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Sample records for chromosome specific allelic

  1. Comparative anatomy of chromosomal domains with imprinted and non-imprinted allele-specific DNA methylation.

    Science.gov (United States)

    Paliwal, Anupam; Temkin, Alexis M; Kerkel, Kristi; Yale, Alexander; Yotova, Iveta; Drost, Natalia; Lax, Simon; Nhan-Chang, Chia-Ling; Powell, Charles; Borczuk, Alain; Aviv, Abraham; Wapner, Ronald; Chen, Xiaowei; Nagy, Peter L; Schork, Nicholas; Do, Catherine; Torkamani, Ali; Tycko, Benjamin

    2013-08-01

    Allele-specific DNA methylation (ASM) is well studied in imprinted domains, but this type of epigenetic asymmetry is actually found more commonly at non-imprinted loci, where the ASM is dictated not by parent-of-origin but instead by the local haplotype. We identified loci with strong ASM in human tissues from methylation-sensitive SNP array data. Two index regions (bisulfite PCR amplicons), one between the C3orf27 and RPN1 genes in chromosome band 3q21 and the other near the VTRNA2-1 vault RNA in band 5q31, proved to be new examples of imprinted DMRs (maternal alleles methylated) while a third, between STEAP3 and C2orf76 in chromosome band 2q14, showed non-imprinted haplotype-dependent ASM. Using long-read bisulfite sequencing (bis-seq) in 8 human tissues we found that in all 3 domains the ASM is restricted to single differentially methylated regions (DMRs), each less than 2kb. The ASM in the C3orf27-RPN1 intergenic region was placenta-specific and associated with allele-specific expression of a long non-coding RNA. Strikingly, the discrete DMRs in all 3 regions overlap with binding sites for the insulator protein CTCF, which we found selectively bound to the unmethylated allele of the STEAP3-C2orf76 DMR. Methylation mapping in two additional genes with non-imprinted haplotype-dependent ASM, ELK3 and CYP2A7, showed that the CYP2A7 DMR also overlaps a CTCF site. Thus, two features of imprinted domains, highly localized DMRs and allele-specific insulator occupancy by CTCF, can also be found in chromosomal domains with non-imprinted ASM. Arguing for biological importance, our analysis of published whole genome bis-seq data from hES cells revealed multiple genome-wide association study (GWAS) peaks near CTCF binding sites with ASM.

  2. Allele-specific marker generation and linkage mapping on the Xiphophorus sex chromosomes.

    Science.gov (United States)

    Woolcock, B; Kazianis, S; Lucito, R; Walter, R B; Kallman, K D; Morizot, D C; Vielkind, J R

    2006-01-01

    There is great interest in the sex chromosomes of Xiphophorus fishes because both WY/YY and XX/XY sex-determining mechanisms function in these species, with at least one taxon possessing all three types of sex chromosomes, and because in certain interspecific hybrids melanoma arises as a consequence of inheritance of the sex-linked macromelanophore determining locus (MDL). Representational difference analysis (RDA) has been used to clone two sequences from the sex-determining region of X. maculatus, including a cholinergic receptor, nicotinic, delta polypeptide (CHRND) orthologue. Allele-specific assays for these sequences, as well as for the sex-linked XMRK1 and XMRK2 genes, were developed to distinguish W, X, and Y chromosomes derived from a X. maculatus (XX/XY) strain and a X. helleri (WY/YY) strain. Linkage mapping localized these markers to linkage group (LG) 24. No recombinants were observed between XMRK2 and MDL, confirming a role for XMRK2 in macromelanophore development. Although the master sex-determining (SD) locus certainly resides on Xiphophorus LG 24, autosomal loci are probably involved in sex determination as well, as indicated by the abnormal sex ratios in the backcross hybrids that contrast theoretical predictions based on LG 24 genotyping. Marker development and allelic discrimination on the Xiphophorus sex chromosomes should prove highly useful for studies that utilize this genus as an animal model.

  3. Comparative anatomy of chromosomal domains with imprinted and non-imprinted allele-specific DNA methylation.

    Directory of Open Access Journals (Sweden)

    Anupam Paliwal

    2013-08-01

    Full Text Available Allele-specific DNA methylation (ASM is well studied in imprinted domains, but this type of epigenetic asymmetry is actually found more commonly at non-imprinted loci, where the ASM is dictated not by parent-of-origin but instead by the local haplotype. We identified loci with strong ASM in human tissues from methylation-sensitive SNP array data. Two index regions (bisulfite PCR amplicons, one between the C3orf27 and RPN1 genes in chromosome band 3q21 and the other near the VTRNA2-1 vault RNA in band 5q31, proved to be new examples of imprinted DMRs (maternal alleles methylated while a third, between STEAP3 and C2orf76 in chromosome band 2q14, showed non-imprinted haplotype-dependent ASM. Using long-read bisulfite sequencing (bis-seq in 8 human tissues we found that in all 3 domains the ASM is restricted to single differentially methylated regions (DMRs, each less than 2kb. The ASM in the C3orf27-RPN1 intergenic region was placenta-specific and associated with allele-specific expression of a long non-coding RNA. Strikingly, the discrete DMRs in all 3 regions overlap with binding sites for the insulator protein CTCF, which we found selectively bound to the unmethylated allele of the STEAP3-C2orf76 DMR. Methylation mapping in two additional genes with non-imprinted haplotype-dependent ASM, ELK3 and CYP2A7, showed that the CYP2A7 DMR also overlaps a CTCF site. Thus, two features of imprinted domains, highly localized DMRs and allele-specific insulator occupancy by CTCF, can also be found in chromosomal domains with non-imprinted ASM. Arguing for biological importance, our analysis of published whole genome bis-seq data from hES cells revealed multiple genome-wide association study (GWAS peaks near CTCF binding sites with ASM.

  4. The probability to initiate X chromosome inactivation is determined by the X to autosomal ratio and X chromosome specific allelic properties.

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    Kim Monkhorst

    Full Text Available In female mammalian cells, random X chromosome inactivation (XCI equalizes the dosage of X-encoded gene products to that in male cells. XCI is a stochastic process, in which each X chromosome has a probability to be inactivated. To obtain more insight in the factors setting up this probability, we studied the role of the X to autosome (X ratio A ratio in initiation of XCI, and have used the experimental data in a computer simulation model to study the cellular population dynamics of XCI.To obtain more insight in the role of the XratioA ratio in initiation of XCI, we generated triploid mouse ES cells by fusion of haploid round spermatids with diploid female and male ES cells. These fusion experiments resulted in only XXY triploid ES cells. XYY and XXX ES lines were absent, suggesting cell death related either to insufficient X-chromosomal gene dosage (XYY or to inheritance of an epigenetically modified X chromosome (XXX. Analysis of active (Xa and inactive (Xi X chromosomes in the obtained triploid XXY lines indicated that the initiation frequency of XCI is low, resulting in a mixed population of XaXiY and XaXaY cells, in which the XaXiY cells have a small proliferative advantage. This result, and findings on XCI in diploid and tetraploid ES cell lines with different X ratio A ratios, provides evidence that the X ratio A ratio determines the probability for a given X chromosome to be inactivated. Furthermore, we found that the kinetics of the XCI process can be simulated using a probability for an X chromosome to be inactivated that is proportional to the X ratio A ratio. These simulation studies re-emphasize our hypothesis that the probability is a function of the concentration of an X-encoded activator of XCI, and of X chromosome specific allelic properties determining the threshold for this activator.The present findings reveal that the probability for an X chromosome to be inactivated is proportional to the X ratio A ratio. This finding

  5. Genetic mapping of a new race specific resistance allele effective to Puccinia hordei at the Rph9/Rph12 locus on chromosome 5HL in barley.

    Science.gov (United States)

    Dracatos, Peter M; Khatkar, Mehar S; Singh, Davinder; Park, Robert F

    2014-12-20

    Barley is an important cereal crop cultivated for malt and ruminant feed and in certain regions it is used for human consumption. It is vulnerable to numerous foliar diseases including barley leaf rust caused by the pathogen Puccinia hordei. A temporarily designated resistance locus RphCantala (RphC) identified in the Australian Hordeum vulgare L. cultivar 'Cantala' displayed an intermediate to low infection type (";12 = N") against the P. hordei pathotype 253P- (virulent on Rph1, Rph2, Rph4, Rph6, Rph8 and RphQ). Phenotypic assessment of a 'CI 9214' (susceptible) x 'Stirling' (RphC) (CI 9214/Stirling) doubled haploid (DH) population at the seedling stage using P. hordei pathotype 253P-, confirmed that RphC was monogenically inherited. Marker-trait association analysis of RphC in the CI 9214/Stirling DH population using 4,500 DArT-seq markers identified a highly significant (-log10Pvalue > 17) single peak on the long arm of chromosome 5H (5HL). Further tests of allelism determined that RphC was genetically independent of Rph3, Rph7, Rph11, Rph13 and Rph14, and was an allele of Rph12 (Rph9.z), which also maps to 5HL. Multipathotype tests and subsequent pedigree analysis determined that 14 related Australian barley varieties (including 'Stirling' and 'Cantala') carry RphC and that the likely source of this resistance is via a Czechoslovakian landrace LV-Kvasice-NA-Morave transferred through common ancestral cultivars 'Hanna' and 'Abed Binder'. RphC is an allele of Rph12 (Rph9.z) and is therefore designated Rph9.am. Bioinformatic analysis using sequence arrays from DArT-seq markers in linkage disequilibrium with Rph9.am identified possible candidates for further gene cloning efforts and marker development at the Rph9/Rph12/Rph9.am locus.

  6. Vibrio chromosome-specific families

    DEFF Research Database (Denmark)

    Lukjancenko, Oksana; Ussery, David

    2014-01-01

    We have compared chromosome-specific genes in a set of 18 finished Vibrio genomes, and, in addition, also calculated the pan- and core-genomes from a data set of more than 250 draft Vibrio genome sequences. These genomes come from 9 known species and 2 unknown species. Within the finished...... chromosomes, we find a core set of 1269 encoded protein families for chromosome 1, and a core of 252 encoded protein families for chromosome 2. Many of these core proteins are also found in the draft genomes (although which chromosome they are located on is unknown.) Of the chromosome specific core protein...... families, 1169 and 153 are uniquely found in chromosomes 1 and 2, respectively. Gene ontology (GO) terms for each of the protein families were determined, and the different sets for each chromosome were compared. A total of 363 different "Molecular Function" GO categories were found for chromosome 1...

  7. A common allele on chromosome 9 associated with coronary heartdisease

    Energy Technology Data Exchange (ETDEWEB)

    McPherson, Ruth; Pertsemlidis, Alexander; Kavaslar, Nihan; Stewart, Alexandre; Roberts, Robert; Cox, David R.; Hinds, David; Pennachio, Len; Tybjaerg-Hansen, Anne; Folsom, Aaron R.; Boerwinkle,Eric; Hobbs, Helen H.; Cohen, Jonathan C.

    2007-03-01

    Coronary heart disease (CHD) is a major cause of death in Western countries. Here we used genome-wide association scanning to identify a 58 kb interval on chromosome 9 that was consistently associated with CHD in six independent samples. The interval contains no annotated genes and is not associated with established CHD risk factors such as plasma lipoproteins, hypertension or diabetes. Homozygotes for the risk allele comprise 20-25% of Caucasians and have a {approx}30-40% increased risk of CHD. These data indicate that the susceptibility allele acts through a novel mechanism to increase CHD risk in a large fraction of the population.

  8. Delimiting Allelic Imbalance of TYMS by Allele-Specific Analysis.

    Science.gov (United States)

    Balboa-Beltrán, Emilia; Cruz, Raquel; Carracedo, Angel; Barros, Francisco

    2015-07-01

    Allelic imbalance of thymidylate synthase (TYMS) is attributed to polymorphisms in the 5'- and 3'-untranslated region (UTR). These polymorphisms have been related to the risk of suffering different cancers, for example leukemia, breast or gastric cancer, and response to different drugs, among which are methotrexate glutamates, stavudine, and specifically 5-fluorouracil (5-FU), as TYMS is its direct target. A vast literature has been published in relation to 5-FU, even suggesting the sole use of these polymorphisms to effectively manage 5-FU dosage. Estimates of the extent to which these polymorphisms influence in TYMS expression have in the past been based on functional analysis by luciferase assays and quantification of TYMS mRNA, but both these studies, as the association studies with cancer risk or with toxicity or response to 5-FU, are very contradictory. Regarding functional assays, the artificial genetic environment created in luciferase assay and the problems derived from quantitative polymerase chain reactions (qPCRs), for example the use of a reference gene, may have distorted the results. To avoid these sources of interference, we have analyzed the allelic imbalance of TYMS by allelic-specific analysis in peripheral blood mononuclear cells (PBMCs) from patients.Allelic imbalance in PBMCs, taken from 40 patients with suspected myeloproliferative haematological diseases, was determined by fluorescent fragment analysis (for the 3'-UTR polymorphism), Sanger sequencing and allelic-specific qPCR in multiplex (for the 5'-UTR polymorphisms).For neither the 3'- nor the 5'-UTR polymorphisms did the observed allelic imbalance exceed 1.5 fold. None of the TYMS polymorphisms is statistically associated with allelic imbalance.The results acquired allow us to deny the previously established assertion of an influence of 2 to 4 fold of the rs45445694 and rs2853542 polymorphisms in the expression of TYMS and narrow its allelic imbalance to 1.5 fold, in our population

  9. A donor-specific QTL, exhibiting allelic variation for leaf sheath hairiness in a nested association mapping population, is located on barley chromosome 4H

    KAUST Repository

    Saade, Stephanie; Kutlu, Burcu; Draba, Vera; Fö rster, Karin; Schumann, Erika; Tester, Mark A.; Pillen, Klaus; Maurer, Andreas

    2017-01-01

    Leaf sheath hairiness is a morphological trait associated with various advantages, including tolerance to both abiotic and biotic stresses, thereby increasing yield. Understanding the genetic basis of this trait in barley can therefore improve the agronomic performance of this economically important crop. We scored leaf sheath hairiness in a two-year field trial in 1,420 BC1S3 lines from the wild barley nested association mapping (NAM) population HEB-25. Leaf sheath hairiness segregated in six out of 25 families with the reference parent Barke being glabrous. We detected the major hairy leaf sheath locus Hs (syn. Hsh) on chromosome 4H (111.3 cM) with high precision. The effects of the locus varied across the six different wild barley donors, with donor of HEB family 11 conferring the highest score of leaf sheath hairiness. Due to the high mapping resolution present in HEB-25, we were able to discuss physically linked pentatricopeptide repeat genes and subtilisin-like proteases as potential candidate genes underlying this locus. In this study, we proved that HEB-25 provides an appropriate tool to further understand the genetic control of leaf sheath hairiness in barley. Furthermore, our work represents a perfect starting position to clone the gene responsible for the 4H locus observed.

  10. A donor-specific QTL, exhibiting allelic variation for leaf sheath hairiness in a nested association mapping population, is located on barley chromosome 4H

    KAUST Repository

    Saade, Stephanie

    2017-12-07

    Leaf sheath hairiness is a morphological trait associated with various advantages, including tolerance to both abiotic and biotic stresses, thereby increasing yield. Understanding the genetic basis of this trait in barley can therefore improve the agronomic performance of this economically important crop. We scored leaf sheath hairiness in a two-year field trial in 1,420 BC1S3 lines from the wild barley nested association mapping (NAM) population HEB-25. Leaf sheath hairiness segregated in six out of 25 families with the reference parent Barke being glabrous. We detected the major hairy leaf sheath locus Hs (syn. Hsh) on chromosome 4H (111.3 cM) with high precision. The effects of the locus varied across the six different wild barley donors, with donor of HEB family 11 conferring the highest score of leaf sheath hairiness. Due to the high mapping resolution present in HEB-25, we were able to discuss physically linked pentatricopeptide repeat genes and subtilisin-like proteases as potential candidate genes underlying this locus. In this study, we proved that HEB-25 provides an appropriate tool to further understand the genetic control of leaf sheath hairiness in barley. Furthermore, our work represents a perfect starting position to clone the gene responsible for the 4H locus observed.

  11. Allele specific expression and methylation in the bumblebee, Bombus terrestris

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    Zoë Lonsdale

    2017-09-01

    Full Text Available The social hymenoptera are emerging as models for epigenetics. DNA methylation, the addition of a methyl group, is a common epigenetic marker. In mammals and flowering plants methylation affects allele specific expression. There is contradictory evidence for the role of methylation on allele specific expression in social insects. The aim of this paper is to investigate allele specific expression and monoallelic methylation in the bumblebee, Bombus terrestris. We found nineteen genes that were both monoallelically methylated and monoallelically expressed in a single bee. Fourteen of these genes express the hypermethylated allele, while the other five express the hypomethylated allele. We also searched for allele specific expression in twenty-nine published RNA-seq libraries. We found 555 loci with allele-specific expression. We discuss our results with reference to the functional role of methylation in gene expression in insects and in the as yet unquantified role of genetic cis effects in insect allele specific methylation and expression.

  12. Pure chromosome-specific PCR libraries from single sorted chromosomes

    NARCIS (Netherlands)

    VanDevanter, D. R.; Choongkittaworn, N. M.; Dyer, K. A.; Aten, J. A.; Otto, P.; Behler, C.; Bryant, E. M.; Rabinovitch, P. S.

    1994-01-01

    Chromosome-specific DNA libraries can be very useful in molecular and cytogenetic genome mapping studies. We have developed a rapid and simple method for the generation of chromosome-specific DNA sequences that relies on polymerase chain reaction (PCR) amplification of a single flow-sorted

  13. Allele Workbench: transcriptome pipeline and interactive graphics for allele-specific expression.

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    Carol A Soderlund

    Full Text Available Sequencing the transcriptome can answer various questions such as determining the transcripts expressed in a given species for a specific tissue or condition, evaluating differential expression, discovering variants, and evaluating allele-specific expression. Differential expression evaluates the expression differences between different strains, tissues, and conditions. Allele-specific expression evaluates expression differences between parental alleles. Both differential expression and allele-specific expression have been studied for heterosis (hybrid vigor, where the hybrid has improved performance over the parents for one or more traits. The Allele Workbench software was developed for a heterosis study that evaluated allele-specific expression for a mouse F1 hybrid using libraries from multiple tissues with biological replicates. This software has been made into a distributable package, which includes a pipeline, a Java interface to build the database, and a Java interface for query and display of the results. The required input is a reference genome, annotation file, and one or more RNA-Seq libraries with optional replicates. It evaluates allelic imbalance at the SNP and transcript level and flags transcripts with significant opposite directional allele-specific expression. The Java interface allows the user to view data from libraries, replicates, genes, transcripts, exons, and variants, including queries on allele imbalance for selected libraries. To determine the impact of allele-specific SNPs on protein folding, variants are annotated with their effect (e.g., missense, and the parental protein sequences may be exported for protein folding analysis. The Allele Workbench processing results in transcript files and read counts that can be used as input to the previously published Transcriptome Computational Workbench, which has a new algorithm for determining a trimmed set of gene ontology terms. The software with demo files is available

  14. The fate of chromosomes and alleles in an allohexaploid Brassica population.

    Science.gov (United States)

    Mason, Annaliese S; Nelson, Matthew N; Takahira, Junko; Cowling, Wallace A; Alves, Gustavo Moreira; Chaudhuri, Arkaprava; Chen, Ning; Ragu, Mohana E; Dalton-Morgan, Jessica; Coriton, Olivier; Huteau, Virginie; Eber, Frédérique; Chèvre, Anne-Marie; Batley, Jacqueline

    2014-05-01

    Production of allohexaploid Brassica (2n = AABBCC) is a promising goal for plant breeders due to the potential for hybrid heterosis and useful allelic contributions from all three of the Brassica genomes present in the cultivated diploid (2n = AA, 2n = BB, 2n = CC) and allotetraploid (2n = AABB, 2n = AACC, and 2n = BBCC) crop species (canola, cabbages, mustards). We used high-throughput SNP molecular marker assays, flow cytometry, and fluorescent in situ hybridization (FISH) to characterize a population of putative allohexaploids derived from self-pollination of a hybrid from the novel cross (B. napus × B. carinata) × B. juncea to investigate whether fertile, stable allohexaploid Brassica can be produced. Allelic segregation in the A and C genomes generally followed Mendelian expectations for an F2 population, with minimal nonhomologous chromosome pairing. However, we detected no strong selection for complete 2n = AABBCC chromosome complements, with weak correlations between DNA content and fertility (r(2) = 0.11) and no correlation between missing chromosomes or chromosome segments and fertility. Investigation of next-generation progeny resulting from one highly fertile F2 plant using FISH revealed general maintenance of high chromosome numbers but severe distortions in karyotype, as evidenced by recombinant chromosomes and putative loss/duplication of A- and C-genome chromosome pairs. Our results show promise for the development of meiotically stable allohexaploid lines, but highlight the necessity of selection for 2n = AABBCC karyotypes.

  15. Allele-specific physical interactions regulate the heterotic traits in hybrids of Arabidopsis thaliana ecotypes

    Directory of Open Access Journals (Sweden)

    Babita Singh

    2017-10-01

    Full Text Available Heterosis is an important phenomenon for the breeding in agricultural crops as it influences yield related traits such as biomass yield, seed number and weight, adaptive and reproductive traits. However, the level of heterosis greatly varies for different traits and different genotypes. The present study focuses on identification of physical interactions between alleles and their role in transcriptional regulation in heterotic plants. Here, we used two Arabidopsis ecotypes; Col-0 and C24 as parent for crosses. We performed crossing between these ecotypes and screened the F1 hybrids on the basis of different SSR markers. Further, we used Hi-C to capture intra- and inter-chromosomal physical interactions between alleles on genome-wide level. Then, we identified allele-specific chromatin interactions and constructed genome-wide allele-specific contact maps at different resolutions for the entire chromosome. We also performed RNA-seq of hybrids and their parents. RNA-seq analysis identified several differentially expressed genes and non-additively expressed genes in hybrids with respect to their parents. Further, to understand the biological significance of these chromatin interactions, we annotated these interactions and correlated with the transcriptome data. Thus, our study provides alleles-specific chromatin interactions in genome-wide fashion which play a crucial role in regulation of different genes that may be important for heterosis.

  16. Screening for SNPs with Allele-Specific Methylation based on Next-Generation Sequencing Data

    OpenAIRE

    Hu, Bo; Ji, Yuan; Xu, Yaomin; Ting, Angela H

    2013-01-01

    Allele-specific methylation (ASM) has long been studied but mainly documented in the context of genomic imprinting and X chromosome inactivation. Taking advantage of the next-generation sequencing technology, we conduct a high-throughput sequencing experiment with four prostate cell lines to survey the whole genome and identify single nucleotide polymorphisms (SNPs) with ASM. A Bayesian approach is proposed to model the counts of short reads for each SNP conditional on its genotypes of multip...

  17. ALEA: a toolbox for allele-specific epigenomics analysis.

    Science.gov (United States)

    Younesy, Hamid; Möller, Torsten; Heravi-Moussavi, Alireza; Cheng, Jeffrey B; Costello, Joseph F; Lorincz, Matthew C; Karimi, Mohammad M; Jones, Steven J M

    2014-04-15

    The assessment of expression and epigenomic status using sequencing based methods provides an unprecedented opportunity to identify and correlate allelic differences with epigenomic status. We present ALEA, a computational toolbox for allele-specific epigenomics analysis, which incorporates allelic variation data within existing resources, allowing for the identification of significant associations between epigenetic modifications and specific allelic variants in human and mouse cells. ALEA provides a customizable pipeline of command line tools for allele-specific analysis of next-generation sequencing data (ChIP-seq, RNA-seq, etc.) that takes the raw sequencing data and produces separate allelic tracks ready to be viewed on genome browsers. The pipeline has been validated using human and hybrid mouse ChIP-seq and RNA-seq data. The package, test data and usage instructions are available online at http://www.bcgsc.ca/platform/bioinfo/software/alea CONTACT: : mkarimi1@interchange.ubc.ca or sjones@bcgsc.ca Supplementary information: Supplementary data are available at Bioinformatics online. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  18. Allele-specific MMP-3 transcription under in vivo conditions

    Energy Technology Data Exchange (ETDEWEB)

    Chaoyong, Zhu [Atherosclerosis Research Unit, King Gustav V Research Institute, Department of Medicine, Karolinska Institute, Stockholm (Sweden); Odeberg, Jacob [Atherosclerosis Research Unit, King Gustav V Research Institute, Department of Medicine, Karolinska Institute, Stockholm (Sweden); Department of Biotechnology, AlbaNova University Center, Royal Institute of Technology, Stockholm (Sweden); Hamsten, Anders [Atherosclerosis Research Unit, King Gustav V Research Institute, Department of Medicine, Karolinska Institute, Stockholm (Sweden); Eriksson, Per [Atherosclerosis Research Unit, King Gustav V Research Institute, Department of Medicine, Karolinska Institute, Stockholm (Sweden)

    2006-09-29

    A common matrix metalloproteinases-3 (MMP-3) -1612 5A/6A promoter polymorphism is associated with risk for cardiovascular disease, rheumatoid arthritis, and other diseases. Here we used the haplotype chromatin immunoprecipitation method to study allele-specific MMP-3 expression under in vivo conditions in heterozygous THP-1 cells. Pyrosequencing was used to analyse the ratio of 5A-allele to 6A-allele after chromatin immunoprecipitation using an antibody against phosphorylated active RNA polymerase II. There was no allele-specific difference in transcriptional activity during basal conditions, i.e., in unstimulated monocytic THP-1 cells. However, after stimulation of MMP-3 expression by monocyte differentiation or incubation with IL-1{beta}, the haplotype containing the 5A-allele was associated with higher transcriptional activity compared with the 6A-containing haplotype. Electromobility shift assay demonstrated increased binding of nuclear proteins to the 5A-allele after monocyte differentiation. In conclusion, the common MMP-3 5A/6A promoter polymorphism appears to be functional only during specific environmental conditions involving inflammation.

  19. Allele-specific deletions in mouse tumors identify Fbxw7 as germline modifier of tumor susceptibility.

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    Jesus Perez-Losada

    Full Text Available Genome-wide association studies (GWAS have been successful in finding associations between specific genetic variants and cancer susceptibility in human populations. These studies have identified a range of highly statistically significant associations between single nucleotide polymorphisms (SNPs and susceptibility to development of a range of human tumors. However, the effect of each SNP in isolation is very small, and all of the SNPs combined only account for a relatively minor proportion of the total genetic risk (5-10%. There is therefore a major requirement for alternative routes to the discovery of genetic risk factors for cancer. We have previously shown using mouse models that chromosomal regions harboring susceptibility genes identified by linkage analysis frequently exhibit allele-specific genetic alterations in tumors. We demonstrate here that the Fbxw7 gene, a commonly mutated gene in a wide range of mouse and human cancers, shows allele-specific deletions in mouse lymphomas and skin tumors. Lymphomas from three different F1 hybrids show 100% allele-specificity in the patterns of allelic loss. Parental alleles from 129/Sv or Spretus/Gla mice are lost in tumors from F1 hybrids with C57BL/6 animals, due to the presence of a specific non-synonymous coding sequence polymorphism at the N-terminal portion of the gene. A specific genetic test of association between this SNP and lymphoma susceptibility in interspecific backcross mice showed a significant linkage (p = 0.001, but only in animals with a functional p53 gene. These data therefore identify Fbxw7 as a p53-dependent tumor susceptibility gene. Increased p53-dependent tumor susceptibility and allele-specific losses were also seen in a mouse skin model of skin tumor development. We propose that analysis of preferential allelic imbalances in tumors may provide an efficient means of uncovering genetic variants that affect mouse and human tumor susceptibility.

  20. Chromosome-specific DNA Repeat Probes

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    Baumgartner, Adolf; Weier, Jingly Fung; Weier, Heinz-Ulrich G.

    2006-03-16

    In research as well as in clinical applications, fluorescence in situ hybridization (FISH) has gained increasing popularity as a highly sensitive technique to study cytogenetic changes. Today, hundreds of commercially available DNA probes serve the basic needs of the biomedical research community. Widespread applications, however, are often limited by the lack of appropriately labeled, specific nucleic acid probes. We describe two approaches for an expeditious preparation of chromosome-specific DNAs and the subsequent probe labeling with reporter molecules of choice. The described techniques allow the preparation of highly specific DNA repeat probes suitable for enumeration of chromosomes in interphase cell nuclei or tissue sections. In addition, there is no need for chromosome enrichment by flow cytometry and sorting or molecular cloning. Our PCR-based method uses either bacterial artificial chromosomes or human genomic DNA as templates with {alpha}-satellite-specific primers. Here we demonstrate the production of fluorochrome-labeled DNA repeat probes specific for human chromosomes 17 and 18 in just a few days without the need for highly specialized equipment and without the limitation to only a few fluorochrome labels.

  1. Allelic imbalance on chromosome 1 in human breast cancer. I. Minisatellite and RFLP analysis.

    Science.gov (United States)

    Loupart, M L; Armour, J; Walker, R; Adams, S; Brammar, W; Varley, J

    1995-01-01

    In order to characterise the role of chromosome 1 more fully in breast cancer, polymorphic markers mapping along the length of the whole chromosome were used to assess a panel of 71 tumour-lymphocyte pairs for allelic imbalance. Complex patterns of alterations were established that are consistent with cytogenetic data in the literature. Deletion mapping of individuals with loss of heterozygosity identified five independent smallest common regions of deletion, two of which are novel. There are also three discrete regions showing a gain in copy number of one homologue. The two arms of the chromosome may be subject to different events; the short arm primarily undergoes interstitial deletions, whereas the long arm is subject to whole arm events (as both gains and losses) as well as regional deletions.

  2. Allele-specific expression in the germline of patients with familial pancreatic cancer: An unbiased approach to cancer gene discovery

    OpenAIRE

    Tan, Aik Choon; Fan, Jian-Bing; Karikari, Collins; Bibikova, Marina; Garcia, Eliza Wickham; Zhou, Lixin; Barker, David; Serre, David; Feldmann, Georg; Hruban, Ralph H.; Klein, Alison P.; Goggins, Michael; Couch, Fergus J.; Hudson, Thomas J.; Winslow, Raimond L.

    2007-01-01

    Physiologic allele-specific expression (ASE) in germline tissues occurs during random X-chromosome inactivation1 and in genomic imprinting,2 wherein the two alleles of a gene in a heterozygous individual are not expressed equally. Recent studies have confirmed the existence of ASE in apparently non-imprinted autosomal genes;3–14 however, the extent of ASE in the human genome is unknown. We explored ASE in lymphoblastoid cell lines of 145 individuals using an oligonucleotide array based assay....

  3. Dominant hemimelia and En-1 on mouse chromosome 1 are not allelic.

    Science.gov (United States)

    Higgins, M; Hill, R E; West, J D

    1992-08-01

    Previous studies have shown that En-1, a homeobox-containing gene, maps close to or at the Dh locus in the mouse. Since homeobox-containing genes are key genes in the control of development the close proximity of En-1 to the developmentally significant gene Dh raised the possibility that the Dh mutation represented a mutant allele of En-1. A genetic analysis involving En-1, Dh, and other chromosome 1 markers (Emv-17, ln and Pep-3) shows that although Dh and En-1 are closely linked they are separable by recombination (4/563). The likely gene order and recombination frequencies of these loci are: ln (5.2 +/- 0.9) Emv-17 (1.1 +/- 0.4) Dh (0.7 +/- 0.4) En-1 (3.0 +/- 0.7) Pep-3. This shows that Dh is not a mutant allele of En-1.

  4. Allele-Specific DNA Methylation Detection by Pyrosequencing®

    DEFF Research Database (Denmark)

    Kristensen, Lasse Sommer; Johansen, Jens Vilstrup; Grønbæk, Kirsten

    2015-01-01

    DNA methylation is an epigenetic modification that plays important roles in healthy as well as diseased cells, by influencing the transcription of genes. In spite the fact that human somatic cells are diploid, most of the currently available methods for the study of DNA methylation do not provide......-effective protocol for allele-specific DNA methylation detection based on Pyrosequencing(®) of methylation-specific PCR (MSP) products including a single nucleotide polymorphism (SNP) within the amplicon....

  5. Slit scan flow cytometry of isolated chromosomes following fluorescence hybridization: an approach of online screening for specific chromosomes and chromosome translocations

    NARCIS (Netherlands)

    Hausmann, M.; Dudin, G.; Aten, J. A.; Heilig, R.; Diaz, E.; Cremer, C.

    1991-01-01

    The recently developed methods of non radioactive in situ hybridization of chromosomes offer new aspects for chromosome analysis. Fluorescent labelling of hybridized chromosomes or chromosomal subregions allows to facilitate considerably the detection of specific chromosomal abnormalities. For many

  6. QuASAR: quantitative allele-specific analysis of reads.

    Science.gov (United States)

    Harvey, Chris T; Moyerbrailean, Gregory A; Davis, Gordon O; Wen, Xiaoquan; Luca, Francesca; Pique-Regi, Roger

    2015-04-15

    Expression quantitative trait loci (eQTL) studies have discovered thousands of genetic variants that regulate gene expression, enabling a better understanding of the functional role of non-coding sequences. However, eQTL studies are costly, requiring large sample sizes and genome-wide genotyping of each sample. In contrast, analysis of allele-specific expression (ASE) is becoming a popular approach to detect the effect of genetic variation on gene expression, even within a single individual. This is typically achieved by counting the number of RNA-seq reads matching each allele at heterozygous sites and testing the null hypothesis of a 1:1 allelic ratio. In principle, when genotype information is not readily available, it could be inferred from the RNA-seq reads directly. However, there are currently no existing methods that jointly infer genotypes and conduct ASE inference, while considering uncertainty in the genotype calls. We present QuASAR, quantitative allele-specific analysis of reads, a novel statistical learning method for jointly detecting heterozygous genotypes and inferring ASE. The proposed ASE inference step takes into consideration the uncertainty in the genotype calls, while including parameters that model base-call errors in sequencing and allelic over-dispersion. We validated our method with experimental data for which high-quality genotypes are available. Results for an additional dataset with multiple replicates at different sequencing depths demonstrate that QuASAR is a powerful tool for ASE analysis when genotypes are not available. http://github.com/piquelab/QuASAR. fluca@wayne.edu or rpique@wayne.edu Supplementary Material is available at Bioinformatics online. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  7. An X-linked Myh11-CreERT2 mouse line resulting from Y to X chromosome-translocation of the Cre allele.

    Science.gov (United States)

    Liao, Mingmei; Zhou, Junmei; Wang, Fen; Ali, Yasmin H; Chan, Kelvin L; Zou, Fei; Offermanns, Stefan; Jiang, Zhisheng; Jiang, Zhihua

    2017-09-01

    The Myh11-CreER T2 mouse line (Cre + ) has gained increasing application because of its high lineage specificity relative to other Cre drivers targeting smooth muscle cells (SMCs). This Cre allele, however, was initially inserted into the Y chromosome (X/Y Cre+ ), which excluded its application in female mice. Our group established a Cre + colony from male ancestors. Surprisingly, genotype screening identified female carriers that stably transmitted the Cre allele to the following generations. Crossbreeding experiments revealed a pattern of X-linked inheritance for the transgene (k > 1000), indicating that these female carries acquired the Cre allele through a mechanism of Y to X chromosome translocation. Further characterization demonstrated that in hemizygous X/X Cre+ mice Cre activity was restricted to a subset arterial SMCs, with Cre expression in arteries decreased by 50% compared to X/Y Cre+ mice. This mosaicism, however, diminished in homozygous X Cre+ /X Cre+ mice. In a model of aortic aneurysm induced by a SMC-specific Tgfbr1 deletion, the homozygous X Cre+ /X Cre+ Cre driver unmasked the aortic phenotype that is otherwise subclinical when driven by the hemizygous X/X Cre+ Cre line. In conclusion, the Cre allele carried by this female mouse line is located on the X chromosome and subjected to X-inactivation. The homozygous X Cre+ /X Cre+ mice produce uniform Cre activity in arterial SMCs. © 2017 Wiley Periodicals, Inc.

  8. Identification of internal variation in the pseudoautosomal VNTR DXYS17, with nonrandom distribution of the alleles on the X and the Y chromosomes

    Energy Technology Data Exchange (ETDEWEB)

    Decorte, R.; Wu, R.; Marynen, P.; Cassiman, J.J.

    1994-03-01

    The PCR technique was used to analyze the DXYS17 locus in the pseudoautosomal region of the X and the Y chromosomes. Analysis on an automated DNA sequencer allowed for sensitive and highly accurate typing of 16 different alleles with a size between 480 and 1,100 bp. Two DXYS17 alleles migrated with the same size on agarose or denaturing polyacrylamide gels but with different mobilities on nondenaturing polyacrylamide gels. Sequence analysis showed that, while an identical number of repeats were present in both alleles, differences in the composition of the units were observed. The origin of these differences was found in the 28- and 33-bp units, which only had a specific repeat pattern at the 5' and 3' ends of the region. The genotype distribution for DXYS17 in a Caucasian population did not deviate from the values expected under Hardy-Weinberg equilibrium. However, the frequency of one allele and one genotype was significantly different between males and females. Segregation analysis showed that this difference was the result of a nonrandom distribution of certain alleles on the sex chromosomes in males. 31 refs., 4 figs., 2 tabs.

  9. Exchange of core chromosomes and horizontal transfer of lineage-specific chromosomes in Fusarium oxysporum

    NARCIS (Netherlands)

    Vlaardingerbroek, I.; Beerens, B.; Rose, L.; Fokkens, L.; Cornelissen, B.J.C.; Rep, M.

    2016-01-01

    Horizontal transfer of supernumerary or lineage-specific (LS) chromosomes has been described in a number of plant pathogenic filamentous fungi. So far it was not known whether transfer is restricted to chromosomes of certain size or properties, or whether 'core' chromosomes can also undergo

  10. Allelic Imbalance Is a Prevalent and Tissue-Specific Feature of the Mouse Transcriptome

    Science.gov (United States)

    Pinter, Stefan F.; Colognori, David; Beliveau, Brian J.; Sadreyev, Ruslan I.; Payer, Bernhard; Yildirim, Eda; Wu, Chao-ting; Lee, Jeannie T.

    2015-01-01

    In mammals, several classes of monoallelic genes have been identified, including those subject to X-chromosome inactivation (XCI), genomic imprinting, and random monoallelic expression (RMAE). However, the extent to which these epigenetic phenomena are influenced by underlying genetic variation is unknown. Here we perform a systematic classification of allelic imbalance in mouse hybrids derived from reciprocal crosses of divergent strains. We observe that deviation from balanced biallelic expression is common, occurring in ∼20% of the mouse transcriptome in a given tissue. Allelic imbalance attributed to genotypic variation is by far the most prevalent class and typically is tissue-specific. However, some genotype-based imbalance is maintained across tissues and is associated with greater genetic variation, especially in 5′ and 3′ termini of transcripts. We further identify novel random monoallelic and imprinted genes and find that genotype can modify penetrance of parental origin even in the setting of large imprinted regions. Examination of nascent transcripts in single cells from inbred parental strains reveals that genes showing genotype-based imbalance in hybrids can also exhibit monoallelic expression in isogenic backgrounds. This surprising observation may suggest a competition between alleles and/or reflect the combined impact of cis- and trans-acting variation on expression of a given gene. Our findings provide novel insights into gene regulation and may be relevant to human genetic variation and disease. PMID:25858912

  11. A dominantly acting murine allele of Mcm4 causes chromosomal abnormalities and promotes tumorigenesis.

    Directory of Open Access Journals (Sweden)

    Bruce N Bagley

    Full Text Available Here we report the isolation of a murine model for heritable T cell lymphoblastic leukemia/lymphoma (T-ALL called Spontaneous dominant leukemia (Sdl. Sdl heterozygous mice develop disease with a short latency and high penetrance, while mice homozygous for the mutation die early during embryonic development. Sdl mice exhibit an increase in the frequency of micronucleated reticulocytes, and T-ALLs from Sdl mice harbor small amplifications and deletions, including activating deletions at the Notch1 locus. Using exome sequencing it was determined that Sdl mice harbor a spontaneously acquired mutation in Mcm4 (Mcm4(D573H. MCM4 is part of the heterohexameric complex of MCM2-7 that is important for licensing of DNA origins prior to S phase and also serves as the core of the replicative helicase that unwinds DNA at replication forks. Previous studies in murine models have discovered that genetic reductions of MCM complex levels promote tumor formation by causing genomic instability. However, Sdl mice possess normal levels of Mcms, and there is no evidence for loss-of-heterozygosity at the Mcm4 locus in Sdl leukemias. Studies in Saccharomyces cerevisiae indicate that the Sdl mutation produces a biologically inactive helicase. Together, these data support a model in which chromosomal abnormalities in Sdl mice result from the ability of MCM4(D573H to incorporate into MCM complexes and render them inactive. Our studies indicate that dominantly acting alleles of MCMs can be compatible with viability but have dramatic oncogenic consequences by causing chromosomal abnormalities.

  12. A dominantly acting murine allele of Mcm4 causes chromosomal abnormalities and promotes tumorigenesis.

    Science.gov (United States)

    Bagley, Bruce N; Keane, Thomas M; Maklakova, Vilena I; Marshall, Jonathon G; Lester, Rachael A; Cancel, Michelle M; Paulsen, Alex R; Bendzick, Laura E; Been, Raha A; Kogan, Scott C; Cormier, Robert T; Kendziorski, Christina; Adams, David J; Collier, Lara S

    2012-01-01

    Here we report the isolation of a murine model for heritable T cell lymphoblastic leukemia/lymphoma (T-ALL) called Spontaneous dominant leukemia (Sdl). Sdl heterozygous mice develop disease with a short latency and high penetrance, while mice homozygous for the mutation die early during embryonic development. Sdl mice exhibit an increase in the frequency of micronucleated reticulocytes, and T-ALLs from Sdl mice harbor small amplifications and deletions, including activating deletions at the Notch1 locus. Using exome sequencing it was determined that Sdl mice harbor a spontaneously acquired mutation in Mcm4 (Mcm4(D573H)). MCM4 is part of the heterohexameric complex of MCM2-7 that is important for licensing of DNA origins prior to S phase and also serves as the core of the replicative helicase that unwinds DNA at replication forks. Previous studies in murine models have discovered that genetic reductions of MCM complex levels promote tumor formation by causing genomic instability. However, Sdl mice possess normal levels of Mcms, and there is no evidence for loss-of-heterozygosity at the Mcm4 locus in Sdl leukemias. Studies in Saccharomyces cerevisiae indicate that the Sdl mutation produces a biologically inactive helicase. Together, these data support a model in which chromosomal abnormalities in Sdl mice result from the ability of MCM4(D573H) to incorporate into MCM complexes and render them inactive. Our studies indicate that dominantly acting alleles of MCMs can be compatible with viability but have dramatic oncogenic consequences by causing chromosomal abnormalities.

  13. Haplotype analysis and a novel allele-sharing method refines a chromosome 4p locus linked to bipolar affective disorder.

    Science.gov (United States)

    Le Hellard, Stephanie; Lee, Andrew J; Underwood, Sarah; Thomson, Pippa A; Morris, Stewart W; Torrance, Helen S; Anderson, Susan M; Adams, Richard R; Navarro, Pau; Christoforou, Andrea; Houlihan, Lorna M; Detera-Wadleigh, Sevilla; Owen, Michael J; Asherson, Philip; Muir, Walter J; Blackwood, Douglas H R; Wray, Naomi R; Porteous, David J; Evans, Kathryn L

    2007-03-15

    Bipolar affective disorder (BPAD) and schizophrenia (SCZ) are common conditions. Their causes are unknown, but they include a substantial genetic component. Previously, we described significant linkage of BPAD to a chromosome 4p locus within a large pedigree (F22). Others subsequently have found evidence for linkage of BPAD and SCZ to this region. We constructed high-resolution haplotypes for four linked families, calculated logarithm of the odds (LOD) scores, and developed a novel method to assess the extent of allele sharing within genes between the families. We describe an increase in the F22 LOD score for this region. Definition and comparison of the linked haplotypes allowed us to prioritize two subregions of 3.8 and 4.4 Mb. Analysis of the extent of allele sharing within these subregions identified 200 kb that shows increased allele sharing between families. Linkage of BPAD to chromosome 4p has been strengthened. Haplotype analysis in the additional linked families refined the 20-Mb linkage region. Development of a novel allele-sharing method allowed us to bridge the gap between conventional linkage and association studies. Description of a 200-kb region of increased allele sharing prioritizes this region, which contains two functional candidate genes for BPAD, SLC2A9, and WDR1, for subsequent studies.

  14. Functional PMS2 hybrid alleles containing a pseudogene-specific missense variant trace back to a single ancient intrachromosomal recombination event.

