lag

    OpenAIRE

    Rudd, M. Katharine; Mays, Robert W.; Schwartz, Stuart; Willard, Huntington F.

    2003-01-01

    Human artificial chromosomes have been used to model requirements for human chromosome segregation and to explore the nature of sequences competent for centromere function. Normal human centromeres require specialized chromatin that consists of alpha satellite DNA complexed with epigenetically modified histones and centromere-specific proteins. While several types of alpha satellite DNA have been used to assemble de novo centromeres in artificial chromosome assays, the extent to which they fu...

  7. The rapidly evolving centromere-specific histone has stringent functional requirements in Arabidopsis thaliana.

    Science.gov (United States)

    Ravi, Maruthachalam; Kwong, Pak N; Menorca, Ron M G; Valencia, Joel T; Ramahi, Joseph S; Stewart, Jodi L; Tran, Robert K; Sundaresan, Venkatesan; Comai, Luca; Chan, Simon W-L

    2010-10-01

    Centromeres control chromosome inheritance in eukaryotes, yet their DNA structure and primary sequence are hypervariable. Most animals and plants have megabases of tandem repeats at their centromeres, unlike yeast with unique centromere sequences. Centromere function requires the centromere-specific histone CENH3 (CENP-A in human), which replaces histone H3 in centromeric nucleosomes. CENH3 evolves rapidly, particularly in its N-terminal tail domain. A portion of the CENH3 histone-fold domain, the CENP-A targeting domain (CATD), has been previously shown to confer kinetochore localization and centromere function when swapped into human H3. Furthermore, CENP-A in human cells can be functionally replaced by CENH3 from distantly related organisms including Saccharomyces cerevisiae. We have used cenh3-1 (a null mutant in Arabidopsis thaliana) to replace endogenous CENH3 with GFP-tagged variants. A H3.3 tail domain-CENH3 histone-fold domain chimera rescued viability of cenh3-1, but CENH3's lacking a tail domain were nonfunctional. In contrast to human results, H3 containing the A. thaliana CATD cannot complement cenh3-1. GFP-CENH3 from the sister species A. arenosa functionally replaces A. thaliana CENH3. GFP-CENH3 from the close relative Brassica rapa was targeted to centromeres, but did not complement cenh3-1, indicating that kinetochore localization and centromere function can be uncoupled. We conclude that CENH3 function in A. thaliana, an organism with large tandem repeat centromeres, has stringent requirements for functional complementation in mitosis.

  8. Image simulation using LOCUS

    International Nuclear Information System (INIS)

    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. Meiotic Studies on Combinations of Chromosomes With Different Sized Centromeres in Maize

    Directory of Open Access Journals (Sweden)

    Fangpu Han

    2018-06-01

    Full Text Available Multiple centromere misdivision derivatives of a translocation between the supernumerary B chromosome and the short arm of chromosome 9 (TB-9Sb permit investigation of how centromeres of different sizes behave in meiosis in opposition or in competition with each other. In the first analysis, heterozygotes were produced between the normal TB-9Sb and derivatives of it that resulted from centromere misdivision that reduced the amounts of centromeric DNA. These heterozygotes could test whether these drastic differences would result in meiotic drive of the larger chromosome in female meiosis. Cytological determinations of the segregation of large and small centromeres among thousands of progeny of four combinations were made. The recovery of the larger centromere was at a few percent higher frequency in two of four combinations. However, examination of phosphorylated histone H2A-Thr133, a characteristic of active centromeres, showed a lack of correlation with the size of the centromeric DNA, suggesting an expansion of the basal protein features of the kinetochore in two of the three cases despite the reduction in the size of the underlying DNA. In the second analysis, plants containing different sizes of the B chromosome centromere were crossed to plants with TB-9Sb with a foldback duplication of 9S (TB-9Sb-Dp9. In the progeny, plants containing large and small versions of the B chromosome centromere were selected by FISH. A meiotic “tug of war” occurred in hybrid combinations by recombination between the normal 9S and the foldback duplication in those cases in which pairing occurred. Such pairing and recombination produce anaphase I bridges but in some cases the large and small centromeres progressed to the same pole. In one combination, new dicentric chromosomes were found in the progeny. Collectively, the results indicate that the size of the underlying DNA of a centromere does not dramatically affect its segregation properties or its ability

  10. Widespread Positive Selection Drives Differentiation of Centromeric Proteins in the Drosophila melanogaster subgroup.

    Science.gov (United States)

    Beck, Emily A; Llopart, Ana

    2015-11-25

    Rapid evolution of centromeric satellite repeats is thought to cause compensatory amino acid evolution in interacting centromere-associated kinetochore proteins. Cid, a protein that mediates kinetochore/centromere interactions, displays particularly high amino acid turnover. Rapid evolution of both Cid and centromeric satellite repeats led us to hypothesize that the apparent compensatory evolution may extend to interacting partners in the Condensin I complex (i.e., SMC2, SMC4, Cap-H, Cap-D2, and Cap-G) and HP1s. Missense mutations in these proteins often result in improper centromere formation and aberrant chromosome segregation, thus selection for maintained function and coevolution among proteins of the complex is likely strong. Here, we report evidence of rapid evolution and recurrent positive selection in seven centromere-associated proteins in species of the Drosophila melanogaster subgroup, and further postulate that positive selection on these proteins could be a result of centromere drive and compensatory changes, with kinetochore proteins competing for optimal spindle attachment.

  11. High quality maize centromere 10 sequence reveals evidence of frequent recombination events

    Directory of Open Access Journals (Sweden)

    Thomas Kai Wolfgruber

    2016-03-01

    Full Text Available The ancestral centromeres of maize contain long stretches of the tandemly arranged CentC repeat. The abundance of tandem DNA repeats and centromeric retrotransposons (CR have presented a significant challenge to completely assembling centromeres using traditional sequencing methods. Here we report a nearly complete assembly of the 1.85 Mb maize centromere 10 from inbred B73 using PacBio technology and BACs from the reference genome project. The error rates estimated from overlapping BAC sequences are 7 x 10-6 and 5 x 10-5 for mismatches and indels, respectively. The number of gaps in the region covered by the reassembly was reduced from 140 in the reference genome to three. Three expressed genes are located between 92 and 477 kb of the inferred ancestral CentC cluster, which lies within the region of highest centromeric repeat density. The improved assembly increased the count of full-length centromeric retrotransposons from 5 to 55 and revealed a 22.7 kb segmental duplication that occurred approximately 121,000 years ago. Our analysis provides evidence of frequent recombination events in the form of partial retrotransposons, deletions within retrotransposons, chimeric retrotransposons, segmental duplications including higher order CentC repeats, a deleted CentC monomer, centromere-proximal inversions, and insertion of mitochondrial sequences. Double-strand DNA break (DSB repair is the most plausible mechanism for these events and may be the major driver of centromere repeat evolution and diversity. This repair appears to be mediated by microhomology, suggesting that tandem repeats may have evolved to facilitate the repair of frequent DSBs in centromeres.

  12. Rad51-Rad52 mediated maintenance of centromeric chromatin in Candida albicans.

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    Sreyoshi Mitra

    2014-04-01

    Full Text Available Specification of the centromere location in most eukaryotes is not solely dependent on the DNA sequence. However, the non-genetic determinants of centromere identity are not clearly defined. While multiple mechanisms, individually or in concert, may specify centromeres epigenetically, most studies in this area are focused on a universal factor, a centromere-specific histone H3 variant CENP-A, often considered as the epigenetic determinant of centromere identity. In spite of variable timing of its loading at centromeres across species, a replication coupled early S phase deposition of CENP-A is found in most yeast centromeres. Centromeres are the earliest replicating chromosomal regions in a pathogenic budding yeast Candida albicans. Using a 2-dimensional agarose gel electrophoresis assay, we identify replication origins (ORI7-LI and ORI7-RI proximal to an early replicating centromere (CEN7 in C. albicans. We show that the replication forks stall at CEN7 in a kinetochore dependent manner and fork stalling is reduced in the absence of the homologous recombination (HR proteins Rad51 and Rad52. Deletion of ORI7-RI causes a significant reduction in the stalled fork signal and an increased loss rate of the altered chromosome 7. The HR proteins, Rad51 and Rad52, have been shown to play a role in fork restart. Confocal microscopy shows declustered kinetochores in rad51 and rad52 mutants, which are evidence of kinetochore disintegrity. CENP-ACaCse4 levels at centromeres, as determined by chromatin immunoprecipitation (ChIP experiments, are reduced in absence of Rad51/Rad52 resulting in disruption of the kinetochore structure. Moreover, western blot analysis reveals that delocalized CENP-A molecules in HR mutants degrade in a similar fashion as in other kinetochore mutants described before. Finally, co-immunoprecipitation assays indicate that Rad51 and Rad52 physically interact with CENP-ACaCse4 in vivo. Thus, the HR proteins Rad51 and Rad52

  13. Endogenous Locus Reporter Assays.

    Science.gov (United States)

    Liu, Yaping; Hermes, Jeffrey; Li, Jing; Tudor, Matthew

    2018-01-01

    Reporter gene assays are widely used in high-throughput screening (HTS) to identify compounds that modulate gene expression. Traditionally a reporter gene assay is built by cloning an endogenous promoter sequence or synthetic response elements in the regulatory region of a reporter gene to monitor transcriptional activity of a specific biological process (exogenous reporter assay). In contrast, an endogenous locus reporter has a reporter gene inserted in the endogenous gene locus that allows the reporter gene to be expressed under the control of the same regulatory elements as the endogenous gene, thus more accurately reflecting the changes seen in the regulation of the actual gene. In this chapter, we introduce some of the considerations behind building a reporter gene assay for high-throughput compound screening and describe the methods we have utilized to establish 1536-well format endogenous locus reporter and exogenous reporter assays for the screening of compounds that modulate Myc pathway activity.

  14. Mislocalization of the Drosophila centromere-specific histone CIDpromotes formation of functional ectopic kinetochores

    Energy Technology Data Exchange (ETDEWEB)

    Heun, Patrick; Erhardt, Sylvia; Blower, Michael D.; Weiss,Samara; Skora, Andrew D.; Karpen, Gary H.

    2006-01-30

    The centromere-specific histone variant CENP-A (CID in Drosophila) is a structural and functional foundation for kinetochore formation and chromosome segregation. Here, we show that overexpressed CID is mislocalized into normally non-centromeric regions in Drosophila tissue culture cells and animals. Analysis of mitoses in living and fixed cells reveals that mitotic delays, anaphase bridges, chromosome fragmentation, and cell and organismal lethality are all direct consequences of CID mislocalization. In addition, proteins that are normally restricted to endogenous kinetochores assemble at a subset of ectopic CID incorporation regions. The presence of microtubule motors and binding proteins, spindle attachments, and aberrant chromosome morphologies demonstrate that these ectopic kinetochores are functional. We conclude that CID mislocalization promotes formation of ectopic centromeres and multicentric chromosomes, which causes chromosome missegregation, aneuploidy, and growth defects. Thus, CENP-A mislocalization is one possible mechanism for genome instability during cancer progression, as well as centromere plasticity during evolution.

  15. Clinical spectrum of immunodeficiency, centromeric instability and facial dysmorphism (ICF syndrome).

    NARCIS (Netherlands)

    Hagleitner, M.M.; Lankester, A.; Maraschio, P.; Hulten, M.; Fryns, J.P.; Schuetz, C.; Gimelli, G.; Davies, E.G.; Gennery, A.R.; Belohradsky, B.H.; Groot, R. de; Gerritsen, E.J.; Mattina, T.; Howard, P.J.; Fasth, A.; Reisli, I.; Furthner, D.; Slatter, M.A.; Cant, A.J.; Cazzola, G.; Dijken, P.J. van; Deuren, M. van; Greef, J.C. de; Maarel, S.M. van der; Weemaes, C.M.R.

    2008-01-01

    BACKGROUND: Immunodeficiency, centromeric instability and facial dysmorphism (ICF syndrome) is a rare autosomal recessive disease characterised by facial dysmorphism, immunoglobulin deficiency and branching of chromosomes 1, 9 and 16 after PHA stimulation of lymphocytes. Hypomethylation of DNA of a

  16. The IGF2 Locus

    Science.gov (United States)

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

  17. Premitotic assembly of human CENPs -T and -W switches centromeric chromatin to a mitotic state.

    Directory of Open Access Journals (Sweden)

    Lisa Prendergast

    2011-06-01

    Full Text Available Centromeres are differentiated chromatin domains, present once per chromosome, that direct segregation of the genome in mitosis and meiosis by specifying assembly of the kinetochore. They are distinct genetic loci in that their identity in most organisms is determined not by the DNA sequences they are associated with, but through specific chromatin composition and context. The core nucleosomal protein CENP-A/cenH3 plays a primary role in centromere determination in all species and directs assembly of a large complex of associated proteins in vertebrates. While CENP-A itself is stably transmitted from one generation to the next, the nature of the template for centromere replication and its relationship to kinetochore function are as yet poorly understood. Here, we investigate the assembly and inheritance of a histone fold complex of the centromere, the CENP-T/W complex, which is integrated with centromeric chromatin in association with canonical histone H3 nucleosomes. We have investigated the cell cycle regulation, timing of assembly, generational persistence, and requirement for function of CENPs -T and -W in the cell cycle in human cells. The CENP-T/W complex assembles through a dynamic exchange mechanism in late S-phase and G2, is required for mitosis in each cell cycle and does not persist across cell generations, properties reciprocal to those measured for CENP-A. We propose that the CENP-A and H3-CENP-T/W nucleosome components of the centromere are specialized for centromeric and kinetochore activities, respectively. Segregation of the assembly mechanisms for the two allows the cell to switch between chromatin configurations that reciprocally support the replication of the centromere and its conversion to a mitotic state on postreplicative chromatin.

  18. Centromere Locations in Brassica A and C Genomes Revealed Through Half-Tetrad Analysis.

    Science.gov (United States)

    Mason, Annaliese S; Rousseau-Gueutin, Mathieu; Morice, Jérôme; Bayer, Philipp E; Besharat, Naghmeh; Cousin, Anouska; Pradhan, Aneeta; Parkin, Isobel A P; Chèvre, Anne-Marie; Batley, Jacqueline; Nelson, Matthew N

    2016-02-01

    Locating centromeres on genome sequences can be challenging. The high density of repetitive elements in these regions makes sequence assembly problematic, especially when using short-read sequencing technologies. It can also be difficult to distinguish between active and recently extinct centromeres through sequence analysis. An effective solution is to identify genetically active centromeres (functional in meiosis) by half-tetrad analysis. This genetic approach involves detecting heterozygosity along chromosomes in segregating populations derived from gametes (half-tetrads). Unreduced gametes produced by first division restitution mechanisms comprise complete sets of nonsister chromatids. Along these chromatids, heterozygosity is maximal at the centromeres, and homologous recombination events result in homozygosity toward the telomeres. We genotyped populations of half-tetrad-derived individuals (from Brassica interspecific hybrids) using a high-density array of physically anchored SNP markers (Illumina Brassica 60K Infinium array). Mapping the distribution of heterozygosity in these half-tetrad individuals allowed the genetic mapping of all 19 centromeres of the Brassica A and C genomes to the reference Brassica napus genome. Gene and transposable element density across the B. napus genome were also assessed and corresponded well to previously reported genetic map positions. Known centromere-specific sequences were located in the reference genome, but mostly matched unanchored sequences, suggesting that the core centromeric regions may not yet be assembled into the pseudochromosomes of the reference genome. The increasing availability of genetic markers physically anchored to reference genomes greatly simplifies the genetic and physical mapping of centromeres using half-tetrad analysis. We discuss possible applications of this approach, including in species where half-tetrads are currently difficult to isolate. Copyright © 2016 by the Genetics Society of America.

  19. Centromere and telomere sequence alterations reflect the rapid genome evolution within the carnivorous plant genus Genlisea

    Czech Academy of Sciences Publication Activity Database

    Tran, T.D.; Cao, H.X.; Jovtchev, G.; Neumann, Pavel; Novák, Petr; Fojtová, M.; Vu, G.T.H.; Macas, Jiří; Fajkus, Jiří; Schubert, I.; Fuchs, J.

    2015-01-01

    Roč. 84, č. 6 (2015), s. 1087-1099 ISSN 0960-7412 R&D Projects: GA ČR GBP501/12/G090; GA ČR GA13-06943S Institutional support: RVO:60077344 ; RVO:68081707 Keywords : Centromeric tandem repeat * centromeric retrotransposons * Genlisea nigrocaulis, hispidula Subject RIV: EB - Genetics ; Molecular Biology; BO - Biophysics (BFU-R) Impact factor: 5.468, year: 2015

  20. Functional Identification of the Plasmodium Centromere and Generation of a Plasmodium Artificial Chromosome

    OpenAIRE

    Iwanaga, Shiroh; Khan, Shahid M.; Kaneko, Izumi; Christodoulou, Zoe; Newbold, Chris; Yuda, Masao; Janse, Chris J.; Waters, Andrew P.

    2010-01-01

    Summary The artificial chromosome represents a useful tool for gene transfer, both as cloning vectors and in chromosome biology research. To generate a Plasmodium artificial chromosome (PAC), we had to first functionally identify and characterize the parasite's centromere. A putative centromere (pbcen5) was cloned from chromosome 5 of the rodent parasite P. berghei based on a Plasmodium gene-synteny map. Plasmids containing pbcen5 were stably maintained in parasites during a blood-stage infec...

  1. Analysis of ParB-centromere interactions by multiplex SPR imaging reveals specific patterns for binding ParB in six centromeres of Burkholderiales chromosomes and plasmids.

    Directory of Open Access Journals (Sweden)

    Flavien Pillet

    Full Text Available Bacterial centromeres-also called parS, are cis-acting DNA sequences which, together with the proteins ParA and ParB, are involved in the segregation of chromosomes and plasmids. The specific binding of ParB to parS nucleates the assembly of a large ParB/DNA complex from which ParA-the motor protein, segregates the sister replicons. Closely related families of partition systems, called Bsr, were identified on the chromosomes and large plasmids of the multi-chromosomal bacterium Burkholderia cenocepacia and other species from the order Burkholeriales. The centromeres of the Bsr partition families are 16 bp palindromes, displaying similar base compositions, notably a central CG dinucleotide. Despite centromeres bind the cognate ParB with a narrow specificity, weak ParB-parS non cognate interactions were nevertheless detected between few Bsr partition systems of replicons not belonging to the same genome. These observations suggested that Bsr partition systems could have a common ancestry but that evolution mostly erased the possibilities of cross-reactions between them, in particular to prevent replicon incompatibility. To detect novel similarities between Bsr partition systems, we have analyzed the binding of six Bsr parS sequences and a wide collection of modified derivatives, to their cognate ParB. The study was carried out by Surface Plasmon Resonance imaging (SPRi mulitplex analysis enabling a systematic survey of each nucleotide position within the centromere. We found that in each parS some positions could be changed while maintaining binding to ParB. Each centromere displays its own pattern of changes, but some positions are shared more or less widely. In addition from these changes we could speculate evolutionary links between these centromeres.

  2. Analysis of ParB-centromere interactions by multiplex SPR imaging reveals specific patterns for binding ParB in six centromeres of Burkholderiales chromosomes and plasmids.

    Science.gov (United States)

    Pillet, Flavien; Passot, Fanny Marie; Pasta, Franck; Anton Leberre, Véronique; Bouet, Jean-Yves

    2017-01-01

    Bacterial centromeres-also called parS, are cis-acting DNA sequences which, together with the proteins ParA and ParB, are involved in the segregation of chromosomes and plasmids. The specific binding of ParB to parS nucleates the assembly of a large ParB/DNA complex from which ParA-the motor protein, segregates the sister replicons. Closely related families of partition systems, called Bsr, were identified on the chromosomes and large plasmids of the multi-chromosomal bacterium Burkholderia cenocepacia and other species from the order Burkholeriales. The centromeres of the Bsr partition families are 16 bp palindromes, displaying similar base compositions, notably a central CG dinucleotide. Despite centromeres bind the cognate ParB with a narrow specificity, weak ParB-parS non cognate interactions were nevertheless detected between few Bsr partition systems of replicons not belonging to the same genome. These observations suggested that Bsr partition systems could have a common ancestry but that evolution mostly erased the possibilities of cross-reactions between them, in particular to prevent replicon incompatibility. To detect novel similarities between Bsr partition systems, we have analyzed the binding of six Bsr parS sequences and a wide collection of modified derivatives, to their cognate ParB. The study was carried out by Surface Plasmon Resonance imaging (SPRi) mulitplex analysis enabling a systematic survey of each nucleotide position within the centromere. We found that in each parS some positions could be changed while maintaining binding to ParB. Each centromere displays its own pattern of changes, but some positions are shared more or less widely. In addition from these changes we could speculate evolutionary links between these centromeres.

  3. Centromeric DNA replication reconstitution reveals DNA loops and ATR checkpoint suppression.

    Science.gov (United States)

    Aze, Antoine; Sannino, Vincenzo; Soffientini, Paolo; Bachi, Angela; Costanzo, Vincenzo

    2016-06-01

    Half of the human genome is made up of repetitive DNA. However, mechanisms underlying replication of chromosome regions containing repetitive DNA are poorly understood. We reconstituted replication of defined human chromosome segments using bacterial artificial chromosomes in Xenopus laevis egg extract. Using this approach we characterized the chromatin assembly and replication dynamics of centromeric alpha-satellite DNA. Proteomic analysis of centromeric chromatin revealed replication-dependent enrichment of a network of DNA repair factors including the MSH2-6 complex, which was required for efficient centromeric DNA replication. However, contrary to expectations, the ATR-dependent checkpoint monitoring DNA replication fork arrest could not be activated on highly repetitive DNA due to the inability of the single-stranded DNA binding protein RPA to accumulate on chromatin. Electron microscopy of centromeric DNA and supercoil mapping revealed the presence of topoisomerase I-dependent DNA loops embedded in a protein matrix enriched for SMC2-4 proteins. This arrangement suppressed ATR signalling by preventing RPA hyper-loading, facilitating replication of centromeric DNA. These findings have important implications for our understanding of repetitive DNA metabolism and centromere organization under normal and stressful conditions.

  4. Telomere-Centromere-Driven Genomic Instability Contributes to Karyotype Evolution in a Mouse Model of Melanoma

    Directory of Open Access Journals (Sweden)

    Amanda Gonçalves dos Santos Silva

    2010-01-01

    Full Text Available Aneuploidy and chromosomal instability (CIN are hallmarks of most solid tumors. These alterations may result from inaccurate chromosomal segregation during mitosis, which can occur through several mechanisms including defective telomere metabolism, centrosome amplification, dysfunctional centromeres, and/or defective spindle checkpoint control. In this work, we used an in vitro murine melanoma model that uses a cellular adhesion blockade as a transforming factor to characterize telomeric and centromeric alterations that accompany melanocyte transformation. To study the timing of the occurrence of telomere shortening in this transformation model, we analyzed the profile of telomere length by quantitative fluorescent in situ hybridization and found that telomere length significantly decreased as additional rounds of cell adhesion blockages were performed. Together with it, an increase in telomere-free ends and complex karyotypic aberrations were also found, which include Robertsonian fusions in 100% of metaphases of the metastatic melanoma cells. These findings are in agreement with the idea that telomere length abnormalities seem to be one of the earliest genetic alterations acquired in the multistep process of malignant transformation and that telomere abnormalities result in telomere aggregation, breakage-bridge-fusion cycles, and CIN. Another remarkable feature of this model is the abundance of centromeric instability manifested as centromere fragments and centromeric fusions. Taken together, our results illustrate for this melanoma model CIN with a structural signature of centromere breakage and telomeric loss.

  5. Recurrent Gene Duplication Leads to Diverse Repertoires of Centromeric Histones in Drosophila Species.

    Science.gov (United States)

    Kursel, Lisa E; Malik, Harmit S

    2017-06-01

    Despite their essential role in the process of chromosome segregation in most eukaryotes, centromeric histones show remarkable evolutionary lability. Not only have they been lost in multiple insect lineages, but they have also undergone gene duplication in multiple plant lineages. Based on detailed study of a handful of model organisms including Drosophila melanogaster, centromeric histone duplication is considered to be rare in animals. Using a detailed phylogenomic study, we find that Cid, the centromeric histone gene, has undergone at least four independent gene duplications during Drosophila evolution. We find duplicate Cid genes in D. eugracilis (Cid2), in the montium species subgroup (Cid3, Cid4) and in the entire Drosophila subgenus (Cid5). We show that Cid3, Cid4, and Cid5 all localize to centromeres in their respective species. Some Cid duplicates are primarily expressed in the male germline. With rare exceptions, Cid duplicates have been strictly retained after birth, suggesting that they perform nonredundant centromeric functions, independent from the ancestral Cid. Indeed, each duplicate encodes a distinct N-terminal tail, which may provide the basis for distinct protein-protein interactions. Finally, we show some Cid duplicates evolve under positive selection whereas others do not. Taken together, our results support the hypothesis that Drosophila Cid duplicates have subfunctionalized. Thus, these gene duplications provide an unprecedented opportunity to dissect the multiple roles of centromeric histones. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  6. Cis-Acting Determinants Affecting Centromere Function, Sister-Chromatid Cohesion and Reciprocal Recombination during Meiosis in Saccharomyces Cerevisiae

    OpenAIRE

    Sears, D. D.; Hegemann, J. H.; Shero, J. H.; Hieter, P.

    1995-01-01

    We have employed a system that utilizes homologous pairs of human DNA-derived yeast artificial chromosomes (YACs) as marker chromosomes to assess the specific role (s) of conserved centromere DNA elements (CDEI, CDEII and CDEIII) in meiotic chromosome disjunction fidelity. Thirteen different centromere (CEN) mutations were tested for their effects on meiotic centromere function. YACs containing a wild-type CEN DNA sequence segregate with high fidelity in meiosis I (99% normal segregation) and...

  7. Boom-Bust Turnovers of Megabase-Sized Centromeric DNA in Solanum Species: Rapid Evolution of DNA Sequences Associated with Centromeres

    Czech Academy of Sciences Publication Activity Database

    Zhang, H.Q.; Koblížková, Andrea; Wang, K.; Gong, Z.Y.; Oliveira, L.; Torres, G.A.; Wu, Y.; Zhang, W.; Novák, Petr; Buell, C.R.; Macas, Jiří; Jiang, J.

    2014-01-01

    Roč. 26, č. 4 (2014), s. 1436-1447 ISSN 1040-4651 Institutional support: RVO:60077344 Keywords : Alpha-satellite DNA * repetitive sequences * rice centromeres Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 9.338, year: 2014

  8. Differential Regulation of Strand-Specific Transcripts from Arabidopsis Centromeric Satellite Repeats.

    Directory of Open Access Journals (Sweden)

    2005-12-01

    Full Text Available Centromeres interact with the spindle apparatus to enable chromosome disjunction and typically contain thousands of tandemly arranged satellite repeats interspersed with retrotransposons. While their role has been obscure, centromeric repeats are epigenetically modified and centromere specification has a strong epigenetic component. In the yeast Schizosaccharomyces pombe, long heterochromatic repeats are transcribed and contribute to centromere function via RNA interference (RNAi. In the higher plant Arabidopsis thaliana, as in mammalian cells, centromeric satellite repeats are short (180 base pairs, are found in thousands of tandem copies, and are methylated. We have found transcripts from both strands of canonical, bulk Arabidopsis repeats. At least one subfamily of 180-base pair repeats is transcribed from only one strand and regulated by RNAi and histone modification. A second subfamily of repeats is also silenced, but silencing is lost on both strands in mutants in the CpG DNA methyltransferase MET1, the histone deacetylase HDA6/SIL1, or the chromatin remodeling ATPase DDM1. This regulation is due to transcription from Athila2 retrotransposons, which integrate in both orientations relative to the repeats, and differs between strains of Arabidopsis. Silencing lost in met1 or hda6 is reestablished in backcrosses to wild-type, but silencing lost in RNAi mutants and ddm1 is not. Twenty-four-nucleotide small interfering RNAs from centromeric repeats are retained in met1 and hda6, but not in ddm1, and may have a role in this epigenetic inheritance. Histone H3 lysine-9 dimethylation is associated with both classes of repeats. We propose roles for transcribed repeats in the epigenetic inheritance and evolution of centromeres.

  9. Centromere separation and association in the nuclei of an interspecific hybrid between Torenia fournieri and T. baillonii (Scrophulariaceae) during mitosis and meiosis.

    Science.gov (United States)

    Kikuchi, Shinji; Tanaka, Hiroyuki; Wako, Toshiyuki; Tsujimoto, Hisashi

    2007-10-01

    In the nuclei of some interspecific hybrid and allopolyploid plant species, each genome occupies a separate spatial domain. To analyze this phenomenon, we studied localization of the centromeres in the nuclei of a hybrid between Torenia fournieri and T. baillonii during mitosis and meiosis using three-dimensional fluorescence in situ hybridization (3D-FISH) probed with species-specific centromere repeats. Centromeres of each genome were located separately in undifferentiated cells but not differentiated cells, suggesting that cell division might be the possible force causing centromere separation. However, no remarkable difference of dividing distance was detected between chromatids with different centromeres in anaphase and telophase, indicating that tension of the spindle fiber attached to each chromatid is not the cause of centromere separation in Torenia. In differentiated cells, centromeres in both genomes were not often observed for the expected chromosome number, indicating centromere association. In addition, association of centromeres from the same genome was observed at a higher frequency than between different genomes. This finding suggests that centromeres within one genome are spatially separated from those within the other. This close position may increase possibility of association between centromeres of the same genome. In meiotic prophase, all centromeres irrespective of the genome were associated in a certain portion of the nucleus. Since centromere association in the interspecific hybrid and amphiploid was tighter than that in the diploid parents, it is possible that this phenomenon may be involved in sorting and pairing of homologous chromosomes.

  10. Most Uv-Induced Reciprocal Translocations in SORDARIA MACROSPORA Occur in or near Centromere Regions.

    Science.gov (United States)

    Leblon, G; Zickler, D; Lebilcot, S

    1986-02-01

    In fungi, translocations can be identified and classified by the patterns of ascospore abortion in asci from crosses of rearrangement x normal sequence. Previous studies of UV-induced rearrangements in Sordaria macrospora revealed that a major class (called type III) appeared to be reciprocal translocations that were anomalous in producing an unexpected class of asci with four aborted ascospores in bbbbaaaa linear sequence (b = black; a = abortive). The present study shows that the anomalous type III rearrangements are, in fact, reciprocal translocations having both breakpoints within or adjacent to centromeres and that bbbbaaaa asci result from 3:1 disjunction from the translocation quadrivalent.-Electron microscopic observations of synaptonemal complexes enable centromeres to be visualized. Lengths of synaptonemal complexes lateral elements in translocation quadrivalents accurately reflect chromosome arm lengths, enabling breakpoints to be located reliably in centromere regions. All genetic data are consistent with the behavior expected of translocations with breakpoints at centromeres.-Two-thirds of the UV-induced reciprocal translocations are of this type. Certain centromere regions are involved preferentially. Among 73 type-III translocations, there were but 13 of the 21 possible chromosome combinations and 20 of the 42 possible combinations of chromosome arms.

  11. APC/C-Cdc20 mediates deprotection of centromeric cohesin at meiosis II in yeast.

    Science.gov (United States)

    Jonak, Katarzyna; Zagoriy, Ievgeniia; Oz, Tugce; Graf, Peter; Rojas, Julie; Mengoli, Valentina; Zachariae, Wolfgang

    2017-06-18

    Cells undergoing meiosis produce haploid gametes through one round of DNA replication followed by 2 rounds of chromosome segregation. This requires that cohesin complexes, which establish sister chromatid cohesion during S phase, are removed in a stepwise manner. At meiosis I, the separase protease triggers the segregation of homologous chromosomes by cleaving cohesin's Rec8 subunit on chromosome arms. Cohesin persists at centromeres because the PP2A phosphatase, recruited by the shugoshin protein, dephosphorylates Rec8 and thereby protects it from cleavage. While chromatids disjoin upon cleavage of centromeric Rec8 at meiosis II, it was unclear how and when centromeric Rec8 is liberated from its protector PP2A. One proposal is that bipolar spindle forces separate PP2A from Rec8 as cells enter metaphase II. We show here that sister centromere biorientation is not sufficient to "deprotect" Rec8 at meiosis II in yeast. Instead, our data suggest that the ubiquitin-ligase APC/C Cdc20 removes PP2A from centromeres by targeting for degradation the shugoshin Sgo1 and the kinase Mps1. This implies that Rec8 remains protected until entry into anaphase II when it is phosphorylated concurrently with the activation of separase. Here, we provide further support for this model and speculate on its relevance to mammalian oocytes.

  12. The Role of Dicentric Chromosome Formation and Secondary Centromere Deletion in the Evolution of Myeloid Malignancy

    Science.gov (United States)

    MacKinnon, Ruth N.; Campbell, Lynda J.

    2011-01-01

    Dicentric chromosomes have been identified as instigators of the genome instability associated with cancer, but this instability is often resolved by one of a number of different secondary events. These include centromere inactivation, inversion, and intercentromeric deletion. Deletion or excision of one of the centromeres may be a significant occurrence in myeloid malignancy and other malignancies but has not previously been widely recognized, and our reports are the first describing centromere deletion in cancer cells. We review what is known about dicentric chromosomes and the mechanisms by which they can undergo stabilization in both constitutional and cancer genomes. The failure to identify centromere deletion in cancer cells until recently can be partly explained by the standard approaches to routine diagnostic cancer genome analysis, which do not identify centromeres in the context of chromosome organization. This hitherto hidden group of primary dicentric, secondary monocentric chromosomes, together with other unrecognized dicentric chromosomes, points to a greater role for dicentric chromosomes in cancer initiation and progression than is generally acknowledged. We present a model that predicts and explains a significant role for dicentric chromosomes in the formation of unbalanced translocations in malignancy. PMID:22567363

  13. SOLO: a meiotic protein required for centromere cohesion, coorientation, and SMC1 localization in Drosophila melanogaster.

    Science.gov (United States)

    Yan, Rihui; Thomas, Sharon E; Tsai, Jui-He; Yamada, Yukihiro; McKee, Bruce D

    2010-02-08

    Sister chromatid cohesion is essential to maintain stable connections between homologues and sister chromatids during meiosis and to establish correct centromere orientation patterns on the meiosis I and II spindles. However, the meiotic cohesion apparatus in Drosophila melanogaster remains largely uncharacterized. We describe a novel protein, sisters on the loose (SOLO), which is essential for meiotic cohesion in Drosophila. In solo mutants, sister centromeres separate before prometaphase I, disrupting meiosis I centromere orientation and causing nondisjunction of both homologous and sister chromatids. Centromeric foci of the cohesin protein SMC1 are absent in solo mutants at all meiotic stages. SOLO and SMC1 colocalize to meiotic centromeres from early prophase I until anaphase II in wild-type males, but both proteins disappear prematurely at anaphase I in mutants for mei-S332, which encodes the Drosophila homologue of the cohesin protector protein shugoshin. The solo mutant phenotypes and the localization patterns of SOLO and SMC1 indicate that they function together to maintain sister chromatid cohesion in Drosophila meiosis.

  14. The Role of Dicentric Chromosome Formation and Secondary Centromere Deletion in the Evolution of Myeloid Malignancy

    Directory of Open Access Journals (Sweden)

    Ruth N. MacKinnon

    2011-01-01

    Full Text Available Dicentric chromosomes have been identified as instigators of the genome instability associated with cancer, but this instability is often resolved by one of a number of different secondary events. These include centromere inactivation, inversion, and intercentromeric deletion. Deletion or excision of one of the centromeres may be a significant occurrence in myeloid malignancy and other malignancies but has not previously been widely recognized, and our reports are the first describing centromere deletion in cancer cells. We review what is known about dicentric chromosomes and the mechanisms by which they can undergo stabilization in both constitutional and cancer genomes. The failure to identify centromere deletion in cancer cells until recently can be partly explained by the standard approaches to routine diagnostic cancer genome analysis, which do not identify centromeres in the context of chromosome organization. This hitherto hidden group of primary dicentric, secondary monocentric chromosomes, together with other unrecognized dicentric chromosomes, points to a greater role for dicentric chromosomes in cancer initiation and progression than is generally acknowledged. We present a model that predicts and explains a significant role for dicentric chromosomes in the formation of unbalanced translocations in malignancy.

  15. Replicating centromeric chromatin: Spatial and temporal control of CENP-A assembly

    International Nuclear Information System (INIS)

    Nechemia-Arbely, Yael; Fachinetti, Daniele; Cleveland, Don W.

    2012-01-01

    The centromere is the fundamental unit for insuring chromosome inheritance. This complex region has a distinct type of chromatin in which histone H3 is replaced by a structurally different homologue identified in humans as CENP-A. In metazoans, specific DNA sequences are neither required nor sufficient for centromere identity. Rather, an epigenetic mark comprised of CENP-A containing chromatin is thought to be the major determinant of centromere identity. In this view, CENP-A deposition and chromatin assembly are fundamental processes for the maintenance of centromeric identity across mitotic and meiotic divisions. Several lines of evidence support CENP-A deposition in metazoans occurring at only one time in the cell cycle. Such cell cycle-dependent loading of CENP-A is found in divergent species from human to fission yeast, albeit with differences in the cell cycle point at which CENP-A is assembled. Cell cycle dependent CENP-A deposition requires multiple assembly factors for its deposition and maintenance. This review discusses the regulation of new CENP-A deposition and its relevance to centromere identity and inheritance.

  16. Centromeric DNA characterization in the model grass Brachypodium distachyon provides insights on the evolution of the genus.

    Science.gov (United States)

    Li, Yinjia; Zuo, Sheng; Zhang, Zhiliang; Li, Zhanjie; Han, Jinlei; Chu, Zhaoqing; Hasterok, Robert; Wang, Kai

    2018-03-01

    Brachypodium distachyon is a well-established model monocot plant, and its small and compact genome has been used as an accurate reference for the much larger and often polyploid genomes of cereals such as Avena sativa (oats), Hordeum vulgare (barley) and Triticum aestivum (wheat). Centromeres are indispensable functional units of chromosomes and they play a core role in genome polyploidization events during evolution. As the Brachypodium genus contains about 20 species that differ significantly in terms of their basic chromosome numbers, genome size, ploidy levels and life strategies, studying their centromeres may provide important insight into the structure and evolution of the genome in this interesting and important genus. In this study, we isolated the centromeric DNA of the B. distachyon reference line Bd21 and characterized its composition via the chromatin immunoprecipitation of the nucleosomes that contain the centromere-specific histone CENH3. We revealed that the centromeres of Bd21 have the features of typical multicellular eukaryotic centromeres. Strikingly, these centromeres contain relatively few centromeric satellite DNAs; in particular, the centromere of chromosome 5 (Bd5) consists of only ~40 kb. Moreover, the centromeric retrotransposons in B. distachyon (CRBds) are evolutionarily young. These transposable elements are located both within and adjacent to the CENH3 binding domains, and have similar compositions. Moreover, based on the presence of CRBds in the centromeres, the species in this study can be grouped into two distinct lineages. This may provide new evidence regarding the phylogenetic relationships within the Brachypodium genus. © 2018 The Authors The Plant Journal © 2018 John Wiley & Sons Ltd.

  17. Mps1 kinase-dependent Sgo2 centromere localisation mediates cohesin protection in mouse oocyte meiosis I.

    Science.gov (United States)

    El Yakoubi, Warif; Buffin, Eulalie; Cladière, Damien; Gryaznova, Yulia; Berenguer, Inés; Touati, Sandra A; Gómez, Rocío; Suja, José A; van Deursen, Jan M; Wassmann, Katja

    2017-09-25

    A key feature of meiosis is the step-wise removal of cohesin, the protein complex holding sister chromatids together, first from arms in meiosis I and then from the centromere region in meiosis II. Centromeric cohesin is protected by Sgo2 from Separase-mediated cleavage, in order to maintain sister chromatids together until their separation in meiosis II. Failures in step-wise cohesin removal result in aneuploid gametes, preventing the generation of healthy embryos. Here, we report that kinase activities of Bub1 and Mps1 are required for Sgo2 localisation to the centromere region. Mps1 inhibitor-treated oocytes are defective in centromeric cohesin protection, whereas oocytes devoid of Bub1 kinase activity, which cannot phosphorylate H2A at T121, are not perturbed in cohesin protection as long as Mps1 is functional. Mps1 and Bub1 kinase activities localise Sgo2 in meiosis I preferentially to the centromere and pericentromere respectively, indicating that Sgo2 at the centromere is required for protection.In meiosis I centromeric cohesin is protected by Sgo2 from Separase-mediated cleavage ensuring that sister chromatids are kept together until their separation in meiosis II. Here the authors demonstrate that Bub1 and Mps1 kinase activities are required for Sgo2 localisation to the centromere region.

  18. Mps1 kinase-dependent Sgo2 centromere localisation mediates cohesin protection in mouse oocyte meiosis I

    NARCIS (Netherlands)

    Yakoubi, W. El; Buffin, E.; Cladiere, D.; Gryaznova, Y.; Berenguer, I.; Touati, S.A.; Gomez, R.; Suja, J.A.; Deursen, J.M.A. van; Wassmann, K.

    2017-01-01

    A key feature of meiosis is the step-wise removal of cohesin, the protein complex holding sister chromatids together, first from arms in meiosis I and then from the centromere region in meiosis II. Centromeric cohesin is protected by Sgo2 from Separase-mediated cleavage, in order to maintain sister

  19. Phylogeny of horse chromosome 5q in the genus Equus and centromere repositioning.

    Science.gov (United States)

    Piras, F M; Nergadze, S G; Poletto, V; Cerutti, F; Ryder, O A; Leeb, T; Raimondi, E; Giulotto, E

    2009-01-01

    Horses, asses and zebras belong to the genus Equus and are the only extant species of the family Equidae in the order Perissodactyla. In a previous work we demonstrated that a key factor in the rapid karyotypic evolution of this genus was evolutionary centromere repositioning, that is, the shift of the centromeric function to a new position without alteration of the order of markers along the chromosome. In search of previously undiscovered evolutionarily new centromeres, we traced the phylogeny of horse chromosome 5, analyzing the order of BAC markers, derived from a horse genomic library, in 7 Equus species (E. caballus, E. hemionus onager, E. kiang, E. asinus, E. grevyi, E. burchelli and E. zebra hartmannae). This analysis showed that repositioned centromeres are present in E. asinus (domestic donkey, EAS) chromosome 16 and in E. burchelli (Burchell's zebra, EBU) chromosome 17, confirming that centromere repositioning is a strikingly frequent phenomenon in this genus. The observation that the neocentromeres in EAS16 and EBU17 are in the same chromosomal position suggests that they may derive from the same event and therefore, E. asinus and E. burchelli may be more closely related than previously proposed; alternatively, 2 centromere repositioning events, involving the same chromosomal region, may have occurred independently in different lineages, pointing to the possible existence of hot spots for neocentromere formation. Our comparative analysis also showed that, while E. caballus chromosome 5 seems to represent the ancestral configuration, centric fission followed by independent fusion events gave rise to 3 different submetacentric chromosomes in other Equus lineages. (c) 2009 S. Karger AG, Basel.

  20. Meiosis-Specific Loading of the Centromere-Specific Histone CENH3 in Arabidopsis thaliana

    Science.gov (United States)

    Ravi, Maruthachalam; Shibata, Fukashi; Ramahi, Joseph S.; Nagaki, Kiyotaka; Chen, Changbin; Murata, Minoru; Chan, Simon W. L.

    2011-01-01

    Centromere behavior is specialized in meiosis I, so that sister chromatids of homologous chromosomes are pulled toward the same side of the spindle (through kinetochore mono-orientation) and chromosome number is reduced. Factors required for mono-orientation have been identified in yeast. However, comparatively little is known about how meiotic centromere behavior is specialized in animals and plants that typically have large tandem repeat centromeres. Kinetochores are nucleated by the centromere-specific histone CENH3. Unlike conventional histone H3s, CENH3 is rapidly evolving, particularly in its N-terminal tail domain. Here we describe chimeric variants of CENH3 with alterations in the N-terminal tail that are specifically defective in meiosis. Arabidopsis thaliana cenh3 mutants expressing a GFP-tagged chimeric protein containing the H3 N-terminal tail and the CENH3 C-terminus (termed GFP-tailswap) are sterile because of random meiotic chromosome segregation. These defects result from the specific depletion of GFP-tailswap protein from meiotic kinetochores, which contrasts with its normal localization in mitotic cells. Loss of the GFP-tailswap CENH3 variant in meiosis affects recruitment of the essential kinetochore protein MIS12. Our findings suggest that CENH3 loading dynamics might be regulated differently in mitosis and meiosis. As further support for our hypothesis, we show that GFP-tailswap protein is recruited back to centromeres in a subset of pollen grains in GFP-tailswap once they resume haploid mitosis. Meiotic recruitment of the GFP-tailswap CENH3 variant is not restored by removal of the meiosis-specific cohesin subunit REC8. Our results reveal the existence of a specialized loading pathway for CENH3 during meiosis that is likely to involve the hypervariable N-terminal tail. Meiosis-specific CENH3 dynamics may play a role in modulating meiotic centromere behavior. PMID:21695238

  1. Somatic association of telocentric chromosomes carrying homologous centromeres in common wheat.

    Science.gov (United States)

    Mello-Sampayo, T

    1973-01-01

    Measurements of distances between telocentric chromosomes, either homologous or representing the opposite arms of a metacentric chromosome (complementary telocentrics), were made at metaphase in root tip cells of common wheat carrying two homologous pairs of complementary telocentrics of chromosome 1 B or 6 B (double ditelosomic 1 B or 6 B). The aim was to elucidate the relative locations of the telocentric chromosomes within the cell. The data obtained strongly suggest that all four telocentrics of chromosome 1 B or 6 B are spacially and simultaneously co-associated. In plants carrying two complementary (6 B (S) and 6 B (L)) and a non-related (5 B (L)) telocentric, only the complementary chromosomes were found to be somatically associated. It is thought, therefore, that the somatic association of chromosomes may involve more than two chromosomes in the same association and, since complementary telocentrics are as much associated as homologous, that the homology between centromeres (probably the only homologous region that exists between complementary telocentrics) is a very important condition for somatic association of chromosomes. The spacial arrangement of chromosomes was studied at anaphase and prophase and the polar orientation of chromosomes at prophase was found to resemble anaphase orientation. This was taken as good evidence for the maintenance of the chromosome arrangement - the Rabl orientation - and of the peripheral location of the centromere and its association with the nuclear membrane. Within this general arrangement homologous telocentric chromosomes were frequently seen to have their centromeres associated or directed towards each other. The role of the centromere in somatic association as a spindle fibre attachment and chromosome binder is discussed. It is suggested that for non-homologous chromosomes to become associated in root tips, the only requirement needed should be the homology of centromeres such as exists between complementary

  2. Correlation between chromosome 9p21 locus deletion and prognosis in clinically localized prostate cancer.

    Science.gov (United States)

    Barros, Érika Aparecida Felix de; Pontes-Junior, José; Reis, Sabrina Thalita; Lima, Amanda Eunice Ramos; Souza, Isida C; Salgueiro, Jose Lucas; Fontes, Douglas; Dellê, Humberto; Coelho, Rafael Ferreira; Viana, Nayara Izabel; Leite, Kátia Ramos Moreira; Nahas, William C; Srougi, Miguel

    2017-05-04

    Some studies have reported that deletions at chromosome arm 9p occur frequently and represent a critical step in carcinogenesis of some neoplasms. Our aim was to evaluate the deletion of locus 9p21 and chromosomes 3, 7 and 17 in localized prostate cancer (PC) and correlate these alterations with prognostic factors and biochemical recurrence after surgery. We retrospectively evaluated surgical specimens from 111 patients with localized PC who underwent radical prostatectomy. Biochemical recurrence was defined as a prostate-specific antigen (PSA) >0.2 ng/mL and the mean postoperative follow-up was 123 months. The deletions were evaluated using fluorescence in situ hybridization with centromeric and locus-specific probes in a tissue microarray containing 2 samples from each patient. We correlated the occurrence of any deletion with pathological stage, Gleason score, ISUP grade group, PSA and biochemical recurrence. We observed a loss of any probe in only 8 patients (7.2%). The most common deletion was the loss of locus 9p21, which occurred in 6.4% of cases. Deletions of chromosomes 3, 7 and 17 were observed in 2.3%, 1.2% and 1.8% patients, respectively. There was no correlation between chromosome loss and Gleason score, ISUP, PSA or stage. Biochemical recurrence occurred in 83% cases involving 9p21 deletions. Loss of 9p21 locus was significantly associated with time to recurrence (p = 0.038). We found low rates of deletion in chromosomes 3, 7 and 17 and 9p21 locus. We observed that 9p21 locus deletion was associated with worse prognosis in localized PC treated by radical prostatectomy.

  3. ParABS Systems of the Four Replicons of Burkholderia cenocepacia: New Chromosome Centromeres Confer Partition Specificity†

    Science.gov (United States)

    Dubarry, Nelly; Pasta, Franck; Lane, David

    2006-01-01

    Most bacterial chromosomes carry an analogue of the parABS systems that govern plasmid partition, but their role in chromosome partition is ambiguous. parABS systems might be particularly important for orderly segregation of multipartite genomes, where their role may thus be easier to evaluate. We have characterized parABS systems in Burkholderia cenocepacia, whose genome comprises three chromosomes and one low-copy-number plasmid. A single parAB locus and a set of ParB-binding (parS) centromere sites are located near the origin of each replicon. ParA and ParB of the longest chromosome are phylogenetically similar to analogues in other multichromosome and monochromosome bacteria but are distinct from those of smaller chromosomes. The latter form subgroups that correspond to the taxa of their hosts, indicating evolution from plasmids. The parS sites on the smaller chromosomes and the plasmid are similar to the “universal” parS of the main chromosome but with a sequence specific to their replicon. In an Escherichia coli plasmid stabilization test, each parAB exhibits partition activity only with the parS of its own replicon. Hence, parABS function is based on the independent partition of individual chromosomes rather than on a single communal system or network of interacting systems. Stabilization by the smaller chromosome and plasmid systems was enhanced by mutation of parS sites and a promoter internal to their parAB operons, suggesting autoregulatory mechanisms. The small chromosome ParBs were found to silence transcription, a property relevant to autoregulation. PMID:16452432

  4. Novel Centromeric Loci of the Wine and Beer Yeast Dekkera bruxellensis CEN1 and CEN2

    DEFF Research Database (Denmark)

    Ishchuk, Olena P.; Vojvoda Zeljko, Tanja; Schifferdecker, Anna J.

    2016-01-01

    The wine and beer yeast Dekkera bruxellensis thrives in environments that are harsh and limiting, especially in concentrations with low oxygen and high ethanol. Its different strains' chromosomes greatly vary in number (karyotype). This study isolates two novel centromeric loci (CEN1 and CEN2...

  5. Epigenetic Histone Marks of Extended Meta-Polycentric Centromeres of Lathyrus and Pisum Chromosomes

    Czech Academy of Sciences Publication Activity Database

    Neumann, Pavel; Schubert, V.; Vrbová, Iva; Manning, Jasper Eugene; Houben, A.; Macas, Jiří

    2016-01-01

    Roč. 7, č. 234 (2016) ISSN 1664-462X R&D Projects: GA ČR(CZ) GAP501/11/1843 Institutional support: RVO:60077344 Keywords : Centromere structure * epigenetic modifications * histone phosphorylation * histone methylation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.298, year: 2016

  6. Genetic and physical mapping of two centromere-proximal regions of chromosome IV in Aspergillus nidulans

    DEFF Research Database (Denmark)

    Aleksenko, Alexei Y.; Nielsen, Michael Lynge; Clutterbuck, A.J.

    2001-01-01

    revision of the genetic map of the chromosome, including the position of the centromere, Comparison of physical and genetic maps indicates that meiotic recombination is low in subcentromeric DNA, its frequency being reduced from 1 crossover per 0.8 Mb to approximately 1 crossover per 5 Mb per meiosis...

  7. Correlation between centromere protein-F autoantibodies and cancer analyzed by enzyme-linked immunosorbent assay

    DEFF Research Database (Denmark)

    Welner, Simon; Trier, Nicole Hartwig; Morten Frisch, Morten

    2013-01-01

    Centromere protein-F (CENP-F) is a large nuclear protein of 367 kDa, which is involved in multiple mitosis-related events such as proper assembly of the kinetochores, stabilization of heterochromatin, chromosome alignment and mitotic checkpoint signaling. Several studies have shown a correlation...

  8. Nuclear organization in human sperm: preliminary evidence for altered sex chromosome centromere position in infertile males.

    Science.gov (United States)

    Finch, K A; Fonseka, K G L; Abogrein, A; Ioannou, D; Handyside, A H; Thornhill, A R; Hickson, N; Griffin, D K

    2008-06-01

    Many genetic defects with a chromosomal basis affect male reproduction via a range of different mechanisms. Chromosome position is a well-known marker of nuclear organization, and alterations in standard patterns can lead to disease phenotypes such as cancer, laminopathies and epilepsy. It has been demonstrated that normal mammalian sperm adopt a pattern with the centromeres aligning towards the nuclear centre. The purpose of this study was to test the hypothesis that altered chromosome position in the sperm head is associated with male infertility. The average nuclear positions of fluorescence in-situ hybridization signals for three centromeric probes (for chromosomes X, Y and 18) were compared in normoozoospermic men and in men with compromised semen parameters. In controls, the centromeres of chromosomes X, Y and 18 all occupied a central nuclear location. In infertile men the sex chromosomes appeared more likely to be distributed in a pattern not distinguishable from a random model. Our findings cast doubt on the reliability of centromeric probes for aneuploidy screening. The analysis of chromosome position in sperm heads should be further investigated for the screening of infertile men.

  9. Centromeres cluster de novo at the beginning of meiosis in Brachypodium distachyon.

    Directory of Open Access Journals (Sweden)

    Ruoyu Wen

    Full Text Available In most eukaryotes that have been studied, the telomeres cluster into a bouquet early in meiosis, and in wheat and its relatives and in Arabidopsis the centromeres pair at the same time. In Arabidopsis, the telomeres do not cluster as a typical telomere bouquet on the nuclear membrane but are associated with the nucleolus both somatically and at the onset of meiosis. We therefore assessed whether Brachypodium distachyon, a monocot species related to cereals and whose genome is approximately twice the size of Arabidopsis thaliana, also exhibited an atypical telomere bouquet and centromere pairing. In order to investigate the occurrence of a bouquet and centromere pairing in B distachyon, we first had to establish protocols for studying meiosis in this species. This enabled us to visualize chromosome behaviour in meiocytes derived from young B distachyon spikelets in three-dimensions by fluorescent in situ hybridization (FISH, and accurately to stage meiosis based on chromatin morphology in relation to spikelet size and the timing of sample collection. Surprisingly, this study revealed that the centromeres clustered as a single site at the same time as the telomeres also formed a bouquet or single cluster.