    Science.gov (United States)

    Ganster, Christina; Wernstedt, Annekatrin; Kehrer-Sawatzki, Hildegard; Messiaen, Ludwine; Schmidt, Konrad; Rahner, Nils; Heinimann, Karl; Fonatsch, Christa; Zschocke, Johannes; Wimmer, Katharina

    2010-05-01

    Sequence exchange between PMS2 and its pseudogene PMS2CL, embedded in an inverted duplication on chromosome 7p22, has been reported to be an ongoing process that leads to functional PMS2 hybrid alleles containing PMS2- and PMS2CL-specific sequence variants at the 5'-and the 3'-end, respectively. The frequency of PMS2 hybrid alleles, their biological significance, and the mechanisms underlying their formation are largely unknown. Here we show that overall hybrid alleles account for one-third of 384 PMS2 alleles analyzed in individuals of different ethnic backgrounds. Depending on the population, 14-60% of hybrid alleles carry PMS2CL-specific sequences in exons 13-15, the remainder only in exon 15. We show that exons 13-15 hybrid alleles, named H1 hybrid alleles, constitute different haplotypes but trace back to a single ancient intrachromosomal recombination event with crossover. Taking advantage of an ancestral sequence variant specific for all H1 alleles we developed a simple gDNA-based polymerase chain reaction (PCR) assay that can be used to identify H1-allele carriers with high sensitivity and specificity (100 and 99%, respectively). Because H1 hybrid alleles harbor missense variant p.N775S of so far unknown functional significance, we assessed the H1-carrier frequency in 164 colorectal cancer patients. So far, we found no indication that the variant plays a major role with regard to cancer susceptibility. (c) 2010 Wiley-Liss, Inc.

  15. Screening for SNPs with Allele-Specific Methylation based on Next-Generation Sequencing Data.

    Science.gov (United States)

    Hu, Bo; Ji, Yuan; Xu, Yaomin; Ting, Angela H

    2013-05-01

    Allele-specific methylation (ASM) has long been studied but mainly documented in the context of genomic imprinting and X chromosome inactivation. Taking advantage of the next-generation sequencing technology, we conduct a high-throughput sequencing experiment with four prostate cell lines to survey the whole genome and identify single nucleotide polymorphisms (SNPs) with ASM. A Bayesian approach is proposed to model the counts of short reads for each SNP conditional on its genotypes of multiple subjects, leading to a posterior probability of ASM. We flag SNPs with high posterior probabilities of ASM by accounting for multiple comparisons based on posterior false discovery rates. Applying the Bayesian approach to the in-house prostate cell line data, we identify 269 SNPs as candidates of ASM. A simulation study is carried out to demonstrate the quantitative performance of the proposed approach.

  16. DQB1*06:02 allele-specific expression varies by allelic dosage, not narcolepsy status

    DEFF Research Database (Denmark)

    Weiner Lachmi, Karin; Lin, Ling; Kornum, Birgitte Rahbek

    2012-01-01

    The association of narcolepsy-cataplexy, a sleep disorder caused by the loss of hypocretin/orexin neurons in the hypothalamus, with DQA1*01:02-DQB1*06:02 is one of the tightest known single-allele human leukocyte antigen (HLA) associations. In this study, we explored genome-wide expression...

  17. Allelic interaction of F1 pollen sterility loci and abnormal chromosome behaviour caused pollen sterility in intersubspecific autotetraploid rice hybrids.

    Science.gov (United States)

    He, J H; Shahid, M Q; Li, Y J; Guo, H B; Cheng, X A; Liu, X D; Lu, Y G

    2011-08-01

    The intersubspecific hybrids of autotetraploid rice has many features that increase rice yield, but lower seed set is a major hindrance in its utilization. Pollen sterility is one of the most important factors which cause intersubspecific hybrid sterility. The hybrids with greater variation in seed set were used to study how the F(1) pollen sterile loci (S-a, S-b, and S-c) interact with each other and how abnormal chromosome behaviour and allelic interaction of F(1) sterility loci affect pollen fertility and seed set of intersubspecific autotetraploid rice hybrids. The results showed that interaction between pollen sterility loci have significant effects on the pollen fertility of autotetraploid hybrids, and pollen fertility further decreased with an increase in the allelic interaction of F(1) pollen sterility loci. Abnormal ultra-structure and microtubule distribution patterns during pollen mother cell (PMC) meiosis were found in the hybrids with low pollen fertility in interphase and leptotene, suggesting that the effect-time of pollen sterility loci interaction was very early. There were highly significant differences in the number of quadrivalents and bivalents, and in chromosome configuration among all the hybrids, and quadrivalents decreased with an increase in the seed set of autotetraploid hybrids. Many different kinds of chromosomal abnormalities, such as chromosome straggling, chromosome lagging, asynchrony of chromosome disjunction, and tri-fission were found during the various developmental stages of PMC meiosis. All these abnormalities were significantly higher in sterile hybrids than in fertile hybrids, suggesting that pollen sterility gene interactions tend to increase the chromosomal abnormalities which cause the partial abortion of male gametes and leads to the decline in the seed set of the autotetraploid rice hybrids. © 2011 The Author(s).

  18. HIM-8 binds to the X chromosome pairing center and mediates chromosome-specific meiotic synapsis.

    Science.gov (United States)

    Phillips, Carolyn M; Wong, Chihunt; Bhalla, Needhi; Carlton, Peter M; Weiser, Pinky; Meneely, Philip M; Dernburg, Abby F

    2005-12-16

    The him-8 gene is essential for proper meiotic segregation of the X chromosomes in C. elegans. Here we show that loss of him-8 function causes profound X chromosome-specific defects in homolog pairing and synapsis. him-8 encodes a C2H2 zinc-finger protein that is expressed during meiosis and concentrates at a site on the X chromosome known as the meiotic pairing center (PC). A role for HIM-8 in PC function is supported by genetic interactions between PC lesions and him-8 mutations. HIM-8 bound chromosome sites associate with the nuclear envelope (NE) throughout meiotic prophase. Surprisingly, a point mutation in him-8 that retains both chromosome binding and NE localization fails to stabilize pairing or promote synapsis. These observations indicate that stabilization of homolog pairing is an active process in which the tethering of chromosome sites to the NE may be necessary but is not sufficient.

  19. HIM-8 binds to the X chromosome pairing center and mediates chromosome-specific meiotic synapsis

    International Nuclear Information System (INIS)

    Phillips, Carolyn M.; Wong, Chihunt; Bhalla, Needhi; Carlton, Peter M.; Weiser, Pinky; Meneely, Philip M.; Dernburg, Abby F.

    2005-01-01

    The him-8 gene is essential for proper meiotic segregation of the X chromosomes in C. elegans. Here we show that loss of him-8 function causes profound X-chromosome-specific defects in homolog pairing and synapsis.him-8 encodes a C2H2 zinc finger protein that is expressed during meiosis and concentrates at a site on the X chromosome known as themeiotic Pairing Center (PC). A role for HIM-8 in PC function is supported by genetic interactions between PC lesions and him-8 mutations. HIM-8-bound chromosome sites associate with the nuclear envelope (NE)throughout meiotic prophase. Surprisingly, a point mutation in him-8 that retains both chromosome binding and NE localization fails to stabilize pairing or promote synapsis. These observations indicate that stabilization of homolog pairing is an active process in which the tethering of chromosome sites to the NE may be necessary but is not sufficient

  20. Allele specific expression in worker reproduction genes in the bumblebee Bombus terrestris

    Directory of Open Access Journals (Sweden)

    Harindra E. Amarasinghe

    2015-07-01

    Full Text Available Methylation has previously been associated with allele specific expression in ants. Recently, we found methylation is important in worker reproduction in the bumblebee Bombus terrestris. Here we searched for allele specific expression in twelve genes associated with worker reproduction in bees. We found allele specific expression in Ecdysone 20 monooxygenase and IMP-L2-like. Although we were unable to confirm a genetic or epigenetic cause for this allele specific expression, the expression patterns of the two genes match those predicted for imprinted genes.

  1. Genetic recombination variation in wild Robertsonian mice: on the role of chromosomal fusions and Prdm9 allelic background.

    Science.gov (United States)

    Capilla, Laia; Medarde, Nuria; Alemany-Schmidt, Alexandra; Oliver-Bonet, Maria; Ventura, Jacint; Ruiz-Herrera, Aurora

    2014-07-07

    Despite the existence of formal models to explain how chromosomal rearrangements can be fixed in a population in the presence of gene flow, few empirical data are available regarding the mechanisms by which genome shuffling contributes to speciation, especially in mammals. In order to shed light on this intriguing evolutionary process, here we present a detailed empirical study that shows how Robertsonian (Rb) fusions alter the chromosomal distribution of recombination events during the formation of the germline in a Rb system of the western house mouse (Mus musculus domesticus). Our results indicate that both the total number of meiotic crossovers and the chromosomal distribution of recombination events are reduced in mice with Rb fusions and that this can be related to alterations in epigenetic signatures for heterochromatinization. Furthermore, we detected novel house mouse Prdm9 allelic variants in the Rb system. Remarkably, mean recombination rates were positively correlated with a decrease in the number of ZnF domains in the Prdm9 gene. The suggestion that recombination can be modulated by both chromosomal reorganizations and genetic determinants that control the formation of double-stranded breaks during meiosis opens new avenues for understanding the role of recombination in chromosomal speciation. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  2. Chromosomal Location by Use of Trisomics and New Alleles of an Endopeptidase in Zea Mays

    DEFF Research Database (Denmark)

    Nielsen, Gunnar Gissel; Scandalios, John G.

    1974-01-01

    An association was found earlier between the Ep1 gene locus coding for an endopeptidase and the endosperm color gene Y1 on chromosome 6 of Zea mays. By employing primary trisomics we have unequivocally placed the Ep1 gene on chromosome 6, closely linked to the Y1 locus. Additionally we describe new...

  3. Paternal or Maternal Uniparental Disomy of Chromosome 16 Resulting in Homozygosity of a Mutant Allele Causes Fanconi Anemia.

    Science.gov (United States)

    Donovan, Frank X; Kimble, Danielle C; Kim, Yonghwan; Lach, Francis P; Harper, Ursula; Kamat, Aparna; Jones, MaryPat; Sanborn, Erica M; Tryon, Rebecca; Wagner, John E; MacMillan, Margaret L; Ostrander, Elaine A; Auerbach, Arleen D; Smogorzewska, Agata; Chandrasekharappa, Settara C

    2016-05-01

    Fanconi anemia (FA) is a rare inherited disorder caused by pathogenic variants in one of 19 FANC genes. FA patients display congenital abnormalities, and develop bone marrow failure, and cancer susceptibility. We identified homozygous mutations in four FA patients and, in each case, only one parent carried the obligate mutant allele. FANCA and FANCP/SLX4 genes, both located on chromosome 16, were the affected recessive FA genes in three and one family respectively. Genotyping with short tandem repeat markers and SNP arrays revealed uniparental disomy (UPD) of the entire mutation-carrying chromosome 16 in all four patients. One FANCA patient had paternal UPD, whereas FA in the other three patients resulted from maternal UPD. These are the first reported cases of UPD as a cause of FA. UPD indicates a reduced risk of having another child with FA in the family and has implications in prenatal diagnosis. © 2016 WILEY PERIODICALS, INC.

  4. Associations of recurrent miscarriages with chromosomal abnormalities, thrombophilia allelic polymorphisms and/or consanguinity in Saudi Arabia.

    Science.gov (United States)

    Turki, Rola F; Assidi, Mourad; Banni, Huda A; Zahed, Hanan A; Karim, Sajjad; Schulten, Hans-Juergen; Abu-Elmagd, Muhammad; Rouzi, Abdulrahim A; Bajouh, Osama; Jamal, Hassan S; Al-Qahtani, Mohammed H; Abuzenadah, Adel M

    2016-10-10

    Recurrent pregnancy loss (RPL) or recurrent spontaneous abortion is an obstetric complication that affects couples at reproductive age. Previous reports documented a clear relationship between parents with chromosomal abnormalities and both recurrent miscarriages and infertility. However, limited data is available from the Arabian Peninsula which is known by higher rates of consanguineous marriages. The main goal of this study was to determine the prevalence of chromosomal abnormalities and thrombophilic polymorphisms, and to correlate them with RPL and consanguinity in Saudi Arabia. Cytogenetic analysis of 171 consent patients with RPL was performed by the standard method of 72-h lymphocyte culture and GTG banding. Allelic polymorphisms of three thrombophilic genes (Factor V Leiden, Prothrombin A20210G, MTHFR C677T) were performed using PCR-RFLP (restriction fragment length polymorphism) and gel electrophoresis. Data analysis revealed that 7.6 % of patients were carrier of numerical or structural chromosomal abnormalities. A high rate of translocations (46 %) was associated to increased incidence of RPL. A significant correlation between consanguineous RPL patients and chromosomal abnormalities (P consanguineous marriages in the Saudi population, these results underline the importance of systematic cytogenetic investigation and genetic counseling preferably at the premarital stage or at least during early pregnancy phase through preimplantation genetic diagnosis (PGD).

  5. Metastic Progression of Breast Cancer by Allelic Loss on Chromosome 18q21

    National Research Council Canada - National Science Library

    Thiagalingam, Sam

    2006-01-01

    Genetic and epigenetic inactivation of SMAD4 are rare occurrences in breast tumors despite it is localized to chromosome 18q and serves as a frequent target for inactivation in advanced gastrointestinal cancers...

  6. Allelic inhibition of displacement activity: a simplified one tube allele-specific PCR for evaluation of ITPA polymorphisms.

    Science.gov (United States)

    Galmozzi, E; Facchetti, F; Degasperi, E; Aghemo, A; Lampertico, P

    2013-02-01

    Recently, genome-wide association studies (GWAS) in patients with chronic hepatitis C virus (HCV) infection have identified two functional single nucleotide polymorphisms (SNPs) in the inosine triphosphatase (ITPA) gene, that are associated strongly and independently with hemolytic anemia in patients exposed to pegylated-interferon (Peg-IFN) plus ribavirin (RBV) combined therapy. Here has been developed a simplified allele discrimination polymerase chain reaction (PCR) assay named allelic inhibition of displacement activity (AIDA) for evaluation of ITPA polymorphisms. AIDA system relies on three unlabeled primers only, two outer common primers and one inner primer with allele-specific 3' terminus mismatch. DNA samples from 192 patients with chronic HCV infection were used to validate the AIDA system and results were compared with the gold standard TaqMan(®) SNP genotyping assay. Concordant data were obtained for all samples, granting for high specificity of the method. In conclusion, AIDA is a practical one-tube method to reproducibly and to assess accurately rs7270101 and rs1127354 ITPA SNPs. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. The Charles River "hairless" rat mutation maps to chromosome 1: allelic with fuzzy and a likely orthologue of mouse frizzy.

    Science.gov (United States)

    Ahearn, K; Akkouris, G; Berry, P R; Chrissluis, R R; Crooks, I M; Dull, A K; Grable, S; Jeruzal, J; Lanza, J; Lavoie, C; Maloney, R A; Pitruzzello, M; Sharma, R; Stoklasek, T A; Tweeddale, J; King, T R

    2002-01-01

    Recent evidence has indicated that the recessive mutation affecting hypotrichosis in the Charles River (CR) "hairless" rat does not involve the hairless gene (hr) on rat chromosome 15. To determine if this mutation might be allelic (or orthologous) with any other previously mapped hypotrichosis-generating mutation in mammals, we have produced a panel of backcross rats segregating for the CR hairless rat mutation as well as numerous other markers from throughout the rat genome. Analysis of this panel has located the CR hairless rat's hypotrichosis-generating mutation on chromosome 1, near Myl2, where only the fuzzy mutation in rat (fz) and the frizzy mutation in mouse (fr) have been previously localized. Intercrossing fz/fz and CR hairless rats produced hybrid offspring with abnormal hair, showing that these two rat mutations are allelic. We suggest that the CR hairless rat mutation and fuzzy be renamed frizzy-Charles River (fr(CR)) and frizzy-Harlan (fr(H)), respectively, to reflect their likely orthology with the mouse fr mutation.

  8. Allele-Specific Alternative mRNA processing (ASARP) | Informatics Technology for Cancer Research (ITCR)

    Science.gov (United States)

    A software pipeline for prediction of allele-specific alternative RNA processing events using single RNA-seq data. The current version focuses on prediction of alternative splicing and alternative polyadenylation modulated by genetic variants.

  9. Allele-specific characterization of alanine: glyoxylate aminotransferase variants associated with primary hyperoxaluria.

    Directory of Open Access Journals (Sweden)

    Melissa D Lage

    Full Text Available Primary Hyperoxaluria Type 1 (PH1 is a rare autosomal recessive kidney stone disease caused by deficiency of the peroxisomal enzyme alanine: glyoxylate aminotransferase (AGT, which is involved in glyoxylate detoxification. Over 75 different missense mutations in AGT have been found associated with PH1. While some of the mutations have been found to affect enzyme activity, stability, and/or localization, approximately half of these mutations are completely uncharacterized. In this study, we sought to systematically characterize AGT missense mutations associated with PH1. To facilitate analysis, we used two high-throughput yeast-based assays: one that assesses AGT specific activity, and one that assesses protein stability. Approximately 30% of PH1-associated missense mutations are found in conjunction with a minor allele polymorphic variant, which can interact to elicit complex effects on protein stability and trafficking. To better understand this allele interaction, we functionally characterized each of 34 mutants on both the major (wild-type and minor allele backgrounds, identifying mutations that synergize with the minor allele. We classify these mutants into four distinct categories depending on activity/stability results in the different alleles. Twelve mutants were found to display reduced activity in combination with the minor allele, compared with the major allele background. When mapped on the AGT dimer structure, these mutants reveal localized regions of the protein that appear particularly sensitive to interactions with the minor allele variant. While the majority of the deleterious effects on activity in the minor allele can be attributed to synergistic interaction affecting protein stability, we identify one mutation, E274D, that appears to specifically affect activity when in combination with the minor allele.

  10. QuASAR-MPRA: accurate allele-specific analysis for massively parallel reporter assays.

    Science.gov (United States)

    Kalita, Cynthia A; Moyerbrailean, Gregory A; Brown, Christopher; Wen, Xiaoquan; Luca, Francesca; Pique-Regi, Roger

    2018-03-01

    The majority of the human genome is composed of non-coding regions containing regulatory elements such as enhancers, which are crucial for controlling gene expression. Many variants associated with complex traits are in these regions, and may disrupt gene regulatory sequences. Consequently, it is important to not only identify true enhancers but also to test if a variant within an enhancer affects gene regulation. Recently, allele-specific analysis in high-throughput reporter assays, such as massively parallel reporter assays (MPRAs), have been used to functionally validate non-coding variants. However, we are still missing high-quality and robust data analysis tools for these datasets. We have further developed our method for allele-specific analysis QuASAR (quantitative allele-specific analysis of reads) to analyze allele-specific signals in barcoded read counts data from MPRA. Using this approach, we can take into account the uncertainty on the original plasmid proportions, over-dispersion, and sequencing errors. The provided allelic skew estimate and its standard error also simplifies meta-analysis of replicate experiments. Additionally, we show that a beta-binomial distribution better models the variability present in the allelic imbalance of these synthetic reporters and results in a test that is statistically well calibrated under the null. Applying this approach to the MPRA data, we found 602 SNPs with significant (false discovery rate 10%) allele-specific regulatory function in LCLs. We also show that we can combine MPRA with QuASAR estimates to validate existing experimental and computational annotations of regulatory variants. Our study shows that with appropriate data analysis tools, we can improve the power to detect allelic effects in high-throughput reporter assays. http://github.com/piquelab/QuASAR/tree/master/mpra. fluca@wayne.edu or rpique@wayne.edu. Supplementary data are available online at Bioinformatics. © The Author (2017). Published by

  11. The restriction-modification genes of Escherichia coli K-12 may not be selfish: they do not resist loss and are readily replaced by alleles conferring different specificities.

    Science.gov (United States)

    O'Neill, M; Chen, A; Murray, N E

    1997-12-23

    Type II restriction and modification (R-M) genes have been described as selfish because they have been shown to impose selection for the maintenance of the plasmid that encodes them. In our experiments, the type I R-M system EcoKI does not behave in the same way. The genes specifying EcoKI are, however, normally residents of the chromosome and therefore our analyses were extended to monitor the deletion of chromosomal genes rather than loss of plasmid vector. If EcoKI were to behave in the same way as the plasmid-encoded type II R-M systems, the loss of the relevant chromosomal genes by mutation or recombination should lead to cell death because the cell would become deficient in modification enzyme and the bacterial chromosome would be vulnerable to the restriction endonuclease. Our data contradict this prediction; they reveal that functional type I R-M genes in the chromosome are readily replaced by mutant alleles and by alleles encoding a type I R-M system of different specificity. The acquisition of allelic genes conferring a new sequence specificity, but not the loss of the resident genes, is dependent on the product of an unlinked gene, one predicted [Prakash-Cheng, A., Chung, S. S. & Ryu, J. (1993) Mol. Gen. Genet. 241, 491-496] to be relevant to control of expression of the genes that encode EcoKI. Our evidence suggests that not all R-M systems are evolving as "selfish" units; rather, the diversity and distribution of the family of type I enzymes we have investigated require an alternative selective pressure.

  12. A large-scale chromosome-specific SNP discovery guideline.

    Science.gov (United States)

    Akpinar, Bala Ani; Lucas, Stuart; Budak, Hikmet

    2017-01-01

    Single-nucleotide polymorphisms (SNPs) are the most prevalent type of variation in genomes that are increasingly being used as molecular markers in diversity analyses, mapping and cloning of genes, and germplasm characterization. However, only a few studies reported large-scale SNP discovery in Aegilops tauschii, restricting their potential use as markers for the low-polymorphic D genome. Here, we report 68,592 SNPs found on the gene-related sequences of the 5D chromosome of Ae. tauschii genotype MvGB589 using genomic and transcriptomic sequences from seven Ae. tauschii accessions, including AL8/78, the only genotype for which a draft genome sequence is available at present. We also suggest a workflow to compare SNP positions in homologous regions on the 5D chromosome of Triticum aestivum, bread wheat, to mark single nucleotide variations between these closely related species. Overall, the identified SNPs define a density of 4.49 SNPs per kilobyte, among the highest reported for the genic regions of Ae. tauschii so far. To our knowledge, this study also presents the first chromosome-specific SNP catalog in Ae. tauschii that should facilitate the association of these SNPs with morphological traits on chromosome 5D to be ultimately targeted for wheat improvement.

  13. Chromosome

    Science.gov (United States)

    ... St Louis, MO: Elsevier; 2017:chap 69. Taber's Medical Dictionary Online. Chromosome. www.tabers.com/tabersonline/view/Tabers-Dictionary/753321/all/chromosome?q=Chromosome&ti=0 . Accessed June 11, 2017.

  14. Allele-specific cytokine responses at the HLA-C locus, implications for psoriasis

    Science.gov (United States)

    Hundhausen, Christian; Bertoni, Anna; Mak, Rose K; Botti, Elisabetta; Di Meglio, Paola; Clop, Alex; Laggner, Ute; Chimenti, Sergio; Hayday, Adrian C; Barker, Jonathan N; Trembath, Richard C; Capon, Francesca; Nestle, Frank O

    2011-01-01

    Psoriasis is an inflammatory skin disorder that is inherited as a complex trait. Genetic studies have repeatedly highlighted HLA-C as the major determinant for psoriasis susceptibility, with the Cw*0602 allele conferring significant disease risk in a wide-range of populations. Despite the potential importance of HLA-C variation in psoriasis, either via an effect on peptide presentation or immuno-inhibitory activity, allele-specific expression patterns have not been investigated. Here, we used reporter assays to characterize two regulatory variants, which virtually abolished the response to TNF-α (rs2524094) and IFN-γ (rs10657191) in HLA-Cw*0602 and a cluster of related alleles. We validated these findings through the analysis of HLA-Cw*0602 expression in primary keratinocytes treated with TNF-α and IFN-γ. Finally, we showed that HLA-Cw*0602 transcripts are not increased in psoriatic skin lesions, despite highly elevated TNF-α levels. Thus, our findings demonstrate the presence of allele-specific differences in HLA-C expression and indicate that HLA-Cw*0602 is unresponsive to up-regulation by key pro-inflammatory cytokines in psoriasis. These data pave the way for functional studies into the pathogenic role of the major psoriasis susceptibility allele. PMID:22113476

  15. Allele-specific cytokine responses at the HLA-C locus: implications for psoriasis.

    Science.gov (United States)

    Hundhausen, Christian; Bertoni, Anna; Mak, Rose K; Botti, Elisabetta; Di Meglio, Paola; Clop, Alex; Laggner, Ute; Chimenti, Sergio; Hayday, Adrian C; Barker, Jonathan N; Trembath, Richard C; Capon, Francesca; Nestle, Frank O

    2012-03-01

    Psoriasis is an inflammatory skin disorder that is inherited as a complex trait. Genetic studies have repeatedly highlighted HLA-C as the major determinant for psoriasis susceptibility, with the Cw*0602 allele conferring significant disease risk in a wide range of populations. Despite the potential importance of HLA-C variation in psoriasis, either via an effect on peptide presentation or immuno-inhibitory activity, allele-specific expression patterns have not been investigated. Here, we used reporter assays to characterize two regulatory variants, which virtually abolished the response to tumor necrosis factor (TNF)-α (rs2524094) and IFN-γ (rs10657191) in HLA-Cw*0602 and a cluster of related alleles. We validated these findings through the analysis of HLA-Cw*0602 expression in primary keratinocytes treated with TNF-α and IFN-γ. Finally, we showed that HLA-Cw*0602 transcripts are not increased in psoriatic skin lesions, despite highly elevated TNF-α levels. Thus, our findings demonstrate the presence of allele-specific differences in HLA-C expression and indicate that HLA-Cw*0602 is unresponsive to upregulation by key proinflammatory cytokines in psoriasis. These data pave the way for functional studies into the pathogenic role of the major psoriasis susceptibility allele.

  16. Enhancement of allele discrimination by introduction of nucleotide mismatches into siRNA in allele-specific gene silencing by RNAi.

    Directory of Open Access Journals (Sweden)

    Yusuke Ohnishi

    Full Text Available Allele-specific gene silencing by RNA interference (RNAi is therapeutically useful for specifically inhibiting the expression of disease-associated alleles without suppressing the expression of corresponding wild-type alleles. To realize such allele-specific RNAi (ASP-RNAi, the design and assessment of small interfering RNA (siRNA duplexes conferring ASP-RNAi is vital; however, it is also difficult. In a previous study, we developed an assay system to assess ASP-RNAi with mutant and wild-type reporter alleles encoding the Photinus and Renilla luciferase genes. In line with experiments using the system, we realized that it is necessary and important to enhance allele discrimination between mutant and corresponding wild-type alleles. Here, we describe the improvement of ASP-RNAi against mutant alleles carrying single nucleotide variations by introducing base substitutions into siRNA sequences, where original variations are present in the central position. Artificially mismatched siRNAs or short-hairpin RNAs (shRNAs against mutant alleles of the human Prion Protein (PRNP gene, which appear to be associated with susceptibility to prion diseases, were examined using this assessment system. The data indicates that introduction of a one-base mismatch into the siRNAs and shRNAs was able to enhance discrimination between the mutant and wild-type alleles. Interestingly, the introduced mismatches that conferred marked improvement in ASP-RNAi, appeared to be largely present in the guide siRNA elements, corresponding to the 'seed region' of microRNAs. Due to the essential role of the 'seed region' of microRNAs in their association with target RNAs, it is conceivable that disruption of the base-pairing interactions in the corresponding seed region, as well as the central position (involved in cleavage of target RNAs, of guide siRNA elements could influence allele discrimination. In addition, we also suggest that nucleotide mismatches at the 3'-ends of sense

  17. Sex chromosome-specific regulation in the Drosophila male germline but little evidence for chromosomal dosage compensation or meiotic inactivation.

    Directory of Open Access Journals (Sweden)

    Colin D Meiklejohn

    2011-08-01

    Full Text Available The evolution of heteromorphic sex chromosomes (e.g., XY in males or ZW in females has repeatedly elicited the evolution of two kinds of chromosome-specific regulation: dosage compensation--the equalization of X chromosome gene expression in males and females--and meiotic sex chromosome inactivation (MSCI--the transcriptional silencing and heterochromatinization of the X during meiosis in the male (or Z in the female germline. How the X chromosome is regulated in the Drosophila melanogaster male germline is unclear. Here we report three new findings concerning gene expression from the X in Drosophila testes. First, X chromosome-wide dosage compensation appears to be absent from most of the Drosophila male germline. Second, microarray analysis provides no evidence for X chromosome-specific inactivation during meiosis. Third, we confirm the previous discovery that the expression of transgene reporters driven by autosomal spermatogenesis-specific promoters is strongly reduced when inserted on the X chromosome versus the autosomes; but we show that this chromosomal difference in expression is established in premeiotic cells and persists in meiotic cells. The magnitude of the X-autosome difference in transgene expression cannot be explained by the absence of dosage compensation, suggesting that a previously unrecognized mechanism limits expression from the X during spermatogenesis in Drosophila. These findings help to resolve several previously conflicting reports and have implications for patterns of genome evolution and speciation in Drosophila.

  18. An informational view of accession rarity and allele specificity in germplasm banks for management and conservation.

    Science.gov (United States)

    Reyes-Valdés, M Humberto; Burgueño, Juan; Singh, Sukhwinder; Martínez, Octavio; Sansaloni, Carolina Paola

    2018-01-01

    Germplasm banks are growing in their importance, number of accessions and amount of characterization data, with a large emphasis on molecular genetic markers. In this work, we offer an integrated view of accessions and marker data in an information theory framework. The basis of this development is the mutual information between accessions and allele frequencies for molecular marker loci, which can be decomposed in allele specificities, as well as in rarity and divergence of accessions. In this way, formulas are provided to calculate the specificity of the different marker alleles with reference to their distribution across accessions, accession rarity, defined as the weighted average of the specificity of its alleles, and divergence, defined by the Kullback-Leibler formula. Albeit being different measures, it is demonstrated that average rarity and divergence are equal for any collection. These parameters can contribute to the knowledge of the structure of a germplasm collection and to make decisions about the preservation of rare variants. The concepts herein developed served as the basis for a strategy for core subset selection called HCore, implemented in a publicly available R script. As a proof of concept, the mathematical view and tools developed in this research were applied to a large collection of Mexican wheat accessions, widely characterized by SNP markers. The most specific alleles were found to be private of a single accession, and the distribution of this parameter had its highest frequencies at low levels of specificity. Accession rarity and divergence had largely symmetrical distributions, and had a positive, albeit non-strictly linear relationship. Comparison of the HCore approach for core subset selection, with three state-of-the-art methods, showed it to be superior for average divergence and rarity, mean genetic distance and diversity. The proposed approach can be used for knowledge extraction and decision making in germplasm collections of

  19. Simultaneous SNP identification and assessment of allele-specific bias from ChIP-seq data

    Directory of Open Access Journals (Sweden)

    Ni Yunyun

    2012-09-01

    Full Text Available Abstract Background Single nucleotide polymorphisms (SNPs have been associated with many aspects of human development and disease, and many non-coding SNPs associated with disease risk are presumed to affect gene regulation. We have previously shown that SNPs within transcription factor binding sites can affect transcription factor binding in an allele-specific and heritable manner. However, such analysis has relied on prior whole-genome genotypes provided by large external projects such as HapMap and the 1000 Genomes Project. This requirement limits the study of allele-specific effects of SNPs in primary patient samples from diseases of interest, where complete genotypes are not readily available. Results In this study, we show that we are able to identify SNPs de novo and accurately from ChIP-seq data generated in the ENCODE Project. Our de novo identified SNPs from ChIP-seq data are highly concordant with published genotypes. Independent experimental verification of more than 100 sites estimates our false discovery rate at less than 5%. Analysis of transcription factor binding at de novo identified SNPs revealed widespread heritable allele-specific binding, confirming previous observations. SNPs identified from ChIP-seq datasets were significantly enriched for disease-associated variants, and we identified dozens of allele-specific binding events in non-coding regions that could distinguish between disease and normal haplotypes. Conclusions Our approach combines SNP discovery, genotyping and allele-specific analysis, but is selectively focused on functional regulatory elements occupied by transcription factors or epigenetic marks, and will therefore be valuable for identifying the functional regulatory consequences of non-coding SNPs in primary disease samples.

  20. Sex-specific allelic transmission bias suggests sexual conflict at MC1R.

    Science.gov (United States)

    Ducret, Valérie; Gaigher, Arnaud; Simon, Céline; Goudet, Jérôme; Roulin, Alexandre

    2016-09-01

    Sexual conflict arises when selection in one sex causes the displacement of the other sex from its phenotypic optimum, leading to an inevitable tension within the genome - called intralocus sexual conflict. Although the autosomal melanocortin-1-receptor gene (MC1R) can generate colour variation in sexually dichromatic species, most previous studies have not considered the possibility that MC1R may be subject to sexual conflict. In the barn owl (Tyto alba), the allele MC1RWHITE is associated with whitish plumage coloration, typical of males, and the allele MC1RRUFOUS is associated with dark rufous coloration, typical of females, although each sex can express any phenotype. Because each colour variant is adapted to specific environmental conditions, the allele MC1RWHITE may be more strongly selected in males and the allele MC1RRUFOUS in females. We therefore investigated whether MC1R genotypes are in excess or deficit in male and female fledglings compared with the expected Hardy-Weinberg proportions. Our results show an overall deficit of 7.5% in the proportion of heterozygotes in males and of 12.9% in females. In males, interannual variation in assortative pairing with respect to MC1R explained the year-specific deviations from Hardy-Weinberg proportions, whereas in females, the deficit was better explained by the interannual variation in the probability of inheriting the MC1RWHITE or MC1RRUFOUS allele. Additionally, we observed that sons inherit the MC1RRUFOUS allele from their fathers on average slightly less often than expected under the first Mendelian law. Transmission ratio distortion may be adaptive in this sexually dichromatic species if males and females are, respectively, selected to display white and rufous plumages. © 2016 John Wiley & Sons Ltd.

  1. Characterization of a chromosome-specific chimpanzee alpha satellite subset: Evolutionary relationship to subsets on human chromosomes

    Energy Technology Data Exchange (ETDEWEB)

    Warburton, P.E.; Gosden, J.; Lawson, D. [Western General Hospital, Edinburgh (United Kingdom)] [and others

    1996-04-15

    Alpha satellite DNA is a tandemly repeated DNA family found at the centromeres of all primate chromosomes examined. The fundamental repeat units of alpha satellite DNA are diverged 169- to 172-bp monomers, often found to be organized in chromosome-specific higher-order repeat units. The chromosomes of human (Homo sapiens (HSA)), chimpanzee (Pan troglodytes (PTR) and Pan paniscus), and gorilla (Gorilla gorilla) share a remarkable similarity and synteny. It is of interest to ask if alpha satellite arrays at centromeres of homologous chromosomes between these species are closely related (evolving in an orthologous manner) or if the evolutionary processes that homogenize and spread these arrays within and between chromosomes result in nonorthologous evolution of arrays. By using PCR primers specific for human chromosome 17-specific alpha satellite DNA, we have amplified, cloned, and characterized a chromosome-specific subset from the PTR chimpanzee genome. Hybridization both on Southern blots and in situ as well as sequence analysis show that this subset is most closely related, as expected, to sequences on HSA 17. However, in situ hybridization reveals that this subset is not found on the homologous chromosome in chimpanzee (PTR 19), but instead on PTR 12, which is homologous to HSA 2p. 40 refs., 3 figs.

  2. A de novo mosaic mutation in SPAST with two novel alternative alleles and chromosomal copy number variant in a boy with spastic paraplegia and autism spectrum disorder.

    Science.gov (United States)

    Matthews, A M; Tarailo-Graovac, M; Price, E M; Blydt-Hansen, I; Ghani, A; Drögemöller, B I; Robinson, W P; Ross, C J; Wasserman, W W; Siden, H; van Karnebeek, C D

    2017-10-01

    Here we report a 12 year old male with an extreme presentation of spastic paraplegia along with autism and dysmorphisms. Whole exome sequencing identified a predicted pathogenic pair of missense variants in SPAST at the same chromosomal location, each with a different alternative allele, while a chromosome microarray identified a 1.73 Mb paternally inherited copy gain of 1q21.1q21.2 resulting in a blended phenotype of both Spastic paraplegia 4 and 1q21.1 microduplication syndrome. We believe that the extreme phenotype observed is likely caused by the presence of cells which contain only mutant SPAST, but that the viability of the patient is possible due mosaicism of mutant alleles observed in different proportions across tissues. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  3. A small asparagine-rich protein required for S-allele-specific pollen rejection in Nicotiana.

    Science.gov (United States)

    McClure, B; Mou, B; Canevascini, S; Bernatzky, R

    1999-11-09

    Although S-locus RNases (S-RNases) determine the specificity of pollen rejection in self-incompatible (SI) solanaceous plants, they alone are not sufficient to cause S-allele-specific pollen rejection. To identify non-S-RNase sequences that are required for pollen rejection, a Nicotiana alata cDNA library was screened by differential hybridization. One clone, designated HT, hybridized strongly to RNA from N. alata styles but not to RNA from Nicotiana plumbaginifolia, a species known to lack one or more factors necessary for S-allele-specific pollen rejection. Sequence analysis revealed a 101-residue ORF including a putative secretion signal and an asparagine-rich domain near the C terminus. RNA blot analysis showed that the HT-transcript accumulates in the stigma and style before anthesis. The timing of HT-expression lags slightly behind S(C10)-RNase in SI N. alata S(C10)S(C10) and is well correlated with the onset of S-allele-specific pollen rejection in the style. An antisense-HT construct was prepared to test for a role in pollen rejection. Transformed (N. plumbaginifolia x SI N. alata S(C10)S(C10)) hybrids with reduced levels of HT-protein continued to express S(C10)-RNase but failed to reject S(C10)-pollen. Control hybrids expressing both S(C10)-RNase and HT-protein showed a normal S-allele-specific pollen rejection response. We conclude that HT-protein is directly implicated in pollen rejection.

  4. Chromosome-specific staining to detect genetic rearrangements

    Energy Technology Data Exchange (ETDEWEB)

    Gray, Joe W.; Pinkel, Daniel; Tkachuk, Douglas; Westbrook, Carol

    2013-04-09

    Methods and compositions for staining based upon nucleic acid sequence that employ nucleic acid probes are provided. Said methods produce staining patterns that can be tailored for specific cytogenetic analyzes. Said probes are appropriate for in situ hybridization and stain both interphase and metaphase chromosomal material with reliable signals. The nucleic acid probes are typically of a complexity greater than 50 kb, the complexity depending upon the cytogenetic application. Methods and reagents are provided for the detection of genetic rearrangements. Probes and test kits are provided for use in detecting genetic rearrangements, particularly for use in tumor cytogenetics, in the detection of disease related loci, specifically cancer, such as chronic myelogenous leukemia (CML) and for biological dosimetry. Methods and reagents are described for cytogenetic research, for the differentiation of cytogenetically similar but genetically different diseases, and for many prognostic and diagnostic applications.

  5. Allele-Specific Chromatin Recruitment and Therapeutic Vulnerabilities of ESR1 Activating Mutations.

    Science.gov (United States)

    Jeselsohn, Rinath; Bergholz, Johann S; Pun, Matthew; Cornwell, MacIntosh; Liu, Weihan; Nardone, Agostina; Xiao, Tengfei; Li, Wei; Qiu, Xintao; Buchwalter, Gilles; Feiglin, Ariel; Abell-Hart, Kayley; Fei, Teng; Rao, Prakash; Long, Henry; Kwiatkowski, Nicholas; Zhang, Tinghu; Gray, Nathanael; Melchers, Diane; Houtman, Rene; Liu, X Shirley; Cohen, Ofir; Wagle, Nikhil; Winer, Eric P; Zhao, Jean; Brown, Myles

    2018-02-12

    Estrogen receptor α (ER) ligand-binding domain (LBD) mutations are found in a substantial number of endocrine treatment-resistant metastatic ER-positive (ER + ) breast cancers. We investigated the chromatin recruitment, transcriptional network, and genetic vulnerabilities in breast cancer models harboring the clinically relevant ER mutations. These mutants exhibit both ligand-independent functions that mimic estradiol-bound wild-type ER as well as allele-specific neomorphic properties that promote a pro-metastatic phenotype. Analysis of the genome-wide ER binding sites identified mutant ER unique recruitment mediating the allele-specific transcriptional program. Genetic screens identified genes that are essential for the ligand-independent growth driven by the mutants. These studies provide insights into the mechanism of endocrine therapy resistance engendered by ER mutations and potential therapeutic targets. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. Genome-wide survey of allele-specific splicing in humans

    Directory of Open Access Journals (Sweden)

    Scheffler Konrad

    2008-06-01

    Full Text Available Abstract Background Accurate mRNA splicing depends on multiple regulatory signals encoded in the transcribed RNA sequence. Many examples of mutations within human splice regulatory regions that alter splicing qualitatively or quantitatively have been reported and allelic differences in mRNA splicing are likely to be a common and important source of phenotypic diversity at the molecular level, in addition to their contribution to genetic disease susceptibility. However, because the effect of a mutation on the efficiency of mRNA splicing is often difficult to predict, many mutations that cause disease through an effect on splicing are likely to remain undiscovered. Results We have combined a genome-wide scan for sequence polymorphisms likely to affect mRNA splicing with analysis of publicly available Expressed Sequence Tag (EST and exon array data. The genome-wide scan uses published tools and identified 30,977 SNPs located within donor and acceptor splice sites, branch points and exonic splicing enhancer elements. For 1,185 candidate splicing polymorphisms the difference in splicing between alternative alleles was corroborated by publicly available exon array data from 166 lymphoblastoid cell lines. We developed a novel probabilistic method to infer allele-specific splicing from EST data. The method uses SNPs and alternative mRNA isoforms mapped to EST sequences and models both regulated alternative splicing as well as allele-specific splicing. We have also estimated heritability of splicing and report that a greater proportion of genes show evidence of splicing heritability than show heritability of overall gene expression level. Our results provide an extensive resource that can be used to assess the possible effect on splicing of human polymorphisms in putative splice-regulatory sites. Conclusion We report a set of genes showing evidence of allele-specific splicing from an integrated analysis of genomic polymorphisms, EST data and exon array

  7. Quantitative threefold allele-specific PCR (QuanTAS-PCR) for highly sensitive JAK2 V617F mutant allele detection

    International Nuclear Information System (INIS)

    Zapparoli, Giada V; Jorissen, Robert N; Hewitt, Chelsee A; McBean, Michelle; Westerman, David A; Dobrovic, Alexander

    2013-01-01

    The JAK2 V617F mutation is the most frequent somatic change in myeloproliferative neoplasms, making it an important tumour-specific marker for diagnostic purposes and for the detection of minimal residual disease. Sensitive quantitative assays are required for both applications, particularly for the monitoring of minimal residual disease, which requires not only high sensitivity but also very high specificity. We developed a highly sensitive probe-free quantitative mutant-allele detection method, Quantitative Threefold Allele-Specific PCR (QuanTAS-PCR), that is performed in a closed-tube system, thus eliminating the manipulation of PCR products. QuantTAS-PCR uses a threefold approach to ensure allele-specific amplification of the mutant sequence: (i) a mutant allele-specific primer, (ii) a 3′dideoxy blocker to suppress false-positive amplification from the wild-type template and (iii) a PCR specificity enhancer, also to suppress false-positive amplification from the wild-type template. Mutant alleles were quantified relative to exon 9 of JAK2. We showed that the addition of the 3′dideoxy blocker suppressed but did not eliminate false-positive amplification from the wild-type template. However, the addition of the PCR specificity enhancer near eliminated false-positive amplification from the wild-type allele. Further discrimination between true and false positives was enabled by using the quantification cycle (Cq) value of a single mutant template as a cut-off point, thus enabling robust distinction between true and false positives. As 10,000 JAK2 templates were used per replicate, the assay had a sensitivity of 1/10 -4 per replicate. Greater sensitivity could be reached by increasing the number of replicates analysed. Variation in replicates when low mutant-allele templates were present necessitated the use of a statistics-based approach to estimate the load of mutant JAK2 copies. QuanTAS-PCR showed comparable quantitative results when validated against a

  8. Detection of MPL mutations by a novel allele-specific PCR-based strategy.

    Science.gov (United States)

    Furtado, Larissa V; Weigelin, Helmut C; Elenitoba-Johnson, Kojo S J; Betz, Bryan L

    2013-11-01

    MPL mutation testing is recommended in patients with suspected primary myelofibrosis or essential thrombocythemia who lack the JAK2 V617F mutation. MPL mutations can occur at allelic levels below 15%, which may escape detection by commonly used mutation screening methods such as Sanger sequencing. We developed a novel multiplexed allele-specific PCR assay capable of detecting most recurrent MPL exon 10 mutations associated with primary myelofibrosis and essential thrombocythemia (W515L, W515K, W515A, and S505N) down to a sensitivity of 2.5% mutant allele. Test results were reviewed from 15 reference cases and 1380 consecutive specimens referred to our laboratory for testing. Assay performance was compared to Sanger sequencing across a series of 58 specimens with MPL mutations. Positive cases consisted of 45 with W515L, 6 with S505N, 5 with W515K, 1 with W515A, and 1 with both W515L and S505N. Seven cases had mutations below 5% that were undetected by Sanger sequencing. Ten additional cases had mutation levels between 5% and 15% that were not consistently detected by sequencing. All results were easily interpreted in the allele-specific test. This assay offers a sensitive and reliable solution for MPL mutation testing. Sanger sequencing appears insufficiently sensitive for robust MPL mutation detection. Our data also suggest the relative frequency of S505N mutations may be underestimated, highlighting the necessity for inclusion of this mutation in MPL test platforms. Copyright © 2013 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

  9. Origin of specific chromosome aberration in radiation-induced leukemia

    International Nuclear Information System (INIS)

    Ban, Nobuhiko; Kai, Michiaki; Masuno, Yoko

    2005-01-01

    The theme in the title is discussed from the four aspects of specific chromosome aberration (sAb) patterns in radiation-induced leukemia (RIL), possibility for radiation to induce the sAb in RIL, any evidence for participation of delayed aberration to form sAb and the proportion of such healthy humans as having the specifically rearranged genome. Data of sAb observed in leukemia of 25 A-bomb survivors and of 38 patients post radiotherapy of cancers give a rather common pattern. However, many inconsistent results are obtained for sAb in patients post radiotherapy, A-bomb survivors, residents living in radio-contaminated houses in Taipei, in vitro exposure, and Chernobyl residents. At present, any clear evidence is available neither for sAb derived from the delayed aberration nor for estimating the proportion with the specifically rearranged gene. As above, it is unlikely that radiation induces such a translocation abnormality as BCR-ABL specifically seen in leukemia, and this aspect will be important for studies on the genesis of RIL and its risk assessment. (S.I.)

  10. Consequences for diversity when animals are prioritized for conservation of the whole genome or of one specific allele

    NARCIS (Netherlands)

    Engelsma, K.A.; Veerkamp, R.F.; Calus, M.P.L.; Windig, J.J.

    2014-01-01

    When animals are selected for one specific allele, for example for inclusion in a gene bank, this may result in the loss of diversity in other parts of the genome. The aim of this study was to quantify the risk of losing diversity across the genome when targeting a single allele for conservation

  11. Aberrant allele-specific replication, independent of parental origin, in blood cells of cancer patients

    International Nuclear Information System (INIS)

    Dotan, Zohar A; Dotan, Aviva; Ramon, Jacob; Avivi, Lydia

    2008-01-01

    Allelic counterparts of biallelically expressed genes display an epigenetic symmetry normally manifested by synchronous replication, different from genes subjected to monoallelic expression, which normally are characterized by an asynchronous mode of replication (well exemplified by the SNRPN imprinted locus). Malignancy was documented to be associated with gross modifications in the inherent replication-timing coordination between allelic counterparts of imprinted genes as well as of biallelically expressed loci. The cancer-related allelic replication timing aberrations are non-disease specific and appear in peripheral blood cells of cancer patients, including those with solid tumors. As such they offer potential blood markers for non-invasive cancer test. The present study was aimed to gain some insight into the mechanism leading to the replication timing alterations of genes in blood lymphocytes of cancer patients. Peripheral blood samples derived from patients with prostate cancer were chosen to represent the cancerous status, and samples taken from patients with no cancer but with benign prostate hyperplasia were used to portray the normal status. Fluorescence In Situ Hybridization (FISH) replication assay, applied to phytohemagglutinin (PHA)-stimulated blood lymphocytes, was used to evaluate the temporal order (either synchronous or asynchronous) of genes in the patients' cells. We demonstrated that: (i) the aberrant epigenetic profile, as delineated by the cancer status, is a reversible modification, evidenced by our ability to restore the normal patterns of replication in three unrelated loci (CEN15, SNRPN and RB1) by introducing an archetypical demethylating agent, 5-azacytidine; (ii) following the rehabilitating effect of demethylation, an imprinted gene (SNRPN) retains its original parental imprint; and (iii) the choice of an allele between early or late replication in the aberrant asynchronous replication, delineated by the cancer status, is not

  12. A genome-wide screen in human embryonic stem cells reveals novel sites of allele-specific histone modification associated with known disease loci

    LENUS (Irish Health Repository)

    Prendergast, James G D

    2012-05-19

    AbstractBackgroundChromatin structure at a given site can differ between chromosome copies in a cell, and such imbalances in chromatin structure have been shown to be important in understanding the molecular mechanisms controlling several disease loci. Human genetic variation, DNA methylation, and disease have been intensely studied, uncovering many sites of allele-specific DNA methylation (ASM). However, little is known about the genome-wide occurrence of sites of allele-specific histone modification (ASHM) and their relationship to human disease. The aim of this study was to investigate the extent and characteristics of sites of ASHM in human embryonic stem cells (hESCs).ResultsUsing a statistically rigorous protocol, we investigated the genomic distribution of ASHM in hESCs, and their relationship to sites of allele-specific expression (ASE) and DNA methylation. We found that, although they were rare, sites of ASHM were substantially enriched at loci displaying ASE. Many were also found at known imprinted regions, hence sites of ASHM are likely to be better markers of imprinted regions than sites of ASM. We also found that sites of ASHM and ASE in hESCs colocalize at risk loci for developmental syndromes mediated by deletions, providing insights into the etiology of these disorders.ConclusionThese results demonstrate the potential importance of ASHM patterns in the interpretation of disease loci, and the protocol described provides a basis for similar studies of ASHM in other cell types to further our understanding of human disease susceptibility.

  13. Rapid ABO genotyping by high-speed droplet allele-specific PCR using crude samples.

    Science.gov (United States)

    Taira, Chiaki; Matsuda, Kazuyuki; Takeichi, Naoya; Furukawa, Satomi; Sugano, Mitsutoshi; Uehara, Takeshi; Okumura, Nobuo; Honda, Takayuki

    2018-01-01

    ABO genotyping has common tools for personal identification of forensic and transplantation field. We developed a new method based on a droplet allele-specific PCR (droplet-AS-PCR) that enabled rapid PCR amplification. We attempted rapid ABO genotyping using crude DNA isolated from dried blood and buccal cells. We designed allele-specific primers for three SNPs (at nucleotides 261, 526, and 803) in exons 6 and 7 of the ABO gene. We pretreated dried blood and buccal cells with proteinase K, and obtained crude DNAs without DNA purification. Droplet-AS-PCR allowed specific amplification of the SNPs at the three loci using crude DNA, with results similar to those for DNA extracted from fresh peripheral blood. The sensitivity of the methods was 5%-10%. The genotyping of extracted DNA and crude DNA were completed within 8 and 9 minutes, respectively. The genotypes determined by the droplet-AS-PCR method were always consistent with those obtained by direct sequencing. The droplet-AS-PCR method enabled rapid and specific amplification of three SNPs of the ABO gene from crude DNA treated with proteinase K. ABO genotyping by the droplet-AS-PCR has the potential to be applied to various fields including a forensic medicine and transplantation medical care. © 2017 Wiley Periodicals, Inc.

  14. Linkage of familial Alzheimer disease to chromosome 14 in two large early-onset pedigrees: effects of marker allele frequencies on lod scores.

    Science.gov (United States)

    Nechiporuk, A; Fain, P; Kort, E; Nee, L E; Frommelt, E; Polinsky, R J; Korenberg, J R; Pulst, S M

    1993-05-01

    Alzheimer disease (AD) is a devastating neurodegenerative disease leading to global dementia. In addition to sporadic forms of AD, familial forms (FAD) have been recognized. Mutations in the amyloid precursor protein (APP) gene on chromosome (CHR) 21 have been shown to cause early-onset AD in a small number of pedigrees. Recently, linkage to markers on CHR 14 has been established in several early-onset FAD pedigrees. We now report lod scores for CHR 14 markers in two large early-onset FAD pedigrees. Pairwise linkage analysis suggested that in these pedigrees the mutation is tightly linked to the loci D14S43 and D14S53. However, assumptions regarding marker allele frequencies had a major and often unpredictable effect on calculated lod scores. Therefore, caution needs to be exercised when single pedigrees are analyzed with marker allele frequencies determined from the literature or from a pool of spouses.

  15. Identification of Mitosis-Specific Phosphorylation in Mitotic Chromosome-Associated Proteins.

    Science.gov (United States)

    Ohta, Shinya; Kimura, Michiko; Takagi, Shunsuke; Toramoto, Iyo; Ishihama, Yasushi

    2016-09-02

    During mitosis, phosphorylation of chromosome-associated proteins is a key regulatory mechanism. Mass spectrometry has been successfully applied to determine the complete protein composition of mitotic chromosomes, but not to identify post-translational modifications. Here, we quantitatively compared the phosphoproteome of isolated mitotic chromosomes with that of chromosomes in nonsynchronized cells. We identified 4274 total phosphorylation sites and 350 mitosis-specific phosphorylation sites in mitotic chromosome-associated proteins. Significant mitosis-specific phosphorylation in centromere/kinetochore proteins was detected, although the chromosomal association of these proteins did not change throughout the cell cycle. This mitosis-specific phosphorylation might play a key role in regulation of mitosis. Further analysis revealed strong dependency of phosphorylation dynamics on kinase consensus patterns, thus linking the identified phosphorylation sites to known key mitotic kinases. Remarkably, chromosomal axial proteins such as non-SMC subunits of condensin, TopoIIα, and Kif4A, together with the chromosomal periphery protein Ki67 involved in the establishment of the mitotic chromosomal structure, demonstrated high phosphorylation during mitosis. These findings suggest a novel mechanism for regulation of chromosome restructuring in mitosis via protein phosphorylation. Our study generated a large quantitative database on protein phosphorylation in mitotic and nonmitotic chromosomes, thus providing insights into the dynamics of chromatin protein phosphorylation at mitosis onset.

  16. Allele-specific gene expression in a wild nonhuman primate population

    Science.gov (United States)

    Tung, J.; Akinyi, M. Y.; Mutura, S.; Altmann, J.; Wray, G. A.; Alberts, S. C.

    2015-01-01

    Natural populations hold enormous potential for evolutionary genetic studies, especially when phenotypic, genetic and environmental data are all available on the same individuals. However, untangling the genotype-phenotype relationship in natural populations remains a major challenge. Here, we describe results of an investigation of one class of phenotype, allele-specific gene expression (ASGE), in the well-studied natural population of baboons of the Amboseli basin, Kenya. ASGE measurements identify cases in which one allele of a gene is overexpressed relative to the alternative allele of the same gene, within individuals, thus providing a control for background genetic and environmental effects. Here, we characterize the incidence of ASGE in the Amboseli baboon population, focusing on the genetic and environmental contributions to ASGE in a set of eleven genes involved in immunity and defence. Within this set, we identify evidence for common ASGE in four genes. We also present examples of two relationships between cis-regulatory genetic variants and the ASGE phenotype. Finally, we identify one case in which this relationship is influenced by a novel gene-environment interaction. Specifically, the dominance rank of an individual’s mother during its early life (an aspect of that individual’s social environment) influences the expression of the gene CCL5 via an interaction with cis-regulatory genetic variation. These results illustrate how environmental and ecological data can be integrated into evolutionary genetic studies of functional variation in natural populations. They also highlight the potential importance of early life environmental variation in shaping the genetic architecture of complex traits in wild mammals. PMID:21226779

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

    Science.gov (United States)

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

    2015-01-01

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

  18. Genetic recombination variation in wild Robertsonian mice: on the role of chromosomal fusions and Prdm9 allelic background

    OpenAIRE

    Capilla, Laia; Medarde, Nuria; Alemany-Schmidt, Alexandra; Oliver-Bonet, Maria; Ventura, Jacint; Ruiz-Herrera, Aurora

    2014-01-01

    Despite the existence of formal models to explain how chromosomal rearrangements can be fixed in a population in the presence of gene flow, few empirical data are available regarding the mechanisms by which genome shuffling contributes to speciation, especially in mammals. In order to shed light on this intriguing evolutionary process, here we present a detailed empirical study that shows how Robertsonian (Rb) fusions alter the chromosomal distribution of recombination events during the forma...

  19. Mapping of the human APOB gene to chromosome 2p and demonstration of a two-allele restriction fragment length polymorphism

    International Nuclear Information System (INIS)

    Huang, L.; Miller, D.A.; Bruns, G.A.P.; Breslow, J.L.

    1986-01-01

    ApoB is a large glycoprotein with an apparent molecular mass of 550 kDa on NaDodSO 4 /PAGE. Recently, apoB cDNA clones have been isolated from an expression library made with mRNA from a human hepatoma cell line. These clones, which were all 1.5-1.6 kilobases (kb) long and corresponded to the 3' end of apoB mRNA, were used to demonstrate that hepatic apoB mRNA is ≅ 22 kb long. In the current report, a probe derived from one of these cDNA clones, pB8, was used for in situ hybridization experiments to map the human gene for apoB, APOB, to the distal half of the short arm of chromosome 2. This probe was also used to analyze somatic cell hybrids and, in agreement with the in situ hybridization studies, concordancy was demonstrated with chromosome 2. In addition, two hybrids with chromosome 2 translocations that contain only the short arm reacted with the pB8 probe. A third hybrid with a complex rearrangement of chromosome 2, which deleted an interstitial region and the tip of the short arm of chromosome 2, did not react. These data indicate that APOB maps to either 2p21-p23 or 2p24-pter. In further studies, DNA from normal individuals, digested with the restriction endonuclease EcoRI and subjected to Southern blot analysis with the pB8 probe, revealed a two-allele restriction fragment length polymorphism (RFLP). The mapping studies provide the means for understanding the relationship of the APOB locus to others in the human genome, whereas the demonstration of an APOB RFLP increases their ability to assess the role of this locus in determining plasma lipoprotein levels

  20. Cloning and comparative mapping of a human chromosome 4-specific alpha satellite DNA sequence

    Energy Technology Data Exchange (ETDEWEB)

    D' Aiuto, L.; Marzella, R.; Archidiacono, N.; Rocchi, M. (Universita di Bari (Italy)); Antonacci, R. (Instituto Anatomia Umana Normale, Modena (Italy))

    1993-11-01

    The authors have isolated and characterized two human alphoid DNA clones: p4n1/4 and pZ4.1. Clone p4n1/4 identifies specifically the centromeric region of chromosome 4; pZ4.1 recognizes a subset of alphoid DNA shared by chromosomes 4 and 9. The specificity was determined using fluorescence in situ hybridization experiments on metaphase spreads and Southern blotting analysis of human-hamster somatic cell hybrids. The genomic organization of both subsets was also investigated. Comparative mapping on chimpanzee and gorilla chromosomes was performed. p4n1/4 hybridizes to chimpanzee chromosomes 11 and 13, homologs of human chromosomes 9 and 2q, respectively. On gorilla metaphase spreads, p4n1/4 hybridizes exclusively to the centromeric region of chromosome 19, partially homologous to human chromosome 17. No hybridization signal was detected on chromosome 3 of both chimpanzee and gorilla, in both species homolog of human chromosome 4. Identical comparative mapping results were obtained using pZ4.1 probe, although the latter recognizes an alphoid subset distinct from the one recognized by p4n1/4. The implications of these results in the evolution of centromeric regions of primate chromosomes are discussed. 33 refs., 4 figs.

  1. Chromosomal location and gene paucity of the male specific region on papaya Y chromosome

    Czech Academy of Sciences Publication Activity Database

    Yu, Q.; Hou, S.; Hobza, Roman; Feltus, F.A.; Wang, X.; Jin, W.; Skelton, R.L.; Blas, A.; Lemke, C.; Saw, J.H.; Moore, P.H.; Alam, M.; Jiang, J.; Paterson, A.H.; Vyskot, Boris; Ming, R.

    2007-01-01

    Roč. 278, č. 2 (2007), s. 177-185 ISSN 1617-4615 R&D Projects: GA ČR(CZ) GA521/06/0056 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : Carica papaya * repetitive sequences * sex chromosome Subject RIV: BO - Biophysics Impact factor: 2.978, year: 2007

  2. Allelic loss of the short arm of chromosome 4 in neuroblastoma suggests a novel tumour suppressor gene locus

    NARCIS (Netherlands)

    Caron, H.; van Sluis, P.; Buschman, R.; Pereira do Tanque, R.; Maes, P.; Beks, L.; de Kraker, J.; Voûte, P. A.; Vergnaud, G.; Westerveld, A.; Slater, R.; Versteeg, R.

    1996-01-01

    Neuroblastoma is a childhood neural crest tumour, genetically characterized by frequent deletions of the short arm of chromosome 1 and amplification of N-myc. Here we report the first evidence for a neuroblastoma tumour suppressor locus on 4pter. Cytogenetically we demonstrated rearrangements of 4p

  3. Kinetic characterisation of primer mismatches in allele-specific PCR: a quantitative assessment.

    Science.gov (United States)

    Waterfall, Christy M; Eisenthal, Robert; Cobb, Benjamin D

    2002-12-20

    A novel method of estimating the kinetic parameters of Taq DNA polymerase during rapid cycle PCR is presented. A model was constructed using a simplified sigmoid function to represent substrate accumulation during PCR in combination with the general equation describing high substrate inhibition for Michaelis-Menten enzymes. The PCR progress curve was viewed as a series of independent reactions where initial rates were accurately measured for each cycle. Kinetic parameters were obtained for allele-specific PCR (AS-PCR) amplification to examine the effect of mismatches on amplification. A high degree of correlation was obtained providing evidence of substrate inhibition as a major cause of the plateau phase that occurs in the later cycles of PCR.

  4. Radiation hybrids from human chromosome 3: A basis for the construction of region and specific sublibraries

    International Nuclear Information System (INIS)

    Atchison, L.; Cosmis, R.L.; Atchison, M.L.

    1990-01-01

    The authors are interested in identifying genes on human chromosome involved in disease processes. To date at least 20 different loci on this chromosome are implicated with various disease states. DNA libraries containing clones derived from a small chromosomal subregion implicated in a particular disease would greatly assist these studies. They have utilized the radiation hybrid (RH) technique to generate a series of somatic cell hybrids that contain small segments of human chromosome 3 as the only human genetic material. A Chinese hamster-human cell hybrid (Q314-2) containing only human chromosome 3 was used to prepare radiation hybrids. Cells were lethally X-irradiated with 6,000 rads and fused to Urd(??) Chinese hamster cells by PEG 1000 treatment. The majority of hybrids (>72%) analyzed retained portions of chromosome 3. The amount of chromosome 3 in each hybrid ranged from nearly all of the chromosome to very little. Currently these hybrids are being further characterized with single copy probes of known map location in order to isolate regions of chromosome 3 that contain specific disease locus. These reduced hybrids can then be used for the construction of region specific libraries and for the generation of new DNA probes from the specific region of interest

  5. Evidence of activity-specific, radial organization of mitotic chromosomes in Drosophila.

    Directory of Open Access Journals (Sweden)

    Yuri G Strukov

    2011-01-01

    Full Text Available The organization and the mechanisms of condensation of mitotic chromosomes remain unsolved despite many decades of efforts. The lack of resolution, tight compaction, and the absence of function-specific chromatin labels have been the key technical obstacles. The correlation between DNA sequence composition and its contribution to the chromosome-scale structure has been suggested before; it is unclear though if all DNA sequences equally participate in intra- or inter-chromatin or DNA-protein interactions that lead to formation of mitotic chromosomes and if their mitotic positions are reproduced radially. Using high-resolution fluorescence microscopy of live or minimally perturbed, fixed chromosomes in Drosophila embryonic cultures or tissues expressing MSL3-GFP fusion protein, we studied positioning of specific MSL3-binding sites. Actively transcribed, dosage compensated Drosophila genes are distributed along the euchromatic arm of the male X chromosome. Several novel features of mitotic chromosomes have been observed. MSL3-GFP is always found at the periphery of mitotic chromosomes, suggesting that active, dosage compensated genes are also found at the periphery of mitotic chromosomes. Furthermore, radial distribution of chromatin loci on mitotic chromosomes was found to be correlated with their functional activity as judged by core histone modifications. Histone modifications specific to active chromatin were found peripheral with respect to silent chromatin. MSL3-GFP-labeled chromatin loci become peripheral starting in late prophase. In early prophase, dosage compensated chromatin regions traverse the entire width of chromosomes. These findings suggest large-scale internal rearrangements within chromosomes during the prophase condensation step, arguing against consecutive coiling models. Our results suggest that the organization of mitotic chromosomes is reproducible not only longitudinally, as demonstrated by chromosome-specific banding

  6. Maternal age-specific risk of non-chromosomal anomalies

    NARCIS (Netherlands)

    Loane, M.; Dolk, H.; Morris, Joan K.

    To determine the excess risk of non-chromosomal congenital anomaly (NCA) among teenage mothers and older mothers. Population-based prevalence study using data from EUROCAT congenital anomaly registers in 23 regions of Europe in 15 countries, covering a total of 1.75 million births from 2000 to 2004.

  7. Maternal age-specific risk of non-chromosomal anomalies

    DEFF Research Database (Denmark)

    Loane, M; Dolk, H; Morris, J K

    2009-01-01

    OBJECTIVES: To determine the excess risk of non-chromosomal congenital anomaly (NCA) among teenage mothers and older mothers. DESIGN AND SETTING: Population-based prevalence study using data from EUROCAT congenital anomaly registers in 23 regions of Europe in 15 countries, covering a total of 1.7...

  8. Defective replication initiation results in locus specific chromosome breakage and a ribosomal RNA deficiency in yeast.

    Directory of Open Access Journals (Sweden)

    Joseph C Sanchez

    2017-10-01

    Full Text Available A form of dwarfism known as Meier-Gorlin syndrome (MGS is caused by recessive mutations in one of six different genes (ORC1, ORC4, ORC6, CDC6, CDT1, and MCM5. These genes encode components of the pre-replication complex, which assembles at origins of replication prior to S phase. Also, variants in two additional replication initiation genes have joined the list of causative mutations for MGS (Geminin and CDC45. The identity of the causative MGS genetic variants strongly suggests that some aspect of replication is amiss in MGS patients; however, little evidence has been obtained regarding what aspect of chromosome replication is faulty. Since the site of one of the missense mutations in the human ORC4 alleles is conserved between humans and yeast, we sought to determine in what way this single amino acid change affects the process of chromosome replication, by introducing the comparable mutation into yeast (orc4Y232C. We find that yeast cells with the orc4Y232C allele have a prolonged S-phase, due to compromised replication initiation at the ribosomal DNA (rDNA locus located on chromosome XII. The inability to initiate replication at the rDNA locus results in chromosome breakage and a severely reduced rDNA copy number in the survivors, presumably helping to ensure complete replication of chromosome XII. Although reducing rDNA copy number may help ensure complete chromosome replication, orc4Y232C cells struggle to meet the high demand for ribosomal RNA synthesis. This finding provides additional evidence linking two essential cellular pathways-DNA replication and ribosome biogenesis.

  9. Defective replication initiation results in locus specific chromosome breakage and a ribosomal RNA deficiency in yeast.

    Science.gov (United States)

    Sanchez, Joseph C; Kwan, Elizabeth X; Pohl, Thomas J; Amemiya, Haley M; Raghuraman, M K; Brewer, Bonita J

    2017-10-01

    A form of dwarfism known as Meier-Gorlin syndrome (MGS) is caused by recessive mutations in one of six different genes (ORC1, ORC4, ORC6, CDC6, CDT1, and MCM5). These genes encode components of the pre-replication complex, which assembles at origins of replication prior to S phase. Also, variants in two additional replication initiation genes have joined the list of causative mutations for MGS (Geminin and CDC45). The identity of the causative MGS genetic variants strongly suggests that some aspect of replication is amiss in MGS patients; however, little evidence has been obtained regarding what aspect of chromosome replication is faulty. Since the site of one of the missense mutations in the human ORC4 alleles is conserved between humans and yeast, we sought to determine in what way this single amino acid change affects the process of chromosome replication, by introducing the comparable mutation into yeast (orc4Y232C). We find that yeast cells with the orc4Y232C allele have a prolonged S-phase, due to compromised replication initiation at the ribosomal DNA (rDNA) locus located on chromosome XII. The inability to initiate replication at the rDNA locus results in chromosome breakage and a severely reduced rDNA copy number in the survivors, presumably helping to ensure complete replication of chromosome XII. Although reducing rDNA copy number may help ensure complete chromosome replication, orc4Y232C cells struggle to meet the high demand for ribosomal RNA synthesis. This finding provides additional evidence linking two essential cellular pathways-DNA replication and ribosome biogenesis.

  10. Ortholog Alleles at Xa3/Xa26 Locus Confer Conserved Race-Specific Resistance against Xanthomonas oryzae in Rice

    Institute of Scientific and Technical Information of China (English)

    Hong-Jing Li; Xiang-Hua Li; Jing-Hua Xiao; Rod A. Wing; Shi-Ping Wang

    2012-01-01

    The rice disease resistance (R) gene Xa3/Xa26 (having also been named Xa3 and Xa26) against Xanthomonas oryzae pv.oryzae (Xoo),which causes bacterial blight disease,belongs to a multiple gene family clustered in chromosome 11 and is from an AA genome rice cultivar (Oryza sativa L.).This family encodes leucine-rich repeat (LRR) receptor kinasetype proteins.Here,we show that the orthologs (alleles) of Xa3/Xa26,Xa3/Xa26-2,and Xa3/Xa26-3,from wild Oryza species O.officinalis (CC genome) and O.minuta (BBCC genome),respectively,were also R genes against Xoo.Xa3/Xa26-2 and Xa3/Xa26-3 conferred resistance to 16 of the 18 Xoo strains examined.Comparative sequence analysis of the Xa3/Xa26 families in the two wild Oryza species showed that Xa3/Xa26-3 appeared to have originated from the CC genome of O.minuta.The predicted proteins encoded by Xa3/Xa26,Xa3/Xa26-2,and Xa3/Xa26-3 share 91-99% sequence identity and 94-99% sequence similarity.Transgenic plants carrying a single copy of Xa3/Xa26,Xa3/Xa26-2,or Xa3/Xa26-3,in the same genetic background,showed a similar resistance spectrum to a set of Xoo strains,although plants carrying Xa3/Xa26-2 or Xa3/Xa26-3 showed lower resistance levels than the plants carrying Xa3/Xa26.These results suggest that the Xa3/Xa26 locus predates the speciation of A and C genome,which is approximately 7.5 million years ago.Thus,the resistance specificity of this locus has been conserved for a long time.

  11. Protocol for chromosome-specific probe construction using PRINS, micromanipulation and DOP-PCR techniques

    Directory of Open Access Journals (Sweden)

    PAULO Z. PASSAMANI

    2017-12-01

    Full Text Available ABSTRACT Chromosome-specific probes have been widely used in molecular cytogenetics, being obtained with different methods. In this study, a reproducible protocol for construction of chromosome-specific probes is proposed which associates in situ amplification (PRINS, micromanipulation and degenerate oligonucleotide-primed PCR (DOP-PCR. Human lymphocyte cultures were used to obtain metaphases from male and female individuals. The chromosomes were amplified via PRINS, and subcentromeric fragments of the X chromosome were microdissected using microneedles coupled to a phase contrast microscope. The fragments were amplified by DOP-PCR and labeled with tetramethyl-rhodamine-5-dUTP. The probes were used in fluorescent in situ hybridization (FISH procedure to highlight these specific regions in the metaphases. The results show one fluorescent red spot in male and two in female X chromosomes and interphase nuclei.

  12. Development of chromosome-arm-specific microsatellite markers in Triticum aestivum (Poaceae) using NGS technology

    Czech Academy of Sciences Publication Activity Database

    Nie, X.; Li, B.; Wang, L.; Liu, P.; Biradar, S. S.; Li, T.; Doležel, Jaroslav; Edwards, D.; Luo, M.; Weining, S.

    2012-01-01

    Roč. 99, č. 9 (2012), e369-e371 ISSN 0002-9122 Institutional research plan: CEZ:AV0Z50380511 Keywords : chromosome-arm-specific DNA * flow-sorted chromosomes * next-generation sequencing Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.586, year: 2012

  13. Typing for HLA-DPB1*03 and HLA-DPB1*06 using allele-specific DNA in vitro amplification and allele-specific oligonucleotide probes. Detection of "new" DPB1*06 variants

    DEFF Research Database (Denmark)

    Fugger, L; Morling, N; Ryder, L P

    1989-01-01

    DP gene typing using in vitro DNA amplification combined with sequence-specific oligonucleotide probes has recently been reported. The resulting DNA amplification was specific for the HLA-DPB locus. Typing for the individual DPB alleles was exclusively dependent on the hybridizations of the probe...

  14. Physical and transcript map of the region between D6S264 and D6S149 on chromosome 6q27, the minimal region of allele loss in sporadic epithelial ovarian cancer

    DEFF Research Database (Denmark)

    Liu, Ying; Emilion, Gracy; Mungall, Andrew J

    2002-01-01

    We have previously shown a high frequency of allele loss at D6S193 (62%) on chromosomal arm 6q27 in ovarian tumours and mapped the minimal region of allele loss between D6S297 and D6S264 (3 cM). We isolated and mapped a single non-chimaeric YAC (17IA12, 260-280 kb) containing D6S193 and D6S297...

  15. Allele-specific expression at the androgen receptor alpha gene in a hybrid unisexual fish, the Amazon molly (Poecilia formosa.

    Directory of Open Access Journals (Sweden)

    Fangjun Zhu

    Full Text Available The all-female Amazon molly (Poecilia formosa is the result of a hybridization of the Atlantic molly (P. mexicana and the sailfin molly (P. latipinna approximately 120,000 years ago. As a gynogenetic species, P. formosa needs to copulate with heterospecific males including males from one of its bisexual ancestral species. However, the sperm only triggers embryogenesis of the diploid eggs. The genetic information of the sperm donor typically will not contribute to the next generation of P. formosa. Hence, P. formosa possesses generally one allele from each of its ancestral species at any genetic locus. This raises the question whether both ancestral alleles are equally expressed in P. formosa. Allele-specific expression (ASE has been previously assessed in various organisms, e.g., human and fish, and ASE was found to be important in the context of phenotypic variability and disease. In this study, we utilized Real-Time PCR techniques to estimate ASE of the androgen receptor alpha (arα gene in several distinct tissues of Amazon mollies. We found an allelic bias favoring the maternal ancestor (P. mexicana allele in ovarian tissue. This allelic bias was not observed in the gill or the brain tissue. Sequencing of the promoter regions of both alleles revealed an association between an Indel in a known CpG island and differential expression. Future studies may reveal whether our observed cis-regulatory divergence is caused by an ovary-specific trans-regulatory element, preferentially activating the allele of the maternal ancestor.

  16. [Molecular authentication of Jinyinhua formula granule by using allele-specific PCR].

    Science.gov (United States)

    Jiang, Chao; Tu, Li-Chan; Yuan, Yuan; Huang, Lu-Qi; Gao, Wei; Jin, Yan

    2017-07-01

    Traditional authentication method is hard to identify herb's authenticity of traditional Chinese medicine(TCM) formula granules because they have lost all their morphological characteristics. In this study, a new allele-specific PCR method was established for identifying the authentication of Jinyinhua formula granule (made from Lonicerae Japonicae Flos) based on an SNP site in trnL-trnF fragment. Genomic DNA was successfully extracted from Lonicerae Japonicae Flos and its formula granules by using an improved spin column method and then PCR was performed with the designed primer. Approximately 110 bp specific bands was obtained only in the authentic Lonicerae Japonicae Flos and its formula granules, while no bands were found in fake mixed products. In addition, the PCR product sequence was proved from Lonicerae Japonicae Flos trnL-trnF sequence by using BLAST method. Therefore, DNA molecular authentication method could make up the limitations of character identification method and microscopic identification, and quickly identify herb's authenticity of TCM formula granules, with enormous potential for market supervision and quality control. Copyright© by the Chinese Pharmaceutical Association.

  17. The neurological mouse mutations jittery and hesitant are allelic and map to the region of mouse chromosome 10 homologous to 19p13.3

    Energy Technology Data Exchange (ETDEWEB)

    Kapfhamer, D.; Sufalko, D.; Warren, S. [Univ. of Michigan, Ann Arbor, MI (United States)] [and others

    1996-08-01

    Jittery (ji) is a recessive mouse mutation on Chromosome 10 characterized by progressive ataxic gait, dystonic movements, spontaneus seizures, and death by dehydration/starvation before fertility. Recently, a viable neurological recessive mutation, hesitant, was discovered. It is characterized by hesitant, uncoordinated movements, exaggerated stepping of the hind limbs, and reduced fertility in males. In a complementation test and by genetic mapping we have shown here that hesitant and jittery are allelic. Using several large intersubspecific backcrosses and intercrosses we have genetically mapped ji near the marker Amh and microsatellite markers D10Mit7, D10Mit21, and D10Mit23. The linked region of mouse Chromosome 10 is homologous to human 19p13.3, to which several human ataxia loci have recently been mapped. By excluding genes that map to human 21q22.3 (Pfkl) and 12q23 (Nfyb), we conclude that jittery is not likely to be a genetic mouse model for human Unverricht-Lundborg progressive myoclonus epilepsy (EPM1) on 21q22.3 nor for spinocerebellar ataxia II (SCA2) on 12q22-q24. The closely linked markers presented here will facilitate positional cloning of the ji gene. 31 refs., 2 figs.

  18. Technical aspects of typing for HLA-DP alleles using allele-specific DNA in vitro amplification and sequence-specific oligonucleotide probes. Detection of single base mismatches

    DEFF Research Database (Denmark)

    Fugger, L; Morling, N; Ryder, L P

    1990-01-01

    The polymerase chain reaction (PCR) is an effective method for in vitro DNA amplification which combined with probing with synthetic oligonucleotides can be used for, e.g., HLA-typing. We have studied the technical aspects of HLA-DP typing with the technique. DNA from mononuclear nucleated cells...... was extracted with either a simple salting out method or phenol/chloroform. Both DNAs could be readily used for PCR. The MgC2 concentration of the PCR buffer and the annealing temperature of the thermal cycle of the PCR were the two most important variables. The MgCl2 concentration and the temperature must...... be carefully titrated for each primer pair in the PCR. The influence of mismatches between the primer and the DNA template were studied and we found that, by using primers differing only from each other at the 3' end, cross-amplification of closely homologous alleles could be avoided. Thus, single base...

  19. Allele specific LAMP- gold nanoparticle for characterization of single nucleotide polymorphisms

    Directory of Open Access Journals (Sweden)

    Fábio Ferreira Carlos

    2017-12-01

    Full Text Available Due to their relevance as disease biomarkers and for diagnostics, screening of single nucleotide polymorphism (SNPs requires simple and straightforward strategies capable to provide results in medium throughput settings. Suitable approaches relying on isothermal amplification techniques have been evolving to substitute the cumbersome and highly specialized PCR amplification detection schemes. Nonetheless, identification of an individual’s genotype still requires sophisticated equipment and laborious methods.Here, we present a low-cost and reliable approach based on the allele specific loop-mediated isothermal amplification (AS-LAMP coupled to ssDNA functionalized gold nanoparticle (Au-nanoprobe colorimetric sequence discrimination. The Au-nanoprobe integration allows for the colorimetric detection of AS-LAMP amplification product that can be easily interpreted in less than 15 min. We targeted a clinical relevant SNP responsible for lactose intolerance (-13910C/T dbSNP rs#: 4988235 to demonstrate its proof of concept and full potential of this novel approach. Keywords: SNP, Isothermal amplification, Gold nanoparticles, Gold nanoprobes, Lactose intolerance

  20. Allele-specific DNA methylation of disease susceptibility genes in Japanese patients with inflammatory bowel disease.

    Science.gov (United States)

    Chiba, Hirofumi; Kakuta, Yoichi; Kinouchi, Yoshitaka; Kawai, Yosuke; Watanabe, Kazuhiro; Nagao, Munenori; Naito, Takeo; Onodera, Motoyuki; Moroi, Rintaro; Kuroha, Masatake; Kanazawa, Yoshitake; Kimura, Tomoya; Shiga, Hisashi; Endo, Katsuya; Negoro, Kenichi; Nagasaki, Masao; Unno, Michiaki; Shimosegawa, Tooru

    2018-01-01

    Inflammatory bowel disease (IBD) has an unknown etiology; however, accumulating evidence suggests that IBD is a multifactorial disease influenced by a combination of genetic and environmental factors. The influence of genetic variants on DNA methylation in cis and cis effects on expression have been demonstrated. We hypothesized that IBD susceptibility single-nucleotide polymorphisms (SNPs) regulate susceptibility gene expressions in cis by regulating DNA methylation around SNPs. For this, we determined cis-regulated allele-specific DNA methylation (ASM) around IBD susceptibility genes in CD4+ effector/memory T cells (Tem) in lamina propria mononuclear cells (LPMCs) in patients with IBD and examined the association between the ASM SNP genotype and neighboring susceptibility gene expressions. CD4+ effector/memory T cells (Tem) were isolated from LPMCs in 15 Japanese IBD patients (ten Crohn's disease [CD] and five ulcerative colitis [UC] patients). ASM analysis was performed by methylation-sensitive SNP array analysis. We defined ASM as a changing average relative allele score ([Formula: see text]) >0.1 after digestion by methylation-sensitive restriction enzymes. Among SNPs showing [Formula: see text] >0.1, we extracted the probes located on tag-SNPs of 200 IBD susceptibility loci and around IBD susceptibility genes as candidate ASM SNPs. To validate ASM, bisulfite-pyrosequencing was performed. Transcriptome analysis was examined in 11 IBD patients (seven CD and four UC patients). The relation between rs36221701 genotype and neighboring gene expressions were analyzed. We extracted six candidate ASM SNPs around IBD susceptibility genes. The top of [Formula: see text] (0.23) was rs1130368 located on HLA-DQB1. ASM around rs36221701 ([Formula: see text] = 0.14) located near SMAD3 was validated using bisulfite pyrosequencing. The SMAD3 expression was significantly associated with the rs36221701 genotype (p = 0.016). We confirmed the existence of cis-regulated ASM around

  1. Allele-specific DNA methylation of disease susceptibility genes in Japanese patients with inflammatory bowel disease

    Science.gov (United States)

    Chiba, Hirofumi; Kakuta, Yoichi; Kinouchi, Yoshitaka; Kawai, Yosuke; Watanabe, Kazuhiro; Nagao, Munenori; Naito, Takeo; Onodera, Motoyuki; Moroi, Rintaro; Kuroha, Masatake; Kanazawa, Yoshitake; Kimura, Tomoya; Shiga, Hisashi; Endo, Katsuya; Negoro, Kenichi; Nagasaki, Masao; Unno, Michiaki; Shimosegawa, Tooru

    2018-01-01

    Background Inflammatory bowel disease (IBD) has an unknown etiology; however, accumulating evidence suggests that IBD is a multifactorial disease influenced by a combination of genetic and environmental factors. The influence of genetic variants on DNA methylation in cis and cis effects on expression have been demonstrated. We hypothesized that IBD susceptibility single-nucleotide polymorphisms (SNPs) regulate susceptibility gene expressions in cis by regulating DNA methylation around SNPs. For this, we determined cis-regulated allele-specific DNA methylation (ASM) around IBD susceptibility genes in CD4+ effector/memory T cells (Tem) in lamina propria mononuclear cells (LPMCs) in patients with IBD and examined the association between the ASM SNP genotype and neighboring susceptibility gene expressions. Methods CD4+ effector/memory T cells (Tem) were isolated from LPMCs in 15 Japanese IBD patients (ten Crohn's disease [CD] and five ulcerative colitis [UC] patients). ASM analysis was performed by methylation-sensitive SNP array analysis. We defined ASM as a changing average relative allele score (ΔRAS¯) >0.1 after digestion by methylation-sensitive restriction enzymes. Among SNPs showing ΔRAS¯ >0.1, we extracted the probes located on tag-SNPs of 200 IBD susceptibility loci and around IBD susceptibility genes as candidate ASM SNPs. To validate ASM, bisulfite-pyrosequencing was performed. Transcriptome analysis was examined in 11 IBD patients (seven CD and four UC patients). The relation between rs36221701 genotype and neighboring gene expressions were analyzed. Results We extracted six candidate ASM SNPs around IBD susceptibility genes. The top of ΔRAS¯ (0.23) was rs1130368 located on HLA-DQB1. ASM around rs36221701 (ΔRAS¯ = 0.14) located near SMAD3 was validated using bisulfite pyrosequencing. The SMAD3 expression was significantly associated with the rs36221701 genotype (p = 0.016). Conclusions We confirmed the existence of cis-regulated ASM around IBD

  2. Microsatellite and single nucleotide polymorphisms in the β-globin locus control region-hypersensitive Site 2: SPECIFICITY of Tunisian βs chromosomes.

    Science.gov (United States)

    Ben Mustapha, Maha; Moumni, Imen; Zorai, Amine; Douzi, Kaïs; Ghanem, Abderraouf; Abbes, Salem

    2012-01-01

    The diversity of sickle cell disease severity is attributed to several cis acting factors, among them the single nucleotide polymorphisms (SNPs) and (AT) rich region in the β-locus control region (β-LCR). This contains five DNase I hypersensitive sites (HS) located 6 to 22 kb upstream to the ϵ gene. The most important of these is the HS2 (5' β-LCR-HS2), characterized by the presence of three different SNPs and a microsatellite region known to be in association with β(S) chromosomes in various populations. The aim of this study was to present the molecular investigation of the 5' β-LCR-HS2 site in normal and sickle cell disease individuals in order to determine if there is any correlation or specificity between these molecular markers, the β(S) Tunisian chromosomes and phenotypical expression of sickle cell disease. One hundred and twenty-four chromosomes from Tunisian individuals (49 β(S) carriers and 13 normal individuals) were screened by polymerase chain reaction (PCR) and sequencing for the polymorphic short tandem microsatellite repeats (AT)(X)N(12)(AT)(Y) and the three SNPs (rs7119428, rs9736333 and rs60240093) of the 5' β-LCR-HS2. Twelve configurations of the microsatellite motif were found with an ancestral configuration elaborated by ClustalW software. Normal and mutated alleles were observed at the homozygous and heterozygous states for the three SNPs. Correlation between microsatellites and SNPs suggests that mutant SNP alleles were mainly associated, in the homozygous sickle cell disease phenotype, with the (AT)(8)N(12)GT(AT)(7) configuration, whereas, normal SNP alleles were associated with the (AT)(X)N(12)(AT)(11) configurations in normal β(A) chromosomes. The correlation of these various configurations with Hb F expression was also investigated. The principal component analysis (PCA) showed the correlation between the homozygous sickle cell disease phenotype, mutated SNP alleles and the Benin microsatellite configuration (AT)(8)N(12)GT

  3. Use of allele-specific FAIRE to determine functional regulatory polymorphism using large-scale genotyping arrays.

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    Andrew J P Smith

    Full Text Available Following the widespread use of genome-wide association studies (GWAS, focus is turning towards identification of causal variants rather than simply genetic markers of diseases and traits. As a step towards a high-throughput method to identify genome-wide, non-coding, functional regulatory variants, we describe the technique of allele-specific FAIRE, utilising large-scale genotyping technology (FAIRE-gen to determine allelic effects on chromatin accessibility and regulatory potential. FAIRE-gen was explored using lymphoblastoid cells and the 50,000 SNP Illumina CVD BeadChip. The technique identified an allele-specific regulatory polymorphism within NR1H3 (coding for LXR-α, rs7120118, coinciding with a previously GWAS-identified SNP for HDL-C levels. This finding was confirmed using FAIRE-gen with the 200,000 SNP Illumina Metabochip and verified with the established method of TaqMan allelic discrimination. Examination of this SNP in two prospective Caucasian cohorts comprising 15,000 individuals confirmed the association with HDL-C levels (combined beta = 0.016; p = 0.0006, and analysis of gene expression identified an allelic association with LXR-α expression in heart tissue. Using increasingly comprehensive genotyping chips and distinct tissues for examination, FAIRE-gen has the potential to aid the identification of many causal SNPs associated with disease from GWAS.

  4. Porphyromonas gingivalis Uses Specific Domain Rearrangements and Allelic Exchange to Generate Diversity in Surface Virulence Factors.