  10. Molecular structures of centromeric heterochromatin and karyotypic evolution in the Siamese crocodile (Crocodylus siamensis) (Crocodylidae, Crocodylia).

    Science.gov (United States)

    Kawagoshi, Taiki; Nishida, Chizuko; Ota, Hidetoshi; Kumazawa, Yoshinori; Endo, Hideki; Matsuda, Yoichi

    2008-01-01

    Crocodilians have several unique karyotypic features, such as small diploid chromosome numbers (30-42) and the absence of dot-shaped microchromosomes. Of the extant crocodilian species, the Siamese crocodile (Crocodylus siamensis) has no more than 2n = 30, comprising mostly bi-armed chromosomes with large centromeric heterochromatin blocks. To investigate the molecular structures of C-heterochromatin and genomic compartmentalization in the karyotype, characterized by the disappearance of tiny microchromosomes and reduced chromosome number, we performed molecular cloning of centromeric repetitive sequences and chromosome mapping of the 18S-28S rDNA and telomeric (TTAGGG)( n ) sequences. The centromeric heterochromatin was composed mainly of two repetitive sequence families whose characteristics were quite different. Two types of GC-rich CSI-HindIII family sequences, the 305 bp CSI-HindIII-S (G+C content, 61.3%) and 424 bp CSI-HindIII-M (63.1%), were localized to the intensely PI-stained centric regions of all chromosomes, except for chromosome 2 with PI-negative heterochromatin. The 94 bp CSI-DraI (G+C content, 48.9%) was tandem-arrayed satellite DNA and localized to chromosome 2 and four pairs of small-sized chromosomes. The chromosomal size-dependent genomic compartmentalization that is supposedly unique to the Archosauromorpha was probably lost in the crocodilian lineage with the disappearance of microchromosomes followed by the homogenization of centromeric repetitive sequences between chromosomes, except for chromosome 2.

  11. Transgenerational propagation and quantitative maintenance of paternal centromeres depends on Cid/Cenp-A presence in Drosophila sperm.

    Directory of Open Access Journals (Sweden)

    Nitika Raychaudhuri

    Full Text Available In Drosophila melanogaster, as in many animal and plant species, centromere identity is specified epigenetically. In proliferating cells, a centromere-specific histone H3 variant (CenH3, named Cid in Drosophila and Cenp-A in humans, is a crucial component of the epigenetic centromere mark. Hence, maintenance of the amount and chromosomal location of CenH3 during mitotic proliferation is important. Interestingly, CenH3 may have different roles during meiosis and the onset of embryogenesis. In gametes of Caenorhabditis elegans, and possibly in plants, centromere marking is independent of CenH3. Moreover, male gamete differentiation in animals often includes global nucleosome for protamine exchange that potentially could remove CenH3 nucleosomes. Here we demonstrate that the control of Cid loading during male meiosis is distinct from the regulation observed during the mitotic cycles of early embryogenesis. But Cid is present in mature sperm. After strong Cid depletion in sperm, paternal centromeres fail to integrate into the gonomeric spindle of the first mitosis, resulting in gynogenetic haploid embryos. Furthermore, after moderate depletion, paternal centromeres are unable to re-acquire normal Cid levels in the next generation. We conclude that Cid in sperm is an essential component of the epigenetic centromere mark on paternal chromosomes and it exerts quantitative control over centromeric Cid levels throughout development. Hence, the amount of Cid that is loaded during each cell cycle appears to be determined primarily by the preexisting centromeric Cid, with little flexibility for compensation of accidental losses.

  12. Esperanto for histones: CENP-A, not CenH3, is the centromeric histone H3 variant.

    Science.gov (United States)

    Earnshaw, W C; Allshire, R C; Black, B E; Bloom, K; Brinkley, B R; Brown, W; Cheeseman, I M; Choo, K H A; Copenhaver, G P; Deluca, J G; Desai, A; Diekmann, S; Erhardt, S; Fitzgerald-Hayes, M; Foltz, D; Fukagawa, T; Gassmann, R; Gerlich, D W; Glover, D M; Gorbsky, G J; Harrison, S C; Heun, P; Hirota, T; Jansen, L E T; Karpen, G; Kops, G J P L; Lampson, M A; Lens, S M; Losada, A; Luger, K; Maiato, H; Maddox, P S; Margolis, R L; Masumoto, H; McAinsh, A D; Mellone, B G; Meraldi, P; Musacchio, A; Oegema, K; O'Neill, R J; Salmon, E D; Scott, K C; Straight, A F; Stukenberg, P T; Sullivan, B A; Sullivan, K F; Sunkel, C E; Swedlow, J R; Walczak, C E; Warburton, P E; Westermann, S; Willard, H F; Wordeman, L; Yanagida, M; Yen, T J; Yoda, K; Cleveland, D W

    2013-04-01

    The first centromeric protein identified in any species was CENP-A, a divergent member of the histone H3 family that was recognised by autoantibodies from patients with scleroderma-spectrum disease. It has recently been suggested to rename this protein CenH3. Here, we argue that the original name should be maintained both because it is the basis of a long established nomenclature for centromere proteins and because it avoids confusion due to the presence of canonical histone H3 at centromeres.

  13. DFNB79: reincarnation of a nonsyndromic deafness locus on chromosome 9q34.3.

    Science.gov (United States)

    Khan, Shahid Yar; Riazuddin, Saima; Shahzad, Mohsin; Ahmed, Nazir; Zafar, Ahmad Usman; Rehman, Atteeq Ur; Morell, Robert J; Griffith, Andrew J; Ahmed, Zubair M; Riazuddin, Sheikh; Friedman, Thomas B

    2010-01-01

    Genetic analysis of an inbred Pakistani family PKDF280, segregating prelingual severe to profound sensorineural hearing loss, provided evidence for a DFNB locus on human chromosome 9q34.3. Co-segregation of the deafness trait with marker D9SH159 was determined by a two-point linkage analysis (LOD score 9.43 at theta=0). Two additional large families, PKDF517 and PKDF741, co-segregate recessive deafness with markers linked to the same interval. Haplotype analyses of these three families refined the interval to 3.84 Mb defined by D9S1818 (centromeric) and D9SH6 (telomeric). This interval overlaps with the previously reported DFNB33 locus whose chromosomal map position has been recently revised and assigned to a new position on chromosome 10p11.23-q21.1. The nonsyndromic deafness locus on chromosome 9q segregating in family PKDF280 was designated DFNB79. We are currently screening the 113 candidate DFNB79 genes for mutations and have excluded CACNA1B, EDF1, PTGDS, EHMT1, QSOX2, NOTCH1, MIR126 and MIR602.

  14. Fine-Mapping of the 1p11.2 Breast Cancer Susceptibility Locus

    DEFF Research Database (Denmark)

    Horne, Hisani N; Chung, Charles C; Zhang, Han

    2016-01-01

    rs11249433 in 45,276 breast cancer cases and 48,998 controls of European, Asian and African ancestry from 50 studies in the Breast Cancer Association Consortium. Genotyping was done using iCOGS, a custom-built array. Due to the complicated nature of the region on chr1p11.2: 120......The Cancer Genetic Markers of Susceptibility genome-wide association study (GWAS) originally identified a single nucleotide polymorphism (SNP) rs11249433 at 1p11.2 associated with breast cancer risk. To fine-map this locus, we genotyped 92 SNPs in a 900kb region (120,505,799-121,481,132) flanking......,300,000-120,505,798, that lies near the centromere and contains seven duplicated genomic segments, we restricted analyses to 429 SNPs excluding the duplicated regions (42 genotyped and 387 imputed). Per-allelic associations with breast cancer risk were estimated using logistic regression models adjusting for study and ancestry...

  15. Absence of positive selection on CenH3 in Luzula suggests that holokinetic chromosomes may suppress centromere drive.

    Science.gov (United States)

    Zedek, František; Bureš, Petr

    2016-12-01

    The centromere drive theory explains diversity of eukaryotic centromeres as a consequence of the recurrent conflict between centromeric repeats and centromeric histone H3 (CenH3), in which selfish centromeres exploit meiotic asymmetry and CenH3 evolves adaptively to counterbalance deleterious consequences of driving centromeres. Accordingly, adaptively evolving CenH3 has so far been observed only in eukaryotes with asymmetric meiosis. However, if such evolution is a consequence of centromere drive, it should depend not only on meiotic asymmetry but also on monocentric or holokinetic chromosomal structure. Selective pressures acting on CenH3 have never been investigated in organisms with holokinetic meiosis despite the fact that holokinetic chromosomes have been hypothesized to suppress centromere drive. Therefore, the present study evaluates selective pressures acting on the CenH3 gene in holokinetic organisms for the first time, specifically in the representatives of the plant genus Luzula (Juncaceae), in which the kinetochore formation is not co-localized with any type of centromeric repeat. PCR, cloning and sequencing, and database searches were used to obtain coding CenH3 sequences from Luzula species. Codon substitution models were employed to infer selective regimes acting on CenH3 in Luzula KEY RESULTS: In addition to the two previously published CenH3 sequences from L. nivea, 16 new CenH3 sequences have been isolated from 12 Luzula species. Two CenH3 isoforms in Luzula that originated by a duplication event prior to the divergence of analysed species were found. No signs of positive selection acting on CenH3 in Luzula were detected. Instead, evidence was found that selection on CenH3 of Luzula might have been relaxed. The results indicate that holokinetism itself may suppress centromere drive and, therefore, holokinetic chromosomes might have evolved as a defence against centromere drive. © The Author 2016. Published by Oxford University Press on behalf of

  16. Human artificial chromosomes with alpha satellite-based de novo centromeres show increased frequency of nondisjunction and anaphase lag.

    Science.gov (United States)

    Rudd, M Katharine; Mays, Robert W; Schwartz, Stuart; Willard, Huntington F

    2003-11-01

    Human artificial chromosomes have been used to model requirements for human chromosome segregation and to explore the nature of sequences competent for centromere function. Normal human centromeres require specialized chromatin that consists of alpha satellite DNA complexed with epigenetically modified histones and centromere-specific proteins. While several types of alpha satellite DNA have been used to assemble de novo centromeres in artificial chromosome assays, the extent to which they fully recapitulate normal centromere function has not been explored. Here, we have used two kinds of alpha satellite DNA, DXZ1 (from the X chromosome) and D17Z1 (from chromosome 17), to generate human artificial chromosomes. Although artificial chromosomes are mitotically stable over many months in culture, when we examined their segregation in individual cell divisions using an anaphase assay, artificial chromosomes exhibited more segregation errors than natural human chromosomes (P artificial chromosomes missegregate over a fivefold range, the data suggest that variable centromeric DNA content and/or epigenetic assembly can influence the mitotic behavior of artificial chromosomes.

  17. B chromosomes and Robertsonian fusions of Dichroplus pratensis (Acrididae): intraspecific support for the centromeric drive theory.

    Science.gov (United States)

    Bidau, C J; Martí, D A

    2004-01-01

    We tested the centromeric drive theory of karyotypic evolution in the grasshopper Dichroplus pratensis, which is simultaneously polymorphic for eight Robertsonian fusions and two classes of B chromosomes. A logistic regression analysis performed on 53 natural populations from Argentina revealed that B chromosomes are more probably found in populations with a higher proportion of acrocentric chromosomes, as the theory predicts. Furthermore, frequencies of B-carrying individuals are significantly negatively correlated with the mean frequency of different Robertsonian fusions per individual. No significant correlations between presence/absence or frequency of Bs, and latitude or altitude of the sampled populations, were found. We thus provide the first intraspecific evidence supporting the centromeric drive theory in relation to the establishment of B chromosomes in natural populations. Copyright 2004 S. Karger AG, Basel

  18. Mating-type switching by chromosomal inversion in methylotrophic yeasts suggests an origin for the three-locus Saccharomyces cerevisiae system.

    Science.gov (United States)

    Hanson, Sara J; Byrne, Kevin P; Wolfe, Kenneth H

    2014-11-11

    Saccharomyces cerevisiae has a complex system for switching the mating type of haploid cells, requiring the genome to have three mating-type (MAT)-like loci and a mechanism for silencing two of them. How this system originated is unknown, because the three-locus system is present throughout the family Saccharomycetaceae, whereas species in the sister Candida clade have only one locus and do not switch. Here we show that yeasts in a third clade, the methylotrophs, have a simpler two-locus switching system based on reversible inversion of a section of chromosome with MATa genes at one end and MATalpha genes at the other end. In Hansenula polymorpha the 19-kb invertible region lies beside a centromere so that, depending on the orientation, either MATa or MATalpha is silenced by centromeric chromatin. In Pichia pastoris, the orientation of a 138-kb invertible region puts either MATa or MATalpha beside a telomere and represses transcription of MATa2 or MATalpha2. Both species are homothallic, and inversion of their MAT regions can be induced by crossing two strains of the same mating type. The three-locus system of S. cerevisiae, which uses a nonconservative mechanism to replace DNA at MAT, likely evolved from a conservative two-locus system that swapped genes between expression and nonexpression sites by inversion. The increasing complexity of the switching apparatus, with three loci, donor bias, and cell lineage tracking, can be explained by continuous selection to increase sporulation ability in young colonies. Our results provide an evolutionary context for the diversity of switching and silencing mechanisms.

  19. Autoantibodies directed to centromere protein F in a patient with BRCA1 gene mutation

    OpenAIRE

    Moghaddas, Fiona; Joshua, Fredrick; Taylor, Roberta; Fritzler, Marvin J.; Toh, Ban Hock

    2016-01-01

    Background Autoantibodies directed to centromere protein F were first reported in 1993 and their association with malignancy has been well documented. Case We present the case of a 48-year-old Caucasian female with a BRCA1 gene mutation associated with bilateral breast cancer. Antinuclear autoantibody immunofluorescence performed for workup of possible inflammatory arthropathy showed a high titre cell cycle related nuclear speckled pattern, with subsequent confirmation by addressable laser be...

  20. Perturbation of Incenp function impedes anaphase chromatid movements and chromosomal passenger protein flux at centromeres.

    Science.gov (United States)

    Ahonen, Leena J; Kukkonen, Anu M; Pouwels, Jeroen; Bolton, Margaret A; Jingle, Christopher D; Stukenberg, P Todd; Kallio, Marko J

    2009-02-01

    Incenp is an essential mitotic protein that, together with Aurora B, Survivin, and Borealin, forms the core of the chromosomal passenger protein complex (CPC). The CPC regulates various mitotic processes and functions to maintain genomic stability. The proper subcellular localization of the CPC and its full catalytic activity require the presence of each core subunit in the complex. We have investigated the mitotic tasks of the CPC using a function blocking antibody against Incenp microinjected into cells at different mitotic phases. This method allowed temporal analysis of CPC functions without perturbation of complex assembly or activity prior to injection. We have also studied the dynamic properties of Incenp and Aurora B using fusion protein photobleaching. We found that in early mitotic cells, Incenp and Aurora B exhibit dynamic turnover at centromeres, which is prevented by the anti-Incenp antibody. In these cells, the loss of centromeric CPC turnover is accompanied by forced mitotic exit without the execution of cytokinesis. Introduction of anti-Incenp antibody into early anaphase cells causes abnormalities in sister chromatid separation through defects in anaphase spindle functions. In summary, our data uncovers new mitotic roles for the CPC in anaphase and proposes that CPC turnover at centromeres modulates spindle assembly checkpoint signaling.

  1. Positioning of chromosomes in human spermatozoa is determined by ordered centromere arrangement.

    Directory of Open Access Journals (Sweden)

    Olga S Mudrak

    Full Text Available The intranuclear positioning of chromosomes (CHRs is a well-documented fact; however, mechanisms directing such ordering remain unclear. Unlike somatic cells, human spermatozoa contain distinct spatial markers and have asymmetric nuclei which make them a unique model for localizing CHR territories and matching peri-centromere domains. In this study, we established statistically preferential longitudinal and lateral positioning for eight CHRs. Both parameters demonstrated a correlation with the CHR gene densities but not with their sizes. Intranuclear non-random positioning of the CHRs was found to be driven by a specific linear order of centromeres physically interconnected in continuous arrays. In diploid spermatozoa, linear order of peri-centromeres was identical in two genome sets and essentially matched the arrangement established for haploid cells. We propose that the non-random longitudinal order of CHRs in human spermatozoa is generated during meiotic stages of spermatogenesis. The specific arrangement of sperm CHRs may serve as an epigenetic basis for differential transcription/replication and direct spatial CHR organization during early embryogenesis.

  2. Separase Is Required for Homolog and Sister Disjunction during Drosophila melanogaster Male Meiosis, but Not for Biorientation of Sister Centromeres.

    Science.gov (United States)

    Blattner, Ariane C; Chaurasia, Soumya; McKee, Bruce D; Lehner, Christian F

    2016-04-01

    Spatially controlled release of sister chromatid cohesion during progression through the meiotic divisions is of paramount importance for error-free chromosome segregation during meiosis. Cohesion is mediated by the cohesin protein complex and cleavage of one of its subunits by the endoprotease separase removes cohesin first from chromosome arms during exit from meiosis I and later from the pericentromeric region during exit from meiosis II. At the onset of the meiotic divisions, cohesin has also been proposed to be present within the centromeric region for the unification of sister centromeres into a single functional entity, allowing bipolar orientation of paired homologs within the meiosis I spindle. Separase-mediated removal of centromeric cohesin during exit from meiosis I might explain sister centromere individualization which is essential for subsequent biorientation of sister centromeres during meiosis II. To characterize a potential involvement of separase in sister centromere individualization before meiosis II, we have studied meiosis in Drosophila melanogaster males where homologs are not paired in the canonical manner. Meiosis does not include meiotic recombination and synaptonemal complex formation in these males. Instead, an alternative homolog conjunction system keeps homologous chromosomes in pairs. Using independent strategies for spermatocyte-specific depletion of separase complex subunits in combination with time-lapse imaging, we demonstrate that separase is required for the inactivation of this alternative conjunction at anaphase I onset. Mutations that abolish alternative homolog conjunction therefore result in random segregation of univalents during meiosis I also after separase depletion. Interestingly, these univalents become bioriented during meiosis II, suggesting that sister centromere individualization before meiosis II does not require separase.

  3. Identification and Preliminary Analysis of Several Centromere-associated Bacterial Artificial Chromosome Clones from a Diploid Wheat Library

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Although the centromeres of some plants have been investigated previously, our knowledge of the wheat centromere is still very limited. To understand the structure and function of the wheat centromere, we used two centromeric repeats (RCS1 and CCS1-5ab) to obtain some centromere-associated bacterial artificial chromosome (BAC) clones in 32 RCS1-related BAC clones that had been screened out from a diploid wheat (Triticum boeoticum Boiss.; 2n=2x=14) BAC library. Southern hybridization results indicated that, of the 32 candidates,there were 28 RCS1-positive clones. Based on gel blot patterns, the frequency of RCS1 was approximately one copy every 69.4 kb in these 28 RCS1-positive BAC clones. More bands were detected when the same filter was probed with CCS1-5ab. Furthermore, the CCS1 bands covered all the bands detected by RCS1, which suggests that some CCS1 repeats were distributed together with RCS1. The frequency of CCS1 families was once every 35.8 kb, nearly twice that of RCS1. Fluorescence in situ hybridization (FISH) analysis indicated that the five BAC clones containing RCS1 and CCS1 sequences all detected signals at the centromeric regions in hexaploid wheat, but the signal intensities on the A-genome chromosomes were stronger than those on the B- and/or D-genome chromosomes. The FISH analysis among nine Triticeae cereals indicated that there were A-genomespecific (or rich) sequences dispersing on chromosome arms in the BAC clone TbBAC5. In addition, at the interphase cells, the centromeres of diploid species usually clustered at one pole and formed a ring-like allocation in the period before metaphase.

  4. Locus of Control and Obesity

    Directory of Open Access Journals (Sweden)

    Florence eNeymotin

    2014-10-01

    Full Text Available 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.

  5. Locus of control and obesity.

    Science.gov (United States)

    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.

  6. Centromere replication timing determines different forms of genomic instability in Saccharomyces cerevisiae checkpoint mutants during replication stress.

    Science.gov (United States)

    Feng, Wenyi; Bachant, Jeff; Collingwood, David; Raghuraman, M K; Brewer, Bonita J

    2009-12-01

    Yeast replication checkpoint mutants lose viability following transient exposure to hydroxyurea, a replication-impeding drug. In an effort to understand the basis for this lethality, we discovered that different events are responsible for inviability in checkpoint-deficient cells harboring mutations in the mec1 and rad53 genes. By monitoring genomewide replication dynamics of cells exposed to hydroxyurea, we show that cells with a checkpoint deficient allele of RAD53, rad53K227A, fail to duplicate centromeres. Following removal of the drug, however, rad53K227A cells recover substantial DNA replication, including replication through centromeres. Despite this recovery, the rad53K227A mutant fails to achieve biorientation of sister centromeres during recovery from hydroxyurea, leading to secondary activation of the spindle assembly checkpoint (SAC), aneuploidy, and lethal chromosome segregation errors. We demonstrate that cell lethality from this segregation defect could be partially remedied by reinforcing bipolar attachment. In contrast, cells with the mec1-1 sml1-1 mutations suffer from severely impaired replication resumption upon removal of hydroxyurea. mec1-1 sml1-1 cells can, however, duplicate at least some of their centromeres and achieve bipolar attachment, leading to abortive segregation and fragmentation of incompletely replicated chromosomes. Our results highlight the importance of replicating yeast centromeres early and reveal different mechanisms of cell death due to differences in replication fork progression.

  7. Regulation of Centromere Localization of the Drosophila Shugoshin MEI-S332 and Sister-Chromatid Cohesion in Meiosis

    Science.gov (United States)

    Nogueira, Cristina; Kashevsky, Helena; Pinto, Belinda; Clarke, Astrid; Orr-Weaver, Terry L.

    2014-01-01

    The Shugoshin (Sgo) protein family helps to ensure proper chromosome segregation by protecting cohesion at the centromere by preventing cleavage of the cohesin complex. Some Sgo proteins also influence other aspects of kinetochore-microtubule attachments. Although many Sgo members require Aurora B kinase to localize to the centromere, factors controlling delocalization are poorly understood and diverse. Moreover, it is not clear how Sgo function is inactivated and whether this is distinct from delocalization. We investigated these questions in Drosophila melanogaster, an organism with superb chromosome cytology to monitor Sgo localization and quantitative assays to test its function in sister-chromatid segregation in meiosis. Previous research showed that in mitosis in cell culture, phosphorylation of the Drosophila Sgo, MEI-S332, by Aurora B promotes centromere localization, whereas Polo phosphorylation promotes delocalization. These studies also suggested that MEI-S332 can be inactivated independently of delocalization, a conclusion supported here by localization and function studies in meiosis. Phosphoresistant and phosphomimetic mutants for the Aurora B and Polo phosphorylation sites were examined for effects on MEI-S332 localization and chromosome segregation in meiosis. Strikingly, MEI-S332 with a phosphomimetic mutation in the Aurora B phosphorylation site prematurely dissociates from the centromeres in meiosis I. Despite the absence of MEI-S332 on meiosis II centromeres in male meiosis, sister chromatids segregate normally, demonstrating that detectable levels of this Sgo are not essential for chromosome congression, kinetochore biorientation, or spindle assembly. PMID:25081981

  8. Characterization of the genomic organization of the region bordering the centromere of chromosome V of Podospora anserina by direct sequencing.

    Science.gov (United States)

    Silar, Philippe; Barreau, Christian; Debuchy, Robert; Kicka, Sébastien; Turcq, Béatrice; Sainsard-Chanet, Annie; Sellem, Carole H; Billault, Alain; Cattolico, Laurence; Duprat, Simone; Weissenbach, Jean

    2003-08-01

    A Podospora anserina BAC library of 4800 clones has been constructed in the vector pBHYG allowing direct selection in fungi. Screening of the BAC collection for centromeric sequences of chromosome V allowed the recovery of clones localized on either sides of the centromere, but no BAC clone was found to contain the centromere. Seven BAC clones containing 322,195 and 156,244bp from either sides of the centromeric region were sequenced and annotated. One 5S rRNA gene, 5 tRNA genes, and 163 putative coding sequences (CDS) were identified. Among these, only six CDS seem specific to P. anserina. The gene density in the centromeric region is approximately one gene every 2.8kb. Extrapolation of this gene density to the whole genome of P. anserina suggests that the genome contains about 11,000 genes. Synteny analyses between P. anserina and Neurospora crassa show that co-linearity extends at the most to a few genes, suggesting rapid genome rearrangements between these two species.

  9. Analysis of DNA restriction fragments greater than 5.7 Mb in size from the centromeric region of human chromosomes.

    Science.gov (United States)

    Arn, P H; Li, X; Smith, C; Hsu, M; Schwartz, D C; Jabs, E W

    1991-01-01

    Pulsed electrophoresis was used to study the organization of the human centromeric region. Genomic DNA was digested with rare-cutting enzymes. DNA fragments from 0.2 to greater than 5.7 Mb were separated by electrophoresis and hybridized with alphoid and simple DNA repeats. Rare-cutting enzymes (Mlu I, Nar I, Not I, Nru I, Sal I, Sfi I, Sst II) demonstrated fewer restriction sites at centromeric regions than elsewhere in the genome. The enzyme Not I had the fewest restriction sites at centromeric regions. As much as 70% of these sequences from the centromeric region are present in Not I DNA fragments greater than 5.7 and estimated to be as large as 10 Mb in size. Other repetitive sequences such as short interspersed repeated segments (SINEs), long interspersed repeated segments (LINEs), ribosomal DNA, and mini-satellite DNA that are not enriched at the centromeric region, are not enriched in Not I fragments of greater than 5.7 Mb in size.

  10. RNA Pol II promotes transcription of centromeric satellite DNA in beetles.

    Directory of Open Access Journals (Sweden)

    Zeljka Pezer

    Full Text Available Transcripts of centromeric satellite DNAs are known to play a role in heterochromatin formation as well as in establishment of the kinetochore. However, little is known about basic mechanisms of satellite DNA expression within constitutive heterochromatin and its regulation. Here we present comprehensive analysis of transcription of abundant centromeric satellite DNA, PRAT from beetle Palorus ratzeburgii (Coleoptera. This satellite is characterized by preservation and extreme sequence conservation among evolutionarily distant insect species. PRAT is expressed in all three developmental stages: larvae, pupae and adults at similar level. Transcripts are abundant comprising 0.033% of total RNA and are heterogeneous in size ranging from 0.5 kb up to more than 5 kb. Transcription proceeds from both strands but with 10 fold different expression intensity and transcripts are not processed into siRNAs. Most of the transcripts (80% are not polyadenylated and remain in the nucleus while a small portion is exported to the cytoplasm. Multiple, irregularly distributed transcription initiation sites as well as termination sites have been mapped within the PRAT sequence using primer extension and RLM-RACE. The presence of cap structure as well as poly(A tails in a portion of the transcripts indicate RNA polymerase II-dependent transcription and a putative polymerase II promoter site overlaps the most conserved part of the PRAT sequence. The treatment of larvae with alpha-amanitin decreases the level of PRAT transcripts at concentrations that selectively inhibit pol II activity. In conclusion, stable, RNA polymerase II dependant transcripts of abundant centromeric satellite DNA, not regulated by RNAi, have been identified and characterized. This study offers a basic understanding of expression of highly abundant heterochromatic DNA which in beetle species constitutes up to 50% of the genome.

  11. Quantitative trait locus affecting birth weight on bovine chromosome 5 in a F2 Gyr x Holstein population

    Directory of Open Access Journals (Sweden)

    Gustavo Gasparin

    2005-12-01

    Full Text Available Segregation between a genetic marker and a locus influencing a quantitative trait in a well delineated population is the basis for success in mapping quantitative trait loci (QTL. To detect bovine chromosome 5 (BTA5 birth weight QTL we genotyped 294 F2 Gyr (Bos indicus x Holstein (Bos taurus crossbreed cattle for five microsatellite markers. A linkage map was constructed for the markers and an interval analysis for the presence of QTL was performed. The linkage map indicated differences in the order of two markers relative to the reference map (http://www.marc.usda.gov. Interval analysis detected a QTL controlling birth weight (p < 0.01 at 69 centimorgans (cM from the most centromeric marker with an effect of 0.32 phenotypic standard-error. These results support other studies with crossbred Bos taurus x Bos indicus populations.

  12. Organization and evolution of primate centromeric DNA from whole-genome shotgun sequence data.

    Directory of Open Access Journals (Sweden)

    Can Alkan

    2007-09-01

    Full Text Available The major DNA constituent of primate centromeres is alpha satellite DNA. As much as 2%-5% of sequence generated as part of primate genome sequencing projects consists of this material, which is fragmented or not assembled as part of published genome sequences due to its highly repetitive nature. Here, we develop computational methods to rapidly recover and categorize alpha-satellite sequences from previously uncharacterized whole-genome shotgun sequence data. We present an algorithm to computationally predict potential higher-order array structure based on paired-end sequence data and then experimentally validate its organization and distribution by experimental analyses. Using whole-genome shotgun data from the human, chimpanzee, and macaque genomes, we examine the phylogenetic relationship of these sequences and provide further support for a model for their evolution and mutation over the last 25 million years. Our results confirm fundamental differences in the dispersal and evolution of centromeric satellites in the Old World monkey and ape lineages of evolution.

  13. Characterization of the oncogenic function of centromere protein F in hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Yongdong; Liu, Lulu; Zeng, Tingting; Zhu, Ying-Hui [State Key Laboratory of Oncology in Southern China, Sun Yat-Sen University Cancer Center, Guangzhou (China); Li, Jiangchao [Vascular Biology Research Institute, Guangdong Pharmaceutical University, Guangzhou (China); Chen, Leilei [Department of Clinical Oncology, The University of Hong Kong, Pokfulam, Hong Kong (China); Li, Yan; Yuan, Yun-Fei [State Key Laboratory of Oncology in Southern China, Sun Yat-Sen University Cancer Center, Guangzhou (China); Ma, Stephanie, E-mail: stefma@hku.hk [Department of Clinical Oncology, The University of Hong Kong, Pokfulam, Hong Kong (China); State Key Laboratory for Liver Research, The University of Hong Kong, Pokfulam, Hong Kong (China); Guan, Xin-Yuan, E-mail: xyguan@hkucc.hku.hk [State Key Laboratory of Oncology in Southern China, Sun Yat-Sen University Cancer Center, Guangzhou (China); Department of Clinical Oncology, The University of Hong Kong, Pokfulam, Hong Kong (China); State Key Laboratory for Liver Research, The University of Hong Kong, Pokfulam, Hong Kong (China)

    2013-07-12

    Highlights: •Overexpression of CENPF is frequently detected in HCC. •Upregulation of CENPF serves as an independent prognosis factor in HCC patients. •CENPF functions as an oncogene in HCC by promoting cell G2/M transition. -- Abstract: Centromere protein F (CENPF) is an essential nuclear protein associated with the centromere-kinetochore complex and plays a critical role in chromosome segregation during mitosis. Up-regulation of CENPF expression has previously been detected in several solid tumors. In this study, we aim to study the expression and functional role of CENPF in hepatocellular carcinoma (HCC). We found CENPF was frequently overexpressed in HCC as compared with non-tumor tissue. Up-regulated CENPF expression in HCC was positively correlated with serum AFP, venous invasion, advanced differentiation stage and a shorter overall survival. Cox regression analysis found that overexpression of CENPF was an independent prognosis factor in HCC. Functional studies found that silencing CENPF could decrease the ability of the cells to proliferate, form colonies and induce tumor formation in nude mice. Silencing CENPF also resulted in the cell cycle arrest at G2/M checkpoint by down-regulating cell cycle proteins cdc2 and cyclin B1. Our data suggest that CENPF is frequently overexpressed in HCC and plays a critical role in driving HCC tumorigenesis.

  14. Organization and evolution of primate centromeric DNA from whole-genome shotgun sequence data.

    Science.gov (United States)

    Alkan, Can; Ventura, Mario; Archidiacono, Nicoletta; Rocchi, Mariano; Sahinalp, S Cenk; Eichler, Evan E

    2007-09-01

    The major DNA constituent of primate centromeres is alpha satellite DNA. As much as 2%-5% of sequence generated as part of primate genome sequencing projects consists of this material, which is fragmented or not assembled as part of published genome sequences due to its highly repetitive nature. Here, we develop computational methods to rapidly recover and categorize alpha-satellite sequences from previously uncharacterized whole-genome shotgun sequence data. We present an algorithm to computationally predict potential higher-order array structure based on paired-end sequence data and then experimentally validate its organization and distribution by experimental analyses. Using whole-genome shotgun data from the human, chimpanzee, and macaque genomes, we examine the phylogenetic relationship of these sequences and provide further support for a model for their evolution and mutation over the last 25 million years. Our results confirm fundamental differences in the dispersal and evolution of centromeric satellites in the Old World monkey and ape lineages of evolution.

  15. Comparative cytogenetic analysis of chromosomal aberrations and premature centromere division in persons exposed to radionuclides

    International Nuclear Information System (INIS)

    Jovicic, D.; Rakic, B.; Vukov, T.; Pajic, J.; Milacic, S.; Kovacevic, R.; Stevanovic, M.; Drakulic, D.; Bukvic, N.

    2009-01-01

    The aim of the research was to determine the presence of correlation between the frequency of premature centromere division (PCD) and chromosomal aberrations (CA) in metaphases in persons professionally exposed to radionuclides. Biological dosimetry was performed by conventional cytogenetic technique. The presence of PCD was confirmed by Fluorescent in situ hybridization (FISH). The L1.84 probe (specific for centromeric region of chromosome 18) was used. The analysis included 50 subjects employed in the Clinical Center of Serbia (C) (the average age of 45.24 ± 1.18 and the average exposition time 17.96 ± 1.15) and 40 subjects in control group (K) (the average age of 44.40 ± 0.98 and the average years of employment 19.67 ± 0.98 years) which were not exposed to genotoxic agents in their workplaces. The results showed that frequencies of CA and PCD were statistically significantly higher in subjects exposed to radionuclides than in the control group (Mann-Whitney U test, P [sr

  16. The Ties that Bind (the Igh Locus).

    Science.gov (United States)

    Krangel, Michael S

    2016-05-01

    Immunoglobulin heavy-chain locus V(D)J recombination requires a 3D chromatin organization which permits widely distributed variable (V) gene segments to contact distant diversity (D) and joining (J) gene segments. A recent study has identified key nodes in the locus interactome, paving the way for new molecular insights into how the locus is configured for recombination. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. B chromosomes are more frequent in mammals with acrocentric karyotypes: support for the theory of centromeric drive.

    Science.gov (United States)

    Palestis, Brian G; Burt, Austin; Jones, R Neil; Trivers, Robert

    2004-02-07

    The chromosomes of mammals tend to be either mostly acrocentric (having one long arm) or mostly bi-armed, with few species having intermediate karyotypes. The theory of centromeric drive suggests that this observation reflects a bias during female meiosis, favouring either more centromeres or fewer, and that the direction of this bias changes frequently over evolutionary time. B chromosomes are selfish genetic elements found in some individuals within some species. B chromosomes are often harmful, but persist because they drive (i.e. they are transmitted more frequently than expected). We predicted that species with mainly acrocentric chromosomes would be more likely to harbour B chromosomes than those with mainly bi-armed chromosomes, because female meiosis would favour more centromeres over fewer in species with one-armed chromosomes. Our results show that B chromosomes are indeed more common in species with acrocentric chromosomes, across all mammals, among rodents, among non-rodents and in a test of independent taxonomic contrasts. These results provide independent evidence supporting the theory of centromeric drive and also help to explain the distribution of selfish DNA across species. In addition, we demonstrate an association between the shape of the B chromosomes and the shape of the typical ('A') chromosomes.

  18. The TubR-centromere complex adopts a double-ring segrosome structure in Type III partition systems.

    Science.gov (United States)

    Martín-García, Bárbara; Martín-González, Alejandro; Carrasco, Carolina; Hernández-Arriaga, Ana M; Ruíz-Quero, Rubén; Díaz-Orejas, Ramón; Aicart-Ramos, Clara; Moreno-Herrero, Fernando; Oliva, María A

    2018-05-14

    In prokaryotes, the centromere is a specialized segment of DNA that promotes the assembly of the segrosome upon binding of the Centromere Binding Protein (CBP). The segrosome structure exposes a specific surface for the interaction of the CBP with the motor protein that mediates DNA movement during cell division. Additionally, the CBP usually controls the transcriptional regulation of the segregation system as a cell cycle checkpoint. Correct segrosome functioning is therefore indispensable for accurate DNA segregation. Here, we combine biochemical reconstruction and structural and biophysical analysis to bring light to the architecture of the segrosome complex in Type III partition systems. We present the particular features of the centromere site, tubC, of the model system encoded in Clostridium botulinum prophage c-st. We find that the split centromere site contains two different iterons involved in the binding and spreading of the CBP, TubR. The resulting nucleoprotein complex consists of a novel double-ring structure that covers part of the predicted promoter. Single molecule data provides a mechanism for the formation of the segrosome structure based on DNA bending and unwinding upon TubR binding.

  19. A cytogenetic study of hospital workers occupationally exposed to radionuclides in Serbia. Premature centromere division as novel biomarker of exposure?

    Energy Technology Data Exchange (ETDEWEB)

    Pajic, Jelena; Rakic, Boban [Serbian Institute of Occupational Health ' ' Dr Dragomir Karajovic' ' , Belgrade (Serbia). Biodosimetry Dept.; Jovicic, Dubravka [Univ. ' ' Singidunum' ' , Belgrade (Serbia). Genotoxicology Dept.; Milovanovic, Aleksandar [Serbian Institute of Occupational Health ' ' Dr Dragomir Karajovic' ' , Belgrade (Serbia). Biodosimetry Dept.; Belgrade Univ. (Serbia). Occupational Health Dept.

    2016-04-15

    The health risk of chronic exposure to radionuclides includes changes in the genome (e.g., chromosomal aberrations and micronuclei) that increase chromosomal instability. There are also other phenomena, which seem to appear more frequently in metaphases of exposed persons (such as premature centromere division). The aim of this study was to discover whether or not there is correlation between incidence of named cytogenetic changes in persons occupationally exposed to radionuclides in comparison with unexposed control group, and if significant correlation is determined, can premature centromere division be consider as a biomarker of radiation exposure? The exposed group comprised 50 individuals occupationally exposed to radionuclides. The reference control group consisted of 40 unexposed individuals. Chromosomal aberrations, micronuclei and premature centromere division were analyzed according to a standard International Atomic Energy Agency protocol. Statistical analyses were performed using SPSS 17.0 statistics.The means for analyzed cytogenetic changes were significantly higher in the exposed group. Positive correlation between them was found in exposed group. Premature centromere division parameter PCD5-10 was selected as particularly suitable for separating groups (exposed/unexposed). Identification of other phenomena related to radionuclide exposure, beside well known, may clarify recent problems in radiobiology concerning the biological response to low doses of ionizing radiation and its consequences.

  20. Single molecule localization imaging of telomeres and centromeres using fluorescence in situ hybridization and semiconductor quantum dots.

    Science.gov (United States)

    Wang, Le; Zong, Shenfei; Wang, Zhuyuan; Lu, Ju; Chen, Chen; Zhang, Ruohu; Cui, Yiping

    2018-07-13

    Single molecule localization microscopy (SMLM) is a powerful tool for imaging biological targets at the nanoscale. In this report, we present SMLM imaging of telomeres and centromeres using fluorescence in situ hybridization (FISH). The FISH probes were fabricated by decorating CdSSe/ZnS quantum dots (QDs) with telomere or centromere complementary DNA strands. SMLM imaging experiments using commercially available peptide nucleic acid (PNA) probes labeled with organic fluorophores were also conducted to demonstrate the advantages of using QDs FISH probes. Compared with the PNA probes, the QDs probes have the following merits. First, the fluorescence blinking of QDs can be realized in aqueous solution or PBS buffer without thiol, which is a key buffer component for organic fluorophores' blinking. Second, fluorescence blinking of the QDs probe needs only one excitation light (i.e. 405 nm). While fluorescence blinking of the organic fluorophores usually requires two illumination lights, that is, the activation light (i.e. 405 nm) and the imaging light. Third, the high quantum yield, multiple switching times and a good optical stability make the QDs more suitable for long-term imaging. The localization precision achieved in telomeres and centromeres imaging experiments is about 30 nm, which is far beyond the diffraction limit. SMLM has enabled new insights into telomeres or centromeres on the molecular level, and it is even possible to determine the length of telomere and become a potential technique for telomere-related investigation.

  1. A cytogenetic study of hospital workers occupationally exposed to radionuclides in Serbia. Premature centromere division as novel biomarker of exposure?

    International Nuclear Information System (INIS)

    Pajic, Jelena; Rakic, Boban; Jovicic, Dubravka; Milovanovic, Aleksandar; Belgrade Univ.

    2016-01-01

    The health risk of chronic exposure to radionuclides includes changes in the genome (e.g., chromosomal aberrations and micronuclei) that increase chromosomal instability. There are also other phenomena, which seem to appear more frequently in metaphases of exposed persons (such as premature centromere division). The aim of this study was to discover whether or not there is correlation between incidence of named cytogenetic changes in persons occupationally exposed to radionuclides in comparison with unexposed control group, and if significant correlation is determined, can premature centromere division be consider as a biomarker of radiation exposure? The exposed group comprised 50 individuals occupationally exposed to radionuclides. The reference control group consisted of 40 unexposed individuals. Chromosomal aberrations, micronuclei and premature centromere division were analyzed according to a standard International Atomic Energy Agency protocol. Statistical analyses were performed using SPSS 17.0 statistics.The means for analyzed cytogenetic changes were significantly higher in the exposed group. Positive correlation between them was found in exposed group. Premature centromere division parameter PCD5-10 was selected as particularly suitable for separating groups (exposed/unexposed). Identification of other phenomena related to radionuclide exposure, beside well known, may clarify recent problems in radiobiology concerning the biological response to low doses of ionizing radiation and its consequences.

  2. Genetics Ustilago violacea. XXXIII. Genetic evidence for insertional mutations in the magenta locus

    International Nuclear Information System (INIS)

    Garber, E.D.; Ruddat, M.

    1996-01-01

    Three spontaneous mutants (m-1, m-2, and m-31) with a new sporidial colony color (magenta, m) were found in the stable pink 1.A1 a-1 and 2.A2 a-2 laboratory strains. The m-1 and white (w) mutations were very closely linked (<0.1 cM); the m locus was assumed to be distal from the w locus and in the same chromosome arm. The color mutations formed a map of very closely linked (<1 cM), centromere-linked loci: orange (o)-pumpkin (p)-yellow (y)-centr-wA-wB-m. Crosses between the m-1 and m-2 mutants, between the m-2 mutant and laboratory strains with a different color, and between the m-2 mutant and strains from the herbarium/field collections gave nonsectored and sectored teliospore colonies with a nonparental color. All of the teliospores colonies from cross AV13 involving strains 1.C417* y and 2.C413 p had a nonparental color or different nonparental colors, including magenta. The UV-irradiation of m-1, m-2, and m-31 sporidia gave mostly pink (+) colonies, ranging from 9% to 48%. Occasional nonsectored w and p colonies as well as one bisectored m/+ and one w/+ colony were found. Approximately 103 m-1 sporidia were UV-irradiated, and the following colonies with a nonparental color were found: w (one), p (three), o (one), +f (one), ms (supermagenta) (one), and m/+ (one). Crosses involving the m-2 mutant and the +f, ms, p, w, and y mutants indicated that the +f and ms mutants resulted from an insertional mutation and the others from a genic mutation. Sites of element insertion were (1) most likely in the pericentric regions to give the pink phenotype, (2) less likely in the y and p loci in the same chromosome arm and in the complex w locus, and (3) least likely in the o locus in one arm and m locus in the other arm. These observations were explained by proposing the transcentric transposition of a cryptic or a transactive element in the homologous chromosome with the color mutations during meiosis and to the UV-induced transposition of an element in sporidia

  3. Genetic mapping of centromeres in the nine Citrus clementina chromosomes using half-tetrad analysis and recombination patterns in unreduced and haploid gametes.

    Science.gov (United States)

    Aleza, Pablo; Cuenca, José; Hernández, María; Juárez, José; Navarro, Luis; Ollitrault, Patrick

    2015-03-08

    Mapping centromere locations in plant species provides essential information for the analysis of genetic structures and population dynamics. The centromere's position affects the distribution of crossovers along a chromosome and the parental heterozygosity restitution by 2n gametes is a direct function of the genetic distance to the centromere. Sexual polyploidisation is relatively frequent in Citrus species and is widely used to develop new seedless triploid cultivars. The study's objectives were to (i) map the positions of the centromeres of the nine Citrus clementina chromosomes; (ii) analyse the crossover interference in unreduced gametes; and (iii) establish the pattern of genetic recombination in haploid clementine gametes along each chromosome and its relationship with the centromere location and distribution of genic sequences. Triploid progenies were derived from unreduced megagametophytes produced by second-division restitution. Centromere positions were mapped genetically for all linkage groups using half-tetrad analysis. Inference of the physical locations of centromeres revealed one acrocentric, four metacentric and four submetacentric chromosomes. Crossover interference was observed in unreduced gametes, with variation seen between chromosome arms. For haploid gametes, a strong decrease in the recombination rate occurred in centromeric and pericentromeric regions, which contained a low density of genic sequences. In chromosomes VIII and IX, these low recombination rates extended beyond the pericentromeric regions. The genomic region corresponding to a genetic distance recombination pattern along each chromosome. However, regions with low recombination rates extended beyond the pericentromeric regions of some chromosomes into areas richer in genic sequences. The persistence of strong linkage disequilibrium between large numbers of genes promotes the stability of epistatic interactions and multilocus-controlled traits over successive generations but

  4. The cohesion protein SOLO associates with SMC1 and is required for synapsis, recombination, homolog bias and cohesion and pairing of centromeres in Drosophila Meiosis.

    Science.gov (United States)

    Yan, Rihui; McKee, Bruce D

    2013-01-01

    Cohesion between sister chromatids is mediated by cohesin and is essential for proper meiotic segregation of both sister chromatids and homologs. solo encodes a Drosophila meiosis-specific cohesion protein with no apparent sequence homology to cohesins that is required in male meiosis for centromere cohesion, proper orientation of sister centromeres and centromere enrichment of the cohesin subunit SMC1. In this study, we show that solo is involved in multiple aspects of meiosis in female Drosophila. Null mutations in solo caused the following phenotypes: 1) high frequencies of homolog and sister chromatid nondisjunction (NDJ) and sharply reduced frequencies of homolog exchange; 2) reduced transmission of a ring-X chromosome, an indicator of elevated frequencies of sister chromatid exchange (SCE); 3) premature loss of centromere pairing and cohesion during prophase I, as indicated by elevated foci counts of the centromere protein CID; 4) instability of the lateral elements (LE)s and central regions of synaptonemal complexes (SCs), as indicated by fragmented and spotty staining of the chromosome core/LE component SMC1 and the transverse filament protein C(3)G, respectively, at all stages of pachytene. SOLO and SMC1 are both enriched on centromeres throughout prophase I, co-align along the lateral elements of SCs and reciprocally co-immunoprecipitate from ovarian protein extracts. Our studies demonstrate that SOLO is closely associated with meiotic cohesin and required both for enrichment of cohesin on centromeres and stable assembly of cohesin into chromosome cores. These events underlie and are required for stable cohesion of centromeres, synapsis of homologous chromosomes, and a recombination mechanism that suppresses SCE to preferentially generate homolog crossovers (homolog bias). We propose that SOLO is a subunit of a specialized meiotic cohesin complex that mediates both centromeric and axial arm cohesion and promotes homolog bias as a component of chromosome

  5. Analysis of Primary Structural Determinants That Distinguish the Centromere-Specific Function of Histone Variant Cse4p from Histone H3

    OpenAIRE

    Keith, Kevin C.; Baker, Richard E.; Chen, Yinhuai; Harris, Kendra; Stoler, Sam; Fitzgerald-Hayes, Molly

    1999-01-01

    Cse4p is a variant of histone H3 that has an essential role in chromosome segregation and centromere chromatin structure in budding yeast. Cse4p has a unique 135-amino-acid N terminus and a C-terminal histone-fold domain that is more than 60% identical to histone H3 and the mammalian centromere protein CENP-A. Cse4p and CENP-A have biochemical properties similar to H3 and probably replace H3 in centromere-specific nucleosomes in yeasts and mammals, respectively. In order to identify regions o...

  6. Mutations in CENPE define a novel kinetochore-centromeric mechanism for microcephalic primordial dwarfism.

    Science.gov (United States)

    Mirzaa, Ghayda M; Vitre, Benjamin; Carpenter, Gillian; Abramowicz, Iga; Gleeson, Joseph G; Paciorkowski, Alex R; Cleveland, Don W; Dobyns, William B; O'Driscoll, Mark

    2014-08-01

    Defects in centrosome, centrosomal-associated and spindle-associated proteins are the most frequent cause of primary microcephaly (PM) and microcephalic primordial dwarfism (MPD) syndromes in humans. Mitotic progression and segregation defects, microtubule spindle abnormalities and impaired DNA damage-induced G2-M cell cycle checkpoint proficiency have been documented in cell lines from these patients. This suggests that impaired mitotic entry, progression and exit strongly contribute to PM and MPD. Considering the vast protein networks involved in coordinating this cell cycle stage, the list of potential target genes that could underlie novel developmental disorders is large. One such complex network, with a direct microtubule-mediated physical connection to the centrosome, is the kinetochore. This centromeric-associated structure nucleates microtubule attachments onto mitotic chromosomes. Here, we described novel compound heterozygous variants in CENPE in two siblings who exhibit a profound MPD associated with developmental delay, simplified gyri and other isolated abnormalities. CENPE encodes centromere-associated protein E (CENP-E), a core kinetochore component functioning to mediate chromosome congression initially of misaligned chromosomes and in subsequent spindle microtubule capture during mitosis. Firstly, we present a comprehensive clinical description of these patients. Then, using patient cells we document abnormalities in spindle microtubule organization, mitotic progression and segregation, before modeling the cellular pathogenicity of these variants in an independent cell system. Our cellular analysis shows that a pathogenic defect in CENP-E, a kinetochore-core protein, largely phenocopies PCNT-mutated microcephalic osteodysplastic primordial dwarfism-type II patient cells. PCNT encodes a centrosome-associated protein. These results highlight a common underlying pathomechanism. Our findings provide the first evidence for a kinetochore-based route to

  7. Immunohistochemical Assessment of Expression of Centromere Protein—A (CENPA) in Human Invasive Breast Cancer

    International Nuclear Information System (INIS)

    Rajput, Ashish B.; Hu, Nianping; Varma, Sonal; Chen, Chien-Hung; Ding, Keyue; Park, Paul C.; Chapman, Judy-Anne W.; SenGupta, Sandip K.; Madarnas, Yolanda; Elliott, Bruce E.; Feilotter, Harriet E.

    2011-01-01

    Abnormal cell division leading to the gain or loss of entire chromosomes and consequent genetic instability is a hallmark of cancer. Centromere protein –A (CENPA) is a centromere-specific histone-H3-like variant gene involved in regulating chromosome segregation during cell division. CENPA is one of the genes included in some of the commercially available RNA based prognostic assays for breast cancer (BCa)—the 70 gene signature MammaPrint ® and the five gene Molecular Grade Index (MGI SM ). Our aim was to assess the immunohistochemical (IHC) expression of CENPA in normal and malignant breast tissue. Clinically annotated triplicate core tissue microarrays of 63 invasive BCa and 20 normal breast samples were stained with a monoclonal antibody against CENPA and scored for percentage of visibly stained nuclei. Survival analyses with Kaplan–Meier (KM) estimate and Cox proportional hazards regression models were applied to assess the associations between CENPA expression and disease free survival (DFS). Average percentage of nuclei visibly stained with CENPA antibody was significantly higher (p = 0.02) in BCa than normal tissue. The 3-year DFS in tumors over-expressing CENPA (>50% stained nuclei) was 79% compared to 85% in low expression tumors (<50% stained nuclei). On multivariate analysis, IHC expression of CENPA showed weak association with DFS (HR > 60.07; p = 0.06) within our small cohort. To the best of our knowledge, this is the first published report evaluating the implications of increased IHC expression of CENPA in paraffin embedded breast tissue samples. Our finding that increased CENPA expression may be associated with shorter DFS in BCa supports its exploration as a potential prognostic biomarker

  8. Immunohistochemical Assessment of Expression of Centromere Protein—A (CENPA) in Human Invasive Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Rajput, Ashish B. [Department of Pathology and Molecular Medicine, Queen' s University, Kingston, ON K7L 3N6 (Canada); Hu, Nianping [Cancer Research institute, Queen' s University, Kingston, ON K7L 3N6 (Canada); Varma, Sonal; Chen, Chien-Hung [Department of Pathology and Molecular Medicine, Queen' s University, Kingston, ON K7L 3N6 (Canada); Ding, Keyue [NCIC Clinical Trials Group, Queen' s University, Kingston, ON K7L 3N6 (Canada); Park, Paul C. [Department of Pathology and Molecular Medicine, Queen' s University, Kingston, ON K7L 3N6 (Canada); Chapman, Judy-Anne W. [NCIC Clinical Trials Group, Queen' s University, Kingston, ON K7L 3N6 (Canada); SenGupta, Sandip K. [Department of Pathology and Molecular Medicine, Queen' s University, Kingston, ON K7L 3N6 (Canada); Madarnas, Yolanda [Cancer Research institute, Queen' s University, Kingston, ON K7L 3N6 (Canada); Department of Oncology, Cancer Center of Southeastern Ontario, Kingston, ON K7L 2V7 (Canada); Elliott, Bruce E.; Feilotter, Harriet E., E-mail: feilotth@kgh.kari.net [Department of Pathology and Molecular Medicine, Queen' s University, Kingston, ON K7L 3N6 (Canada)

    2011-12-06

    Abnormal cell division leading to the gain or loss of entire chromosomes and consequent genetic instability is a hallmark of cancer. Centromere protein –A (CENPA) is a centromere-specific histone-H3-like variant gene involved in regulating chromosome segregation during cell division. CENPA is one of the genes included in some of the commercially available RNA based prognostic assays for breast cancer (BCa)—the 70 gene signature MammaPrint{sup ®} and the five gene Molecular Grade Index (MGI{sup SM}). Our aim was to assess the immunohistochemical (IHC) expression of CENPA in normal and malignant breast tissue. Clinically annotated triplicate core tissue microarrays of 63 invasive BCa and 20 normal breast samples were stained with a monoclonal antibody against CENPA and scored for percentage of visibly stained nuclei. Survival analyses with Kaplan–Meier (KM) estimate and Cox proportional hazards regression models were applied to assess the associations between CENPA expression and disease free survival (DFS). Average percentage of nuclei visibly stained with CENPA antibody was significantly higher (p = 0.02) in BCa than normal tissue. The 3-year DFS in tumors over-expressing CENPA (>50% stained nuclei) was 79% compared to 85% in low expression tumors (<50% stained nuclei). On multivariate analysis, IHC expression of CENPA showed weak association with DFS (HR > 60.07; p = 0.06) within our small cohort. To the best of our knowledge, this is the first published report evaluating the implications of increased IHC expression of CENPA in paraffin embedded breast tissue samples. Our finding that increased CENPA expression may be associated with shorter DFS in BCa supports its exploration as a potential prognostic biomarker.

  9. Locus: mede-ontwikkelaar van inclusieve arbeidsorganisaties

    NARCIS (Netherlands)

    Beukema, Leni; de Lange, Annet; Wielenga-Meijer, Etty; Duijker, Theo; Hanstede, Bram

    2018-01-01

    in deze bijdrage wordt Locus beschreven, een netwerk waarin publieke partijen en grote, landelijk opererende bedrijven samenwerken om mensen met een afstand tot de arbeidsmarkt duurzaam aan het werk te helpen. Het hoofdstuk start met de ontstaansgeschiedenis en benadering van Locus. Vervolgens wordt

  10. Genetic and physical maps around the sex-determining M-locus of the dioecious plant asparagus.

    Science.gov (United States)

    Telgmann-Rauber, Alexa; Jamsari, Ari; Kinney, Michael S; Pires, J Chris; Jung, Christian

    2007-09-01

    Asparagus officinalis L. is a dioecious plant. A region called the M-locus located on a pair of homomorphic sex chromosomes controls the sexual dimorphism in asparagus. The aim of this work was to clone the region determining sex in asparagus from its position in the genome. The structure of the region encompassing M should be investigated and compared to the sex-determining regions in other dioecious model species. To establish an improved basis for physical mapping, a high-resolution genetic map was enriched with AFLP markers closely linked to the target locus by carrying out a bulked segregant analysis. By screening a BAC library with AFLP- and STS-markers followed by chromosome walking, a physical map with eight contigs could be established. However, the gaps between the contigs could not be closed due to a plethora of repetitive elements. Surprisingly, two of the contigs on one side of the M-locus did not overlap although they have been established with two markers, which mapped in a distance as low as 0.25 cM flanking the sex locus. Thus, the clustering of the markers indicates a reduced recombination frequency within the M-region. On the opposite side of the M-locus, a contig was mapped in a distance of 0.38 cM. Four closely linked BAC clones were partially sequenced and 64 putative ORFs were identified. Interestingly, only 25% of the ORFs showed sequence similarity to known proteins and ESTs. In addition, an accumulation of repetitive sequences and a low gene density was revealed in the sex-determining region of asparagus. Molecular cytogenetic and sequence analysis of BACs flanking the M-locus indicate that the BACs contain highly repetitive sequences that localize to centromeric and pericentromeric locations on all asparagus chromosomes, which hindered the localization of the M-locus to the single pair of sex chromosomes. We speculate that dioecious Silene, papaya and Asparagus species may represent three stages in the evolution of XX, XY sex

  11. EL LOCUS DE DISTRIBUCION COMO COROLARIO DEL LOCUS DE CONTROL

    Directory of Open Access Journals (Sweden)

    Luisa Mayoral

    2009-01-01

    Full Text Available Este es un artículo científico acerca del Locus de Distribución, surgido de un estudio realizado con una población de docentes y alumnos universitarios. Respecto de los primeros, se ha indagado acerca de las atribuciones que se realizaban en torno a las recompensas y sanciones, que ellos distribuían a sus alumnos. Respecto de los segundos, se ha buscado determinar la valoración que estos realizaban de sus profesores, en términos de aquellas atribuciones. Para ello, se utilizaron dos paradigmas clásicamente empleados para verificar la existencia de una norma: el paradigma de la autopresentación (docentes, y el paradigma de los juicios (alumnos. La cuestión planteada fue determinar si en el caso de los comportamientos distributivos de refuerzos, las causas se atribuían a variables externas -en particular a los receptores de esos refuerzos- y si esas formas de atribución eran conocidas y valoradas o no, por los alumnos. De los resultados, surgió la confirmación de nuestra hipótesis de explicaciones externas en materia de comportamientos distributivos de sanciones en el ámbito de la docencia y la valoración positiva de estas atribuciones por los alumnos.

  12. Translocations affecting human immunoglobulin heavy chain locus

    Directory of Open Access Journals (Sweden)

    Sklyar I. V.

    2014-03-01

    Full Text Available Translocations involving human immunoglobulin heavy chain (IGH locus are implicated in different leukaemias and lymphomas, including multiple myeloma, mantle cell lymphoma, Burkitt’s lymphoma and diffuse large B cell lymphoma. We have analysed published data and identified eleven breakpoint cluster regions (bcr related to these cancers within the IgH locus. These ~1 kbp bcrs are specific for one or several types of blood cancer. Our findings could help devise PCR-based assays to detect cancer-related translocations, to identify the mechanisms of translocations and to help in the research of potential translocation partners of the immunoglobulin locus at different stages of B-cell differentiation.

  13. Extensive gene conversion at the PMS2 DNA mismatch repair locus.

    Science.gov (United States)

    Hayward, Bruce E; De Vos, Michel; Valleley, Elizabeth M A; Charlton, Ruth S; Taylor, Graham R; Sheridan, Eamonn; Bonthron, David T

    2007-05-01

    Mutations of the PMS2 DNA repair gene predispose to a characteristic range of malignancies, with either childhood onset (when both alleles are mutated) or a partially penetrant adult onset (if heterozygous). These mutations have been difficult to detect, due to interference from a family of pseudogenes located on chromosome 7. One of these, the PMS2CL pseudogene, lies within a 100-kb inverted duplication (inv dup), 700 kb centromeric to PMS2 itself on 7p22. Here, we show that the reference genomic sequences cannot be relied upon to distinguish PMS2 from PMS2CL, because of sequence transfer between the two loci. The 7p22 inv dup occurred prior to the divergence of modern ape species (15 million years ago [Mya]), but has undergone extensive sequence homogenization. This process appears to be ongoing, since there is considerable allelic diversity within the duplicated region, much of it derived from sequence exchange between PMS2 and PMS2CL. This sequence diversity can result in both false-positive and false-negative mutation analysis at this locus. Great caution is still needed in the design and interpretation of PMS2 mutation screens. 2007 Wiley-Liss, Inc.

  14. Complementation analyses for 45 mutations encompassing the pink-eyed dilution (p) locus of the mouse

    Energy Technology Data Exchange (ETDEWEB)

    Russell, L.B.; Montgomery, C.S.; Cacheiro, N.L.A.; Johnson, D.K. [Oak Ridge National Lab., TN (United States)

    1995-12-01

    The homozygous and heterozygous phenotypes are described and characterized for 45 new pink-eyed dilution (p) locus mutations, most of them radiation-induced, that affect survival at various stages of mouse development. Cytogenetically detectable aberrations were found in three of the new p mutations (large deletion, inversion, translocation), with band 7C involved in each case. The complementation map developed from the study of 810 types of compound heterozygotes identifies five functional units: jls and jlm (two distinct juvenile-fitness functions, the latter associated with neuromuscular defects), pl-1 and pl-2 (associated with early-postimplantation and preimplantation death, respectively), and nl [neonatal lethality associated with cleft palate (the frequency of rare {open_quotes}escapers{close_quotes} from this defect varied with the genotype)]. Orientation of these units relative to genetic markers is as follows: centromere, Gas-2, pl-1, jls, jlm p, nl (equatable to cp1= Gabrb3); pl-2 probably resides in the c-deletion complex. pl-1 does not mask preimplantation lethals between Gas2 and p; and no genes affecting survival are located between p and cp1. The alleles specifying mottling or darker pigment (generically, p{sup m} and p{sup x}, respectively) probably do not represent deletions of p-coding sequences but could be small rearrangements involving proximal regulatory elements. 43 refs., 5 figs., 7 tabs.

  15. Large scale genomic reorganization of topological domains at the HoxD locus.

    Science.gov (United States)

    Fabre, Pierre J; Leleu, Marion; Mormann, Benjamin H; Lopez-Delisle, Lucille; Noordermeer, Daan; Beccari, Leonardo; Duboule, Denis

    2017-08-07

    The transcriptional activation of HoxD genes during mammalian limb development involves dynamic interactions with two topologically associating domains (TADs) flanking the HoxD cluster. In particular, the activation of the most posterior HoxD genes in developing digits is controlled by regulatory elements located in the centromeric TAD (C-DOM) through long-range contacts. To assess the structure-function relationships underlying such interactions, we measured compaction levels and TAD discreteness using a combination of chromosome conformation capture (4C-seq) and DNA FISH. We assessed the robustness of the TAD architecture by using a series of genomic deletions and inversions that impact the integrity of this chromatin domain and that remodel long-range contacts. We report multi-partite associations between HoxD genes and up to three enhancers. We find that the loss of native chromatin topology leads to the remodeling of TAD structure following distinct parameters. Our results reveal that the recomposition of TAD architectures after large genomic re-arrangements is dependent on a boundary-selection mechanism in which CTCF mediates the gating of long-range contacts in combination with genomic distance and sequence specificity. Accordingly, the building of a recomposed TAD at this locus depends on distinct functional and constitutive parameters.

  16. Holocentromeres in Rhynchospora are associated with genome-wide centromere-specific repeat arrays interspersed among euchromatin

    Czech Academy of Sciences Publication Activity Database

    Marques, A.; Ribeiro, T.; Neumann, Pavel; Macas, Jiří; Novák, Petr; Schubert, V.; Pellino, M.; Fuchs, J.; Ma, W.; Kuhlmann, M.; Brandt, R.; Vanzela, A.L.L.; Beseda, Tomáš; Šimková, Hana; Pedrosa-Harand, A.; Houben, A.

    2015-01-01

    Roč. 112, č. 44 (2015), s. 13633-13638 ISSN 0027-8424 R&D Projects: GA ČR GBP501/12/G090; GA MŠk(CZ) LO1204 Institutional support: RVO:60077344 ; RVO:61389030 Keywords : Centromere * satellite DNA * holokinetic * chromosome Subject RIV: EB - Genetics ; Molecular Biology; EB - Genetics ; Molecular Biology (UEB-Q) Impact factor: 9.423, year: 2015

  17. Culture, gender and locus of control

    DEFF Research Database (Denmark)

    Ottsen, Christina Lundsgaard; Johannessen, Kim Berg; Berntsen, Dorthe

    The current study is a cross-cultural comparison between the Middle East and Scandinavia. Two societies that offer a unique opportunity to examine gender differences in personal goals and how goals are affected by locus of control.......The current study is a cross-cultural comparison between the Middle East and Scandinavia. Two societies that offer a unique opportunity to examine gender differences in personal goals and how goals are affected by locus of control....

  18. A recombination outside the BB deletion refines the location of the X-linked retinitis pigmentosa locus RP3

    Energy Technology Data Exchange (ETDEWEB)

    Fujita, R.; Bingham, E.; Forsythe, P.; McHenry, C. [Univ. of Michigan, Ann Arbor, MI (United States)] [and others

    1996-07-01

    Genetic loci for X-linked retinitis pigmentosa (XLRP) have been mapped between Xp11.22 and Xp22.13 (RP2, RP3, RP6, and RP15). The RP3 gene, which is responsible for the predominant form of XLRP in most Caucasian populations, has been localized to Xp21.1 by linkage analysis and the map positions of chromosomal deletions associated with the disease. Previous linkage studies have suggested that RP3 is flanked by the markers DXS1110 (distal) and OTC (proximal). Patient BB was though to have RP because of a lesion at the RP3 locus, in addition to chronic granulomatous disease, Duchenne muscular dystrophy (DMD), mild mental retardation, and the McLeod phenotype. This patient carried a deletion extending {approximately}3 Mb from DMD in Xp21.3 to Xp21.1, with the proximal breakpoint located {approximately}40 kb centromeric to DXS1110. The RP3 gene, therefore, is believed to reside between DXS1110 and the proximal breakpoint of the BB deletion. In order to refine the location of RP3 and to ascertain patients with RP3, we have been analyzing several XLRP families for linkage to Xp markers. Linkage analysis in an American family of 27 individuals demonstrates segregation of XLRP with markers in Xp21.1, consistent with the RP3 subtype. One affected male shows a recombination event proximal to DXS1110. Additional markers within the DXS1110-OTC interval show that the crossover is between two novel polymorphic markers, DXS8349 and M6, both of which are present in BB DNA and lie centromeric to the proximal breakpoint. This recombination places the XLRP mutation in this family outside the BB deletion and redefines the location of RP3. 22 refs., 3 figs., 2 tabs.

  19. Chromosome segregation regulation in human zygotes: altered mitotic histone phosphorylation dynamics underlying centromeric targeting of the chromosomal passenger complex.

    Science.gov (United States)

    van de Werken, C; Avo Santos, M; Laven, J S E; Eleveld, C; Fauser, B C J M; Lens, S M A; Baart, E B

    2015-10-01

    Are the kinase feedback loops that regulate activation and centromeric targeting of the chromosomal passenger complex (CPC), functional during mitosis in human embryos? Investigation of the regulatory kinase pathways involved in centromeric CPC targeting revealed normal phosphorylation dynamics of histone H2A at T120 (H2ApT120) by Bub1 kinase and subsequent recruitment of Shugoshin, but phosphorylation of histone H3 at threonine 3 (H3pT3) by Haspin failed to show the expected centromeric enrichment on metaphase chromosomes in the zygote. Human cleavage stage embryos show high levels of chromosomal instability. What causes this high error rate is unknown, as mechanisms used to ensure proper chromosome segregation in mammalian embryos are poorly described. In this study, we investigated the pathways regulating CPC targeting to the inner centromere in human embryos. We characterized the distribution of the CPC in relation to activity of its two main centromeric targeting pathways: the Bub1-H2ApT120-Sgo-CPC and Haspin-H3pT3-CPC pathways. The study was conducted between May 2012 and March 2014 on human surplus embryos resulting from in vitro fertilization treatment and donated for research. In zygotes, nuclear envelope breakdown was monitored by time-lapse imaging to allow timed incubations with specific inhibitors to arrest at prometaphase and metaphase, and to interfere with Haspin and Aurora B/C kinase activity. Functionality of the targeting pathways was assessed through characterization of histone phosphorylation dynamics by immunofluorescent analysis, combined with gene expression by RT-qPCR and immunofluorescent localization of key pathway proteins. Immunofluorescent analysis of the CPC subunit Inner Centromere Protein revealed the pool of stably bound CPC proteins was not strictly confined to the inner centromere of prometaphase chromosomes in human zygotes, as observed in later stages of preimplantation development and somatic cells. Investigation of the

  20. Locus of control in relation to flow

    Directory of Open Access Journals (Sweden)

    Celeste M Taylor

    2006-04-01

    Full Text Available The principal objective of the study was to examine the relationship between locus of control and optimal experience (flow in carrying out work and/or study activities. Two questionnaires measuring the aforementioned constructs were administered to a group of first and second-year Human Resource Management students (n=168 between the ages of 16 and 30. The results suggest that more frequent experience of flow is positively correlated with Autonomy and Internal Locus of Control. Limitations, lines of future research, implications and further contributions are discussed.

  1. The LOCUS interface to the MFE database

    International Nuclear Information System (INIS)

    Miner, W.H. Jr.

    1991-01-01

    The MFE database now consists of over 900 shots from TFTR, PDX, PLT, T-10, JT-60, TEXT, JET and ASDEX. A variety of discharge conditions is represented, ranging from single time slice Ohmic discharges to multiple time-slice auxiliary heated discharges. Included with most datasets is a reference that describes the experiment being performed when the data was taken. The MFE database is currently implemented under INGRES on a VAX that is on Internet. LOCUS, a database utility, developed at the Princeton Plasma Physics Laboratory is now available as an interface to the database. The LOCUS front end provides a graphic interface to the database from any generic graphics terminal that supports Tektronix 4010 emulation. It provides a variety of procedures for extracting, manipulating and graphing data from the MFE database. In order to demonstrate the capabilities of the LOCUS interface, the authors examine, in detail, one of the recently added JET, H-mode discharges. In this example, they address some new concepts such as monitor functions, which have been introduced in order to help users more fully understand the multiple time-slice datasets. They also describe some of the more advanced techniques available in LOCUS for data access and manipulation. Specific areas of interest that are discussed are searching for and retrieving datasets, graphics, data fitting, and linear regression analysis

  2. Toxoplasma gondii chromodomain protein 1 binds to heterochromatin and colocalises with centromeres and telomeres at the nuclear periphery.

    Directory of Open Access Journals (Sweden)

    Mathieu Gissot

    Full Text Available BACKGROUND: Apicomplexan parasites are responsible for some of the most deadly parasitic diseases afflicting humans, including malaria and toxoplasmosis. These obligate intracellular parasites exhibit a complex life cycle and a coordinated cell cycle-dependant expression program. Their cell division is a coordinated multistep process. How this complex mechanism is organised remains poorly understood. METHODS AND FINDINGS: In this study, we provide evidence for a link between heterochromatin, cell division and the compartmentalisation of the nucleus in Toxoplasma gondii. We characterised a T. gondii chromodomain containing protein (named TgChromo1 that specifically binds to heterochromatin. Using ChIP-on-chip on a genome-wide scale, we report TgChromo1 enrichment at the peri-centromeric chromatin. In addition, we demonstrate that TgChromo1 is cell-cycle regulated and co-localised with markers of the centrocone. Through the loci-specific FISH technique for T. gondii, we confirmed that TgChromo1 occupies the same nuclear localisation as the peri-centromeric sequences. CONCLUSION: We propose that TgChromo1 may play a role in the sequestration of chromosomes at the nuclear periphery and in the process of T. gondii cell division.

  3. MHF1-2/CENP-S-X performs distinct roles in centromere metabolism and genetic recombination.

    Science.gov (United States)

    Bhattacharjee, Sonali; Osman, Fekret; Feeney, Laura; Lorenz, Alexander; Bryer, Claire; Whitby, Matthew C

    2013-09-11

    The histone-fold proteins Mhf1/CENP-S and Mhf2/CENP-X perform two important functions in vertebrate cells. First, they are components of the constitutive centromere-associated network, aiding kinetochore assembly and function. Second, they work with the FANCM DNA translocase to promote DNA repair. However, it has been unclear whether there is crosstalk between these roles. We show that Mhf1 and Mhf2 in fission yeast, as in vertebrates, serve a dual function, aiding DNA repair/recombination and localizing to centromeres to promote chromosome segregation. Importantly, these functions are distinct, with the former being dependent on their interaction with the FANCM orthologue Fml1 and the latter not. Together with Fml1, they play a second role in aiding chromosome segregation by processing sister chromatid junctions. However, a failure of this activity does not manifest dramatically increased levels of chromosome missegregation due to the Mus81-Eme1 endonuclease, which acts as a failsafe to resolve DNA junctions before the end of mitosis.

  4. Loss of maternal ATRX results in centromere instability and aneuploidy in the mammalian oocyte and pre-implantation embryo.

    Directory of Open Access Journals (Sweden)

    Claudia Baumann

    2010-09-01

    Full Text Available The α-thalassemia/mental retardation X-linked protein (ATRX is a chromatin-remodeling factor known to regulate DNA methylation at repetitive sequences of the human genome. We have previously demonstrated that ATRX binds to pericentric heterochromatin domains in mouse oocytes at the metaphase II stage where it is involved in mediating chromosome alignment at the meiotic spindle. However, the role of ATRX in the functional differentiation of chromatin structure during meiosis is not known. To test ATRX function in the germ line, we developed an oocyte-specific transgenic RNAi knockdown mouse model. Our results demonstrate that ATRX is required for heterochromatin formation and maintenance of chromosome stability during meiosis. During prophase I arrest, ATRX is necessary to recruit the transcriptional regulator DAXX (death domain associated protein to pericentric heterochromatin. At the metaphase II stage, transgenic ATRX-RNAi oocytes exhibit abnormal chromosome morphology associated with reduced phosphorylation of histone 3 at serine 10 as well as chromosome segregation defects leading to aneuploidy and severely reduced fertility. Notably, a large proportion of ATRX-depleted oocytes and 1-cell stage embryos exhibit chromosome fragments and centromeric DNA-containing micronuclei. Our results provide novel evidence indicating that ATRX is required for centromere stability and the epigenetic control of heterochromatin function during meiosis and the transition to the first mitosis.

  5. The Impact of Locus of Control on Language Achievement

    Science.gov (United States)

    Nodoushan, Mohammad Ali Salmani

    2012-01-01

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

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

    Science.gov (United States)

    Sterbin, Allan; Rakow, Ernest

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

  7. Fluorescence In Situ Hybridization (FISH-Based Karyotyping Reveals Rapid Evolution of Centromeric and Subtelomeric Repeats in Common Bean (Phaseolus vulgaris and Relatives

    Directory of Open Access Journals (Sweden)

    Aiko Iwata-Otsubo

    2016-04-01

    Full Text Available Fluorescence in situ hybridization (FISH-based karyotyping is a powerful cytogenetics tool to study chromosome organization, behavior, and chromosome evolution. Here, we developed a FISH-based karyotyping system using a probe mixture comprised of centromeric and subtelomeric satellite repeats, 5S rDNA, and chromosome-specific BAC clones in common bean, which enables one to unambiguously distinguish all 11 chromosome pairs. Furthermore, we applied the karyotyping system to several wild relatives and landraces of common bean from two distinct gene pools, as well as other related Phaseolus species, to investigate repeat evolution in the genus Phaseolus. Comparison of karyotype maps within common bean indicates that chromosomal distribution of the centromeric and subtelomeric satellite repeats is stable, whereas the copy number of the repeats was variable, indicating rapid amplification/reduction of the repeats in specific genomic regions. In Phaseolus species that diverged approximately 2–4 million yr ago, copy numbers of centromeric repeats were largely reduced or diverged, and chromosomal distributions have changed, suggesting rapid evolution of centromeric repeats. We also detected variation in the distribution pattern of subtelomeric repeats in Phaseolus species. The FISH-based karyotyping system revealed that satellite repeats are actively and rapidly evolving, forming genomic features unique to individual common bean accessions and Phaseolus species.

  8. Endogenous pararetrovirus sequences associated with 24 nt small RNAs at the centromeres of Fritillaria imperialis L. (Liliaceae), a species with a giant genome

    Czech Academy of Sciences Publication Activity Database

    Becher, H.; Ma, L.; Kelly, L.J.; Kovařík, Aleš; Leitch, I. J.; Leitch, Andrew R.

    2014-01-01

    Roč. 80, č. 5 (2014), s. 823-833 ISSN 0960-7412 R&D Projects: GA ČR(CZ) GA13-10057S Institutional support: RVO:68081707 Keywords : pararetrovirus * Fritillaria imperialis * centromere Subject RIV: BO - Biophysics Impact factor: 5.972, year: 2014

  9. On-line sorting of human chromosomes by centromeric index, and identification of sorted populations by GTG-banding and fluorescent in situ hybridization

    NARCIS (Netherlands)

    Boschman, G. A.; Rens, W.; Manders, E.; van Oven, C.; Barendsen, G. W.; Aten, J. A.

    1990-01-01

    Using slit-scan flow cytometry, the shape of human metaphase chromosomes, as expressed in their centromeric index (CI), and the DNA content of the chromosomes have been used as parameters in bivariate flow karyotyping. The resolution of the DNA vs CI flow karyogram of the larger chromosomes up to

  10. Lack of independent prognostic and predictive value of centromere 17 copy number changes in breast cancer patients with known HER2 and TOP2A status

    DEFF Research Database (Denmark)

    Nielsen, Kirsten Vang; Ejlertsen, Bent; Møller, Susanne

    2011-01-01

    hybridization (FISH) with centromere 17 (CEN-17) and TOP2A was performed on 120 normal breast specimens. The diploid CEN-17 copy number was reduced from the expected two signals in whole nuclei to an average of 1.68 signals per nucleus in cut sections of normal breast. Ploidy levels determined in normal breast...

  11. Pleiotropic roles of Clostridium difficile sin locus

    Science.gov (United States)

    Ou, Junjun; Dupuy, Bruno

    2018-01-01

    Clostridium difficile is the primary cause of nosocomial diarrhea and pseudomembranous colitis. It produces dormant spores, which serve as an infectious vehicle responsible for transmission of the disease and persistence of the organism in the environment. In Bacillus subtilis, the sin locus coding SinR (113 aa) and SinI (57 aa) is responsible for sporulation inhibition. In B. subtilis, SinR mainly acts as a repressor of its target genes to control sporulation, biofilm formation, and autolysis. SinI is an inhibitor of SinR, so their interaction determines whether SinR can inhibit its target gene expression. The C. difficile genome carries two sinR homologs in the operon that we named sinR and sinR’, coding for SinR (112 aa) and SinR’ (105 aa), respectively. In this study, we constructed and characterized sin locus mutants in two different C. difficile strains R20291 and JIR8094, to decipher the locus’s role in C. difficile physiology. Transcriptome analysis of the sinRR’ mutants revealed their pleiotropic roles in controlling several pathways including sporulation, toxin production, and motility in C. difficile. Through various genetic and biochemical experiments, we have shown that SinR can regulate transcription of key regulators in these pathways, which includes sigD, spo0A, and codY. We have found that SinR’ acts as an antagonist to SinR by blocking its repressor activity. Using a hamster model, we have also demonstrated that the sin locus is needed for successful C. difficile infection. This study reveals the sin locus as a central link that connects the gene regulatory networks of sporulation, toxin production, and motility; three key pathways that are important for C. difficile pathogenesis. PMID:29529083

  12. The algebraic locus of Feynman integrals

    OpenAIRE

    Kol, Barak

    2016-01-01

    In the Symmetries of Feynman Integrals (SFI) approach, a diagram's parameter space is foliated by orbits of a Lie group associated with the diagram. SFI is related to the important methods of Integrations By Parts and of Differential Equations. It is shown that sometimes there exist a locus in parameter space where the set of SFI differential equations degenerates into an algebraic equation, thereby enabling a solution in terms of integrals associated with degenerations of the diagram. This i...

  13. Bipolar disorder: Evidence for a major locus

    Energy Technology Data Exchange (ETDEWEB)

    Spence, M.A.; Flodman, P.L. [Univ. of California, Irvine, CA (United States); Sadovnick, A.D.; Ameli, H. [Univ. of British Columbia, Vancouver (Canada)] [and others

    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.

  14. Expressed Centromere Specific Histone 3 (CENH3 Variants in Cultivated Triploid and Wild Diploid Bananas (Musa spp.

    Directory of Open Access Journals (Sweden)

    Kariuki S. Muiruri

    2017-06-01

    Full Text Available Centromeres are specified by a centromere specific histone 3 (CENH3 protein, which exists in a complex environment, interacting with conserved proteins and rapidly evolving satellite DNA sequences. The interactions may become more challenging if multiple CENH3 versions are introduced into the zygote as this can affect post-zygotic mitosis and ultimately sexual reproduction. Here, we characterize CENH3 variant transcripts expressed in cultivated triploid and wild diploid progenitor bananas. We describe both splice- and allelic-[Single Nucleotide Polymorphisms (SNP] variants and their effects on the predicted secondary structures of protein. Expressed CENH3 transcripts from six banana genotypes were characterized and clustered into three groups (MusaCENH-1A, MusaCENH-1B, and MusaCENH-2 based on similarity. The CENH3 groups differed with SNPs as well as presence of indels resulting from retained and/or skipped exons. The CENH3 transcripts from different banana genotypes were spliced in either 7/6, 5/4 or 6/5 exons/introns. The 7/6 and the 5/4 exon/intron structures were found in both diploids and triploids, however, 7/6 was most predominant. The 6/5 exon/introns structure was a result of failure of the 7/6 to splice correctly. The various transcripts obtained were predicted to encode highly variable N-terminal tails and a relatively conserved C-terminal histone fold domain (HFD. The SNPs were predicted in some cases to affect the secondary structure of protein by lengthening or shorting the affected domains. Sequencing of banana CENH3 transcripts predicts SNP variations that affect amino acid sequences and alternatively spliced transcripts. Most of these changes affect the N-terminal tail of CENH3.

  15. Two structurally distinct inhibitors of glycogen synthase kinase 3 induced centromere positive micronuclei in human lymphoblastoid TK6 cells.

    Science.gov (United States)

    Mishima, Masayuki; Tanaka, Kenji; Takeiri, Akira; Harada, Asako; Kubo, Chiyomi; Sone, Sachiko; Nishimura, Yoshikazu; Tachibana, Yukako; Okazaki, Makoto

    2008-08-25

    Glycogen synthase kinase 3 (GSK3) is an attractive novel pharmacological target. Inhibition of GSK3 is recently regarded as one of the viable approaches to therapy for Alzheimer's disease, cancer, diabetes mellitus, osteoporosis, and bipolar mood disorder. Here, we have investigated the aneugenic potential of two potent and highly specific inhibitors of GSK3 by using an in vitro micronucleus test with human lymphoblastoid TK6 cells. One inhibitor was a newly synthesized maleimide derivative and the other was a previously known aminopyrimidine derivative. Both compounds elicited statistically significant and concentration-dependent increases in micronucleated cells. One hundred micronuclei (MN) of each were analyzed using centromeric DNA staining with fluorescence in situ hybridization. Both the two structurally distinct compounds induced centromere-positive micronuclei (CMN). Calculated from the frequency of MN cells and the percentage of CMN, CMN cell incidence after treatment with the maleimide compound at 1.2 microM, 2.4 microM, and 4.8 microM was 11.6, 27.7, and 56.3 per 1000 cells, respectively; the negative control was 4.5. CMN cell incidence after the treatment with the aminopyrimidine compound at 1.8 microM, 3.6 microM, and 5.4 microM was 6.7, 9.8 and 17.2 per 1000 cells, respectively. Both compounds exhibited concentration-dependent increase in the number of mitotic cells. The frequency of CMN cells correlated well with mitotic cell incidence after treatment with either compound. Furthermore, both inhibitors induced abnormal mitotic cells with asymmetric mitotic spindles and lagging anaphase chromosomes. These results lend further support to the hypothesis that the inhibition of GSK3 activity affects microtubule function and exhibits an aneugenic mode of action.

  16. Mapping of Mcs30, a new mammary carcinoma susceptibility quantitative trait locus (QTL30 on rat chromosome 12: identification of fry as a candidate Mcs gene.

    Directory of Open Access Journals (Sweden)

    Xuefeng Ren

    Full Text Available 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.

  17. Locus of control and online learning

    Directory of Open Access Journals (Sweden)

    Suretha Esterhuysen

    2004-10-01

    Full Text Available The integration of online learning in university courses is considered to be both inevitable and necessary. Thus there is an increasing need to raise awareness among educators and course designers about the critical issues impacting on online learning. The aim of this study, therefore, was to assess the differences between two groups of first-year Business Sciences learners (online and conventional learners in terms of biographic and demographic characteristics and locus of control. The study population consisted of 586 first-year learners of whom 185 completed the Locus of Control Inventory (LCI. The results show that the two groups of learners do not differ statistically significantly from each other with respect to locus of control. The findings and their implications are also discussed. Opsomming Die integrasie van aanlyn-leer in universiteitskursusse word beskou as sowel onafwendbaar as noodsaaklik. Daar is dus ’n toenemende behoefte om bewustheid onder opvoedkundiges en kursusontwerpers te kweek oor die kritiese aspekte wat ’n impak op aanlyn-leer het (Morgan, 1996. Daarom was die doel van hierdie ondersoek om die verskille tussen twee groepe eerstejaarleerders in Bestuurs- en Ekonomiese Wetenskap (aanlyn en konvensionele leerders te bepaal ten opsigte van biografiese en demografiese eienskappe en lokus van beheer. Die populasie het bestaan uit 586 eerstejaarleerders waarvan 185 die Lokus van Beheer Vraelys voltooi het. Die resultate toon dat die twee groepe leerders nie statisties beduidend van mekaar verskil het met betrekking tot lokus van beheer nie. Die bevindinge en implikasies word ook bespreek.

  18. Designing Epigenome Editors: Considerations of Biochemical and Locus Specificities.

    Science.gov (United States)

    Sen, Dilara; Keung, Albert J

    2018-01-01

    The advent of locus-specific protein recruitment technologies has enabled a new class of studies in chromatin biology. Epigenome editors enable biochemical modifications of chromatin at almost any specific endogenous locus. Their locus specificity unlocks unique information including the functional roles of distinct modifications at specific genomic loci. Given the growing interest in using these tools for biological and translational studies, there are many specific design considerations depending on the scientific question or clinical need. Here we present and discuss important design considerations and challenges regarding the biochemical and locus specificities of epigenome editors. These include how to account for the complex biochemical diversity of chromatin; control for potential interdependency of epigenome editors and their resultant modifications; avoid sequestration effects; quantify the locus specificity of epigenome editors; and improve locus specificity by considering concentration, affinity, avidity, and sequestration effects.

  19. Cut Locus Construction using Deformable Simplicial Complexes

    DEFF Research Database (Denmark)

    Misztal, Marek Krzysztof; Bærentzen, Jakob Andreas; Anton, François

    2011-01-01

    In this paper we present a method for appproximating cut loci for a given point p on Riemannian 2D manifolds, closely related to the notion of Voronoi diagrams. Our method finds the cut locus by advecting a front of points equally distant from p along the geodesics originating at p and finding...... the domain to have disk topology. We test our method for tori of revolution and compare our results to the benchmark ones from [2]. The method, however, is generic and can be easily adapted to construct cut loci for other manifolds of genera other than 1....

  20. Relationships between locus of control and paranormal beliefs.

    Science.gov (United States)

    Newby, Robert W; Davis, Jessica Boyette

    2004-06-01

    The present study investigated the associations between scores on paranormal beliefs, locus of control, and certain psychological processes such as affect and cognitions as measured by the Linguistic Inquiry and Word Count. Analysis yielded significant correlations between scores on Locus of Control and two subscales of Tobacyk's (1988) Revised Paranormal Beliefs Scale, New Age Philosophy and Traditional Paranormal Beliefs. A step-wise multiple regression analysis indicated that Locus of Control was significantly related to New Age Philosophy. Other correlations were found between Tobacyk's subscales, Locus of Control, and three processes measured by the Linguistic Inquiry and Word Count.

  1. Impact of locus of control on health message effectiveness.

    Science.gov (United States)

    Kong, Ying; Shen, Fuyuan

    2011-10-01

    This article examined how individuals' locus of control might moderate the effect of health message frames. An experiment was conducted whereby participants read either individual- or social-responsibility message frames after their locus of control was primed. Results indicated that messages presented in individual-responsibility frames were more persuasive when people were primed with internal locus of control, whereas social-responsibility framed appeals were more persuasive when people were primed with external locus of control. These results were found for individuals in both high and low cognitive load conditions. Theoretical and practical implications of the findings are discussed.

  2. Novel ZBTB24 Mutation Associated with Immunodeficiency, Centromere Instability, and Facial Anomalies Type-2 Syndrome Identified in a Patient with Very Early Onset Inflammatory Bowel Disease.

    Science.gov (United States)

    Conrad, Máire A; Dawany, Noor; Sullivan, Kathleen E; Devoto, Marcella; Kelsen, Judith R

    2017-12-01

    Very early onset inflammatory bowel disease, diagnosed in children ≤5 years old, can be the initial presentation of some primary immunodeficiencies. In this study, we describe a 17-month-old boy with recurrent infections, growth failure, facial anomalies, and inflammatory bowel disease. Immune evaluation, whole-exome sequencing, karyotyping, and methylation array were performed to evaluate the child's constellation of symptoms and examination findings. Whole-exome sequencing revealed that the child was homozygous for a novel variant in ZBTB24, the gene associated with immunodeficiency, centromere instability, and facial anomalies type-2 syndrome. This describes the first case of inflammatory bowel disease associated with immunodeficiency, centromere instability, and facial anomalies type-2 syndrome in a child with a novel disease-causing mutation in ZBTB24 found on whole-exome sequencing.

  3. Locus - ASTRA | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available switchLanguage; BLAST Search Image Search Home About Archive Update History Data ...URL: ftp://ftp.biosciencedbc.jp/archive/astra/LATEST/astra_locus.zip File size: 887 KB Simple search URL htt...icing type (ex. cassette) About This Database Database Description Download License Update History of This Database Site Policy | Contact Us Locus - ASTRA | LSDB Archive ...

  4. Is this Red Spot the Blue Spot (locus ceruleum)?

    Energy Technology Data Exchange (ETDEWEB)

    Choe, Won Sick; Lee, Yu Kyung; Lee, Min Kyung; Hwang, Kyung Hoon [Gachon University Gil Hospital, Incheon (Korea, Republic of)

    2010-06-15

    The authors report brain images of 18F-FDG-PET in a case of schizophrenia. The images showed strikingly increased bilateral uptake in the locus ceruleum. The locus ceruleum is called the blue spot and known to be a center of the norepinephrinergic system.

  5. Metacognition: As a Predictor of One's Academic Locus of Control

    Science.gov (United States)

    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 correlations and…

  6. Personality and Locus of Control among School Children

    Science.gov (United States)

    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…

  7. Physical Attractiveness, Locus of Control, Sex Role, and Conversational Assertiveness.

    Science.gov (United States)

    Campbell, Keith F.; And Others

    1990-01-01

    Analyzes the relationship among physical attractiveness, locus of control, sex role orientation, and assertiveness in undergraduate students. Reviews videotapes of mixed-sex student groups engaged in discussion. Finds an internal locus of control positively correlated with assertiveness. Uses a behavioral measure of assertiveness rather than…

  8. Locus of control and investment in risky assets

    NARCIS (Netherlands)

    Salamanca Acosta, N.; de Grip, A.; Fouarge, D.; Montizaan, R.M.

    2013-01-01

    Using representative household panel data, we show that the investment behavior of households is related to the economic locus of control of household heads. A household’s internal locus of control in economic issues is positively related to its decision to hold risky assets as well as its share of

  9. Locus of control and investment in risky assets

    NARCIS (Netherlands)

    Salamanca, N.; de Grip, A.; Fouarge, D.; Montizaan, R.M.

    2013-01-01

    Using representative household panel data, we show that the investment behavior of households is related to the economic locus of control of household heads. A household's internal locus of control in economic issues is positively related to its decision to hold risky assets as well as its share of

  10. Is this Red Spot the Blue Spot (locus ceruleum)?

    International Nuclear Information System (INIS)

    Choe, Won Sick; Lee, Yu Kyung; Lee, Min Kyung; Hwang, Kyung Hoon

    2010-01-01

    The authors report brain images of 18F-FDG-PET in a case of schizophrenia. The images showed strikingly increased bilateral uptake in the locus ceruleum. The locus ceruleum is called the blue spot and known to be a center of the norepinephrinergic system.

  11. Escala de Locus de controle ELCO/TELEBRÁS Scale of Locus of control - ELCO

    Directory of Open Access Journals (Sweden)

    Luiz Pasquali

    1998-01-01

    Full Text Available Com base na teoria de Rotter e Escala de Levenson foi elaborada uma escala de Locus de Controle Organizacional (ELCO, composta por 28 itens. A escala foi validada com uma amostra de 350 empregados do Sistema Telebrás. Verificou-se a presença dos 2 fatores previstos na teoria, a saber: internalidade e externalidade, aparecendo a escala de externalidade, com 18 itens, bem estruturada (alfa = 0.81 e a de internalidade, com 10 itens, deixando a desejar no que se refere à consistência interna (alfa = 0.66. Com os dados desta pesquisa foi feita também análise do Locus de Controle desses mesmos empregados. A constatação mais saliente foi a de que o nível de internalidade caiu com o aumento do nível escolar e o aumento da experiência profissional desses mesmos empregados. Estes resultados surpreendentes foram interpretados em termos da situação típica da empresa, que está passando por um período de transição, a saber: a passagem da condição de empresa estatal para empresa privada, o que seria motivo da perda de confiança dos empregados na própria competência, particularmente por parte daqueles com maior competência intelectual e maior experiência profissional. Fez-se igualmente reparos na qualidade psicométrica da escala e da própria teoria do Locus de controle, no sentido de que esta precisa ser melhor axiomatizada para possibilitar a elaboração de escalas mais precisas para a medida dos construtos que propõe.A scale with 28 items, the Organizational Locus of Control (ELCO, was built based on Rotter’s theory and Levenson’s scale. ELCO was validated on a sample of 350 employees of Telebrás, a governmental firm in Brazil. As foreseen from the theory, a principal-axis factoring showed the presence of the expected two factors, namely internal and external locus of control. The external locus of control factor, composed of 18 items, showed good internal consistency (alpha =.81 whereas the internal factor, with 10 items

  12. Health Locus of Control尺度開発の歴史(社会科学編)

    OpenAIRE

    吉田, 由美; Yumi, YOSHIDA; 千葉県立衛生短期大学(看護学); Chiba College of Health Science

    1994-01-01

    This article describes the origins history of Health Locus of Control scales. First, Rotter's social learing theory, which is the theoretical background of the Health Locus of Control construct, is outlined. The scale and research trends of Locus of Control concept, and those of Health Locus of Control concept which are based on Locus of Control, are then reviewed. Finally, Health Locus of Control is discussed with regard to the implications for health education.

  13. Condensin HEAT subunits required for DNA repair, kinetochore/centromere function and ploidy maintenance in fission yeast.

    Directory of Open Access Journals (Sweden)

    Xingya Xu

    Full Text Available Condensin, a central player in eukaryotic chromosomal dynamics, contains five evolutionarily-conserved subunits. Two SMC (structural maintenance of chromosomes subunits contain ATPase, hinge, and coiled-coil domains. One non-SMC subunit is similar to bacterial kleisin, and two other non-SMC subunits contain HEAT (similar to armadillo repeats. Here we report isolation and characterization of 21 fission yeast (Schizosaccharomyces pombe mutants for three non-SMC subunits, created using error-prone mutagenesis that resulted in single-amino acid substitutions. Beside condensation, segregation, and DNA repair defects, similar to those observed in previously isolated SMC and cnd2 mutants, novel phenotypes were observed for mutants of HEAT-repeats containing Cnd1 and Cnd3 subunits. cnd3-L269P is hypersensitive to the microtubule poison, thiabendazole, revealing defects in kinetochore/centromere and spindle assembly checkpoints. Three cnd1 and three cnd3 mutants increased cell size and doubled DNA content, thereby eliminating the haploid state. Five of these mutations reside in helix B of HEAT repeats. Two non-SMC condensin subunits, Cnd1 and Cnd3, are thus implicated in ploidy maintenance.

  14. Development of a YAC contig covering the minimal region of a CSNB1 locus in Xp11

    Energy Technology Data Exchange (ETDEWEB)

    Boycott, K.M.; Gratton, K.J.; Moore, B.J. [Univ. of Calgary (Canada)] [and others

    1994-09-01

    X-linked congenital stationary night blindness (CSNB1) is an eye disorder that includes impairment of night vision, reduced visual acuity and, in some cases, myopia and congenital nystagmus. Electroretinography reveals a marked reduction of the b-wave in affected individuals suggesting that X-linked CSNB is due to a molecular defect in the bipolar layer of the retina. Based on our studies of a large four generation family with X-linked CSNB, a CSNB1 locus was mapped to a 4-5 cM region at Xp11.23-Xp11.22 bounded telomerically by DXS426 and centromerically by DXS988. Using a panel of radiation and conventional somatic cell hybrids, a detailed map of new and published STSs has been generated for the minimal region of CSNB1. PCR primer pairs for STSs has been generated for the minimal region of CSNB1. PCR primer pairs for twenty-five STSs, including eleven end-clones, were used to isolate YAC clones from CEPH, mega-CEPH, and X chromosome-specific YAC libraries. In total, fifty-two YACs were characterized for STS overlaps and assembled to provide a minimum of 3 Mb of physical coverage in the region between DXS426 and DXS988. Five gaps proximal to SYP are still to be closed. Our physical map suggests the following gene order: Xpter-OTAL1-GF1-DXS1011E-MG81-HUMCRAS2P-SYP-Xcen. STS analysis of the YACs revealed three subregions of the physical map which appear to be particularly susceptible to internal deletions and end-clone analysis demonstrated chimerism in six of seventeen YACs. A physical map of Xp11.23-Xp11.22 will provide a resource for the isolation of candidate genes for the X-linked CSNB gene which maps to this region.

  15. EL LOCUS DE DISTRIBUCION COMO COROLARIO DEL LOCUS DE CONTROL (THE LOCUS OF DISTRIBUTION AS A COROLLARY TO THE LOCUS OF CONTROL

    Directory of Open Access Journals (Sweden)

    Mayoral Luisa

    2009-08-01

    Full Text Available Resumen: Este es un artículo científico acerca del Locus de Distribución, surgido de un estudio realizado con una población de docentes y alumnos universitarios. Respecto de los primeros, se ha indagado acerca de las atribuciones que se realizaban en torno a las recompensas y sanciones, que ellos distribuían a sus alumnos.Respecto de los segundos, se ha buscado determinar la valoración que estos realizaban de sus profesores, en términos de aquellas atribuciones. Para ello, se utilizaron dos paradigmas clásicamente empleados para verificar la existencia de una norma: el paradigma de la autopresentación (docentes, y el paradigma de los j uicios (alumnos. La cuestión planteada fue determinar si en el caso de los comportamientos distributivos de refuerzos, las causas se atribuían a variables externas -en particular a los receptores de esos refuerzos- y si esas formas de atribución eran conocidas y valoradas o no, por los alumnos. De los resultados, surgió la confirmación de nuestra hipótesis de explicaciones externas en materia de comportamientos distributivos de sanciones en el ámbito de la docencia y la valoración positiva de estas atribuciones por los alumnos.Abstract:This one is a scientific article brings over of the Locus of Distribution, arisen from a study realized with a population of teachers and university pupils. Respect of the first ones, it has been investigated brings over of the attributions that were concerning around the reinforcements which they were distributing to pupils. Respect of the second ones, one has sought to determine the valuation that these realized of the teachers, in terms of those attributions. For it, two paradigms were in use classic used to check the existence of a norm: the paradigm of the auto-presentation (teachers, and the paradigm of the judgments (pupils The raised question was to determine if in case of the distributive behaviours of reinforcements, the reasons were assuming to external

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

    Science.gov (United States)

    Turnipseed, David L; Bacon, Calvin M

    2009-12-01

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

  17. Autism, fever, epigenetics and the locus coeruleus.

    Science.gov (United States)

    Mehler, Mark F; Purpura, Dominick P

    2009-03-01

    Some children with autism spectrum disorders (ASD) exhibit improved behaviors and enhanced communication during febrile episodes. We hypothesize that febrigenesis and the behavioral-state changes associated with fever in autism depend upon selective normalization of key components of a functionally impaired locus coeruleus-noradrenergic (LC-NA) system. We posit that autistic behaviors result from developmental dysregulation of LC-NA system specification and neural network deployment and modulation linked to the core behavioral features of autism. Fever transiently restores the modulatory functions of the LC-NA system and ameliorates autistic behaviors. Fever-induced reversibility of autism suggests preserved functional integrity of widespread neural networks subserving the LC-NA system and specifically the subsystems involved in mediating the cognitive and behavioral repertoires compromised in ASD. Alterations of complex gene-environmental interactions and associated epigenetic mechanisms during seminal developmental critical periods are viewed as instrumental in LC-NA dysregulation as emphasized by the timing and severity of prenatal maternal stressors on autism prevalence. Our hypothesis has implications for a rational approach to further interrogate the interdisciplinary etiology of ASD and for designing novel biological detection systems and therapeutic agents that target the LC-NA system's diverse network of pre- and postsynaptic receptors, intracellular signaling pathways and dynamic epigenetic remodeling processes involved in their regulation and functional plasticity.

  18. Breakpoint of an inversion of chromosome 14 in a T-cell leukemia: sequences downstream of the immunoglobulin heavy chain locus are implicated in tumorigenesis

    International Nuclear Information System (INIS)

    Baer, R.; Heppell, A.; Taylor, A.M.R.; Rabbitts, P.H.; Boullier, B.; Rabbitts, T.H.

    1987-01-01

    T-cell tumors are characterized by inversions or translocations of chromosome 14. The breakpoints of these karyotypic abnormalities occur in chromosome bands 14q11 and 14q32 - the same bands in which the T-cell receptor (TCR) α-chain and immunoglobulin heavy chain genes have been mapped, respectively. Patients with ataxia-telangiectasia are particularly prone to development of T-cell chronic lymphocytic leukemia with such chromosomal abnormalities. The authors describe DNA rearrangements of the TCR α-chain gene in an ataxia-telangiectasia-associated leukemia containing both a normal and an inverted chromosome 14. The normal chromosome 14 has undergone a productive join of TCR α-chain variable (V/sub α/) and joining (J/sub α/) gene segments. The other allele of the TCR α-chain gene features a DNA rearrangement, about 50 kilobases from the TCR α-chain constant (C/sub α/) gene, that represents the breakpoint of the chromosome 14 inversion; this breakpoint is comprised of a TCR J/sub α/) segment (from 14q11) fused to sequences derived from 14q32 but on the centromeric side of C/sub μ/. These results imply that 14q32 sequences located at an undetermined distance downstream of immunoglobulin C/sub μ/ locus can contribute to the development of T-cell tumors

  19. A locus for isolated cataract on human Xp.

    Science.gov (United States)

    Francis, P J; Berry, V; Hardcastle, A J; Maher, E R; Moore, A T; Bhattacharya, S S

    2002-02-01

    To genetically map the gene causing isolated X linked cataract in a large European pedigree. Using the patient registers at Birmingham Women's Hospital, UK, we identified and examined 23 members of a four generation family with nuclear cataract. Four of six affected males also had complex congenital heart disease. Pedigree data were collated and leucocyte DNA extracted from venous blood. Linkage analysis by PCR based microsatellite marker genotyping was used to identify the disease locus and mutations within candidate genes screened by direct sequencing. The disease locus was genetically refined to chromosome Xp22, within a 3 cM linkage interval flanked by markers DXS9902 and DXS999 (Zmax=3.64 at theta=0 for marker DXS8036). This is the first report of a locus for isolated inherited cataract on the X chromosome. The disease interval lies within the Nance-Horan locus suggesting allelic heterogeneity. The apparent association with congenital cardiac anomalies suggests a possible new oculocardiac syndrome.

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

    Science.gov (United States)

    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. © The Author(s) 2015.

  1. 240 INFLUENCES OF PEER RELATIONS AND LOCUS OF ...

    African Journals Online (AJOL)

    Financial recklessness is a behavior that has far reaching negative .... between consumer financial knowledge, income and locus of control on financial ... Their interactions with their peers increased their internal motivations and thus helped.

  2. Emotional intelligence and locus of control of adult patients with ...

    African Journals Online (AJOL)

    2011-03-15

    Mar 15, 2011 ... Keywords: breast cancer, treatment, positive psychology, emotional intelligence, locus of control ... branches are organised in a hierarchy with perception of ..... Asian. Development Bank Knowledge Solutions [serial online].

  3. Detection and Automated Scoring of Dicentric Chromosomes in Nonstimulated Lymphocyte Prematurely Condensed Chromosomes After Telomere and Centromere Staining

    Energy Technology Data Exchange (ETDEWEB)

    M' kacher, Radhia [Laboratoire de Radiobiologie et Oncologie, Commissariat à l' Energie Atomique, Fontenay-aux-Roses (France); El Maalouf, Elie [Laboratoire de Radiobiologie et Oncologie, Commissariat à l' Energie Atomique, Fontenay-aux-Roses (France); Laboratoire Modélisation Intelligence Processus Systèmes (MIPS)–Groupe TIIM3D, Université de Haute-Alsace, Mulhouse (France); Terzoudi, Georgia [Laboratory of Radiobiology & Biodosimetry, National Center for Scientific Research Demokritos, Athens (Greece); Ricoul, Michelle [Laboratoire de Radiobiologie et Oncologie, Commissariat à l' Energie Atomique, Fontenay-aux-Roses (France); Heidingsfelder, Leonhard [MetaSystems, Altlussheim (Germany); Karachristou, Ionna [Laboratory of Radiobiology & Biodosimetry, National Center for Scientific Research Demokritos, Athens (Greece); Laplagne, Eric [Pole Concept, Paris (France); Hempel, William M. [Laboratoire de Radiobiologie et Oncologie, Commissariat à l' Energie Atomique, Fontenay-aux-Roses (France); Colicchio, Bruno; Dieterlen, Alain [Laboratoire Modélisation Intelligence Processus Systèmes (MIPS)–Groupe TIIM3D, Université de Haute-Alsace, Mulhouse (France); Pantelias, Gabriel [Laboratory of Radiobiology & Biodosimetry, National Center for Scientific Research Demokritos, Athens (Greece); Sabatier, Laure, E-mail: laure.sabatier@cea.fr [Laboratoire de Radiobiologie et Oncologie, Commissariat à l' Energie Atomique, Fontenay-aux-Roses (France)

    2015-03-01

    Purpose: To combine telomere and centromere (TC) staining of premature chromosome condensation (PCC) fusions to identify dicentrics, centric rings, and acentric chromosomes, making possible the realization of a dose–response curve and automation of the process. Methods and Materials: Blood samples from healthy donors were exposed to {sup 60}Co irradiation at varying doses up to 8 Gy, followed by a repair period of 8 hours. Premature chromosome condensation fusions were carried out, and TC staining using peptide nucleic acid probes was performed. Chromosomal aberration (CA) scoring was carried out manually and automatically using PCC-TCScore software, developed in our laboratory. Results: We successfully optimized the hybridization conditions and image capture parameters, to increase the sensitivity and effectiveness of CA scoring. Dicentrics, centric rings, and acentric chromosomes were rapidly and accurately detected, leading to a linear-quadratic dose–response curve by manual scoring at up to 8 Gy. Using PCC-TCScore software for automatic scoring, we were able to detect 95% of dicentrics and centric rings. Conclusion: The introduction of TC staining to the PCC fusion technique has made possible the rapid scoring of unstable CAs, including dicentrics, with a level of accuracy and ease not previously possible. This new approach can be used for biological dosimetry in radiation emergency medicine, where the rapid and accurate detection of dicentrics is a high priority using automated scoring. Because there is no culture time, this new approach can also be used for the follow-up of patients treated by genotoxic therapy, creating the possibility to perform the estimation of induced chromosomal aberrations immediately after the blood draw.