    Science.gov (United States)

    Dashper, Stuart G; Mitchell, Helen L; Seers, Christine A; Gladman, Simon L; Seemann, Torsten; Bulach, Dieter M; Chandry, P Scott; Cross, Keith J; Cleal, Steven M; Reynolds, Eric C

    2017-01-01

    Porphyromonas gingivalis is a keystone pathogen of chronic periodontitis. The virulence of P. gingivalis is reported to be strain related and there are currently a number of strain typing schemes based on variation in capsular polysaccharide, the major and minor fimbriae and adhesin domains of Lys-gingipain (Kgp), amongst other surface proteins. P. gingivalis can exchange chromosomal DNA between strains by natural competence and conjugation. The aim of this study was to determine the genetic variability of P. gingivalis strains sourced from international locations over a 25-year period and to determine if variability in surface virulence factors has a phylogenetic basis. Whole genome sequencing was performed on 13 strains and comparison made to 10 previously sequenced strains. A single nucleotide polymorphism-based phylogenetic analysis demonstrated a shallow tri-lobed phylogeny. There was a high level of reticulation in the phylogenetic network, demonstrating extensive horizontal gene transfer between the strains. Two highly conserved variants of the catalytic domain of the major virulence factor the Kgp proteinase (Kgp cat I and Kgp cat II) were found. There were three variants of the fourth Kgp C-terminal cleaved adhesin domain. Specific variants of the cell surface proteins FimA, FimCDE, MfaI, RagAB, Tpr, and PrtT were also identified. The occurrence of all these variants in the P. gingivalis strains formed a mosaic that was not related to the SNP-based phylogeny. In conclusion P. gingivalis uses domain rearrangements and genetic exchange to generate diversity in specific surface virulence factors.

  5. High-specificity detection of rare alleles with Paired-End Low Error Sequencing (PELE-Seq).

    Science.gov (United States)

    Preston, Jessica L; Royall, Ariel E; Randel, Melissa A; Sikkink, Kristin L; Phillips, Patrick C; Johnson, Eric A

    2016-06-14

    Polymorphic loci exist throughout the genomes of a population and provide the raw genetic material needed for a species to adapt to changes in the environment. The minor allele frequencies of rare Single Nucleotide Polymorphisms (SNPs) within a population have been difficult to track with Next-Generation Sequencing (NGS), due to the high error rate of standard methods such as Illumina sequencing. We have developed a wet-lab protocol and variant-calling method that identifies both sequencing and PCR errors, called Paired-End Low Error Sequencing (PELE-Seq). To test the specificity and sensitivity of the PELE-Seq method, we sequenced control E. coli DNA libraries containing known rare alleles present at frequencies ranging from 0.2-0.4 % of the total reads. PELE-Seq had higher specificity and sensitivity than standard libraries. We then used PELE-Seq to characterize rare alleles in a Caenorhabditis remanei nematode worm population before and after laboratory adaptation, and found that minor and rare alleles can undergo large changes in frequency during lab-adaptation. We have developed a method of rare allele detection that mitigates both sequencing and PCR errors, called PELE-Seq. PELE-Seq was evaluated using control E. coli populations and was then used to compare a wild C. remanei population to a lab-adapted population. The PELE-Seq method is ideal for investigating the dynamics of rare alleles in a broad range of reduced-representation sequencing methods, including targeted amplicon sequencing, RAD-Seq, ddRAD, and GBS. PELE-Seq is also well-suited for whole genome sequencing of mitochondria and viruses, and for high-throughput rare mutation screens.

  6. High degree of sex chromosome differentiation in stickleback fishes

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    Shimada Yukinori

    2011-09-01

    Full Text Available Abstract Background Studies of closely related species with different sex chromosome systems can provide insights into the processes of sex chromosome differentiation and evolution. To investigate the potential utility of molecular markers in studying sex chromosome differentiation at early stages of their divergence, we examined the levels and patterns of genetic differentiation between sex chromosomes in nine-spined (Pungitius pungitius and three-spined sticklebacks (Gasterosteus aculeatus using microsatellite markers. Results A set of novel microsatellite markers spanning the entire length of the sex chromosomes were developed for nine-spined sticklebacks using the sequenced genomes of other fish species. Sex-specific patterns of genetic variability and male-specific alleles were identified at most of these loci, indicating a high degree of differentiation between the X and Y chromosomes in nine-spined sticklebacks. In three-spined sticklebacks, male-specific alleles were detected at some loci confined to two chromosomal regions. In addition, male-specific null alleles were identified at several other loci, implying the absence of Y chromosomal alleles at these loci. Overall, male-specific alleles and null alleles were found over a region spanning 81% of the sex chromosomes in three-spined sticklebacks. Conclusions High levels but distinct patterns of sex chromosome differentiation were uncovered in the stickleback species that diverged 13 million years ago. Our results suggest that the Y chromosome is highly degenerate in three-spined sticklebacks, but not in nine-spined sticklebacks. In general, the results demonstrate that microsatellites can be useful in identifying the degree and patterns of sex chromosome differentiation in species at initial stages of sex chromosome evolution.

  7. High-throughput analysis of candidate imprinted genes and allele-specific gene expression in the human term placenta

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    Clark Taane G

    2010-04-01

    Full Text Available Abstract Background Imprinted genes show expression from one parental allele only and are important for development and behaviour. This extreme mode of allelic imbalance has been described for approximately 56 human genes. Imprinting status is often disrupted in cancer and dysmorphic syndromes. More subtle variation of gene expression, that is not parent-of-origin specific, termed 'allele-specific gene expression' (ASE is more common and may give rise to milder phenotypic differences. Using two allele-specific high-throughput technologies alongside bioinformatics predictions, normal term human placenta was screened to find new imprinted genes and to ascertain the extent of ASE in this tissue. Results Twenty-three family trios of placental cDNA, placental genomic DNA (gDNA and gDNA from both parents were tested for 130 candidate genes with the Sequenom MassArray system. Six genes were found differentially expressed but none imprinted. The Illumina ASE BeadArray platform was then used to test 1536 SNPs in 932 genes. The array was enriched for the human orthologues of 124 mouse candidate genes from bioinformatics predictions and 10 human candidate imprinted genes from EST database mining. After quality control pruning, a total of 261 informative SNPs (214 genes remained for analysis. Imprinting with maternal expression was demonstrated for the lymphocyte imprinted gene ZNF331 in human placenta. Two potential differentially methylated regions (DMRs were found in the vicinity of ZNF331. None of the bioinformatically predicted candidates tested showed imprinting except for a skewed allelic expression in a parent-specific manner observed for PHACTR2, a neighbour of the imprinted PLAGL1 gene. ASE was detected for two or more individuals in 39 candidate genes (18%. Conclusions Both Sequenom and Illumina assays were sensitive enough to study imprinting and strong allelic bias. Previous bioinformatics approaches were not predictive of new imprinted genes

  8. Differential ACE expression among tissues in allele-specific Wistar rat lines

    NARCIS (Netherlands)

    Kamilic, Jelena; Lely, A. Titia; van Goor, Harry; Buikema, Hendrik; Tent, Hilde; Navis, Gerjan J.; Korstanje, Ron

    In humans, the insertion/deletion polymorphism in the angiotensin converting enzyme (ACE) gene accounts for half of the variance in plasma ACE activity. The deletion allele is associated with high plasma ACE activity, cardiovascular disease, and renal disease. In rat, a similar association is found

  9. Modeling Chromosomes

    Science.gov (United States)

    Robertson, Carol

    2016-01-01

    Learning about chromosomes is standard fare in biology classrooms today. However, students may find it difficult to understand the relationships among the "genome", "chromosomes", "genes", a "gene locus", and "alleles". In the simple activity described in this article, which follows the 5E approach…

  10. Development of allele-specific multiplex PCR to determine the length of poly-T in intron 8 of CFTR

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    Neng Chen

    2014-07-01

    Full Text Available Cystic fibrosis transmembrane conductance regulator (CFTR gene mutation analysis has been implemented for Cystic Fibrosis (CF carrier screening, and molecular diagnosis of CF and congenital bilateral absence of the vas deferens (CBAVD. Although poly-T allele analysis in intron 8 of CFTR is required when a patient is positive for R117H, it is not recommended for routine carrier screening. Therefore, commercial kits for CFTR mutation analysis were designed either to mask the poly-T allele results, unless a patient is R117H positive, or to have the poly-T analysis as a standalone reflex test using the same commercial platform. There are other standalone assays developed to detect poly-T alleles, such as heteroduplex analysis, High Resolution Melting (HRM curve analysis, allele-specific PCR (AS-PCR and Sanger sequencing. In this report, we developed a simple and easy-to-implement multiplex AS-PCR assay using unlabeled standard length primers, which can be used as a reflex or standalone test for CFTR poly-T track analysis. Out of 115 human gDNA samples tested, results from our new AS-PCR matched to the previous known poly-T results or results from Sanger sequencing.

  11. Allele-Specific DNA Methylation and Its Interplay with Repressive Histone Marks at Promoter-Mutant TERT Genes

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    Josh Lewis Stern

    2017-12-01

    Full Text Available A mutation in the promoter of the Telomerase Reverse Transcriptase (TERT gene is the most frequent noncoding mutation in cancer. The mutation drives unusual monoallelic expression of TERT, allowing immortalization. Here, we find that DNA methylation of the TERT CpG island (CGI is also allele-specific in multiple cancers. The expressed allele is hypomethylated, which is opposite to cancers without TERT promoter mutations. The continued presence of Polycomb repressive complex 2 (PRC2 on the inactive allele suggests that histone marks of repressed chromatin may be causally linked to high DNA methylation. Consistent with this hypothesis, TERT promoter DNA containing 5-methyl-CpG has much increased affinity for PRC2 in vitro. Thus, CpG methylation and histone marks appear to collaborate to maintain the two TERT alleles in different epigenetic states in TERT promoter mutant cancers. Finally, in several cancers, DNA methylation levels at the TERT CGI correlate with altered patient survival.

  12. Allele-Specific DNA Methylation and Its Interplay with Repressive Histone Marks at Promoter-Mutant TERT Genes.

    Science.gov (United States)

    Stern, Josh Lewis; Paucek, Richard D; Huang, Franklin W; Ghandi, Mahmoud; Nwumeh, Ronald; Costello, James C; Cech, Thomas R

    2017-12-26

    A mutation in the promoter of the Telomerase Reverse Transcriptase (TERT) gene is the most frequent noncoding mutation in cancer. The mutation drives unusual monoallelic expression of TERT, allowing immortalization. Here, we find that DNA methylation of the TERT CpG island (CGI) is also allele-specific in multiple cancers. The expressed allele is hypomethylated, which is opposite to cancers without TERT promoter mutations. The continued presence of Polycomb repressive complex 2 (PRC2) on the inactive allele suggests that histone marks of repressed chromatin may be causally linked to high DNA methylation. Consistent with this hypothesis, TERT promoter DNA containing 5-methyl-CpG has much increased affinity for PRC2 in vitro. Thus, CpG methylation and histone marks appear to collaborate to maintain the two TERT alleles in different epigenetic states in TERT promoter mutant cancers. Finally, in several cancers, DNA methylation levels at the TERT CGI correlate with altered patient survival. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  13. Allele-specific Gene Silencing of Mutant mRNA Restores Cellular Function in Ullrich Congenital Muscular Dystrophy Fibroblasts

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    Satoru Noguchi

    2014-01-01

    Full Text Available Ullrich congenital muscular dystrophy (UCMD is an inherited muscle disorder characterized clinically by muscle weakness, distal joint hyperlaxity, and proximal joint contractures. Sporadic and recessive mutations in the three collagen VI genes, COL6A1, COL6A2, and COL6A3, are reported to be causative. In the sporadic forms, a heterozygous point mutation causing glycine substitution in the triple helical domain has been identified in higher rate. In this study, we examined the efficacy of siRNAs, which target point mutation site, on specific knockdown toward transcripts from mutant allele and evaluated consequent cellular phenotype of UCMD fibroblasts. We evaluated the effect of siRNAs targeted to silence-specific COL6A1 alleles in UCMD fibroblasts, where simultaneous expression of both wild-type and mutant collagen VI resulted in defective collagen localization. Addition of mutant-specific siRNAs allowed normal extracellular localization of collagen VI surrounding fibroblasts, suggesting selective inhibition of mutant collagen VI. Targeting the single-nucleotide COL6A1 c.850G>A (p.G284R mutation responsible a sporadic autosomal dominant form of UCMD can potently and selectively block expression of mutant collagen VI. These results suggest that allele-specific knockdown of the mutant mRNA can potentially be considered as a therapeutic procedure in UCMD due to COL6A1 point mutations.

  14. Dyslexia risk variant rs600753 is linked with dyslexia-specific differential allelic expression of DYX1C1

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    Bent Müller

    2018-02-01

    Full Text Available Abstract An increasing number of genetic variants involved in dyslexia development were discovered during the last years, yet little is known about the molecular functional mechanisms of these SNPs. In this study we investigated whether dyslexia candidate SNPs have a direct, disease-specific effect on local expression levels of the assumed target gene by using a differential allelic expression assay. In total, 12 SNPs previously associated with dyslexia and related phenotypes were suitable for analysis. Transcripts corresponding to four SNPs were sufficiently expressed in 28 cell lines originating from controls and a family affected by dyslexia. We observed a significant effect of rs600753 on expression levels of DYX1C1 in forward and reverse sequencing approaches. The expression level of the rs600753 risk allele was increased in the respective seven cell lines from members of the dyslexia family which might be due to a disturbed transcription factor binding sites. When considering our results in the context of neuroanatomical dyslexia-specific findings, we speculate that this mechanism may be part of the pathomechanisms underlying the dyslexia-specific brain phenotype. Our results suggest that allele-specific DYX1C1 expression levels depend on genetic variants of rs600753 and contribute to dyslexia. However, these results are preliminary and need replication.

  15. Specific Silencing of L392V PSEN1 Mutant Allele by RNA Interference

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    Malgorzata Sierant

    2011-01-01

    Full Text Available RNA interference (RNAi technology provides a powerful molecular tool to reduce an expression of selected genes in eukaryotic cells. Short interfering RNAs (siRNAs are the effector molecules that trigger RNAi. Here, we describe siRNAs that discriminate between the wild type and mutant (1174 C→G alleles of human Presenilin1 gene (PSEN1. This mutation, resulting in L392V PSEN1 variant, contributes to early onset familial Alzheimer's disease. Using the dual fluorescence assay, flow cytometry and fluorescent microscopy we identified positions 8th–11th, within the central part of the antisense strand, as the most sensitive to mismatches. 2-Thiouridine chemical modification introduced at the 3′-end of the antisense strand improved the allele discrimination, but wobble base pairing adjacent to the mutation site abolished the siRNA activity. Our data indicate that siRNAs can be designed to discriminate between the wild type and mutant alleles of genes that differ by just a single nucleotide.

  16. Identification and Genetic Diversity of Etambutol Resistant Strains of Mycobacterium Tuberculosis by Allelic-Specific PCR and Spologiotyping

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    Zahra Derakhshani Nezhad

    2012-09-01

    Full Text Available Background & Objectives: Ethambutol is one of the four main drugs in treatment of tuberculosis. The most common mutation associated with this drug resistance usually occurs in codon 306 of embB. The aim of this study was to detect ethambutol resistance using Allele-Specific PCR and Spoligotyping in various subtypes of Mycobacterium tuberculosis.   Methods : 140 sputum specimens were collected from suspected TB patients. They were digested and decontaminated using Pettrof method before culturing them on LJ medium. Drug susceptibility testing was performed on 106 culture positive specimens using proportional method. DNA was extracted from the isolated organisms and subsequently subjected to Allele-Specific PCR to detect any mutationin embB306. Spoligotyping was then used to determine the subtypes.   Results: Out of 106 cultures positive samples, 36 samples (33.9% showed resistance to ethambutol using proportional method. Allele-Specific PCR assay identified 93 as sensitive and 13 (27.6% as resistant strains. The results of PCR were in agreement with result of proportional method. The PCR method revealed that 61.5% of mutation occurred in the first and 38.5% in third nucleotides. Spoligotyping differentiated Mycobacterium tuberculosis strains into Beijing (10 9.4%, Bovis (2 1.8%, CAS (24 22.6%, EAI (1 0.9%, Haarlem (27 25.4%, LAM (5 4.7%, Manu (5 4.7%, T (27 25.4% and U( 2 1,8% families. The high frequency of mutation in embB gene was belonged to Haarlem, CAS and T subfamilies.   Conclusion: Based on results current study, mutations in the genes other than embB might have occurred in the resistant strains that gave negative result in Allele-Specific PCR assay. Therefore other mechanisms of resistance to this antibiotic should be investigated.

  17. Ploidy mosaicism and allele-specific gene expression differences in the allopolyploid Squalius alburnoides

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    Matos Isa

    2011-12-01

    Full Text Available Abstract Background Squalius alburnoides is an Iberian cyprinid fish resulting from an interspecific hybridisation between Squalius pyrenaicus females (P genome and males of an unknown Anaecypris hispanica-like species (A genome. S. alburnoides is an allopolyploid hybridogenetic complex, which makes it a likely candidate for ploidy mosaicism occurrence, and is also an interesting model to address questions about gene expression regulation and genomic interactions. Indeed, it was previously suggested that in S. alburnoides triploids (PAA composition silencing of one of the three alleles (mainly of the P allele occurs. However, not a whole haplome is inactivated but a more or less random inactivation of alleles varying between individuals and even between organs of the same fish was seen. In this work we intended to correlate expression differences between individuals and/or between organs to the occurrence of mosaicism, evaluating if mosaics could explain previous observations and its impact on the assessment of gene expression patterns. Results To achieve our goal, we developed flow cytometry and cell sorting protocols for this system generating more homogenous cellular and transcriptional samples. With this set-up we detected 10% ploidy mosaicism within the S. alburnoides complex, and determined the allelic expression profiles of ubiquitously expressed genes (rpl8; gapdh and β-actin in cells from liver and kidney of mosaic and non-mosaic individuals coming from different rivers over a wide geographic range. Conclusions Ploidy mosaicism occurs sporadically within the S. alburnoides complex, but in a frequency significantly higher than reported for other organisms. Moreover, we could exclude the influence of this phenomenon on the detection of variable allelic expression profiles of ubiquitously expressed genes (rpl8; gapdh and β-actin in cells from liver and kidney of triploid individuals. Finally, we determined that the expression patterns

  18. Infrequent detection of germline allele-specific expression of TGFBR1 in lymphoblasts and tissues of colon cancer patients.

    LENUS (Irish Health Repository)

    Guda, Kishore

    2009-06-15

    Recently, germline allele-specific expression (ASE) of the gene encoding for transforming growth factor-beta type I receptor (TGFBR1) has been proposed to be a major risk factor for cancer predisposition in the colon. Germline ASE results in a lowered expression of one of the TGFBR1 alleles (>1.5-fold), and was shown to occur in approximately 20% of informative familial and sporadic colorectal cancer (CRC) cases. In the present study, using the highly quantitative pyrosequencing technique, we estimated the frequency of ASE in TGFBR1 in a cohort of affected individuals from familial clusters of advanced colon neoplasias (cancers and adenomas with high-grade dysplasia), and also from a cohort of individuals with sporadic CRCs. Cases were considered positive for the presence of ASE if demonstrating an allelic expression ratio <0.67 or >1.5. Using RNA derived from lymphoblastoid cell lines, we find that of 46 informative Caucasian advanced colon neoplasia cases with a family history, only 2 individuals display a modest ASE, with allelic ratios of 1.65 and 1.73, respectively. Given that ASE of TGFBR1, if present, would likely be more pronounced in the colon compared with other tissues, we additionally determined the allele ratios of TGFBR1 in the RNA derived from normal-appearing colonic mucosa of sporadic CRC cases. We, however, found no evidence of ASE in any of 44 informative sporadic cases analyzed. Taken together, we find that germline ASE of TGFBR1, as assayed in lymphoblastoid and colon epithelial cells of colon cancer patients, is a relatively rare event.

  19. Construction of physical maps for the sex-specific regions of papaya sex chromosomes

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    Na Jong-Kuk

    2012-05-01

    Full Text Available Abstract Background Papaya is a major fruit crop in tropical and subtropical regions worldwide. It is trioecious with three sex forms: male, female, and hermaphrodite. Sex determination is controlled by a pair of nascent sex chromosomes with two slightly different Y chromosomes, Y for male and Yh for hermaphrodite. The sex chromosome genotypes are XY (male, XYh (hermaphrodite, and XX (female. The papaya hermaphrodite-specific Yh chromosome region (HSY is pericentromeric and heterochromatic. Physical mapping of HSY and its X counterpart is essential for sequencing these regions and uncovering the early events of sex chromosome evolution and to identify the sex determination genes for crop improvement. Results A reiterate chromosome walking strategy was applied to construct the two physical maps with three bacterial artificial chromosome (BAC libraries. The HSY physical map consists of 68 overlapped BACs on the minimum tiling path, and covers all four HSY-specific Knobs. One gap remained in the region of Knob 1, the only knob structure shared between HSY and X, due to the lack of HSY-specific sequences. This gap was filled on the physical map of the HSY corresponding region in the X chromosome. The X physical map consists of 44 BACs on the minimum tiling path with one gap remaining in the middle, due to the nature of highly repetitive sequences. This gap was filled on the HSY physical map. The borders of the non-recombining HSY were defined genetically by fine mapping using 1460 F2 individuals. The genetically defined HSY spanned approximately 8.5 Mb, whereas its X counterpart extended about 5.4 Mb including a 900 Kb region containing the Knob 1 shared by the HSY and X. The 8.5 Mb HSY corresponds to 4.5 Mb of its X counterpart, showing 4 Mb (89% DNA sequence expansion. Conclusion The 89% increase of DNA sequence in HSY indicates rapid expansion of the Yh chromosome after genetic recombination was suppressed 2–3 million years ago. The

  20. Sex chromosome differentiation and the W- and Z-specific loci in Xenopus laevis.

    Science.gov (United States)

    Mawaribuchi, Shuuji; Takahashi, Shuji; Wada, Mikako; Uno, Yoshinobu; Matsuda, Yoichi; Kondo, Mariko; Fukui, Akimasa; Takamatsu, Nobuhiko; Taira, Masanori; Ito, Michihiko

    2017-06-15

    Genetic sex-determining systems in vertebrates include two basic types of heterogamety; XX (female)/XY (male) and ZZ (male)/ZW (female) types. The African clawed frog Xenopus laevis has a ZZ/ZW-type sex-determining system. In this species, we previously identified a W-specific sex (female)-determining gene dmw, and specified W and Z chromosomes, which could be morphologically indistinguishable (homomorphic). In addition to dmw, we most recently discovered two genes, named scanw and ccdc69w, and one gene, named capn5z in the W- and Z-specific regions, respectively. In this study, we revealed the detail structures of the W/Z-specific loci and genes. Sequence analysis indicated that there is almost no sequence similarity between 278kb W-specific and 83kb Z-specific sequences on chromosome 2Lq32-33, where both the transposable elements are abundant. Synteny and phylogenic analyses indicated that all the W/Z-specific genes might have emerged independently. Expression analysis demonstrated that scanw and ccdc69w or capn5z are expressed in early differentiating ZW gonads or testes, thereby suggesting possible roles in female or male development, respectively. Importantly, the sex-determining gene (SDG) dmw might have been generated after allotetraploidization, thereby indicating the construction of the new sex-determining system by dmw after species hybridization. Furthermore, by direct genotyping, we confirmed that diploid WW embryos developed into normal female frogs, which indicate that the Z-specific region is not essential for female development. Overall, these findings indicate that sex chromosome differentiation has started, although no heteromorphic sex chromosomes are evident yet, in X. laevis. Homologous recombination suppression might have promoted the accumulation of mutations and transposable elements, and enlarged the W/Z-specific regions, thereby resulting in differentiation of the W/Z chromosomes. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Tissue-specific features of the X chromosome and nucleolus spatial dynamics in a malaria mosquito, Anopheles atroparvus.

    Science.gov (United States)

    Bondarenko, Semen M; Artemov, Gleb N; Sharakhov, Igor V; Stegniy, Vladimir N

    2017-01-01

    Spatial organization of chromosome territories is important for maintenance of genomic stability and regulation of gene expression. Recent studies have shown tissue-specific features of chromosome attachments to the nuclear envelope in various organisms including malaria mosquitoes. However, other spatial characteristics of nucleus organization, like volume and shape of chromosome territories, have not been studied in Anopheles. We conducted a thorough analysis of tissue-specific features of the X chromosome and nucleolus volume and shape in follicular epithelium and nurse cells of the Anopheles atroparvus ovaries using a modern open-source software. DNA of the polytene X chromosome from ovarian nurse cells was obtained by microdissection and was used as a template for amplification with degenerate oligo primers. A fluorescently labeled X chromosome painting probe was hybridized with formaldehyde-fixed ovaries of mosquitoes using a 3D-FISH method. The nucleolus was stained by immunostaining with an anti-fibrillarin antibody. The analysis was conducted with TANGO-a software for a chromosome spatial organization analysis. We show that the volume and position of the X chromosome have tissue-specific characteristics. Unlike nurse cell nuclei, the growth of follicular epithelium nuclei is not accompanied with the proportional growth of the X chromosome. However, the shape of the X chromosome does not differ between the tissues. The dynamics of the X chromosome attachment regions location is tissue-specific and it is correlated with the process of nucleus growth in follicular epithelium and nurse cells.

  2. Frequency Specific Effects of ApoE ε4 Allele on Resting-State Networks in Nondemented Elders

    Directory of Open Access Journals (Sweden)

    Ying Liang

    2017-01-01

    Full Text Available We applied resting-state functional magnetic resonance imaging (fMRI to examine the Apolipoprotein E (ApoE ε4 allele effects on functional connectivity of the default mode network (DMN and the salience network (SN. Considering the frequency specific effects of functional connectivity, we decomposed the brain network time courses into two bands: 0.01–0.027 Hz and 0.027–0.08 Hz. All scans were acquired by the Alzheimer’s Disease Neuroscience Initiative (ADNI. Thirty-two nondemented subjects were divided into two groups based on the presence (n=16 or absence (n=16 of the ApoE ε4 allele. We explored the frequency specific effects of ApoE ε4 allele on the default mode network (DMN and the salience network (SN functional connectivity. Compared to ε4 noncarriers, the DMN functional connectivity of ε4 carriers was significantly decreased while the SN functional connectivity of ε4 carriers was significantly increased. Many functional connectivities showed significant differences at the lower frequency band of 0.01–0.027 Hz or the higher frequency band of 0.027–0.08 Hz instead of the typical range of 0.01–0.08 Hz. The results indicated a frequency dependent effect of resting-state signals when investigating RSNs functional connectivity.

  3. Development of inter-specific chromosomes segment substitution libraries (CSSL) in rice

    Science.gov (United States)

    Six libraries of inter-specific Chromosome Segment Substitution Lines (CSSLs) of rice are being developed as pre-breeding materials and genetic stocks. Three accessions of O. rufipogon were selected as donors, based on phylogenetic, geographical and morphological divergence, and crossed with two rec...

  4. Centralspindlin and Chromosomal Passenger Complex Behavior During Normal and Rappaport Furrow Specification in Echinoderm Embryos

    Science.gov (United States)

    Argiros, Haroula; Henson, Lauren; Holguin, Christiana; Foe, Victoria; Shuster, Charles Bradley

    2014-01-01

    The chromosomal passenger (CPC) and Centralspindlin complexes are essential for organizing the anaphase central spindle and providing cues that position the cytokinetic furrow between daughter nuclei. However, echinoderm zygotes are also capable of forming “Rappaport furrows” between asters positioned back-to-back without intervening chromosomes. To understand how these complexes contribute to normal and Rappaport furrow formation, we studied the localization patterns of Survivin and mitotic-kinesin-like-protein1 (MKLP1), members respectively of the CPC and the Centralspindlin complex, and the effect of CPC inhibition on cleavage in mono- and binucleate echinoderm zygotes. In zygotes, Survivin initially localized to metaphase chromosomes, upon anaphase onset relocalized to the central spindle and then, together with MKLP1 spread towards the equatorial cortex in an Aurora-dependent manner. Inhibition of Aurora kinase activity resulted in disruption of central spindle organization and furrow regression, although astral microtubule elongation and furrow initiation were normal. In binucleate cells containing two parallel spindles MKLP1 and Survivin localized to the plane of the former metaphase plate, but were not observed in the secondary cleavage plane formed between unrelated spindle poles, except when chromosomes were abnormally present there. However, the secondary furrow was sensitive to Aurora inhibition, indicating that Aurora kinase may still contribute to furrow ingression without chromosomes nearby. Our results provide insights that reconcile classic micromanipulation studies with current molecular understanding of furrow specification in animal cells. PMID:22887753

  5. Data Mining Empowers the Generation of a Novel Class of Chromosome-specific DNA Probes

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Hui; Weier, Heinz-Ulrich G.; Kwan, Johnson; Wang, Mei; O' Brien, Benjamin

    2011-03-08

    Probes that allow accurate delineation of chromosome-specific DNA sequences in interphase or metaphase cell nuclei have become important clinical tools that deliver life-saving information about the gender or chromosomal make-up of a product of conception or the probability of an embryo to implant, as well as the definition of tumor-specific genetic signatures. Often such highly specific DNA probes are proprietary in nature and have been the result of extensive probe selection and optimization procedures. We describe a novel approach that eliminates costly and time consuming probe selection and testing by applying data mining and common bioinformatics tools. Similar to a rational drug design process in which drug-protein interactions are modeled in the computer, the rational probe design described here uses a set of criteria and publicly available bioinformatics software to select the desired probe molecules from libraries comprised of hundreds of thousands of probe molecules. Examples describe the selection of DNA probes for the human X and Y chromosomes, both with unprecedented performance, but in a similar fashion, this approach can be applied to other chromosomes or species.

  6. Genetic analysis of gamma-ray mutagenesis in yeast. II. Allele-specific control of mutagenesis

    International Nuclear Information System (INIS)

    McKee, R.H.; Lawrence, C.W.

    1979-01-01

    We find that partially different sets of gene functions are required for the production of different kinds of mutations induced by 60 Co γ rays in Saccharomyces cerevisiae. This observation is very similar to others made previously with respect to uv mutagenesis and confirms the conclusion that such distinctive patterns of genetic control reflect properties of the test alleles and their genetic locations, rather than the kinds of lesions required to revert them. The data also support the model of mutagenic repair outlined in the first paper of this series in which partially different sets of gene functions are required for the production of different kinds of mutations, the formation of mutations at different genetic sites and the induction of mutations by different mutagens

  7. Advantage of using allele-specific copy numbers when testing for association in regions with common copy number variants.

    Directory of Open Access Journals (Sweden)

    Gaëlle Marenne

    Full Text Available Copy number variants (CNV can be called from SNP-arrays; however, few studies have attempted to combine both CNV and SNP calls to test for association with complex diseases. Even when SNPs are located within CNVs, two separate association analyses are necessary, to compare the distribution of bi-allelic genotypes in cases and controls (referred to as SNP-only strategy and the number of copies of a region (referred to as CNV-only strategy. However, when disease susceptibility is actually associated with allele specific copy-number states, the two strategies may not yield comparable results, raising a series of questions about the optimal analytical approach. We performed simulations of the performance of association testing under different scenarios that varied genotype frequencies and inheritance models. We show that the SNP-only strategy lacks power under most scenarios when the SNP is located within a CNV; frequently it is excluded from analysis as it does not pass quality control metrics either because of an increased rate of missing calls or a departure from fitness for Hardy-Weinberg proportion. The CNV-only strategy also lacks power because the association testing depends on the allele which copy number varies. The combined strategy performs well in most of the scenarios. Hence, we advocate the use of this combined strategy when testing for association with SNPs located within CNVs.

  8. Impact of pre-existing MSP142-allele specific immunity on potency of an erythrocytic Plasmodium falciparum vaccine

    Directory of Open Access Journals (Sweden)

    Bergmann-Leitner Elke S

    2012-09-01

    Full Text Available Abstract Background MSP1 is the major surface protein on merozoites and a prime candidate for a blood stage malaria vaccine. Preclinical and seroepidemiological studies have implicated antibodies to MSP1 in protection against blood stage parasitaemia and/or reduced parasite densities, respectively. Malaria endemic areas have multiple strains of Plasmodium falciparum circulating at any given time, giving rise to complex immune responses, an issue which is generally not addressed in clinical trials conducted in non-endemic areas. A lack of understanding of the effect of pre-existing immunity to heterologous parasite strains may significantly contribute to vaccine failure in the field. The purpose of this study was to model the effect of pre-existing immunity to MSP142 on the immunogenicity of blood-stage malaria vaccines based on alternative MSP1 alleles. Methods Inbred and outbred mice were immunized with various recombinant P. falciparum MSP142 proteins that represent the two major alleles of MSP142, MAD20 (3D7 and Wellcome (K1, FVO. Humoral immune responses were analysed by ELISA and LuminexTM, and functional activity of induced MSP142-specific antibodies was assessed by growth inhibition assays. T-cell responses were characterized using ex vivo ELISpot assays. Results Analysis of the immune responses induced by various immunization regimens demonstrated a strong allele-specific response at the T cell level in both inbred and outbred mice. The success of heterologous regimens depended on the degree of homology of the N-terminal p33 portion of the MSP142, likely due to the fact that most T cell epitopes reside in this part of the molecule. Analysis of humoral immune responses revealed a marked cross-reactivity between the alleles. Functional analyses showed that some of the heterologous regimens induced antibodies with improved growth inhibitory activities. Conclusion The development of a more broadly efficacious MSP1 based vaccine may be

  9. Lack of specificity of chromosome breaks resulting from radiation-induced genomic instability in Chinese hamster cells

    International Nuclear Information System (INIS)

    Trott, K.-R.; Teibe, A.

    1998-01-01

    In V79 Chinese hamster cells, radiation-induced genomic instability results in a persistently increased frequency of micronuclei, dicentric chromosomes and apoptosis and in decreased colony-forming ability. These manifestations of radiation-induced genomic instability may be attributed to an increased rate of chromosome breakage events many generations after irradiation. This chromosomal instability does not seem to be a property which has been inflicted on individual chromosomes at the time of irradiation. Rather, it appears to be secondary to an increased level of non-specific clastogenic factors in the progeny of most if not all irradiated cells. This conclusion is drawn from the observations presented here, that all the chromosomes in surviving V79 cells are involved in the formation of dicentric chromosome aberrations 1 or 2 weeks after irradiation with about equal probability if corrections are made for chromosome length. (orig.)

  10. Identification of Bacillus anthracis specific chromosomal sequences by suppressive subtractive hybridization

    Directory of Open Access Journals (Sweden)

    Redkar Rajendra

    2004-02-01

    Full Text Available Abstract Background Bacillus anthracis, Bacillus thuringiensis and Bacillus cereus are closely related members of the B. cereus-group of bacilli. Suppressive subtractive hybridization (SSH was used to identify specific chromosomal sequences unique to B. anthracis. Results Two SSH libraries were generated. Genomic DNA from plasmid-cured B. anthracis was used as the tester DNA in both libraries, while genomic DNA from either B. cereus or B. thuringiensis served as the driver DNA. Progressive screening of the libraries by colony filter and Southern blot analyses identified 29 different clones that were specific for the B. anthracis chromosome relative not only to the respective driver DNAs, but also to seven other different strains of B. cereus and B. thuringiensis included in the process. The nucleotide sequences of the clones were compared with those found in genomic databases, revealing that over half of the clones were located into 2 regions on the B. anthracis chromosome. Conclusions Genes encoding potential cell wall synthesis proteins dominated one region, while bacteriophage-related sequences dominated the other region. The latter supports the hypothesis that acquisition of these bacteriophage sequences occurred during or after speciation of B. anthracis relative to B. cereus and B. thuringiensis. This study provides insight into the chromosomal differences between B. anthracis and its closest phylogenetic relatives.

  11. Y-chromosome-specific microsatellite mutation rates re-examined using a minisatellite, MSY1.

    Science.gov (United States)

    Jobling, M A; Heyer, E; Dieltjes, P; de Knijff, P

    1999-10-01

    Polymorphic Y-chromosome-specific microsatellites are becoming increasingly used in evolutionary and forensic studies and, in particular, in dating the origins of Y-chromosomal lineages. Previously, haplotyping of Y chromosomes from males belonging to a set of deep-rooting pedigrees was used to estimate a conservative average Y-chromosomal microsatellite mutation rate of 2.1 x 10(-3)per locus per generation. A number of males showed multiple differences in haplotypes compared with other males within their pedigrees, and these were excluded from the calculation of this estimate, on the grounds that non-paternity was a more probable explanation than multiple mutation within a lineage. Here we reanalyse the pedigrees using an independent highly polymorphic system, the Y-specific minisatellite, MSY1. This supports the hypothesis of non-paternity where more than one microsatellite difference was observed, provides further support for the previously deduced microsatellite mutation rate and throws light on the mutation dynamics of MSY1 itself, suggesting that single-step changes are not the only mode of mutation.

  12. Karyotypic relationships among Equus grevyi, Equus burchelli and domestic horse defined using horse chromosome arm-specific probes.

    Science.gov (United States)

    Musilova, P; Kubickova, S; Zrnova, E; Horin, P; Vahala, J; Rubes, J

    2007-01-01

    Using laser microdissection we prepared a set of horse chromosome arm-specific probes. Most of the probes were generated from horse chromosomes, some of them were derived from Equus zebra hartmannae. The set of probes were hybridized onto E. grevyi chromosomes in order to establish a genome-wide chromosomal correspondence between this zebra and horse. The use of arm-specific probes provided us with more information on the mutual arrangement of the genomes than we could obtain by means of whole-chromosome paints generated by flow sorting, even if we used reciprocal painting with probe sets from both species. By comparison of our results and results of comparative mapping in E. burchelli, we also established the chromosomal correspondence between E. grevyi and E. burchelli, providing evidence for a very close karyotypic relationship between these two zebra species. Establishment of the comparative map for E. grevyi contributes to the knowledge of the karyotypic phylogeny in the Equidae family.

  13. Frequencies of X-ray and fast neutron induced chromosome translocations in human peripheral blood lymphocytes as detected by in situ hybridization using chromosome specific DNA libraries

    International Nuclear Information System (INIS)

    Natarajan, A.T.; Darroudi, F.; Vermeulen, S.; Wiegant, J.

    1992-01-01

    DNA libraries of six human chromosomes were used to detect translocations in human lymphocytes induced by different doses of X-rays and fast neutrons. Results show that with X-rays, one can detect about 1.5 to 2.0 fold more translocations in comparison to dicentrics, whereas following fast neutron irradiation, the difference between these two classes of aberrations are significantly different at high doses. In addition, triple fluorescent in situ hybridization technique was used to study the frequencies of radiation-induced translocations involving a specific chromosome. Chromosome number 1 was found to be involved in translocations more frequently than chromosomes number 2, 3, 4, 8 and X. (author). 10 refs., 1 fig., 2 tabs

  14. A mitosis-specific and R loop-driven ATR pathway promotes faithful chromosome segregation.

    Science.gov (United States)

    Kabeche, Lilian; Nguyen, Hai Dang; Buisson, Rémi; Zou, Lee

    2018-01-05

    The ataxia telangiectasia mutated and Rad3-related (ATR) kinase is crucial for DNA damage and replication stress responses. Here, we describe an unexpected role of ATR in mitosis. Acute inhibition or degradation of ATR in mitosis induces whole-chromosome missegregation. The effect of ATR ablation is not due to altered cyclin-dependent kinase 1 (CDK1) activity, DNA damage responses, or unscheduled DNA synthesis but to loss of an ATR function at centromeres. In mitosis, ATR localizes to centromeres through Aurora A-regulated association with centromere protein F (CENP-F), allowing ATR to engage replication protein A (RPA)-coated centromeric R loops. As ATR is activated at centromeres, it stimulates Aurora B through Chk1, preventing formation of lagging chromosomes. Thus, a mitosis-specific and R loop-driven ATR pathway acts at centromeres to promote faithful chromosome segregation, revealing functions of R loops and ATR in suppressing chromosome instability. Copyright © 2018, American Association for the Advancement of Science.

  15. ABO alleles are linked with haplotypes of an erythroid cell-specific regulatory element in intron 1 with a few exceptions attributable to genetic recombination.

    Science.gov (United States)

    Nakajima, T; Sano, R; Takahashi, Y; Watanabe, K; Kubo, R; Kobayashi, M; Takahashi, K; Takeshita, H; Kominato, Y

    2016-01-01

    Recent investigation of transcriptional regulation of the ABO genes has identified a candidate erythroid cell-specific regulatory element, named the +5·8-kb site, in the first intron of ABO. Six haplotypes of the site have been reported previously. The present genetic population study demonstrated that each haplotype was mostly linked with specific ABO alleles with a few exceptions, possibly as a result of hybrid formation between common ABO alleles. Thus, investigation of these haplotypes could provide a clue to further elucidation of ABO alleles. © 2015 International Society of Blood Transfusion.

  16. Human Platelet Antigen Alleles in 998 Taiwanese Blood Donors Determined by Sequence-Specific Primer Polymerase Chain Reaction

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    Shun-Chung Pai

    2013-01-01

    Full Text Available Polymorphism of human platelet antigens (HPAs leads to alloimmunizations and immune-mediated platelet disorders including fetal-neonatal alloimmune thrombocytopenia (FNAIT, posttransfusion purpura (PTP, and platelet transfusion refractoriness (PTR. HPA typing and knowledge of antigen frequency in a population are important in particular for the provision of HPA-matched blood components for patients with PTR. We have performed allele genotyping for HPA-1 through -6 and -15 among 998 platelet donors from 6 blood centers in Taiwan using sequence-specific primer polymerase chain reaction. The HPA allele frequency was 99.55, and 0.45% for HPA-1a and -1b; 96.49, and 3.51% for HPA-2a and -2b; 55.81, and 44.19% for HPA-3a and -3b; 99.75, and 0.25% for HPA-4a and -4b; 98.50, and 1.50% for HPA-5a and -5b; 97.75 and 2.25% for HPA-6a and -6b; 53.71 and 46.29% for HPA-15a and -15b. HPA-15b and HPA-3a, may be considered the most important, followed by HPA-2, -6, -1, -5, and -4 systems, as a cause of FNAIT, PTP, and PTR based on allele frequency. HPA-4b and HPA-5b role cannot be excluded based on their immunogenicity. A larger-scale study will now be conducted to confirm these hypotheses and to establish an apheresis donor database for the procurement of HPA-matched apheresis platelets for patients with PTR.

  17. Allele-specific primer polymerase chain reaction for a single nucleotide polymorphism (C1205T) of swine Toll-like receptor 5 and comparison of the allelic frequency among several pig breeds in Japan and the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Muneta, Y.; Minagawa, Y.; Kusumoto, M.; Shinkai, H.; Uenishi, H.; Šplíchal, Igor

    2012-01-01

    Roč. 56, č. 6 (2012), s. 385-391 ISSN 0385-5600 R&D Projects: GA ČR GA524/09/0365 Institutional support: RVO:61388971 Keywords : allele-specific PCR * Salmonella enterica serovar Choleraesuis * single nucleotide polymorphism Subject RIV: EC - Immunology Impact factor: 1.545, year: 2012

  18. Detection of Turner syndrome using X-chromosome inactivation specific differentially methylated CpG sites: A pilot study.

    Science.gov (United States)

    Zhang, Qiang; Guo, Xiaohong; Tian, Tian; Wang, Teng; Li, Qiaoli; Wang, Lei; Liu, Yun; Xing, Qinghe; He, Lin; Zhao, Xinzhi

    2017-05-01

    Early diagnosis of Turner syndrome (TS) may improve preventive measures and treatment. X-chromosome inactivation specific differentially methylated CpG sites (XIDMSs) that are high methylated in inactive X chromosomes (Xi) and unmethylated in active X chromosomes (Xa) may be potential makers for TS detection. The candidate XIDMSs were screened from 9 male and 12 female DNA samples with normal karyotypes using the Illumina 450k array and validated by bisulfite sequencing PCR and pyrosequencing assay. X chromosome dosage was calculated according to the methylation level of multiple XIDMSs. Overall, 108 candidate XIDMSs were screened by the 450k array. Validations indicated that XIDMSs gathered and formed the X-chromosome inactivation specific differentially methylated regions (XIDMRs). Using 3 XIDMRs at SAT1, UXT and UTP14A loci, 36 TS, 22 normal female and 6 male samples were analyzed. Methylation levels of the 20 XIDMSs in the XIDMRs could distinguish between TS and normal female DNA samples, the X chromosome dosage was consistent with karyotyping data. Analyzing samples of 2 triple X syndrome and 3 Klinefelter syndrome patients suggested that this method could be used to detect X chromosome aneuploids other than TS. XIDMSs are widely spread along the X chromosome and might be effective markers for detection of TS and other X chromosome aneuploids. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. The male-specific region of the human Y chromosome is a mosaic of discrete sequence classes

    NARCIS (Netherlands)

    Skaletsky, Helen; Kuroda-Kawaguchi, Tomoko; Minx, Patrick J.; Cordum, Holland S.; Hillier, LaDeana; Brown, Laura G.; Repping, Sjoerd; Pyntikova, Tatyana; Ali, Johar; Bieri, Tamberlyn; Chinwalla, Asif; Delehaunty, Andrew; Delehaunty, Kim; Du, Hui; Fewell, Ginger; Fulton, Lucinda; Fulton, Robert; Graves, Tina; Hou, Shun-Fang; Latrielle, Philip; Leonard, Shawn; Mardis, Elaine; Maupin, Rachel; McPherson, John; Miner, Tracie; Nash, William; Nguyen, Christine; Ozersky, Philip; Pepin, Kymberlie; Rock, Susan; Rohlfing, Tracy; Scott, Kelsi; Schultz, Brian; Strong, Cindy; Tin-Wollam, Aye; Yang, Shiaw-Pyng; Waterston, Robert H.; Wilson, Richard K.; Rozen, Steve; Page, David C.