  4. LOCUS OF CONTROL AND JOB SATISFACTION: PSU EMPLOYEES

    Directory of Open Access Journals (Sweden)

    Lakshman Vijayashree

    2011-11-01

    Full Text Available Previous research studies have demonstrated that internal/external locus of control impacts jobsatisfaction. The present study thus aims to analyze type of locus of control and its relation with jobsatisfaction. The study will be of great help for organization to understand and know what type oflocus of control their employees has and how it has an impact on job satisfaction.The objectives of this study were: 1- To identify the type of Locus of Control (i.e. Internal orExternal present in Public Sector Units (PSU in Bangalore and 2- To analyze the impact of differenttype of Locus of Control on job satisfaction of PSU Employees. Further hypothesis was also set tocheck the relationship between locus of control and job satisfaction. In addition, the relationshipbetween different demographic factors was also examined. The tool used for this study was LocoInventory. The concept of locus of control by Levenson (1972 was used to develop Loco Inventory(Locus of Control in Organization Inventory. The survey used a questionnaire, which had thirty fivestatements which highlights the factors that determine the locus of control and job satisfaction levelof the employees. The Ratio, ANOVA, and Correlation analysis were used as statistical techniquesfor analysis.The results indicate that there is a positive correlation between internal locus of control and jobsatisfaction as well as between External (other locus of control and job satisfaction. And in case ofExternal (Chance locus of control and job satisfaction there exists partial positive correlation. As perthis study Job satisfaction level among the employees is also good as the mean is 17, which is closerto maximum scale value of 25. As per ANOVA table there is a significant variance betweeninternality and age as well as between externality (chance and age. There is no significantrelationship between internality and demographic factors like gender and education. There is nosignificant relationship between

  5. The relationship between locus of control and career advancement

    OpenAIRE

    2014-01-01

    M.Com. (Industrial Psychology) The objective which career of this study advancement is was to investigate the extent to contingent on the personality construct locus of control. In order to achieve this, empirical research was conducted in a South African organisation. A survey questionnaire measuring career advancement and locus of control was completed by 152 subjects. The hypothesis which was formulated was that people with higher rates of career advancement would be more internal and t...

  6. Analysis of the ABCA4 genomic locus in Stargardt disease

    DEFF Research Database (Denmark)

    Zernant, Jana; Xie, Yajing Angela; Ayuso, Carmen

    2014-01-01

    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....

  7. Science Study For A Low Cost Upper Atmosphere Sounder (LOCUS)

    Science.gov (United States)

    Gerber, D.; Swinyard, B. M.; Ellison, B. N.; Siddans, R.; Kerridge, B. J.; Plane, J. M. C.; Feng, W.

    2013-12-01

    We present the findings of an initial science study to define the spectral bands for the proposed Mesosphere / Lower Thermosphere (MLT) sounder LOCUS. The LOCUS mission (Fig 1) uses disruptive technologies to make key MLT species detectable globally by satellite remote sensing for the first time. This presentation summarises the technological and scientific foundation on which the current 4-band Terahertz (THz) and sub- millimetre wave (SMW) instrument configuration was conceived.

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

    Science.gov (United States)

    Durand, Guillermo; Lessard, Sabin

    2016-06-01

    We study a two-locus model of intersexual selection in a finite haploid population reproducing according to a discrete-time Moran model with a trait locus expressed in males and a preference locus expressed in females. We show that the probability of ultimate fixation of a single mutant allele for a male ornament introduced at random at the trait locus given any initial frequency state at the preference locus is increased by weak intersexual selection and recombination, weak or strong. Moreover, this probability exceeds the initial frequency of the mutant allele even in the case of a costly male ornament if intersexual selection is not too weak. On the other hand, the probability of ultimate fixation of a single mutant allele for a female preference towards a male ornament introduced at random at the preference locus is increased by weak intersexual selection and weak recombination if the female preference is not costly, and is strong enough in the case of a costly male ornament. The analysis relies on an extension of the ancestral recombination-selection graph for samples of haplotypes to take into account events of intersexual selection, while the symbolic calculation of the fixation probabilities is made possible in a reasonable time by an optimizing algorithm. Copyright © 2016 Elsevier Inc. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    Tienari, P.J. (National Public Health Institute, Helsinki (Finland) Univ. of Helsinki (Finland)); Terwilliger, J.D.; Ott, J. (Columbia Univ., New York (United States)); Palo, J. (Univ. of Helsinki (Finland)); Peltonen, L. (National Public Health Institute, Helsinki (Finland))

    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.

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

    Science.gov (United States)

    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. © Georg Thieme Verlag KG Stuttgart · New York.

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

    Science.gov (United States)

    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.

  12. DNA modification study of major depressive disorder: beyond locus-by-locus comparisons.

    Science.gov (United States)

    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

    2015-02-01

    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. 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. 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. 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. Copyright © 2015 Society of Biological Psychiatry. All rights reserved.

  13. The Cell Cycle Timing of Centromeric Chromatin Assembly in Drosophila Meiosis Is Distinct from Mitosis Yet Requires CAL1 and CENP-C

    Science.gov (United States)

    Gorgescu, Walter; Tang, Jonathan; Costes, Sylvain V.; Karpen, Gary H.

    2012-01-01

    CENP-A (CID in flies) is the histone H3 variant essential for centromere specification, kinetochore formation, and chromosome segregation during cell division. Recent studies have elucidated major cell cycle mechanisms and factors critical for CENP-A incorporation in mitosis, predominantly in cultured cells. However, we do not understand the roles, regulation, and cell cycle timing of CENP-A assembly in somatic tissues in multicellular organisms and in meiosis, the specialized cell division cycle that gives rise to haploid gametes. Here we investigate the timing and requirements for CID assembly in mitotic tissues and male and female meiosis in Drosophila melanogaster, using fixed and live imaging combined with genetic approaches. We find that CID assembly initiates at late telophase and continues during G1 phase in somatic tissues in the organism, later than the metaphase assembly observed in cultured cells. Furthermore, CID assembly occurs at two distinct cell cycle phases during male meiosis: prophase of meiosis I and after exit from meiosis II, in spermatids. CID assembly in prophase I is also conserved in female meiosis. Interestingly, we observe a novel decrease in CID levels after the end of meiosis I and before meiosis II, which correlates temporally with changes in kinetochore organization and orientation. We also demonstrate that CID is retained on mature sperm despite the gross chromatin remodeling that occurs during protamine exchange. Finally, we show that the centromere proteins CAL1 and CENP-C are both required for CID assembly in meiosis and normal progression through spermatogenesis. We conclude that the cell cycle timing of CID assembly in meiosis is different from mitosis and that the efficient propagation of CID through meiotic divisions and on sperm is likely to be important for centromere specification in the developing zygote. PMID:23300382

  14. Generation of an approximately 2.4 Mb human X centromere-based minichromosome by targeted telomere-associated chromosome fragmentation in DT40.

    Science.gov (United States)

    Mills, W; Critcher, R; Lee, C; Farr, C J

    1999-05-01

    A linear mammalian artificial chromosome (MAC) will require at least three types of functional element: a centromere, two telomeres and origins of replication. As yet, our understanding of these elements, as well as many other aspects of structure and organization which may be critical for a fully functional mammalian chromosome, remains poor. As a way of defining these various requirements, minichromosome reagents are being developed and analysed. Approaches for minichromosome generation fall into two broad categories: de novo assembly from candidate DNA sequences, or the fragmentation of an existing chromosome to reduce it to a minimal size. Here we describe the generation of a human minichromosome using the latter, top-down, approach. A human X chromosome, present in a DT40-human microcell hybrid, has been manipulated using homologous recombination and the targeted seeding of a de novo telomere. This strategy has generated a linear approximately 2.4 Mb human X centromere-based minichromosome capped by two artificially seeded telomeres: one immediately flanking the centromeric alpha-satellite DNA and the other targeted to the zinc finger gene ZXDA in Xp11.21. The chromosome retains an alpha-satellite domain of approximately 1. 8 Mb, a small array of gamma-satellite repeat ( approximately 40 kb) and approximately 400 kb of Xp proximal DNA sequence. The mitotic stability of this minichromosome has been examined, both in DT40 and following transfer into hamster and human cell lines. In all three backgrounds, the minichromosome is retained efficiently, but in the human and hamster microcell hybrids its copy number is poorly regulated. This approach of engineering well-defined chromosome reagents will allow key questions in MAC development (such as whether a lower size limit exists) to be addressed. In addition, the 2.4 Mb minichromosome described here has potential to be developed as a vector for gene delivery.

  15. Molecular characterization and chromosomal distribution of a species-specific transcribed centromeric satellite repeat from the olive fruit fly, Bactrocera oleae.

    Directory of Open Access Journals (Sweden)

    Konstantina T Tsoumani

    Full Text Available Satellite repetitive sequences that accumulate in the heterochromatin consist a large fraction of a genome and due to their properties are suggested to be implicated in centromere function. Current knowledge of heterochromatic regions of Bactrocera oleae genome, the major pest of the olive tree, is practically nonexistent. In our effort to explore the repetitive DNA portion of B. oleae genome, a novel satellite sequence designated BoR300 was isolated and cloned. The present study describes the genomic organization, abundance and chromosomal distribution of BoR300 which is organized in tandem, forming arrays of 298 bp-long monomers. Sequence analysis showed an AT content of 60.4%, a CENP-B like-motif and a high curvature value based on predictive models. Comparative analysis among randomly selected monomers demonstrated a high degree of sequence homogeneity (88%-97% of BoR300 repeats, which are present at approximately 3,000 copies per haploid genome accounting for about 0.28% of the total genomic DNA, based on two independent qPCR approaches. In addition, expression of the repeat was also confirmed through RT-PCR, by which BoR300 transcripts were detected in both sexes. Fluorescence in situ hybridization (FISH of BoR300 on mitotic metaphases and polytene chromosomes revealed signals to the centromeres of two out of the six chromosomes which indicated a chromosome-specific centromeric localization. Moreover, BoR300 is not conserved in the closely related Bactrocera species tested and it is also absent in other dipterans, but it's rather restricted to the B. oleae genome. This feature of species-specificity attributed to BoR300 satellite makes it a good candidate as an identification probe of the insect among its relatives at early development stages.

  16. DNA deformability changes of single base pair mutants within CDE binding sites in S. Cerevisiae centromere DNA correlate with measured chromosomal loss rates and CDE binding site symmetries

    Directory of Open Access Journals (Sweden)

    Marx Kenneth A

    2006-03-01

    Full Text Available Abstract Background The centromeres in yeast (S. cerevisiae are organized by short DNA sequences (125 bp on each chromosome consisting of 2 conserved elements: CDEI and CDEIII spaced by a CDEII region. CDEI and CDEIII are critical sequence specific protein binding sites necessary for correct centromere formation and following assembly with proteins, are positioned near each other on a specialized nucleosome. Hegemann et al. BioEssays 1993, 15: 451–460 reported single base DNA mutants within the critical CDEI and CDEIII binding sites on the centromere of chromosome 6 and quantitated centromere loss of function, which they measured as loss rates for the different chromosome 6 mutants during cell division. Olson et al. Proc Natl Acad Sci USA 1998, 95: 11163–11168 reported the use of protein-DNA crystallography data to produce a DNA dinucleotide protein deformability energetic scale (PD-scale that describes local DNA deformability by sequence specific binding proteins. We have used the PD-scale to investigate the DNA sequence dependence of the yeast chromosome 6 mutants' loss rate data. Each single base mutant changes 2 PD-scale values at that changed base position relative to the wild type. In this study, we have utilized these mutants to demonstrate a correlation between the change in DNA deformability of the CDEI and CDEIII core sites and the overall experimentally measured chromosome loss rates of the chromosome 6 mutants. Results In the CDE I and CDEIII core binding regions an increase in the magnitude of change in deformability of chromosome 6 single base mutants with respect to the wild type correlates to an increase in the measured chromosome loss rate. These correlations were found to be significant relative to 105 Monte Carlo randomizations of the dinucleotide PD-scale applied to the same calculation. A net loss of deformability also tends to increase the loss rate. Binding site position specific, 4 data-point correlations were also

  17. High-resolution meiotic and physical mapping of the Best`s vitelliform macular dystrophy (VMD2) locus to pericentromeric chromosome 11

    Energy Technology Data Exchange (ETDEWEB)

    Weber, B.H.F.; Vogt, G. [Institut fuer Humangenetik, Wuerzburg (Germany); Walker, D. [UBC, Vancouver (Canada)] [and others

    1994-09-01

    Vitelliform macular dystrophy, also known as Best`s disease, is a juvenile-onset macular degeneration with autosomal dominant inheritance. It is characterized by well-demarcated accumulation of lipofuscin-like material within and beneath the retinal pigment epithelium (RPE) and classically results in an egg yolk-like appearance of the macula. Typically, carriers of the disease gene show a specific electrophysiological sign which can be detected by electrooculography (EOG). The EOG measures a standing potential between the cornea and the retina which is primarily generated by the RPE. The histopathological findings as well as the EOG abnormalities suggest that Best`s disease is a generalized disorder of the RPE. The basic biochemical defect is still unknown. As a first step in the positional cloning of the defective gene, the Best`s disease locus was mapped to chromosome 11 between markers at D11S871 and INT2. Subsequently, his region was refined to a 3.7 cM interval flanked by loci D11S903 and PYGM. To further narrow the D11S903-PYGM interval and to obtain an estimate of the physical size of the minimal candidate region, we used a combination of high-resolution PCR hybrid mapping and analysis of recombinant Best`s disease chromosomes. We identified six markers from within the D11S903-PYGM interval that show no recombination with the defective gene in three multigeneration Best`s disease pedigrees. Our hybrid panel localizes these markers on either side of the centromere on chromosome 11. The closest markers flanking the disease gene are at D11S986 in band p12-11.22 and at D11S480 in band q13.2-13.3. Our study demonstrates that the physical size of the Best`s disease region is exceedingly larger than was previously estimated from the genetic data due to the proximity of the defective gene to the centromere of chromosome 11.

  18. Transcriptional Response of Human Neurospheres to Helper-Dependent CAV-2 Vectors Involves the Modulation of DNA Damage Response, Microtubule and Centromere Gene Groups.

    Directory of Open Access Journals (Sweden)

    Stefania Piersanti

    Full Text Available Brain gene transfer using viral vectors will likely become a therapeutic option for several disorders. Helper-dependent (HD canine adenovirus type 2 vectors (CAV-2 are well suited for this goal. These vectors are poorly immunogenic, efficiently transduce neurons, are retrogradely transported to afferent structures in the brain and lead to long-term transgene expression. CAV-2 vectors are being exploited to unravel behavior, cognition, neural networks, axonal transport and therapy for orphan diseases. With the goal of better understanding and characterizing HD-CAV-2 for brain therapy, we analyzed the transcriptomic modulation induced by HD-CAV-2 in human differentiated neurospheres derived from midbrain progenitors. This 3D model system mimics several aspects of the dynamic nature of human brain. We found that differentiated neurospheres are readily transduced by HD-CAV-2 and that transduction generates two main transcriptional responses: a DNA damage response and alteration of centromeric and microtubule probes. Future investigations on the biochemistry of processes highlighted by probe modulations will help defining the implication of HD-CAV-2 and CAR receptor binding in enchaining these functional pathways. We suggest here that the modulation of DNA damage genes is related to viral DNA, while the alteration of centromeric and microtubule probes is possibly enchained by the interaction of the HD-CAV-2 fibre with CAR.

  19. Dicentric chromosome aberration analysis using giemsa and centromere specific fluorescence in-situ hybridization for biological dosimetry: An inter- and intra-laboratory comparison in Indian laboratories

    International Nuclear Information System (INIS)

    Bhavani, M.; Tamizh Selvan, G.; Kaur, Harpreet; Adhikari, J.S.; Vijayalakshmi, J.; Venkatachalam, P.; Chaudhury, N.K.

    2014-01-01

    To facilitate efficient handling of large samples, an attempt towards networking of laboratories in India for biological dosimetry was carried out. Human peripheral blood samples were exposed to 60 Co γ-radiation for ten different doses (0–5 Gy) at a dose rate of 0.7 and 2 Gy/min. The chromosomal aberrations (CA) were scored in Giemsa-stained and fluorescence in-situ hybridization with centromere-specific probes. No significant difference (p>0.05) was observed in the CA yield for given doses except 4 and 5 Gy, between the laboratories, among the scorers and also staining methods adapted suggest the reliability and validates the inter-lab comparisons exercise for triage applications. - Highlights: • This is the first report from India on Networking for Biological Dosimetry preparedness using dicentric chromosomal (DC) aberration assay. • There is no significant difference in the in vitro dose response curve (Slope, Intercept, Curvature) constructed among the two labs. • No significant variation in the scoring of DC aberrations between the scorers irrespective of labs. • The DC results obtained by the labs from the Giemsa stained metaphase preparations were confirmed with centromere specific-FISH for further reliability and validity

  20. Mutation at the Human D1S80 Minisatellite Locus

    Directory of Open Access Journals (Sweden)

    Kuppareddi Balamurugan

    2012-01-01

    Full Text Available Little is known about the general biology of minisatellites. The purpose of this study is to examine repeat mutations from the D1S80 minisatellite locus by sequence analysis to elucidate the mutational process at this locus. This is a highly polymorphic minisatellite locus, located in the subtelomeric region of chromosome 1. We have analyzed 90,000 human germline transmission events and found seven (7 mutations at this locus. The D1S80 alleles of the parentage trio, the child, mother, and the alleged father were sequenced and the origin of the mutation was determined. Using American Association of Blood Banks (AABB guidelines, we found a male mutation rate of 1.04×10-4 and a female mutation rate of 5.18×10-5 with an overall mutation rate of approximately 7.77×10-5. Also, in this study, we found that the identified mutations are in close proximity to the center of the repeat array rather than at the ends of the repeat array. Several studies have examined the mutational mechanisms of the minisatellites according to infinite allele model (IAM and the one-step stepwise mutation model (SMM. In this study, we found that this locus fits into the one-step mutation model (SMM mechanism in six out of seven instances similar to STR loci.

  1. Inferring Demographic History Using Two-Locus Statistics.

    Science.gov (United States)

    Ragsdale, Aaron P; Gutenkunst, Ryan N

    2017-06-01

    Population demographic history may be learned from contemporary genetic variation data. Methods based on aggregating the statistics of many single loci into an allele frequency spectrum (AFS) have proven powerful, but such methods ignore potentially informative patterns of linkage disequilibrium (LD) between neighboring loci. To leverage such patterns, we developed a composite-likelihood framework for inferring demographic history from aggregated statistics of pairs of loci. Using this framework, we show that two-locus statistics are more sensitive to demographic history than single-locus statistics such as the AFS. In particular, two-locus statistics escape the notorious confounding of depth and duration of a bottleneck, and they provide a means to estimate effective population size based on the recombination rather than mutation rate. We applied our approach to a Zambian population of Drosophila melanogaster Notably, using both single- and two-locus statistics, we inferred a substantially lower ancestral effective population size than previous works and did not infer a bottleneck history. Together, our results demonstrate the broad potential for two-locus statistics to enable powerful population genetic inference. Copyright © 2017 by the Genetics Society of America.

  2. Locus-specific view of flax domestication history

    Science.gov (United States)

    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. PMID:22408732

  3. [Observation and analysis on mutation of routine STR locus].

    Science.gov (United States)

    Li, Qiu-yang; Feng, Wei-jun; Yang, Qin-gen

    2005-05-01

    To observe and analyze the characteristic of mutation at STR locus. 27 mutant genes observed in 1211 paternity testing cases were checked by PAGE-silver stained and PowerPlex 16 System Kit and validated by sequencing. Mutant genes locate on 15 loci. The pattern of mutation was accord with stepwise mutation model. The mutation ratio of male-to-female was 8:1 and correlated to the age of father. Mutation rate is correlated to the geometric mean of the number of homogeneous repeats of locus. The higher the mean, the higher the mutation rate. These loci are not so appropriate for use in paternity testing.

  4. Hydroxysteroid (17β)-dehydrogenase 1-deficient female mice present with normal puberty onset but are severely subfertile due to a defect in luteinization and progesterone production.

    Science.gov (United States)

    Hakkarainen, Janne; Jokela, Heli; Pakarinen, Pirjo; Heikelä, Hanna; Kätkänaho, Laura; Vandenput, Liesbeth; Ohlsson, Claes; Zhang, Fu-Ping; Poutanen, Matti

    2015-09-01

    Hydroxysteroid (17β)-dehydrogenase type 1 (HSD17B1) catalyzes the conversion of low active 17-ketosteroids, androstenedione (A-dione) and estrone (E1) to highly active 17-hydroxysteroids, testosterone (T) and E2, respectively. In this study, the importance of HSD17B1 in ovarian estrogen production was determined using Hsd17b1 knockout (HSD17B1KO) mice. In these mice, the ovarian HSD17B enzyme activity was markedly reduced, indicating a central role of HSD17B1 in ovarian physiology. The lack of Hsd17b activity resulted in increased ovarian E1:E2 and A-dione:T ratios, but we also observed reduced progesterone concentration in HSD17B1KO ovaries. Accordingly with the altered steroid production, altered expression of Star, Cyp11a1, Lhcgr, Hsd17b7, and especially Cyp17a1 was observed. The ovaries of HSD17B1KO mice presented with all stages of folliculogenesis, while the corpus luteum structure was less defined and number reduced. Surprisingly, bundles of large granular cells of unknown origin appeared in the stroma of the KO ovaries. The HSD17B1KO mice presented with severe subfertility and failed to initiate pseudopregnancy. However, the HSD17B1KO females presented with normal estrous cycle defined by vaginal smears and normal puberty appearance. This study indicates that HSD17B1 is a key enzyme in ovarian steroidogenesis and has a novel function in initiation and stabilization of pregnancy. © FASEB.

  5. Heterotic trait locus (HTL) mapping identifies intra-locus interactions that underlie reproductive hybrid vigor in Sorghum bicolor.

    Science.gov (United States)

    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.

  6. Locus of Control and Technology Adoption in Developing Country Agriculture

    DEFF Research Database (Denmark)

    Abay, Kibrom Araya; Blalock, Garrick; Berhane, Guush

    2017-01-01

    and psychological explanations for the low rates of adoption of profitable agricultural technologies in Sub-Saharan Africa. Our results highlight that improving farmers’ non-cognitive skills (locus of control) may facilitate technology adoption and agricultural transformation. More generally, the results suggest...

  7. AUTOMATIC GENERATION OF ROOT LOCUS PLOTS FOR LINEAR ...

    African Journals Online (AJOL)

    Design and analysis of control systems often become difficult due to the complexity of the system model and the design techniques involved. This paper presents the development of a Tools Box in Microsoft Excel for control engineer that uses root locus as a time domain technique for system design and analysis. The Tool ...

  8. Male-pattern baldness susceptibility locus at 20p11.

    NARCIS (Netherlands)

    Richards, J.B.; Yuan, X.; Geller, F.; Waterworth, D.; Bataille, V.; Glass, D.; Song, K.; Waeber, G.; Vollenweider, P.; Aben, K.K.H.; Kiemeney, L.A.L.M.; Walters, B.; Soranzo, N.; Thorsteinsdottir, U.; Kong, A.; Rafnar, T.; Deloukas, P.; Sulem, P.; Stefansson, H.; Stefansson, K.; Spector, T.D.; Mooser, V.

    2008-01-01

    We conducted a genome-wide association study for androgenic alopecia in 1,125 men and identified a newly associated locus at chromosome 20p11.22, confirmed in three independent cohorts (n = 1,650; OR = 1.60, P = 1.1 x 10(-14) for rs1160312). The one man in seven who harbors risk alleles at both

  9. (PLWHA): influence of social support, self-esteem, health locus

    African Journals Online (AJOL)

    Coping among people living with HIV/AIDS (PLWHA): influence of social support, self-esteem, health locus of control and gender. ... approach, social support should be in the front burner, society should be sensitized to the importance of social support that is culturally appropriate and behaviour modification focused.

  10. Relationship Among Achievement Motivation, Self-Esteem, Locus of ...

    African Journals Online (AJOL)

    The thrust of the study was to examine the relationship among achievement motivation, self-esteem, locus of control and academic performance of university students in a Nigerian University. The purpose was to determine the extent university student\\'s academic performance was influenced by these criterion variables.

  11. Locus of control and learning strategies as predictors of academic ...

    African Journals Online (AJOL)

    The aim of the research was to determine the relationships which exist between academic success, learning strategies and locus of control. In order to achieve this aim a small-scale quantitative study, utilising two inventories, was done. The first measuring instrument is the Learning and Study Strategies Inventory, which is ...

  12. Y-Chromosome short tandem repeat, typing technology, locus ...

    African Journals Online (AJOL)

    Aghomotsegin

    2015-07-08

    Jul 8, 2015 ... Y-Chromosome short tandem repeat, typing technology, locus information and allele frequency in different population: A review. Muhanned Abdulhasan Kareem1, Ameera Omran Hussein2 and Imad Hadi Hameed2*. 1Babylon University, Centre of Environmental Research, Hilla City, Iraq. 2Department of ...

  13. Influence of Locus Control on Real and Perceived Relationships ...

    African Journals Online (AJOL)

    They included the Nowicki-Strickland Internal – External Locus of Control Scale for children by Nowicki and Strickland (1973) and Emotional – Social Loneliness Inventory by Vincenzi and Grabosky, (1987). A cross sectional survey design was used while regression analysis and multivariate statistics were used in data ...

  14. Screening for genomic rearrangements at BRCA1 locus in Iranian ...

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... Home; Journals; Journal of Genetics; Volume 92; Issue 1. Screening for genomic rearrangements at BRCA1 locus in Iranian women with breast cancer using multiplex ligation-dependent probe amplification. Vahid R. Yassaee Babak Emamalizadeh Mir Davood Omrani. Research Note Volume 92 Issue 1 ...

  15. Gender, Age and Locus of Control as Correlates of Remedial ...

    African Journals Online (AJOL)

    Gender, Age and Locus of Control as Correlates of Remedial Learners' Attitude towards English Language. ... These findings have far-reaching implications for adult and non-formal education practitioners and other stakeholders interested in improving the lots of several learners out there, in English language. Keywords: ...

  16. Sex Differences in Locus of Control, Helplessness, Hopelessness, and Depression.

    Science.gov (United States)

    Kolotkin, Richard A.; And Others

    This experiment investigated: (1) relationships among locus of control, attributional style, and depression; (2) if a depressogenic attributional style could be empirically isolated; and (3) if reliable relationships existed between attribution and depression when depression was operationalized using different instruments. Subjects completed the…

  17. Demographic Determinants of Locus of Control among Medical ...

    African Journals Online (AJOL)

    The Levenson Multidimensional Locus of Control Inventory and a Socio - demographic data collection sheet were used to collect data from 262 (183 males and 79 females) students selected through convenience sampling. Data were th analyzed using the 16th version of the SPPS. Percentages, means, t-test and ANOVA ...

  18. Single locus complementary sex determination in Hymenoptera : an "unintelligent" design?

    NARCIS (Netherlands)

    Wilgenburg, Ellen van; Driessen, Gerard; Beukeboom, Leo W.

    2006-01-01

    The haplodiploid sex determining mechanism in Hymenoptera (males are haploid, females are diploid) has played an important role in the evolution of this insect order. In Hymenoptera sex is usually determined by a single locus, heterozygotes are female and hemizygotes are male. Under inbreeding,

  19. Single locus complementary sex determination in Hymenoptera: an "unintelligent" design?

    NARCIS (Netherlands)

    van Wilgenburg, E.; Driessen, G.J.J.; Beukeboom, L.W.

    2006-01-01

    The haplodiploid sex determining mechanism in Hymenoptera (males are haploid, females are diploid) has played an important role in the evolution of this insect order. In Hymenoptera sex is usually determined by a single locus, heterozygotes are female and hemizygotes are male. Under inbreeding,

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

    Science.gov (United States)

    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.…

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

    Science.gov (United States)

    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…

  2. Influences of peer relations and locus of control on students ...

    African Journals Online (AJOL)

    Effort to checkmate extravagance and maximize gain is the focus of all organizations more in this period of global financial crisis. There is need therefore to checkmate unnecessary financial spending. This study examines the influence of the variables, peer relations and locus of control, on such spending among University ...

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

    Science.gov (United States)

    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…

  4. A multi-locus phylogenetic evaluation of Diaporthe (Phomopsis)

    NARCIS (Netherlands)

    Udayanga, D.; Liu, X.; Crous, P.W.; McKenzie, E.H.C.; Chukeatirote, E.; Hyde, K.D.

    2012-01-01

    The genus Diaporthe (Phomopsis) includes important plant pathogenic fungi with wide host ranges and geographic distributions. In the present study, phylogenetic species recognition in Diaporthe is re-evaluated using a multi-locus phylogeny based on a combined data matrix of rDNA ITS, and partial

  5. Relationship between internet addiction and academic locus of ...

    African Journals Online (AJOL)

    The study identified the various internet activities engaged in by students in a Nigerian University and examined the relationship between internet addiction and their academic locus of control. The sample was made of 250 students selected from a University in Nigeria. An instrument tagged “Questionnaire on Students' ...

  6. Arousal, exploration and the locus coeruleus-norepinephrine system

    NARCIS (Netherlands)

    Jepma, Marieke

    2011-01-01

    The studies described in this thesis address a range of topics related to arousal, exploration, temporal attention, and the locus coeruleus-norepinephrine (LC-NE) system. Chapters 2 and 3 report two studies that investigated a recent theory about the role of the LC-NE system in the regulation of the

  7. Locus of Control and Likelihood of Nuclear War: Two Studies.

    Science.gov (United States)

    Erdahl, Paul; Rounds, James B.

    The Nuclear Locus of Control (NLOC) scales were constructed to assess beliefs as to whether nuclear war and nuclear policy decisions are, or can be, influenced by oneself, powerful others, or chance. Three scales measuring internal, powerful others, and chance nuclear LOC show internal consistency estimates (Cronbach's Alpha) of .87, .76, and .85,…

  8. Strengthening Locus Standi in Human Rights Litigation in Zimbabwe ...

    African Journals Online (AJOL)

    MJM Venter

    2016-05-30

    May 30, 2016 ... approach is likely to impact on the right to access to justice and human rights protection. 2. Locus standi ... Committee on Economic, Social and Cultural Rights General Comment 9: The. Domestic .... animosity towards an accused, in bad faith and without any warrant, were to rule that the question raised by ...

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

    Science.gov (United States)

    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…

  10. DNA marker mining of ILSTS035 microsatellite locus on ...

    Indian Academy of Sciences (India)

    Unknown

    We describe tests for detecting and locating quantitative trait loci (QTL) for traits in Hanwoo cattle. From results of a permutation test to detect QTL for marbling, we selected the microsatellite locus ILSTS035 on chromosome 6 for further analysis. K-means clustering analysis applied to five traits and nine DNA markers in ...

  11. Determination of the yield locus by means of temperature measurement

    NARCIS (Netherlands)

    Banabic, D.; Huetink, Han

    2006-01-01

    The paper presents a theoretical background of the thermo-graphical method of determining the yield locus. The analytical expression of the temperature variation of the specimen deformed in the elastic state is determined starting from the first law of thermodynamics. The experimental method for

  12. Inferring relationships between pairs of individuals from locus heterozygosities

    Directory of Open Access Journals (Sweden)

    Spinetti Isabella

    2002-11-01

    Full Text Available Abstract 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.

  13. Response to selection in finite locus models with nonadditive effects

    NARCIS (Netherlands)

    Esfandyari, Hadi; Henryon, Mark; Berg, Peer; Thomasen, Jørn Rind; Bijma, Piter; Sørensen, Anders Christian

    2017-01-01

    Under the finite-locus model in the absence of mutation, the additive genetic variation is expected to decrease when directional selection is acting on a population, according to quantitative-genetic theory. However, some theoretical studies of selection suggest that the level of additive

  14. Locus of control and investment in risky assets

    NARCIS (Netherlands)

    Salamanca Acosta, Nicolas; de Grip, A.; Fouarge, Didier; Montizaan, Raymond

    2016-01-01

    We show that household heads with a strong internal economic locus of control are more likely to hold equity and hold a larger share of equity in their investment portfolio. This relation holds when we control for economic preferences and possible confounders such as financial literacy,

  15. 40 CFR 798.5195 - Mouse biochemical specific locus test.

    Science.gov (United States)

    2010-07-01

    ...-induced variants are bred to determine the genetic nature of the change. (f) Data and reports—(1... SUBSTANCES CONTROL ACT (CONTINUED) HEALTH EFFECTS TESTING GUIDELINES Genetic Toxicity § 798.5195 Mouse...) A biochemical specific locus mutation is a genetic change resulting from a DNA lesion causing...

  16. Emotional intelligence and locus of control of adult patients with ...

    African Journals Online (AJOL)

    Background: This article investigates emotional intelligence and locus of control in an adult breast cancer population receiving treatment. Gaining insight into these constructs will contribute to improving breast cancer patients' psychological well-being and to reducing physical vulnerability to disease before and during ...

  17. The Locus of Metaphorical Persuasion: An Empirical Test.

    Science.gov (United States)

    Hitchon, Jacqueline C.

    1997-01-01

    Investigates whether the locus of persuasion of the metaphor "A is B" lies in the valence of B, as widely assumed, or in the valence of the metaphor ground, what A and B share. Indicates that global affect toward B does not transfer onto A and that metaphorical persuasion is a distinct process meriting further investigation. (SR)

  18. Social support, locus of control, and psychological well-being

    NARCIS (Netherlands)

    van der Zee, KI; Buunk, BP; Sanderman, R

    1997-01-01

    Social support seems to be positively related to psychological well-being. Studies have shown that individual differences exist in the ability to mobilize and use sources of support. The current study focused on locus of control as a personality factor that might be related to this ability, In 2

  19. Locus of Control and Neuropsychological Performance in Chronic Alcoholics.

    Science.gov (United States)

    Shelton, M. D.; And Others

    1982-01-01

    Examined correlated neuropsychological performance in male chronic alcoholics and non-alcoholic controls. Results showed external locus of control (LOC-E) scores to predict performance on neuropsychological tests in alcoholics but not in controls. Suggests the LOC-E variables cannot account for the widespread differences between the groups on…

  20. New distal marker closely linked to the fragile X locus

    NARCIS (Netherlands)

    Hulsebos, T. J.; Oostra, B. A.; Broersen, S.; Smits, A.; van Oost, B. A.; Westerveld, A.

    1991-01-01

    We have isolated II-10, a new X-chromosomal probe that identifies a highly informative two-allele TaqI restriction fragment length polymorphism at locus DXS466. Using somatic cell hybrids containing distinct portions of the long arm of the X chromosome, we could localize DXS466 between DXS296 and

  1. DMPD: The Lps locus: genetic regulation of host responses to bacteriallipopolysaccharide. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 10669111 The Lps locus: genetic regulation of host responses to bacteriallipopolysaccharide. Qur...e The Lps locus: genetic regulation of host responses to bacteriallipopolysaccharide. Authors Qur

  2. [Relationship between work locus of control and occupational stress in oil workers].

    Science.gov (United States)

    Meng, Xian-Hai; He, Ya-Hui; Yu, Shan-Fa; Qi, Xiu-Ying

    2008-12-01

    To investigate general states of the work locus of control and explore the relationship between work locus of control and occupational stress in oil workers. 582 oil workers were investigated by using the General Questionnaire and Occupational Stress Measure Inventory. There were significant differences in WCLS score between two age groups (= 30 years old group and locus of control; values of role ambiguity, working prospect, depression and social support were higher in the group of external locus of control (P locus of control had positive relation with role ambiguity, working prospect, depression, and social support, and negative with interpersonal relationship, promotion, participation, task consistency, challenge, job satisfaction, mental health, self-esteem and coping strategies. In the regression analysis, work locus of control was the major predictive factor of work satisfaction. Work locus of control is associated with many occupational stress factors. The group of extrinsic work locus of control experience more stress in oil workers.

  3. A cut locus for finite graphs and the farthest point mapping

    DEFF Research Database (Denmark)

    Maddaloni, Alessandro; Zamfirescu, Carol T.

    2016-01-01

    We reflect upon an analogue of the cut locus, a notion classically studied in Differential Geometry, for finite graphs. The cut locus C(x) of a vertex x shall be the graph induced by the set of all vertices y with the property that no shortest path between x and z, z≠y, contains y. The cut locus ...

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    Goodman, Wendy; Leggett, Janice; Garrett, Tanya

    2007-01-01

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

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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…

  8. Characterization of a Multipeptide Lantibiotic Locus in Streptococcus pneumoniae.

    Science.gov (United States)

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

    2016-01-26

    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. Successful colonization of a polymicrobial host surface is a prerequisite for the subsequent development of disease for many bacterial pathogens. Bacterial factors that directly inhibit the growth of neighbors

  9. Refined localization of the Prieto-syndrome locus

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, F.; Prieto, F. [Unidad de Genetica, Valencia (Spain); Gal, A. [Universitaets-Krankenhaus Eppendorf, Hamburg (Germany)

    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.

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

    Science.gov (United States)

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

    2012-06-01

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

  11. Characterization of a Multipeptide Lantibiotic Locus in Streptococcus pneumoniae

    Directory of Open Access Journals (Sweden)

    Natalie Maricic

    2016-01-01

    Full Text Available 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.

  12. 'Locus of control', health-related quality of life, emotional distress and disability in Parkinson's disease.

    Science.gov (United States)

    Rizza, Federica; Gison, Annalisa; Bonassi, Stefano; Dall'Armi, Valentina; Tonto, Francesca; Giaquinto, Salvatore

    2017-06-01

    This cross-sectional study evaluated locus of control and its subscales in Parkinson's disease. A total of 50 consecutive Parkinson's disease participants and 50 healthy volunteers (control group) were enrolled. External locus of control was significantly higher in Parkinson's disease participants, whereas internal locus of control had no significant differences. External locus of control and internal locus of control were correlated in control group, but not in Parkinson's disease. In Parkinson's disease participants, external locus of control was negatively associated with health-related quality of life as well as positively associated with emotional distress and disease severity (but not with disability). After adjusting to confound variables, the associations remained. On the other hand, internal locus of control was negatively associated with depression.

  13. The Effects of Locus of Control and Task Difficulty on Procrastination.

    Science.gov (United States)

    Janssen, Tracy; Carton, John S

    1999-12-01

    The authors investigated the effects of locus of control expectancies and task difficulty on procrastination. Forty-two college students were administered an academic locus of control scale and a task that was similar to a typical college homework assignment. The students were randomly assigned to 1 of 2 task difficulty levels. Although none of the results involving task difficulty was significant, several results involving locus of control were significant. Specifically, analyses revealed that students with internal locus of control expectancies tended to begin working on the assignment sooner than students with external locus of control expectancies. In addition, students with internal locus of control completed and returned the assignment sooner than students with external locus of control. The results are discussed within the context of J. B. Rotter's (1966, 1975, 1982) social learning theory.

  14. Genetic analysis of the claret locus of Drosophila melanogaster

    International Nuclear Information System (INIS)

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

    1989-01-01

    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 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 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 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

  15. Population genetics of the HRAS1 minisatellite locus

    Energy Technology Data Exchange (ETDEWEB)

    Devlin, B.; Risch, N. (Yale Univ., New Haven, CT (United States)); Krontiris, T. (Tufts Univ., Boston, MA (United States) New England Medical Center Hospital, Boston, MA (United States))

    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.

  16. Origin of allelic diversity in antirrhinum S locus RNases.

    Science.gov (United States)

    Xue, Y; Carpenter, R; Dickinson, H G; Coen, E S

    1996-01-01

    In many plant species, self-incompatibility (SI) is genetically controlled by a single multiallelic S locus. Previous analysis of S alleles in the Solanaceae, in which S locus ribonucleases (S RNases) are responsible for stylar expression of SI, has demonstrated that allelic diversity predated speciation within this family. To understand how allelic diversity has evolved, we investigated the molecular basis of gametophytic SI in Antirrhinum, a member of the Scrophulariaceae, which is closely related to the Solanaceae. We have characterized three Antirrhinum cDNAs encoding polypeptides homologous to S RNases and shown that they are encoded by genes at the S locus. RNA in situ hybridization revealed that the Antirrhinum S RNase are primarily expressed in the stylar transmitting tissue. This expression is consistent with their proposed role in arresting the growth of self-pollen tubes. S alleles from the Scrophulariaceae form a separate group from those of the Solanaceae, indicating that new S alleles have been generated since these families separated (approximately 40 million years). We propose that the recruitment of an ancestral RNase gene into SI occurred during an early stage of angiosperm evolution and that, since that time, new alleles subsequently have arisen at a low rate. PMID:8672882

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

    Energy Technology Data Exchange (ETDEWEB)

    Zonana, J.; Jones, M.; Litt, M.; Kramer, P.; Browne, D.; Becker, H.W. (Oregon Health Sciences Univ., Portland, OR (United States)); Brockdorff, N.; Rastan, S. (Medical Council Clinical Research Centre, Harrow (United Kingdom)); Davies, K.P.; Clarke, A. (Univ. of Wales College of Medicine, Cardiff (United Kingdom)) (and others)

    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.

  18. Locus de Controle e escolha do método anticoncepcional Locus de Control y método anticonceptivo elegido Locus of Control and choice of contraceptive method

    Directory of Open Access Journals (Sweden)

    Aline Salheb Alves

    2007-06-01

    Full Text Available Objetivou-se avaliar a relação entre o Locus de Controle e o tipo de método contraceptivo escolhido. Foi utilizada a Escala Multidimensional de Locus de Controle de Levenson e entrevistadas 191 mulheres. As usuárias de preservativo masculino apresentaram maior Internalidade do que as usuárias de injetável mensal. Quanto ao locus Externalidade Outros Poderosos, as usuárias de implante apresentavam menor externalidade do que as usuárias de preservativo masculino, laqueadura, injetável trimestral e DIU. Considerando-se o locus Externalidade Acaso, as usuárias de implante apresentaram menores escores do que as mulheres que optaram pela laqueadura, injetável trimestral e DIU. Observou-se ainda, menor Externalidade Acaso entre as usuárias de injetável mensal em relação às mulheres que fizeram opção pelo injetável trimestral.El objetivo es validar la relación entre el Locus de Control y el tipo de método anticonceptivo elegido. Fue usada la Escala Multidimensional de Locus de Control de Levenson. Fueron entrevistadas 191 mujeres. Las usuarias de condón masculino presentaron Internalidad más grande que las usuarias de inyectable mensual. Considerado el Locus Externalidad - Otro poderoso, las usuarias de implante presentaron menor externalidad de que las usuarias de condón masculino, laqueadura, inyectable trimestral y DIU. Considerado el Locus Externalidad - Quizá, las usuarias del implante presentaron menores resultados que las mujeres que eligieron por la laqueadura, inyectable trimestral y DIU. Se observo que las mujeres usuarias de inyectable mensual presentaron menor Externalidad - Quizá que las mujeres usuarias de inyectable trimestral.The purpose was to assess the relationship between locus of control and the contraceptive method chosen. It was used the Levenson's Multidimensional Locus of Control Scale and 191 women was interviewed. Users of male condoms presented greater Internality than the monthly contraceptive

  19. A segment of the apospory-specific genomic region is highly microsyntenic not only between the apomicts Pennisetum squamulatum and buffelgrass, but also with a rice chromosome 11 centromeric-proximal genomic region.

    Science.gov (United States)

    Gualtieri, Gustavo; Conner, Joann A; Morishige, Daryl T; Moore, L David; Mullet, John E; Ozias-Akins, Peggy

    2006-03-01

    Bacterial artificial chromosome (BAC) clones from apomicts Pennisetum squamulatum and buffelgrass (Cenchrus ciliaris), isolated with the apospory-specific genomic region (ASGR) marker ugt197, were assembled into contigs that were extended by chromosome walking. Gene-like sequences from contigs were identified by shotgun sequencing and BLAST searches, and used to isolate orthologous rice contigs. Additional gene-like sequences in the apomicts' contigs were identified by bioinformatics using fully sequenced BACs from orthologous rice contigs as templates, as well as by interspecies, whole-contig cross-hybridizations. Hierarchical contig orthology was rapidly assessed by constructing detailed long-range contig molecular maps showing the distribution of gene-like sequences and markers, and searching for microsyntenic patterns of sequence identity and spatial distribution within and across species contigs. We found microsynteny between P. squamulatum and buffelgrass contigs. Importantly, this approach also enabled us to isolate from within the rice (Oryza sativa) genome contig Rice A, which shows the highest microsynteny and is most orthologous to the ugt197-containing C1C buffelgrass contig. Contig Rice A belongs to the rice genome database contig 77 (according to the current September 12, 2003, rice fingerprint contig build) that maps proximal to the chromosome 11 centromere, a feature that interestingly correlates with the mapping of ASGR-linked BACs proximal to the centromere or centromere-like sequences. Thus, relatedness between these two orthologous contigs is supported both by their molecular microstructure and by their centromeric-proximal location. Our discoveries promote the use of a microsynteny-based positional-cloning approach using the rice genome as a template to aid in constructing the ASGR toward the isolation of genes underlying apospory.

  20. A Segment of the Apospory-Specific Genomic Region Is Highly Microsyntenic Not Only between the Apomicts Pennisetum squamulatum and Buffelgrass, But Also with a Rice Chromosome 11 Centromeric-Proximal Genomic Region1[W

    Science.gov (United States)

    Gualtieri, Gustavo; Conner, Joann A.; Morishige, Daryl T.; Moore, L. David; Mullet, John E.; Ozias-Akins, Peggy

    2006-01-01

    Bacterial artificial chromosome (BAC) clones from apomicts Pennisetum squamulatum and buffelgrass (Cenchrus ciliaris), isolated with the apospory-specific genomic region (ASGR) marker ugt197, were assembled into contigs that were extended by chromosome walking. Gene-like sequences from contigs were identified by shotgun sequencing and BLAST searches, and used to isolate orthologous rice contigs. Additional gene-like sequences in the apomicts' contigs were identified by bioinformatics using fully sequenced BACs from orthologous rice contigs as templates, as well as by interspecies, whole-contig cross-hybridizations. Hierarchical contig orthology was rapidly assessed by constructing detailed long-range contig molecular maps showing the distribution of gene-like sequences and markers, and searching for microsyntenic patterns of sequence identity and spatial distribution within and across species contigs. We found microsynteny between P. squamulatum and buffelgrass contigs. Importantly, this approach also enabled us to isolate from within the rice (Oryza sativa) genome contig Rice A, which shows the highest microsynteny and is most orthologous to the ugt197-containing C1C buffelgrass contig. Contig Rice A belongs to the rice genome database contig 77 (according to the current September 12, 2003, rice fingerprint contig build) that maps proximal to the chromosome 11 centromere, a feature that interestingly correlates with the mapping of ASGR-linked BACs proximal to the centromere or centromere-like sequences. Thus, relatedness between these two orthologous contigs is supported both by their molecular microstructure and by their centromeric-proximal location. Our discoveries promote the use of a microsynteny-based positional-cloning approach using the rice genome as a template to aid in constructing the ASGR toward the isolation of genes underlying apospory. PMID:16415213

  1. Examining the relationship between health locus of control and God Locus of Health Control: Is God an internal or external source?

    Science.gov (United States)

    Boyd, Joni M; Wilcox, Sara

    2017-11-01

    For many people, the influence of believing in a higher power can elicit powerful effects. This study examined the relationship between God control, health locus of control, and frequency of religious attendance within 838 college students through online surveys. Regression analysis showed that chance and external locus of control and frequency of religious attendance were significant and positive predictors of God Locus of Health Control. The association of powerful others external locus of control and God Locus of Health Control differed by race (stronger in non-Whites than Whites) and somewhat by gender (stronger in women than men). For some people, the role of a supreme being, or God, should be considered when designing programs for improving health behaviors.

  2. HEALTH LOCUS OF CONTROL PERCEPTION OF ADOLESCENTS, AND ITS EFFECTS ON THEIR HEALTH BEHAVIOURS

    Directory of Open Access Journals (Sweden)

    Ruhi Selcuk TABAK

    2006-04-01

    Full Text Available Main objective of this study is to investigate the relationships between health locus of control perceptions and health behaviours of adolescents as well as the effectiveness of lectures on health locus of control to them. The subjects of our study are 192 students in 6 groups of the 9. Grade students of a high school. Three groups of 108 students were randomly selected as the experiment group who were subjected to 4 class-hours specific lectures on health locus of control. The rest 84 students constituted the control group. A 34-item questionnaire for health behaviours and the Multidimensional Health Locus of Control Scale (MHLOC, were filled by the students before and after the lectures. The lectures on health locus of control increased the perception of internal health locus of control of adolescents while decreasing chance health locus of control. The differences between experiment and control groups in this aspect were found to be statistically significant. Internal health locus of control is the main source for the increase of responsibility and management of individuals on their health. The relations that were detected between students’ health behaviours and information solicitation and their perceptions of health locus of control showed that the students with higher internal health locus of control are more eager to be responsible and active for their health, especially, for the health behaviours such as physical exercise, smoking, tooth-brushing, medical check-ups so on. [TAF Prev Med Bull 2006; 5(2.000: 118-130

  3. Factor structure, reliability, and validity of the Levenson's Locus of Control Scale in Iranian infertile people.

    Science.gov (United States)

    Maroufizadeh, Saman; Omani Samani, Reza; Amini, Payam; Navid, Behnaz

    2016-09-01

    This study examined psychometric properties of the Levenson's Locus of Control Scale among Iranian infertile patients. In all, 312 infertile patients completed the Levenson's Locus of Control Scale and Hospital Anxiety and Depression Scale. The confirmatory factor analysis indicated that the original three-factor model of Levenson's Locus of Control Scale was adequate ( χ 2 / df = 2.139; goodness-of-fit index = 0.88; root mean square error of approximation = 0.061; and standardized root mean square residual = 0.076). The Cronbach's alpha of the subscales ranged from 0.56 to 0.67. The Levenson's Locus of Control Scale subscales significantly correlated with anxiety and depression, showing an acceptable convergent validity. In conclusion, the Levenson's Locus of Control Scale has adequate reliability and validity and can be used to measure locus of control orientation in Iranian infertile patients.

  4. Locus of the apices of projectile trajectories under constant drag

    Science.gov (United States)

    Hernández-Saldaña, H.

    2017-11-01

    Using the hodograph method, we present an analytical solution for projectile coplanar motion under constant drag, parametrised by the velocity angle. We find the locus formed by the apices of the projectile trajectories, and discuss its implementation for the motion of a particle on an inclined plane in presence of Coulomb friction. The range and time of flight are obtained numerically, and we find that the optimal launching angle is smaller than in the drag-free case. This is a good example of a problem with constant dissipation of energy that includes curvature; it is appropriate for intermediate courses of mechanics.

  5. Measurement of supernatural belief: sex differences and locus of control.

    Science.gov (United States)

    Randall, T M; Desrosiers, M

    1980-10-01

    Although we live in an age dominated by science and technology, there exists an increasingly popular anti-science sentiment. This study describes the development of a scale to assess the degree of personal acceptance of supernatural causality versus acceptance of scientific explanation. In addition to the psychometric data concerning validity and reliability of the scale, data are presented which showed the personality factor of supernaturalism to be independent of orthodox religious attitudes. Results indicated a significantly greater supernatural acceptance for women, and a positive relation of supernaturalism with external locus of control.

  6. The RSF1 histone-remodelling factor facilitates DNA double-strand break repair by recruiting centromeric and Fanconi Anaemia proteins.

    Directory of Open Access Journals (Sweden)

    Fabio Pessina

    2014-05-01

    Full Text Available ATM is a central regulator of the cellular responses to DNA double-strand breaks (DSBs. Here we identify a biochemical interaction between ATM and RSF1 and we characterise the role of RSF1 in this response. The ATM-RSF1 interaction is dependent upon both DSBs and ATM kinase activity. Together with SNF2H/SMARCA5, RSF1 forms the RSF chromatin-remodelling complex. Although RSF1 is specific to the RSF complex, SNF2H/SMARCA5 is a catalytic subunit of several other chromatin-remodelling complexes. Although not required for checkpoint signalling, RSF1 is required for efficient repair of DSBs via both end-joining and homology-directed repair. Specifically, the ATM-dependent recruitment to sites of DSBs of the histone fold proteins CENPS/MHF1 and CENPX/MHF2, previously identified at centromeres, is RSF1-dependent. In turn these proteins recruit and regulate the mono-ubiquitination of the Fanconi Anaemia proteins FANCD2 and FANCI. We propose that by depositing CENPS/MHF1 and CENPX/MHF2, the RSF complex either directly or indirectly contributes to the reorganisation of chromatin around DSBs that is required for efficient DNA repair.

  7. Centromere Protein (CENP)-W Interacts with Heterogeneous Nuclear Ribonucleoprotein (hnRNP) U and May Contribute to Kinetochore-Microtubule Attachment in Mitotic Cells

    Science.gov (United States)

    Chun, Younghwa; Kim, Raehyung; Lee, Soojin

    2016-01-01

    Background Recent studies have shown that heterogeneous nuclear ribonucleoprotein U (hnRNP U), a component of the hnRNP complex, contributes to stabilize the kinetochore-microtubule interaction during mitosis. CENP-W was identified as an inner centromere component that plays crucial roles in the formation of a functional kinetochore complex. Results We report that hnRNP U interacts with CENP-W, and the interaction between hnRNP U and CENP-W mutually increased each other’s protein stability by inhibiting the proteasome-mediated degradation. Further, their co-localization was observed chiefly in the nuclear matrix region and at the microtubule-kinetochore interface during interphase and mitosis, respectively. Both microtubule-stabilizing and microtubule-destabilizing agents significantly decreased the protein stability of CENP-W. Furthermore, loss of microtubules and defects in microtubule organization were observed in CENP-W-depleted cells. Conclusion Our data imply that CENP-W plays an important role in the attachment and interaction between microtubules and kinetochore during mitosis. PMID:26881882

  8. Locus de control y conocimiento, actitud y práctica contraceptivas entre adolescentes universitarios

    OpenAIRE

    Alves, Aline Salheb; Lopes, Maria Helena Baena de Moraes

    2010-01-01

    OBJECTIVE: To assess the relationship between locus of control and knowledge, attitude and practice regarding pill and condom use among university students. METHODS: The inquiry was developed in Campinas, a city in Southeastern Brazil, in 2006. A total of 295 adolescent newcomers to a public university answered a structured questionnaire and Levenson's multidimensional locus of control scale. The scores of the dimensions of locus of control were calculated and Spearman's correlation coefficie...

  9. Locus of Control and Career Interest of Sophomore Accountancy Students: Basis for Employment Path

    OpenAIRE

    Jovielyn Mañibo; Elna Lopez

    2014-01-01

    This academic undertaking sought to determine the relationship between the locus of control and career interest of the respondents towards their future employment. The objectives of the study were to determine the respondents’ locus of control and career interest; to find if there is a significant relationship between the respondents’ locus of control and career interest and to develop an action plan that will gauge the students’ employment success as to their chosen field. In ...