    2003-01-01

    The male-specific region of the Y chromosome, the MSY, differentiates the sexes and comprises 95% of the chromosome's length. Here, we report that the MSY is a mosaic of heterochromatic sequences and three classes of euchromatic sequences: X-transposed, X-degenerate and ampliconic. These classes

  20. Identification and removal of low-complexity sites in allele-specific analysis of ChIP-seq data.

    Science.gov (United States)

    Waszak, Sebastian M; Kilpinen, Helena; Gschwind, Andreas R; Orioli, Andrea; Raghav, Sunil K; Witwicki, Robert M; Migliavacca, Eugenia; Yurovsky, Alisa; Lappalainen, Tuuli; Hernandez, Nouria; Reymond, Alexandre; Dermitzakis, Emmanouil T; Deplancke, Bart

    2014-01-15

    High-throughput sequencing technologies enable the genome-wide analysis of the impact of genetic variation on molecular phenotypes at unprecedented resolution. However, although powerful, these technologies can also introduce unexpected artifacts. We investigated the impact of library amplification bias on the identification of allele-specific (AS) molecular events from high-throughput sequencing data derived from chromatin immunoprecipitation assays (ChIP-seq). Putative AS DNA binding activity for RNA polymerase II was determined using ChIP-seq data derived from lymphoblastoid cell lines of two parent-daughter trios. We found that, at high-sequencing depth, many significant AS binding sites suffered from an amplification bias, as evidenced by a larger number of clonal reads representing one of the two alleles. To alleviate this bias, we devised an amplification bias detection strategy, which filters out sites with low read complexity and sites featuring a significant excess of clonal reads. This method will be useful for AS analyses involving ChIP-seq and other functional sequencing assays. The R package abs filter for library clonality simulations and detection of amplification-biased sites is available from http://updepla1srv1.epfl.ch/waszaks/absfilter

  1. Specific gene expression profiles and chromosomal abnormalities are associated with infant disseminated neuroblastoma

    Directory of Open Access Journals (Sweden)

    Kushner Brian

    2009-02-01

    Full Text Available Abstract Background Neuroblastoma (NB tumours have the highest incidence of spontaneous remission, especially among the stage 4s NB subgroup affecting infants. Clinical distinction of stage 4s from lethal stage 4 can be difficult, but critical for therapeutic decisions. The aim of this study was to investigate chromosomal alterations and differential gene expression amongst infant disseminated NB subgroups. Methods Thirty-five NB tumours from patients diagnosed at Results All stage 4s patients underwent spontaneous remission, only 48% stage 4 patients survived despite combined modality therapy. Stage 4 tumours were 90% near-diploid/tetraploid, 44% MYCN amplified, 77% had 1p LOH (50% 1p36, 23% 11q and/or 14q LOH (27% and 47% had 17q gain. Stage 4s were 90% near-triploid, none MYCN amplified and LOH was restricted to 11q. Initial comparison analyses between stage 4s and 4 P P = 0.0054, 91% with higher expression in stage 4. Less definite expression profiles were observed between stage 4s and 4 P P = 0.005 was maintained. Distinct gene expression profiles but no significant association with specific chromosomal region localization was observed between stage 4s and stage 4 Conclusion Specific chromosomal aberrations are associated with distinct gene expression profiles which characterize spontaneously regressing or aggressive infant NB, providing the biological basis for the distinct clinical behaviour.

  2. Reduced risk of recurrent myocardial infarction in homozygous carriers of the chromosome 9p21 rs1333049 C risk allele in the contemporary percutaneous coronary intervention era: a prospective observational study

    Science.gov (United States)

    Hara, Masahiko; Sakata, Yasuhiko; Nakatani, Daisaku; Suna, Shinichiro; Usami, Masaya; Matsumoto, Sen; Ozaki, Kouichi; Nishino, Masami; Sato, Hiroshi; Kitamura, Tetsuhisa; Nanto, Shinsuke; Hamasaki, Toshimitsu; Tanaka, Toshihiro; Hori, Masatsugu; Komuro, Issei

    2014-01-01

    Objectives Chromosome 9p21 single nucleotide polymorphism (SNP) is a susceptibility variant for acute myocardial infarction (AMI) in the primary prevention setting. However, it is controversial whether this SNP is also associated with recurrent myocardial infarction (ReMI) in the secondary prevention setting. The purpose of this study is to evaluate the impact of chromosome 9p21 SNP on ReMI in patients receiving secondary prevention programmes after AMI. Design A prospective observational study. Setting Osaka Acute Coronary Insufficiency Study (OACIS) in Japan. Participants 2022 patients from the OACIS database. Interventions Genotyping of the 9p21 rs1333049 variant. Primary outcome measures ReMI event after survival discharge for 1 year. Results A total of 43 ReMI occurred during the 1 year follow-up period. Although the rs1333049 C allele had an increased susceptibility to their first AMI in an additive model when compared with 1373 healthy controls (OR 1.20, 95% CI 1.09 to 1.33, p=2.3*10−4), patients with the CC genotype had a lower incidence of ReMI at 1 year after discharge of AMI (log-rank p=0.005). The adjusted HR of the CC genotype as compared with the CG/GG genotypes was 0.20 (0.06 to 0.65, p=0.007). Subgroup analysis demonstrated that the association between the rs1333049 CC genotype and a lower incidence of 1 year ReMI was common to all subgroups. Conclusions Homozygous carriers of the rs1333049 C allele on chromosome 9p21 showed a reduced risk of 1 year ReMI in the contemporary percutaneous coronary intervention era, although the C allele had conferred susceptibility to their first AMI. PMID:25232560

  3. Specific β-turns precede PPIIL structures binding to allele-specific HLA-DRβ1* PBRs in fully-protective malaria vaccine components

    Science.gov (United States)

    Bermudez, Adriana; Alba, Martha P.; Vanegas, Magnolia; Patarroyo, Manuel A.; Patarroyo, Manuel E.

    2018-04-01

    The 3D structural analysis of 62 peptides derived from highly pathogenic Plasmodium falciparum malaria parasite proteins involved in host cell invasion led to finding a striking association between particular β-turn types located in the N-terminal peripheral flanking residue region (preceding the polyproline II left-handed structures fitting into the HLA-DRβ* allele family) and modified immune protection-inducing protein structure induced long-lasting protective immunity. This is the first time association between two different secondary structures associated with a specific immunological function has been described: full, long-lasting protective immunity.

  4. Enhanced specificity of TPMT*2 genotyping using unidirectional wild-type and mutant allele-specific scorpion primers in a single tube.

    Directory of Open Access Journals (Sweden)

    Dong Chen

    Full Text Available Genotyping of thiopurine S-methyltransferase (TPMT is recommended for predicting the adverse drug response of thiopurines. In the current study, a novel version of allele-specific PCR (AS-PCR, termed competitive real-time fluorescent AS-PCR (CRAS-PCR was developed to analyze the TPMT*2 genotype in ethnic Chinese. This technique simultaneously uses wild-type and mutant allele-specific scorpion primers in a single reaction. To determine the optimal conditions for both traditional AS-PCR and CRAS-PCR, we used the Taguchi method, an engineering optimization process that balances the concentrations of all components using an orthogonal array rather than a factorial array. Instead of running up to 264 experiments with the conventional factorial method, the Taguchi method achieved the same optimization using only 16 experiments. The optimized CRAS-PCR system completely avoided non-specific amplification occurring in traditional AS-PCR and could be performed at much more relaxed reaction conditions at 1% sensitivity, similar to traditional AS-PCR. TPMT*2 genotyping of 240 clinical samples was consistent with published data. In conclusion, CRAS-PCR is a novel and robust genotyping method, and the Taguchi method is an effective tool for the optimization of molecular analysis techniques.

  5. Allelic diversity of the Plasmodium falciparum erythrocyte membrane protein 1 entails variant-specific red cell surface epitopes.

    Directory of Open Access Journals (Sweden)

    Inès Vigan-Womas

    Full Text Available The clonally variant Plasmodium falciparum PfEMP1 adhesin is a virulence factor and a prime target of humoral immunity. It is encoded by a repertoire of functionally differentiated var genes, which display architectural diversity and allelic polymorphism. Their serological relationship is key to understanding the evolutionary constraints on this gene family and rational vaccine design. Here, we investigated the Palo Alto/VarO and IT4/R29 and 3D7/PF13_003 parasites lines. VarO and R29 form rosettes with uninfected erythrocytes, a phenotype associated with severe malaria. They express an allelic Cys2/group A NTS-DBL1α(1 PfEMP1 domain implicated in rosetting, whose 3D7 ortholog is encoded by PF13_0003. Using these three recombinant NTS-DBL1α(1 domains, we elicited antibodies in mice that were used to develop monovariant cultures by panning selection. The 3D7/PF13_0003 parasites formed rosettes, revealing a correlation between sequence identity and virulence phenotype. The antibodies cross-reacted with the allelic domains in ELISA but only minimally with the Cys4/group B/C PFL1955w NTS-DBL1α. By contrast, they were variant-specific in surface seroreactivity of the monovariant-infected red cells by FACS analysis and in rosette-disruption assays. Thus, while ELISA can differentiate serogroups, surface reactivity assays define the more restrictive serotypes. Irrespective of cumulated exposure to infection, antibodies acquired by humans living in a malaria-endemic area also displayed a variant-specific surface reactivity. Although seroprevalence exceeded 90% for each rosetting line, the kinetics of acquisition of surface-reactive antibodies differed in the younger age groups. These data indicate that humans acquire an antibody repertoire to non-overlapping serotypes within a serogroup, consistent with an antibody-driven diversification pressure at the population level. In addition, the data provide important information for vaccine design, as

  6. Using RAD-seq to recognize sex-specific markers and sex chromosome systems.

    Science.gov (United States)

    Gamble, Tony

    2016-05-01

    Next-generation sequencing methods have initiated a revolution in molecular ecology and evolution (Tautz et al. ). Among the most impressive of these sequencing innovations is restriction site-associated DNA sequencing or RAD-seq (Baird et al. ; Andrews et al. ). RAD-seq uses the Illumina sequencing platform to sequence fragments of DNA cut by a specific restriction enzyme and can generate tens of thousands of molecular genetic markers for analysis. One of the many uses of RAD-seq data has been to identify sex-specific genetic markers, markers found in one sex but not the other (Baxter et al. ; Gamble & Zarkower ). Sex-specific markers are a powerful tool for biologists. At their most basic, they can be used to identify the sex of an individual via PCR. This is useful in cases where a species lacks obvious sexual dimorphism at some or all life history stages. For example, such tests have been important for studying sex differences in life history (Sheldon ; Mossman & Waser ), the management and breeding of endangered species (Taberlet et al. ; Griffiths & Tiwari ; Robertson et al. ) and sexing embryonic material (Hacker et al. ; Smith et al. ). Furthermore, sex-specific markers allow recognition of the sex chromosome system in cases where standard cytogenetic methods fail (Charlesworth & Mank ; Gamble & Zarkower ). Thus, species with male-specific markers have male heterogamety (XY) while species with female-specific markers have female heterogamety (ZW). In this issue, Fowler & Buonaccorsi () illustrate the ease by which RAD-seq data can generate sex-specific genetic markers in rockfish (Sebastes). Moreover, by examining RAD-seq data from two closely related rockfish species, Sebastes chrysomelas and Sebastes carnatus (Fig. ), Fowler & Buonaccorsi () uncover shared sex-specific markers and a conserved sex chromosome system. © 2016 John Wiley & Sons Ltd.

  7. Rapid identification of capybara (Hydrochaeris hydrochaeris through allele-specific PCR

    Directory of Open Access Journals (Sweden)

    Flávio Henrique-Silva

    2005-07-01

    Full Text Available The capybara is the largest rodent in the world and is widely distributed throughout Central and South America.  It is an animal of economic interest due to the pleasant flavor of its meat and higher protein content in comparison  to beef and pork meat.  The hide, hair and fat also have economic advantages. Thus,  as an animal with such high economic potential, it is the target of hunters, even though  hunting capybara is prohibited by law in Brazil.   Due to their  similarities,  capybara meat  is easily confused with  pork  meat.   This  occurs  upon  the apprehension of the  meat  from hunters, as well as in some restaurants that serve capybara meat that was slaughtered clandestinely. In both cases, when the meat is confiscated, those responsible for the crimes claim it is pork meat,  hindering  the enforcement of the law. A practical  course was ministered  to undergraduate biology students enrolled in the elective course Introduction to Genetic  Engineering  at Federal  University  of Sao Carlos (UFSCar, Sao Paulo  State, Brazil.  The  objective  of the  course was to establish  and  apply  a Polymerase  Chain  Reaction  (PCR assay to identify capybara meat and discriminate it in relation  to other types of meat,  including pork. Primers  were designed based  on 12S rRNA,  transthyretin and  growth  hormone  receptor  genes.  The primers generated  capybara specific fragments  of approximately 220, 290 and 330 bp for transthyretin,12S rRNA  and  growth  hormone  receptor,  respectively.   The  duplexes  developed  in the  present work can be used effectively to discriminate capybara meat  from other  animals,  contributing to combating predatory capybara hunting. The results were extensively discussed and the students have contributed to written a paper  to be submitted to a publication.

  8. Binding of doa kinase to specific loci in polytene chromosomes of Drosophila melanogaster

    Czech Academy of Sciences Publication Activity Database

    Kováčiková, M.; Raška, Ivan; Mateášik, A.; Chase, B. A.; Farkaš, R.

    2006-01-01

    Roč. 40, č. 1 (2006), s. 21-27 ISSN 1210-0668 R&D Projects: GA MŠk(CZ) LC535; GA ČR(CZ) GA304/02/0342 Grant - others:VEGA(SK) 2/3025/23; SAV(SK) APVT-51-027402; NSF(US) IBN-97-24006; US-SK(SK) 13/029/01 Institutional research plan: CEZ:AV0Z50110509 Keywords : specific protein kinases * DOA * polytene chromosomes Subject RIV: EB - Genetics ; Molecular Biology

  9. Using the Textpresso Site-Specific Recombinases Web server to identify Cre expressing mouse strains and floxed alleles.

    Science.gov (United States)

    Condie, Brian G; Urbanski, William M

    2014-01-01

    Effective tools for searching the biomedical literature are essential for identifying reagents or mouse strains as well as for effective experimental design and informed interpretation of experimental results. We have built the Textpresso Site Specific Recombinases (Textpresso SSR) Web server to enable researchers who use mice to perform in-depth searches of a rapidly growing and complex part of the mouse literature. Our Textpresso Web server provides an interface for searching the full text of most of the peer-reviewed publications that report the characterization or use of mouse strains that express Cre or Flp recombinase. The database also contains most of the publications that describe the characterization or analysis of strains carrying conditional alleles or transgenes that can be inactivated or activated by site-specific recombinases such as Cre or Flp. Textpresso SSR complements the existing online databases that catalog Cre and Flp expression patterns by providing a unique online interface for the in-depth text mining of the site specific recombinase literature.

  10. On the origin of sex chromosomes from meiotic drive

    Science.gov (United States)

    Úbeda, Francisco; Patten, Manus M.; Wild, Geoff

    2015-01-01

    Most animals and many plants make use of specialized chromosomes (sex chromosomes) to determine an individual's sex. Best known are the XY and ZW sex-determination systems. Despite having evolved numerous times, sex chromosomes present something of an evolutionary puzzle. At their origin, alleles that dictate development as one sex or the other (primitive sex chromosomes) face a selective penalty, as they will be found more often in the more abundant sex. How is it possible that primitive sex chromosomes overcome this disadvantage? Any theory for the origin of sex chromosomes must identify the benefit that outweighs this cost and enables a sex-determining mutation to establish in the population. Here we show that a new sex-determining allele succeeds when linked to a sex-specific meiotic driver. The new sex-determining allele benefits from confining the driving allele to the sex in which it gains the benefit of drive. Our model requires few special assumptions and is sufficiently general to apply to the evolution of sex chromosomes in outbreeding cosexual or dioecious species. We highlight predictions of the model that can discriminate between this and previous theories of sex-chromosome origins. PMID:25392470

  11. A and MdMYB1 allele-specific markers controlling apple (Malus x domestica Borkh.) skin color and suitability for marker-assisted selection.

    Science.gov (United States)

    Zhang, X J; Wang, L X; Chen, X X; Liu, Y L; Meng, R; Wang, Y J; Zhao, Z Y

    2014-10-31

    Pre-selection for fruit skin color at the seedling stage would be highly advantageous, with marker-assisted selection offering a potential method for apple pre-selection. A and MdMYB1 alleles are allele-specific DNA markers that are potentially associated with apple skin color, and co-segregate with the Rf and Rni loci, respectively. Here, we assessed the potential application of these 2 alleles for marker-assisted breeding across 30 diverse cultivars and 2 apple seedling progenies. The red skin color phenotype was usually associated with the MdMYB1-1 allele and A(1) allele, respectively, while the 2 molecular markers provided approximately 91% predictability in the 'Fuji' x 'Cripps Pink' and 'Fuji' x 'Gala' progenies. The results obtained from the 30 cultivars and 2 progenies were consistent for the 2 molecular markers. Hence, the results supported that Rf and Rni could be located in a gene cluster, or even correspond to alleles of the same gene. Our results are consistent with the hypothesis that red/yellow dimorphism is controlled by a monogenic system, with the presence of the red anthocyanin pigmentation being dominant. In addition, our results supported that the practical utilization of the 2 function markers to efficiently and accurately select red-skinned apple cultivars in apple scion breeding programs.

  12. TumorBoost: Normalization of allele-specific tumor copy numbers from a single pair of tumor-normal genotyping microarrays

    Directory of Open Access Journals (Sweden)

    Neuvial Pierre

    2010-05-01

    Full Text Available Abstract Background High-throughput genotyping microarrays assess both total DNA copy number and allelic composition, which makes them a tool of choice for copy number studies in cancer, including total copy number and loss of heterozygosity (LOH analyses. Even after state of the art preprocessing methods, allelic signal estimates from genotyping arrays still suffer from systematic effects that make them difficult to use effectively for such downstream analyses. Results We propose a method, TumorBoost, for normalizing allelic estimates of one tumor sample based on estimates from a single matched normal. The method applies to any paired tumor-normal estimates from any microarray-based technology, combined with any preprocessing method. We demonstrate that it increases the signal-to-noise ratio of allelic signals, making it significantly easier to detect allelic imbalances. Conclusions TumorBoost increases the power to detect somatic copy-number events (including copy-neutral LOH in the tumor from allelic signals of Affymetrix or Illumina origin. We also conclude that high-precision allelic estimates can be obtained from a single pair of tumor-normal hybridizations, if TumorBoost is combined with single-array preprocessing methods such as (allele-specific CRMA v2 for Affymetrix or BeadStudio's (proprietary XY-normalization method for Illumina. A bounded-memory implementation is available in the open-source and cross-platform R package aroma.cn, which is part of the Aroma Project (http://www.aroma-project.org/.

  13. Appearance and evolution of the specific chromosomal rearrangements associated with malignant transformation of mouse m5S cells

    International Nuclear Information System (INIS)

    Kodama, S.; Okumura, Y.; Komatsu, K.; Sasaki, M.S.

    1991-01-01

    Chromosomal alterations were studied during the acquisition of malignant phenotypes in two karyotypically distinct cells isolated from transformed foci induced by x-irradiation in mouse m5S cells. Because the transformants, despite foci origin, showed low ability to grow in agar, they were cultured in vitro with serial transfer schedules to allow further cell generations and assayed for anchorage independence (AI) at each passage level. The AI frequency increased with the cell doubling numbers. Chromosome analysis showed that a focus was one cell origin, but the transformants showed karyotypic instability during cell proliferation, giving rise to the rearrangements clustered in the distal region of the specific chromosomes. These rearrangements appeared to be directed toward the acquisition of malignant phenotypes. Analysis of the types and sites of rearrangements indicated that a mechanism exists that induces frequent rearrangements of the specific region of a chromosome during the process of transformation into the malignant state

  14. Comparative AFLP reveals paternal sex ratio chromosome specific DNA sequences in the parasitoid wasp Trichogramma kaykai

    NARCIS (Netherlands)

    Vugt, van J.J.F.A.; Hulst, van der R.G.M.; Pruijssers, A.; Verbaarschot, P.G.H.; Stouthamer, R.; Jong, de H.

    2009-01-01

    The parasitoid wasp Trichogramma kaykai with a haplo-diploid sex determination has a B chromosome called the paternal sex ratio (PSR) chromosome that confers paternal genome loss during early embryogenesis, resulting in male offspring. So far, it is not well known whether the PSR chromosome has

  15. Efficient site-specific integration in Plasmodium falciparum chromosomes mediated by mycobacteriophage Bxb1 integrase.

    Science.gov (United States)

    Nkrumah, Louis J; Muhle, Rebecca A; Moura, Pedro A; Ghosh, Pallavi; Hatfull, Graham F; Jacobs, William R; Fidock, David A

    2006-08-01

    Here we report an efficient, site-specific system of genetic integration into Plasmodium falciparum malaria parasite chromosomes. This is mediated by mycobacteriophage Bxb1 integrase, which catalyzes recombination between an incoming attP and a chromosomal attB site. We developed P. falciparum lines with the attB site integrated into the glutaredoxin-like cg6 gene. Transfection of these attB(+) lines with a dual-plasmid system, expressing a transgene on an attP-containing plasmid together with a drug resistance gene and the integrase on a separate plasmid, produced recombinant parasites within 2 to 4 weeks that were genetically uniform for single-copy plasmid integration. Integrase-mediated recombination resulted in proper targeting of parasite proteins to intra-erythrocytic compartments, including the apicoplast, a plastid-like organelle. Recombinant attB x attP parasites were genetically stable in the absence of drug and were phenotypically homogeneous. This system can be exploited for rapid genetic integration and complementation analyses at any stage of the P. falciparum life cycle, and it illustrates the utility of Bxb1-based integrative recombination for genetic studies of intracellular eukaryotic organisms.

  16. Associations between gastric dilatation-volvulus in Great Danes and specific alleles of the canine immune-system genes DLA88, DRB1, and TLR5.

    Science.gov (United States)

    Harkey, Michael A; Villagran, Alexandra M; Venkataraman, Gopalakrishnan M; Leisenring, Wendy M; Hullar, Meredith A J; Torok-Storb, Beverly J

    2017-08-01

    OBJECTIVE To determine whether specific alleles of candidate genes of the major histocompatibility complex (MHC) and innate immune system were associated with gastric dilatation-volvulus (GDV) in Great Danes. ANIMALS 42 healthy Great Danes (control group) and 39 Great Danes with ≥ 1 GDV episode. PROCEDURES Variable regions of the 2 most polymorphic MHC genes (DLA88 and DRB1) were amplified and sequenced from the dogs in each group. Similarly, regions of 3 genes associated with the innate immune system (TLR5, NOD2, and ATG16L1), which have been linked to inflammatory bowel disease, were amplified and sequenced. Alleles were evaluated for associations with GDV, controlling for age and dog family. RESULTS Specific alleles of genes DLA88, DRB1, and TLR5 were significantly associated with GDV. One allele of each gene had an OR > 2 in the unadjusted univariate analyses and retained a hazard ratio > 2 after controlling for temperament, age, and familial association in the multivariate analysis. CONCLUSIONS AND CLINICAL RELEVANCE The 3 GDV-associated alleles identified in this study may serve as diagnostic markers for identification of Great Danes at risk for GDV. Additional research is needed to determine whether other dog breeds have the same genetic associations. These findings also provided a new target for research into the etiology of, and potential treatments for, GDV in dogs.

  17. The Pleiotropic Phenotype of Apc Mutations in the Mouse: Allele Specificity and Effects of the Genetic Background

    Science.gov (United States)

    Halberg, Richard B.; Chen, Xiaodi; Amos-Landgraf, James M.; White, Alanna; Rasmussen, Kristin; Clipson, Linda; Pasch, Cheri; Sullivan, Ruth; Pitot, Henry C.; Dove, William F.

    2008-01-01

    Familial adenomatous polyposis (FAP) is a human cancer syndrome characterized by the development of hundreds to thousands of colonic polyps and extracolonic lesions including desmoid fibromas, osteomas, epidermoid cysts, and congenital hypertrophy of the pigmented retinal epithelium. Afflicted individuals are heterozygous for mutations in the APC gene. Detailed investigations of mice heterozygous for mutations in the ortholog Apc have shown that other genetic factors strongly influence the phenotype. Here we report qualitative and quantitative modifications of the phenotype of Apc mutants as a function of three genetic variables: Apc allele, p53 allele, and genetic background. We have found major differences between the Apc alleles Min and 1638N in multiplicity and regionality of intestinal tumors, as well as in incidence of extracolonic lesions. By contrast, Min mice homozygous for either of two different knockout alleles of p53 show similar phenotypic effects. These studies illustrate the classic principle that functional genetics is enriched by assessing penetrance and expressivity with allelic series. The mouse permits study of an allelic gene series on multiple genetic backgrounds, thereby leading to a better understanding of gene action in a range of biological processes. PMID:18723878

  18. Chromosome region-specific libraries for human genome analysis. Final progress report, 1 March 1991--28 February 1994

    Energy Technology Data Exchange (ETDEWEB)

    Kao, F.T.

    1994-04-01

    The objectives of this grant proposal include (1) development of a chromosome microdissection and PCR-mediated microcloning technology, (2) application of this microtechnology to the construction of region-specific libraries for human genome analysis. During this grant period, the authors have successfully developed this microtechnology and have applied it to the construction of microdissection libraries for the following chromosome regions: a whole chromosome 21 (21E), 2 region-specific libraries for the long arm of chromosome 2, 2q35-q37 (2Q1) and 2q33-q35 (2Q2), and 4 region-specific libraries for the entire short arm of chromosome 2, 2p23-p25 (2P1), 2p21-p23 (2P2), 2p14-p16 (wP3) and 2p11-p13 (2P4). In addition, 20--40 unique sequence microclones have been isolated and characterized for genomic studies. These region-specific libraries and the single-copy microclones from the library have been used as valuable resources for (1) isolating microsatellite probes in linkage analysis to further refine the disease locus; (2) isolating corresponding clones with large inserts, e.g. YAC, BAC, P1, cosmid and phage, to facilitate construction of contigs for high resolution physical mapping; and (3) isolating region-specific cDNA clones for use as candidate genes. These libraries are being deposited in the American Type Culture Collection (ATCC) for general distribution.

  19. Cyc17, a meiosis-specific cyclin, is essential for anaphase initiation and chromosome segregation in Tetrahymena thermophila.

    Science.gov (United States)

    Yan, Guan-Xiong; Dang, Huai; Tian, Miao; Zhang, Jing; Shodhan, Anura; Ning, Ying-Zhi; Xiong, Jie; Miao, Wei

    2016-07-17

    Although the role of cyclins in controlling nuclear division is well established, their function in ciliate meiosis remains unknown. In ciliates, the cyclin family has undergone massive expansion which suggests that diverse cell cycle systems exist, and this warrants further investigation. A screen for cyclins in the model ciliate Tetrahymena thermophila showed that there are 34 cyclins in this organism. Only 1 cyclin, Cyc17, contains the complete cyclin core and is specifically expressed during meiosis. Deletion of CYC17 led to meiotic arrest at the diakinesis-like metaphase I stage. Expression of genes involved in DNA metabolism and chromosome organization (chromatin remodeling and basic chromosomal structure) was repressed in cyc17 knockout matings. Further investigation suggested that Cyc17 is involved in regulating spindle pole attachment, and is thus essential for chromosome segregation at meiosis. These findings suggest a simple model in which chromosome segregation is influenced by Cyc17.

  20. A common polymorphism in the promoter region of the TNFSF4 gene is associated with lower allele-specific expression and risk of myocardial infarction.

    Directory of Open Access Journals (Sweden)

    Massimiliano Ria

    Full Text Available BACKGROUND: The TNFSF4/TNFRSF4 system, along with several other receptor-ligand pairs, is involved in the recruitment and activation of T-cells and is therefore tentatively implicated in atherosclerosis and acute coronary syndromes. We have previously shown that genetic variants in TNFSF4 are associated with myocardial infarction (MI in women. This prompted functional studies of TNFSF4 expression. METHODS AND RESULTS: Based on a screening of the TNFSF4 genomic region, a promoter polymorphism (rs45454293 and a haplotype were identified, conceivably involved in gene regulation. The rs45454293T-allele, in agreement with the linked rs3850641G-allele, proved to be associated with increased risk of MI in women. Haplotype-specific chromatin immunoprecipitation of activated polymerase II, as a measure of transcriptional activity in vivo, suggested that the haplotype including the rs45454293 and rs3850641 polymorphisms is functionally important, the rs45454293T- and rs3850641G-alleles being associated with lower transcriptional activity in cells heterozygous for both polymorphisms. The functional role of rs45454293 on transcriptional levels of TNFSF4 was clarified by luciferase reporter assays, where the rs45454293T-allele decreased gene expression when compared with the rs45454293C-allele, while the rs3850641 SNP did not have any effect on TNFSF4 promoter activity. Electromobility shift assay showed that the rs45454293 polymorphism, but not rs3850641, affects the binding of nuclear factors, thus suggesting that the lower transcriptional activity is attributed to binding of one or more transcriptional repressor(s to the T-allele. CONCLUSIONS: Our data indicate that the TNFSF4 rs45454293T-allele is associated with lower TNFSF4 expression and increased risk of MI.

  1. Development of Allele-Specific Primer PCR for a Swine TLR2 SNP and Comparison of the Frequency among Several Pig Breeds of Japan and the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Muneta, Y.; Minagawa, Y.; Kusumoto, M.; Shinkai, H.; Uenishi, H.; Šplíchal, Igor

    2012-01-01

    Roč. 74, č. 5 (2012), s. 553-559 ISSN 0916-7250 R&D Projects: GA ČR GA524/09/0365 Institutional support: RVO:61388971 Keywords : allele-specific PCR * Mycoplasma hyopneumoniae * single nucleotide polymorphism Subject RIV: EC - Immunology Impact factor: 0.876, year: 2012

  2. Allele-specific gene expression patterns in primary leukemic cells reveal regulation of gene expression by CpG site methylation

    DEFF Research Database (Denmark)

    Milani, Lili; Lundmark, Anders; Nordlund, Jessica

    2008-01-01

    To identify genes that are regulated by cis-acting functional elements in acute lymphoblastic leukemia (ALL) we determined the allele-specific expression (ASE) levels of 2, 529 genes by genotyping a genome-wide panel of single nucleotide polymorphisms in RNA and DNA from bone marrow and blood...

  3. Inter- and intra-individual variation in allele-specific DNA methylation and gene expression in children conceived using assisted reproductive technology.

    Directory of Open Access Journals (Sweden)

    Nahid Turan

    2010-07-01

    Full Text Available Epidemiological studies have reported a higher incidence of rare disorders involving imprinted genes among children conceived using assisted reproductive technology (ART, suggesting that ART procedures may be disruptive to imprinted gene methylation patterns. We examined intra- and inter-individual variation in DNA methylation at the differentially methylated regions (DMRs of the IGF2/H19 and IGF2R loci in a population of children conceived in vitro or in vivo. We found substantial variation in allele-specific methylation at both loci in both groups. Aberrant methylation of the maternal IGF2/H19 DMR was more common in the in vitro group, and the overall variance was also significantly greater in the in vitro group. We estimated the number of trophoblast stem cells in each group based on approximation of the variance of the binomial distribution of IGF2/H19 methylation ratios, as well as the distribution of X chromosome inactivation scores in placenta. Both of these independent measures indicated that placentas of the in vitro group were derived from fewer stem cells than the in vivo conceived group. Both IGF2 and H19 mRNAs were significantly lower in placenta from the in vitro group. Although average birth weight was lower in the in vitro group, we found no correlation between birth weight and IGF2 or IGF2R transcript levels or the ratio of IGF2/IGF2R transcript levels. Our results show that in vitro conception is associated with aberrant methylation patterns at the IGF2/H19 locus. However, very little of the inter- or intra-individual variation in H19 or IGF2 mRNA levels can be explained by differences in maternal DMR DNA methylation, in contrast to the expectations of current transcriptional imprinting models. Extraembryonic tissues of embryos cultured in vitro appear to be derived from fewer trophoblast stem cells. It is possible that this developmental difference has an effect on placental and fetal growth.

  4. Bamgineer: Introduction of simulated allele-specific copy number variants into exome and targeted sequence data sets.

    Science.gov (United States)

    Samadian, Soroush; Bruce, Jeff P; Pugh, Trevor J

    2018-03-01

    Somatic copy number variations (CNVs) play a crucial role in development of many human cancers. The broad availability of next-generation sequencing data has enabled the development of algorithms to computationally infer CNV profiles from a variety of data types including exome and targeted sequence data; currently the most prevalent types of cancer genomics data. However, systemic evaluation and comparison of these tools remains challenging due to a lack of ground truth reference sets. To address this need, we have developed Bamgineer, a tool written in Python to introduce user-defined haplotype-phased allele-specific copy number events into an existing Binary Alignment Mapping (BAM) file, with a focus on targeted and exome sequencing experiments. As input, this tool requires a read alignment file (BAM format), lists of non-overlapping genome coordinates for introduction of gains and losses (bed file), and an optional file defining known haplotypes (vcf format). To improve runtime performance, Bamgineer introduces the desired CNVs in parallel using queuing and parallel processing on a local machine or on a high-performance computing cluster. As proof-of-principle, we applied Bamgineer to a single high-coverage (mean: 220X) exome sequence file from a blood sample to simulate copy number profiles of 3 exemplar tumors from each of 10 tumor types at 5 tumor cellularity levels (20-100%, 150 BAM files in total). To demonstrate feasibility beyond exome data, we introduced read alignments to a targeted 5-gene cell-free DNA sequencing library to simulate EGFR amplifications at frequencies consistent with circulating tumor DNA (10, 1, 0.1 and 0.01%) while retaining the multimodal insert size distribution of the original data. We expect Bamgineer to be of use for development and systematic benchmarking of CNV calling algorithms by users using locally-generated data for a variety of applications. The source code is freely available at http://github.com/pughlab/bamgineer.

  5. Bamgineer: Introduction of simulated allele-specific copy number variants into exome and targeted sequence data sets.

    Directory of Open Access Journals (Sweden)

    Soroush Samadian

    2018-03-01

    Full Text Available Somatic copy number variations (CNVs play a crucial role in development of many human cancers. The broad availability of next-generation sequencing data has enabled the development of algorithms to computationally infer CNV profiles from a variety of data types including exome and targeted sequence data; currently the most prevalent types of cancer genomics data. However, systemic evaluation and comparison of these tools remains challenging due to a lack of ground truth reference sets. To address this need, we have developed Bamgineer, a tool written in Python to introduce user-defined haplotype-phased allele-specific copy number events into an existing Binary Alignment Mapping (BAM file, with a focus on targeted and exome sequencing experiments. As input, this tool requires a read alignment file (BAM format, lists of non-overlapping genome coordinates for introduction of gains and losses (bed file, and an optional file defining known haplotypes (vcf format. To improve runtime performance, Bamgineer introduces the desired CNVs in parallel using queuing and parallel processing on a local machine or on a high-performance computing cluster. As proof-of-principle, we applied Bamgineer to a single high-coverage (mean: 220X exome sequence file from a blood sample to simulate copy number profiles of 3 exemplar tumors from each of 10 tumor types at 5 tumor cellularity levels (20-100%, 150 BAM files in total. To demonstrate feasibility beyond exome data, we introduced read alignments to a targeted 5-gene cell-free DNA sequencing library to simulate EGFR amplifications at frequencies consistent with circulating tumor DNA (10, 1, 0.1 and 0.01% while retaining the multimodal insert size distribution of the original data. We expect Bamgineer to be of use for development and systematic benchmarking of CNV calling algorithms by users using locally-generated data for a variety of applications. The source code is freely available at http://github.com/pughlab/bamgineer.

  6. Hybrid sterility and evolution in Hawaiian Drosophila: differential gene and allele-specific expression analysis of backcross males.

    Science.gov (United States)

    Brill, E; Kang, L; Michalak, K; Michalak, P; Price, D K

    2016-08-01

    The Hawaiian Drosophila are an iconic example of sequential colonization, adaptive radiation and speciation on islands. Genetic and phenotypic analysis of closely related species pairs that exhibit incomplete reproductive isolation can provide insights into the mechanisms of speciation. Drosophila silvestris from Hawai'i Island and Drosophila planitibia from Maui are two closely related allopatric Hawaiian picture-winged Drosophila that produce sterile F1 males but fertile F1 females, a pattern consistent with Haldane's rule. Backcrossing F1 hybrid females between these two species to parental species gives rise to recombinant males with three distinct sperm phenotypes despite a similar genomic background: motile sperm, no sperm (sterile), and immotile sperm. We found that these three reproductive morphologies of backcross hybrid males produce divergent gene expression profiles in testes, as measured with RNA sequencing. There were a total of 71 genes significantly differentially expressed between backcross males with no sperm compared with those backcross males with motile sperm and immotile sperm, but no significant differential gene expression between backcross males with motile sperm and backcross males with immotile sperm. All of these genes were underexpressed in males with no sperm, including a number of genes with previously known activities in adult testis. An allele-specific expression analysis showed overwhelmingly more cis-divergent than trans-divergent genes, with no significant difference in the ratio of cis- and trans-divergent genes among the sperm phenotypes. Overall, the results indicate that the regulation of gene expression involved in sperm production likely diverged relatively rapidly between these two closely related species.

  7. WASP: a Web-based Allele-Specific PCR assay designing tool for detecting SNPs and mutations

    Directory of Open Access Journals (Sweden)

    Assawamakin Anunchai

    2007-08-01

    Full Text Available Abstract Background Allele-specific (AS Polymerase Chain Reaction is a convenient and inexpensive method for genotyping Single Nucleotide Polymorphisms (SNPs and mutations. It is applied in many recent studies including population genetics, molecular genetics and pharmacogenomics. Using known AS primer design tools to create primers leads to cumbersome process to inexperience users since information about SNP/mutation must be acquired from public databases prior to the design. Furthermore, most of these tools do not offer the mismatch enhancement to designed primers. The available web applications do not provide user-friendly graphical input interface and intuitive visualization of their primer results. Results This work presents a web-based AS primer design application called WASP. This tool can efficiently design AS primers for human SNPs as well as mutations. To assist scientists with collecting necessary information about target polymorphisms, this tool provides a local SNP database containing over 10 million SNPs of various populations from public domain databases, namely NCBI dbSNP, HapMap and JSNP respectively. This database is tightly integrated with the tool so that users can perform the design for existing SNPs without going off the site. To guarantee specificity of AS primers, the proposed system incorporates a primer specificity enhancement technique widely used in experiment protocol. In particular, WASP makes use of different destabilizing effects by introducing one deliberate 'mismatch' at the penultimate (second to last of the 3'-end base of AS primers to improve the resulting AS primers. Furthermore, WASP offers graphical user interface through scalable vector graphic (SVG draw that allow users to select SNPs and graphically visualize designed primers and their conditions. Conclusion WASP offers a tool for designing AS primers for both SNPs and mutations. By integrating the database for known SNPs (using gene ID or rs number

  8. siRNA-mediated Allele-specific Silencing of a COL6A3 Mutation in a Cellular Model of Dominant Ullrich Muscular Dystrophy

    Directory of Open Access Journals (Sweden)

    Véronique Bolduc

    2014-01-01

    Full Text Available Congenital muscular dystrophy type Ullrich (UCMD is a severe disorder of early childhood onset for which currently there is no effective treatment. UCMD commonly is caused by dominant-negative mutations in the genes coding for collagen type VI, a major microfibrillar component of the extracellular matrix surrounding the muscle fibers. To explore RNA interference (RNAi as a potential therapy for UCMD, we designed a series of small interfering RNA (siRNA oligos that specifically target the most common mutations resulting in skipping of exon 16 in the COL6A3 gene and tested them in UCMD-derived dermal fibroblasts. Transcript analysis by semiquantitative and quantitative reverse transcriptase PCR showed that two of these siRNAs were the most allele-specific, i.e., they efficiently knocked down the expression from the mutant allele, without affecting the normal allele. In HEK293T cells, these siRNAs selectively suppressed protein expression from a reporter construct carrying the mutation, with no or minimal suppression of the wild-type (WT construct, suggesting that collagen VI protein levels are as also reduced in an allele-specific manner. Furthermore, we found that treating UCMD fibroblasts with these siRNAs considerably improved the quantity and quality of the collagen VI matrix, as assessed by confocal microscopy. Our current study establishes RNAi as a promising molecular approach for treating dominant COL6-related dystrophies.

  9. High-resolution whole-genome sequencing reveals that specific chromatin domains from most human chromosomes associate with nucleoli.

    Science.gov (United States)

    van Koningsbruggen, Silvana; Gierlinski, Marek; Schofield, Pietá; Martin, David; Barton, Geoffey J; Ariyurek, Yavuz; den Dunnen, Johan T; Lamond, Angus I

    2010-11-01

    The nuclear space is mostly occupied by chromosome territories and nuclear bodies. Although this organization of chromosomes affects gene function, relatively little is known about the role of nuclear bodies in the organization of chromosomal regions. The nucleolus is the best-studied subnuclear structure and forms around the rRNA repeat gene clusters on the acrocentric chromosomes. In addition to rDNA, other chromatin sequences also surround the nucleolar surface and may even loop into the nucleolus. These additional nucleolar-associated domains (NADs) have not been well characterized. We present here a whole-genome, high-resolution analysis of chromatin endogenously associated with nucleoli. We have used a combination of three complementary approaches, namely fluorescence comparative genome hybridization, high-throughput deep DNA sequencing and photoactivation combined with time-lapse fluorescence microscopy. The data show that specific sequences from most human chromosomes, in addition to the rDNA repeat units, associate with nucleoli in a reproducible and heritable manner. NADs have in common a high density of AT-rich sequence elements, low gene density and a statistically significant enrichment in transcriptionally repressed genes. Unexpectedly, both the direct DNA sequencing and fluorescence photoactivation data show that certain chromatin loci can specifically associate with either the nucleolus, or the nuclear envelope.

  10. Chromosome specific DNA hybridization in suspension for flow cytometric detection of chimerism in bone marrow transplantation and leukemia

    NARCIS (Netherlands)

    G.J.A. Arkesteijn (Ger); C.A.J. Erpelinck (Claudia); A.C.M. Martens (Anton); A. Hagenbeek (Anton)

    1995-01-01

    textabstractFlow cytometry was used to measure the fluorescence intensity of nuclei that were subjected to fluorescent in situ hybridization in suspension with chromosome specific DNA probes. Paraformaldehyde-fixed nuclei were protein digested with trypsin and hybridized simultaneously with a

  11. Development of a Set of Chromosome-Specific Cytogenetic DNA Markers in Sunflower Using BAC-FISH

    Science.gov (United States)

    In diploid sunflower (2n=34), conventional karyotypes and various genetic linkage maps have been established. However, the relationship between genetic linkage groups and individual chromosomes of sunflower remains unknown. Recently, a set of linkage group-specific BAC and BIBAC clones were identifi...

  12. Long-range chromosome organization in E. coli: a site-specific system isolates the Ter macrodomain.

    Science.gov (United States)

    Thiel, Axel; Valens, Michèle; Vallet-Gely, Isabelle; Espéli, Olivier; Boccard, Frédéric

    2012-01-01

    The organization of the Escherichia coli chromosome into a ring composed of four macrodomains and two less-structured regions influences the segregation of sister chromatids and the mobility of chromosomal DNA. The structuring of the terminus region (Ter) into a macrodomain relies on the interaction of the protein MatP with a 13-bp target called matS repeated 23 times in the 800-kb-long domain. Here, by using a new method that allows the transposition of any chromosomal segment at a defined position on the genetic map, we reveal a site-specific system that restricts to the Ter region a constraining process that reduces DNA mobility and delays loci segregation. Remarkably, the constraining process is regulated during the cell cycle and occurs only when the Ter MD is associated with the division machinery at mid-cell. The change of DNA properties does not rely on the presence of a trans-acting mechanism but rather involves a cis-effect acting at a long distance from the Ter region. Two specific 12-bp sequences located in the flanking Left and Right macrodomains and a newly identified protein designated YfbV conserved with MatP through evolution are required to impede the spreading of the constraining process to the rest of the chromosome. Our results unravel a site-specific system required to restrict to the Ter region the consequences of anchoring the Ter MD to the division machinery.

  13. Systematic evaluation of the impact of ChIP-seq read designs on genome coverage, peak identification, and allele-specific binding detection.

    Science.gov (United States)

    Zhang, Qi; Zeng, Xin; Younkin, Sam; Kawli, Trupti; Snyder, Michael P; Keleş, Sündüz

    2016-02-24

    Chromatin immunoprecipitation followed by sequencing (ChIP-seq) experiments revolutionized genome-wide profiling of transcription factors and histone modifications. Although maturing sequencing technologies allow these experiments to be carried out with short (36-50 bps), long (75-100 bps), single-end, or paired-end reads, the impact of these read parameters on the downstream data analysis are not well understood. In this paper, we evaluate the effects of different read parameters on genome sequence alignment, coverage of different classes of genomic features, peak identification, and allele-specific binding detection. We generated 101 bps paired-end ChIP-seq data for many transcription factors from human GM12878 and MCF7 cell lines. Systematic evaluations using in silico variations of these data as well as fully simulated data, revealed complex interplay between the sequencing parameters and analysis tools, and indicated clear advantages of paired-end designs in several aspects such as alignment accuracy, peak resolution, and most notably, allele-specific binding detection. Our work elucidates the effect of design on the downstream analysis and provides insights to investigators in deciding sequencing parameters in ChIP-seq experiments. We present the first systematic evaluation of the impact of ChIP-seq designs on allele-specific binding detection and highlights the power of pair-end designs in such studies.

  14. Characterization of the peptide binding specificity of the HLA class I alleles B*38:01 and B*39:06.

    Science.gov (United States)

    Sidney, John; Schloss, Jennifer; Moore, Carrie; Lindvall, Mikaela; Wriston, Amanda; Hunt, Donald F; Shabanowitz, Jeffrey; DiLorenzo, Teresa P; Sette, Alessandro

    2016-03-01

    B*38:01 and B*39:06 are present with phenotypic frequencies 39:06 is the B allele most associated with type 1 diabetes susceptibility and 38:01 is most protective. A previous study derived putative main anchor motifs for both alleles based on peptide elution data. The present study has utilized panels of single amino acid substitution peptide libraries to derive detailed quantitative motifs accounting for both primary and secondary influences on peptide binding. From these analyses, both alleles were confirmed to utilize the canonical position 2/C-terminus main anchor spacing. B*38:01 preferentially bound peptides with the positively charged or polar residues H, R, and Q in position 2 and the large hydrophobic residues I, F, L, W, and M at the C-terminus. B*39:06 had a similar preference for R in position 2, but also well-tolerated M, Q, and K. A more dramatic contrast between the two alleles was noted at the C-terminus, where the specificity of B*39:06 was clearly for small residues, with A as most preferred, followed by G, V, S, T, and I. Detailed position-by-position and residue-by-residue coefficient values were generated from the panels to provide detailed quantitative B*38:01 and B*39:06 motifs. It is hoped that these detailed motifs will facilitate the identification of T cell epitopes recognized in the context of two class I alleles associated with dramatically different dispositions towards type 1 diabetes, offering potential avenues for the investigation of the role of CD8 T cells in this disease.

  15. Microarray Analysis of Copy Number Variants on the Human Y Chromosome Reveals Novel and Frequent Duplications Overrepresented in Specific Haplogroups.

    Directory of Open Access Journals (Sweden)

    Martin M Johansson

    Full Text Available The human Y chromosome is almost always excluded from genome-wide investigations of copy number variants (CNVs due to its highly repetitive structure. This chromosome should not be forgotten, not only for its well-known relevance in male fertility, but also for its involvement in clinical phenotypes such as cancers, heart failure and sex specific effects on brain and behaviour.We analysed Y chromosome data from Affymetrix 6.0 SNP arrays and found that the signal intensities for most of 8179 SNP/CN probes in the male specific region (MSY discriminated between a male, background signals in a female and an isodicentric male containing a large deletion of the q-arm and a duplication of the p-arm of the Y chromosome. Therefore, this SNP/CN platform is suitable for identification of gain and loss of Y chromosome sequences. In a set of 1718 males, we found 25 different CNV patterns, many of which are novel. We confirmed some of these variants by PCR or qPCR. The total frequency of individuals with CNVs was 14.7%, including 9.5% with duplications, 4.5% with deletions and 0.7% exhibiting both. Hence, a novel observation is that the frequency of duplications was more than twice the frequency of deletions. Another striking result was that 10 of the 25 detected variants were significantly overrepresented in one or more haplogroups, demonstrating the importance to control for haplogroups in genome-wide investigations to avoid stratification. NO-M214(xM175 individuals presented the highest percentage (95% of CNVs. If they were not counted, 12.4% of the rest included CNVs, and the difference between duplications (8.9% and deletions (2.8% was even larger.Our results demonstrate that currently available genome-wide SNP platforms can be used to identify duplications and deletions in the human Y chromosome. Future association studies of the full spectrum of Y chromosome variants will demonstrate the potential involvement of gain or loss of Y chromosome sequence in

  16. Use of allele-specific FAIRE to determine functional regulatory polymorphism using large-scale genotyping arrays

    DEFF Research Database (Denmark)

    Smith, Frank Andrew; Howard, Philip; Shah, Sonia

    2012-01-01

    Following the widespread use of genome-wide association studies (GWAS), focus is turning towards identification of causal variants rather than simply genetic markers of diseases and traits. As a step towards a high-throughput method to identify genome-wide, non-coding, functional regulatory...... discrimination. Examination of this SNP in two prospective Caucasian cohorts comprising 15,000 individuals confirmed the association with HDL-C levels (combined beta = 0.016; p = 0.0006), and analysis of gene expression identified an allelic association with LXR-α expression in heart tissue. Using increasingly...

  17. Tumor-specific chromosome mis-segregation controls cancer plasticity by maintaining tumor heterogeneity.

    Directory of Open Access Journals (Sweden)

    Yuanjie Hu

    Full Text Available Aneuploidy with chromosome instability is a cancer hallmark. We studied chromosome 7 (Chr7 copy number variation (CNV in gliomas and in primary cultures derived from them. We found tumor heterogeneity with cells having Chr7-CNV commonly occurs in gliomas, with a higher percentage of cells in high-grade gliomas carrying more than 2 copies of Chr7, as compared to low-grade gliomas. Interestingly, all Chr7-aneuploid cell types in the parental culture of established glioma cell lines reappeared in single-cell-derived subcultures. We then characterized the biology of three syngeneic glioma cultures dominated by different Chr7-aneuploid cell types. We found phenotypic divergence for cells following Chr7 mis-segregation, which benefited overall tumor growth in vitro and in vivo. Mathematical modeling suggested the involvement of chromosome instability and interactions among cell subpopulations in restoring the optimal equilibrium of tumor cell types. Both our experimental data and mathematical modeling demonstrated that the complexity of tumor heterogeneity could be enhanced by the existence of chromosomes with structural abnormality, in addition to their mis-segregations. Overall, our findings show, for the first time, the involvement of chromosome instability in maintaining tumor heterogeneity, which underlies the enhanced growth, persistence and treatment resistance of cancers.

  18. Persistence of Breakage in Specific Chromosome Bands 6 Years after Acute Exposure to Oil.

    Directory of Open Access Journals (Sweden)

    Alexandra Francés

    Full Text Available The identification of breakpoints involved in chromosomal damage could help to detect genes involved in genetic disorders, most notably cancer. Until now, only one published study, carried out by our group, has identified chromosome bands affected by exposure to oil from an oil spill. In that study, which was performed two years after the initial oil exposure in individuals who had participated in clean-up tasks following the wreck of the Prestige, three chromosomal bands (2q21, 3q27, 5q31 were found to be especially prone to breakage. A recent follow-up study, performed on the same individuals, revealed that the genotoxic damage had persisted six years after oil exposure.To determine whether there exist chromosome bands which are especially prone to breakages and to know if there is some correlation with those detected in the previous study. In addition, to investigate if the DNA repair problems detected previously persist in the present study.Follow-up study performed six years after the Prestige oil spill.Fishermen cooperatives in coastal villages.Fishermen highly exposed to oil spill who participated in previous genotoxic study six years after the oil.Chromosome damage in peripheral lymphocytes. For accurate identification of the breakpoints involved in chromosome damage of circulating lymphocytes, a sequential stain/G-banding technique was employed. To determine the most break-prone chromosome bands, two statistical methods, the Fragile Site Multinomial and the chi-square tests (where the bands were corrected by their length were used. To compare the chromosome lesions, structural chromosome alterations and gaps/breaks between two groups of individuals we used the GEE test which takes into account a possible within-individual correlation. Dysfunctions in DNA repair mechanisms, expressed as chromosome damage, were assessed in cultures with aphidicolin by the GEE test.Cytogenetic analyses were performed in 47 exposed individuals. A total of

  19. Integration of hepatitis B virus DNA in chromosome-specific satellite sequences

    International Nuclear Information System (INIS)

    Shaul, Y.; Garcia, P.D.; Schonberg, S.; Rutter, W.J.

    1986-01-01

    The authors previously reported the cloning and detailed analysis of the integrated hepatitis B virus sequences in a human hepatoma cell line. They report here the integration of at least one of hepatitis B virus at human satellite DNA sequences. The majority of the cellular sequences identified by this satellite were organized as a multimeric composition of a 0.6-kilobase EcoRI fragment. This clone hybridized in situ almost exclusively to the centromeric heterochromatin of chromosomes 1 and 16 and to a lower extent to chromosome 2 and to the heterochromatic region of the Y chromosome. The immediate flanking host sequence appeared as a hierarchy of repeating units which were almost identical to a previously reported human satellite III DNA sequence

  20. Myeloid- and lymphoid-specific breakpoint cluster regions in chromosome band 13q14 in acute leukemia.

    Science.gov (United States)

    Coignet, L J; Lima, C S; Min, T; Streubel, B; Swansbury, J; Telford, N; Swanton, S; Bowen, A; Nagai, M; Catovsky, D; Fonatsch, C; Dyer, M J

    1999-07-01

    Abnormalities of chromosome band 13q14 occur in hematologic malignancies of all lineages and at all stages of differentiation. Unlike other chromosomal translocations, which are usually specific for a given lineage, the chromosomal translocation t(12;13)(p12;q14) has been observed in both B-cell and T-cell precursor acute lymphoblastic leukemia (BCP-, TCP-ALL), in differentiated and undifferentiated acute myeloblastic leukemia (AML), and in chronic myeloid leukemia (CML) at progression to blast crisis. The nature of these translocations and their pathologic consequences remain unknown. To begin to define the gene(s) involved on chromosome 13, we have performed fluorescence in situ hybridization (FISH) using a panel of YACs from the region, on a series of 10 cases of acute leukemia with t(12;13)(p12;q14) and 1 case each with "variant" translocations including t(12;13)(q21;q14), t(10;13)(q24;q14) and t(9;13)(p21;q14). In 8/13 cases/cell lines, the 13q14 break fell within a single 1.4 Mb CEPH MegaYAC. This YAC fell immediately telomeric of the forkhead (FKHR) gene, which is disrupted in the t(2;13)(q35;q14) seen in pediatric alveolar rhabdomyosarcoma. Seven of the 8 cases with breaks in this YAC were AML. In 4/13 cases, the 13q14 break fell within a 1.7-Mb YAC located about 3 Mb telomeric of the retinoblastoma (RB1) gene: all 4 cases were ALL. One case of myelodysplastic syndrome exhibited a break within 13q12, adjacent to the BRCA2 gene. These data indicate the presence of myeloid- and lymphoid-specific breakpoint cluster regions within chromosome band 13q14 in acute leukemia.

  1. Postzygotic isolation involves strong mitochondrial and sex-specific effects in Tigriopus californicus, a species lacking heteromorphic sex chromosomes.

    Science.gov (United States)

    Foley, B R; Rose, C G; Rundle, D E; Leong, W; Edmands, S

    2013-11-01

    Detailed studies of the genetics of speciation have focused on a few model systems, particularly Drosophila. The copepod Tigriopus californicus offers an alternative that differs from standard animal models in that it lacks heteromorphic chromosomes (instead, sex determination is polygenic) and has reduced opportunities for sexual conflict, because females mate only once. Quantitative trait loci (QTL) mapping was conducted on reciprocal F2 hybrids between two strongly differentiated populations, using a saturated linkage map spanning all 12 autosomes and the mitochondrion. By comparing sexes, a possible sex ratio distorter was found but no sex chromosomes. Although studies of standard models often find an excess of hybrid male sterility factors, we found no QTL for sterility and multiple QTL for hybrid viability (indicated by non-Mendelian adult ratios) and other characters. Viability problems were found to be stronger in males, but the usual explanations for weaker hybrid males (sex chromosomes, sensitivity of spermatogenesis, sexual selection) cannot fully account for these male viability problems. Instead, higher metabolic rates may amplify deleterious effects in males. Although many studies of standard speciation models find the strongest genetic incompatibilities to be nuclear-nuclear (specifically X chromosome-autosome), we found the strongest deleterious interaction in this system was mito-nuclear. Consistent with the snowball theory of incompatibility accumulation, we found that trigenic interactions in this highly divergent cross were substantially more frequent (>6×) than digenic interactions. This alternative system thus allows important comparisons to studies of the genetics of reproductive isolation in more standard model systems.

  2. Statistics for X-chromosome associations.

    Science.gov (United States)

    Özbek, Umut; Lin, Hui-Min; Lin, Yan; Weeks, Daniel E; Chen, Wei; Shaffer, John R; Purcell, Shaun M; Feingold, Eleanor

    2018-06-13

    In a genome-wide association study (GWAS), association between genotype and phenotype at autosomal loci is generally tested by regression models. However, X-chromosome data are often excluded from published analyses of autosomes because of the difference between males and females in number of X chromosomes. Failure to analyze X-chromosome data at all is obviously less than ideal, and can lead to missed discoveries. Even when X-chromosome data are included, they are often analyzed with suboptimal statistics. Several mathematically sensible statistics for X-chromosome association have been proposed. The optimality of these statistics, however, is based on very specific simple genetic models. In addition, while previous simulation studies of these statistics have been informative, they have focused on single-marker tests and have not considered the types of error that occur even under the null hypothesis when the entire X chromosome is scanned. In this study, we comprehensively tested several X-chromosome association statistics using simulation studies that include the entire chromosome. We also considered a wide range of trait models for sex differences and phenotypic effects of X inactivation. We found that models that do not incorporate a sex effect can have large type I error in some cases. We also found that many of the best statistics perform well even when there are modest deviations, such as trait variance differences between the sexes or small sex differences in allele frequencies, from assumptions. © 2018 WILEY PERIODICALS, INC.

  3. An extensive allelic series of Drosophila kae1 mutants reveals diverse and tissue-specific requirements for t6A biogenesis

    Science.gov (United States)

    Lin, Ching-Jung; Smibert, Peter; Zhao, Xiaoyu; Hu, Jennifer F.; Ramroop, Johnny; Kellner, Stefanie M.; Benton, Matthew A.; Govind, Shubha; Dedon, Peter C.; Sternglanz, Rolf; Lai, Eric C.

    2015-01-01

    N6-threonylcarbamoyl-adenosine (t6A) is one of the few RNA modifications that is universally present in life. This modification occurs at high frequency at position 37 of most tRNAs that decode ANN codons, and stabilizes cognate anticodon–codon interactions. Nearly all genetic studies of the t6A pathway have focused on single-celled organisms. In this study, we report the isolation of an extensive allelic series in the Drosophila ortholog of the core t6A biosynthesis factor Kae1. kae1 hemizygous larvae exhibit decreases in t6A that correlate with allele strength; however, we still detect substantial t6A-modified tRNAs even during the extended larval phase of null alleles. Nevertheless, complementation of Drosophila Kae1 and other t6A factors in corresponding yeast null mutants demonstrates that these metazoan genes execute t6A synthesis. Turning to the biological consequences of t6A loss, we characterize prominent kae1 melanotic masses and show that they are associated with lymph gland overgrowth and ectopic generation of lamellocytes. On the other hand, kae1 mutants exhibit other phenotypes that reflect insufficient tissue growth. Interestingly, whole-tissue and clonal analyses show that strongly mitotic tissues such as imaginal discs are exquisitely sensitive to loss of kae1, whereas nonproliferating tissues are less affected. Indeed, despite overt requirements of t6A for growth of many tissues, certain strong kae1 alleles achieve and sustain enlarged body size during their extended larval phase. Our studies highlight tissue-specific requirements of the t6A pathway in a metazoan context and provide insights into the diverse biological roles of this fundamental RNA modification during animal development and disease. PMID:26516084

  4. Formation and Expansion of Leukemia-Specific Chromosome Aberrations in Hematopoietic Cells of X-ray Irradiated Mice

    International Nuclear Information System (INIS)

    Ban, N.; Kai, M.; Kusama, T.

    2004-01-01

    C3H/He mice develop acute myeloid leukemia (AML) after whole-body irradiation, and typical chromosome 2 deletions are found in the leukemia cells. To investigate a process of the formation and the expansion of the AML-specific deletions, we have examined its frequency in primitive hematopoietic cells that could be the target of the leukemogenesis. Male C3H/He mice were exposed to 3Gy x-rays and sacrificed after certain periods of time. Bone marrow cells were collected from the femora and a single-cell suspension from each animal was divided into two parts. One part of the cell suspension was cultured in methylcellulose medium and metaphase spreads were prepared from each growing colony. The other part was sorted to obtain Lin+ and Lin Scal cells and those cells were scored with FISH for the AML-specific deletions. Karyotyping of the cultured cells detected signs of the delayed chromosomal instability, but an aberration involving chromosome 2 has not been found so far. FISH to the sorted cells, however, revealed the ANL-specific deletions could be produced in the primitive hematopoietic cells as an early event of radiation exposure. (Author) 16 refs

  5. Over-representation of specific regions of chromosome 22 in cells from human glioma correlate with resistance to 1,3-bis(2-chloroethyl)-1-nitrosourea

    International Nuclear Information System (INIS)

    Hank, Nicole C; Shapiro, Joan Rankin; Scheck, Adrienne C

    2006-01-01

    Glioblastoma multiforme is the most malignant form of brain tumor. Despite treatment including surgical resection, adjuvant chemotherapy, and radiation, these tumors typically recur. The recurrent tumor is often resistant to further therapy with the same agent, suggesting that the surviving cells that repopulate the tumor mass have an intrinsic genetic advantage. We previously demonstrated that cells selected for resistance to 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) are near-diploid, with over-representation of part or all of chromosomes 7 and 22. While cells from untreated gliomas often have over-representation of chromosome 7, chromosome 22 is typically under-represented. We have analyzed cells from primary and recurrent tumors from the same patient before and after in vitro selection for resistance to clinically relevant doses of BCNU. Karyotypic analyses were done to demonstrate the genetic makeup of these cells, and fluorescent in situ hybridization analyses have defined the region(s) of chromosome 22 retained in these BCNU-resistant cells. Karyotypic analyses demonstrated that cells selected for BCNU resistance were near-diploid with over-representation of chromosomes 7 and 22. In cells where whole copies of chromosome 22 were not identified, numerous fragments of this chromosome were retained and inserted into several marker and derivative chromosomes. Fluorescent in situ hybridization analyses using whole chromosome paints confirmed this finding. Additional FISH analysis using bacterial artificial chromosome probes spanning the length of chromosome 22 have allowed us to map the over-represented region to 22q12.3–13.32. Cells selected for BCNU resistance either in vivo or in vitro retain sequences mapped to chromosome 22. The specific over-representation of sequences mapped to 22q12.3–13.32 suggest the presence of a DNA sequence important to BCNU survival and/or resistance located in this region of chromosome 22

  6. Untangling the Contributions of Sex-Specific Gene Regulation and X-Chromosome Dosage to Sex-Biased Gene Expression in Caenorhabditis elegans

    Science.gov (United States)

    Kramer, Maxwell; Rao, Prashant; Ercan, Sevinc

    2016-01-01

    Dosage compensation mechanisms equalize the level of X chromosome expression between sexes. Yet the X chromosome is often enriched for genes exhibiting sex-biased, i.e., imbalanced expression. The relationship between X chromosome dosage compensation and sex-biased gene expression remains largely unexplored. Most studies determine sex-biased gene expression without distinguishing between contributions from X chromosome copy number (dose) and the animal’s sex. Here, we uncoupled X chromosome dose from sex-specific gene regulation in Caenorhabditis elegans to determine the effect of each on X expression. In early embryogenesis, when dosage compensation is not yet fully active, X chromosome dose drives the hermaphrodite-biased expression of many X-linked genes, including several genes that were shown to be responsible for hermaphrodite fate. A similar effect is seen in the C. elegans germline, where X chromosome dose contributes to higher hermaphrodite X expression, suggesting that lack of dosage compensation in the germline may have a role in supporting higher expression of X chromosomal genes with female-biased functions in the gonad. In the soma, dosage compensation effectively balances X expression between the sexes. As a result, somatic sex-biased expression is almost entirely due to sex-specific gene regulation. These results suggest that lack of dosage compensation in different tissues and developmental stages allow X chromosome copy number to contribute to sex-biased gene expression and function. PMID:27356611

  7. Population genetics of Phytophthora infestans in Denmark reveals dominantly clonal populations and specific alleles linked to metalaxyl-M resistance

    DEFF Research Database (Denmark)

    Montes, M. S.; Nielsen, Bent Jørgen; Schmidt, S. G.

    2016-01-01

    population of P. infestans was characterized over the course of the 2013 growing season, as was the population genetic structure, using simple sequence repeat (SSR) genotypes and single nucleotide polymorphism (SNP)-based mitochondrial haplotyping of over 80 isolates. Both mating types A1 and A2 were present...... in most fields, but tests for recombination showed that clonal reproduction dominates in Danish populations. Genotype was not linked to haplotype and no differentiation was observed at the haplotype level, but rather between fields. Resistance phenotypes were linked to specific SSR alleles, demonstrating...

  8. Swine Leukocyte Antigen (SLA) class I allele typing of Danish swine herds and identification of commonly occurring haplotypes using sequence specific low and high resolution primers

    DEFF Research Database (Denmark)

    Pedersen, Lasse Eggers; Jungersen, Gregers; Sørensen, Maria Rathmann

    2014-01-01

    of such peptide-MHC complexes (pMHC) naïve T cells can become activated and respond to a given pathogen leading to its elimination and the generation of memory cells. Hence SLA plays a crucial role in maintaining overall adaptive immunologic resistance to pathogens. Knowing which SLA alleles that are commonly...... occurring can be of great importance in regard to future vaccine development and the establishment of immune protection in swine through broad coverage, highly specific, subunit based vaccination against viruses such as swine influenza, porcine reproductive and respiratory syndrome virus, vesicular...

  9. Development of Chromosome-Specific BAC Resources for Genomics of Bread Wheat

    Czech Academy of Sciences Publication Activity Database

    Šafář, Jan; Šimková, Hana; Kubaláková, Marie; Čihalíková, Jarmila; Suchánková, Pavla; Bartoš, Jan; Doležel, Jaroslav

    2010-01-01

    Roč. 129, 1-3 (2010), s. 211-223 ISSN 1424-8581 R&D Projects: GA ČR GA521/07/1573; GA MŠk(CZ) LC06004 Grant - others:European Community’s Seventh Framework Programme(XE) FP7/2007–2013 Institutional research plan: CEZ:AV0Z50380511 Keywords : BAC library * Chromosome * DNA markers Subject RIV: GE - Plant Breeding Impact factor: 1.783, year: 2010

  10. Transposable elements generate population-specific insertional patterns and allelic variation in genes of wild emmer wheat (Triticum turgidum ssp. dicoccoides).

    Science.gov (United States)

    Domb, Katherine; Keidar, Danielle; Yaakov, Beery; Khasdan, Vadim; Kashkush, Khalil

    2017-10-27

    Natural populations of the tetraploid wild emmer wheat (genome AABB) were previously shown to demonstrate eco-geographically structured genetic and epigenetic diversity. Transposable elements (TEs) might make up a significant part of the genetic and epigenetic variation between individuals and populations because they comprise over 80% of the wild emmer wheat genome. In this study, we performed detailed analyses to assess the dynamics of transposable elements in 50 accessions of wild emmer wheat collected from 5 geographically isolated sites. The analyses included: the copy number variation of TEs among accessions in the five populations, population-unique insertional patterns, and the impact of population-unique/specific TE insertions on structure and expression of genes. We assessed the copy numbers of 12 TE families using real-time quantitative PCR, and found significant copy number variation (CNV) in the 50 wild emmer wheat accessions, in a population-specific manner. In some cases, the CNV difference reached up to 6-fold. However, the CNV was TE-specific, namely some TE families showed higher copy numbers in one or more populations, and other TE families showed lower copy numbers in the same population(s). Furthermore, we assessed the insertional patterns of 6 TE families using transposon display (TD), and observed significant population-specific insertional patterns. The polymorphism levels of TE-insertional patterns reached 92% among all wild emmer wheat accessions, in some cases. In addition, we observed population-specific/unique TE insertions, some of which were located within or close to protein-coding genes, creating allelic variations in a population-specific manner. We also showed that those genes are differentially expressed in wild emmer wheat. For the first time, this study shows that TEs proliferate in wild emmer wheat in a population-specific manner, creating new alleles of genes, which contribute to the divergent evolution of homeologous genes

  11. SAAS-CNV: A Joint Segmentation Approach on Aggregated and Allele Specific Signals for the Identification of Somatic Copy Number Alterations with Next-Generation Sequencing Data.

    Science.gov (United States)

    Zhang, Zhongyang; Hao, Ke

    2015-11-01

    Cancer genomes exhibit profound somatic copy number alterations (SCNAs). Studying tumor SCNAs using massively parallel sequencing provides unprecedented resolution and meanwhile gives rise to new challenges in data analysis, complicated by tumor aneuploidy and heterogeneity as well as normal cell contamination. While the majority of read depth based methods utilize total sequencing depth alone for SCNA inference, the allele specific signals are undervalued. We proposed a joint segmentation and inference approach using both signals to meet some of the challenges. Our method consists of four major steps: 1) extracting read depth supporting reference and alternative alleles at each SNP/Indel locus and comparing the total read depth and alternative allele proportion between tumor and matched normal sample; 2) performing joint segmentation on the two signal dimensions; 3) correcting the copy number baseline from which the SCNA state is determined; 4) calling SCNA state for each segment based on both signal dimensions. The method is applicable to whole exome/genome sequencing (WES/WGS) as well as SNP array data in a tumor-control study. We applied the method to a dataset containing no SCNAs to test the specificity, created by pairing sequencing replicates of a single HapMap sample as normal/tumor pairs, as well as a large-scale WGS dataset consisting of 88 liver tumors along with adjacent normal tissues. Compared with representative methods, our method demonstrated improved accuracy, scalability to large cancer studies, capability in handling both sequencing and SNP array data, and the potential to improve the estimation of tumor ploidy and purity.

  12. Genome-wide identification and quantification of cis- and trans-regulated genes responding to Marek’s disease virus infection via analysis of allele-specific expression

    Directory of Open Access Journals (Sweden)

    Sean eMaceachern

    2012-01-01

    Full Text Available Marek’s disease (MD is a commercially important neoplastic disease of chickens caused by Marek’s disease virus (MDV, an oncogenic alphaherpesvirus. Selecting for increased genetic resistance to MD is a control strategy that can augment vaccinal control measures. To identify high-confidence candidate MD resistance genes, we conducted a genome-wide screen for allele-specific expression (ASE amongst F1 progeny of two inbred chicken lines that differ in MD resistance. High throughput sequencing was used to profile transcriptomes from pools of uninfected and infected individuals at 4 days post-infection to identify any genes showing ASE in response to MDV infection. RNA sequencing identified 22,655 single nucleotide polymorphisms (SNPs of which 5,360 in 3,773 genes exhibited significant allelic imbalance. Illumina GoldenGate assays were subsequently used to quantify regulatory variation controlled at the gene (cis and elsewhere in the genome (trans by examining differences in expression between F1 individuals and artificial F1 RNA pools over 6 time periods in 1,536 of the most significant SNPs identified by RNA sequencing. Allelic imbalance as a result of cis-regulatory changes was confirmed in 861 of the 1,233 GoldenGate assays successfully examined. Furthermore we have identified 7 genes that display trans-regulation only in infected animals and approximately 500 SNP that show a complex interaction between cis- and trans-regulatory changes. Our results indicate ASE analyses are a powerful approach to identify regulatory variation responsible for differences in transcript abundance in genes underlying complex traits. And the genes with SNPs exhibiting ASE provide a strong foundation to further investigate the causative polymorphisms and genetic mechanisms for MD resistance. Finally, the methods used here for identifying specific genes and SNPs may have practical implications for applying marker-assisted selection to complex traits that are

  13. Altered expression of testis-specific genes, piRNAs, and transposons in the silkworm ovary masculinized by a W chromosome mutation

    Science.gov (United States)

    2012-01-01

    Background In the silkworm, Bombyx mori, femaleness is strongly controlled by the female-specific W chromosome. Originally, it was presumed that the W chromosome encodes female-determining gene(s), accordingly called Fem. However, to date, neither Fem nor any protein-coding gene has been identified from the W chromosome. Instead, the W chromosome is occupied with numerous transposon-related sequences. Interestingly, the silkworm W chromosome is a source of female-enriched PIWI-interacting RNAs (piRNAs). piRNAs are small RNAs of 23-30 nucleotides in length, which are required for controlling transposon activity in animal gonads. A recent study has identified a novel mutant silkworm line called KG, whose mutation in the W chromosome causes severe female masculinization. However, the molecular nature of KG line has not been well characterized yet. Results Here we molecularly characterize the KG line. Genomic PCR analyses using currently available W chromosome-specific PCR markers indicated that no large deletion existed in the KG W chromosome. Genetic analyses demonstrated that sib-crosses within the KG line suppressed masculinization. Masculinization reactivated when crossing KG females with wild type males. Importantly, the KG ovaries exhibited a significantly abnormal transcriptome. First, the KG ovaries misexpressed testis-specific genes. Second, a set of female-enriched piRNAs was downregulated in the KG ovaries. Third, several transposons were overexpressed in the KG ovaries. Conclusions Collectively, the mutation in the KG W chromosome causes broadly altered expression of testis-specific genes, piRNAs, and transposons. To our knowledge, this is the first study that describes a W chromosome mutant with such an intriguing phenotype. PMID:22452797

  14. SU94. Allele-Specific and Trauma-Related Epigenetic Changes in the FKBP5 Gene: Differences Between Psychotic Patients and Healthy Controls

    Science.gov (United States)

    Mihaljevic, Marina; Franic, Dusica; Soldatovic, Ivan; Andric, Sanja; Mirjanic, Tijana; Novakovic, Ivana; Adzic, Miroslav; Maric, Nadja

    2017-01-01

    Abstract Background: Hypothalamic-pituitary-adrenal (HPA) axis dysregulation is a proposed etiological mechanism of psychosis. Recent studies highlighted impact of the FKBP5 gene and its functional variant rs1360780, which risk (T) allele affects the activity of HPA axis following stress exposure, on psychotic patients exposed to early trauma (1). Additionally, risk allele and trauma dependent FKBP5 demethylation in intron 7 was observed in traumatized individuals (2). Thus, the purpose of this pilot study was to investigate influence of the risk allele and trauma on FKBP5 DNA methylation levels at intron 7 in psychotic patients and to compare it with healthy individuals. Methods: The sample consisted of 24 psychosis spectrum patients and 24 controls matched by age and gender. All participants were genotyped for rs1360780 and divided into 2 groups depending on the presence of the risk allele (risk and nonrisk group). DNA methylation levels at 3 CpG sites (CpG1, CpG2, and CpG3) in intron 7 were analyzed by Sanger sequencing. Early-life adversities were measured by Childhood Trauma Questionnaire. Pearson correlation and t test were performed as appropriate. Results: Analyses revealed decreased FKBP5 methylation at targeted CpG sites and averaged methylation level (AML) at intron 7 in patients compared to controls (P = .026, P = .017, P = .027, and P = .003, respectively). Decreased AML and methylation at CpG3 were observed comparing risk and nonrisk patients’ groups (P = .018 and P = .016, respectively). Additionally, decreased methylation was found in risk patients’ group compared to risk controls’ group. No differences were found comparing nonrisk groups. Furthermore, strong negative associations between trauma and methylation at CpG3 and AML were observed only in risk controls’ group (r = −0.707, P = .007; r = −0.741, P = .004, respectively). Conclusion: Our preliminary results revealed allele-specific epigenetic changes of the FKBP

  15. Identification of a Novel Retrotransposon with Sex Chromosome-Specific Distribution in Silene latifolia

    Czech Academy of Sciences Publication Activity Database

    Králová, Tereza; Čegan, Radim; Kubát, Zdeněk; Vrána, Jan; Vyskot, Boris; Vogel, Ivan; Kejnovský, Eduard; Hobza, Roman

    2014-01-01

    Roč. 143, 1-3 (2014), s. 87-95 ISSN 1424-8581 R&D Projects: GA MŠk(CZ) LM2010005; GA ČR(CZ) GAP501/10/0102; GA ČR(CZ) GAP501/12/2220; GA ČR(CZ) GAP305/10/0930; GA ČR(CZ) GA522/09/0083; GA MŠk(CZ) LO1204 Institutional support: RVO:68081707 Keywords : Microdissection * Sex chromosomes * Silene latifolia (white campion) Subject RIV: BO - Biophysics; EF - Botanics (UEB-Q) Impact factor: 1.561, year: 2014

  16. Duplications of the Y-chromosome specific loci P25 and 92R7 and forensic implications

    DEFF Research Database (Denmark)

    Sanchez Sanchez, Juan Jose; Brión, Maria; Parson, Walther

    2004-01-01

    methodologies were used in order to detect the SNP alleles and the PSVs of the loci. All results obtained with the various typing techniques supported the conclusion. The allele distributions of the binary markers were analysed in more than 600 males with seven different haplogroups. For P25, the ancestral...... allele C was found in several samples from different haplogroups. The derived allele A was always present with an additional C variant. Haplogroup P was defined by the derived allele A at the 92R7 locus. However, the ancestral allele G was always associated with an A variant due to the duplication....

  17. Utilization of a ts-sacB selection system for the generation of a Mycobacterium avium serovar-8 specific glycopeptidolipid allelic exchange mutant

    Science.gov (United States)

    Irani, Vida R; Lee, Sun-Hwa; Eckstein, Torsten M; Inamine, Julia M; Belisle, John T; Maslow, Joel N

    2004-01-01

    Background Mycobacterium avium are ubiquitous environmental organisms and a cause of disseminated infection in patients with end-stage AIDS. The glycopeptidolipids (GPL) of M. avium are proposed to participate in the pathogenesis of this organism, however, establishment of a clear role for GPL in disease production has been limited by the inability to genetically manipulate M. avium. Methods To be able to study the role of the GPL in M. avium pathogenesis, a ts-sacB selection system, not previously used in M. avium, was employed as a means to achieve homologous recombination for the rhamnosyltransferase (rtfA) gene of a pathogenic serovar 8 strain of M. avium to prevent addition of serovar-specific sugars to rhamnose of the fatty acyl-peptide backbone of GPL. The genotype of the resultant rtfA mutant was confirmed by polymerase chain reaction and southern hybridization. Disruption in the proximal sugar of the haptenic oligosaccharide resulted in the loss of serovar specific GPL with no change in the pattern of non-serovar specific GPL moieties as shown by thin layer chromatography and gas chromatography/mass spectrometry. Complementation of wild type (wt) rtfA in trans through an integrative plasmid restored serovar-8 specific GPL expression identical to wt serovar 8 parent strain. Results In this study, we affirm our results that rtfA encodes an enzyme responsible for the transfer of Rha to 6d-Tal and provide evidence of a second allelic exchange mutagenesis system suitable for M. avium. Conclusion We report the second allelic exchange system for M. avium utilizing ts-sacB as double-negative and xylE as positive counter-selection markers, respectively. This system of allelic exchange would be especially useful for M. avium strains that demonstrate significant isoniazid (INH) resistance despite transformation with katG. Through the construction of mutants in GPL or other mycobacterial components, their roles in M. avium pathogenesis, biosynthesis, or drug

  18. Utilization of a ts-sacB selection system for the generation of a Mycobacterium avium serovar-8 specific glycopeptidolipid allelic exchange mutant

    Directory of Open Access Journals (Sweden)

    Belisle John T

    2004-09-01

    Full Text Available Abstract Background Mycobacterium avium are ubiquitous environmental organisms and a cause of disseminated infection in patients with end-stage AIDS. The glycopeptidolipids (GPL of M. avium are proposed to participate in the pathogenesis of this organism, however, establishment of a clear role for GPL in disease production has been limited by the inability to genetically manipulate M. avium. Methods To be able to study the role of the GPL in M. avium pathogenesis, a ts-sacB selection system, not previously used in M. avium, was employed as a means to achieve homologous recombination for the rhamnosyltransferase (rtfA gene of a pathogenic serovar 8 strain of M. avium to prevent addition of serovar-specific sugars to rhamnose of the fatty acyl-peptide backbone of GPL. The genotype of the resultant rtfA mutant was confirmed by polymerase chain reaction and southern hybridization. Disruption in the proximal sugar of the haptenic oligosaccharide resulted in the loss of serovar specific GPL with no change in the pattern of non-serovar specific GPL moieties as shown by thin layer chromatography and gas chromatography/mass spectrometry. Complementation of wild type (wt rtfA in trans through an integrative plasmid restored serovar-8 specific GPL expression identical to wt serovar 8 parent strain. Results In this study, we affirm our results that rtfA encodes an enzyme responsible for the transfer of Rha to 6d-Tal and provide evidence of a second allelic exchange mutagenesis system suitable for M. avium. Conclusion We report the second allelic exchange system for M. avium utilizing ts-sacB as double-negative and xylE as positive counter-selection markers, respectively. This system of allelic exchange would be especially useful for M. avium strains that demonstrate significant isoniazid (INH resistance despite transformation with katG. Through the construction of mutants in GPL or other mycobacterial components, their roles in M. avium pathogenesis

  19. Concordance of the ForenSeq™ system and characterisation of sequence-specific autosomal STR alleles across two major population groups.

    Science.gov (United States)

    Devesse, Laurence; Ballard, David; Davenport, Lucinda; Riethorst, Immy; Mason-Buck, Gabriella; Syndercombe Court, Denise

    2018-05-01

    By using sequencing technology to genotype loci of forensic interest it is possible to simultaneously target autosomal, X and Y STRs as well as identity, ancestry and phenotypic informative SNPs, resulting in a breadth of data obtained from a single run that is considerable when compared to that generated with standard technologies. It is important however that this information aligns with the genotype data currently obtained using commercially available kits for CE-based investigations such that results are compatible with existing databases and hence can be of use to the forensic community. In this work, 400 samples were typed using commercially available STR kits and CE, as well as using the Ilumina ForenSeq™ DNA Signature Prep Kit and MiSeq ® FGx to assess concordance of autosomal STRs and population variability. Results show a concordance rate between the two technologies exceeding 99.98% while numerous novel sequence based alleles are described. In order to make use of the sequence variation observed, sequence specific allele frequencies were generated for White British and British Chinese populations. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Novel polymorphisms within the Dlk1-Dio3 imprinted locus in rat: a putative genetic basis for strain-specific allelic gene expression

    Directory of Open Access Journals (Sweden)

    Laura J Sittig

    2012-12-01

    Full Text Available The imprinted iodothyronine deiodinase-III (Dio3 thyroid hormone metabolizing gene exhibits paternal expression in most fetal tissues, yet exhibits aberrant, maternal expression in the hippocampus in F1 offspring of Sprague Dawley (SD x Brown Norway (BN rats. The maternal hippocampal expression is associated with lower Dio3 mRNA levels specifically in the hippocampus. Here, we tested the hypothesis that genetic polymorphisms between the SD and BN parent strains cause this aberrant allelic Dio3 expression and contribute to behavioral sequelae of higher thyroid hormone levels locally in the hippocampus, including anxiety-related behavior. We mapped and sequenced the Dio3 gene and several previously unmapped regions in the Dlk1-Dio3 locus that could regulate imprinting of the Dio3 gene. In the Dio3 promoter we identified four novel polymorphisms between the BN and SD strains. Next we took advantage of the fact that the Long Evans (LE strain exhibits identical polymorphisms as the SD strain in the region 5’ and including the Dio3 gene. By reciprocally crossing LE and BN strains we tested the relationship among Dio3 promoter region polymorphisms and Dio3 mRNA expression in the hippocampus. Aberrant strain-specific hippocampal Dio3 allelic expression replicated in the LE-BN reciprocal crosses, suggesting that hippocampal-specific imprinting of the Dio3 gene is not the result of a unique genetic or epigenetic characteristic of the SD rat strain, or a unique epistatic interaction between SD and BN. To our knowledge no other studies have reported a genetic x epigenetic interaction of genetic origin in the brain.

  1. Detection of EGFR mutations in plasma and biopsies from non-small cell lung cancer patients by allele-specific PCR assays

    DEFF Research Database (Denmark)

    Weber, Britta; Meldgaard, Peter; Hager, Henrik

    2014-01-01

    samples with allele-specific PCR assays. METHODS: Pairs of the diagnostic biopsy and plasma obtained just prior to start of erlotinib treatment were collected from 199 patients with adenocarcinoma of non-small-cell lung cancer. DNA from both sample types was isolated and examined for the presence...... of mutations in exons 18-21 of the EGFR gene, employing the cobas(®) EGFR Tissue Test and cobas(®) EGFR Blood Test (in development, Roche Molecular Systems, Inc., CA, USA). RESULTS: Test results were obtained in all 199 (100%) plasma samples and 196/199 (98%) of the biopsies. EGFR-activating mutations were...... identified in 24/199 (12%) plasma samples and 28/196 (14%) biopsy samples, and 17/196 (9%) matched pairs contained the same mutation. Six EGFR mutations were present only in plasma samples but not in the biopsy samples. The overall concordance of the EGFR gene mutations detected in plasma and biopsy tissue...

  2. Mutant Allele-Specific Uncoupling of PENETRATION3 Functions Reveals Engagement of the ATP-Binding Cassette Transporter in Distinct Tryptophan Metabolic Pathways1[OPEN

    Science.gov (United States)

    Lu, Xunli; Dittgen, Jan; Piślewska-Bednarek, Mariola; Molina, Antonio; Schneider, Bernd; Doubský, Jan; Schneeberger, Korbinian; Schulze-Lefert, Paul

    2015-01-01

    Arabidopsis (Arabidopsis thaliana) PENETRATION (PEN) genes quantitatively contribute to the execution of different forms of plant immunity upon challenge with diverse leaf pathogens. PEN3 encodes a plasma membrane-resident pleiotropic drug resistance-type ATP-binding cassette transporter and is thought to act in a pathogen-inducible and PEN2 myrosinase-dependent metabolic pathway in extracellular defense. This metabolic pathway directs the intracellular biosynthesis and activation of tryptophan-derived indole glucosinolates for subsequent PEN3-mediated efflux across the plasma membrane at pathogen contact sites. However, PEN3 also functions in abiotic stress responses to cadmium and indole-3-butyric acid (IBA)-mediated auxin homeostasis in roots, raising the possibility that PEN3 exports multiple functionally unrelated substrates. Here, we describe the isolation of a pen3 allele, designated pen3-5, that encodes a dysfunctional protein that accumulates in planta like wild-type PEN3. The specific mutation in pen3-5 uncouples PEN3 functions in IBA-stimulated root growth modulation, callose deposition induced with a conserved peptide epitope of bacterial flagellin (flg22), and pathogen-inducible salicylic acid accumulation from PEN3 activity in extracellular defense, indicating the engagement of multiple PEN3 substrates in different PEN3-dependent biological processes. We identified 4-O-β-d-glucosyl-indol-3-yl formamide (4OGlcI3F) as a pathogen-inducible, tryptophan-derived compound that overaccumulates in pen3 leaf tissue and has biosynthesis that is dependent on an intact PEN2 metabolic pathway. We propose that a precursor of 4OGlcI3F is the PEN3 substrate in extracellular pathogen defense. These precursors, the shared indole core present in IBA and 4OGlcI3F, and allele-specific uncoupling of a subset of PEN3 functions suggest that PEN3 transports distinct indole-type metabolites in distinct biological processes. PMID:26023163

  3. Molecular cytogenetic analysis of Inv Dup(15) chromosomes, using probes specific for the Pradar-Willi/Angelman syndrome region: Clinical implications

    Energy Technology Data Exchange (ETDEWEB)

    Leana-Cox, J. (Univ. of Maryland School of Medicine, Baltimore, MD (United States)); Jenkins, L. (Kaiser Permanente Medical Group, San Jose, CA (United States)); Palmer, C.G.; Plattner, R. (Indiana School of Medicine, Indianapolis, IN (United States)); Sheppard, L. (Palo Verde Laboratory, Inc., Chandler, AZ (United States)); Flejter, W.L. (Univ. of Michigan, Ann Arbor, MI (United States)); Zackowski, J. (Univ. of Florida Health Science Center, Gainsville, FL (United States)); Tsien, F. (Tulane Univ. School of Medicine, New Orleans, LA (United States)); Schwartz, S. (Case Western Reserve Univ., Cleveland, OH (United States))

    1994-05-01

    Twenty-seven cases of inverted duplications of chromosome 15 (inv dup[15]) were investigated by FISH with two DNA probes specific for the Prader-Willi syndrome/Angelman syndrome (PWS/AS) region on proximal 15q. Sixteen of the marker chromosomes displayed two copies of each probe, while in the remaining 11 markers no hybridization was observed. A significant association was found between the presence of this region and an abnormal phenotype (P<.01). This is the largest study to date of inv dup(15) chromosomes, that uses molecular cytogenetic methods and is the first to report a significant association between the presence of a specific chromosomal region in such markers and an abnormal phenotype. 30 refs., 1 fig., 4 tabs.