  10. Characterization of additional rabbit IgM allotypes and the effect of suppression of a VH locus allotypes on the expression of n Cμ locus allotype

    International Nuclear Information System (INIS)

    Gilman-Sachs, A.; Roux, K.H.; Horing, W.J.; Dray, S.

    1982-01-01

    Anti-allotype antisera were produced that identified eight rabbit IgM allotypic specificities, n80, n81, n82, n83, n84, n85, n86, and n87. The n locus Cμ genes controlling these IgM allotypic specificities are closely linked to the a (VH subgroup) locus. The genes controlling these allotypic specificities were found to be in the heavy chain chromosomal region and were assigned to 11 haplotypes present in our rabbit colony. The n locus and a locus genes appeared in the haplotypes in six combinations: a 1 n 81 , a 2 n/sup 81,n87/, a 1 n/sup 80,83/, a 2 n/sup 80,82,87/, a 3 n/sup 81,84,85/ and a 3 n/sup 80,84,86,87/. By radioprecipitation analysis, 70 to 80% of serum IgM reacts with the antiserum directed to each n locus allotypic specificity found encoded in one haplotype; thus, each allotypic specificity of the haplotype is present on the same IgM molecule. When sera from a locus allotype-suppressed homozygous rabbits were tested for expression of each n locus allotypic specificity, n80, n81, and n87 were still expressed, whereas n82, n83, n84, n85, and n86 were not. These data provide direct evidence that some IgM specificities are expressed independently of the a locus (i.e., ''true''), and other s are dependent on the expression of an a locus specificity (i.e., conformational). The expression of the ''true'' allotypic specificities probably reflects genetic control of the germline Cμ gene, and the expression of ''conformationally dependent'' allotypic specificities probably reflects the interaction of VH and Cμ gene segments. This distinction is important and must be recognized when evaluating the genetics and structure of the IgM molecule

  11. External locus of control contributes to racial disparities in memory and reasoning training gains in ACTIVE

    Science.gov (United States)

    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

  12. External locus of control contributes to racial disparities in memory and reasoning training gains in ACTIVE.

    Science.gov (United States)

    Zahodne, Laura B; Meyer, Oanh L; Choi, Eunhee; Thomas, Michael L; Willis, Sherry L; Marsiske, Michael; Gross, Alden L; Rebok, George W; Parisi, Jeanine M

    2015-09-01

    Racial disparities in cognitive outcomes may be partly explained by differences in locus of control. African Americans report more external locus of control than non-Hispanic Whites, and external locus of control is associated with poorer health and cognition. The aims of this study were to compare cognitive training gains between African American and non-Hispanic White participants in the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study and determine whether racial differences in training gains are mediated by locus of control. The sample comprised 2,062 (26% African American) adults aged 65 and older who participated in memory, reasoning, or speed training. Latent growth curve models evaluated predictors of 10-year cognitive trajectories separately by training group. Multiple group modeling examined associations between training gains and locus of control across racial groups. Compared to non-Hispanic Whites, African Americans evidenced less improvement in memory and reasoning performance after training. These effects were partially mediated by locus of control, controlling for age, sex, education, health, depression, testing site, and initial cognitive ability. African Americans reported more external locus of control, which was associated with smaller training gains. External locus of control also had a stronger negative association with reasoning training gain for African Americans than for Whites. No racial difference in training gain was identified for speed training. Future intervention research with African Americans should test whether explicitly targeting external locus of control leads to greater cognitive improvement following cognitive training. (c) 2015 APA, all rights reserved).

  13. Role of Oculoproprioception in Coding the Locus of Attention.

    Science.gov (United States)

    Odoj, Bartholomaeus; Balslev, Daniela

    2016-03-01

    The most common neural representations for spatial attention encode locations retinotopically, relative to center of gaze. To keep track of visual objects across saccades or to orient toward sounds, retinotopic representations must be combined with information about the rotation of one's own eyes in the orbits. Although gaze input is critical for a correct allocation of attention, the source of this input has so far remained unidentified. Two main signals are available: corollary discharge (copy of oculomotor command) and oculoproprioception (feedback from extraocular muscles). Here we asked whether the oculoproprioceptive signal relayed from the somatosensory cortex contributes to coding the locus of attention. We used continuous theta burst stimulation (cTBS) over a human oculoproprioceptive area in the postcentral gyrus (S1EYE). S1EYE-cTBS reduces proprioceptive processing, causing ∼1° underestimation of gaze angle. Participants discriminated visual targets whose location was cued in a nonvisual modality. Throughout the visual space, S1EYE-cTBS shifted the locus of attention away from the cue by ∼1°, in the same direction and by the same magnitude as the oculoproprioceptive bias. This systematic shift cannot be attributed to visual mislocalization. Accuracy of open-loop pointing to the same visual targets, a function thought to rely mainly on the corollary discharge, was unchanged. We argue that oculoproprioception is selective for attention maps. By identifying a potential substrate for the coupling between eye and attention, this study contributes to the theoretical models for spatial attention.

  14. Single locus complementary sex determination in Hymenoptera: an "unintelligent" design?

    Directory of Open Access Journals (Sweden)

    Driessen Gerard

    2006-01-01

    Full Text Available Abstract The haplodiploid sex determining mechanism in Hymenoptera (males are haploid, females are diploid has played an important role in the evolution of this insect order. In Hymenoptera sex is usually determined by a single locus, heterozygotes are female and hemizygotes are male. Under inbreeding, homozygous diploid and sterile males occur which form a genetic burden for a population. We review life history and genetical traits that may overcome the disadvantages of single locus complementary sex determination (sl-CSD. Behavioural adaptations to avoid matings between relatives include active dispersal from natal patches and mating preferences for non-relatives. In non-social species, temporal and spatial segregation of male and female offspring reduces the burden of sl-CSD. In social species, diploid males are produced at the expense of workers and female reproductives. In some social species, diploid males and diploid male producing queens are killed by workers. Diploid male production may have played a role in the evolution or maintenance of polygyny (multiple queens and polyandry (multiple mating. Some forms of thelytoky (parthenogenetic female production increase homozygosity and are therefore incompatible with sl-CSD. We discuss a number of hypothetical adaptations to sl-CSD which should be considered in future studies of this insect order.

  15. [Locus of control in girls with anorexia readiness syndrome].

    Science.gov (United States)

    Jaros, Katarzyna; Oszwa, Urszula

    2014-01-01

    The aim of the research was to indicate whether there are differences between locus of control (LOC) in girls with anorexia readiness syndrome (ARS) and without this syndrome. There was also a question about the relationship between LOC and the tendency to respond in incorrect attitudes towards food, eating and their bodies under stress. The sample consisted of girls aged 13-18 years randomly selected from five public Polish middle and high schools. Tools: 1) Eating Attitudes Questionnaire (EAQ) by B. Ziółkowska; 2) Locus of Control Questionnaire (LOCQ) by G. Krasowicz, A. Kurzyp-Wojnarska, to assess LOC of the subjects. The criterion group (N=23) was formed by girls who received high score in EAQ (signs of ARS) in the first stage of research (N=189). The control group (N = 23) were girls who received a low score in EAQ (no signs of ARS). Subjects with ARS were characterized by more external LOC than girls without any signs of this syndrome (t = -2.898; p control, LOC may play a role as a mediating variable rather than a direct determinant of this syndrome.

  16. Allelism of Genes in the Ml-a locus

    DEFF Research Database (Denmark)

    Giese, Nanna Henriette; Jensen, Hans Peter; Jørgensen, Jørgen Helms

    1980-01-01

    Seven barley lines or varieties, each with a different gene at the Ml-a locus for resistance to Erysiphe graminis were intercrossed. Progeny testing of the F2s using two different fungal isolates per cross provided evidence that there are two or more loci in the Ml-a region. Apparent recombinants...... were also screened for recombination between the Hor1 and Hor2 loci which are situated either side of the Ml-a locus. The cross between Ricardo and Iso42R (Rupee) yielded one possible recombinant, with Ml-a3 and Ml-a(Rul) in the coupling phase; other recombinants had wild-type genes in the coupling...... phase. Iso20R, derived from Hordeum spontaneum 'H204', carrying Ml-a6, had an additional gene, in close coupling with Ml-a6, tentatively named Ml-aSp2 or Reglv, causing an intermediate infection type with isolate EmA30. It is suggested that Ml-a(Ar) in Emir and Ml-a(Rul), shown to differ from other Ml...

  17. Breaking bad news: patients' preferences and health locus of control.

    Science.gov (United States)

    Martins, Raquel Gomes; Carvalho, Irene Palmares

    2013-07-01

    To identify patients' preferences for models of communicating bad news and to explore how such preferences, and the reasons for the preferences, relate with personality characteristics, specifically patients' health locus of control (HLC): internal/external and 'powerful others' (PO). Seventy-two patients from an oncology clinic watched videotaped scenarios of a breaking bad news moment, selected the model they preferred, filled an HLC scale and were interviewed about their choices. Data were analyzed with Chi-square, Kruskal-Wallis and Mann-Whitney tests. Interviews were content-analyzed. 77.8% preferred an "empathic professional", 12.5% a "distanced expert" and 9.7% an "emotionally burdened expert". Preferences varied significantly with HLC scores (patients with higher internal locus of control (ILC) and lower PO preferred the empathic model), presence of cancer, age and education. Patients explained their preferences through aspects of Caring, Professionalism, Wording, Time and Hope. ILC registered significant differences in regards to Wording and Time, whereas PO was associated with Hope and Time. HLC is an important dimension that can help doctors to better know their patients. Knowing whether patients attribute their health to their own behaviors or to chance/others can help tailor the disclosure of bad news to their specific preferences. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

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

    Science.gov (United States)

    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.

  19. Are there gender differences in locus of control specific to alcohol dependence?

    Science.gov (United States)

    McPherson, Andrew; Martin, Colin R

    2017-01-01

    To investigate gender differences in locus of control in an alcohol-dependent population. Locus of control helps to explain behaviour in terms of internal (the individual is responsible) or external (outside forces, such as significant other people or chance, are responsible) elements. Past research on gender differences in locus of control in relation to alcohol dependence has shown mixed results. There is a need then to examine gender and locus of control in relation to alcohol dependence to ascertain the veracity of any locus of control differences as a function of gender. The Multidimensional Health Locus of Control form-C was administered to clients from alcohol dependence treatment centres in the West of Scotland. Independent t-tests were carried out to assess gender differences in alcohol dependence severity and internal/external aspects of locus of control. One hundred and eighty-eight (53% females) participants were recruited from a variety of alcohol dependence treatment centres. The majority of participants (72%) came from Alcoholics Anonymous groups. Women revealed a greater internal locus of control compared with men. Women also had a greater 'significant others' locus of control score than men. Men were more reliant on 'chance' and 'doctors' than women. All these trends were not, however, statistically significant. Gender differences in relation to locus of control and alcohol dependence from past studies are ambiguous. This study also found no clear statistically significant differences in locus of control orientation as a function of gender. This article helps nurses to contextualise health behaviours as a result of internal or external forces. It also helps nursing staff to better understand alcohol dependence treatment in relation to self-efficacy and control. Moreover, it highlights an important concept in health education theory. © 2016 John Wiley & Sons Ltd.

  20. Locus of control and pain: Validity of the Form C of the Multidimensional Health Locus of Control scales when used with adolescents.

    Science.gov (United States)

    Castarlenas, Elena; Solé, Ester; Racine, Mélanie; Sánchez-Rodríguez, Elisabet; Jensen, Mark P; Miró, Jordi

    2016-09-01

    The objective of this study was to examine the factor structure, reliability, and validity of the Form C of the Multidimensional Health Locus of Control scales in adolescents. A confirmatory factor analysis indicated that adequate fit of a four-factor model and the internal consistency of the scales were adequate. Criterion validity of the four scales of the Form C of the Multidimensional Health Locus of Control was also supported by significant correlations with measures of pain-related self-efficacy, anxiety, and coping strategies. The results indicate that the four Form C of the Multidimensional Health Locus of Control scale scores are reliable and valid and therefore support their use to assess pain-related locus of control beliefs in adolescents.

  1. The fester locus in Botryllus schlosseri experiences selection

    Directory of Open Access Journals (Sweden)

    Nydam Marie L

    2012-12-01

    Full Text Available Abstract 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 95% posterior probability of ω values > 1. Conclusion Fester proteins are evolving non-neutrally. The polymorphism statistics are consistent with either

  2. Locus of Control and Self-Esteem in Indian and White Students.

    Science.gov (United States)

    Martin, James C.

    1976-01-01

    The development and relationship of two dimensions of personality, self esteem and locus of control, were examined in a study of 763 fourth, eighth, and twelfth grade Indian and white children selected from 22 Oklahoma public schools. The students were given the Coopersmith Self-Esteem Inventory and Nowicky-Strickland Locus of Control Scale during…

  3. Self Esteem, Locus of Control and Multidimensional Perfectionism as the Predictors of Subjective Well Being

    Science.gov (United States)

    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…

  4. PHIP - a novel candidate breast cancer susceptibility locus on 6q14.1

    NARCIS (Netherlands)

    Jiao, X. (Xiang); Aravidis, C. (Christos); Marikkannu, R. (Rajeshwari); Rantala, J. (Johanna); Picelli, S. (Simone); Adamovic, T. (Tatjana); Liu, T. (Tao); Maguire, P. (Paula); B. Kremeyer (Barbara); Luo, L. (Liping); von Holst, S. (Susanna); Kontham, V. (Vinaykumar); Thutkawkorapin, J. (Jessada); Margolin, S. (Sara); Du, Q. (Quan); Lundin, J. (Johanna); Michailidou, K. (Kyriaki); Bolla, M.K. (Manjeet K.); Wang, Q. (Qin); Dennis, J. (Joe); Lush, M. (Michael); C.B. Ambrosone (Christine); I.L. Andrulis (Irene); H. Anton-Culver (Hoda); Antonenkova, N.N. (Natalia N.); Arndt, V. (Volker); M.W. Beckmann (Matthias); C. Blomqvist (Carl); W.J. Blot (William); Boeckx, B. (Bram); S.E. Bojesen (Stig); B. Bonnani (Bernardo); J.S. Brand (Judith S.); H. Brauch (Hiltrud); H. Brenner (Hermann); A. Broeks (Annegien); T. Brüning (Thomas); B. Burwinkel (Barbara); Cai, Q. (Qiuyin); J. Chang-Claude (Jenny); NBCS Collaborators, (); Couch, F.J. (Fergus J.); A. Cox (Angela); S.S. Cross (Simon); S.L. Deming-Halverson (Sandra); P. Devilee (Peter); I. dos Santos Silva (Isabel); Dörk, T. (Thilo); M. Eriksson (Mats); P.A. Fasching (Peter); J.D. Figueroa (Jonine); D. Flesch-Janys (Dieter); H. Flyger (Henrik); M. Gabrielson (Marike); M. García-Closas (Montserrat); Giles, G.G. (Graham G.); A. González-Neira (Anna); P. Guénel (Pascal); Q. Guo (Qi); Gündert, M. (Melanie); C.A. Haiman (Christopher); Hallberg, E. (Emily); U. Hamann (Ute); P. harrington (Patricia); M.J. Hooning (Maartje); J.L. Hopper (John); Huang, G. (Guanmengqian); A. Jakubowska (Anna); M. Jones (Michael); M. Kerin (Michael); V-M. Kosma (Veli-Matti); Kristensen, V.N. (Vessela N.); Lambrechts, D. (Diether); L. Le Marchand (Loic); J. Lubinski (Jan); A. Mannermaa (Arto); J.W.M. Martens (John); A. Meindl (Alfons); R.L. Milne (Roger); A.-M. Mulligan (Anna-Marie); S.L. Neuhausen (Susan); H. Nevanlinna (Heli); J. Peto (Julian); K. Pykäs (Katri); P. Radice (Paolo); V. Rhenius (Valerie); E.J. Sawyer (Elinor); M.K. Schmidt (Marjanka); R.K. Schmutzler (Rita); C.M. Seynaeve (Caroline); Shah, M. (Mitul); J. Simard (Jacques); Southey, M.C. (Melissa C.); A.J. Swerdlow (Anthony ); T. Truong (Thérèse); Wendt, C. (Camilla); R. Winqvist (Robert); W. Zheng (Wei); kConFab/AOCS Investigators, (); J. Benítez (Javier); A.M. Dunning (Alison); P.D.P. Pharoah (Paul); D.F. Easton (Douglas); K. Czene (Kamila); P. Hall (Per); A. Lindblom (Annika)

    2017-01-01

    textabstractMost non-BRCA1/2 breast cancer families have no identified genetic cause. We used linkage and haplotype analyses in familial and sporadic breast cancer cases to identify a susceptibility locus on chromosome 6q. Two independent genome-wide linkage analysis studies suggested a 3 Mb locus

  5. Hubungan antara Locus Of Control dan Efektivitas Komunikasi antar Pribadi dengan Problem Focused Coping

    Directory of Open Access Journals (Sweden)

    Eko Sujadi

    2016-03-01

    Full Text Available Problem focused coping need to be possessed by every individual. The purposes of this research were to described locus of control, the effectiveness of interpersonal communication, problem focused coping,the correlation between locus of control with problem focused coping, andthe correlationbetween the effectiveness of interpersonal communication with problem focused coping.This research was descriptive & correlation research by using quantitative approach. Data were collected through a Likert scale questionaire and locus of controlby using inventory Rotters Internal-External Locus of Control (I-E Scale, which was the validity and reliability has been tested. The data were analyzed by percentage technique and product moment correlation. The finding of research are:  1locus of control were in the middle range between internal locus of control and external locus of control with an average as big as 11.46, 2 the general level of effectiveness of interpersonal communication is in high category, 3 the general level of problem focused coping is in high category, 4 there is correlation between locus of control withproblem focused coping, and 5 there is correlation betweeneffectiveness of interpersonal communicationwithproblem focused coping.

  6. Predictors of Parental Locus of Control in Mothers of Pre- and Early Adolescents

    Science.gov (United States)

    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…

  7. Health Locus of Control and Preventive Behaviour among Students of Music

    Science.gov (United States)

    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,…

  8. Relationship of Personality and Locus of Control With Employment Outcomes among Participants with Spinal Cord Injury

    Science.gov (United States)

    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…

  9. The Relationship between the Perception of Own Locus of Control and Aggression of Adolescent Boys

    Science.gov (United States)

    Breet, Lettie; Myburgh, Chris; Poggenpoel, Marie

    2010-01-01

    Aggression is increasingly seen in most parts of South African society. Aggressive behaviour of boys in secondary school often results from frustrations caused by perceived high expectations of others regarding the role, locus of control, and personality of boys. Locus of control plays an important role in a person's perception concerning a…

  10. An Examination of Locus of Control, Epistemological Beliefs and Metacognitive Awareness in Preservice Early Childhood Teachers

    Science.gov (United States)

    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…

  11. Locus of Control as It Relates to the Teaching Style of Elementary Teachers

    Science.gov (United States)

    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…

  12. Goal Orientations, Locus of Control and Academic Achievement in Prospective Teachers: An Individual Differences Perspective

    Science.gov (United States)

    Bulus, Mustafa

    2011-01-01

    The aim of this study is to investigate the role of the prospective teachers' locus of control in goal orientations and of both orientations in academic achievement. The participants were 270 undergraduate students studying in different majors at the Faculty of Education in Pamukkale University. Goal Orientations and Locus of Control Scales were…

  13. The genetic and regulatory architecture of ERBB3-type 1 diabetes susceptibility locus

    DEFF Research Database (Denmark)

    Kaur, Simranjeet; Mirza, Aashiq H.; Brorsson, Caroline Anna

    2016-01-01

    -producing INS-1E cells and the genetic and regulatory architecture of the ERBB3 locus to provide insights to how rs2292239 may confer disease susceptibility. rs2292239 strongly correlated with residual β-cell function and metabolic control in children with T1D. ERBB3 locus associated lncRNA (NONHSAG011351...

  14. Social Self-Efficacy, Academic Locus of Control, and Internet Addiction

    Science.gov (United States)

    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…

  15. Authoritarian Child Rearing, Parental Locus of Control, and the Child's Behavior Style.

    Science.gov (United States)

    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…

  16. A Study to Investigate the Relationship between Locus of Control and Academic Achievement of Students

    Science.gov (United States)

    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…

  17. A Locus of Control-based HIV and AIDS Risk Reduction Training ...

    African Journals Online (AJOL)

    The aim of this study was to investigate the effi cacy of a locus of control-based training programme in reducing HIV and AIDS risk among university students. The locus of control-based variables that formed the training programme were social systems control, deferment of gratifi cation, personal values and expectancies, ...

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

    Science.gov (United States)

    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.

  19. Locus of Semantic Interference in Picture Naming: Evidence from Dual-Task Performance

    Science.gov (United States)

    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…

  20. The Effect of Locus of Control on Message Acceptance and Recall.

    Science.gov (United States)

    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…

  1. The Role of Locus of Control and Feedback on Performance of ...

    African Journals Online (AJOL)

    This study examined Students' Locus of Control and Teacher Feedback using a 2x3 factorial to measure the performance of thirty-six (36) primary school students utilizing the two locus of control types and three levels of teacher feedback: no feedback, attributional feedback, and progressive feedback. No significant ...

  2. The relationship between the perception of own locus of control and ...

    African Journals Online (AJOL)

    Aggression is increasingly seen in most parts of South African society. Aggressive behaviour of boys in secondary school often results from frustrations caused by perceived high expectations of others regarding the role, locus of control, and personality of boys. Locus of control plays an important role in a person's ...

  3. Fine-Scale Mapping of the FGFR2 Breast Cancer Risk Locus

    DEFF Research Database (Denmark)

    Meyer, Kerstin B; O'Reilly, Martin; Michailidou, Kyriaki

    2013-01-01

    The 10q26 locus in the second intron of FGFR2 is the locus most strongly associated with estrogen-receptor-positive breast cancer in genome-wide association studies. We conducted fine-scale mapping in case-control studies genotyped with a custom chip (iCOGS), comprising 41 studies (n = 89,050) of...

  4. Locus of Control, Perceptions and Attributions of Student Teachers in Educational Situations.

    Science.gov (United States)

    Kremer, Lya; Kurtz, Chaya

    Student teachers' perceptions of locus of control was investigated. Locus of control is defined as representing the extent of dependence upon inner or outer forces, the extent one is willing to invest in shaping the environment, and the perception of reinforcement as dependent upon those efforts, or upon random events. The specific questions were:…

  5. Measurement of locus copy number by hybridisation with amplifiable probes

    Science.gov (United States)

    Armour, John A. L.; Sismani, Carolina; Patsalis, Philippos C.; Cross, Gareth

    2000-01-01

    Despite its fundamental importance in genome analysis, it is only recently that systematic approaches have been developed to assess copy number at specific genetic loci, or to examine genomic DNA for submicroscopic deletions of unknown location. In this report we show that short probes can be recovered and amplified quantitatively following hybridisation to genomic DNA. This simple observation forms the basis of a new approach to determining locus copy number in complex genomes. The power and specificity of multiplex amplifiable probe hybridisation is demonstrated by the simultaneous assessment of copy number at a set of 40 human loci, including detection of deletions causing Duchenne muscular dystrophy and Prader–Willi/Angelman syndromes. Assembly of other probe sets will allow novel, technically simple approaches to a wide variety of genetic analyses, including the potential for extension to high resolution genome-wide screens for deletions and amplifications. PMID:10606661

  6. Orexin modulates behavioral fear expression through the locus coeruleus.

    Science.gov (United States)

    Soya, Shingo; Takahashi, Tohru M; McHugh, Thomas J; Maejima, Takashi; Herlitze, Stefan; Abe, Manabu; Sakimura, Kenji; Sakurai, Takeshi

    2017-11-20

    Emotionally salient information activates orexin neurons in the lateral hypothalamus, leading to increase in sympathetic outflow and vigilance level. How this circuit alters animals' behavior remains unknown. Here we report that noradrenergic neurons in the locus coeruleus (NA LC neurons) projecting to the lateral amygdala (LA) receive synaptic input from orexin neurons. Pharmacogenetic/optogenetic silencing of this circuit as well as acute blockade of the orexin receptor-1 (OX1R) decreases conditioned fear responses. In contrast, optogenetic stimulation of this circuit potentiates freezing behavior against a similar but distinct context or cue. Increase of orexinergic tone by fasting also potentiates freezing behavior and LA activity, which are blocked by pharmacological blockade of OX1R in the LC. These findings demonstrate the circuit involving orexin, NA LC and LA neurons mediates fear-related behavior and suggests inappropriate excitation of this pathway may cause fear generalization sometimes seen in psychiatric disorders, such as PTSD.

  7. Measurement of locus copy number by hybridisation with amplifiable probes.

    Science.gov (United States)

    Armour, J A; Sismani, C; Patsalis, P C; Cross, G

    2000-01-15

    Despite its fundamental importance in genome analysis, it is only recently that systematic approaches have been developed to assess copy number at specific genetic loci, or to examine genomic DNA for submicro-scopic deletions of unknown location. In this report we show that short probes can be recovered and amplified quantitatively following hybridisation to genomic DNA. This simple observation forms the basis of a new approach to determining locus copy number in complex genomes. The power and specificity of multiplex amplifiable probe hybridisation is demonstrated by the simultaneous assessment of copy number at a set of 40 human loci, including detection of deletions causing Duchenne muscular dystrophy and Prader-Willi/Angelman syndromes. Assembly of other probe sets will allow novel, technically simple approaches to a wide variety of genetic analyses, including the potential for extension to high resolution genome-wide screens for deletions and amplifications.

  8. Interrelationships of locus of control content dimensions and hopelessness.

    Science.gov (United States)

    Ward, L C; Thomas, L L

    1985-07-01

    Items from three locus of control (LOC) tests and the Beck Hopelessness Scale were administered to 197 college students. Factor analyses produced multiple factors for each LOC test, but the Beck scale proved to be unidimensional. Factor scales were constructed for each test, and scores were factor analyzed to discover common content. Each LOC test contained a salient dimension that described belief in luck, chance, or fate, and corresponding scales were well correlated. Internal control was the second common theme, with variations according to whether control was attributed to oneself or to people in general. The third common component expressed a personal helplessness or powerlessness. Each common factor was loaded by the Hopelessness Scale, which also correlated with all but one LOC factor scale.

  9. Dynamic Quantitative Trait Locus Analysis of Plant Phenomic Data.

    Science.gov (United States)

    Li, Zitong; Sillanpää, Mikko J

    2015-12-01

    Advanced platforms have recently become available for automatic and systematic quantification of plant growth and development. These new techniques can efficiently produce multiple measurements of phenotypes over time, and introduce time as an extra dimension to quantitative trait locus (QTL) studies. Functional mapping utilizes a class of statistical models for identifying QTLs associated with the growth characteristics of interest. A major benefit of functional mapping is that it integrates information over multiple timepoints, and therefore could increase the statistical power for QTL detection. We review the current development of computationally efficient functional mapping methods which provide invaluable tools for analyzing large-scale timecourse data that are readily available in our post-genome era. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. A strabismus susceptibility locus on chromosome 7p

    Science.gov (United States)

    Parikh, Vaishali; Shugart, Yin Yao; Doheny, Kimberly F.; Zhang, Jie; Li, Lan; Williams, John; Hayden, David; Craig, Brian; Capo, Hilda; Chamblee, Denise; Chen, Cathy; Collins, Mary; Dankner, Stuart; Fiergang, Dean; Guyton, David; Hunter, David; Hutcheon, Marcia; Keys, Marshall; Morrison, Nancy; Munoz, Michelle; Parks, Marshall; Plotsky, David; Protzko, Eugene; Repka, Michael X.; Sarubbi, Maria; Schnall, Bruce; Siatkowski, R. Michael; Traboulsi, Elias; Waeltermann, Joanne; Nathans, Jeremy

    2003-01-01

    Strabismus has been known to have a significant genetic component, but the mode of inheritance and the identity of the relevant genes have been enigmatic. This paper reports linkage analysis of nonsyndromic strabismus. The principal results of this study are: (i) the demonstrated feasibility of identifying and recruiting large families in which multiple members have (or had) strabismus; (ii) the linkage in one large family of a presumptive strabismus susceptibility locus to 7p22.1 with a multipoint logarithm of odds score of 4.51 under a model of recessive inheritance; and (iii) the failure to observe significant linkage to 7p in six other multiplex families, consistent with genetic heterogeneity among families. These findings suggest that it will be possible to localize and ultimately identify strabismus susceptibility genes by linkage analysis and mutation screening of candidate genes. PMID:14519848

  11. Hearing the zero locus of a magnetic field

    International Nuclear Information System (INIS)

    Montgomery, R.

    1995-01-01

    We investigate the ground state of a two-dimensional quantum particle in a magnetic field where the field vanishes nondegenerately along a closed curve. We show that the ground state concentrates on this curve as e/h tends to infinity, where e is the charge, and that the ground state energy grows like (e/h) 2/3 . These statements are true for any energy level, the level being fixed as the charge tends to infinity. If the magnitude of the gradient of the magnetic field is a constant b 0 along its zero locus, then we get the precise asymptotics (e/h) 2/3 (b 0 ) 2/3 E * + O(1) for every energy level. The constant E * ≅ .5698 is the infimum of the ground state energies E(β) of the anharmonic oscillator family -d 2 /dy 2 + (1/2 y 2 - β) 2 . (orig.)

  12. A novel stroke locus identified in a northern Sweden pedigree

    DEFF Research Database (Denmark)

    Janunger, T.; Nilsson-Ardnor, S.; Wiklund, P.-G.

    2009-01-01

    OBJECTIVES: The population of northern Sweden is characterized by reduced genetic diversity and a high incidence of stroke. We sought to reduce genetic variation further, using genealogic analysis in a set of nuclear families affected by stroke, and we subsequently performed a genome-wide scan...... to identify novel stroke susceptibility loci. METHODS: Through genealogy, 7 nuclear families with a common ancestor, connected over 8 generations, were identified. A genome-wide scan using 449 microsatellite markers was performed with subsequent haplotype analyses. RESULTS: A maximum allele-sharing lod score...... of 4.81 on chromosome 9q31-q33 was detected. Haplotype analysis identified a common 2.2-megabase interval in the chromosomal region in 4 of the nuclear families, where an overrepresentation of intracerebral hemorrhage was observed. CONCLUSIONS: We have identified a novel susceptibility locus for stroke...

  13. Examining the locus of age effects on complex span tasks.

    Science.gov (United States)

    McCabe, Jennifer; Hartman, Marilyn

    2003-09-01

    To investigate the locus of age effects on complex span tasks, the authors evaluated the contributions of working memory functions and processing speed. Age differences were found in measures of storage capacity, language processing speed, and lower level speed. Statistically controlling for each of these in hierarchical regressions substantially reduced, but did not eliminate, the complex span age effect. Accounting for lower level speed and storage, however, removed essentially the entire age effect, suggesting that both functions play important and independent roles. Additional evidence for the role of storage capacity was the absence of complex span age differences with span size calibrated to individual word span performance. Explanations for age differences based on inhibition and concurrent task performamce were not supported.

  14. Antibodies to SS-A/Ro-52kD and centromere in autoimmune liver disease: a clue to diagnosis and prognosis of primary biliary cirrhosis.

    Science.gov (United States)

    Granito, A; Muratori, P; Muratori, L; Pappas, G; Cassani, F; Worthington, J; Ferri, S; Quarneti, C; Cipriano, V; de Molo, C; Lenzi, M; Chapman, R W; Bianchi, F B

    2007-09-15

    Primary biliary cirrhosis (PBC) may be associated with various rheumatological disorders. To investigate the frequency and significance of 'rheumatological' antinuclear antibodies in the field of autoimmune chronic liver disease, with special regard to PBC. We studied 105 patients with PBC, 162 autoimmune liver disease controls (type 1 and 2 autoimmune hepatitis, primary sclerosing cholangitis), 30 systemic lupus erythematosus and 50 blood donors. Sera were tested for the presence of antibodies to extractable nuclear antigens (anti-ENA) by counterimmunoelectrophoresis, enzyme-linked and immunoblot (IB) assay, and for the presence of anti-centromere antibodies (ACA) by indirect immunofluorescence on HEp-2 cells and IB. The overall prevalence of IB-detected anti-ENA in PBC (30%) was higher than in type 1 autoimmune hepatitis (2.5%, P < 0.0001), type 2 autoimmune hepatitis (0%, P < 0.0001) and primary sclerosing cholangitis (11.5%, P = 0.006) and lower than in systemic lupus erythematosus (53%, P = 0.03). The most frequent anti-ENA reactivity in PBC was anti-SSA/Ro-52kD (28%). ACA were detected by IB in 21% PBC patients and never in the other subjects (P < 0.0001). Anti-SS-A/Ro/52kD positive PBC patients had at the time of diagnosis a more advanced histological stage (P = 0.01) and higher serum levels of bilirubin (P = 0.01) and IgM (P = 0.03) compared with negative ones. In the autoimmune liver disease setting, anti-SS-A/Ro-52kD and ACA have a high specificity for PBC and can thus be of diagnostic relevance in anti-mitochondrial antibodies negative cases. If confirmed in further studies with adequate follow-up, anti-SS-A/Ro-52kD antibodies might identify PBC patients with a more advanced and active disease.

  15. Chemogenetic locus coeruleus activation restores reversal learning in a rat model of Alzheimer's disease.

    Science.gov (United States)

    Rorabaugh, Jacki M; Chalermpalanupap, Termpanit; Botz-Zapp, Christian A; Fu, Vanessa M; Lembeck, Natalie A; Cohen, Robert M; Weinshenker, David

    2017-11-01

    See Grinberg and Heinsen (doi:10.1093/brain/awx261) for a scientific commentary on this article. Clinical evidence suggests that aberrant tau accumulation in the locus coeruleus and noradrenergic dysfunction may be a critical early step in Alzheimer’s disease progression. Yet, an accurate preclinical model of these phenotypes that includes early pretangle tau accrual in the locus coeruleus, loss of locus coeruleus innervation and deficits locus coeruleus/norepinephrine modulated behaviours, does not exist, hampering the identification of underlying mechanisms and the development of locus coeruleus-based therapies. Here, a transgenic rat (TgF344-AD) expressing disease-causing mutant amyloid precursor protein (APPsw) and presenilin-1 (PS1ΔE9) was characterized for histological and behavioural signs of locus coeruleus dysfunction reminiscent of mild cognitive impairment/early Alzheimer’s disease. In TgF344-AD rats, hyperphosphorylated tau was detected in the locus coeruleus prior to accrual in the medial entorhinal cortex or hippocampus, and tau pathology in the locus coeruleus was negatively correlated with noradrenergic innervation in the medial entorhinal cortex. Likewise, TgF344-AD rats displayed progressive loss of hippocampal norepinephrine levels and locus coeruleus fibres in the medial entorhinal cortex and dentate gyrus, with no frank noradrenergic cell body loss. Cultured mouse locus coeruleus neurons expressing hyperphosphorylation-prone mutant human tau had shorter neurites than control neurons, but similar cell viability, suggesting a causal link between pretangle tau accrual and altered locus coeruleus fibre morphology. TgF344-AD rats had impaired reversal learning in the Morris water maze compared to their wild-type littermates, which was rescued by chemogenetic locus coeruleus activation via designer receptors exclusively activated by designer drugs (DREADDs). Our results indicate that TgF344-AD rats uniquely meet several key criteria for a

  16. Association between the ABO locus and hematological traits in Korean

    Directory of Open Access Journals (Sweden)

    Hong Kyung-Won

    2012-09-01

    Full Text Available Abstract Background Recently, genome-wide association studies identified a pleiotropic gene locus, ABO, as being significantly associated with hematological traits. To confirm the effects of ABO on hematological traits, we examined the link between the ABO locus and hematological traits in Korean population-based cohorts. Results Six tagging SNPs for ABO were analyzed with regard to their effects on hematological traits [white blood cell count (WBC, red blood cell count (RBC, platelet (Plat, mean corpuscular volume (MCV, and mean corpuscular haemoglobin concentration (MCHC]. Linear regression analyses were performed, controlling for recruitment center, sex, and age as covariates. Of the 6 tagging SNPs, 3 (rs2073823, rs8176720, and rs495828 and 3 (rs2073823, rs8176717, and rs687289 were significantly associated with RBC and MCV, respectively (Bonferroni correction p-value criteria r2s = 0.99. Of the remaining 3 SNPs (rs8176720, rs8176717 and rs687289, rs8176717 generated an independent signal with moderate p-value (= 0.045 when it was adjusted for by rs2073823 (the most significant SNP. We also identified a copy number variation (CNV that was tagged by the SNP rs8176717, the minor allele of which correlated with the deletion allele of CNV. Our haplotype analysis indicated that the haplotype that contained the CNV deletion was significantly associated with MCV (β ± se = 0.363 ± 0.118, p =2.09 × 10-3. Conclusions Our findings confirm that ABO is one of the genetic factors that are associated with hematological traits in the Korean population. This result is notable, because GWASs fail to evaluate the link between a CNV and phenotype traits.

  17. The locus of semantic interference in picture naming

    Directory of Open Access Journals (Sweden)

    Pedro Macizo

    2003-01-01

    Full Text Available El locus del efecto de interferencia semántica en la denominación de dibujos. En los experimentos que se presentan se utilizó el procedimiento de priming enmascarado para explorar el locus del efecto de interferencia semántica. Para ello se manipuló la naturaleza de la tarea (denominación y decisión de género, el tipo de relación entre el prime y el target (semántica y fonológica y el tiempo de presentación del prime. Los resultados indicaron que el efecto de interferencia semántica aparece en las tareas de denominación (Experimento 1 y de decisión de género (Experimento 2, con tiempos de presentación del prime de 100 ms. Este resultado replica el efecto encontrado por otros investigadores y lo extiende a la tarea de decisión de género. Por otro lado, el efecto de facilitación fonológica no apareció en la tarea de decisión de género (Experimento 3. Este patrón de resultados sugiere que el efecto de interferencia semántica es consecuencia de procesos que ocurren en el nivel de representación del lemma, y que la tarea de decisión de género no está influenciada por la activación fonológica.

  18. Somatic cell genotoxicity at the glycophorin A locus in humans

    International Nuclear Information System (INIS)

    Jensen, R.H.; Grant, S.G.; Langlois, R.G.; Bigbee, W.L.

    1990-01-01

    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 OE) 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 OE 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

  19. The Contribution of Locus of Control to Academic Procrastination in Islamic Education Management Students in Indonesia

    Directory of Open Access Journals (Sweden)

    Juliana Batubara

    2017-02-01

    Full Text Available This study aimed to describe the locus of control and academic procrastination, and investigate whether there is significance contributions of locus of control on student academic procrastination. This research was conducted by the Ex post-facto method was used in this study, where the data taken from two set of questionnaires. Proportional Stratified Random Sampling was used. There were 107 students involved this study. The results showed that the locus of control is in average level, meanwhile, and the students’ academic achievement was high. The study also showed that there is a significant contribution between the locus of control on students' academic procrastination. The article concludes that the importance that locus control for procrastination research, and with suggestions for educators who work with students who are adversely affected by procrastination.

  20. Life events, locus of control, and behavioral problems among Chinese adolescents.

    Science.gov (United States)

    Liu, X; Kurita, H; Uchiyama, M; Okawa, M; Liu, L; Ma, D

    2000-12-01

    This study examined associations of life events and locus of control with behavioral problems among 1,365 Chinese adolescents by using the Youth Self-Report (YSR), Adolescent Self-Rating Life Events Checklist (ASLEC), and the Nowicki-Strickland Locus of Control Scale for Children. Results indicated that the overall prevalence of behavioral and emotional problems was 10.7% (95% CI = 9.9-11.5%). Logistic-regression analyses showed that a total of 13 negative life events mainly coming from academic domain and interpersonal relationships, high life-stress score, and high external locus score significantly increased the risk for behavioral problems. Life stress and locus of control significantly interacted with behavioral problems. These findings support the linkage between stressful life events and psychopathology in a general population of adolescents from mainland China, and demonstrate the stress-moderating effects of locus of control on psychopathology as well.

  1. How Multidimensional Health Locus of Control predicts utilization of emergency and inpatient hospital services.

    Science.gov (United States)

    Mautner, Dawn; Peterson, Bridget; Cunningham, Amy; Ku, Bon; Scott, Kevin; LaNoue, Marianna

    2017-03-01

    Health locus of control may be an important predictor of health care utilization. We analyzed associations between health locus of control and frequency of emergency department visits and hospital admissions, and investigated self-rated health as a potential mediator. Overall, 863 patients in an urban emergency department completed the Multidimensional Health Locus of Control instrument, and self-reported emergency department use and hospital admissions in the last year. We found small but significant associations between Multidimensional Health Locus of Control and utilization, all of which were mediated by self-rated health. We conclude that interventions to shift health locus of control may change patients' perceptions of their own health, thereby impacting utilization.

  2. Specific locus mutagenesis of human mammary epithelial cells by ultraviolet radiation

    International Nuclear Information System (INIS)

    Eldridge, S.R.; Gould, M.N.

    1991-01-01

    Tissue and locus specificity of mutation induction was studied in human mammary epithelial cells (HMEC). Primary HMEC from normal tissue, and immortalized HMEC (184B5) derived from normal HMEC, were cultured under identical conditions and exposed to 10J/m 2 ultraviolet (UV) radiation (254 nm peak wavelength), which produced approximately 50% mean survival in all cell strains and lines tested. UV radiation was found to induce mutations at the Na + -K + ATPase locus as determined by ouabain-resistance in both normal and immortalized HMEC. Mutation frequencies measured in these cells following UV exposure were similar to those reported for human diploid fibroblasts. Mutation induction was investigated at the hypoxanthine-guanine phosphoribosyltransferase (HPRT) locus in normal and immortalized HMEC. Induced mutations at the HPRT locus as determined by 6-thioguanine resistance in normal primary HMEC were not observed following UV radiation. Mutation induction was observed at this locus UV-exposed immortalized HMEC. (author)

  3. Organization of the cpe locus in CPE-positive clostridium perfringens type C and D isolates.

    Directory of Open Access Journals (Sweden)

    Jihong Li

    2010-06-01

    Full Text Available Clostridium perfringens enterotoxin (encoded by the cpe gene contributes to several important human, and possibly veterinary, enteric diseases. The current study investigated whether cpe locus organization in type C or D isolates resembles one of the three (one chromosomal and two plasmid-borne cpe loci commonly found amongst type A isolates. Multiplex PCR assays capable of detecting sequences in those type A cpe loci failed to amplify products from cpe-positive type C and D isolates, indicating these isolates possess different cpe locus arrangements. Therefore, restriction fragments containing the cpe gene were cloned and sequenced from two type C isolates and one type D isolate. The obtained cpe locus sequences were then used to construct an overlapping PCR assay to assess cpe locus diversity amongst other cpe-positive type C and D isolates. All seven surveyed cpe-positive type C isolates had a plasmid-borne cpe locus partially resembling the cpe locus of type A isolates carrying a chromosomal cpe gene. In contrast, all eight type D isolates shared the same plasmid-borne cpe locus, which differed substantially from the cpe locus present in other C. perfringens by containing two copies of an ORF with 67% identity to a transposase gene (COG4644 found in Tn1546, but not previously associated with the cpe gene. These results identify greater diversity amongst cpe locus organization than previously appreciated, providing new insights into cpe locus evolution. Finally, evidence for cpe gene mobilization was found for both type C and D isolates, which could explain their cpe plasmid diversity.

  4. The relationship between the INTERMED patient complexity instrument and Level of Care Utilisation System (LOCUS).

    Science.gov (United States)

    Thurber, Steven; Wilson, Ann; Realmuto, George; Specker, Sheila

    2018-03-01

    To investigate the concurrent and criterion validity of two independently developed measurement instruments, INTERMED and LOCUS, designed to improve the treatment and clinical management of patients with complex symptom manifestations. Participants (N = 66) were selected from hospital records based on the complexity of presenting symptoms, with tripartite diagnoses across biological, psychiatric and addiction domains. Biopsychosocial information from hospital records were submitted to INTERMED and LOCUS grids. In addition, Global Assessment of Functioning (GAF) ratings were gathered for statistical analyses. The product moment correlation between INTERMED and LOCUS was 0.609 (p = .01). Inverse zero-order correlations for INTERMED and LOCUS total score and GAF were obtained. However, only the beta weight for LOCUS and GAF was significant. An exploratory principal components analysis further illuminated areas of convergence between the instruments. INTERMED and LOCUS demonstrated shared variance. INTERMED appeared more sensitive to complex medical conditions and severe physiological reactions, whereas LOCUS findings are more strongly related to psychiatric symptoms. Implications are discussed.

  5. Work stress and emotional exhaustion in nurses: the mediating role of internal locus of control.

    Science.gov (United States)

    Partlak Günüşen, Neslihan; Ustün, Besti; Erdem, Sabri

    2014-01-01

    Burnout is a major problem for nursing. There is a strong relationship between work stress and emotional exhaustion. Although studies report a negative correlation between the internal locus of control and emotional exhaustion and work stress, the number of studies available on the subject is limited. This study intends to examine the extent to which the relationship between work stress and emotional exhaustion is mediated by nurses' internal locus of control. The study adopted a cross-sectional survey design. The data were analyzed using structural equation modeling techniques. The study sample consisted of 347 nurses who worked in a university hospital in Izmir, Turkey and who agreed to participate in the study. The Work-Related Strain Inventory was used to evaluate the nurses' work stress level, Maslach Burnout Inventory was used to evaluate their emotional exhaustion levels, and the Locus of Control Scale was used to evaluate the internal locus of control. The variables of the study were based on the Neuman Systems Model. Work stress was positively related to internal locus of control (β3 = .21, p 0.1). Internal locus of control was negatively related to emotional exhaustion (β = -.14, p Work stress is directly (β = .87, p Work stress is directly (β = .87, p work stress was mediated, the impact of internal locus of control was limited. It is recommended that different variables be included in future studies so that they can mediate the relationship between work stress and emotional exhaustion.

  6. The Relationship between Health Locus of Control and Health Behaviors in Emergency Medicine Personnel.

    Science.gov (United States)

    Pourhoseinzadeh, Mansour; Gheibizadeh, Mahin; Moradikalboland, Mehrnaz

    2017-10-01

    Health locus of control defined as individual beliefs based on past experiences in health issues and having external or internal control over them, could affect health. Health locus of control plays a role in health behaviors. We aimed to investigate the relationship between health locus of control and health behavior in emergency medical personnel in Ahvaz during 2016. This is a cross-sectional descriptive study, which began in August 2016 for a period of six months on 215 emergency medical personnel in Ahvaz who were selected randomly. The data were collected by a demographic questionnaire, Rotter's locus of control questionnaire, and health behavior questionnaire and analyzed using SPSS software, version 22. The correlation between variables was estimated by Pearson's correlation coefficient and independent t test. The level of significance for all statistical tests was set at 0.05. We found no significant relationship between health locus of control (external and internal) and health behavior (P>0.05).Health behaviors were very good in terms of personal health (86.5%), nutrition (53%), and sleep and rest (48.4%), and poor in terms of physical activity (52.6%) and stress management (79.5%). Furthermore, 79.5% of the emergency personnel, in general, had poor heath behaviors. Leaders and officials in the field of health must necessarily design programs in relation to health locus of control and the factors developing and affecting it as well as the role of health locus of control in doing correct behaviors.

  7. Weight loss maintenance in relation to locus of control: The MedWeight study.

    Science.gov (United States)

    Anastasiou, Costas A; Fappa, Evaggelia; Karfopoulou, Eleni; Gkza, Anastasia; Yannakoulia, Mary

    2015-08-01

    Locus of control, i.e. the degree of an individual's belief on the control of his/her life, has been related to many health outcomes, including weight loss in overweight/obese individuals. No information is available on the impact of locus of control in maintaining weight loss. We aimed to investigate the effect of locus of control in weight loss maintenance and explore potential associations with lifestyle factors. Study participants included 239 individuals (41% males) who had lost at least 10% of body weight in the past and either maintained the loss (maintainers: weight maintenance of at least 10% of initial weight) or regained it (regainers). Locus of control was defined by a relevant multi-dimensional scale; participants were categorised to internals and externals, based on "internal" and "others" sub-scales. A significant interaction was found between locus of control and weight loss maintenance status (p locus of control. Individualised treatment, according to locus of control, may increase weight loss maintenance rates in former overweight/obese individuals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Internal health locus of control predicts willingness to track health behaviors online and with smartphone applications.

    Science.gov (United States)

    Bennett, Brooke L; Goldstein, Carly M; Gathright, Emily C; Hughes, Joel W; Latner, Janet D

    2017-12-01

    Given rising technology use across all demographic groups, digital interventions offer a potential strategy for increasing access to health information and care. Research is lacking on identifying individual differences that impact willingness to use digital interventions, which may affect patient engagement. Health locus of control, the amount of control an individual believes they have over their own health, may predict willingness to use mobile health (mHealth) applications ('apps') and online trackers. A cross-sectional study (n = 276) was conducted to assess college students' health locus of control beliefs and willingness to use health apps and online trackers. Internal and powerful other health locus of control beliefs predicted willingness to use health apps and online trackers while chance health locus of control beliefs did not. Individuals with internal and powerful other health locus of control beliefs are more willing than those with chance health locus of control beliefs to utilize a form of technology to monitor or change health behaviors. Health locus of control is an easy-to-assess patient characteristic providers can measure to identify which patients are more likely to utilize mHealth apps and online trackers.

  9. Investigation of the 5q33.3 longevity locus and age-related phenotypes

    DEFF Research Database (Denmark)

    Nygaard, Marianne; Thinggaard, Mikael; Christensen, Kaare

    2017-01-01

    A large meta-analysis recently found the 5q33.3 locus to be associated with survival to ≥ 90 years and lower all-cause mortality, thus suggesting it as a third human longevity locus alongside APOE and FOXO3A. The 5q33.3 locus has previously been associated with blood pressure regulation and cardi......A large meta-analysis recently found the 5q33.3 locus to be associated with survival to ≥ 90 years and lower all-cause mortality, thus suggesting it as a third human longevity locus alongside APOE and FOXO3A. The 5q33.3 locus has previously been associated with blood pressure regulation...... and cardiovascular diseases in middle-aged individuals. However, part of the influence on mortality appears to be independent of cardiovascular phenotypes, and the role of the 5q33.3 locus in longevity and survival is therefore still partly unknown. We investigated the association between the longevity......-associated variant rs2149954 on chromosome 5q33.3 and age-related phenotypes in two cohorts of 1,588 and 1,271 long-lived individuals (mean ages 93.1 and 95.9 years, respectively) as well as in 700 middle-aged and 677 elderly individuals (mean ages 52.5 and 78.7 years). Altogether, nominally significant associations...

  10. Relationship of emotional intelligence and health locus of control among female breast cancer patients in pakistan

    International Nuclear Information System (INIS)

    Naz, R.; Kamal, A.

    2016-01-01

    Objective: To investigate relationship between emotional intelligence and health locus of control in married women with breast cancer disease. Study Design: Cross sectional study. Place and Duration of Study: The data was collected from Nuclear Oncology and Radiology Institute (NORI Hospital) Islamabad (n=210) and from Combined Military Hospital (CMH) Rawalpindi (n=101). Data collection was completed between the period from Oct 2013 to Feb 2014. Patients and Methods: The sample was selected using non- probability sampling technique. Collected breast cancer patients sample was n= 311 whose age range was from 18-80 years. A biographical sheet that contain personal and disease information of patient, and two scales were used: Self Report Measure of Emotional Intelligence (Khan and Kamal, 2010), and Multidimensional Health Locus of Control (Wallston, Stein, and Smith, 1994) were used to assess the constructs explored in this study. Results: Results depict that there was significant positive correlation between emotional intelligence (EI), including its sub scales Emotional Self-Regulation Skills (ESRS), Emotional Self Awareness Skills (ESAS), and Interpersonal Skills Scale (ISS) with the Internal Health Locus of Control (IHLOC). Doctors Health Locus of Control (DHLOC) also have significant relationship to emotional intelligence's all sub divisions, whereas external health locus of control including Chance Health Locus of Control (CHLOC) and Powerful Other people Health Locus of Control (PHLOC) both are related to psychological distresses but it was observed in breast cancer population that chance was significantly correlated to ESAS, and ISS and powerful other people locus. Further on group comparison One Way Analysis of Variance (ANOVA) depicted no significant difference on disease stage groups. Conclusion: The strength factors of EI and HLOC are highlighted in current study. It was concluded that Emotional Intelligence (EI) and health locus of control (IHLOC, and

  11. [Illness concepts of children. Validation of a modified locus of control test in illness and health].

    Science.gov (United States)

    Schmidt, A; Altmann-Herz, U

    1992-12-01

    We investigated the health and illness concepts of 53 healthy children aged 8 to 14 years using a modified illness and health locus of control scale (KKG, Lohaus and Schmitt, 1989) with the scales internal, external-p (powerful others) and external-c (chance). A comparison of the results with those on self-esteem (FSK 4-6), anxiety (CMAS-R) and hopelessness (HSC) scales showed a decrease in externality, but not an increase in internality, with increasing age and a correlation between self-confidence and a more internal locus of control. The influence of children's health locus of control on treatment compliance is discussed.

  12. [Analysis of allele dropout at TH01 locus in paternity testing].

    Science.gov (United States)

    Lai, Li; Shen, Xiao-li; Xue, Shi-jie; Hu, Jie

    2013-10-01

    To analyze allele dropout at TH01 locus in paternity testing in order to determine the accurate genotype. To use a two STR loci genotyping system to verify an abnormal genotype for the TH01 locus with PCR using specific primers, cloning and DNA sequencing. A rare allele at TH01 locus named 5.2, which was undetectable with PowerPlex 21 system, was detected with an Identifiler system. Genetic variations may result in rare alleles and loci loss. To avoid misjudgment, laboratories should have a variety of methods for detecting loci loss.

  13. HPRT gene locus mutation in peripheral blood lymphocytes induced by internal exposure to radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Jingyong, Zhao; Yongzhong, Xu; Tao, Zhao; Fengmei, Cui; Liuyi, Wang; Qinhua, Lao [Suzhou Univ., Suzhou (China). Radiation Medicine Department

    2001-07-01

    HPRT gene locus mutation in peripheral blood lymphocytes induced by internal exposure to radionuclides was performed and the relationships between mutation frequency and dose were studied. Rats were injected intravenously with radionuclides, the blood was sampled at different time after injection; HPRT gene locus mutation frequency (GMF) were examined by methods of multi-nucleus cell and Brdurd assay, working out the Dose-response function. GMF rose with the increase of dose and dose-rates and were clearly interrelated. The HPRT gene locus mutation is very sensitive to radiation and may be used as a biological dosimeter.

  14. Personal networks and locus of control in large urban centers of Argentina

    Directory of Open Access Journals (Sweden)

    Pablo De Grande

    2013-12-01

    Full Text Available This study analyzes the relationship between locus of control and interpersonal relations structures in Argentina. After a representative sample (n = 1500 of households in seven major urban centers (>200,000 inhabitants, it examines the relationship between the externality of locus of control and different aspects of personal networks of each respondent. The results show that people having more relations experiment lower levels of externality of locus of control. Likewise, lower levels of externality are informed when personal ties outside the neighborhood are available, as well as ties high educational level. In this regard, significant associations are verified between control and personal relations structures.

  15. The Schizosaccharomyces pombe JmjC-protein, Msc1, prevents H2A.Z localization in centromeric and subtelomeric chromatin domains.

    Directory of Open Access Journals (Sweden)

    Luke Buchanan

    2009-11-01

    Full Text Available Eukaryotic genomes are repetitively packaged into chromatin by nucleosomes, however they are regulated by the differences between nucleosomes, which establish various chromatin states. Local chromatin cues direct the inheritance and propagation of chromatin status via self-reinforcing epigenetic mechanisms. Replication-independent histone exchange could potentially perturb chromatin status if histone exchange chaperones, such as Swr1C, loaded histone variants into wrong sites. Here we show that in Schizosaccharomyces pombe, like Saccharomyces cerevisiae, Swr1C is required for loading H2A.Z into specific sites, including the promoters of lowly expressed genes. However S. pombe Swr1C has an extra subunit, Msc1, which is a JumonjiC-domain protein of the Lid/Jarid1 family. Deletion of Msc1 did not disrupt the S. pombe Swr1C or its ability to bind and load H2A.Z into euchromatin, however H2A.Z was ectopically found in the inner centromere and in subtelomeric chromatin. Normally this subtelomeric region not only lacks H2A.Z but also shows uniformly lower levels of H3K4me2, H4K5, and K12 acetylation than euchromatin and disproportionately contains the most lowly expressed genes during vegetative growth, including many meiotic-specific genes. Genes within and adjacent to subtelomeric chromatin become overexpressed in the absence of either Msc1, Swr1, or paradoxically H2A.Z itself. We also show that H2A.Z is N-terminally acetylated before, and lysine acetylated after, loading into chromatin and that it physically associates with the Nap1 histone chaperone. However, we find a negative correlation between the genomic distributions of H2A.Z and Nap1/Hrp1/Hrp3, suggesting that the Nap1 chaperones remove H2A.Z from chromatin. These data describe H2A.Z action in S. pombe and identify a new mode of chromatin surveillance and maintenance based on negative regulation of histone variant misincorporation.

  16. Meiosis-specific cohesin component, Stag3 is essential for maintaining centromere chromatid cohesion, and required for DNA repair and synapsis between homologous chromosomes.

    Science.gov (United States)

    Hopkins, Jessica; Hwang, Grace; Jacob, Justin; Sapp, Nicklas; Bedigian, Rick; Oka, Kazuhiro; Overbeek, Paul; Murray, Steve; Jordan, Philip W

    2014-07-01

    Cohesins are important for chromosome structure and chromosome segregation during mitosis and meiosis. Cohesins are composed of two structural maintenance of chromosomes (SMC1-SMC3) proteins that form a V-shaped heterodimer structure, which is bridged by a α-kleisin protein and a stromal antigen (STAG) protein. Previous studies in mouse have shown that there is one SMC1 protein (SMC1β), two α-kleisins (RAD21L and REC8) and one STAG protein (STAG3) that are meiosis-specific. During meiosis, homologous chromosomes must recombine with one another in the context of a tripartite structure known as the synaptonemal complex (SC). From interaction studies, it has been shown that there are at least four meiosis-specific forms of cohesin, which together with the mitotic cohesin complex, are lateral components of the SC. STAG3 is the only meiosis-specific subunit that is represented within all four meiosis-specific cohesin complexes. In Stag3 mutant germ cells, the protein level of other meiosis-specific cohesin subunits (SMC1β, RAD21L and REC8) is reduced, and their localization to chromosome axes is disrupted. In contrast, the mitotic cohesin complex remains intact and localizes robustly to the meiotic chromosome axes. The instability of meiosis-specific cohesins observed in Stag3 mutants results in aberrant DNA repair processes, and disruption of synapsis between homologous chromosomes. Furthermore, mutation of Stag3 results in perturbation of pericentromeric heterochromatin clustering, and disruption of centromere cohesion between sister chromatids during meiotic prophase. These defects result in early prophase I arrest and apoptosis in both male and female germ cells. The meiotic defects observed in Stag3 mutants are more severe when compared to single mutants for Smc1β, Rec8 and Rad21l, however they are not as severe as the Rec8, Rad21l double mutants. Taken together, our study demonstrates that STAG3 is required for the stability of all meiosis-specific cohesin

  17. Meiosis-specific cohesin component, Stag3 is essential for maintaining centromere chromatid cohesion, and required for DNA repair and synapsis between homologous chromosomes.

    Directory of Open Access Journals (Sweden)

    Jessica Hopkins

    2014-07-01

    Full Text Available Cohesins are important for chromosome structure and chromosome segregation during mitosis and meiosis. Cohesins are composed of two structural maintenance of chromosomes (SMC1-SMC3 proteins that form a V-shaped heterodimer structure, which is bridged by a α-kleisin protein and a stromal antigen (STAG protein. Previous studies in mouse have shown that there is one SMC1 protein (SMC1β, two α-kleisins (RAD21L and REC8 and one STAG protein (STAG3 that are meiosis-specific. During meiosis, homologous chromosomes must recombine with one another in the context of a tripartite structure known as the synaptonemal complex (SC. From interaction studies, it has been shown that there are at least four meiosis-specific forms of cohesin, which together with the mitotic cohesin complex, are lateral components of the SC. STAG3 is the only meiosis-specific subunit that is represented within all four meiosis-specific cohesin complexes. In Stag3 mutant germ cells, the protein level of other meiosis-specific cohesin subunits (SMC1β, RAD21L and REC8 is reduced, and their localization to chromosome axes is disrupted. In contrast, the mitotic cohesin complex remains intact and localizes robustly to the meiotic chromosome axes. The instability of meiosis-specific cohesins observed in Stag3 mutants results in aberrant DNA repair processes, and disruption of synapsis between homologous chromosomes. Furthermore, mutation of Stag3 results in perturbation of pericentromeric heterochromatin clustering, and disruption of centromere cohesion between sister chromatids during meiotic prophase. These defects result in early prophase I arrest and apoptosis in both male and female germ cells. The meiotic defects observed in Stag3 mutants are more severe when compared to single mutants for Smc1β, Rec8 and Rad21l, however they are not as severe as the Rec8, Rad21l double mutants. Taken together, our study demonstrates that STAG3 is required for the stability of all meiosis

  18. Molecular studies of deletions at the human steroid sulfatase locus

    International Nuclear Information System (INIS)

    Shapiro, L.J.; Yen, P.; Pomerantz, D.; Martin, E.; Rolewic, L.; Mohandas, T.

    1989-01-01

    The human steroid sulfatase gene (STS) is located on the distal X chromosome short arm close to the pseudoautosomal region but in a segment of DNA that is unique to the X chromosome. In contrast to most X chromosome-encoded genes, STS expression is not extinguished during the process of X chromosome inactivation. Deficiency of STS activity produced the syndrome of X chromosome-linked ichthyosis, which is one of the most common inborn errors of metabolism in man. Approximately 90% of STS - individuals have large deletions at the STS locus. The authors and others have found that the end points of such deletions are heterogeneous in their location. One recently ascertained subject was observed to have a 40-kilobase deletion that is entirely intragenic, permitting the cloning and sequencing of the deletion junction. Studies of this patient and of other X chromosome sequences in other subjects permit some insight into the mechanism(s) responsible for generating frequent deletions on the short arm of the X chromosome

  19. Characterization of mutations at the mouse phenylalanine hydroxylase locus

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, J.D.; Charlton, C.K. [Wichita State Univ., KS (United States)

    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.

  20. Locus coeruleus and dopaminergic consolidation of everyday memory

    Science.gov (United States)

    Takeuchi, Tomonori; Duszkiewicz, Adrian J.; Sonneborn, Alex; Spooner, Patrick A.; Yamasaki, Miwako; Watanabe, Masahiko; Smith, Caroline C.; Fernández, Guillén; Deisseroth, Karl; Greene, Robert W.; Morris, Richard G. M.

    2016-01-01

    Summary The retention of episodic-like memory is enhanced, in humans and animals, when something novel happens shortly before or after encoding. Using an everyday memory task in mice, we sought the neurons mediating this dopamine-dependent novelty effect, previously thought to originate exclusively from the tyrosine hydroxylase-expressing (TH+) neurons in the ventral tegmental area (VTA). We report that neuronal firing in the locus coeruleus (LC) is especially sensitive to environmental novelty, LC-TH+ neurons project more profusely than VTA-TH+ neurons to the hippocampus, optogenetic activation of LC-TH+ neurons mimics the novelty effect, and this novelty-associated memory enhancement is unaffected by VTA inactivation. Surprisingly, two effects of LC-TH+ photoactivation are sensitive to hippocampal D1/D5 receptor blockade and resistant to adrenoceptors blockade – memory enhancement and long lasting potentiation of synaptic transmission in CA1 ex vivo. Thus, LC-TH+ neurons can mediate post-encoding memory enhancement in a manner consistent with possible co-release of dopamine in hippocampus. PMID:27602521

  1. Vocational interests of adolescents: relationships between self-esteem and locus of control.

    Science.gov (United States)

    Mullis, A K; Mullis, R L

    1997-12-01

    The purpose of this study was to examine relationships among scores on vocational interests, self-esteem, and locus of control for high school students. Grade and sex differences were also examined. 1364 high school students ranging in age from 14 to 19 years of age were administered the Coopersmith Self-esteem Inventory, Nowicki-Strickland Locus of Control Scale for Children, and the Strong-Campbell Interest Inventory. High school students with higher scores on self-esteem and showing an orientation toward internal locus of control expressed more interests in a variety of vocational themes than adolescents with lower scores on self-esteem and scores for external locus of control. Sex and grade differences in vocational interests of adolescents were also noted. The findings were discussed in light of theoretical and practical considerations.

  2. Analysis of an "off-ladder" allele at the Penta D short tandem repeat locus.

    Science.gov (United States)

    Yang, Y L; Wang, J G; Wang, D X; Zhang, W Y; Liu, X J; Cao, J; Yang, S L

    2015-11-25

    Kinship testing of a father and his son from Guangxi, China, the location of the Zhuang minority people, was performed using the PowerPlex® 18D System with a short tandem repeat typing kit. The results indicated that both the father and his son had an off-ladder allele at the Penta D locus, with a genetic size larger than that of the maximal standard allelic ladder. To further identify this locus, monogenic amplification, gene cloning, and genetic sequencing were performed. Sequencing analysis demonstrated that the fragment size of the Penta D-OL locus was 469 bp and the core sequence was [AAAGA]21, also called Penta D-21. The rare Penta D-21 allele was found to be distributed among the Zhuang population from the Guangxi Zhuang Autonomous Region of China; therefore, this study improved the range of DNA data available for this locus and enhanced our ability for individual identification of gene loci.

  3. A novel locus for dilated cardiomyopathy maps to canine chromosome 8.

    Science.gov (United States)

    Werner, Petra; Raducha, Michael G; Prociuk, Ulana; Sleeper, Meg M; Van Winkle, Thomas J; Henthorn, Paula S

    2008-06-01

    Dilated cardiomyopathy (DCM), the most common form of cardiomyopathy, often leads to heart failure and sudden death. While a substantial proportion of DCMs are inherited, mutations responsible for the majority of DCMs remain unidentified. A genome-wide linkage study was performed to identify the locus responsible for an autosomal recessive inherited form of juvenile DCM (JDCM) in Portuguese water dogs using 16 families segregating the disease. Results link the JDCM locus to canine chromosome 8 with two-point and multipoint lod scores of 10.8 and 14, respectively. The locus maps to a 3.9-Mb region, with complete syntenic homology to human chromosome 14, that contains no genes or loci known to be involved in the development of any type of cardiomyopathy. This discovery of a DCM locus with a previously unknown etiology will provide a new gene to examine in human DCM patients and a model for testing therapeutic approaches for heart failure.

  4. RAS1, a quantitative trait locus for salt tolerance and ABA sensitivity in Arabidopsis

    KAUST Repository

    Ren, Zhonghai; Zheng, Zhimin; Chinnusamy, Viswanathan; Zhu, Jianhua; Cui, Xinping; Iida, Kei; Zhu, Jian-Kang

    2010-01-01

    Soil salinity limits agricultural production and is a major obstacle for feeding the growing world population. We used natural genetic variation in salt tolerance among different Arabidopsis accessions to map a major quantitative trait locus (QTL

  5. Relationship among prospective parents' locus of control, social desirability, and choice of psychoprophylaxis.

    Science.gov (United States)

    Windwer, C

    1977-01-01

    This study sought to determine if there is a relationship among locus of control, social desirability, and choice of psychoprophylaxis (PPM). It was hypothesized that internal locus of control and low social desirability would correlate significantly with the choice of PPM by husbands and wives; that externally controlled wives who participated in PPM would have more internally controlled husbands than externally controlled wives who participated in PPM would have more internally controlled husbands than externally controlled wives who did not participate; and that locus of control and social desirability, when taken together, would be better predictors of choice of PPM than either taken separately. Ninety-eight middle-class nulliparous couples, participant and non-participant, were studied in the seventh or eighth month of the wife's pregnancy. Rotter's I-E Scale and the Marlowe-Crowne Social Desirability Scale were used to measure locus of control and social desirability. Study findings did not support the hypotheses.

  6. Adult self-esteem and locus of control as a function of familial alcoholism and dysfunction.

    Science.gov (United States)

    Werner, L J; Broida, J P

    1991-05-01

    This study examines self-esteem and locus of control in adult children of alcoholics. We assessed these measures in 195 professional adults in relation to alcoholism and functioning in the family of origin. Although the presence of parental alcoholism was not a predictor of significant differences in adult self-esteem or locus of control, familial dysfunction was reflected in significant differences in self-esteem. This suggests that parental alcoholism does not necessarily result in personality differences in adult children.

  7. Relationship between Dental Anxiety and Health Locus of Control among Physiotherapy Students

    Directory of Open Access Journals (Sweden)

    Pooja Agarwal

    2013-01-01

    Materials & Method: A total of 152 students participated in the study. Dental anxiety was assessed using the 5 item Modified Dental Anxiety Scale (MDAS and Locus of Control was assessed using the 18 item Multidimensional Health Locus of Control (MHLC scale. Results: A Statistically significant positive correlation was found between the internal dimension of MHLC and dental anxiety. Conclusions: HLC was found to play an important role in predicting the dental anxiety among physiotherapy students.

  8. Health locus of control: Its relationship with medication adherence and medication wastage.

    Science.gov (United States)

    West, Lorna Marie; Borg Theuma, Ruth; Cordina, Maria

    2017-12-09

    Non-adherence is a significant factor contributing to medication wastage. Whilst there is some evidence on the influence of patients' health locus of control in relation to adherence, there has been little inquiry into its relationship with mediation wastage. To determine the relationship between medication adherence and health locus of control as well as medication wastage and health locus of control in patients with chronic conditions. Outpatients having a diagnosis of asthma, cardiovascular conditions, or diabetes participated in a cross-sectional study employing a self-administered questionnaire. The questionnaire determined presence of unused medication (wastage), adherence using 'Tool for Adherence Behaviour Screening' (TABS), and health locus of control using 'Multidimensional Health Locus of Control' (MHLC) scale Form C. Logistic regression was performed to ascertain the effects of MHLC and demographics in relation to adherence and wastage. MHLC beliefs were divided into 8 types of health locus of control. One-Way ANOVA was used to assess differences between conditions and belief types. P-values ≤ .05 were considered significant. There were 330 patients recruited (58% male; age, mean±(SD): 61 ± 15 years; 110 asthma, 110 cardiovascular, 110 diabetes). In terms of health locus of control, females had higher 'doctors' beliefs (p = .054) and significantly lower 'other people' beliefs (p = control. 'Yea-sayers' had the least presence of unused medication, followed by 'pure internal' believers. 'Pure powerful others external' had the highest presence of unused medication. Healthcare professionals should take into account patients' health locus of control beliefs whilst conducting an intervention with patients; this can impact positively medication adherence and minimisation of medication wastage. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. The effect of high and low assertiveness on locus of control and health problems.

    Science.gov (United States)

    Williams, J M; Stout, J K

    1985-03-01

    The effect of high and low assertiveness on locus of control and health problems was examined with 78 direct-service workers in mental health and mental retardation settings in northeastern Pennsylvania. The direct-service workers completed the Rathus (1973) Assertiveness Schedule, the Rotter (1966) Internal-External Locus of Control Scale, and a health-problems inventory. Highly assertive individuals were found to be more internally controlled and to experience fewer health problems than were individuals low in assertiveness.

  10. Prevalence of Porphyromonas gingivalis Four rag Locus Genotypes in Patients of Orthodontic Gingivitis and Periodontitis

    Science.gov (United States)

    Liu, Yi; Zhang, Yujie; Wang, Lili; Guo, Yang; Xiao, Shuiqing

    2013-01-01

    Porphyromonas gingivalis is considered as a major etiological agent in periodontal diseases and implied to result in gingival inflammation under orthodontic appliance. rag locus is a pathogenicity island found in Porphyromonas gingivalis. Four rag locus variants are different in pathogenicity of Porphyromonas gingivalis. Moreover, there are different racial and geographic differences in distribution of rag locus genotypes. In this study, we assessed the prevalence of Porphyromonas gingivalis and rag locus genotypes in 102 gingival crevicular fluid samples from 57 cases of gingivitis patients with orthodontic appliances, 25 cases of periodontitis patients and 20 cases of periodontally healthy people through a 16S rRNA-based PCR and a multiplex PCR. The correlations between Porphyromona.gingivalis/rag locus and clinical indices were analyzed. The prevalence of Porphyromonas gingivalis and rag locus genes in periodontitis group was the highest among three groups and higher in orthodontic gingivitis than healthy people (porthodontic gingivitis and mild-to-moderate periodontitis in Shandong. Porphyromonas.gingivalis carrying rag-1 has the strong virulence and could be associated with severe periodontitis. PMID:23593379

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

    Science.gov (United States)

    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.

  12. Social capital, political trust, and health locus of control: a population-based study.

    Science.gov (United States)

    Lindström, Martin

    2011-02-01

    To investigate the association between political trust in the Riksdag and lack of belief in the possibility to influence one's own health (external locus of control), taking horizontal trust into account. The 2008 public health survey in Skåne is a cross-sectional postal questionnaire study with a 55% participation rate. A random sample of 28,198 persons aged 18-80 years participated. Logistic regression models were used to investigate the associations between political trust in the Riksdag (an aspect of vertical trust) and lack of belief in the possibility to influence one's own health (external locus of control). The multiple regression analyses included age, country of birth, education, and horizontal trust in other people. A 33.7% of all men and 31.8% of all women lack internal locus of control. Low (external) health locus of control is more common in higher age groups, among people born outside Sweden, with lower education, low horizontal trust, low political trust, and no opinion concerning political trust. Respondents with not particularly strong political trust, no political trust at all and no opinion have significantly higher odds ratios of external locus of control throughout the multiple regression analyses. Low political trust in the Riksdag seems to be independently associated with external health locus of control.

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

    Science.gov (United States)

    Sussman, Harvey M.; Modarresi, Golnaz

    2004-05-01

    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.

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

    Science.gov (United States)

    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.

  15. Physical map and one-megabase sequencing of the human immunoglobulin lambda locus

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    Geraldo A.S. Passos Jr.

    1998-06-01

    Full Text Available The human immunoglobulin lambda (IGL locus is located on chromosome 22q11.1-q11.2 and contains the genes responsible for the immunoglobulin lambda light chains. This locus was recently mapped (physical map and its 1-Mb DNA totally sequenced. In this review we focus on the characterization of the v-lambda genes, its chromosomal location, genomics and sequencing of the IGL locus.O locus IGL humano está localizado no cromosomo 22q11.1-q11.2 e contém os genes responsáveis pelas cadeias leves de imunoglobulina tipo lambda. Este locus foi recentemente mapeado (mapa físico e seu 1 Mb DNA totalmente sequenciado. Nesta revisão focamos os principais resultados de caracterização dos genes v-lambda, sua localização cromossômica, a genômica e seqüenciamento do locus IGL.

  16. Identification of a novel locus for a USH3 like syndrome combined with congenital cataract.

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    Dad, S; Østergaard, E; Thykjaer, T; Albrectsen, A; Ravn, K; Rosenberg, T; Møller, L B

    2010-10-01

    Usher syndrome (USH) is the most common genetic disease that causes both deafness and blindness. USH is divided into three types, USH1, USH2 and USH3, depending on the age of onset, the course of the disease, and on the degree of vestibular dysfunction. By homozygosity mapping of a consanguineous Danish family of Dutch descent, we have identified a novel locus for a rare USH3-like syndrome. The affected family members have a unique association of retinitis pigmentosa, progressive hearing impairment, vestibular dysfunction, and congenital cataract. The phenotype is similar, but not identical to that of USH3 patients, as congenital cataract has not been reported for USH3. By homozygosity mapping, we identified a 7.3 Mb locus on chromosome 15q22.2-23 with a maximum multipoint LOD score of 2.0. The locus partially overlaps with the USH1 locus, USH1H, a novel unnamed USH2 locus, and the non-syndromic deafness locus DFNB48. © 2010 John Wiley & Sons A/S.

  17. Fine mapping of the NRG1 Hirschsprung's disease locus.

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    Clara Sze-Man Tang

    Full Text Available The primary pathology of Hirschsprung's disease (HSCR, colon aganglionosis is the absence of ganglia in variable lengths of the hindgut, resulting in functional obstruction. HSCR is attributed to a failure of migration of the enteric ganglion precursors along the developing gut. RET is a key regulator of the development of the enteric nervous system (ENS and the major HSCR-causing gene. Yet the reduced penetrance of RET DNA HSCR-associated variants together with the phenotypic variability suggest the involvement of additional genes in the disease. Through a genome-wide association study, we uncovered a ∼350 kb HSCR-associated region encompassing part of the neuregulin-1 gene (NRG1. To identify the causal NRG1 variants contributing to HSCR, we genotyped 243 SNPs variants on 343 ethnic Chinese HSCR patients and 359 controls. Genotype analysis coupled with imputation narrowed down the HSCR-associated region to 21 kb, with four of the most associated SNPs (rs10088313, rs10094655, rs4624987, and rs3884552 mapping to the NRG1 promoter. We investigated whether there was correlation between the genotype at the rs10088313 locus and the amount of NRG1 expressed in human gut tissues (40 patients and 21 controls and found differences in expression as a function of genotype. We also found significant differences in NRG1 expression levels between diseased and control individuals bearing the same rs10088313 risk genotype. This indicates that the effects of NRG1 common variants are likely to depend on other alleles or epigenetic factors present in the patients and would account for the variability in the genetic predisposition to HSCR.

  18. The 4q27 locus and prostate cancer risk

    International Nuclear Information System (INIS)

    Tindall, Elizabeth A; Hoang, Hoa N; Southey, Melissa C; English, Dallas R; Hopper, John L; Giles, Graham G; Severi, Gianluca; Hayes, Vanessa M

    2010-01-01

    Chronic inflammation is considered to be implicated in the development of prostate cancer. In this study we are the first to investigate a potential association between variants in an autoimmune related region on chromosome 4q27 and prostate cancer risk. This region harbors two cytokine genes IL-2 and the recently described IL-21. We genotyped six variants previously associated with autoimmune disease (namely rs13151961, rs13119723, rs17388568, rs3136534, rs6822844 and rs6840978) and one functional IL-2 promoter variant (rs2069762) for possible association with prostate cancer risk using the Australian Risk Factors for Prostate Cancer case-control Study. Overall, our results do not support an association between the seven variants at position 4q27 and prostate cancer risk. Per allele odds ratios (ORs) were not significantly different from 1 (all P-values = 0.06). However, we found suggestive evidence for a significant association between the presence of the rs13119723 variant (located in a protein of unknown function) and men with a family history of prostate cancer in first-degree relatives (P-value for interaction 0.02). The per allele OR associated with this variant was significantly higher than 1 (2.37; 95% C.I. = 1.01-5.57). We suggest that genetic variation within the chromosome 4q27 locus might be associated with prostate cancer susceptibility in men with a family history of the disease. Furthermore, our study alludes to a potential role of unknown protein KIAA1109 in conferring this risk

  19. Variants at the 9p21 locus and melanoma risk

    International Nuclear Information System (INIS)

    Maccioni, Livia; Rachakonda, Panduranga Sivaramakrishna; Bermejo, Justo Lorenzo; Planelles, Dolores; Requena, Celia; Hemminki, Kari; Nagore, Eduardo; Kumar, Rajiv

    2013-01-01

    The influence of variants at the 9p21 locus on melanoma risk has been reported through investigation of CDKN2A variants through candidate gene approach as well as by genome wide association studies (GWAS). In the present study we genotyped, 25 SNPs that tag 273 variants on chromosome 9p21 in 837 melanoma cases and 1154 controls from Spain. Ten SNPs were selected based on previous associations, reported in GWAS, with either melanocytic nevi or melanoma risk or both. The other 15 SNPs were selected to fine map the CDKN2A gene region. All the 10 variants selected from the GWAS showed statistically significant association with melanoma risk. Statistically significant association with melanoma risk was also observed for the carriers of the variant T-allele of rs3088440 (540 C>T) at the 3’ UTR of CDKN2A gene with an OR 1.52 (95% CI 1.14-2.04). Interaction analysis between risk associated polymorphisms and previously genotyped MC1R variants, in the present study, did not show any statistically significant association. Statistical significant association was observed for the interaction between phototypes and the rs10811629 (located in intron 5 of MTAP). The strongest association was observed between the homozygous carrier of the A–allele and phototype II with an OR of 15.93 (95% CI 5.34-47.54). Our data confirmed the association of different variants at chromosome 9p21 with melanoma risk and we also found an association of a variant with skin phototypes

  20. Genomic Locus Modulating IOP in the BXD RI Mouse Strains

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    Rebecca King

    2018-05-01

    Full Text Available Intraocular pressure (IOP is the primary risk factor for developing glaucoma, yet little is known about the contribution of genomic background to IOP regulation. The present study leverages an array of systems genetics tools to study genomic factors modulating normal IOP in the mouse. The BXD recombinant inbred (RI strain set was used to identify genomic loci modulating IOP. We measured the IOP in a total of 506 eyes from 38 different strains. Strain averages were subjected to conventional quantitative trait analysis by means of composite interval mapping. Candidate genes were defined, and immunohistochemistry and quantitative PCR (qPCR were used for validation. Of the 38 BXD strains examined the mean IOP ranged from a low of 13.2mmHg to a high of 17.1mmHg. The means for each strain were used to calculate a genome wide interval map. One significant quantitative trait locus (QTL was found on Chr.8 (96 to 103 Mb. Within this 7 Mb region only 4 annotated genes were found: Gm15679, Cdh8, Cdh11 and Gm8730. Only two genes (Cdh8 and Cdh11 were candidates for modulating IOP based on the presence of non-synonymous SNPs. Further examination using SIFT (Sorting Intolerant From Tolerant analysis revealed that the SNPs in Cdh8 (Cadherin 8 were predicted to not change protein function; while the SNPs in Cdh11 (Cadherin 11 would not be tolerated, affecting protein function. Furthermore, immunohistochemistry demonstrated that CDH11 is expressed in the trabecular meshwork of the mouse. We have examined the genomic regulation of IOP in the BXD RI strain set and found one significant QTL on Chr. 8. Within this QTL, there is one good candidate gene, Cdh11.

  1. Locus-specific ribosomal RNA gene silencing in nucleolar dominance.

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    Michelle S Lewis

    2007-08-01

    Full Text Available The silencing of one parental set of rRNA genes in a genetic hybrid is an epigenetic phenomenon known as nucleolar dominance. We showed previously that silencing is restricted to the nucleolus organizer regions (NORs, the loci where rRNA genes are tandemly arrayed, and does not spread to or from neighboring protein-coding genes. One hypothesis is that nucleolar dominance is the net result of hundreds of silencing events acting one rRNA gene at a time. A prediction of this hypothesis is that rRNA gene silencing should occur independent of chromosomal location. An alternative hypothesis is that the regulatory unit in nucleolar dominance is the NOR, rather than each individual rRNA gene, in which case NOR localization may be essential for rRNA gene silencing. To test these alternative hypotheses, we examined the fates of rRNA transgenes integrated at ectopic locations. The transgenes were accurately transcribed in all independent transgenic Arabidopsis thaliana lines tested, indicating that NOR localization is not required for rRNA gene expression. Upon crossing the transgenic A. thaliana lines as ovule parents with A. lyrata to form F1 hybrids, a new system for the study of nucleolar dominance, the endogenous rRNA genes located within the A. thaliana NORs are silenced. However, rRNA transgenes escaped silencing in multiple independent hybrids. Collectively, our data suggest that rRNA gene activation can occur in a gene-autonomous fashion, independent of chromosomal location, whereas rRNA gene silencing in nucleolar dominance is locus-dependent.

  2. Polymorphisms in steroid hormone biosynthesis genes and risk of breast cancer and fibrocystic breast conditions in Chinese women.

    Science.gov (United States)

    Sakoda, Lori C; Blackston, Christie; Doherty, Jennifer A; Ray, Roberta M; Lin, Ming Gang; Stalsberg, Helge; Gao, Dao Li; Feng, Ziding; Thomas, David B; Chen, Chu

    2008-05-01

    Common variants in genes encoding for key enzymes involved in steroidogenesis may alter sex steroid hormone levels, thereby influencing susceptibility to breast carcinoma and related conditions. In a case-control study of Chinese women, we examined genotypes of the CYP11A1 pentanucleotide [(TAAAA)n] repeat (D15S520), CYP17A1 rs743572, and HSD17B1 rs605059 polymorphisms in relation to the risk of breast cancer and fibrocystic breast conditions, comparing 615 women with breast cancer and 467 women with fibrocystic breast conditions separately with 879 women without clinical breast disease. We also evaluated whether these relationships differed by the presence of proliferation in the extratumoral epithelium or fibrocystic lesions, menopausal status, or body mass index. Only CYP11A1 genotype was related to breast cancer risk, with women homozygous for the 4-repeat allele, relative to those homozygous for the 6-repeat allele, at reduced risk (age-adjusted odds ratio, 0.58; 95% confidence interval, 0.37-0.91). There was some suggestion of a stronger inverse association for breast cancer with evidence of proliferation in the extratumoral epithelium than for breast cancer without extratumoral proliferation. Breast cancer risk associated with CYP11A1 genotype did not differ by menopausal status or body mass index level. No associations between CYP11A1, CYP17A1, and HSD17B1 genotypes and risk of fibrocystic breast conditions were observed. Our findings support the possibility that common allelic variation at the CYP11A1 D15S520 locus alters breast cancer risk in Chinese women.

  3. Effectiveness of teaching cognitive-behavioral techniques on locus of control in hemodialysis patients.

    Science.gov (United States)

    Mehrtak, Mohammad; Habibzadeh, Shahram; Farzaneh, Esmaeil; Rjaei-Khiavi, Abdollah

    2017-10-01

    Many of the cognitive behavioral models and therapeutic protocols developed so far for psychological disorders and chronic diseases have proved effective through clinical research. This study aimed to determine the effectiveness of teaching cognitive-behavioral techniques on locus of control in hemodialysis patients. This controlled clinical trial study was conducted in 2015 with 76 patients selected by census and treated with a hemodialysis machine in the dialysis department of Vali-Asr Hospital in the city of Meshkinshahr. A total of four patients were excluded because of their critical conditions while the rest, who were recruited, were randomly divided into two equal groups of 36 patients as the intervention and control groups. First, the locus of control was measured in both groups through a pretest, and cognitive-behavioral techniques were then taught to the intervention group during eight 45 to 90-minute sessions. The locus of control in patients of both groups was finally re-measured through a posttest. Data were collected using Rotter's Locus of Control Inventory. The Wilcoxon test and Mann-Whitney U test were respectively used in SPSS18 for data analysis. In the pretest and posttest stages respectively, 4.8% and 14.3% of samples in the control group as well as 14.3% and 33.3% of samples in the intervention group enjoyed internal locus of control. The difference between the pretest and posttest scores of internal locus of control in the intervention group was significant (p=0.004), which indicates the positive effect of cognitive-behavioral psychotherapeutic intervention on internalization of locus of control in this group. Given the external locus of control in most of the study patients and also the positive significant effect of cognitive-behavioral psychotherapy on internalization of locus of control in this group of patients, it appears necessary to have a psychology resident present in the hemodialysis department to teach the necessary cognitive

  4. Genetic mapping of the female mimic morph locus in the ruff

    Science.gov (United States)

    2013-01-01

    Background Ruffs (Aves: Philomachus pugnax) possess a genetic polymorphism for male mating behaviour resulting in three permanent alternative male reproductive morphs: (i) territorial ‘Independents’, (ii) non-territorial ‘Satellites’, and (iii) female-mimicking ‘Faeders’. Development into independent or satellite morphs has previously been shown to be due to a single-locus, two-allele autosomal Mendelian mode of inheritance at the Satellite locus. Here, we use linkage analysis to map the chromosomal location of the Faeder locus, which controls development into the Faeder morph, and draw further conclusions about candidate genes, assuming shared synteny with other birds. Results Segregation data on the Faeder locus were obtained from captive-bred pedigrees comprising 64 multi-generation families (N = 381). There was no evidence that the Faeder locus was linked to the Satellite locus, but it was linked with microsatellite marker Ppu020. Comparative mapping of ruff microsatellite markers against the chicken (Gallus gallus) and zebra finch (Taeniopygia guttata) genomes places the Ppu020 and Faeder loci on a region of chromosome 11 that includes the Melanocortin-1 receptor (MC1R) gene, which regulates colour polymorphisms in numerous birds and other vertebrates. Melanin-based colouration varies with life-history strategies in ruffs and other species, thus the MC1R gene is a strong candidate to play a role in alternative male morph determination. Conclusion Two unlinked loci appear to control behavioural development in ruffs. The Faeder locus is linked to Ppu020, which, assuming synteny, is located on avian chromosome 11. MC1R is a candidate gene involved in alternative male morph determination in ruffs. PMID:24256185

  5. Maxwell Strata and Cut Locus in the Sub-Riemannian Problem on the Engel Group

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    Ardentov, Andrei A.; Sachkov, Yuri L.

    2017-12-01

    We consider the nilpotent left-invariant sub-Riemannian structure on the Engel group. This structure gives a fundamental local approximation of a generic rank 2 sub-Riemannian structure on a 4-manifold near a generic point (in particular, of the kinematic models of a car with a trailer). On the other hand, this is the simplest sub-Riemannian structure of step three. We describe the global structure of the cut locus (the set of points where geodesics lose their global optimality), the Maxwell set (the set of points that admit more than one minimizer), and the intersection of the cut locus with the caustic (the set of conjugate points along all geodesics). The group of symmetries of the cut locus is described: it is generated by a one-parameter group of dilations R+ and a discrete group of reflections Z2 × Z2 × Z2. The cut locus admits a stratification with 6 three-dimensional strata, 12 two-dimensional strata, and 2 one-dimensional strata. Three-dimensional strata of the cut locus are Maxwell strata of multiplicity 2 (for each point there are 2 minimizers). Two-dimensional strata of the cut locus consist of conjugate points. Finally, one-dimensional strata are Maxwell strata of infinite multiplicity, they consist of conjugate points as well. Projections of sub-Riemannian geodesics to the 2-dimensional plane of the distribution are Euler elasticae. For each point of the cut locus, we describe the Euler elasticae corresponding to minimizers coming to this point. Finally, we describe the structure of the optimal synthesis, i. e., the set of minimizers for each terminal point in the Engel group.

  6. Detailed mapping of a resistance locus against Fusarium wilt in cultivated eggplant (Solanum melongena).

    Science.gov (United States)

    Miyatake, Koji; Saito, Takeo; Negoro, Satomi; Yamaguchi, Hirotaka; Nunome, Tsukasa; Ohyama, Akio; Fukuoka, Hiroyuki

    2016-02-01

    This is the first report on genetic mapping of a resistance locus against Fusarium wilt caused by the plant pathogen Fusarium oxysporum f. sp. melongenae in cultivated eggplant. Fusarium wilt, caused by the plant pathogen Fusarium oxysporum f. sp. melongenae, is a major soil-borne disease threatening stable production in eggplant (Solanum melongena). Although three eggplant germplasms, LS1934, LS174, and LS2436, are known to be highly resistant to the pathogen, their resistance loci have not been mapped. In this study, we performed quantitative trait locus analyses in F2:3 populations and detected a resistance locus, FM1, at the end of chromosome 2, with two alleles, Fm1(L) and Fm1(E), in the F2 populations LWF2 [LS1934 × WCGR112-8 (susceptible)] and EWF2 [EPL-1 (derived from LS174) × WCGR112-8], respectively. The percentage of phenotypic variance explained by Fm1(L) derived from LS1934 was 75.0% [Logarithm of the odds (LOD) = 29.3], and that explained by Fm1(E) derived from EPL-1 was 92.2% (LOD = 65.8). Using backcrossed inbred lines, we mapped FM1 between two simple sequence repeat markers located ~4.881 cM apart from each other. Comparing the location of the above locus to those of previously reported ones, the resistance locus Rfo-sa1 from an eggplant ally (Solanum aethiopicum gr. Gilo) was mapped very close to FM1, whereas another resistance locus, from LS2436, was mapped to the middle of chromosome 4. This is the first report of mapping of a Fusarium resistance locus in cultivated eggplant. The availability of resistance-linked markers will enable the application of marker-assisted selection to overcome problems posed by self-incompatibility and introduction of negative traits because of linkage drag, and will lead to clear understanding of genetic mechanism of Fusarium resistance.

  7. Participation of locus coeruleus in breathing control in female rats.

    Science.gov (United States)

    de Carvalho, Débora; Patrone, Luis Gustavo A; Marques, Danuzia A; Vicente, Mariane C; Szawka, Raphael E; Anselmo-Franci, Janete A; Bícego, Kênia C; Gargaglioni, Luciane H

    2017-11-01

    Several evidences indicate that the locus coeruleus (LC) is involved in central chemoreception responding to CO 2 /pH and displaying a high percentage of chemosensitive neurons (>80%). However, there are no studies about the LC-mediated hypercapnic ventilation performed in females. Therefore, we assessed the role of noradrenergic LC neurons in non-ovariectomized (NOVX), ovariectomized (OVX) and estradiol (E2)-treated ovariectomized (OVX+E2) rats in respiratory response to hypercapnia, using a 6-hydroxydopamine (6-OHDA) - lesion model. A reduction in the number of tyrosine hydroxylase (TH) immunoreactive neurons (51-90% in 3 animals of NOVX group, 20-42% of lesion in 5 animals of NOVX females, 61.3% for OVX and 62.6% for OVX+E2 group) was observed seven days after microinjection of 6-OHDA in the LC. The chemical lesion of the LC resulted in decreased respiratory frequency under normocapnic conditions in OVX and OVX+E2 group. Hypercapnia increased ventilation in all groups as consequence of increases in respiratory frequency (fR) and tidal volume (V T ). Nevertheless, the hypercapnic ventilatory response was significantly decreased in 6-OHDA-NOVX>50% rats compared with SHAM-NOVX group and with females that had 20-42% of LC lesion. In OVX and OVX+E2 lesioned groups, no difference in CO 2 ventilatory response was observed when compared to SHAM-OVX and SHAM-OVX+E2 groups, respectively. Neither basal body temperature (Tb) nor Tb reduction in response to hypercapnia were affected by E2 treatment, ovariectomy or LC lesion. Thus, our data show that LC noradrenergic neurons seem to exert an excitatory role on the hypercapnic ventilatory response in female rats, as evidenced by the results in NOVX animals with LC lesioned more than 50%; however, this modulation is not observed in OVX and OVX+E2 rats. In addition, LC noradrenergic neurons of OVX females seem to provide a tonic excitatory drive to maintain breathing frequency in normocapnia, and this response may not to be

  8. Confirmatory factor analysis and invariance testing between Blacks and Whites of the Multidimensional Health Locus of Control scale.

    Science.gov (United States)

    LaNoue, Marianna; Harvey, Abby; Mautner, Dawn; Ku, Bon; Scott, Kevin

    2015-07-01

    The factor structure of the Multidimensional Health Locus of Control scale remains in question. Additionally, research on health belief differences between Black and White respondents suggests that the Multidimensional Health Locus of Control scale may not be invariant. We reviewed the literature regarding the latent variable structure of the Multidimensional Health Locus of Control scale, used confirmatory factor analysis to confirm the three-factor structure of the Multidimensional Health Locus of Control, and analyzed between-group differences in the Multidimensional Health Locus of Control structure and means across Black and White respondents. Our results indicate differences in means and structure, indicating more research is needed to inform decisions regarding whether and how to deploy the Multidimensional Health Locus of Control appropriately.

  9. The Impact of Locus of Control and Controlling Language on Psychological Reactance and Ad Effectiveness in Health Communication.

    Science.gov (United States)

    Xu, Jie

    2017-12-01

    Based on two theoretical models-psychological reactance theory (PRT) and locus of control-this study examines the individual and joint effects of locus of control and controlling language on young adults' information processing. Two experimental studies on anti-driving-after-drinking (anti-DAD) and antismoking public service announcements (PSAs) were conducted that were conceptual replications of each other. Both studies afforded evidence that those with external locus of control were more involved in risky behaviors. There was a consistent interaction between locus of control and controlling language, such that those with internal locus of control were more sensitive to this message feature compared to those with external locus of control. Controlling language was found to increase reactance. The theoretical and managerial implications for health communication are elaborated. Limitations and directions for future research are also outlined.

  10. The influence of U-2 fraction of a tortoise spleen extract on the formation of ectopic locus of haemopoiesis

    International Nuclear Information System (INIS)

    Turdyev, A.A.; Prus, E.K.; Basova, A.R.

    1990-01-01

    The implantation of a bone marrow fragment of intact mouse donors below the kidney capsule of irradiated (7 Gy) recipients leads to the formation of the haemopoiesis locus that somewhat exceeds, by mass and cellularity, the new-formed locus of control animals. The U-2 fraction of a tortoise spleen extract administered to recipients irradiated with the same dose increases the mass and cellularity of the haemopoiesis locus by 2.2 and 4.9 times respectively

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

    Science.gov (United States)

    Blair, Matthew W; Prieto, Sergio; Díaz, Lucy M; Buendía, Héctor F; Cardona, César

    2010-04-29

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

  12. Composición del locus de control en dos ciudades latinoamericanas

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    Jesús Francisco Laborín Álvarez

    2008-01-01

    Full Text Available El locus de control es un rasgo de personalidad vinculado con la atribución que hacen los individuos acerca de sus éxitos y fracasos. Los estudios en diferentes naciones y sociedades han demostrado que existen características generales y particulares respecto a la percepción de control y donde la cultura juega un papel importante. Se partió del objetivo de conocer la composición factorial del locus de control en dos poblaciones, Hermosillo, Sonora (México (n=600 y João Pessoa, Paraíba (Brasil (n=600; y establecer las diferencias en cuanto a dicho constructo en ambas poblaciones con respecto a las variables atributivas: edad, escolaridad, ocupación y ciudad. Los resultados revelan tres dimensiones comunes a las dos poblaciones: locus de control interno, locus de control afiliativo y locus de control externo. Los datos en general hacen ver que las muestras poblacionales de las ciudades hacen juicios de control en relación a los esfuerzos y el trabajo personal, en la afiliación a colectivos y grupos de interés como los fundamentos de explicación para éxitos y fracasos.

  13. Locus specificity in the mutability of mouse lymphoma strain LY-S

    International Nuclear Information System (INIS)

    Evans, H.H.; Mencl, J.; Horng, M.F.

    1985-01-01

    Mouse lymphoma L5178Y strains, LY-R and LY-S, are closely related but differ in their sensitivity to the lethal effects of radiation and various chemicals. Strain LY-S was originally isolated in 1961 following a spontaneous change in the sensitivity of cultured LY-R cells to ionizing radiation. The authors previously reported that, although strain LY-S is more sensitive to the lethal effects of ionizing radiation and alkylating agents than strain LY-R, it is markedly less mutable than strain LY-R at the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) locus. The isolated sublines of strains LY-R and LY-S which are heterozygous at the thymidine kinase (TK) locus. The LY-S TK+/- heterozygote, like its TK+/+ parent, is more sensitive to the lethal effects of ionizing radiation and alkylating agents and less mutable at the HGPRT locus by these agents than the LY-R TK+/- heterozygote. However, the LY-S heterozygote is 100 times more mutable by these agents at the TK locus than at the HGRT locus. In contrast to LY-R, the majority of the spontaneous and induced LY-S TK-/- mutants form small colonies in the presence of trifluorothymidine, indicating that in the LY-S heterozygote, the inactivation of the TK gene is accompanied by damage to, or rearrangement of neighboring genes

  14. Chronically ill patients’ expectations of therapeutic education and their health locus of control

    Directory of Open Access Journals (Sweden)

    Małgorzata Anna Basińska

    2015-12-01

    Full Text Available Background Beliefs as cognitive components of personality indicate what we consider as true or false and help us to answer questions concerning others, the world surrounding us and situations that we encounter. Beliefs about the health locus of control and their relations with expectations pertaining to therapeutic education seem to be of vital importance in the case of occurrence of a chronic illness. The aim of this paper is to verify whether expectations concerning therapeutic education in chronically ill patients demonstrate a relation with beliefs about the health locus of control and whether they vary according to gender, age and health, and to present the results of research that applies the Polish OE-15 scale for the evaluation of therapeutic education expectations depending on the health condition. Participants and procedure Two hundred and ninety-one persons were examined, including 180 patients and 111 healthy controls (the control group, 187 women and 104 men. The average age of subjects was 45.71 (SD = 13.51 years, ranging from 21 to 80 years. The OE-15 Therapeutic Education Expectations Scale and the Multidimensional Health Locus of Control Scale in versions relevant for patients and healthy controls as well as demographics were used. Results Age, gender and beliefs about the health locus of control are related to expectations of therapeutic education. Conclusions When providing therapeutic education for chronically ill patients, one should assess their expectations and pay attention to patients’ beliefs about the health locus of control.

  15. Oscillating Evolution of a Mammalian Locus with Overlapping Reading Frames: An XLalphas/ALEX Relay.

    Directory of Open Access Journals (Sweden)

    2005-08-01

    Full Text Available XLalphas and ALEX are structurally unrelated mammalian proteins translated from alternative overlapping reading frames of a single transcript. Not only are they encoded by the same locus, but a specific XLalphas/ALEX interaction is essential for G-protein signaling in neuroendocrine cells. A disruption of this interaction leads to abnormal human phenotypes, including mental retardation and growth deficiency. The region of overlap between the two reading frames evolves at a remarkable speed: the divergence between human and mouse ALEX polypeptides makes them virtually unalignable. To trace the evolution of this puzzling locus, we sequenced it in apes, Old World monkeys, and a New World monkey. We show that the overlap between the two reading frames and the physical interaction between the two proteins force the locus to evolve in an unprecedented way. Namely, to maintain two overlapping protein-coding regions the locus is forced to have high GC content, which significantly elevates its intrinsic evolutionary rate. However, the two encoded proteins cannot afford to change too quickly relative to each other as this may impair their interaction and lead to severe physiological consequences. As a result XLalphas and ALEX evolve in an oscillating fashion constantly balancing the rates of amino acid replacements. This is the first example of a rapidly evolving locus encoding interacting proteins via overlapping reading frames, with a possible link to the origin of species-specific neurological differences.

  16. [Locus of control and self-concept in interpersonal conflict resolution approaches].

    Science.gov (United States)

    Hisli Sahin, Nesrin; Basim, H Nejat; Cetin, Fatih

    2009-01-01

    The purpose of this study was to investigate the relationship between self-concept and locus of control in interpersonal conflict resolution approaches and to determine the predictors of conflict resolution approach choices. The study included 345 students aged between 18 and 28 years that were studying at universities in Ankara. Data were collected using the Interpersonal Conflict Resolution Approaches Scale to measure conflict resolution approaches, the Social Comparison Scale to measure self-concept, and the Internal-External Locus of Control Scale to measure locus of control. It was observed that confrontation approach to interpersonal conflict was predicted by self-concept (beta = 0.396, P resolution approaches. In addition to these findings, it was observed that females used self-disclosure (beta = -0.163, P resolution processes. Self-concept and locus of control were related to the behaviors adopted in the interpersonal conflict resolution process. Individuals with a positive self-concept and an internal locus of control adopted solutions to interpersonal conflict resolution that were more effective and constructive.

  17. Comparing Locus of Control, Assertiveness and General Health among Young Drug Addicts in Iran

    Directory of Open Access Journals (Sweden)

    Shahriar Shahidi

    2009-04-01

    Full Text Available "n "nObjective:The aim of this research was to compare the characteristics of assertiveness, locus of control and general health among young drug dependent patients in Iran. "n "nMethods: Three groups of Iranians: were choosed. The first group included drug dependent patients who had volunteered for treatment and had registered in the local Welfare Organization; the second group included dependent patients who were in the prison; and the third group held nondependent patients. All the participants were male and were matched for age and educational level . The following instruments were used in the present study: locus of control  uestionnaire , Assertiveness Scale and the General Health Questionnaire, GHQ. "n "nResults: The results of the present research showed that there were significant differences among the three groups in ssertiveness, locus of control and GHQ scores. It was found that participants in the non addictive group were more assertive and more internal in their locus of control and had higher GHQ scores than the other two groups. The participants in the prison group reported less assertiveness and lower GHQ scores than the non addictive group ; and their locus of control was more external. Conclusion: "n The results this study may be useful in terms of possible strategies for changing an attributive style in young adults in the framework of psychotherapy

  18. LocusTrack: Integrated visualization of GWAS results and genomic annotation.

    Science.gov (United States)

    Cuellar-Partida, Gabriel; Renteria, Miguel E; MacGregor, Stuart

    2015-01-01

    Genome-wide association studies (GWAS) are an important tool for the mapping of complex traits and diseases. Visual inspection of genomic annotations may be used to generate insights into the biological mechanisms underlying GWAS-identified loci. We developed LocusTrack, a web-based application that annotates and creates plots of regional GWAS results and incorporates user-specified tracks that display annotations such as linkage disequilibrium (LD), phylogenetic conservation, chromatin state, and other genomic and regulatory elements. Currently, LocusTrack can integrate annotation tracks from the UCSC genome-browser as well as from any tracks provided by the user. LocusTrack is an easy-to-use application and can be accessed at the following URL: http://gump.qimr.edu.au/general/gabrieC/LocusTrack/. Users can upload and manage GWAS results and select from and/or provide annotation tracks using simple and intuitive menus. LocusTrack scripts and associated data can be downloaded from the website and run locally.

  19. Does cognitive training improve internal locus of control among older adults?

    Science.gov (United States)

    Wolinsky, Fredric D; Vander Weg, Mark W; Martin, René; Unverzagt, Frederick W; Willis, Sherry L; Marsiske, Michael; Rebok, George W; Morris, John N; Ball, Karlene K; Tennstedt, Sharon L

    2010-09-01

    We evaluated the effect of cognitive training among 1,534 participants in the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) randomized controlled trial (RCT) on 5-year improvements in 3 cognitive-specific measures of locus of control-internal, chance, and powerful others. ACTIVE was a multisite RCT (age > or = 65), with 4 groups (memory, reasoning, speed of processing, and no-contact control). Complete 5-year follow-up data were available for 1,534 (55%) of the 2,802 participants. A propensity score model was used to adjust for potential attrition bias. Clinically important improvements (and decrements) in the cognitive-specific locus of control scale scores were defined as greater than or equal to 0.5 SD (medium) and greater than or equal to 1.0 SD (large). Multinomial logistic regression was used to simultaneously contrast those who improved and those who declined with those whose locus of control scale score was unchanged. Statistically significant effects reflecting medium-sized (> or = 0.5 SD) improvements in internal locus of control between baseline and the 5-year follow-up were found for the reasoning and speed of processing intervention groups who were 76% (p control group. No improvement effects were found on the chance or powerful others locus of control measures or for the memory intervention group. Cognitive training that targets reasoning and speed of processing can improve the cognitive-specific sense of personal control over one's life in older adults.

  20. Root locus analysis and design of the adaptation process in active noise control.

    Science.gov (United States)

    Tabatabaei Ardekani, Iman; Abdulla, Waleed H

    2012-10-01

    This paper applies root locus theory to develop a graphical tool for the analysis and design of adaptive active noise control systems. It is shown that the poles of the adaptation process performed in these systems move on typical trajectories in the z-plane as the adaptation step-size varies. Based on this finding, the dominant root of the adaptation process and its trajectory can be determined. The first contribution of this paper is formulating parameters of the adaptation process root locus. The next contribution is introducing a mechanism for modifying the trajectory of the dominant root in the root locus. This mechanism creates a single open loop zero in the original root locus. It is shown that appropriate localization of this zero can cause the dominant root of the locus to be pushed toward the origin, and thereby the adaptation process becomes faster. The validity of the theoretical findings is confirmed in an experimental setup which is implemented using real-time multi-threading and multi-core processing techniques.

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

    Science.gov (United States)

    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. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

  2. PENGARUH TEKANAN ANGGARAN WAKTU, LOCUS OF CONTROL DAN KOMITMEN PROFESIONAL PADA PERILAKU PENURUNAN KUALITAS AUDIT

    Directory of Open Access Journals (Sweden)

    NI Wayan Wiwin Intan Wintari

    2016-02-01

    Full Text Available The Impact of Time Budget Pressure, Locus of Control and Professional Commitment on the Reduction of Audit Quality Behavior. Reduced audit quality behavior is a serious threat to the auditing profession. Auditing cases, such as Enron Corporation and Worldcom have made the audit rofession to be the public spotlight, which makes the credibility of the auditors increasingly questionable. This study aimed to examine the factors that can cause reduced audit quality behavior such as time budget pressure, locus of control and professional commitment.  The research used questionnaire that was distributed to 70 auditors of BPKP Representative of Bali Province. Method of determining the sample was saturated sampling. The data analysis was conducted by multiple linear regressions, and the results showed that the time budget pressure and external locus of control has a positive influence on reduced audit quality behavior, while internal locus of control and professional commitment have negative effect.   Keywords:  reduced audit quality behavior, time budget pressure, locus of control, professional commitment

  3. Regulated expression of genes inserted at the human chromosomal β-globin locus by homologous recombination

    International Nuclear Information System (INIS)

    Nandi, A.K.; Roginski, R.S.; Gregg, R.G.; Smithies, O.; Skoultchi, A.I.