  4. Reliable allele detection using SNP-based PCR primers containing Locked Nucleic Acid: application in genetic mapping

    Directory of Open Access Journals (Sweden)

    Trognitz Friederike

    2007-02-01

    Full Text Available Abstract Background The diploid, Solanum caripense, a wild relative of potato and tomato, possesses valuable resistance to potato late blight and we are interested in the genetic base of this resistance. Due to extremely low levels of genetic variation within the S. caripense genome it proved impossible to generate a dense genetic map and to assign individual Solanum chromosomes through the use of conventional chromosome-specific SSR, RFLP, AFLP, as well as gene- or locus-specific markers. The ease of detection of DNA polymorphisms depends on both frequency and form of sequence variation. The narrow genetic background of close relatives and inbreds complicates the detection of persisting, reduced polymorphism and is a challenge to the development of reliable molecular markers. Nonetheless, monomorphic DNA fragments representing not directly usable conventional markers can contain considerable variation at the level of single nucleotide polymorphisms (SNPs. This can be used for the design of allele-specific molecular markers. The reproducible detection of allele-specific markers based on SNPs has been a technical challenge. Results We present a fast and cost-effective protocol for the detection of allele-specific SNPs by applying Sequence Polymorphism-Derived (SPD markers. These markers proved highly efficient for fingerprinting of individuals possessing a homogeneous genetic background. SPD markers are obtained from within non-informative, conventional molecular marker fragments that are screened for SNPs to design allele-specific PCR primers. The method makes use of primers containing a single, 3'-terminal Locked Nucleic Acid (LNA base. We demonstrate the applicability of the technique by successful genetic mapping of allele-specific SNP markers derived from monomorphic Conserved Ortholog Set II (COSII markers mapped to Solanum chromosomes, in S. caripense. By using SPD markers it was possible for the first time to map the S. caripense alleles

  5. Over half of breakpoints in gene pairs involved in cancer-specific recurrent translocations are mapped to human chromosomal fragile sites

    Directory of Open Access Journals (Sweden)

    Pierce Levi CT

    2009-01-01

    Full Text Available Abstract Background Gene rearrangements such as chromosomal translocations have been shown to contribute to cancer development. Human chromosomal fragile sites are regions of the genome especially prone to breakage, and have been implicated in various chromosome abnormalities found in cancer. However, there has been no comprehensive and quantitative examination of the location of fragile sites in relation to all chromosomal aberrations. Results Using up-to-date databases containing all cancer-specific recurrent translocations, we have examined 444 unique pairs of genes involved in these translocations to determine the correlation of translocation breakpoints and fragile sites in the gene pairs. We found that over half (52% of translocation breakpoints in at least one gene of these gene pairs are mapped to fragile sites. Among these, we examined the DNA sequences within and flanking three randomly selected pairs of translocation-prone genes, and found that they exhibit characteristic features of fragile DNA, with frequent AT-rich flexibility islands and the potential of forming highly stable secondary structures. Conclusion Our study is the first to examine gene pairs involved in all recurrent chromosomal translocations observed in tumor cells, and to correlate the location of more than half of breakpoints to positions of known fragile sites. These results provide strong evidence to support a causative role for fragile sites in the generation of cancer-specific chromosomal rearrangements.

  6. Construction of a DNA library representing 15q11-13 by subtraction of two flow sorted marker chromosome-specific libraries

    Energy Technology Data Exchange (ETDEWEB)

    Blennow, E.; Werelius, B.; Nordenskjoeld, M. [Karolinska Hospital, Stockholm (Sweden)] [and others

    1994-09-01

    Constitutional extra {open_quotes}marker chromosomes{close_quotes} are found in {approx}0.5/1000 of newborns. Of these, 50% are inverted duplications of the pericentromeric region of chromosome 15, including two variants; (1) inv dup(15)(pter{yields}q11:q11{yields}pter) and (2) inv dup(15) (pter{yields}q12-13::q12-13{yields}pter). Variant (1) is found in phenotypically normal individuals, whereas variant (2) will produce a typical clinical picture including mental retardation, autism, hyperactivity and discrete dysmorphic features. Fluorescence in situ hybridization (FISH) using single copy probes from the Prader-Willi region confirms these observations as well as chromosome painting using a flow-sorted marker chromosome-specific library from a variant (1) marker, hybridized to the chromosomes of a patient with a variant (2) marker chromosome. Followingly, a flow-sorted biotinylated variant (1) library was subtracted from a non-labeled variant (2) library using magnetic beads and subsequent amplification by degenerate oligonucleotide-primed PCR (DOP-PCR). The successful result was demonstrated by using the amplified material for chromosome painting on chromosome slides from variant (1) and variant (2) patients. We have constructed a library from 15q11-13. This region contains genes producing a specific abnormal phenotype when found in a tri- or tetrasomic state. The region also contains the genes responsible for the Prader-Willi and Angelman syndromes when the paternal/maternal copy is missing, respectively. It is therefore a region where parental imprinting plays an important role. The isolated library may be used to isolate single copy clones which will allow further investigations of this region.

  7. Evaluation of efficiency of nested multiplex allele-specific PCR assay for detection of multidrug resistant tuberculosis directly from sputum samples.

    Science.gov (United States)

    Mistri, S K; Sultana, M; Kamal, S M M; Alam, M M; Irin, F; Nessa, J; Ahsan, C R; Yasmin, M

    2016-05-01

    For an effective control of tuberculosis, rapid detection of multidrug resistant tuberculosis (MDR-TB) is necessary. Therefore, we developed a modified nested multiplex allele-specific polymerase chain reaction (MAS-PCR) method that enables rapid MDR-TB detection directly from sputum samples. The efficacy of this method was evaluated using 79 sputum samples collected from suspected tuberculosis patients. The performance of nested MAS-PCR method was compared with other MDR-TB detection methods like drug susceptibility testing (DST) and DNA sequencing. As rifampicin (RIF) resistance conforms to MDR-TB in greater than 90% cases, only the presence of RIF-associated mutations in rpoB gene was determined by DNA sequencing and nested MAS-PCR to detect MDR-TB. The concordance between nested MAS-PCR and DNA sequencing results was found to be 96·3%. When compared with DST, the sensitivity and specificity of nested MAS-PCR for RIF-resistance detection were determined to be 92·9 and 100% respectively. For developing- and high-TB burden countries, molecular-based tests have been recommended by the World Health Organization for rapid detection of MDR-TB. The results of this study indicate that, nested MAS-PCR assay might be a practical and relatively cost effective molecular method for rapid detection of MDR-TB from suspected sputum samples in developing countries with resource poor settings. © 2016 The Society for Applied Microbiology.

  8. 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

  9. 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-specific

  10. Tumor-specific loss of 11p15.5 alleles in del11p13 Wilms tumor and in familial adrenocortical carcinoma

    International Nuclear Information System (INIS)

    Henry, I.; Grandjouan, S.; Couillin, P.

    1989-01-01

    The authors have compared constitutional and tumor genotypes in nine cases of hereditary Wilms tumor (WT) and in three unrelated cases of familial adrenocortical carcinoma (ADCC). Since susceptibility to these tumors can be observed in malformation syndromes associated with a constitutional deletion of band 11p13 (WT) and with a constitutional duplication of band 11p15.5 (WT, ADCC), they investigated these two candidate regions by using 11p polymorphic markers. As expected, somatic chromosomal events, resulting in a loss of heterozygosity limited to region 11p15.5, were observed in the tumor of two familial cases of adrenocortical carcinoma. Surprisingly, however, analysis of the WT of two patients with a constitutional deletion of band 11p13, associated with aniridia, genitourinary abnormalities, and mental retardation (WAGR syndrome), revealed a loss of heterozygosity limited to region 11p15.5. These data therefore suggest that observation of a specific loss of heterozygosity may not necessarily point to the site of the initial germinal mutation. Together with previous similar observations of a loss of heterozygosity limited to 11p15.5 in breast cancer and in rhabdomyosarcoma, the data suggest that region 11p15.5 may carry a non-tissue-specific gene that could be involved in genetic predisposition, in tumor progression, or in both

  11. A specific insertion of a solo-LTR characterizes the Y-chromosome of Bryonia dioica (Cucurbitaceae).

    Science.gov (United States)

    Oyama, Ryan K; Silber, Martina V; Renner, Susanne S

    2010-06-14

    Relatively few species of flowering plants are dioecious and even fewer are known to have sex chromosomes. Current theory posits that homomorphic sex chromosomes, such as found in Bryonia dioica (Cucurbitaceae), offer insight into the early stages in the evolution of sex chromosomes from autosomes. Little is known about these early steps, but an accumulation of transposable element sequences has been observed on the Y-chromosomes of some species with heteromorphic sex chromosomes. Recombination, by which transposable elements are removed, is suppressed on at least part of the emerging Y-chromosome, and this may explain the correlation between the emergence of sex chromosomes and transposable element enrichment. We sequenced 2321 bp of the Y-chromosome in Bryonia dioica that flank a male-linked marker, BdY1, reported previously. Within this region, which should be suppressed for recombination, we observed a solo-LTR nested in a Copia-like transposable element. We also found other, presumably paralogous, solo-LTRs in a consensus sequence of the underlying Copia-like transposable element. Given that solo-LTRs arise via recombination events, it is noteworthy that we find one in a genomic region where recombination should be suppressed. Although the solo-LTR could have arisen before recombination was suppressed, creating the male-linked marker BdY1, our previous study on B. dioica suggested that BdY1 may not lie in the recombination-suppressed region of the Y-chromosome in all populations. Presence of a solo-LTR near BdY1 therefore fits with the observed correlation between retrotransposon accumulation and the suppression of recombination early in the evolution of sex chromosomes. These findings further suggest that the homomorphic sex chromosomes of B. dioica, the first organism for which genetic XY sex-determination was inferred, are evolutionarily young and offer reference information for comparative studies of other plant sex chromosomes.

  12. Long-distance interaction of the integrated HPV fragment with MYC gene and 8q24.22 region upregulating the allele-specific MYC expression in HeLa cells.

    Science.gov (United States)

    Shen, Congle; Liu, Yongzhen; Shi, Shu; Zhang, Ruiyang; Zhang, Ting; Xu, Qiang; Zhu, Pengfei; Chen, Xiangmei; Lu, Fengmin

    2017-08-01

    Human papillomavirus (HPV) infection is the most important risk factor for cervical cancer development. In HeLa cell line, the HPV viral genome is integrated at 8q24 in one allele of chromosome 8. It has been reported that the HPV fragment integrated in HeLa genome can cis-activate the expression of proto-oncogene MYC, which is located at 500 kb downstream of the integrated site. However, the underlying molecular mechanism of this regulation is unknown. A recent study reported that MYC was highly expressed exclusively from the HPV-integrated haplotype, and a long-range chromatin interaction between the integrated HPV fragment and MYC gene has been hypothesized. In this study, we provided the experimental evidences supporting this long-range chromatin interaction in HeLa cells by using Chromosome Conformation Capture (3C) method. We found that the integrated HPV fragment, MYC and 8q24.22 was close to each other and might form a trimer in spatial location. When knocking out the integrated HPV fragment or 8q24.22 region from chromosome 8 by CRISPR/Cas9 system, the expression of MYC reduced dramatically in HeLa cells. Interestingly, decreased expression was only observed in three from eight cell clones, when only one 8q24.22 allele was knocked out. Functionally, HPV knockout caused senescence-associated acidic β-gal activity in HeLa cells. These data indicate a long-distance interaction of the integrated HPV fragment with MYC gene and 8q24.22 region, providing an alternative mechanism relevant to the carcinogenicity of HPV integration. © 2017 The Authors International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.

  13. Allele specific hybridization using oligonucleotide probes of very high specific activity: Discrimination of the human β/sup A/ and β/sup S/-globin genes

    International Nuclear Information System (INIS)

    Studencki, A.B.; Wallace, R.B.

    1984-01-01

    The repair activity of E. coli DNA polymerase I (Klenow fragment) was used to prepare nonadecanucleotide hybridization probes which were complementary either to the normal human β-globin (β/sup A/) or to the sickle cell human β-globin (β/sup S/) gene. Template directed polymerization of highly radiolabeled α-/sup 32/P-deoxyribonucleoside triphosphates (3200, 5000 and/or 7800 Ci/mmol) onto nonamer and decamer primers produced probes with specific activities ranging from 1.0 - 2.0 x 10/sup 10/ dpm/μg. The extremely high specific activities of these probes made it possible to detect the β/sup A/ and β/sup S/ single copy gene sequences in as little as 1 μg of total human genomic DNA as well as to discriminate between the homozygous and heterozygous states. This means that it was possible to detect 0.5 - 1.0 x 10/sup -18/ moles of a given single copy sequence

  14. Specific down-regulation of spermatogenesis genes targeted by 22G RNAs in hybrid sterile males associated with an X-Chromosome introgression.

    Science.gov (United States)

    Li, Runsheng; Ren, Xiaoliang; Bi, Yu; Ho, Vincy Wing Sze; Hsieh, Chia-Ling; Young, Amanda; Zhang, Zhihong; Lin, Tingting; Zhao, Yanmei; Miao, Long; Sarkies, Peter; Zhao, Zhongying

    2016-09-01

    Hybrid incompatibility (HI) prevents gene flow between species, thus lying at the heart of speciation genetics. One of the most common HIs is male sterility. Two superficially contradictory observations exist for hybrid male sterility. First, an introgression on the X Chromosome is more likely to produce male sterility than on autosome (so-called large-X theory); second, spermatogenesis genes are enriched on the autosomes but depleted on the X Chromosome (demasculinization of X Chromosome). Analysis of gene expression in Drosophila hybrids suggests a genetic interaction between the X Chromosome and autosomes that is essential for male fertility. However, the prevalence of such an interaction and its underlying mechanism remain largely unknown. Here we examine the interaction in nematode species by contrasting the expression of both coding genes and transposable elements (TEs) between hybrid sterile males and its parental nematode males. We use two lines of hybrid sterile males, each carrying an independent introgression fragment from Caenorhabditis briggsae X Chromosome in an otherwise Caenorhabditis nigoni background, which demonstrate similar defects in spermatogenesis. We observe a similar pattern of down-regulated genes that are specific for spermatogenesis between the two hybrids. Importantly, the down-regulated genes caused by the X Chromosome introgressions show a significant enrichment on the autosomes, supporting an epistatic interaction between the X Chromosome and autosomes. We investigate the underlying mechanism of the interaction by measuring small RNAs and find that a subset of 22G RNAs specifically targeting the down-regulated spermatogenesis genes is significantly up-regulated in hybrids, suggesting that perturbation of small RNA-mediated regulation may contribute to the X-autosome interaction. © 2016 Li et al.; Published by Cold Spring Harbor Laboratory Press.

  15. A Family of Zinc Finger Proteins Is Required forChromosome-specific Pairing and Synapsis during Meiosis in C.elegans

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, Carolyn M.; Dernburg, Abby F.

    2006-06-07

    Homologous chromosome pairing and synapsis are prerequisitefor accurate chromosome segregation during meiosis. Here, we show that afamily of four related C2H2 zinc-finger proteins plays a central role inthese events in C. elegans. These proteins are encoded within a tandemgene cluster. In addition to the X-specific HIM-8 protein, threeadditional paralogs collectively mediate the behavior of the fiveautosomes. Each chromosome relies on a specific member of the family topair and synapse with its homolog. These "ZIM" proteins concentrate atspecial regions called meiotic pairing centers on the correspondingchromosomes. These sites are dispersed along the nuclear envelope duringearly meiotic prophase, suggesting a role analogous to thetelomere-mediated meiotic bouquet in other organisms. To gain insightinto the evolution of these components, wecharacterized homologs in C.briggsae and C. remanei, which revealed changes in copy number of thisgene family within the nematode lineage.

  16. Trans-ethnic fine-mapping of lipid loci identifies population-specific signals and allelic heterogeneity that increases the trait variance explained.

    Directory of Open Access Journals (Sweden)

    Ying Wu

    2013-03-01

    Full Text Available Genome-wide association studies (GWAS have identified ~100 loci associated with blood lipid levels, but much of the trait heritability remains unexplained, and at most loci the identities of the trait-influencing variants remain unknown. We conducted a trans-ethnic fine-mapping study at 18, 22, and 18 GWAS loci on the Metabochip for their association with triglycerides (TG, high-density lipoprotein cholesterol (HDL-C, and low-density lipoprotein cholesterol (LDL-C, respectively, in individuals of African American (n = 6,832, East Asian (n = 9,449, and European (n = 10,829 ancestry. We aimed to identify the variants with strongest association at each locus, identify additional and population-specific signals, refine association signals, and assess the relative significance of previously described functional variants. Among the 58 loci, 33 exhibited evidence of association at P<1 × 10(-4 in at least one ancestry group. Sequential conditional analyses revealed that ten, nine, and four loci in African Americans, Europeans, and East Asians, respectively, exhibited two or more signals. At these loci, accounting for all signals led to a 1.3- to 1.8-fold increase in the explained phenotypic variance compared to the strongest signals. Distinct signals across ancestry groups were identified at PCSK9 and APOA5. Trans-ethnic analyses narrowed the signals to smaller sets of variants at GCKR, PPP1R3B, ABO, LCAT, and ABCA1. Of 27 variants reported previously to have functional effects, 74% exhibited the strongest association at the respective signal. In conclusion, trans-ethnic high-density genotyping and analysis confirm the presence of allelic heterogeneity, allow the identification of population-specific variants, and limit the number of candidate SNPs for functional studies.

  17. Human rotavirus strains bearing VP4 gene P[6] allele recovered from asymptomatic or symptomatic infections share similar, if not identical, VP4 neutralization specificities

    International Nuclear Information System (INIS)

    Hoshino, Yasutaka; Jones, Ronald W.; Ross, Jerri; Santos, Norma; Kapikian, Albert Z.

    2003-01-01

    A rotavirus VP4 gene P[6] allele has been documented in a number of countries to be characteristically associated with an endemic predominantly asymptomatic infection in neonates in maternity hospital nurseries. The mechanisms underlying the endemicity and asymptomatic nature of such neonatal infections remain unknown. Rotavirus strains sharing this same P genotype, however, have more recently been recovered from an increasing number of symptomatic diarrheal episodes in infants and young children in various parts of the world. Previously, we have shown that an asymptomatic P[6] rotavirus neonatal infection is not associated with a unique VP7 (G) serotype but may occur in conjunction with various G types. Although amino acid sequence comparisons of the VP4 gene between selected 'asymptomatic' and 'symptomatic' P[6] rotavirus strains have been reported and yielded information concerning their VP4 genotypes, serotypic comparisons of the outer capsid spike protein VP4 of such viruses have not been studied systematically by two-way cross-neutralizations. We determined the VP4 neutralization specificities of four asymptomatic and four symptomatic P[6] strains: two each of asymptomatic and symptomatic strains by two-way tests, and two each of additional asymptomatic and symptomatic strains by one-way tests. Both asymptomatic and symptomatic P[6] strains were shown to bear similar, if not identical, VP4 neutralization specificities. Thus, P[6] rotavirus strains causing asymptomatic or symptomatic infections did not appear to belong to unique P (VP4) serotypes. In addition, a close VP4 serotypic relationship between human P[6] rotavirus strains and the porcine P[6] rotavirus Gottfried strain was confirmed

  18. Spatial organization of the budding yeast genome in the cell nucleus and identification of specific chromatin interactions from multi-chromosome constrained chromatin model.

    Science.gov (United States)

    Gürsoy, Gamze; Xu, Yun; Liang, Jie

    2017-07-01

    Nuclear landmarks and biochemical factors play important roles in the organization of the yeast genome. The interaction pattern of budding yeast as measured from genome-wide 3C studies are largely recapitulated by model polymer genomes subject to landmark constraints. However, the origin of inter-chromosomal interactions, specific roles of individual landmarks, and the roles of biochemical factors in yeast genome organization remain unclear. Here we describe a multi-chromosome constrained self-avoiding chromatin model (mC-SAC) to gain understanding of the budding yeast genome organization. With significantly improved sampling of genome structures, both intra- and inter-chromosomal interaction patterns from genome-wide 3C studies are accurately captured in our model at higher resolution than previous studies. We show that nuclear confinement is a key determinant of the intra-chromosomal interactions, and centromere tethering is responsible for the inter-chromosomal interactions. In addition, important genomic elements such as fragile sites and tRNA genes are found to be clustered spatially, largely due to centromere tethering. We uncovered previously unknown interactions that were not captured by genome-wide 3C studies, which are found to be enriched with tRNA genes, RNAPIII and TFIIS binding. Moreover, we identified specific high-frequency genome-wide 3C interactions that are unaccounted for by polymer effects under landmark constraints. These interactions are enriched with important genes and likely play biological roles.

  19. CARAT: A novel method for allelic detection of DNA copy number changes using high density oligonucleotide arrays

    Directory of Open Access Journals (Sweden)

    Ishikawa Shumpei

    2006-02-01

    Full Text Available Abstract Background DNA copy number alterations are one of the main characteristics of the cancer cell karyotype and can contribute to the complex phenotype of these cells. These alterations can lead to gains in cellular oncogenes as well as losses in tumor suppressor genes and can span small intervals as well as involve entire chromosomes. The ability to accurately detect these changes is central to understanding how they impact the biology of the cell. Results We describe a novel algorithm called CARAT (Copy Number Analysis with Regression And Tree that uses probe intensity information to infer copy number in an allele-specific manner from high density DNA oligonuceotide arrays designed to genotype over 100, 000 SNPs. Total and allele-specific copy number estimations using CARAT are independently evaluated for a subset of SNPs using quantitative PCR and allelic TaqMan reactions with several human breast cancer cell lines. The sensitivity and specificity of the algorithm are characterized using DNA samples containing differing numbers of X chromosomes as well as a test set of normal individuals. Results from the algorithm show a high degree of agreement with results from independent verification methods. Conclusion Overall, CARAT automatically detects regions with copy number variations and assigns a significance score to each alteration as well as generating allele-specific output. When coupled with SNP genotype calls from the same array, CARAT provides additional detail into the structure of genome wide alterations that can contribute to allelic imbalance.

  20. Female site-specific transposase-induced recombination: a high-efficiency method for fine mapping mutations on the X chromosome in Drosophila.

    OpenAIRE

    Marcus, Jeffrey M

    2003-01-01

    P-element transposons in the Drosophila germline mobilize only in the presence of the appropriate transposase enzyme. Sometimes, instead of mobilizing completely, P elements will undergo site-specific recombination with the homologous chromosome. Site-specific recombination is the basis for male recombination mapping, since the male germline does not normally undergo recombination. Site-specific recombination also takes place in females, but this has been difficult to study because of the obs...

  1. Human chromosome-specific changes in a human-hamster hybrid cell line (AL) assessed by fluorescent in situ hybridization (fish)

    International Nuclear Information System (INIS)

    Geard, Charles R.; Jenkins, Gloria

    1995-01-01

    Purpose: To quantitatively assess all gamma-ray induced chromosomal changes confined to one human chromosome using fluorescence microscopy and in situ hybridization with a fluorescently labeled human chromosome specific nucleic acid probe. Methods and Materials: Synchronized human-hamster hybrid cells containing human chromosome 11 were obtained by a modified mitotic shake-off procedure. G1 phase cells (> 95%) were irradiated with 137 Cs gamma rays (0, 0.5, 1.0, 1.5, 2.0, 4.0, 6.0, 8.0, and 10.0 Gy) at a dose rate of 1.1 Gy/min and mitotic cells collected 16-20 h later; chromosomal spreads were prepared, denatured, and hybridized with a fluorescein-tagged nucleic acid probe against total human DNA. Chromosomes were examined by fluorescence microscopy and all categories of change involving the human chromosome 11 as target, recorded. Results: Overall, of the 3104 human-hamster hybrid cells examined, 82.1% were euploid, of which 88.6% contained one copy of human chromosome 11, 6.2% contained two copies, and 5.2% contained 0 copies. This is compatible with mitotic nondisjunction in a small fraction of cells. Of the remaining 17.9% of cells, 85.2% were tetraploid cells with two copies of human chromosome 11. For all aberrations involving human chromosome 11 there was a linear relationship between yield and absorbed dose of 0.1 aberrations per chromosome per Gy. The yield of dicentrics, translocations, and terminal deletions that involve one lesion on the human chromosome was linear, while the yield of interstitial deletions that arise from two interacting lesions on the human chromosome was curvilinear. The frequencies of dicentrics and translocations were about equal, while there was a high (40-60%) incidence of incomplete exchanges between human and hamster chromosomes. Conclusions: Fluorescent in situ hybridization (FISH) procedures allow for the efficient detection of a broad range of induced changes in target chromosomes. Symmetrical exchanges induced in G1

  2. Site-specific deletions of chromosomally located DNA segments with the multimer resolution system of broad-host-range plasmid RP4

    DEFF Research Database (Denmark)

    Sternberg, Claus; Eberl, Leo; Sanchezromero, Juan M.

    1995-01-01

    The multimer resolution system (mrs) of the broad-host-range plasmid RP4 has been exploited to develop a general method that permits the precise excision of chromosomal segments in a variety of gram-negative bacteria. The procedure is based on the site-specific recombination between two directly ...

  3. Ten alien chromosome additions of Gossypium hirsutum-Gossypium bickii developed by integrative uses of GISH and species-specific SSR markers.

    Science.gov (United States)

    Tang, Dong; Feng, Shouli; Li, Sai; Chen, Yu; Zhou, Baoliang

    2018-03-27

    Gossypium bickii: (2n = 26, G 1 G 1 ), a wild diploid cotton, carries many favourable traits. However, these favourable traits cannot be directly transferred into G. hirsutum (2n = 52, AADD) cultivars due to the differences in genomes. Monosomic alien addition lines (MAALs) are considered an invaluable tool for the introgression of genes of interest from wild relatives into cultivated crops. In this study, the G. hirsutum-G. bickii amphidiploid (2n = 78, AADDG 1 G 1 ) was backcrossed with G. hirsutum to develop alien additions containing individual G. bickii chromosomes in a G. hirsutum background. Genomic in situ hybridization was employed to detect the number of alien chromosomes added to the backcross progenies. A total of 183 G. bickii-specific DNA markers were developed to discriminate the identities of the G. bickii chromosomes added to G. hirsutum and assess the alien chromosome transmissibility. Chromosomes 4G b and 13G b showed the highest transmissibility, while chromosomes 1G b , 7G b and 11G b showed the lowest. Ten of the 13 possible G. hirsutum-G. bickii MAALs were isolated and characterized, which will lay the foundation for transferring resistance genes of G. bickii into G. hirsutum, as well as for gene assignment, physical mapping, and selective isolation and mapping of cDNAs for particular G. bickii chromosomes. The strategies of how to use MAALs to develop varieties with the trait of interest from wild species (such as glanded plant-glandless seed) were proposed and discussed.

  4. Minority drug-resistant HIV-1 variants in treatment naïve East-African and Caucasian patients detected by allele-specific real-time PCR.

    Directory of Open Access Journals (Sweden)

    Halime Ekici

    Full Text Available To assess the presence of two major non-nucleoside reverse transcriptase inhibitors (NNRTI drug resistance mutations (DRMs, Y181C and K103N, in minor viral quasispecies of treatment naïve HIV-1 infected East-African and Swedish patients by allele-specific polymerase chain reaction (AS-PCR.Treatment naïve adults (n=191 with three epidemiological backgrounds were included: 92 Ethiopians living in Ethiopia; 55 East-Africans who had migrated to Sweden; and 44 Caucasians living in Sweden. The pol gene was analysed by standard population sequencing and by AS-PCR for the detection of Y181C and K103N.The Y181C was detected in the minority quasispecies of six Ethiopians (6.5%, in two Caucasians (4.5%, and in one East-African (1.8%. The K103N was detected in one East- African (1.8%, by both methods. The proportion of mutants ranged from 0.25% to 17.5%. Additional DRMs were found in all three treatment naïve patient groups by population sequencing.Major NNRTI mutations can be found by AS-PCR in minor quasispecies of treatment naïve HIV-1 infected Ethiopians living in Ethiopia, in East-African and Caucasian patients living in Sweden in whom population sequencing reveal wild-type virus only. Surveys with standard sequencing are likely to underestimate transmitted drug resistance and the presence of resistant minor quasispecies in treatment naïve patients should be topic for future large scale studies.

  5. Emergence of a Homo sapiens-specific gene family and chromosome 16p11.2 CNV susceptibility.

    Science.gov (United States)

    Nuttle, Xander; Giannuzzi, Giuliana; Duyzend, Michael H; Schraiber, Joshua G; Narvaiza, Iñigo; Sudmant, Peter H; Penn, Osnat; Chiatante, Giorgia; Malig, Maika; Huddleston, John; Benner, Chris; Camponeschi, Francesca; Ciofi-Baffoni, Simone; Stessman, Holly A F; Marchetto, Maria C N; Denman, Laura; Harshman, Lana; Baker, Carl; Raja, Archana; Penewit, Kelsi; Janke, Nicolette; Tang, W Joyce; Ventura, Mario; Banci, Lucia; Antonacci, Francesca; Akey, Joshua M; Amemiya, Chris T; Gage, Fred H; Reymond, Alexandre; Eichler, Evan E

    2016-08-11

    Genetic differences that specify unique aspects of human evolution have typically been identified by comparative analyses between the genomes of humans and closely related primates, including more recently the genomes of archaic hominins. Not all regions of the genome, however, are equally amenable to such study. Recurrent copy number variation (CNV) at chromosome 16p11.2 accounts for approximately 1% of cases of autism and is mediated by a complex set of segmental duplications, many of which arose recently during human evolution. Here we reconstruct the evolutionary history of the locus and identify bolA family member 2 (BOLA2) as a gene duplicated exclusively in Homo sapiens. We estimate that a 95-kilobase-pair segment containing BOLA2 duplicated across the critical region approximately 282 thousand years ago (ka), one of the latest among a series of genomic changes that dramatically restructured the locus during hominid evolution. All humans examined carried one or more copies of the duplication, which nearly fixed early in the human lineage--a pattern unlikely to have arisen so rapidly in the absence of selection (P sapiens-specific duplication. In summary, the duplicative transposition of BOLA2 at the root of the H. sapiens lineage about 282 ka simultaneously increased copy number of a gene associated with iron homeostasis and predisposed our species to recurrent rearrangements associated with disease.

  6. X- and Y-chromosome specific variants of the amelogenin gene allow sex determination in sheep (Ovis aries and European red deer (Cervus elaphus

    Directory of Open Access Journals (Sweden)

    Brenig B

    2005-03-01

    Full Text Available Abstract Background Simple and precise methods for sex determination in animals are a pre-requisite for a number of applications in animal production and forensics. However, some of the existing methods depend only on the detection of Y-chromosome specific sequences. Therefore, the abscence of a signal does not necessarily mean that the sample is of female origin, because experimental errors can also lead to negative results. Thus, the detection of Y- and X-chromosome specific sequences is advantageous. Results A novel method for sex identification in mammals (sheep, Ovis aries and European red deer, Cervus elaphus is described, using a polymerase chain reaction (PCR and sequencing of a part of the amelogenin gene. A partial sequence of the amelogenin gene of sheep and red deer was obtained, which exists on both X and Y chromosomes with a deletion region on the Y chromosome. With a specific pair of primers a DNA fragment of different length between the male and female mammal was amplified. Conclusion PCR amplification using the amelogenin gene primers is useful in sex identification of samples from sheep and red deer and can be applied to DNA analysis of micro samples with small amounts of DNA such as hair roots as well as bones or embryo biopsies.

  7. Site-specific antibodies distinguish single amino acid substitutions in position 57 in HLA-DQ beta-chain alleles associated with insulin-dependent diabetes

    DEFF Research Database (Denmark)

    Atar, D; Dyrberg, T; Michelsen, Birgitte

    1989-01-01

    The HLA-DQ beta-chain gene shows a close association with susceptibility or resistance to autoimmune insulin-dependent diabetes mellitus (IDDM) and it has been suggested that the amino acid in position 57 may be of pathogenetic importance. To study the expression of the IDDM associated HLA-DQ beta......-chain alleles, we immunized rabbits with 12 to 13 amino acid long peptides representing HLA-DQw7 and -DQw8 allelic sequences, differing only by one amino acid in position 57 being aspartic acid (Asp) and alanine (Ala), respectively. Immunoblot analysis of lymphoblastoid cells showed that several antisera...

  8. "European" race-specific metacentrics in East Siberian common shrews (Sorex araneus): a description of two new chromosomal races, Irkutsk and Zima.

    Science.gov (United States)

    Pavlova, Svetlana V; Borisov, Sergei A; Timoshenko, Alexander F; Sheftel, Boris I

    2017-01-01

    Karyotype studies of common shrews in the vicinity of Lake Baikal (Irkutsk Region, Eastern Siberia) resulted in the description of two new chromosomal races of Sorex araneus Linnaeus, 1758 (Lypotyphla, Mammalia), additional to 5 races formerly found in Siberia. In the karyotypes of 12 specimens from 3 locations, the polymorphism of metacentric and acrocentric chromosomes of the Robertsonian type was recorded and two distinct groups of karyotypes interpreted as the chromosomal races were revealed. They are geographically distant and described under the racial names Irkutsk (Ir) and Zima (Zi). Karyotypes of both races were characterized by species-specific (the same for all 74 races known so far) metacentric autosomes af, bc, tu and jl , and the typical sex chromosome system - XX/XY 1 Y 2 . The race-specific arm chromosome combinations include three metacentrics and four acrocentrics in the Irkutsk race ( gk, hi, nq, m, o, p, r ) and four metacentrics and two acrocentrics in the Zima race ( gm, hi, ko, nq, p, r ). Within the races, individuals with polymorphic chromosomes were detected ( g/m, k/o, n/q, p/r ). The presence of the specific metacentric gk allowed us to include the Irkutsk race into the Siberian Karyotypic Group (SKG), distributed in surrounding regions. The Zima race karyotype contained two metacentrics, gm and ko , which have been never found in the Siberian part of the species range, but appear as the common feature of chromosomal races belonging to the West European Karyotypic Group (WEKG). Moreover, the metacentrics of that karyotype are almost identical to the Åkarp race (except the heterozygous pair p/r ) locally found in the southern Sweden. One of two Siberian races described here for the first time, the Zima race, occurs in an area considerably distant from Europe and shares the common metacentrics ( gm, hi, ko ) with races included in WEKG. This fact may support a hypothesis of independent formation of identical arm chromosome combinations

  9. CTCF-mediated transcriptional regulation through cell type-specific chromosome organization in the β-globin locus

    OpenAIRE

    Junier, Ivan; Dale, Ryan K.; Hou, Chunhui; Képès, François; Dean, Ann

    2012-01-01

    International audience; The principles underlying the architectural landscape of chromatin beyond the nucleosome level in living cells remains largely unknown despite its potential to play a role in mammalian gene regulation. We investigated the three-dimensional folding of a 1 Mbp region of human chromosome 11 containing the β-globin genes by integrating looping interactions of the CCCTC-binding insulator protein CTCF determined comprehensively by chromosome conformation capture (3C) into a ...

  10. Establishment of real time allele specific locked nucleic acid quantitative PCR for detection of HBV YIDD (ATT mutation and evaluation of its application.

    Directory of Open Access Journals (Sweden)

    Yongbin Zeng

    Full Text Available BACKGROUND: Long-term use of nucleos(tide analogues can increase risk of HBV drug-resistance mutations. The rtM204I (ATT coding for isoleucine is one of the most important resistance mutation sites. Establishing a simple, rapid, reliable and highly sensitive assay to detect the resistant mutants as early as possible is of great clinical significance. METHODS: Recombinant plasmids for HBV YMDD (tyrosine-methionine-aspartate-aspartate and YIDD (tyrosine-isoleucine-aspartate-aspartate were constructed by TA cloning. Real time allele specific locked nucleic acid quantitative PCR (RT-AS-LNA-qPCR with SYBR Green I was established by LNA-modified primers and evaluated with standard recombinant plasmids, clinical templates (the clinical wild type and mutant HBV DNA mixture and 102 serum samples from nucleos(tide analogues-experienced patients. The serum samples from a chronic hepatitis B (CHB patient firstly received LMV mono therapy and then switched to LMV + ADV combined therapy were also dynamically analyzed for 10 times. RESULTS: The linear range of the assay was between 1×10(9 copies/μl and 1 × 10(2 copies/μl. The low detection limit was 1 × 10(1 copies/μl. Sensitivity of the assay were 10(-6, 10(-4 and 10(-2 in the wild-type background of 1 × 10(9 copies/μl, 1 × 10(7 copies/μl and 1 × 10(5 copies/μl, respectively. The sensitivity of the assay in detection of clinical samples was 0.03%. The complete coincidence rate between RT-AS-LNA-qPCR and direct sequencing was 91.2% (93/102, partial coincidence rate was 8.8% (9/102, and no complete discordance was observed. The two assays showed a high concordance (Kappa = 0.676, P = 0.000. Minor variants can be detected 18 weeks earlier than the rebound of HBV DNA load and alanine aminotransferase level. CONCLUSIONS: A rapid, cost-effective, high sensitive, specific and reliable method of RT-AS-LNA-qPCR with SYBR Green I for early and absolute quantification of HBV YIDD (ATT coding for isoleucine

  11. Stage-specific damage to synaptonemal complexes and metaphase chromosomes induced by X rays in male mouse germ cells

    International Nuclear Information System (INIS)

    Backer, L.C.; Sontag, M.R.; Allen, J.W.

    1991-01-01

    Synaptonemal complexes (SCs) reveal mutagen-induced effects in germ cell meiotic chromosomes. The study was aimed at characterizing relationships between SC and metaphase I chromosome damage following radiation exposure at various stages of spermatogenesis. Male mice were irradiated with doses of 0, 2, or 4 Gy, and spermatocytes were harvested at times consistent with earlier exposures as spermatogonial stem cells, preleptotene cells (premeiotic DNA synthesis), or meiotic prophase cells. After stem-cell exposure, twice as many rearrangements were observed in SCs as in metaphase I chromosomes. Irradiation during premeiotic DNA synthesis resulted in dose-related increases in SC breakage and rearrangements (including novel forms) and in metaphase chromosomal aberrations. Following prophase exposure, various types and levels of SC and metaphase damage were observed. Irradiation of zygotene cells led to high frequencies of chromosome multivalents in metaphase I without a correspondingly high level of damage in preceding prophase SCs. Thus, irradiation of premeiotic and meiotic cells results in variable relationships between SC and metaphase chromosome damage

  12. A Gene Catalogue of the Euchromatic Male-Specific Region of the Horse Y Chromosome: Comparison with Human and Other Mammals

    OpenAIRE

    Paria, Nandina; Raudsepp, Terje; Pearks Wilkerson, Alison J.; O'Brien, Patricia C. M.; Ferguson-Smith, Malcom A.; Love, Charles C.; Arnold, Carolyn; Rakestraw, Peter; Murphy, William J.; Chowdhary, Bhanu P.

    2011-01-01

    Studies of the Y chromosome in primates, rodents and carnivores provide compelling evidence that the male specific region of Y (MSY) contains functional genes, many of which have specialized roles in spermatogenesis and male-fertility. Little similarity, however, has been found between the gene content and sequence of MSY in different species. This hinders the discovery of species-specific male fertility genes and limits our understanding about MSY evolution in mammals. Here, a detailed MSY g...

  13. V-src oncogene-specific carboxy-terminal peptide is immunoprotective against Rous sarcoma growth in chickens with MHC class I allele B-F12

    Czech Academy of Sciences Publication Activity Database

    Hofmann, A.; Plachý, Jiří; Hunt, L.; Kaufman, J.; Hála, K.

    2003-01-01

    Roč. 2003, č. 21 (2003), s. 4694-4699 ISSN 0264-410X Institutional research plan: CEZ:AV0Z5052915 Keywords : Rous sarcoma * v-src peptide * chicken MHC class I allele Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.007, year: 2003

  14. A Sensitive and Specific Diagnostic Panel to Distinguish Diffuse Astrocytoma from Astrocytosis: Chromosome 7 Gain with Mutant Isocitrate Dehydrogenase 1 and p53

    Science.gov (United States)

    Camelo-Piragua, Sandra; Jansen, Michael; Ganguly, Aniruddha; Kim, J. ChulMin; Cosper, Arjola K.; Dias-Santagata, Dora; Nutt, Catherine L.; Iafrate, A. John; Louis, David N.

    2011-01-01

    One of the major challenges of surgical neuropathology is the distinction of diffuse astrocytoma (World Health Organization [WHO] grade II) from astrocytosis. The most commonly used ancillary tool to solve this problem is p53 immunohistochemistry (IHC), but this is neither sensitive nor specific. Isocitrate dehydrogenase 1 (IDH1) mutations are common in lower grade gliomas, with most causing a specific amino acid change (R132H) that can be detected with a monoclonal antibody. IDH2 mutations are rare, but also occur in gliomas. In addition, gains of chromosome 7 are common in gliomas. In this study we assessed the status of p53, IDH1/2 and chromosome 7 to determine the most useful panel to distinguish astrocytoma from astrocytosis. We studied biopsy specimens from 21 WHO grade II diffuse astrocytomas and 20 reactive conditions. The single most sensitive test to identify astrocytoma is fluorescence in situ hybridization (FISH) for chromosome 7 gain (76.2%). The combination of p53 and mutant IDH1 IHC provides a higher sensitivity (71.4%) than either test alone (47.8%); this combination offers a practical initial approach for the surgical pathologist. The best overall sensitivity (95%) is achieved when FISH for chromosome 7 gain is added to the p53-mutant IDH1 IHC panel. PMID:21343879

  15. Towards a molecular taxonomic key of the Aurantioideae subfamily using chloroplastic SNP diagnostic markers of the main clades genotyped by competitive allele-specific PCR.

    Science.gov (United States)

    Oueslati, Amel; Ollitrault, Frederique; Baraket, Ghada; Salhi-Hannachi, Amel; Navarro, Luis; Ollitrault, Patrick

    2016-08-18

    Chloroplast DNA is a primary source of molecular variations for phylogenetic analysis of photosynthetic eukaryotes. However, the sequencing and analysis of multiple chloroplastic regions is difficult to apply to large collections or large samples of natural populations. The objective of our work was to demonstrate that a molecular taxonomic key based on easy, scalable and low-cost genotyping method should be developed from a set of Single Nucleotide Polymorphisms (SNPs) diagnostic of well-established clades. It was applied to the Aurantioideae subfamily, the largest group of the Rutaceae family that includes the cultivated citrus species. The publicly available nucleotide sequences of eight plastid genomic regions were compared for 79 accessions of the Aurantioideae subfamily to search for SNPs revealing taxonomic differentiation at the inter-tribe, inter-subtribe, inter-genus and interspecific levels. Diagnostic SNPs (DSNPs) were found for 46 of the 54 clade levels analysed. Forty DSNPs were selected to develop KASPar markers and their taxonomic value was tested by genotyping 108 accessions of the Aurantioideae subfamily. Twenty-seven markers diagnostic of 24 clades were validated and they displayed a very high rate of transferability in the Aurantioideae subfamily (only 1.2 % of missing data on average). The UPGMA from the validated markers produced a cladistic organisation that was highly coherent with the previous phylogenetic analysis based on the sequence data of the eight plasmid regions. In particular, the monophyletic origin of the "true citrus" genera plus Oxanthera was validated. However, some clarification remains necessary regarding the organisation of the other wild species of the Citreae tribe. We validated the concept that with well-established clades, DSNPs can be selected and efficiently transformed into competitive allele-specific PCR markers (KASPar method) allowing cost-effective highly efficient cladistic analysis in large collections at

  16. Fetal sex determination in the first trimester of pregnancy using a Y chromosome-specific DNA probe

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Y.; Huang, S.; Chen, M.; Huang, Y.; Zhang, M.; Dong, J.; Ku, A.; Xu, S.