    1988-01-01

    The authors have examined the effect of the site of integration on the expression of cloned genes introduced into cultured erythroid cells. Smithies et al. reported the targeted integration of DNA into the human β-globin locus on chromosome 11 in a mouse erythroleukemia-human cell hybrid. These hybrid cells can undergo erythroid differentiation leading to greatly increased mouse and human β-globin synthesis. By transfection of these hybrid cells with a plasmid carrying a modified human β-globin gene and a foreign gene composed of the coding sequence of the bacterial neomycin-resistance gene linked to simian virus 40 transcription signals (SVneo), cells were obtained in which the two genes are integrated at the β-globin locus on human chromosome 11 or at random sites. When they examined the response of the integrated genes to cell differentation, they found that the genes inserted at the β-globin locus were induced during differentiation, whereas randomly positioned copies were not induced. Even the foreign SVneo gene was inducible when it had been integrated at the β-globin locus. The results show that genes introduced at the β-globin locus acquire some of the regulatory properties of globin genes during erythroid differentiation

  4. Identification of a novel locus for a USH3 like syndrome combined with congenital cataract

    DEFF Research Database (Denmark)

    Dad, S.; Østergaard, Elsebet; Thykjær, T.

    2010-01-01

    Usher syndrome (USH) is the most common genetic disease that causes both deafness and blindness. USH is divided into three types, USH1, USH2 and USH3, depending on the age of onset, the course of the disease, and on the degree of vestibular dysfunction. By homozygosity mapping of a consanguineous...... Danish family of Dutch descent, we have identified a novel locus for a rare USH3-like syndrome. The affected family members have a unique association of retinitis pigmentosa, progressive hearing impairment, vestibular dysfunction, and congenital cataract. The phenotype is similar, but not identical...... to that of USH3 patients, as congenital cataract has not been reported for USH3. By homozygosity mapping, we identified a 7.3 Mb locus on chromosome 15q22.2-23 with a maximum multipoint LOD score of 2.0. The locus partially overlaps with the USH1 locus, USH1H, a novel unnamed USH2 locus, and the non-syndromic...

  5. Relationships between Locus of Control, Self-Efficacy, Efforts and Academic Achievement among Engineering Students

    Directory of Open Access Journals (Sweden)

    Alias Maizam

    2016-01-01

    Full Text Available The aim of this study is to investigate the relationships between the affective learning needs namely, self-efficacy and locus of control, learning efforts and academic achievement among engineering students. For this purpose, a survey was conducted on first year engineering students from two technical universities in Malaysia. Self-efficacy and locus of control were assessed using existing instruments while learning efforts were assessed using a specifically designed instrument based on Carbonaro’s model of learning effort. Academic achievement data were based on cumulative grade point average (CGPA obtained from self-report by participants. The findings indicate that females engineering students tend to have higher self-efficacy compared to males while both groups have similar locus of control and invest in similar learning efforts. Only locus of control is found to be related to academic achievement while self-efficacy is found to be related to efforts. In conclusion, locus of control seems to be an important factor in predicting academic achievement among engineering students.

  6. Physical Localization of a Locus from Agropyron cristatum Conferring Resistance to Stripe Rust in Common Wheat.

    Science.gov (United States)

    Zhang, Zhi; Song, Liqiang; Han, Haiming; Zhou, Shenghui; Zhang, Jinpeng; Yang, Xinming; Li, Xiuquan; Liu, Weihua; Li, Lihui

    2017-11-13

    Stripe rust, caused by Puccinia striiformis f. sp. tritici ( Pst ), is one of the most destructive diseases of wheat ( Triticum aestivum L.) worldwide. Agropyron cristatum (L.) Gaertn. (2 n = 28, PPPP), one of the wild relatives of wheat, exhibits resistance to stripe rust. In this study, wheat- A . cristatum 6P disomic addition line 4844-12 also exhibited resistance to stripe rust. To identify the stripe rust resistance locus from A . cristatum 6P, ten translocation lines, five deletion lines and the BC₂F₂ and BC₃F₂ populations of two wheat- A . cristatum 6P whole-arm translocation lines were tested with a mixture of two races of Pst in two sites during 2015-2016 and 2016-2017, being genotyped with genomic in situ hybridization (GISH) and molecular markers. The result indicated that the locus conferring stripe rust resistance was located on the terminal 20% of 6P short arm's length. Twenty-nine 6P-specific sequence-tagged-site (STS) markers mapped on the resistance locus have been acquired, which will be helpful for the fine mapping of the stripe rust resistance locus. The stripe rust-resistant translocation lines were found to carry some favorable agronomic traits, which could facilitate their use in wheat improvement. Collectively, the stripe rust resistance locus from A . cristatum 6P could be a novel resistance source and the screened stripe rust-resistant materials will be valuable for wheat disease breeding.

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

    Science.gov (United States)

    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. An unusual occurrence of repeated single allele variation on Y-STR locus DYS458

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    Pankaj Shrivastava

    2016-09-01

    Full Text Available Six brothers were accused of gagging and raping a woman. A single male Y-STR profile was obtained from vaginal smear swab and clothes of the victim, which did not match with the DNA profile of the accused brothers. As a reference point, the blood sample of their father (aged 87 years was also analyzed with the same kit. The Y-STR haplotype of all six brothers was found to be the same as that of their father except at locus DYS458. At this locus, while the eldest, second and fourth siblings share allele 18 with their father, a loss of one repeat (allele 17 instead of 18 is observed in the third son while fifth and sixth siblings have allele 19 representing a gain of one repeat. Thus, two changes viz. a gain (twice and loss of one repeat at this locus in one generation is both interesting and unusual.

  9. Dissection of a locus on mouse chromosome 5 reveals arthritis promoting and inhibitory genes

    DEFF Research Database (Denmark)

    Lindvall, Therese; Karlsson, Jenny; Holmdahl, Rikard

    2009-01-01

    with Eae39 congenic- and sub-interval congenic mice, carrying RIIIS/J genes on the B10.RIII genetic background, revealed three loci within Eae39 that control disease and anti-collagen antibody titers. Two of the loci promoted disease and the third locus was protecting from collagen induced arthritis...... development. By further breeding of mice with small congenic fragments, we identified a 3.2 Megabasepair (Mbp) interval that regulates disease. CONCLUSIONS: Disease promoting- and protecting genes within the Eae39 locus on mouse chromosome 5, control susceptibility to collagen induced arthritis. A disease......-protecting locus in the telomeric part of Eae39 results in lower anti-collagen antibody responses. The study shows the importance of breeding sub-congenic mouse strains to reveal genetic effects on complex diseases....

  10. Note on guilt appeals in advertising: covariate effects of self-esteem and locus of control.

    Science.gov (United States)

    Pinto, M B; Worobetz, N D

    1992-02-01

    A 1991 study by Pinto and Priest demonstrated the effectiveness of advertisements employing moderate levels of guilt in inducing guilt responses in subjects. Because individuals' responses to guilt are often influenced by their specific personality characteristics, researchers have pointed to the potential moderating effects of individual difference variables such as level of self-esteem and locus of control on individuals' susceptibility to guilt appeals. A study was conducted to evaluate the possibility that self-esteem and locus of control can act as covariates across three treatment levels of guilt advertising. From a sample of 57 working mothers, advertisements stimulating medium and high levels of guilt elicited significantly greater feelings of guilt in subjects than the control advertisement stimulating low guilt. However, the relationship between susceptibility to guilt appeals and self-esteem and locus of control was not observed to covary.

  11. Jurors' locus of control and defendants' attractiveness in death penalty sentencing.

    Science.gov (United States)

    Beckham, Crystal M; Spray, Beverly J; Pietz, Christina A

    2007-06-01

    The authors examined the relationship between jurors' locus of control and defendants' attractiveness in death penalty sentencing. Ninety-eight participants voluntarily served as mock jurors. The authors administered J. B. Rotter's (1966) Internal-External Locus of Control Scale to participants and then randomly assigned them to a group with either an attractive or an unattractive defendant (represented by photographs). Participants read a murder vignette and selected a punishment--either a lifetime jail sentence or the death penalty-for the defendant. Results indicated that neither jurors' locus of control nor defendants' attractiveness influenced sentencing. However, jurors' age and gender significantly influenced sentencing. Men, with the exception of the youngest men, were more likely than women to choose the death penalty. Additionally, young women were more likely than older women to select the death penalty. The authors discuss the implications of these results for the study of jury behavior and bias.

  12. The Limits of the Use of Locus of Control in Industrial Psychology: A Critical Evaluation

    Directory of Open Access Journals (Sweden)

    Emir Üzümçeker

    2016-10-01

    Full Text Available Locus of control is a personality variable that is employed by researchers from diverse disciplines. This article examines the limits of the construct’s usage in industrial and organizational psychology. Although locus of control is documented to predict a wide array of workplace behavior such as job satisfaction, job performance and turnover intention, some important conceptual, methodological and empirical flaws raise suspicions on the explanations proposed by researchers. Considering the shortage of experimental and longitudinal evidence, it is argued that the causal direction of the well-established correlations between locus of control and other organizational behavioral variables might be the opposite of the theory’s expectation. It is also claimed that some related constructs such as self-efficacy and belief in a just world might provide further explanations for observed correlations.

  13. Insertions in the OCL1 locus of Acinetobacter baumannii lead to shortened lipooligosaccharides

    Science.gov (United States)

    Kenyon, Johanna J.; Holt, Kathryn E.; Pickard, Derek; Dougan, Gordon; Hall, Ruth M.

    2014-01-01

    Genomes of 82 Acinetobacter baumannii global clones 1 (GC1) and 2 (GC2) isolates were sequenced and different forms of the locus predicted to direct synthesis of the outer core (OC) of the lipooligosaccharide were identified. OCL1 was in all GC2 genomes, whereas GC1 isolates carried OCL1, OCL3 or a new locus, OCL5. Three mutants in which an insertion sequence (ISAba1 or ISAba23) interrupted OCL1 were identified. Isolates with OCL1 intact produced only lipooligosaccharide, while the mutants produced lipooligosaccharide of reduced molecular weight. Thus, the assignment of the OC locus as that responsible for the synthesis of the OC is correct. PMID:24861001

  14. Association of Posttraumatic Stress Disorder With Reduced In Vivo Norepinephrine Availability in the Locus Coeruleus

    Science.gov (United States)

    Pietrzak, Robert H.; Gallezot, Jean-Dominique; Ding, Yu-Shin; Henry, Shannan; Potenza, Marc N.; Southwick, Steven M.; Krystal, John H.; Carson, Richard E.; Neumeister, Alexander

    2014-01-01

    IMPORTANCE Animal data suggest that chronic stress is associated with a reduction in norepinephrine transporter (NET) availability in the locus coeruleus. However, it is unclear whether such models are relevant to posttraumatic stress disorder (PTSD), which has been linked to noradrenergic dysfunction in humans. OBJECTIVES To use positron emission tomography and the radioligand [11C]methylreboxetine to examine in vivo NET availability in the locus coeruleus in the following 3 groups of individuals: healthy adults (HC group), adults exposed to trauma who did not develop PTSD (TC group), and adults exposed to trauma who developed PTSD (PTSD group) and to evaluate the relationship between NET availability in the locus coeruleus and a contemporary phenotypic model of PTSD symptoms. DESIGN, SETTING, AND PARTICIPANTS Cross-sectional positron emission tomography study under resting conditions at academic and Veterans Affairs medical centers among 56 individuals in the following 3 study groups: HC (n = 18), TC (n = 16), and PTSD (n = 22). MAIN OUTCOMES AND MEASURES The [11C]methylreboxetine-binding potential of NET availability in the locus coeruleus and the severity of PTSD symptoms assessed using the Clinician-Administered PTSD Scale. RESULTS The PTSD group had significantly lower NET availability than the HC group (41% lower, Cohen d = 1.07). NET availability did not differ significantly between the TC and HC groups (31% difference, Cohen d = 0.79) or between the TC and PTSD groups (15% difference, Cohen d = 0.28). In the PTSD group, NET availability in the locus coeruleus was independently positively associated with the severity of anxious arousal (ie, hypervigilance) symptoms (r = 0.52) but not with any of the other PTSD symptom clusters. CONCLUSIONS AND RELEVANCE These results suggest that PTSD is associated with significantly reduced NET availability in the locus coeruleus and that greater NET availability in this brain region is associated with increased severity

  15. Locus of Control and Career Interest of Sophomore Accountancy Students: Basis for Employment Path

    Directory of Open Access Journals (Sweden)

    Jovielyn Mañibo

    2014-02-01

    Full Text Available This academic undertaking sought to determine the relationship between the locus of control and career interest of the respondents towards their future employment. The objectives of the study were to determine the respondents’ locus of control and career interest; to find if there is a significant relationship between the respondents’ locus of control and career interest and to develop an action plan that will gauge the students’ employment success as to their chosen field. In measuring and finding the relationship between the variables of the study, the researchers employed the quantitative method in the analysis of data using the questionnaires for locus of control (LOC and Career Cluster Interest Survey (CCIS as dominant tools. The participants chosen from this study were 74sophomore Accountancy students for Second Semester, School Year 2012 – 2013. Based from the results, most of the respondents (74 sophomore accountancy students have an external locus of control with career interest on education and training, human services, and finance. The computed rvalues indicates slight positive correlation, however, careers on government services, manufacturing , public administration, health science, human services showed significant correlation to internal (positive and external (negative locus of control. .Likewise, the Counseling and Testing Center of the university should conduct cognitive training targeting reasoning and speed of processing that can improve sense of personal control over one’s life and facilitate career orientation during the student- applicants’ admission as regards to their National Career Assessment Examination (NCAE results. With the findings of the study, a program design was created to gauge students employment path.

  16. Locus of control among spinal cord injury patients with different levels of posttraumatic stress disorder.

    Science.gov (United States)

    Chung, Man Cheung; Preveza, Eleni; Papandreou, Konstantinos; Prevezas, Nikolaos

    2007-08-30

    Two hypotheses were investigated in the present study: 1) Patients with full posttraumatic stress symptoms following spinal cord injury (SCI) would experience more general health problems than those with partial posttraumatic stress disorder (PTSD), with no-PTSD and the control group; 2) Patients with full PTSD would endorse the external locus of control more than those with partial PTSD, no-PTSD and the control group. Sixty-two patients were recruited from a specialized rehabilitation clinic for spinal cord injury. The control group comprised 60 participants without SCI. Patients with SCI were assessed using the Posttraumatic Stress Disorder Checklist, the General Health Questionnaire-28 (GHQ-28) and the Multidimensional Health Locus of Control (MHLC). The control group was assessed using the GHQ-28 and the MHLC. The full PTSD group experienced more somatic problems, anxiety, social dysfunction and depression than the partial PTSD, the no-PTSD and the control groups. The results also showed that the full PTSD group endorsed significantly more external health locus of control than the control group. However, no significant differences were found between the three patient groups in health locus of control. The three PTSD sub-scales were positively correlated with general health problems. Further analyses showed that partial PTSD patients with paraplegia and partial PTSD patients whose SCI had a medically related cause were more likely to report less internal locus of control than other patients. Patients who suffered from full PTSD experienced more general health problems than those with fewer PTSD symptoms and those without SCI. External locus of control was a distinctive strategy that SCI-PTSD patients used in coping with the effects of SCI-PTSD.

  17. Characterization of histone H3K27 modifications in the β-globin locus

    International Nuclear Information System (INIS)

    Kim, Yea Woon; Kim, AeRi

    2011-01-01

    Research highlights: → The β-globin locus control region is hyperacetylated and monomethylated at histone H3K27. → Highly transcribed globin genes are marked by H3K27ac, but H3K27me2 is remarkable at silent globin genes in erythroid K562 cells. → Association of PRC2 subunits is comparable with H3K27me3 pattern. → Modifications of histone H3K27 are established in an enhancer-dependent manner. -- Abstract: Histone H3K27 is acetylated or methylated in the environment of nuclear chromatin. Here, to characterize the modification pattern of H3K27 in locus control region (LCR) and to understand the correlation of various H3K27 modifications with transcriptional activity of genes, we analyzed the human β-globin locus using the ChIP assay. The LCR of the human β-globin locus was enriched by H3K27ac and H3K27me1 in erythroid K562 cells. The highly transcribed globin genes were hyperacetylated at H3K27, but the repressed globin genes were highly dimethylated at this lysine in these cells. However, in non-erythroid 293FT cells, the β-globin locus was marked by a high level of H3K27me3. EZH2 and SUZ12, subunits of polycomb repressive complex 2, were comparably detected with the H3K27me3 pattern in K562 and 293FT cells. In addition, H3K27ac, H3K27me1 and H3K27me3 were established in an enhancer-dependent manner in a model minichromosomal locus containing an enhancer and its target gene. Taken together, these results show that H3K27 modifications have distinctive correlations with the chromatin state or transcription level of genes and are influenced by an enhancer.

  18. Single locus affects embryonic segment polarity and multiple aspects of an adult evolutionary novelty

    Directory of Open Access Journals (Sweden)

    Saenko Suzanne V

    2010-08-01

    Full Text Available Abstract Background The characterization of the molecular changes that underlie the origin and diversification of morphological novelties is a key challenge in evolutionary developmental biology. The evolution of such traits is thought to rely largely on co-option of a toolkit of conserved developmental genes that typically perform multiple functions. Mutations that affect both a universal developmental process and the formation of a novelty might shed light onto the genetics of traits not represented in model systems. Here we describe three pleiotropic mutations with large effects on a novel trait, butterfly eyespots, and on a conserved stage of embryogenesis, segment polarity. Results We show that three mutations affecting eyespot size and/or colour composition in Bicyclus anynana butterflies occurred in the same locus, and that two of them are embryonic recessive lethal. Using surgical manipulations and analysis of gene expression patterns in developing wings, we demonstrate that the effects on eyespot morphology are due to changes in the epidermal response component of eyespot induction. Our analysis of morphology and of gene expression in mutant embryos shows that they have a typical segment polarity phenotype, consistent with the mutant locus encoding a negative regulator of Wingless signalling. Conclusions This study characterizes the segregation and developmental effects of alleles at a single locus that controls the morphology of a lineage-specific trait (butterfly eyespots and a conserved process (embryonic segment polarity and, specifically, the regulation of Wingless signalling. Because no gene with such function was found in the orthologous, highly syntenic genomic regions of two other lepidopterans, we hypothesize that our locus is a yet undescribed, possibly lineage-specific, negative regulator of the conserved Wnt/Wg pathway. Moreover, the fact that this locus interferes with multiple aspects of eyespot morphology and maps to a

  19. An unusual occurrence of repeated single allele variation on Y-STR locus DYS458

    OpenAIRE

    Shrivastava, Pankaj; Trivedi, Veena Ben; Jain, Toshi; Ali, Mehmood

    2016-01-01

    Six brothers were accused of gagging and raping a woman. A single male Y-STR profile was obtained from vaginal smear swab and clothes of the victim, which did not match with the DNA profile of the accused brothers. As a reference point, the blood sample of their father (aged 87 years) was also analyzed with the same kit. The Y-STR haplotype of all six brothers was found to be the same as that of their father except at locus DYS458. At this locus, while the eldest, second and fourth siblings s...

  20. Age differences in coping and locus of control: a study of managerial stress in Hong Kong.

    Science.gov (United States)

    Siu, O; Cooper, C L; Spector, P E; Donald, I

    2001-12-01

    The present study involved data collection from 3 samples of Hong Kong managers to examine mechanisms by which age would relate to work well-being. A total of 634 managers was drawn by random sampling and purposive sampling methods. The results showed that age was positively related to well-being (job satisfaction and mental well-being). Furthermore, older managers reported fewer sources of stress, better coping, and a more internal locus of control. Multiple regression analyses suggested that the relations of age with 2 well-being indicators can be attributed to various combinations of coping, work locus of control, sources of stress, managerial level, and organizational tenure.

  1. Self-statements, locus of control, and depression in predicting self-esteem.

    Science.gov (United States)

    Philpot, V D; Holliman, W B; Madonna, S

    1995-06-01

    The contributions of frequency of positive and negative self-statements and their ratio, locus of control, and depression in prediction of self-esteem were examined. Volunteers were 145 college students (100 women and 45 men) who were administered the Coopersmith Self-esteem Inventory-Adult Form, Automatic Thought Questionnaire-Revised, the Beck Depression Inventory, and the Rotter Internal-External Locus of Control Scale. Intercorrelations suggested significant relationships among variables. The magnitude of the relationship was strongest between the frequency of negative self-statements and self-esteem. These results are consistent with and lend further support to prior studies of Kendall, et al. and Schwartz and Michaelson.

  2. Updated listing of haplotypes at the human phenylalanine hydroxylase (PAH) locus

    Energy Technology Data Exchange (ETDEWEB)

    Eisensmith, R.C.; Woo, S.L.C. (Baylor College of Medicine, Houston, TX (United States))

    1992-12-01

    Analysis of mutant PAH chromosomes has identified approximately 60 different single-base substitutions and deletions within the PAH locus. Nearly all of these molecular lesions are in strong linkage disequilibrium with specific RFLP haplotypes in different ethnic populations. Thus, haplotype analysis is not only useful for diagnostic purposes but is proving to be a valuable tool in population genetic studies of the origin and spread of phenylketonuria alleles in human populations. PCR-based methods have been developed to detect six of the eight polymorphic restriction sites used for determination of RFLP haplotypes at the PAH locus. A table of the proposed expanded haplotypes is given.

  3. Antagonism between DNA and H3K27 methylation at the imprinted Rasgrf1 locus

    DEFF Research Database (Denmark)

    Lindroth, Anders M; Park, Yoon Jung; McLean, Chelsea M

    2008-01-01

    At the imprinted Rasgrf1 locus in mouse, a cis-acting sequence controls DNA methylation at a differentially methylated domain (DMD). While characterizing epigenetic marks over the DMD, we observed that DNA and H3K27 trimethylation are mutually exclusive, with DNA and H3K27 methylation limited...... to the paternal and maternal sequences, respectively. The mutual exclusion arises because one mark prevents placement of the other. We demonstrated this in five ways: using 5-azacytidine treatments and mutations at the endogenous locus that disrupt DNA methylation; using a transgenic model in which the maternal...

  4. Immotile cilia syndrome: A recombinant family at HLA-linked gene locus

    Energy Technology Data Exchange (ETDEWEB)

    Gasparini, P.; Grifa, A.; Oggiano, N.; Fabbrizzi, E.; Giorgi, P.L. [Univsita di Ancona (Israel)

    1994-02-15

    The immotile-cilia syndrome (ICS) is an autosomal recessive trait of congenital dismobility or even complete immobility of cilia in the ciliated epithelia (MIM 244400). Recurrent upper respiratory infections in early childhood are the most common clinical findings. Recently a disease locus was mapped by sib pair analysis in two unrelated families on 6p tightly linked to HLA class II loci, such as DR and DQ. In order to confirm this assignment and to test the presence of possible heterogeneity, the authors analyzed several ICS families utilizing DNA makers of HLA class II region. Here they report the identification of a recombinant family at this locus. 3 refs., 1 fig.

  5. Sensorineural hearing loss and Mondini dysplasia caused by a deletion at locus DFN3.

    Science.gov (United States)

    Arellano, B; Ramírez Camacho, R; García Berrocal, J R; Villamar, M; del Castillo, I; Moreno, F

    2000-09-01

    To study a family with inner ear malformations and sensorineural hearing loss. Clinical, radiological, and genetic study of the members of a family with different degrees of sensorineural hearing loss. The males in the family manifested profound congenital hearing loss with severe inner ear malformations, while the only affected female had progressive hearing loss that had begun during puberty. Computed tomography showed inner ear malformations in both males, with enlarged internal auditory meatus and Mondini dysplasia. Genetic analysis disclosed a microdeletion at the locus DFN3 on chromosome X. A familial Mondini dysplasia is associated to a microdeletion at the deafness locus DFN3.

  6. Diferencias individuales y desarrollo de habilidades de liderazgo : el rol del locus de control

    OpenAIRE

    García Hernández, Jorge Alejandro; Guarin Galvis, Stephany

    2015-01-01

    El presente proyecto se ha elaborado con la finalidad de encontrar la relación existente entre el liderazgo y el locus de control, por medio de una revisión documental que permita dar una visión más amplia de estos dos fenómenos. De acuerdo con investigaciones realizadas, existen características individuales que afectan el desarrollo de liderazgo, lo cual a su vez tiene un impacto sobre el comportamiento de los individuos dentro de una sociedad. Uno de estos factores es el locus de contro...

  7. PHIP – a novel candidate breast cancer susceptibility locus on 6q14.1

    OpenAIRE

    Jiao, X; Easton, Douglas Frederick

    2017-01-01

    Most non-BRCA1/2 breast cancer families have no identified genetic cause. We used linkage and haplotype analyses in familial and sporadic breast cancer cases to identify a susceptibility locus on chromosome 6q. Two independent genome-wide linkage analysis studies suggested a 3 Mb locus on chromosome 6q and two unrelated Swedish families with a LOD >2 together seemed to share a haplotype in 6q14.1. We hypothesized that this region harbored a rare high-risk founder allele contributing to breast...

  8. Nonlinkage of D6S260, a putative schizophrenia locus, to bipolar affective disorder

    Energy Technology Data Exchange (ETDEWEB)

    Adams, L.J.; Mitchell, P.B. [Univ. of South Wales (Australia); Salmon, J. [Garvan Institute of Medical Research, Sydney, New South Wales (Australia)] [and others

    1996-09-20

    To examine whether genes that predispose to schizophrenia also confer a predisposition to other psychiatric disorders such as bipolar affective disorder (BAD), we tested for linkage between the recently identified schizophrenia susceptibility locus D6S260 and the inheritance of BAD in 12 large Australian pedigrees. We found no evidence for linkage over a region of 12-27 cM from the D6S260 locus, depending on the model used. Our results therefore do not provide support for the continuum theory of psychosis. 13 refs., 2 tabs.

  9. Farsi version of the multidimensional health locus of control and God locus of health control scales: validity and reliability study among Iranian women with a family history of breast cancer.

    Science.gov (United States)

    Hashemian, Masoumeh; Aminshokravi, Farkhonde; Hidarnia, Alireza; Lamyian, Minoor; Hassanpour, Kazem; Akaberi, Arash; Moshki, Mahdi

    2014-09-01

    To determine the Persian version's reliability and validity of the Multidimensional Health Locus of Control and God Health Locus of Control scales among women with family history of breast cancer. The cross-sectional study was conducted in Sabzevar, Iran, in 2012. It randomly selected women with family members affected by breast cancer. Predesigned questionnaires were completed through interviews. Content and face validity was evaluated using the opinions of a panel of experts, and construct validity was confirmed by applying confirmatory factor analysis.The instruments' reliability was assessed using Cronbach's alpha and test-retest reliability. There were 200 women in the study with their age ranging between 18 and 69 years and revealed the following; root mean square error of approximation for Multidimensional Health Locus of Control Scale = 0.013, and God Locus of Health Control Scale = 0.077; comparative fit index = 0.999, 0.998; incremental fit index = 0.999, 0.998;Tucker-Lewis fit index = 0.998, 0.998; and normed fit index = 0.983, 0.997 respectively. Cronbach's alpha was 0.61 for Internal Health Locus of Control, 0.8 for Chance Health Locus of Control, 0.68 for Power Health Locus of Control and 0.9 for God Locus Health Control. The Persian version of the subscales supported the main version.

  10. Positive correlations between the health locus of control and self-management behaviors in hemodialysis patients in Xiamen

    Directory of Open Access Journals (Sweden)

    Jia-Li Fan

    2016-03-01

    Conclusion: The results of this study provided evidence that there is a strong relationship between the health locus of control and self-management behaviors in hemodialysis patients. This study provides important information for medical professionals as they design strategies to educate hemodialysis patients on their health locus of control and self-management behaviors.

  11. Integration of least angle regression with empirical Bayes for multi-locus genome-wide association studies

    Science.gov (United States)

    Multi-locus genome-wide association studies has become the state-of-the-art procedure to identify quantitative trait loci (QTL) associated with traits simultaneously. However, implementation of multi-locus model is still difficult. In this study, we integrated least angle regression with empirical B...

  12. Job Stress and Locus of Control in Teachers: Comparisons between Samples from the United States and Zimbabwe

    Science.gov (United States)

    Crothers, Laura M.; Kanyongo, Gibbs Y.; Kolbert, Jered B.; Lipinski, John; Kachmar, Steven P.; Koch, Gary D.

    2010-01-01

    This study examines the relationship between educators' locus of control and job stress using samples from the US and Zimbabwe. Multiple regression analyses are used to identify significant relationships in the US sample between teachers' external locus of control and the severity of the job stress that they experience, coupled with the perceived…

  13. Investigating Prospective Teachers' Perceived Problem-Solving Abilities in Relation to Gender, Major, Place Lived, and Locus of Control

    Science.gov (United States)

    Çakir, Mustafa

    2017-01-01

    The purpose of this study is to investigate prospective teachers' perceived personal problem-solving competencies in relation to gender, major, place lived, and internal-external locus of control. The Personal Problem-Solving Inventory and Rotter's Internal-External Locus of Control Scale were used to collect data from freshman teacher candidates…

  14. Locus of Control, Interest in Schooling and Science Achievement of Some Deaf and Typical Secondary School Students in Nigeria

    Science.gov (United States)

    Olatoye, R. Ademola; Aanu, E. Mosunmola

    2010-01-01

    This study compared locus of control, interest in school and science achievement of typical and deaf secondary school students. The study also investigated influence of students' locus of control and interest in school on general science achievement. Seventy two (72) deaf and 235 typical children were purposively selected from eight secondary…

  15. An Investigation of Preservice Teachers' Perceptions of Locus of Control, Self-Regulation, and Motivation in Online Learning

    Science.gov (United States)

    Min, Sung-Ho

    2012-01-01

    This study examined how students' perceptions of locus of control, self-regulation, and motivation were related in an online learning environment. The participants were 73 preservice teachers enrolled in two online technology courses. Near the end of their online course, the participants completed "Brown's Locus of Control…

  16. Multiple independent variants at the TERT locus are associated with telomere length and risks of breast and ovarian cancer

    NARCIS (Netherlands)

    Bojesen, Stig E.; Pooley, Karen A.; Johnatty, Sharon E.; Beesley, Jonathan; Michailidou, Kyriaki; Tyrer, Jonathan P.; Edwards, Stacey L.; Pickett, Hilda A.; Shen, Howard C.; Smart, Chanel E.; Hillman, Kristine M.; Mai, Phuong L.; Lawrenson, Kate; Stutz, Michael D.; Lu, Yi; Karevan, Rod; Woods, Nicholas; Johnston, Rebecca L.; French, Juliet D.; Chen, Xiaoqing; Weischer, Maren; Nielsen, Sune F.; Maranian, Melanie J.; Ghoussaini, Maya; Ahmed, Shahana; Baynes, Caroline; Bolla, Manjeet K.; Wang, Qin; Dennis, Joe; McGuffog, Lesley; Barrowdale, Daniel; Lee, Andrew; Healey, Sue; Lush, Michael; Tessier, Daniel C.; Vincent, Daniel; Bacot, Françis; Vergote, Ignace; Lambrechts, Sandrina; Despierre, Evelyn; Risch, Harvey A.; González-Neira, Anna; Rossing, Mary Anne; Pita, Guillermo; Doherty, Jennifer A.; Alvarez, Nuria; Larson, Melissa C.; Fridley, Brooke L.; Schoof, Nils; Chang-Claude, Jenny; Cicek, Mine S.; Peto, Julian; Kalli, Kimberly R.; Broeks, Annegien; Armasu, Sebastian M.; Schmidt, Marjanka K.; Braaf, Linde M.; Winterhoff, Boris; Nevanlinna, Heli; Konecny, Gottfried E.; Lambrechts, Diether; Rogmann, Lisa; Guénel, Pascal; Teoman, Attila; Milne, Roger L.; Garcia, Joaquin J.; Cox, Angela; Shridhar, Vijayalakshmi; Burwinkel, Barbara; Marme, Frederik; Hein, Rebecca; Sawyer, Elinor J.; Haiman, Christopher A.; Wang-Gohrke, Shan; Andrulis, Irene L.; Moysich, Kirsten B.; Hopper, John L.; Odunsi, Kunle; Lindblom, Annika; Giles, Graham G.; Brenner, Hermann; Simard, Jacques; Lurie, Galina; Fasching, Peter A.; Carney, Michael E.; Radice, Paolo; Wilkens, Lynne R.; Swerdlow, Anthony; Goodman, Marc T.; Brauch, Hiltrud; Garcia-Closas, Montserrat; Hillemanns, Peter; Winqvist, Robert; Dürst, Matthias; Devilee, Peter; Runnebaum, Ingo; Jakubowska, Anna; Lubinski, Jan; Mannermaa, Arto; Butzow, Ralf; Bogdanova, Natalia V.; Dörk, Thilo; Pelttari, Liisa M.; Zheng, Wei; Leminen, Arto; Anton-Culver, Hoda; Bunker, Clareann H.; Kristensen, Vessela; Ness, Roberta B.; Muir, Kenneth; Edwards, Robert; Meindl, Alfons; Heitz, Florian; Matsuo, Keitaro; du Bois, Andreas; Wu, Anna H.; Harter, Philipp; teo, Soo-Hwang; Schwaab, Ira; Shu, Xiao-Ou; Blot, William; Hosono, Satoyo; Kang, Daehee; Nakanishi, Toru; Hartman, Mikael; Yatabe, Yasushi; Hamann, Ute; Karlan, Beth Y.; Sangrajrang, Suleeporn; Kjaer, Susanne Krüger; Gaborieau, Valerie; Jensen, Allan; Eccles, Diana; Høgdall, Estrid; Shen, Chen-Yang; Brown, Judith; Woo, Yin Ling; Shah, Mitul; Azmi, Mat Adenan Noor; Luben, Robert; Omar, Siti Zawiah; Czene, Kamila; Vierkant, Robert A.; Nordestgaard, Børge G.; Flyger, Henrik; Vachon, Celine; Olson, Janet E.; Wang, Xianshu; Levine, Douglas A.; Rudolph, Anja; Weber, Rachel Palmieri; Flesch-Janys, Dieter; Iversen, Edwin; Nickels, Stefan; Schildkraut, Joellen M.; Silva, Isabel Dos Santos; Cramer, Daniel W.; Gibson, Lorna; Terry, Kathryn L.; Fletcher, Olivia; Vitonis, Allison F.; van der Schoot, C. Ellen; Poole, Elizabeth M.; Hogervorst, Frans B. L.; Tworoger, Shelley S.; Liu, Jianjun; Bandera, Elisa V.; Li, Jingmei; Olson, Sara H.; Humphreys, Keith; Orlow, Irene; Blomqvist, Carl; Rodriguez-Rodriguez, Lorna; Aittomäki, Kristiina; Salvesen, Helga B.; Muranen, Taru A.; Wik, Elisabeth; Brouwers, Barbara; Krakstad, Camilla; Wauters, Els; Halle, Mari K.; Wildiers, Hans; Kiemeney, Lambertus A.; Mulot, Claire; Aben, Katja K.; Laurent-Puig, Pierre; Altena, Anne Mvan; Truong, Thérèse; Massuger, Leon F. A. G.; Benitez, Javier; Pejovic, Tanja; Perez, Jose Ignacio Arias; Hoatlin, Maureen; Zamora, M. Pilar; Cook, Linda S.; Balasubramanian, Sabapathy P.; Kelemen, Linda E.; Schneeweiss, Andreas; Le, Nhu D.; Sohn, Christof; Brooks-Wilson, Angela; Tomlinson, Ian; Kerin, Michael J.; Miller, Nicola; Cybulski, Cezary; Henderson, Brian E.; Menkiszak, Janusz; Schumacher, Fredrick; Wentzensen, Nicolas; Le Marchand, Loic; Yang, Hannah P.; Mulligan, Anna Marie; Glendon, Gord; Engelholm, Svend Aage; Knight, Julia A.; Høgdall, Claus K.; Apicella, Carmel; Gore, Martin; Tsimiklis, Helen; Song, Honglin; Southey, Melissa C.; Jager, Agnes; den Ouweland, Ans M. Wvan; Brown, Robert; Martens, John W. M.; Flanagan, James M.; Kriege, Mieke; Paul, James; Margolin, Sara; Siddiqui, Nadeem; Severi, Gianluca; Whittemore, Alice S.; Baglietto, Laura; McGuire, Valerie; Stegmaier, Christa; Sieh, Weiva; Müller, Heiko; Arndt, Volker; Labrèche, France; Gao, Yu-Tang; Goldberg, Mark S.; Yang, Gong; Dumont, Martine; McLaughlin, John R.; Hartmann, Arndt; Ekici, Arif B.; Beckmann, Matthias W.; Phelan, Catherine M.; Lux, Michael P.; Permuth-Wey, Jenny; Peissel, Bernard; Sellers, Thomas A.; Ficarazzi, Filomena; Barile, Monica; Ziogas, Argyrios; Ashworth, Alan; Gentry-Maharaj, Aleksandra; Jones, Michael; Ramus, Susan J.; Orr, Nick; Menon, Usha; Pearce, Celeste L.; Brüning, Thomas; Pike, Malcolm C.; Ko, Yon-Dschun; Lissowska, Jolanta; Figueroa, Jonine; Kupryjanczyk, Jolanta; Chanock, Stephen J.; Dansonka-Mieszkowska, Agnieszka; Jukkola-Vuorinen, Arja; Rzepecka, Iwona K.; Pylkäs, Katri; Bidzinski, Mariusz; Kauppila, Saila; Hollestelle, Antoinette; Seynaeve, Caroline; Tollenaar, Rob A. E. M.; Durda, Katarzyna; Jaworska, Katarzyna; Hartikainen, Jaana M.; Kosma, Veli-Matti; Kataja, Vesa; Antonenkova, Natalia N.; Long, Jirong; Shrubsole, Martha; Deming-Halverson, Sandra; Lophatananon, Artitaya; Siriwanarangsan, Pornthep; Stewart-Brown, Sarah; Ditsch, Nina; Lichtner, Peter; Schmutzler, Rita K.; Ito, Hidemi; Iwata, Hiroji; Tajima, Kazuo; Tseng, Chiu-Chen; Stram, Daniel O.; van den Berg, David; Yip, Cheng Har; Ikram, M. Kamran; teh, Yew-Ching; Cai, Hui; Lu, Wei; Signorello, Lisa B.; Cai, Qiuyin; Noh, Dong-Young; Yoo, Keun-Young; Miao, Hui; Iau, Philip Tsau-Choong; teo, Yik Ying; McKay, James; Shapiro, Charles; Ademuyiwa, Foluso; Fountzilas, George; Hsiung, Chia-Ni; Yu, Jyh-Cherng; Hou, Ming-Feng; Healey, Catherine S.; Luccarini, Craig; Peock, Susan; Stoppa-Lyonnet, Dominique; Peterlongo, Paolo; Rebbeck, Timothy R.; Piedmonte, Marion; Singer, Christian F.; Friedman, Eitan; Thomassen, Mads; Offit, Kenneth; Hansen, Thomas V. O.; Neuhausen, Susan L.; Szabo, Csilla I.; Blanco, Ignacio; Garber, Judy; Narod, Steven A.; Weitzel, Jeffrey N.; Montagna, Marco; Olah, Edith; Godwin, Andrew K.; Yannoukakos, Drakoulis; Goldgar, David E.; Caldes, Trinidad; Imyanitov, Evgeny N.; Tihomirova, Laima; Arun, Banu K.; Campbell, Ian; Mensenkamp, Arjen R.; van Asperen, Christi J.; van Roozendaal, Kees E. P.; Meijers-Heijboer, Hanne; Collée, J. Margriet; Oosterwijk, Jan C.; Hooning, Maartje J.; Rookus, Matti A.; van der Luijt, Rob B.; Os, Theo A. Mvan; Evans, D. Gareth; Frost, Debra; Fineberg, Elena; Barwell, Julian; Walker, Lisa; Kennedy, M. John; Platte, Radka; Davidson, Rosemarie; Ellis, Steve D.; Cole, Trevor; Bressac-de Paillerets, Brigitte; Buecher, Bruno; Damiola, Francesca; Faivre, Laurence; Frenay, Marc; Sinilnikova, Olga M.; Caron, Olivier; Giraud, Sophie; Mazoyer, Sylvie; Bonadona, Valérie; Caux-Moncoutier, Virginie; Toloczko-Grabarek, Aleksandra; Gronwald, Jacek; Byrski, Tomasz; Spurdle, Amanda B.; Bonanni, Bernardo; Zaffaroni, Daniela; Giannini, Giuseppe; Bernard, Loris; Dolcetti, Riccardo; Manoukian, Siranoush; Arnold, Norbert; Engel, Christoph; Deissler, Helmut; Rhiem, Kerstin; Niederacher, Dieter; Plendl, Hansjoerg; Sutter, Christian; Wappenschmidt, Barbara; Borg, Ake; Melin, Beatrice; Rantala, Johanna; Soller, Maria; Nathanson, Katherine L.; Domchek, Susan M.; Rodriguez, Gustavo C.; Salani, Ritu; Kaulich, Daphne Gschwantler; tea, Muy-Kheng; Paluch, Shani Shimon; Laitman, Yael; Skytte, Anne-Bine; Kruse, Torben A.; Jensen, Uffe Birk; Robson, Mark; Gerdes, Anne-Marie; Ejlertsen, Bent; Foretova, Lenka; Savage, Sharon A.; Lester, Jenny; Soucy, Penny; Kuchenbaecker, Karoline B.; Olswold, Curtis; Cunningham, Julie M.; Slager, Susan; Pankratz, Vernon S.; Dicks, Ed; Lakhani, Sunil R.; Couch, Fergus J.; Hall, Per; Monteiro, Alvaro N. A.; Gayther, Simon A.; Pharoah, Paul D. P.; Reddel, Roger R.; Goode, Ellen L.; Greene, Mark H.; Easton, Douglas F.; Berchuck, Andrew; Antoniou, Antonis C.; Chenevix-Trench, Georgia; Dunning, Alison M.

    2013-01-01

    TERT-locus SNPs and leukocyte telomere measures are reportedly associated with risks of multiple cancers. Using the Illumina custom genotyping array iCOGs, we analyzed ∼480 SNPs at the TERT locus in breast (n = 103,991), ovarian (n = 39,774) and BRCA1 mutation carrier (n = 11,705) cancer cases and

  17. Quantitative Linkage for Autism Spectrum Disorders Symptoms in Attention-Deficit/Hyperactivity Disorder: Significant Locus on Chromosome 7q11

    Science.gov (United States)

    Nijmeijer, Judith S.; Arias-Vásquez, Alejandro; Rommelse, Nanda N.; Altink, Marieke E.; Buschgens, Cathelijne J.; Fliers, Ellen A.; Franke, Barbara; Minderaa, Ruud B.; Sergeant, Joseph A.; Buitelaar, Jan K.; Hoekstra, Pieter J.; Hartman, Catharina A.

    2014-01-01

    We studied 261 ADHD probands and 354 of their siblings to assess quantitative trait loci associated with autism spectrum disorder symptoms (as measured by the Children's Social Behavior Questionnaire (CSBQ) using a genome-wide linkage approach, followed by locus-wide association analysis. A genome-wide significant locus for the CSBQ subscale…

  18. 9q31.2-rs865686 as a susceptibility locus for estrogen receptor-positive breast cancer

    DEFF Research Database (Denmark)

    Warren, Helen; Dudbridge, Frank; Fletcher, Olivia

    2012-01-01

    Our recent genome-wide association study identified a novel breast cancer susceptibility locus at 9q31.2 (rs865686).......Our recent genome-wide association study identified a novel breast cancer susceptibility locus at 9q31.2 (rs865686)....

  19. Evidence that breast cancer risk at the 2q35 locus is mediated through IGFBP5 regulation

    DEFF Research Database (Denmark)

    Ghoussaini, Maya; Edwards, Stacey L; Michailidou, Kyriaki

    2014-01-01

    GWAS have identified a breast cancer susceptibility locus on 2q35. Here we report the fine mapping of this locus using data from 101,943 subjects from 50 case-control studies. We genotype 276 SNPs using the 'iCOGS' genotyping array and impute genotypes for a further 1,284 using 1000 Genomes Proje...

  20. Evaluation of two multi-locus sequence typing schemes for commensal Escherichia coli from dairy cattle in Washington State.

    Science.gov (United States)

    Ahmed, Sara; Besser, Thomas E; Call, Douglas R; Weissman, Scott J; Jones, Lisa P; Davis, Margaret A

    2016-05-01

    Multi-locus sequence typing (MLST) is a useful system for phylogenetic and epidemiological studies of multidrug-resistant Escherichiacoli. Most studies utilize a seven-locus MLST, but an alternate two-locus typing method (fumC and fimH; CH typing) has been proposed that may offer a similar degree of discrimination at lower cost. Herein, we compare CH typing to the standard seven-locus method for typing commensal E. coli isolates from dairy cattle. In addition, we evaluated alternative combinations of eight loci to identify combinations that maximize discrimination and congruence with standard seven-locus MLST among commensal E. coli while minimizing the cost. We also compared both methods when used for typing uropathogenic E. coli (UPEC). CH typing was less discriminatory for commensal E. coli than the standard seven-locus method (Simpson's Index of Diversity=0.933 [0.902-0.964] and 0.97 [0.96-0.979], respectively). Combining fimH with housekeeping gene loci improved discriminatory power for commensal E. coli from cattle but resulted in poor congruence with MLST. We found that a four-locus typing method including the housekeeping genes adk, purA, gyrB and recA could be used to minimize cost without sacrificing discriminatory power or congruence with Achtman seven-locus MLST when typing commensal E. coli. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Academic Locus of Control, Tendencies Towards Academic Dishonesty and Test Anxiety Levels as the Predictors of Academic Self-Efficacy

    Science.gov (United States)

    Yesilyurt, Etem

    2014-01-01

    Many studies have focused on finding the level of effect that academic locus of control, tendencies towards academic dishonesty, and test anxiety levels have had on academic self-efficacy, and providing a separate explanation ratio for each. The relationship among the effects of the academic locus of control, tendencies towards academic…

  2. Characterization of Dutch Staphylococcus aureus from bovine mastitis using a Multiple Locus Variable Number Tandem Repeat Analysis

    NARCIS (Netherlands)

    Ikawaty, R.; Brouwer, E.C.; Jansen, M.D.; Duijkeren, van E.; Mevius, D.J.; Verhoef, J.; Fluit, A.C.

    2009-01-01

    Current typing methods for Staphylococcus aureus have important drawbacks. We evaluated a Multiple Locus Variable Number Tandem Repeat Analysis (MLVA) scheme with 6 loci which lacks most drawbacks on 85 bovine mastitis isolates from The Netherlands. For each locus the number of repeat units (RU) was

  3. Evidence that breast cancer risk at the 2q35 locus is mediated through IGFBP5 regulation

    NARCIS (Netherlands)

    M. Ghoussaini (Maya); S.L. Edwards (Stacey); K. Michailidou (Kyriaki); S. Nord (Silje); R. Cowper-Sal-lari (Richard); K. Desai (Kinjal); S. Kar (Siddhartha); K.M. Hillman (Kristine); S. Kaufmann (Susanne); D.M. Glubb (Dylan); J. Beesley (Jonathan); J. Dennis (Joe); M.K. Bolla (Manjeet); Q. Wang (Qing); E. Dicks (Ed); Q. Guo (Qi); M.K. Schmidt (Marjanka); M. Shah (Mitul); R.N. Luben (Robert); J. Brown (Judith); K. Czene (Kamila); H. Darabi (Hatef); M. Eriksson (Mats); D. Klevebring (Daniel); S.E. Bojesen (Stig); B.G. Nordestgaard (Børge); S.F. Nielsen (Sune); H. Flyger (Henrik); D. Lambrechts (Diether); B. Thienpont (Bernard); P. Neven (Patrick); H. Wildiers (Hans); A. Broeks (Annegien); L.J. van 't Veer (Laura); E.J.T. Rutgers (Emiel); F.J. Couch (Fergus); J.E. Olson (Janet); B. Hallberg (Boubou); C. Vachon (Celine); J. Chang-Claude (Jenny); A. Rudolph (Anja); P. Seibold (Petra); D. Flesch-Janys (Dieter); J. Peto (Julian); I. dos Santos Silva (Isabel); L.J. Gibson (Lorna); H. Nevanlinna (Heli); T.A. Muranen (Taru); K. Aittomäki (Kristiina); C. Blomqvist (Carl); P. Hall (Per); J. Li (Jingmei); J. Liu (Jianjun); M.K. Humphreys (Manjeet); D. Kang (Daehee); J.-Y. Choi (J.); S.K. Park (Sue); D-Y. Noh (Dong-Young); K. Matsuo (Keitaro); H. Ito (Hidemi); H. Iwata (Hisato); Y. Yatabe (Yasushi); P. Guénel (Pascal); T. Truong (Thérèse); F. Menegaux (Florence); M. Sanchez (Marie); B. Burwinkel (Barbara); F. Marme (Federick); A. Schneeweiss (Andreas); C. Sohn (Christof); A.H. Wu (Anna H.); C.-C. Tseng (Chiu-Chen); D. Van Den Berg (David); D.O. Stram (Daniel O.); J. Benítez (Javier); M.P. Zamora (Pilar); J.I.A. Perez (Jose Ignacio Arias); P. Menéndez (Primitiva); X.-O. Shu (Xiao-Ou); W. Lu (Wei); Y. Gao; Q. Cai (Qiuyin); A. Cox (Angela); S.S. Cross (Simon); M.W.R. Reed (Malcolm); I.L. Andrulis (Irene); J.A. Knight (Julia); G. Glendon (Gord); S. Tchatchou (Sandrine); E.J. Sawyer (Elinor); I.P. Tomlinson (Ian); M. Kerin (Michael); N. Miller (Nicola); C.A. Haiman (Christopher); B.E. Henderson (Brian); F.R. Schumacher (Fredrick); L. Le Marchand (Loic); A. Lindblom (Annika); S. Margolin (Sara); S.-H. Teo (Soo-Hwang); C.H. Yip (Cheng Har); D.S.C. Lee (Daphne S.C.); T.Y. Wong (Tien Yin); M.J. Hooning (Maartje); J.W.M. Martens (John W. M.); J.M. Collée (Margriet); C.H.M. van Deurzen (Carolien); J.L. Hopper (John); M.C. Southey (Melissa); H. Tsimiklis (Helen); M.K. Kapuscinski (Miroslav K.); C-Y. Shen (Chen-Yang); P.-E. Wu (Pei-Ei); J-C. Yu (Jyh-Cherng); S.-T. Chen; G.G. Alnæs (Grethe); A.-L. Borresen-Dale (Anne-Lise); G.G. Giles (Graham); R.L. Milne (Roger); C.A. McLean (Catriona Ann); K.R. Muir (K.); A. Lophatananon (Artitaya); S. Stewart-Brown (Sarah); P. Siriwanarangsan (Pornthep); M. Hartman (Mikael); X. Miao; S.A.B.S. Buhari (Shaik Ahmad Bin Syed); Y.Y. Teo (Yik Ying); P.A. Fasching (Peter); L. Haeberle (Lothar); A.B. Ekici (Arif); M.W. Beckmann (Matthias); H. Brenner (Hermann); A.K. Dieffenbach (Aida Karina); V. Arndt (Volker); C. Stegmaier (Christa); A.J. Swerdlow (Anthony ); A. Ashworth (Alan); N. Orr (Nick); M. Schoemaker (Minouk); M. García-Closas (Montserrat); J.D. Figueroa (Jonine); S.J. Chanock (Stephen); J. Lissowska (Jolanta); J. Simard (Jacques); M.S. Goldberg (Mark); F. Labrèche (France); M. Dumont (Martine); R. Winqvist (Robert); K. Pykäs (Katri); A. Jukkola-Vuorinen (Arja); H. Brauch (Hiltrud); T. Brüning (Thomas); Y.-D. Koto (Yon-Dschun); P. Radice (Paolo); P. Peterlongo (Paolo); B. Bonnani (Bernardo); S. Volorio (Sara); T. Dörk (Thilo); N.V. Bogdanova (Natalia); S. Helbig (Sonja); A. Mannermaa (Arto); V. Kataja (Vesa); V-M. Kosma (Veli-Matti); J.M. Hartikainen (J.); P. Devilee (Peter); R.A.E.M. Tollenaar (Rob); C.M. Seynaeve (Caroline); C.J. van Asperen (Christi); A. Jakubowska (Anna); J. Lubinski (Jan); K. Jaworska-Bieniek (Katarzyna); K. Durda (Katarzyna); S. Slager (Susan); A.E. Toland (Amanda); C.B. Ambrosone (Christine); D. Yannoukakos (Drakoulis); S. Sangrajrang (Suleeporn); V. Gaborieau (Valerie); P. Brennan (Paul); J.D. McKay (James); U. Hamann (Ute); D. Torres (Diana); W. Zheng (Wei); J. Long (Jirong); H. Anton-Culver (Hoda); S.L. Neuhausen (Susan); C. Luccarini (Craig); C. Baynes (Caroline); S. Ahmed (Shahana); M. Maranian (Melanie); S. Healey (Sue); A. González-Neira (Anna); G. Pita (Guillermo); M.R. Alonso (Rosario); N. Álvarez (Nuria); D. Herrero (Daniel); D.C. Tessier (Daniel C.); D. Vincent (Daniel); F. Bacot (Francois); I. de Santiago (Ines); J. Carroll (Jason); C. Caldas (Carlos); M. Brown (Melissa); M. Lupien (Mathieu); V. Kristensen (Vessela); P.D.P. Pharoah (Paul); G. Chenevix-Trench (Georgia); J.D. French (Juliet); D.F. Easton (Douglas); A.M. Dunning (Alison); P. Webb (Penny); A. De Fazio (Anna)

    2014-01-01

    textabstractGWAS have identified a breast cancer susceptibility locus on 2q35. Here we report the fine mapping of this locus using data from 101,943 subjects from 50 case-control studies. We genotype 276 SNPs using the 'iCOGS' genotyping array and impute genotypes for a further 1,284 using 1000

  4. Multiple independent variants at the TERT locus are associated with telomere length and risks of breast and ovarian cancer

    DEFF Research Database (Denmark)

    Bojesen, Stig Egil; Pooley, Karen A; Johnatty, Sharon E

    2013-01-01

    TERT-locus SNPs and leukocyte telomere measures are reportedly associated with risks of multiple cancers. Using the Illumina custom genotyping array iCOGs, we analyzed ∼480 SNPs at the TERT locus in breast (n = 103,991), ovarian (n = 39,774) and BRCA1 mutation carrier (n = 11,705) cancer cases...

  5. Human γ-globin genes silenced independently of other genes in the β-globin locus.

    NARCIS (Netherlands)

    N.O. Dillon (Niall); F.G. Grosveld (Frank)

    1991-01-01

    textabstractErythropoiesis during human development is characterized by switches in expression of beta-like globin genes during the transition from the embryonic through fetal to adult stages. Activation and high-level expression of the genes is directed by the locus control region (LCR), located 5'

  6. Identification of DIO2 as a new susceptibility locus for symptomatic osteoarthritis

    NARCIS (Netherlands)

    I. Meulenbelt (Ingrid); J. Min (Josine); S.D. Bos (Steffan); N. Riyazi (Naghmeh); J.J. Houwing-Duistermaat (Jeanine); H.J. van der Wijk; H.M. Kroon (Herman); M. Nakajima; S. Ikegawa (Shiro); A.G. Uitterlinden (André); J.B.J. van Meurs (Joyce); W.M. van der Deure (Wendy); T.J. Visser (Theo); A.B. Seymour (Albert); N. Lakenberg (Nico); R. van der Breggen (Ruud); D. Kremer (Dennis); P. Tikka-Kleemola (Päivi); M. Kloppenburg (Margreet); J. Loughlin (John); P.E. Slagboom (Eline)

    2008-01-01

    textabstractOsteoarthritis [MIM 165720] is a common late-onset articular joint disease for which no pharmaceutical intervention is available to attenuate the cartilage degeneration. To identify a new osteoarthritis susceptibility locus, a genome-wide linkage scan and combined linkage association

  7. Deletion of tumor progression locus 2 attenuates alcohol induced hepatic inflammation

    Science.gov (United States)

    BACKGROUND: The pathogenesis of alcoholic liver disease (ALD) involves the interaction of several inflammatory signaling pathways. Tumor progression locus 2 (TPL2), also known as Cancer Osaka Thyroid (COT) and MAP3K8, is a serine threonine kinase that functions as a critical regulator of inflammator...

  8. Parenting Styles and Bullying at School: The Mediating Role of Locus of Control

    Science.gov (United States)

    Georgiou, Stelios N.; Ioannou, Myria; Stavrinides, Panayiotis

    2017-01-01

    The current study examined the mediating role of children's locus of control in the relation between parenting styles and bully-victim experiences at school. Participants were 447 students aged 10 and 11 years old from 13 different elementary, urban, and rural schools in Cyprus. Analyses using structural equation modeling showed that parenting…

  9. Career Locus of Control and Career Success among Chinese Employees: A Multidimensional Approach

    Science.gov (United States)

    Guan, Yanjun; Wang, Zhen; Dong, Zhilin; Liu, Yukun; Yue, Yumeng; Liu, Haiyang; Zhang, Yuqing; Zhou, Wenxia; Liu, Haihua

    2013-01-01

    The current research aimed to develop a multidimensional measure of career locus of control (LOC) and examine its predictive validity on objective and subjective career success among Chinese employees. Items of career LOC were generated based on literature review of the significant predictors of career success, as well as the open-ended responses…

  10. Single-locus complementary sex determination in the inbreeding wasp Euodynerus foraminatus Saussure (Hymenoptera: Vespidae).

    Science.gov (United States)

    Stahlhut, J K; Cowan, D P

    2004-03-01

    The Hymenoptera have arrhenotokous haplodiploidy in which males normally develop from unfertilized eggs and are haploid, while females develop from fertilized eggs and are diploid. Multiple sex determination systems are known to underlie haplodiploidy, and the best understood is single-locus complementary sex determination (sl-CSD) in which sex is determined at a single polymorphic locus. Individuals heterozygous at the sex locus develop as females; individuals that are hemizygous (haploid) or homozygous (diploid) at the sex locus develop as males. sl-CSD can be detected with inbreeding experiments that produce diploid males in predictable proportions as well as sex ratio shifts due to diploid male production. This sex determination system is considered incompatible with inbreeding because the ensuing increase in homozygosity increases the production of diploid males that are inviable or infertile, imposing a high cost on matings between close relatives. However, in the solitary hunting wasp Euodynerus foraminatus, a species suspected of having sl-CSD, inbreeding may be common due to a high incidence of sibling matings at natal nests. In laboratory crosses with E. foraminatus, we find that sex ratios and diploid male production (detected as microsatellite heterozygosity) are consistent with sl-CSD, but not with other sex determination systems. This is the first documented example of sl-CSD in a hymenopteran with an apparent natural history of inbreeding, and thus presents a paradox for our understanding of hymenopteran genetics.

  11. Self-Efficacy and Locus of Control as Predictors of Academic ...

    African Journals Online (AJOL)

    the procrastination behaviour of 300 undergraduate students from a Nigerian university. The participants responded to three valid scales (General Perceived Self Efficacy Scale, Locus of Control Scale and the procrastination scale). Data was analyzed using the Pearson product moment correlation and Multiple regression ...

  12. Work-family conflict, locus of control, and women's well-being: tests of alternative pathways.

    Science.gov (United States)

    Noor, Noraini M

    2002-10-01

    The author tested for the 3 possible pathways (i.e., direct, moderator, and mediator effects) in which locus of control can influence the relationship between work-family conflict and well-being. The author predicted that work-family conflict would be negatively correlated with well-being. In a sample of 310 Malaysian employed women with families, work-family conflict was a significant predictor of both job satisfaction and distress--negatively related to job satisfaction and positively related to symptoms of distress. More important, the results provided support for the effects of all 3 pathways of control on the relationship between work-family conflict and well-being, depending on the outcome measure: For job satisfaction, locus of control had direct effects, acted as a partial mediator, and played a significant moderating role. In contrast, only the direct effect of locus of control predicted distress. The author discusses those findings with reference to the literature on work-family conflict, locus of control, and the issue of stress-distress specificity.

  13. An Investigation of Academic Procrastination, Locus of Control, and Emotional Intelligence

    Science.gov (United States)

    Deniz, M. Engin; Tras, Zeliha; Aydogan, Didem

    2009-01-01

    In this research, the effects of emotional intelligence on the academic procrastination and locus of control tendencies of a group of university students are investigated. The sample of this study consists of 435 university students including 273 female students and 162 male students who were randomly selected from the population of Selcuk…

  14. Effects of Locus of Control, Academic Self-Efficacy, and Tutoring on Academic Performance

    Science.gov (United States)

    Drago, Anthony; Rheinheimer, David C.; Detweiler, Thomas N.

    2018-01-01

    This study investigated the connection between locus of control (LOC), academic self-efficacy (ASE), and academic performance, and whether these variables are affected by tutoring. Additional variables of interest, including gender, students' Pell Grant status, ethnicity, and class size, were also considered for the research models. The population…

  15. Ancient roots for polymorphism at the HLA-DQ. alpha. locus in primates

    Energy Technology Data Exchange (ETDEWEB)

    Gyllensten, U.B.; Erlich, H.A. (Cetus Corp., Emeryville, CA (USA))

    1989-12-01

    The genes encoding the human histocompatibility antigens (HLA) exhibit a remarkable degree of polymorphism as revealed by immunologic and molecular analyses. This extensive sequence polymorphism either may have been generated during the lifetime of the human species or could have arisen before speciation and been maintained in the contemporary human population by selection or, possibly, by genetic drift. These two hypotheses were examined using the polymerase chain reaction method to amplify polymorphic sequences from the DQ{alpha} locus, as well as the DX{alpha} locus, an homologous but nonexpressed locus, in a series of primates that diverged at known times. In general, the amino acid sequence of a specific human DQ{alpha} allelic type is more closely related to its chimpanzee or gorilla counterpart than to other human DQ{alpha} alleles. Phylogenetic analysis of the silent nucleotide position changes shows that the similarity of allelic types between species is due to common ancestry rather than convergent evolution. Thus, most of the polymorphism at the DQ{alpha} locus in the human species was already present at least 5 million years ago in the ancestral species that gave rise to the chimpanzee, gorilla, and human lineages. However, one of the DQ{alpha} alleles may have arisen after speciation by recombination between two ancestral alleles.

  16. Locus of Control and Level of Conflict as Correlates of Immortality Orientation.

    Science.gov (United States)

    O'Dowd, William

    1985-01-01

    Assessed the orientation of 14 male professors toward immortality as a psychological motive. Results showed a generally low conscious concern with immortality issues; however, respondents who have accepted some sort of immortality show a more internal locus of control and better adjustment. (JAC)

  17. Parenting Styles Influence on Locus of Control, Self-Efficacy and Academic Adjustment in College Students

    Science.gov (United States)

    Mills, Kimberly Tracey

    2010-01-01

    The purpose of this study was to investigate the relationship between perceived parenting style, locus of control, self-efficacy, and student outcome (i.e. academic performance, GPA) in a sample of college students. The relationship among gender and ethnicity were also examined across these variables. There were 100 participants in this study,…

  18. The Correlation of Nurses' job Burnout and Their Social Responsibility Considering the Role of Control Locus

    Directory of Open Access Journals (Sweden)

    Reyhane Izedi

    2016-07-01

    Full Text Available Background: Job burnout is an occupational hazard that reduces physical and mental energy of the staff. This study was aimed to investigate the relationship between the nurses' job burnout and their social responsibility considering the moderating role of control locus. Methods: In an analytical and cross-sectional study we used 3 valid questionnaires including Maslach burnout inventory, Dynson social responsibility and Rotter locus of control in 3 educational hospitals of Yazd, Iran. A total of 246 nurses contributed in the study. Data analysis was done through SPSS19. We used Pearson and Kendall correlation coefficient in data analysis. Findings: The mean scores of job burnout and social responsibility of studied group were 60.75 +8.37 and 71.84+15.47, respectively. Job burnout is negatively correlated with social responsibility statistically (r= -0.250 while locus of control acts as the moderator of this correlation. Conclusion: Our results suggest that creating a supportive work environment for nurses enhances their social responsibility trough affecting their level of job burnout. Also, the approved moderating role of control locus in the relationship of job burnout and social responsibility indicates that the personality traits can be considered as the appropriate criteria for entry to nursing schools.

  19. Locus of Word Frequency Effects in Spelling to Dictation: Still at the Orthographic Level!

    Science.gov (United States)

    Bonin, Patrick; Laroche, Betty; Perret, Cyril

    2016-01-01

    The present study was aimed at testing the locus of word frequency effects in spelling to dictation: Are they located at the level of spoken word recognition (Chua & Rickard Liow, 2014) or at the level of the orthographic output lexicon (Delattre, Bonin, & Barry, 2006)? Words that varied on objective word frequency and on phonological…

  20. The temporal locus of the interaction between working memory consolidation and the attentional blink

    NARCIS (Netherlands)

    Akyürek, E.G.; Leszczyński, Marcin; Schubö, Anna

    2010-01-01

    An increase in concurrent working memory load has been shown to amplify the attentional blink. The present study investigated the temporal locus of this phenomenon, by using a dual rapid serial visual presentation paradigm that enabled the measurement of lateralized event-related potentials. The P3

  1. Analysis of fast neutron-generated mutants at the Arabidopsis thaliana HY4 locus

    International Nuclear Information System (INIS)

    Bruggemann, E.; Handwerger, K.; Essex, C.; Storz, G.

    1996-01-01

    Ionizing radiation is expected to produce mutants with deletions or other chromosomal rearrangements. These mutants are useful for a variety of purposes, such as creating null alleles and cloning genes whose existence is known only from their mutant phenotype; however, only a few mutations generated by ionizing radiation have been characterized at the molecular level in Arabidopsis thaliana. Twenty fast neutron-generated alleles of the Arabidopsis HY4 locus, which encodes a blue light receptor, CRY1, were isolated and characterized. Nine of the mutant alleles displayed normal genetic behavior. The other 11 mutant alleles were poorly transmitted through the male gametophyte and were lethal in homozygous plants. Southern blot analysis demonstrated that alleles of the first group generally contain small or moderate-sized deletions at HY4, while alleles of the second group contain large deletions at this locus. These results demonstrate that fast neutrons can produce a range of deletions at a single locus in Arabidopsis. Many of these deletions would be suitable for cloning by genomic subtraction or representational difference analysis. The results also suggest the presence of an essential locus adjacent to HY4. (author)

  2. Locus of Control, Death Anxiety and Length of Service of Electricity ...

    African Journals Online (AJOL)

    This study investigated the relationship between locus of control and death anxiety among staff of an electricity company (Power Holding Company of Nigeria, Plc). Enugu. The participants were 80 workers drawn from Power Holding Company of Nigeria, Plc Okpara Avenue, Enugu 40 long serving staff, 40 short serving staff ...

  3. Influence of socioeconomic status on the relationship between locus of control and oral health.

    Science.gov (United States)

    Acharya, Shashidhar; Pentapati, Kalyana Chakravarthy; Singh, Sweta

    2011-01-01

    The objectives of this study were to assess the relationship between Locus of Control (LoC) and oral health among a group of rural adolescent school children and to examine the influence of socioeconomic status (SES) on the association between health, LoC and oral health status. A total of 318 children 15 years of age from a public and private school formed the study population. The children were administered following the Indian translation of the 18-item Multidimensional Health Locus of Control scale, and subsequently examined for caries and oral hygiene. T tests and correlation analyses showed a significant relationship between higher 'Internal' Locus of Control and dental caries. A hierarchical multiple regression analysis was performed to assess the effect of socioeconomic status on LoC and oral health using three interaction models which showed a statistically significant interaction between 'Internal' LoC and socioeconomic status on caries. Socioeconomic stratum-specific estimates of the relationship between the LoC and caries revealed a positive association between Internal LoC and caries in the middle socioeconomic group. The results demonstrated the relationship between Locus of Control and oral health, and the role of socioeconomic status having a strong bearing on this relationship.

  4. LOCUS-COERULEUS PROJECTIONS TO THE DORSAL MOTOR VAGUS NUCLEUS IN THE RAT

    NARCIS (Netherlands)

    TERHORST, GJ; TOES, GJ; VANWILLIGEN, JD

    1991-01-01

    The origin of the noradrenergic innervation of the preganglionic autonomic nuclei in the medulla oblongata and spinal cord is still controversial. In this investigation descending connections of the locus coeruleus to the dorsal motor vagus nucleus in the rat are studied with Phaseolus vulgaris

  5. Psychosocial work conditions, unemployment and health locus of control: a population-based study.

    Science.gov (United States)

    Sadiq Mohammad Ali; Lindström, Martin

    2008-06-01

    To investigate the association between psychosocial work conditions, unemployment and lack of belief in the possibility of influencing one's own health. The 2000 public health survey in Scania is a cross-sectional postal questionnaire study with a 59% participation rate. In total, 5180 persons aged 18-64 years who belonged to the workforce and the unemployed were included in this study. Logistic regression models were used to investigate the associations between psychosocial factors at work and unemployment, and lack of belief in the possibility of influencing one's own health (external locus of control). Psychosocial conditions at work were defined according to the Karasek-Theorell demand-control/decision latitudes into relaxed, active, passive, and job strain categories. The multivariate analyses included age, country of birth, education, economic stress, and social participation. In total, 26.6% of all men and 26.9% of all women lack an internal locus of control. The passive, job strain and unemployed categories have significantly higher odds ratios of lack of internal locus of control, as compared to the relaxed reference category. No such significant differences are observed for the active category. These patterns remain in the multivariate models, with the exception of the passive and unemployed categories among men, in which the significant differences disappear. Psychosocial work conditions and unemployment may affect health locus of control. The control dimension in the Karasek-Theorell model seems to be of greatest importance.

  6. Perceived Social Support and Locus of Control as the Predictors of Vocational Outcome Expectations

    Science.gov (United States)

    Isik, Erkan

    2013-01-01

    The purpose of this study was to examine the relationships of vocational outcome expectation to social support which is an environmental factor and locus of control which is a personal factor. With this purpose, using Social Cognitive Career Theory as the theoretical framework, 263 undergraduate students completed Vocational Outcome Expectations…

  7. A Dual Reporter Mouse Model of the Human β-Globin Locus: Applications and Limitations

    NARCIS (Netherlands)

    P. Papadopoulos (Petros); L. Gutiérrez (Laura); R. van der Linden (Reinier); J. Kong-a-San (John); A. Maas (Alex); D.D. Drabek (Dubravka); G.P. Patrinos (George); J.N.J. Philipsen (Sjaak); F.G. Grosveld (Frank)

    2012-01-01

    textabstractThe human β-globin locus contains the β-like globin genes (i.e. fetal γ-globin and adult β-globin), which heterotetramerize with α-globin subunits to form fetal or adult hemoglobin. Thalassemia is one of the commonest inherited disorders in the world, which results in quantitative

  8. Genomewide scan identifies susceptibility locus for dyslexia on Xq27 in an extended Dutch family.

    Science.gov (United States)

    de Kovel, C G F; Hol, F A; Heister, J G A M; Willemen, J J H T; Sandkuijl, L A; Franke, B; Padberg, G W

    2004-09-01

    Dyslexia is a common disorder with a strong genetic component, but despite significant research effort, the aetiology is still largely unknown. To identify loci contributing to dyslexia risk. This was a genomewide linkage analysis in a single large family. Dutch families with at least two first degree relatives suffering from dyslexia participated in the study. Participants were recruited through an advertisement campaign in papers and magazines. The main outcome measure was linkage between genetic markers and dyslexia phenotype. Using parametric linkage analysis, we found strong evidence for a locus influencing dyslexia on Xq27.3 (multipoint lod = 3.68). Recombinations in two family members flanked an 8 cM region, comprising 11 currently confirmed genes. All four males carrying the risk haplotype had very low scores on the reading tests. The presentation in females was more variable, but 8/9 females carrying the risk haplotype were diagnosed dyslexic by our composite score, so we considered the putative risk allele to be dominant with reduced penetrance. Linkage was not found in an additional collection of affected sibling pairs. A locus influencing dyslexia risk is probably located between markers DXS1227 and DXS8091 on the X chromosome, closely situated to a locus indicated by a published genome scan of English sibling pairs. Although the locus may not be a common cause for dyslexia, the relatively small and gene poor region offers hope to identify the responsible gene.

  9. Impact of Computer Expertise, Locus of Control and Self-Esteem on ...

    African Journals Online (AJOL)

    The present study considered the influence of self-esteem, locus of control and computer expertise on computer-induced stress in a cross sectional survey. One hundred and fifty cyber café users drawn from 10 cyber cafes randomly chosen from University of Ibadan and its environs participated in the study. Of the 150 ...

  10. Internal versus External Control of Reinforcement: A Review of the Locus of Control Construct

    Science.gov (United States)

    Kormanik, Martin B.; Rocco, Tonette S.

    2009-01-01

    One aspect of personality, perceptions of internal versus external control of reinforcement, shifts under conditions of change. This review of the literature examines the relationship between planned organizational change and locus of control. The review includes literature from the disciplines of clinical and social psychology, adult development,…

  11. Locus of Control, Psychopathology, and Weight Gain in Juvenile Anorexia Nervosa.

    Science.gov (United States)

    Strober, Michael

    1982-01-01

    Based on a hypothesized disturbance in personal control and efficacy in anorexia nervosa, locus of control score in female adolescents with anorexia nervosa was compared to scores obtained from depressed and conduct-disordered controls and to adolescent female standardization norms. (Author/CL)

  12. Human obesity associated with an intronic SNP in the brain-derived neurotrophic factor locus

    Science.gov (United States)

    Brain-derived neurotrophic factor (BDNF) plays a key role in energy balance. In population studies, SNPs of the BDNF locus have been linked to obesity, but the mechanism by which these variants cause weight gain is unknown. Here, we examined human hypothalamic BDNF expression in association with 44 ...

  13. Coping strategies and locus of control in childhood leukemia: a multi-center research

    Directory of Open Access Journals (Sweden)

    Concetta Polizzi

    2015-06-01

    Full Text Available Acute lymphoblastic leukemia (ALL is a very distressing experience for children and requires a special effort of adjustment. Therefore, it seems to be crucial to explore coping resources for the experienced risk condition. In this sense, the study focuses on coping strategies and locus of control in children with ALL during the treatment phase, and on their possible relation. The correlation between children and maternal coping strategies is also investigated. The participants involved were an experimental group of 40 children with ALL and their mothers, and 30 healthy children as the control group. The tools used were: the Child Behavioral Style Scale and the Monitor-Blunter Style Scale to assess the coping strategies of children and mothers; the locus of Control Scale for Children to analyze the children’s perception of controlling the events. Both children with ALL and their mothers resorted to monitoring coping strategies with a statistically significant rate of occurrence (children: M=17.8, SD=3.8; mothers: M=10.48, SD=3.4. The data concerning the locus of control show this tendency towards internal causes (M=53.1, SD=4.7. There were statistically significant correlations between monitoring coping strategies and external locus of control (r=0.400, P<0.05. The results gained from the control group are almost equivalent. The outcomes show several interesting resources of the psychological functioning of children as well as of their mothers.

  14. A Reliability Generalization Study of Scores on Rotter's and Nowicki-Strickland's Locus of Control Scales

    Science.gov (United States)

    Beretvas, S. Natasha; Suizzo, Marie-Anne; Durham, Jennifer A.; Yarnell, Lisa M.

    2008-01-01

    The most commonly used measures of locus of control are Rotter's Internality-Externality Scale (I-E) and Nowicki and Strickland's Internality-Externality Scale (NSIE). A reliability generalization study is conducted to explore variability in I-E and NSIE score reliability. Studies are coded for aspects of the scales used (number of response…

  15. Self-Esteem, Locus of Control and Various Aspects of Psychopathology of Adults with Visual Impairments

    Science.gov (United States)

    Papadopoulos, Konstantinos; Paralikas, Theodosis; Barouti, Marialena; Chronopoulou, Elena

    2014-01-01

    The exploratory study presented in this article looks into the possible differences in psychosocial aspects (self-esteem and locus of control) and aspects of psychopathology (depression, anxiety, melancholia, asthenia, and mania) amongst sighted adults and adults with visual impairments. Moreover, the study aims to examine the possible…

  16. General self-esteem and locus of control of young sportsmen

    Directory of Open Access Journals (Sweden)

    Gašić-Pavišić Slobodanka

    2006-01-01

    Full Text Available This paper deals with the relationship between some elements of self-concept (general self-esteem and locus of control and going in for sport in adolescence. The relationship between going in for sport and variables of self-concept (general self-esteem and external locus of control was investigated in a sample of 300 adolescent boys and girls (150 sportsmen and 150 non-sportsmen. Modification of the Rosenberg’s General self-esteem scale and Bezinović-Savčić’s Scale of externality were used to measure variables of self-concept. The significant positive correlation between variables of going in for sport and general selfesteem, as well as negative ones between variables of going in for sport and external locus of control were found in the whole sample of subjects and in the sample of boys, but not of girls. The sex role stereotypes and greater importance that the culture puts on success in sport for boys have contributed to such results. The sex differences in correlations between variables of self-concept and going in for sport suggest that going in for sport influences general self-esteem and locus of control in adolescents through social feedback and social evaluation of sport achievement and physical fitness. .

  17. The Effect of Compensation Studies on Disadvantaged Children's Self Concept Levels and Locus of Control

    Science.gov (United States)

    Sadioglu, Ömür

    2017-01-01

    The aim of this study is to determine the effect of "Bir Umut Ol Benim Için" (Be My Hope) project which was prepared for the children who were disadvantaged by being influenced from several risk factors as compared to their peers on the self-concepts and locus of controls of the children. The study group consisted of 33 children who were…

  18. Parental Locus of Control and Psychological Well-Being in Mothers of Children with Intellectual Disability

    Science.gov (United States)

    Lloyd, Tracey; Hastings, Richard P.

    2009-01-01

    Background: Psychological mechanisms may help to explain the variance observed in parental psychological adjustment in parents of children with intellectual disability (ID). In this study, parental locus of control and its role in relation to maternal psychological well-being was explored. Method: Questionnaires were sent to 91 mothers of children…

  19. Learning to Learn Online: Using Locus of Control to Help Students Become Successful Online Learners

    Science.gov (United States)

    Lowes, Susan; Lin, Peiyi

    2015-01-01

    In this study, approximately 600 online high school students were asked to take Rotter's locus of control questionnaire and then reflect on the results, with the goal of helping them think about their ability to regulate their learning in this new environment. In addition, it was hoped that the results could provide a diagnostic for teachers who…

  20. Democratic Teacher Beliefs According to the Teacher's Gender and Locus of Control

    Science.gov (United States)

    Kesici, Sahin

    2008-01-01

    This study explored the variations in democratic beliefs among teachers based on gender and locus of control. The study groups comprised of 286 teachers. The results demonstrated that the level of adherence to democratic beliefs on the part of female teachers was significantly higher than those of male teachers, especially in terms of equality and…

  1. Impact of locus of control, religiosity and exercise on depression in a ...

    African Journals Online (AJOL)

    The study assesses the combined effects of locus of control, religiosity, and physical exercise constructs on the global health outcome in depressed patients at the Ahmadu Bello University Teaching Hospital Shika,Zaria. A cross-sectional study design was used; fifteen (15) participants were purposively selected from ...

  2. Health locus of control and self-care behaviors in diabetic foot patients.

    Science.gov (United States)

    Abredari, Hamid; Bolourchifard, Fariba; Rassouli, Maryam; Nasiri, Navideh; Taher, Mohammad; Abedi, Ahmadreza

    2015-01-01

    Diabetic foot affects more than 25% of diabetic patients and finally up to 20% of cases result in amputation. The most important factor resulting in severe complications or even death is lack of self-care. Health locus of control has been introduced as one of health factors and predicting factors of self-care. This research was performed for analyzing the correlation between self-care behaviors and health locus of control in diabetic foot patients. In this descriptive study, 120 patients with diabetic foot were chosen using convenience sampling from endocrine clinic and wards of endocrine and vascular surgery of Teleqani Hospital of Shahid Beheshti Medical University. The data were gathered by demographic, self-care behavior, and health locus of control questionnaires. The t-test, analysis of variance (ANOVA) and spearman coefficient were used to analyze the data. RESULTS of this research showed that there is a direct and significant relation between selfcare behaviors and internal health locus of control (plocus of control (plocus of control improve and strengthen patients' self-care behaviors and their involvement in treatment.

  3. Professional/Career Orientation, Awareness, and Their Relationship to Locus of Control

    Science.gov (United States)

    Algadheeb, Nourah A.

    2015-01-01

    This study aimed at exploring the differences in professional/career orientation and awareness while considering a number of variables including locus of control, academic specialization and school backwardness. Several measures were used to achieve the study's goals. The first two, a professional/career orientation measure and a…

  4. Longitudinal Factor Structure of General Self-Concept and Locus of Control among High School Students

    Science.gov (United States)

    Wang, Ze; Su, Ihui

    2013-01-01

    This study examined the longitudinal factor structure of general self-concept and locus of control among high school students over a 4-year period, with data from the National Educational Longitudinal Study of 1988. Measurement invariance was tested over time and across gender and ethnic groups; second-order piecewise latent growth models were…

  5. Posttraumatic Stress Disorder Following Stillbirth: Trauma Characteristics, Locus of Control, Posttraumatic Cognitions.

    Science.gov (United States)

    Chung, Man Cheung; Reed, Jacqueline

    2017-06-01

    This study examined the incidence of PTSD and psychiatric co-morbidity among women who experienced stillbirth and investigated the relationship between locus of control, trauma characteristics of stillbirth, posttraumatic cognitions, PTSD and co-morbid psychiatric symptoms following stillbirth. Fifty women recorded information on stillbirth experiences, and completed the Posttraumatic Stress Diagnostic Scale, General Health Questionnaire-28, Edinburgh Post-natal Depression Scale, Rotter's Locus of Control Scale and the Posttraumatic Cognitions Inventory. 60, 28 and 12 % met the diagnostic criteria for probable full-PTSD, partial and no-PTSD respectively. Sixty-two percent and 54 % scored at or above the cutoff of the General Health Questionnaire-28 and postnatal depression respectively. Women who experienced stillbirth reported significantly more psychiatric co-morbid and post-natal depressive symptoms than the comparison group. Both groups were similar in locus of control. Women who experienced stillbirth reported negative cognitions about the self the most. After adjusting for postnatal depression, trauma characteristics were significantly correlated with Posttraumatic cognitions which, in turn, were significantly correlated with PTSD and psychiatric co-morbidity. Locus of control was not significantly correlated with psychological outcomes. Mediational analyses showed that negative cognitions about self mediated the relationship between trauma characteristics and psychiatric co-morbidity only. Women reported a high incidence of probable PTSD and co-morbid psychiatric symptoms following stillbirth. Stillbirth trauma characteristics influenced how they negatively perceived themselves. This then specifically influenced general psychological problems rather than PTSD symptoms.

  6. Predicting the Likelihood of Going to Graduate School: The Importance of Locus of Control

    Science.gov (United States)

    Nordstrom, Cynthia R.; Segrist, Dan J.

    2009-01-01

    Although many undergraduates apply to graduate school, only a fraction will be admitted. A question arises as to what factors relate to the likelihood of pursuing graduate studies. The current research examined this question by surveying students in a Careers in Psychology course. We hypothesized that GPA, a more internal locus of control…

  7. Loneliness among people with HIV in relation to locus of control and negative meta-stereotyping

    NARCIS (Netherlands)

    Gordijn, E.H.; Boven, G.

    2009-01-01

    The aim of this research was to examine the relation between locus of control, meta-stereotyping (expectancies about how one's group is stereotyped by another group), and loneliness among people who are HIV-positive. In line with expectations, a survey in the Netherlands among 122 people living with

  8. Students' Commitment, Engagement and Locus of Control as Predictor of Academic Achievement at Higher Education Level

    Science.gov (United States)

    Sarwar, Muhammad; Ashrafi, Ghulam Muhammad

    2014-01-01

    The purpose of this study was to analyze Students' Commitment, Engagement and Locus of Control as predictors of Academic Achievement at Higher Education Level. We used analytical model and conclusive research approach to conduct study and survey method for data collection. We selected 369 students using multistage sampling technique from three…

  9. Caregiver's Health Locus of Control and Medication Adherence in Sickle Cell Disease.

    Science.gov (United States)

    Viswanathan, Kusum; Swaminathan, Neeraja; Viswanathan, Ramaswamy; Lakkaraja, Madhavi

    2015-03-01

    The authors would like to thank Dr. Morisky for giving us permission to use the Morisky Medication Adherence Scale To explore caregivers' Health Locus of Control's relationship to self-reported adherence to penicillin prophylaxis or hydroxyurea in children with sickle cell disease (SCD). A questionnaire-based study was conducted of caregivers of children with SCD who visited a comprehensive sickle cell center in an inner city hospital, who were either on penicillin prophylaxis or hydroxyurea or both. Multidimensional Health Locus of Control Scale (MHLC) and the Morisky Medication Adherence Scale (MMAS-8) questionnaires were used for the study. Caregivers of 43 children (27 on penicillin prophylaxis, 13 on hydroxyurea, and 3 on both) completed the MHLC and the MMAS-8. There was no significant difference in adherence between the penicillin and the hydroxyurea groups. The mean Powerful Others score of caregivers of the hydroxyurea only group (25.5+5.6) was higher than that of the penicillin only group (21.2+6.1, p=0.043). Regression analysis revealed an inverse relationship of Chance Locus of Control to adherence in the entire group (Beta = -0.306, R2=0.093, F[1,40]=4.12, p=0.049). Chance Locus of control may identify caregivers of children with SCD at risk for non-adherence to treatment. © 2015 National Medical Association. Published by Elsevier Inc. All rights reserved.

  10. Effects of Locus of Control and Learner-Control on Web-Based Language Learning

    Science.gov (United States)

    Chang, Mei-Mei; Ho, Chiung-Mei

    2009-01-01

    The study explored the effects of students' locus of control and types of control over instruction on their self-efficacy and performance in a web-based language learning environment. A web-based interactive instructional program focusing on the comprehension of news articles for English language learners was developed in two versions: learner-…

  11. The Relationship between Critical Thinking Disposition and Locus of Control in Pre-Service Teachers

    Science.gov (United States)

    Oguz, Aytunga; Sariçam, Hakan

    2016-01-01

    The aim of the current research study was to examine the link between critical thinking dispositions and locus of control in pre-service teachers. The participants of this study were selected via easily accessible sampling technique. The participants consist of 347 pre-service teachers (203 female, 144 male) in Kütahya, Turkey. The Rotter…

  12. Personality disorder, emotional intelligence, and locus of control of patients with alcohol dependence.

    Science.gov (United States)

    Prakash, Om; Sharma, Neelu; Singh, Amool R; Sengar, K S; Chaudhury, Suprakash; Ranjan, Jay Kumar

    2015-01-01

    To assess personality disorder (PD), emotional intelligence (EI), and locus of control of alcohol dependent (AD) patients and its comparison with normal controls. Based on purposive sampling technique, 33 AD patients were selected from the De-Addiction Ward of Ranchi Institute of Neuro-Psychiatry and Allied Sciences (RINPAS) and 33 matched normal subjects were selected from Ranchi and nearby places. Both the groups were matched on various sociodemographic parameters, that is, age, gender, and socioeconomic level. All participants were assessed with Millon Clinical Multiaxial Inventory-III, Mangal EI Inventory, and Locus of Control scale. Obtained responses were scored by using standard scoring procedures and subsequently statistically analyzed by using Chi-square test. AD patients have more comorbid pathological personality traits and disorders in comparison to their normal counterparts. Depressive, narcissistic, and paranoid PDs were prominent among AD group; followed by schizotypal, antisocial, negativistic, dependent, schizoid, sadistic, masochistic, and borderline PD. In comparison to normal participants, AD patients were significantly deficient in almost all the areas of EI and their locus of control was externally oriented. Patients with AD have significantly higher PDs, low EI, and an external orientation on the locus of control. Identification and management of these comorbid conditions are likely to improve the management and outcome of AD.

  13. Locus pietatis et vitae II, Vranov u Brna 20.–22. 9. 2010

    Czech Academy of Sciences Publication Activity Database

    Freemanová, Michaela

    2010-01-01

    Roč. 47, č. 4 (2010), s. 407-409 ISSN 0018-7003. [Locus pietatis et vitae II. Vranov u Brna, 20.09.2010–22.09.2010] Institutional research plan: CEZ:AV0Z90580513 Keywords : history * monastic orders * conference Subject RIV: AL - Art, Architecture, Cultural Heritage

  14. Effects of Death Education on Nursing Students' Anxiety and Locus of Control.

    Science.gov (United States)

    Yarber, William L.; And Others

    1981-01-01

    A study was done to determine the impact of a death education course on the relationship between nursing students' death anxiety and locus of control. No significant changes occurred in death avoidance, death fear, death denial, and the reluctance to interact with the dying after the 15-week course. (JN)

  15. Insertional inactivation of a chromosomal locus that modulates expression of potential virulence determinants in Staphylococcus aureus.

    Science.gov (United States)

    Cheung, A L; Wolz, C; Yeaman, M R; Bayer, A S

    1995-06-01

    A single insertion of transposon Tn551 into a unique chromosomal locus of Staphylococcus aureus ISP479C has resulted in a pleiotropic effect on the expression of both extracellular and cell wall proteins. In particular, the expression of cell wall protein A and clumping activity with fibrinogen were rendered undetectable in the mutant 1E3 compared with the parent. The secretion of alpha-hemolysin in mutant 1E3 was modestly increased. Southern blot and phenotypic analyses indicated that this locus is distinct from agr, xpr, and sar, three previously described global regulatory loci. Transduction experiments demonstrated that the genotype associated with mutant 1E3 could be transferred back into the parental strain ISP479C. The transductant 1E3-2 displayed a phenotypic profile similar to that of the original mutant. Northern (RNA) blot studies showed that this locus may be involved in modulating target genes at the mRNA level. In the rabbit endocarditis model, there was a significant decrease in both the infectivity rate and intravegetation bacterial density with mutant 1E3 compared with the parent at an inoculum of 10(3) CFU. Since protein A and the fibrinogen-binding protein(s) are major surface proteins that may mediate bacterial adhesion to host tissues, this locus may be an important genetic element involved in the expression of virulence determinants in S. aureus.

  16. Sex and Locus of Control as Determinants of Children's Responses to Peer versus Adult Praise.

    Science.gov (United States)

    Henry, Susan E.; And Others

    1979-01-01

    Black first graders varying in internal-external control completed digit substitution problems during which performance was praised by a Black boy and girl or a Black man and woman. Boys were most responsive to peer feedback and girls to adult feedback. Predictions involving locus of control were modestly supported. (Author/RD)

  17. Assessing God Locus of Control as a Factor in College Students' Alcohol Use and Sexual Behavior

    Science.gov (United States)

    Moore, Erin W.

    2014-01-01

    Objectives: This study explored God locus of control beliefs (ie, God's control over behavior) regarding their influence on alcohol use and sexual behavior as an alternative religiosity measure to religious behaviors, which does not capture perceived influence of religiosity. Additionally, demographic differences in religious beliefs were…

  18. Influence of locus of control on conformity to authority in a ...

    African Journals Online (AJOL)

    Influence of locus of control on conformity to authority in a multicultural organisation - A case of IITA Nigeria. John O Ekore. Abstract. No Abstract Available African Journal for the Psychological Study of Social Issues Vol.5(2) 2000: 90-96. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT ...

  19. High School Students' Career Decision-Making Difficulties According to Locus of Control

    Science.gov (United States)

    Kirdök, Oguzhan; Harman, Esranur

    2018-01-01

    This study intends to elaborate upon difficulties in career decisions of high school students with different locus of control. 9th, 10th, 11th and 12th grade students aged 14-19, 282 (%55.4) females, 227 (%44.6) males totaling 509 participants involved in research located in the south of Turkey. Career Decision-Making Difficulties Questionnaire…

  20. computer-aided root aided root aided root aided root-locus

    African Journals Online (AJOL)

    User

    m, stability, transient response, root-locus, iteration he means by which any a machine, mechanism or d or altered in accordance. Introduction of feedback has the advantages of f system performance to in system parameters, ponse and minimizing the ignals. However, feedback of components, increases ain and introduces ...

  1. Coarticulation in Early Vocalizations by Children with Hearing Loss: A Locus Perspective

    Science.gov (United States)

    Morrison, Helen Mccaffrey

    2012-01-01

    Locus equations derived from productions by three children with hearing loss revealed sensory and motor influences on anticipatory coarticulation. Participants who received auditory access to speech via hearing aids and cochlear implants at different ages (5-39 months) were recorded at approximately 6 and 12 months after hearing technology…

  2. Rangewide Genetic Variation in Coast Redwood Populations at a Chloroplast Microsatellite Locus

    Science.gov (United States)

    Chris Brinegar

    2012-01-01

    Old growth and second growth populations of coast redwood (Sequoia sempervirens) were sampled at 10 locations throughout its range and analyzed at a highly variable chloroplast microsatellite locus. Very low FST values indicated that there was no significant genetic differentiation between adjacent old growth and second growth populations at each location. Genetic...

  3. Health Locus of Control in Indonesian Women with Breast Cancer: a Comparison with Healthy Women

    NARCIS (Netherlands)

    Iskandarsyah, A.; de Klerk, C.; Suardi, D.R.; Sadarjoen, S.S.; Passchier, J.

    2014-01-01

    The aims of this study were to assess whether Indonesian women with breast cancer havea higher external health locus of control (HLC) than healthy women, and to explore the association between HLC and symptoms of anxiety and depression. In this study, 120 consecutive women with breast cancer were

  4. A simple route to maximum-likelihood estimates of two-locus

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics; Volume 94; Issue 3. A simple route to maximum-likelihood estimates of two-locus recombination fractions under inequality restrictions. Iain L. Macdonald Philasande Nkalashe. Research Note Volume 94 Issue 3 September 2015 pp 479-481 ...

  5. Expression of transgenes targeted to the Gt(ROSA26Sor locus is orientation dependent.

    Directory of Open Access Journals (Sweden)

    Douglas Strathdee

    2006-12-01

    Full Text Available Targeting transgenes to a chosen location in the genome has a number of advantages. A single copy of the DNA construct can be inserted by targeting into regions of chromatin that allow the desired developmental and tissue-specific expression of the transgene.In order to develop a reliable system for reproducibly expressing transgenes it was decided to insert constructs at the Gt(ROSA26Sor locus. A cytomegalovirus (CMV promoter was used to drive expression of the Tetracycline (tet transcriptional activator, rtTA2(s-M2, and test the effectiveness of using the ROSA26 locus to allow transgene expression. The tet operator construct was inserted into one allele of ROSA26 and a tet responder construct controlling expression of EGFP was inserted into the other allele.Expression of the targeted transgenes was shown to be affected by both the presence of selectable marker cassettes and by the orientation of the transgenes with respect to the endogenous ROSA26 promoter. These results suggest that transcriptional interference from the endogenous gene promoter or from promoters in the selectable marker cassettes may be affecting transgene expression at the locus. Additionally we have been able to determine the optimal orientation for transgene expression at the ROSA26 locus.

  6. Adolescent Parenting: Contrasts in Self-Esteem and Locus of Control.

    Science.gov (United States)

    Cook, Ann; Troike, Roger

    Pregnant and parenting adolescents represent a unique and challenging problem for educational systems. Of the 17,051 women who become pregnant every day in America, 2,795 or 16% of them are adolescents. The self-esteem and locus of control of 85 pregnant and parenting teens enrolled in the Ohio Graduation, Reality, Dual Role Skills (GRADS) Program…

  7. Locus of control and self-esteem in depressed, low-income African-American women.

    Science.gov (United States)

    Goodman, S H; Cooley, E L; Sewell, D R; Leavitt, N

    1994-06-01

    Depressed, schizophrenic, and well low-income, African-American women were studied in an effort to extend previous hypotheses of the association between depression and the two personality constructs of low self-esteem and externality to this population. Subjects were 113 low income African-American women including 26 who had been diagnosed as depressed, 54 diagnosed as schizophrenic, and 33 well women. Locus of control was measured with the Adult Nowicki-Strickland Internal-External Control Scale (Nowicki & Duke, 1974). Self-esteem was measured with the Rosenberg Self-Esteem Scale (Rosenberg, 1965). Contrary to predictions, a diagnosis of schizophrenia, but not depression, was associated with more external locus of control. For self-esteem, severity of disturbance, rather than diagnosis, seemed to be of primary importance. Also, lower self-esteem scores were correlated significantly with higher levels of externality for both depressed and schizophrenic women but not for well controls. The present study indicates that self-esteem and locus of control are related to depression differently in low socio-economic status (SES) African-American women than in previously studied middle SES depressed whites. The findings emphasize the need for more normative studies to clarify the complex relations among SES, race, emotional disturbance, self-esteem, and locus of control.

  8. Role Stress Revisited: Job Structuring Antecedents, Work Outcomes, and Moderating Effects of Locus of Control

    Science.gov (United States)

    Conley, Sharon; You, Sukkyung

    2014-01-01

    A previous study examined role stress in relation to work outcomes; in this study, we added job structuring antecedents to a model of role stress and examined the moderating effects of locus of control. Structural equation modeling was used to assess the plausibility of our conceptual model, which specified hypothesized linkages among teachers'…

  9. Genotyping Sugarcane for the Brown Rust Resistance Locus Bru1 Using Unlabeled Probe Melting

    Science.gov (United States)

    Brown rust, caused by the fungus Puccinia melanocephala, is a major disease of sugarcane (Saccharum spp.) in Florida, Louisiana, and other sugarcane growing regions. The Bru1 locus has been used as a durable and effective source of resistance, and markers are available to select for the trait. The...

  10. Personality disorder, emotional intelligence, and locus of control of patients with alcohol dependence

    Directory of Open Access Journals (Sweden)

    Om Prakash

    2015-01-01

    Full Text Available Aim: To assess personality disorder (PD, emotional intelligence (EI, and locus of control of alcohol dependent (AD patients and its comparison with normal controls. Materials and Methods: Based on purposive sampling technique, 33 AD patients were selected from the De-Addiction Ward of Ranchi Institute of Neuro-Psychiatry and Allied Sciences (RINPAS and 33 matched normal subjects were selected from Ranchi and nearby places. Both the groups were matched on various sociodemographic parameters, that is, age, gender, and socioeconomic level. All participants were assessed with Millon Clinical Multiaxial Inventory-III, Mangal EI Inventory, and Locus of Control scale. Obtained responses were scored by using standard scoring procedures and subsequently statistically analyzed by using Chi-square test. Results: AD patients have more comorbid pathological personality traits and disorders in comparison to their normal counterparts. Depressive, narcissistic, and paranoid PDs were prominent among AD group; followed by schizotypal, antisocial, negativistic, dependent, schizoid, sadistic, masochistic, and borderline PD. In comparison to normal participants, AD patients were significantly deficient in almost all the areas of EI and their locus of control was externally oriented. Conclusion: Patients with AD have significantly higher PDs, low EI, and an external orientation on the locus of control. Identification and management of these comorbid conditions are likely to improve the management and outcome of AD.

  11. Heterogeneity at the CETP gene locus. Influence on plasma CETP concentrations and HDL cholesterol levels

    NARCIS (Netherlands)

    Kuivenhoven, J.A.; de Knijff, P.; Boer, J M; Smalheer, H A; Botma, G.J.; Seidell, J C; Kastelein, J.J.; Pritchard, P H

    This study was designed to investigate the association(s) between heterogeneity at the cholesteryl ester transfer protein (CETP) gene locus, CETP plasma concentrations, and HDL cholesterol levels. Healthy men with the lowest, median, and highest deciles of HDL cholesterol were selected from a large

  12. Mothers of Children with Severe Mental Retardation: Maternal Pessimism, Locus of Control and Perceived Social Support.

    Science.gov (United States)

    Rimmerman, Arie

    1991-01-01

    This study, involving 24 Israeli mothers of children (average age 3.3) with severe mental retardation, found that the mothers' locus of control and perception of social support (belonging, appraisal, tangible support, and self-esteem) serve as buffers against parental pessimism concerning their severely handicapped children. (JDD)

  13. Locus of Control, Self-esteem, Stimulus Appraisal, and Depressive Symptoms in Children

    Science.gov (United States)

    Moyal, Barbara R.

    1977-01-01

    Variables of self-esteem, locus of control, stimulus appraisal, and depressive symptoms, which are related to depression in adults, were investigated in a sample of nonreferred Grade 5 and Grade 6 children. Grade and sex effects were not significant. All other intervariable correlations were significant. (Author)

  14. A genetic map of mouse chromosome 1 near the Lsh-Ity-Bcg disease resistance locus.

    Science.gov (United States)

    Mock, B; Krall, M; Blackwell, J; O'Brien, A; Schurr, E; Gros, P; Skamene, E; Potter, M

    1990-05-01

    Isozyme and restriction fragment length polymorphism (RFLP) analyses of backcross progeny, recombinant inbred strains, and congenic strains of mice positioned eight genetic markers with respect to the Lsh-Ity-Bcg disease resistance locus. Allelic isoforms of Idh-1 and Pep-3 and RFLPs detected by Southern hybridization for Myl-1, Cryg, Vil, Achrg, bcl-2, and Ren-1,2, between BALB/cAnPt and DBA/2NPt mice, were utilized to examine the cosegregation of these markers with the Lsh-Ity-Bcg resistance phenotype in 103 backcross progeny. An additional 47 backcross progeny from a cross between C57BL/10ScSn and B10.L-Lshr/s mice were examined for the cosegregation of Myl-1 and Vil RFLPs with Lsh phenotypic differences. Similarly, BXD recombinant inbred strains were typed for RFLPs upon hybridization with Vil and Achrg. Recombination frequencies generated in the different test systems were statistically similar, and villin (Vil) was identified as the molecular marker closest (1.7 +/- 0.8 cM) to the Lsh-Ity-Bcg locus. Two other DNA sequences, nebulin (Neb) and an anonymous DNA fragment (D2S3), which map to a region of human chromosome 2q that is homologous to proximal mouse chromosome 1, were not closely linked to the Lsh-Ity-Bcg locus. This multipoint linkage analysis of chromosome 1 surrounding the Lsh-Ity-Bcg locus provides a basis for the eventual isolation of the disease gene.

  15. Polymorphism in the two-locus Levene model with nonepistatic directional selection.

    Science.gov (United States)

    Bürger, Reinhard

    2009-11-01

    For the Levene model with soft selection in two demes, the maintenance of polymorphism at two diallelic loci is studied. Selection is nonepistatic and dominance is intermediate. Thus, there is directional selection in every deme and at every locus. We assume that selection is in opposite directions in the two demes because otherwise no polymorphism is possible. If at one locus there is no dominance, then a complete analysis of the dynamical and equilibrium properties is performed. In particular, a simple necessary and sufficient condition for the existence of an internal equilibrium and sufficient conditions for global asymptotic stability are obtained. These results are extended to deme-independent degree of dominance at one locus. A perturbation analysis establishes structural stability within the full parameter space. In the absence of genotype-environment interaction, which requires deme-independent dominance at both loci, nongeneric equilibrium behavior occurs, and the introduction of arbitrarily small genotype-environment interaction changes the equilibrium structure and may destroy stable polymorphism. The volume of the parameter space for which a (stable) two-locus polymorphism is maintained is computed numerically. It is investigated how this volume depends on the strength of selection and on the dominance relations. If the favorable allele is (partially) dominant in its deme, more than 20% of all parameter combinations lead to a globally asymptotically stable, fully polymorphic equilibrium.

  16. A two-locus model of spatially varying stabilizing or directional selection on a quantitative trait.

    Science.gov (United States)

    Geroldinger, Ludwig; Bürger, Reinhard

    2014-06-01

    The consequences of spatially varying, stabilizing or directional selection on a quantitative trait in a subdivided population are studied. A deterministic two-locus two-deme model is employed to explore the effects of migration, the degree of divergent selection, and the genetic architecture, i.e., the recombination rate and ratio of locus effects, on the maintenance of genetic variation. The possible equilibrium configurations are determined as functions of the migration rate. They depend crucially on the strength of divergent selection and the genetic architecture. The maximum migration rates are investigated below which a stable fully polymorphic equilibrium or a stable single-locus polymorphism can exist. Under stabilizing selection, but with different optima in the demes, strong recombination may facilitate the maintenance of polymorphism. However usually, and in particular with directional selection in opposite direction, the critical migration rates are maximized by a concentrated genetic architecture, i.e., by a major locus and a tightly linked minor one. Thus, complementing previous work on the evolution of genetic architectures in subdivided populations subject to diversifying selection, it is shown that concentrated architectures may aid the maintenance of polymorphism. Conditions are obtained when this is the case. Finally, the dependence of the phenotypic variance, linkage disequilibrium, and various measures of local adaptation and differentiation on the parameters is elaborated. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Cognitive symptoms facilitatory for diagnoses in neuropsychiatric disorders: executive functions and locus of control.

    Science.gov (United States)

    Archer, Trevor; Kostrzewa, Richard M; Beninger, Richard J; Palomo, Tomas

    2008-10-01

    Cognitive symptoms, considered in conjunction both with their regional brain and biomarkers as well as affective, attributional and neurodevelopmental components, demonstrate ever-increasing complexity to facilitate conceptualization yet, unavoidably, bedevil diagnosis in neuropsychiatry even before considerations of the enigmatic processes in memory, such as executive function and working memory, are drawn into the myriads of equations that await remedial interpretations. Prefrontal and limbic regions of the brain are involved in a diversity of expressions of cognition, normal or dysfunctional, at synaptic, intracellular and molecular levels that mobilize a concatenation of signaling entities. Serotoninergic neurotransission at prefrontal regions directs cognitive-affective entities that mediate decision-making and goal-directed behaviour. Clinical, non-clinical and basic studies challenge attempts to consolidate the multitude of evidence in order to obtain therapeutic notions to alleviate the disordered status of the diagnosed and yet-to-be diagnosed individuals. Locus of control, a concept of some utility in health-seeking procedures, is examined in three self-report studies from the perspective of a cognitive-emotional situation through observations of ordinary, 'healthy' young and middle-aged individuals, to assess the predictors of internal and external locus of control. A notion based on high level executive functioning in the dorsolateral prefrontal cortex (DLPFC) in individuals characterised by internal locus of control is contrasted with a hypofunctional executive DLPFC, characterising individuals that express an external locus of control, is discussed.

  18. Protein quantitative trait locus study in obesity during weight-loss identifies a leptin regulator

    DEFF Research Database (Denmark)

    Carayol, Jérôme; Chabert, Christian; Di Cara, Alessandro

    2017-01-01

    of an organism. Proteome analysis especially can provide new insights into the molecular mechanisms of complex traits like obesity. The role of genetic variation in determining protein level variation has not been assessed in obesity. To address this, we design a large-scale protein quantitative trait locus (p...

  19. Transcriptional regulation of the tad locus in Aggregatibacter actinomycetemcomitans: a termination cascade.

    Science.gov (United States)

    Kram, Karin E; Hovel-Miner, Galadriel A; Tomich, Mladen; Figurski, David H

    2008-06-01

    The tad (tight adherence) locus of Aggregatibacter actinomycetemcomitans includes genes for the biogenesis of Flp pili, which are necessary for bacterial adhesion to surfaces, biofilm formation, and pathogenesis. Although studies have elucidated the functions of some of the Tad proteins, little is known about the regulation of the tad locus in A. actinomycetemcomitans. A promoter upstream of the tad locus was previously identified and shown to function in Escherichia coli. Using a specially constructed reporter plasmid, we show here that this promoter (tadp) functions in A. actinomycetemcomitans. To study expression of the pilin gene (flp-1) relative to that of tad secretion complex genes, we used Northern hybridization analysis and a lacZ reporter assay. We identified three terminators, two of which (T1 and T2) can explain flp-1 mRNA abundance, while the third (T3) is at the end of the locus. T1 and T3 have the appearance and behavior of intrinsic terminators, while T2 has a different structure and is inhibited by bicyclomycin, indicating that T2 is probably Rho dependent. To help achieve the appropriate stoichiometry of the Tad proteins, we show that a transcriptional-termination cascade is important to the proper expression of the tad genes. These data indicate a previously unreported mechanism of regulation in A. actinomycetemcomitans and lead to a more complete understanding of its Flp pilus biogenesis.

  20. The Relationship among Stress, Burnout, and Locus of Control of School Psychologists

    Science.gov (United States)

    Reece, Shana J.

    2010-01-01

    The purpose of this study was to determine how stress, burnout, and locus of control are related for school psychologists providing direct services in the Metropolitan Nashville Public School System. This knowledge is essential in providing the needed experience and outlook of working as a school psychologist. The current study provided school…