    1987-05-01

    Prenatal determination of fetal sex is important for the prevention of X-linked disorders such as hemophilia, Lesch-Nyhan syndrome and Duchenne muscular dystrophy. The complex procedures of prenatal diagnosis for X-linked disorders are unnecessary if the fetus is female, because usually no clinical symptoms ever appear in female. pY 3.4 probe used in this work for sex determination is a 3.4 kilobase human repeat sequence. The probe is specific for the Y chromosome of males and can be used for sex determination. The other prove pBLUR used in this paper as control is a widely dispersed, highly repeated human Alu family DNA sequence, represented equally in male and female DNA. On the basis of the relative densities of the autoradiographic spots produced by hybridization of fetal DNA with pY3.4 and pBLUR, the sex of fetus can be clearly identified. Further the authors can determine the radioactive intensity (cpm) of the hybridized DNA spots and the ratio of hybridization with Y3.4 to pBLUR (Y3.4/pBLUR x 10). Results show that the hybridization ratio of DNA from chorionic villi of male (1.03 +/- 0.24) is significantly higher than that of female (0.16 +/- 0.09). Therefore, sex determination of the fetus can be made, based on the ratio of pY3.4/pBLUR x 10. If necessary they can also use Southern hybridization with pY 3.4 probe of DNA isolated from chorionic villi to confirm the result of dot hybridization.

  17. The genetic content of chromosomal inversions across a wide latitudinal gradient.

    Directory of Open Access Journals (Sweden)

    Pedro Simões

    Full Text Available There is increasing evidence regarding the role of chromosomal inversions in relevant biological processes such as local adaptation and speciation. A classic example of the adaptive role of chromosomal polymorphisms is given by the clines of inversion frequencies in Drosophila subobscura, repeatable across continents. Nevertheless, not much is known about the molecular variation associated with these polymorphisms. We characterized the genetic content of ca. 600 individuals from nine European populations following a latitudinal gradient by analysing 19 microsatellite loci from two autosomes (J and U and the sex chromosome (A, taking into account their chromosomal inversions. Our results clearly demonstrate the molecular genetic uniformity within a given chromosomal inversion across a large latitudinal gradient, particularly from Groningen (Netherlands in the north to Málaga (Spain in the south, experiencing highly diverse environmental conditions. This low genetic differentiation within the same gene arrangement across the nine European populations is consistent with the local adaptation hypothesis for th evolutionof chromosomal polymorphisms. We also show the effective role of chromosomal inversions in maintaining different genetic pools within these inverted genomic regions even in the presence of high gene flow. Inversions represent thus an important barrier to gene flux and can help maintain specific allelic combinations with positive effects on fitness. Consistent patterns of microsatellite allele-inversion linkage disequilibrium particularly in loci within inversions were also observed. Finally, we identified areas within inversions presenting clinal variation that might be under selection.

  18. Three loci on mouse chromosome 5 and 10 modulate sex determination in XX Ods/+ mice.

    Science.gov (United States)

    Poirier, Christophe; Moran, Jennifer L; Kovanci, Ertug; Petit, Deborah C; Beier, David R; Bishop, Colin E

    2007-07-01

    In mouse, XY embryos are committed to the male sex determination pathway after the transient expression of the Y-linked Sry gene in the Sertoli cell lineage between 10.5 and 12.5 dpc. In the C57BL/6J strain, male sex determination program can be modulated by some autosomal genes. The C57BL/6J alleles at these autosomal loci can antagonize male sex determination in combination with specific Sry alleles. In this report, the authors have identified an effect of these C57BL/6J specific alleles in combination with a mutated Sox9 allele, Sox9(Ods). Authors report the mapping of three of these genetic loci on mouse chromosome 5 and 10 in a backcross of the Ods mutation to the C57BL/6J background. Our study confirms the importance of the strain C57BL/6J for the investigation of the genetic mechanisms that control sex determination.

  19. Dahl (S x R congenic strain analysis confirms and defines a chromosome 5 female-specific blood pressure quantitative trait locus to <7 Mbp.

    Directory of Open Access Journals (Sweden)

    Victoria L M Herrera

    Full Text Available The detection of multiple sex-specific blood pressure (BP quantitative trait loci (QTLs in independent total genome analyses of F2 (Dahl S x R-intercross male and female rat cohorts confirms clinical observations of sex-specific disease cause and response to treatment among hypertensive patients, and mandate the identification of sex-specific hypertension genes/mechanisms. We developed and studied two congenic strains, S.R5A and S.R5B introgressing Dahl R-chromosome 5 segments into Dahl S chromosome 5 region spanning putative BP-f1 and BP-f2 QTLs. Radiotelemetric non-stressed 24-hour BP analysis at four weeks post-high salt diet (8% NaCl challenge, identified only S.R5B congenic rats with lower SBP (-26.5 mmHg, P = 0.002, DBP (-23.7 mmHg, P = 0.004 and MAP (-25.1 mmHg, P = 0.002 compared with Dahl S female controls at four months of age confirming BP-f1 but not BP-f2 QTL on rat chromosome 5. The S.R5B congenic segment did not affect pulse pressure and relative heart weight indicating that the gene underlying BP-f1 does not influence arterial stiffness and cardiac hypertrophy. The results of our congenic analysis narrowed BP-f1 to chromosome 5 coordinates 134.9-141.5 Mbp setting up the basis for further fine mapping of BP-f1 and eventual identification of the specific gene variant accounting for BP-f1 effect on blood pressure.

  20. Dahl (S x R) congenic strain analysis confirms and defines a chromosome 5 female-specific blood pressure quantitative trait locus to <7 Mbp.

    Science.gov (United States)

    Herrera, Victoria L M; Pasion, Khristine A; Moran, Ann Marie; Ruiz-Opazo, Nelson

    2012-01-01

    The detection of multiple sex-specific blood pressure (BP) quantitative trait loci (QTLs) in independent total genome analyses of F2 (Dahl S x R)-intercross male and female rat cohorts confirms clinical observations of sex-specific disease cause and response to treatment among hypertensive patients, and mandate the identification of sex-specific hypertension genes/mechanisms. We developed and studied two congenic strains, S.R5A and S.R5B introgressing Dahl R-chromosome 5 segments into Dahl S chromosome 5 region spanning putative BP-f1 and BP-f2 QTLs. Radiotelemetric non-stressed 24-hour BP analysis at four weeks post-high salt diet (8% NaCl) challenge, identified only S.R5B congenic rats with lower SBP (-26.5 mmHg, P = 0.002), DBP (-23.7 mmHg, P = 0.004) and MAP (-25.1 mmHg, P = 0.002) compared with Dahl S female controls at four months of age confirming BP-f1 but not BP-f2 QTL on rat chromosome 5. The S.R5B congenic segment did not affect pulse pressure and relative heart weight indicating that the gene underlying BP-f1 does not influence arterial stiffness and cardiac hypertrophy. The results of our congenic analysis narrowed BP-f1 to chromosome 5 coordinates 134.9-141.5 Mbp setting up the basis for further fine mapping of BP-f1 and eventual identification of the specific gene variant accounting for BP-f1 effect on blood pressure.

  1. A gene catalogue of the euchromatic male-specific region of the horse Y chromosome: comparison with human and other mammals.

    Directory of Open Access Journals (Sweden)

    Nandina Paria

    Full Text Available Studies of the Y chromosome in primates, rodents and carnivores provide compelling evidence that the male specific region of Y (MSY contains functional genes, many of which have specialized roles in spermatogenesis and male-fertility. Little similarity, however, has been found between the gene content and sequence of MSY in different species. This hinders the discovery of species-specific male fertility genes and limits our understanding about MSY evolution in mammals. Here, a detailed MSY gene catalogue was developed for the horse--an odd-toed ungulate. Using direct cDNA selection from horse testis, and sequence analysis of Y-specific BAC clones, 37 horse MSY genes/transcripts were identified. The genes were mapped to the MSY BAC contig map, characterized for copy number, analyzed for transcriptional profiles by RT-PCR, examined for the presence of ORFs, and compared to other mammalian orthologs. We demonstrate that the horse MSY harbors 20 X-degenerate genes with known orthologs in other eutherian species. The remaining 17 genes are acquired or novel and have so far been identified only in the horse or donkey Y chromosomes. Notably, 3 transcripts were found in the heterochromatic part of the Y. We show that despite substantial differences between the sequence, gene content and organization of horse and other mammalian Y chromosomes, the functions of MSY genes are predominantly related to testis and spermatogenesis. Altogether, 10 multicopy genes with testis-specific expression were identified in the horse MSY, and considered likely candidate genes for stallion fertility. The findings establish an important foundation for the study of Y-linked genetic factors governing fertility in stallions, and improve our knowledge about the evolutionary processes that have shaped Y chromosomes in different mammalian lineages.

  2. A gene catalogue of the euchromatic male-specific region of the horse Y chromosome: comparison with human and other mammals.

    Science.gov (United States)

    Paria, Nandina; Raudsepp, Terje; Pearks Wilkerson, Alison J; O'Brien, Patricia C M; Ferguson-Smith, Malcom A; Love, Charles C; Arnold, Carolyn; Rakestraw, Peter; Murphy, William J; Chowdhary, Bhanu P

    2011-01-01

    Studies of the Y chromosome in primates, rodents and carnivores provide compelling evidence that the male specific region of Y (MSY) contains functional genes, many of which have specialized roles in spermatogenesis and male-fertility. Little similarity, however, has been found between the gene content and sequence of MSY in different species. This hinders the discovery of species-specific male fertility genes and limits our understanding about MSY evolution in mammals. Here, a detailed MSY gene catalogue was developed for the horse--an odd-toed ungulate. Using direct cDNA selection from horse testis, and sequence analysis of Y-specific BAC clones, 37 horse MSY genes/transcripts were identified. The genes were mapped to the MSY BAC contig map, characterized for copy number, analyzed for transcriptional profiles by RT-PCR, examined for the presence of ORFs, and compared to other mammalian orthologs. We demonstrate that the horse MSY harbors 20 X-degenerate genes with known orthologs in other eutherian species. The remaining 17 genes are acquired or novel and have so far been identified only in the horse or donkey Y chromosomes. Notably, 3 transcripts were found in the heterochromatic part of the Y. We show that despite substantial differences between the sequence, gene content and organization of horse and other mammalian Y chromosomes, the functions of MSY genes are predominantly related to testis and spermatogenesis. Altogether, 10 multicopy genes with testis-specific expression were identified in the horse MSY, and considered likely candidate genes for stallion fertility. The findings establish an important foundation for the study of Y-linked genetic factors governing fertility in stallions, and improve our knowledge about the evolutionary processes that have shaped Y chromosomes in different mammalian lineages.

  3. Characterization of new allele influencing flowering time in bread wheat introgressed from Triticum militinae.

    Science.gov (United States)

    Ivaničová, Zuzana; Jakobson, Irena; Reis, Diana; Šafář, Jan; Milec, Zbyněk; Abrouk, Michael; Doležel, Jaroslav; Järve, Kadri; Valárik, Miroslav

    2016-09-25

    Flowering time variation was identified within a mapping population of doubled haploid lines developed from a cross between the introgressive line 8.1 and spring bread wheat cv. Tähti. The line 8.1 carried introgressions from tetraploid Triticum militinae in the cv. Tähti genetic background on chromosomes 1A, 2A, 4A, 5A, 7A, 1B and 5B. The most significant QTL for the flowering time variation was identified within the introgressed region on chromosome 5A and its largest effect was associated with the VRN-A1 locus, accounting for up to 70% of phenotypic variance. The allele of T. militinae origin was designated as VRN-A1f-like. The effect of the VRN-A1f-like allele was verified in two other mapping populations. QTL analysis identified that in cv. Tähti and cv. Mooni genetic background, VRN-A1f-like allele incurred a delay of 1.9-18.6 days in flowering time, depending on growing conditions. Sequence comparison of the VRN-A1f-like and VRN-A1a alleles from the parental lines of the mapping populations revealed major mutations in the promoter region as well as in the first intron, including insertion of a MITE element and a large deletion. The sequence variation allowed construction of specific diagnostic PCR markers for VRN-A1f-like allele determination. Identification and quantification of the effect of the VRN-A1f-like allele offers a useful tool for wheat breeding and for studying fine-scale regulation of flowering pathways in wheat. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. The landscape of chromosomal aberrations in breast cancer mouse models reveals driver-specific routes to tumorigenesis

    NARCIS (Netherlands)

    Ben-David, Uri; Ha, Gavin; Khadka, Prasidda; Jin, Xin; Wong, Bang; Franke, Lude; Golub, Todd R.

    Aneuploidy and copy-number alterations (CNAs) are a hallmark of human cancer. Although genetically engineered mouse models (GEMMs) are commonly used to model human cancer, their chromosomal landscapes remain underexplored. Here we use gene expression profiles to infer CNAs in 3,108 samples from 45

  5. Stage specificity and dose-response relationships for chromosome aberrations induced in mouse primary spermatocytes following X-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Y.; Tobari, I.; Utsugi, T.

    1986-05-01

    In this study, dose-response relationships were examined for chromosome aberrations observed at diakinesis-metaphase I of spermatocytes with X-irradiation at various stages of meiosis (diplotene, mid-pachytene, zygotene and leptotene). The frequencies of cells with X-ray-induced chromosome aberrations increased with dose at all stages in the applied range of 0.5-3.0 Gy and tended to increase as the irradiated stages descended after leptotene stage. In three stages, the frequencies increased exponentially with dose, but the rates of induction of chromosome breaks were markedly different depending on the stages at which spermatocytes were irradiated with X-rays. The rate of induction was the highest at diplotene and the lowest at leptotene, suggesting that diplotene spermatocytes had the highest radiosensitivity to the induction of chromosome breaks, followed by pachytene, zygotene and leptotene spermatocytes in that order. The dose-response relationships fitted well to linear equations for deletion-type aberrations at each stage, and to linear-quadratic equations for exchange-type aberrations at all stages except for leptotene. At leptotene, the chromatid exchanges were hardly observed, the aberrations being mainly consisted of iso-chromatid fragments. On the contrary, chromatid exchanges and iso-chromatide deletions were mainly observed at later stages (zygotene-diplotene).

  6. Chromosomal rearrangements and gene flow over time in an inter-specific hybrid zone of the Sorex araneus group.

    Science.gov (United States)

    Yannic, G; Basset, P; Hausser, J

    2009-06-01

    Most hybrid zones have existed for hundreds or thousands of years but have generally been observed for only a short time period. Studies extending over periods long enough to track evolutionary changes in the zones or assess the ultimate outcome of hybridization are scarce. Here, we describe the evolution over time of the level of genetic isolation between two karyotypically different species of shrews (Sorex araneus and Sorex antinorii) at a hybrid zone located in the Swiss Alps. We first evaluated hybrid zone movement by contrasting patterns of gene flow and changes in cline parameters (centre and width) using 24 microsatellite loci, between two periods separated by 10 years apart. Additionally, we tested the role of chromosomal rearrangements on gene flow by analysing microsatellite loci located on both rearranged and common chromosomes to both species. We did not detect any movement of the hybrid zone during the period analysed, suggesting that the zone is a typical tension zone. However, the gene flow was significantly lower among the rearranged than the common chromosomes for the second period, whereas the difference was only marginally significant for the first period. This further supports the role of chromosomal rearrangements on gene flow between these taxa.

  7. Sex Chromosome Evolution, Heterochiasmy, and Physiological QTL in the Salmonid Brook Charr Salvelinus fontinalis

    Directory of Open Access Journals (Sweden)

    Ben J.G. Sutherland

    2017-08-01

    Full Text Available Whole-genome duplication (WGD can have large impacts on genome evolution, and much remains unknown about these impacts. This includes the mechanisms of coping with a duplicated sex determination system and whether this has an impact on increasing the diversity of sex determination mechanisms. Other impacts include sexual conflict, where alleles having different optimums in each sex can result in sequestration of genes into nonrecombining sex chromosomes. Sex chromosome development itself may involve sex-specific recombination rate (i.e., heterochiasmy, which is also poorly understood. The family Salmonidae is a model system for these phenomena, having undergone autotetraploidization and subsequent rediploidization in most of the genome at the base of the lineage. The salmonid master sex determining gene is known, and many species have nonhomologous sex chromosomes, putatively due to transposition of this gene. In this study, we identify the sex chromosome of Brook Charr Salvelinus fontinalis and compare sex chromosome identities across the lineage (eight species and four genera. Although nonhomology is frequent, homologous sex chromosomes and other consistencies are present in distantly related species, indicating probable convergence on specific sex and neo-sex chromosomes. We also characterize strong heterochiasmy with 2.7-fold more crossovers in maternal than paternal haplotypes with paternal crossovers biased to chromosome ends. When considering only rediploidized chromosomes, the overall heterochiasmy trend remains, although with only 1.9-fold more recombination in the female than the male. Y chromosome crossovers are restricted to a single end of the chromosome, and this chromosome contains a large interspecific inversion, although its status between males and females remains unknown. Finally, we identify quantitative trait loci (QTL for 21 unique growth, reproductive, and stress-related phenotypes to improve knowledge of the genetic

  8. Comparison of allele-specific PCR, created restriction-site PCR, and PCR with primer-introduced restriction analysis methods used for screening complex vertebral malformation carriers in Holstein cattle

    Science.gov (United States)

    Altınel, Ahmet

    2017-01-01

    Complex vertebral malformation (CVM) is an inherited, autosomal recessive disorder of Holstein cattle. The aim of this study was to compare sensitivity, specificity, positive and negative predictive values, accuracy, and rapidity of allele-specific polymerase chain reaction (AS-PCR), created restriction-site PCR (CRS-PCR), and PCR with primer-introduced restriction analysis (PCR-PIRA), three methods used in identification of CVM carriers in a Holstein cattle population. In order to screen for the G>T mutation in the solute carrier family 35 member A3 (SLC35A3) gene, DNA sequencing as the gold standard method was used. The prevalence of carriers and the mutant allele frequency were 3.2% and 0.016, respectively, among Holstein cattle in the Thrace region of Turkey. Among the three methods, the fastest but least accurate was AS-PCR. Although the rapidity of CRS-PCR and PCR-PIRA were nearly equal, the accuracy of PCR-PIRA was higher than that of CRS-PCR. Therefore, among the three methods, PCR-PIRA appears to be the most efficacious for screening of mutant alleles when identifying CVM carriers in a Holstein cattle population. PMID:28927256

  9. Attention deficit/hyperactivity disorder children with a 7-repeat allele of the dopamine recepter D4 gene have extreme behavior but normal performance on critical neuropsychological tests of attention

    NARCIS (Netherlands)

    Swanson, J.; Oosterlaan, J.; Murias, M.; Schuck, S.; Flodman, P.; Spence, M.A.; Wasdell, M.; Ding, Y.; Chi, H-C.; Smith, M.; Mann, M.; Carlson, C.; Kennedy, J.L.; Sergeant, J.A.; Leung, P.; Zhang, Y-P.; Sadeh, A.; Chan, C.; Whalen, C.K.; Babb, K.; Moyzis, R.; Posner, M.I.

    2000-01-01

    An association of the dopamine receptor D4 (DRD4) gene located on chromosome 11p15.5 and attention deficit/hyperactivity disorder (ADHD) has been demonstrated and replicated by multiple investigators. A specific allele [the 7-repeat of a 48-bp variable number of tandem repeats (VNTR) in exon 3] has

  10. Phosphorus Partitioning of Soybean Lines Containing Different Mutant Alleles of Two Soybean Seed-Specific Adenosine Triphosphate-Binding Cassette Phytic Acid Transporter Paralogs

    Directory of Open Access Journals (Sweden)

    Jason D. Gillman

    2013-03-01

    Full Text Available Seed phytate is a repository of P and minerals in soybean [ (L. Merr.] seeds that limits P and mineral bioavailability for monogastric animals (e.g., humans, swine [], and poultry [especially chicken, ] due to insufficient digestive tract phytase activity. We previously identified epistatic recessive mutations affecting two paralogous adenosine triphosphate-binding cassette phytic acid transporter genes (one a nonsense mutation in and the other a missense mutation in as the molecular genetic basis in the ethyl methanesulfonate (EMS-induced mutant low phytate soybean line M153. An additional mutant low phytate line, M766, contained one single nucleotide polymorphism within the ninth intron of the locus as well as a nonsense mutation in . The objectives of this research were to clarify the genetics underlying the low phytate phenotype in line M766 and to determine P partitioning in new combinations of mutant alleles from M766 and M153. Inheritance of nonsense alleles affecting both ( genes (one from M153 and one from M766 led to the production of viable seeds that contained transgressive reductions in total seed phytate and significantly higher levels of inorganic phosphate than has been reported for nontransgenic soybean material and will allow efficient molecular selection of soybeans with even greater reductions of phytate for improved quality soybean meal.

  11. Lipoprotein(a) and HIV: Allele-Specific Apolipoprotein(a) Levels Predict Carotid Intima-Media Thickness in HIV-Infected Young Women in the Women's Interagency HIV Study.

    Science.gov (United States)

    Enkhmaa, Byambaa; Anuurad, Erdembileg; Zhang, Wei; Li, Chin-Shang; Kaplan, Robert; Lazar, Jason; Merenstein, Dan; Karim, Roksana; Aouizerat, Brad; Cohen, Mardge; Butler, Kenneth; Pahwa, Savita; Ofotokun, Igho; Adimora, Adaora A; Golub, Elizabeth; Berglund, Lars

    2017-05-01

    In the general population, lipoprotein(a) [Lp(a)] has been established as an independent causal risk factor for cardiovascular disease. Lp(a) levels are to a major extent regulated by a size polymorphism in the apolipoprotein(a) [apo(a)] gene. The roles of Lp(a)/apo(a) in human immunodeficiency virus (HIV)-related elevated cardiovascular disease risk remain unclear. The associations between total plasma Lp(a) level, allele-specific apo(a) level, an Lp(a) level carried by individual apo(a) alleles, and common carotid artery intima-media thickness were assessed in 150 HIV-infected and 100 HIV-uninfected women in the WIHS (Women's Interagency HIV Study). Linear regression analyses with and without adjustments were used. The cohort was young (mean age, ≈31 years), with the majority being Blacks (≈70%). The prevalence of a small size apo(a) (≤22 Kringle repeats) or a high Lp(a) level (≥30 mg/dL) was similar by HIV status. Total plasma Lp(a) level ( P =0.029) and allele-specific apo(a) level carried by the smaller apo(a) sizes ( P =0.022) were significantly associated with carotid artery intima-media thickness in the HIV-infected women only. After accounting for confounders (age, race, smoking, body mass index, blood pressure, hepatitis C virus coinfection, menopause, plasma lipids, treatment status, CD4 + T cell count, and HIV/RNA viral load), the association remained significant for both Lp(a) ( P =0.035) and allele-specific apo(a) level carried by the smaller apo(a) sizes ( P =0.010) in the HIV-infected women. Notably, none of the other lipids/lipoproteins was associated with carotid artery intima-media thickness. Lp(a) and allele-specific apo(a) levels predict carotid artery intima-media thickness in HIV-infected young women. Further research is needed to identify underlying mechanisms of an increased Lp(a) atherogenicity in HIV infection. © 2017 American Heart Association, Inc.

  12. Generating resources for genomics of wheat homoeologous chromosome group 3: 3AS- and 3DS-specific BAC libraries

    Czech Academy of Sciences Publication Activity Database

    Šafář, Jan; Šimková, Hana; Kubaláková, Marie; Suchánková, Pavla; Čihalíková, Jarmila; Bartoš, Jan; Fiocchetti, F.; Roselli, M.; Gill, B. S.; Doležel, Jaroslav; Lucretti, S.

    2009-01-01

    Roč. 61, 1-2 (2009), s. 151-160 ISSN 0394-9257 R&D Projects: GA ČR GD521/05/H013; GA ČR GA521/06/1723; GA ČR GA521/07/1573; GA MŠk(CZ) LC06004; GA MŠk OC08025 Institutional research plan: CEZ:AV0Z50380511 Keywords : BAC library * Flow sorting * Homoeologous chromosomes Subject RIV: GE - Plant Breeding

  13. Advanced resources for plant genomics: BAC library specific for the short arm of wheat chromosome 1B

    Czech Academy of Sciences Publication Activity Database

    Janda, Jaroslav; Šafář, Jan; Kubaláková, Marie; Bartoš, Jan; Kovářová, Pavlína; Suchánková, Pavla; Pateyron, S.; Čihalíková, Jarmila; Sourdille, P.; Šimková, Hana; Faivre-Rampant, P.; Hřibová, Eva; Bernard, M.; Lukaszewski, A.; Doležel, Jaroslav; Chalhoub, B.

    2006-01-01

    Roč. 47, - (2006), s. 977-986 ISSN 0960-7412 R&D Projects: GA ČR GA521/04/0607; GA ČR GP521/05/P257; GA ČR GD521/05/H013; GA MŠk LC06004 Institutional research plan: CEZ:AV0Z50380511 Keywords : wheat * genomics * chromosome sorting Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 6.565, year: 2006

  14. 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.

  15. Isolation of probes specific to human chromosomal region 6p21 from immunoselected irradiation-fusion gene transfer hybrids

    International Nuclear Information System (INIS)

    Ragoussis, J.; Jones, T.A.; Sheer, D.; Shrimpton, A.E.; Goodfellow, P.N.; Trowsdale, J.; Ziegler, A.

    1991-01-01

    A hybrid cell line (R21/B1) containing a truncated human chromosome 6 (6pter-6q21) and a human Y chromosome on a hamster background was irradiated and fused to A23 (TK-) or W3GH (HPRT-) hamster cells. Clones containing expressed HLA class I genes (4/40) were selected using monoclonal antibodies. These clones were recloned and analyzed with a panel of probes from the HLA region. One hybrid (4G6) contained the entire HLA complex. Two other hybrids (4J4 and 4H2) contained only the HLA class I region, while the fourth hybrid (5P9) contained HLA class I and III genes in addition to other genes located in the 6p21 chromosomal region. In situ hybridization showed that the hybrid cells contained more than one fragment of human DNA. Alu and LINE PCR products were derived from these cells and compared to each other as well as to products from two somatic cell hybrids having the 6p21 region in common. The PCR fragments were then screened on conventional Southern blots of the somatic cell hybrids to select a panel of novel probes encompassing the 6p21 region. In addition, the origin of the human DNA fragments in hybrid 4J4 was determined by regional mapping of PCR products

  16. MK17, a specific marker closely linked to the gynoecium suppression region on the Y chromosome in Silene latifolia

    Czech Academy of Sciences Publication Activity Database

    Hobza, Roman; Hrušáková, P.; Šafář, Jan; Bartoš, Jan; Janoušek, Bohuslav; Žlůvová, Jitka; Michu, Elleni; Doležel, Jaroslav; Vyskot, Boris

    2006-01-01

    Roč. 113, č. 2 (2006), s. 280-287 ISSN 0040-5752 R&D Projects: GA ČR(CZ) GA521/06/0056; GA ČR(CZ) GD204/05/H505; GA ČR(CZ) GA521/05/2076; GA AV ČR(CZ) 1QS500040507 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50380511 Keywords : sex chromosomes * melandrium-album * evolution Subject RIV: BO - Biophysics Impact factor: 2.715, year: 2006

  17. Development of an allele-specific PCR assay for simultaneous sero-typing of avian pathogenic Escherichia coli predominant O1, O2, O18 and O78 strains.

    Science.gov (United States)

    Wang, Shaohui; Meng, Qingmei; Dai, Jianjun; Han, Xiangan; Han, Yue; Ding, Chan; Liu, Haiwen; Yu, Shengqing

    2014-01-01

    Systemic infections by avian pathogenic Escherichia coli (APEC) are economically devastating to poultry industries worldwide. E. coli strains belonging to serotypes O1, O2, O18 and O78 are preferentially associated with avian colibacillosis. The rfb gene cluster controlling O antigen synthesis is usually various among different E. coli serotypes. In present study, the rfb gene clusters of E. coli serotypes O1, O2, O18 and O78 were characterized and compared. Based on the serotype-specific genes in rfb gene cluster, an allele-specific polymerase chain reaction (PCR) assay was developed. This PCR assay was highly specific and reliable for sero-typing of APEC O1, O2, O18 and O78 strains. The sensitivity of the assay was determined as 10 pg DNA or 10 colony forming units (CFUs) bacteria for serotypes O2 and O18 strains, and 500 pg DNA or 1,000 CFUs bacteria for serotypes O1 and O78 strains. Using this PCR system, APEC isolates and the infected tissue samples were categorized successfully. Furthermore, it was able to differentiate the serotypes for the samples with multi-agglutination in the traditional serum agglutination assay. Therefore, the allele-specific PCR is more simple, rapid and accurate assay for APEC diagnosis, epidemiologic study and vaccine development.

  18. Development of an allele-specific PCR assay for simultaneous sero-typing of avian pathogenic Escherichia coli predominant O1, O2, O18 and O78 strains.

    Directory of Open Access Journals (Sweden)

    Shaohui Wang

    Full Text Available Systemic infections by avian pathogenic Escherichia coli (APEC are economically devastating to poultry industries worldwide. E. coli strains belonging to serotypes O1, O2, O18 and O78 are preferentially associated with avian colibacillosis. The rfb gene cluster controlling O antigen synthesis is usually various among different E. coli serotypes. In present study, the rfb gene clusters of E. coli serotypes O1, O2, O18 and O78 were characterized and compared. Based on the serotype-specific genes in rfb gene cluster, an allele-specific polymerase chain reaction (PCR assay was developed. This PCR assay was highly specific and reliable for sero-typing of APEC O1, O2, O18 and O78 strains. The sensitivity of the assay was determined as 10 pg DNA or 10 colony forming units (CFUs bacteria for serotypes O2 and O18 strains, and 500 pg DNA or 1,000 CFUs bacteria for serotypes O1 and O78 strains. Using this PCR system, APEC isolates and the infected tissue samples were categorized successfully. Furthermore, it was able to differentiate the serotypes for the samples with multi-agglutination in the traditional serum agglutination assay. Therefore, the allele-specific PCR is more simple, rapid and accurate assay for APEC diagnosis, epidemiologic study and vaccine development.

  19. Mesenchymal stem cells with high telomerase expression do not actively restore their chromosome arm specific telomere length pattern after exposure to ionizing radiation

    DEFF Research Database (Denmark)

    Graakjaer, Jesper; Christensen, Rikke; Kolvraa, Steen

    2007-01-01

    were measured using Fluorescence In Situ Hybridization (Q-FISH). RESULTS: A telomere length pattern was found to exist in primary hMSC's as well as in hMSC-telo1. This pattern is similar to what was previously found in lymphocytes and fibroblasts. The cells were then exposed to a high dose of ionizing...... radiation. Irradiation caused profound changes in chromosome specific telomere lengths, effectively destroying the telomere length pattern. Following long term culturing after irradiation, a telomere length pattern was found to re-emerge. However, the new telomere length pattern did not resemble...

  20. Designing of plant artificial chromosome (PAC) by using the Chlorella smallest chromosome as a model system.

    Science.gov (United States)

    Noutoshi, Y; Arai, R; Fujie, M; Yamada, T

    1997-01-01

    As a model for plant-type chromosomes, we have been characterizing molecular organization of the Chlorella vulgaris C-169 chromosome I. To identify chromosome structural elements including the centromeric region and replication origins, we constructed a chromosome I specific cosmid library and aligned each cosmid clones to generate contigs. So far, more than 80% of the entire chromosome I has been covered. A complete clonal physical reconstitution of chromosome I provides information on the structure and genomic organization of plant genome. We propose our strategy to construct an artificial chromosome by assembling the functional chromosome structural elements identified on Chrorella chromosome I.

  1. Electochemical detection of chromosome translocation

    DEFF Research Database (Denmark)

    Kwasny, Dorota; Dimaki, Maria; Silahtaroglu, Asli

    2014-01-01

    Cytogenetics is a study of the cell structure with a main focus on chromosomes content and their structure. Chromosome abnormalities, such as translocations may cause various genetic disorders and heametological malignancies. Chromosome translocations are structural rearrangements of two...... chromosomes that results in formation of derivative chromosomes with a mixed DNA sequence. The method currently used for their detection is Fluorescent In Situ Hybridization, which requires a use of expensive, fluorescently labeled probes that target the derivative chromosomes. We present here a double...... hybridization approach developed for label-free detection of the chromosome translocations. For specific translocation detection it is necessary to determine that the two DNA sequences forming a derivative chromosome are connected, which is achieved by two subsequent hybridization steps. The electrochemical...

  2. 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.

  3. 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.

  4. Mouse model of chromosome mosaicism reveals lineage-specific depletion of aneuploid cells and normal developmental potential.

    Science.gov (United States)

    Bolton, Helen; Graham, Sarah J L; Van der Aa, Niels; Kumar, Parveen; Theunis, Koen; Fernandez Gallardo, Elia; Voet, Thierry; Zernicka-Goetz, Magdalena

    2016-03-29

    Most human pre-implantation embryos are mosaics of euploid and aneuploid cells. To determine the fate of aneuploid cells and the developmental potential of mosaic embryos, here we generate a mouse model of chromosome mosaicism. By treating embryos with a spindle assembly checkpoint inhibitor during the four- to eight-cell division, we efficiently generate aneuploid cells, resulting in embryo death during peri-implantation development. Live-embryo imaging and single-cell tracking in chimeric embryos, containing aneuploid and euploid cells, reveal that the fate of aneuploid cells depends on lineage: aneuploid cells in the fetal lineage are eliminated by apoptosis, whereas those in the placental lineage show severe proliferative defects. Overall, the proportion of aneuploid cells is progressively depleted from the blastocyst stage onwards. Finally, we show that mosaic embryos have full developmental potential, provided they contain sufficient euploid cells, a finding of significance for the assessment of embryo vitality in the clinic.

  5. Mapping of the bcl-2 oncogene on mouse chromosome 1.

    Science.gov (United States)

    Mock, B A; Givol, D; D'Hoostelaere, L A; Huppi, K; Seldin, M F; Gurfinkel, N; Unger, T; Potter, M; Mushinski, J F

    1988-01-01

    Two bcl-2 alleles have been identified in inbred strains of mice by restriction fragment length polymorphism (RFLP). Analysis of a bcl-2 RFLP in a series of bilineal congenic strains (C.D2), developed as a tool for chromosomal mapping studies, revealed linkage of bcl-2 to the Idh-1/Pep-3 region of murine chromosome 1. The co-segregation of bcl-2 alleles with allelic forms of two other chromosome 1 loci, Ren-1,2 and Spna-1, in a set of back-cross progeny, positions bcl-2 7.8 cM centromeric from Ren-1,2.

  6. 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

  7. The − 5 A/G single-nucleotide polymorphism in the core promoter region of MT2A and its effect on allele-specific gene expression and Cd, Zn and Cu levels in laryngeal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Starska, Katarzyna, E-mail: katarzyna.starska@umed.lodz.pl [I Department of Otolaryngology and Laryngological Oncology, Medical University of Łódź, Kopcinskiego 22, 90-153 Łódź (Poland); Krześlak, Anna; Forma, Ewa [Department of Cytobiochemistry, University of Łódź, Pomorska 142/143, 90-236 Łódź (Poland); Olszewski, Jurek [II Department of Otolaryngology and Laryngological Oncology, Medical University of Łódź, Żeromskiego 113, 90-549 Łódź (Poland); Morawiec-Sztandera, Alina [Department of Head and Neck Surgery, Medical University of Łódź, Paderewskiego 4, 93-509 Łódź (Poland); Aleksandrowicz, Paweł [Department of Otolaryngology and Laryngological Oncology, Medical University of Lublin, Jaczewskiego 8, 20-954 Lublin (Poland); Lewy-Trenda, Iwona [Department of Pathology, Medical University of Łódź, Pomorska 251, 92-213 Łódź (Poland); and others

    2014-10-15

    Metallothioneins (MTs) are low molecular weight, cysteine-rich heavy metal-binding proteins which participate in the mechanisms of Zn homeostasis, and protect against toxic metals. MTs contain metal-thiolate cluster groups and suppress metal toxicity by binding to them. The aim of this study was to determine the − 5 A/G (rs28366003) single-nucleotide polymorphism (SNP) in the core promoter region of the MT2A gene and to investigate its effect on allele-specific gene expression and Cd, Zn and Cu content in squamous cell laryngeal cancer (SCC) and non-cancerous laryngeal mucosa (NCM) as a control. The MT2A promoter region − 5 A/G SNP was determined by restriction fragment length polymorphism using 323 SCC and 116 NCM. MT2A gene analysis was performed by quantitative real-time PCR. The frequency of A allele carriage was 94.2% and 91.8% in SCC and NCM, respectively, while G allele carriage was detected in 5.8% and 8.2% of SCC and NCM samples, respectively. As a result, a significant association was identified between the − 5 A/G SNP in the MT2A gene with mRNA expression in both groups. Metal levels were analyzed by flame atomic absorption spectrometry. The significant differences were identified between A/A and both the A/G and G/G genotypes, with regard to the concentration of the contaminating metal. The Spearman rank correlation results showed that the MT2A expression and Cd, Zn, Cu levels were negatively correlated. Results obtained in this study suggest that − 5 A/G SNP in MT2A gene may have an effect on allele-specific gene expression and accumulation of metal levels in laryngeal cancer. - Highlights: • MT2A gene expression and metal content in laryngeal cancer tissues • Association between SNP (rs28366003) and expression of MT2A • Significant associations between the SNP and Cd, Zn and Cu levels • Negative correlation between MT2A gene expression and Cd, Zn and Cu levels.

  8. The − 5 A/G single-nucleotide polymorphism in the core promoter region of MT2A and its effect on allele-specific gene expression and Cd, Zn and Cu levels in laryngeal cancer

    International Nuclear Information System (INIS)

    Starska, Katarzyna; Krześlak, Anna; Forma, Ewa; Olszewski, Jurek; Morawiec-Sztandera, Alina; Aleksandrowicz, Paweł; Lewy-Trenda, Iwona

    2014-01-01

    Metallothioneins (MTs) are low molecular weight, cysteine-rich heavy metal-binding proteins which participate in the mechanisms of Zn homeostasis, and protect against toxic metals. MTs contain metal-thiolate cluster groups and suppress metal toxicity by binding to them. The aim of this study was to determine the − 5 A/G (rs28366003) single-nucleotide polymorphism (SNP) in the core promoter region of the MT2A gene and to investigate its effect on allele-specific gene expression and Cd, Zn and Cu content in squamous cell laryngeal cancer (SCC) and non-cancerous laryngeal mucosa (NCM) as a control. The MT2A promoter region − 5 A/G SNP was determined by restriction fragment length polymorphism using 323 SCC and 116 NCM. MT2A gene analysis was performed by quantitative real-time PCR. The frequency of A allele carriage was 94.2% and 91.8% in SCC and NCM, respectively, while G allele carriage was detected in 5.8% and 8.2% of SCC and NCM samples, respectively. As a result, a significant association was identified between the − 5 A/G SNP in the MT2A gene with mRNA expression in both groups. Metal levels were analyzed by flame atomic absorption spectrometry. The significant differences were identified between A/A and both the A/G and G/G genotypes, with regard to the concentration of the contaminating metal. The Spearman rank correlation results showed that the MT2A expression and Cd, Zn, Cu levels were negatively correlated. Results obtained in this study suggest that − 5 A/G SNP in MT2A gene may have an effect on allele-specific gene expression and accumulation of metal levels in laryngeal cancer. - Highlights: • MT2A gene expression and metal content in laryngeal cancer tissues • Association between SNP (rs28366003) and expression of MT2A • Significant associations between the SNP and Cd, Zn and Cu levels • Negative correlation between MT2A gene expression and Cd, Zn and Cu levels

  9. Tissue-specific expression of the human laminin alpha5-chain, and mapping of the gene to human chromosome 20q13.2-13.3 and to distal mouse chromosome 2 near the locus for the ragged (Ra) mutation

    DEFF Research Database (Denmark)

    Durkin, M E; Loechel, F; Mattei, M G

    1997-01-01

    , heart, lung, skeletal muscle, kidney, and pancreas. The human laminin alpha5-chain gene (LAMA5) was assigned to chromosome 20q13.2-q13.3 by in situ hybridization, and the mouse gene (Lama5) was mapped by linkage analysis to a syntonic region of distal chromosome 2, close to the locus for the ragged (Ra...

  10. Differentiation of mycoplasmalike organisms (MLOs) in European fruit trees by PCR using specific primers derived from the sequence of a chromosomal fragment of the apple proliferation MLO.

    Science.gov (United States)

    Jarausch, W; Saillard, C; Dosba, F; Bové, J M

    1994-01-01

    A 1.8-kb chromosomal DNA fragment of the mycoplasmalike organism (MLO) associated with apple proliferation was sequenced. Three putative open reading frames were observed on this fragment. The protein encoded by open reading frame 2 shows significant homologies with bacterial nitroreductases. From the nucleotide sequence four primer pairs for PCR were chosen to specifically amplify DNA from MLOs associated with European diseases of fruit trees. Primer pairs specific for (i) Malus-affecting MLOs, (ii) Malus- and Prunus-affecting MLOs, and (iii) Malus-, Prunus-, and Pyrus-affecting MLOs were obtained. Restriction enzyme analysis of the amplification products revealed restriction fragment length polymorphisms between Malus-, Prunus, and Pyrus-affecting MLOs as well as between different isolates of the apple proliferation MLO. No amplification with either primer pair could be obtained with DNA from 12 different MLOs experimentally maintained in periwinkle. Images PMID:7916180

  11. Levels and patterns of nucleotide variation in domestication QTL regions on rice chromosome 3 suggest lineage-specific selection.

    Directory of Open Access Journals (Sweden)

    Xianfa Xie

    Full Text Available Oryza sativa or Asian cultivated rice is one of the major cereal grass species domesticated for human food use during the Neolithic. Domestication of this species from the wild grass Oryza rufipogon was accompanied by changes in several traits, including seed shattering, percent seed set, tillering, grain weight, and flowering time. Quantitative trait locus (QTL mapping has identified three genomic regions in chromosome 3 that appear to be associated with these traits. We would like to study whether these regions show signatures of selection and whether the same genetic basis underlies the domestication of different rice varieties. Fragments of 88 genes spanning these three genomic regions were sequenced from multiple accessions of two major varietal groups in O. sativa--indica and tropical japonica--as well as the ancestral wild rice species O. rufipogon. In tropical japonica, the levels of nucleotide variation in these three QTL regions are significantly lower compared to genome-wide levels, and coalescent simulations based on a complex demographic model of rice domestication indicate that these patterns are consistent with selection. In contrast, there is no significant reduction in nucleotide diversity in the homologous regions in indica rice. These results suggest that there are differences in the genetic and selective basis for domestication between these two Asian rice varietal groups.

  12. Association of LEI0258 microsatellite alleles with antibody response ...

    African Journals Online (AJOL)

    SERVER

    2008-03-18

    Mar 18, 2008 ... (MHC) B region on chicken Micro-chromosome 16 has been demonstrated by many workers to be ... promising DNA markers in characterizing MHC B genes. Identifying marker alleles (bands) ..... SAS/STAT Users' Guide,. Release 6.12 Edition, SAS Institute Inc, Cary, North Carolina. USA. Taylor RL (2004).

  13. Chromosomal Conditions

    Science.gov (United States)

    ... and more. Stony Point, NY 10980 Close X Home > Complications & Loss > Birth defects & other health conditions > Chromosomal conditions Chromosomal conditions ... Disorders See also: Genetic counseling , Your family health history Last reviewed: February, 2013 ... labor & premature birth The newborn intensive care unit (NICU) Birth defects & ...

  14. Cytotoxicity and genotoxicity of UVA irradiation in Chinese hamster ovary cells measured by specific locus mutations, sister chromatid exchanges and chromosome aberrations

    International Nuclear Information System (INIS)

    Lundgren, Karsten; Wulf, H.C.

    1988-01-01

    The increasing use of artificial UVA (320-400 nm) suntanning devices has brought attention to possible hazardous effects of UVA. In contrast with earlier studies, several groups recently have described that UVA possibly is mutagenic. We evaluate the genotoxic properties of broad band UVA using CHO cells and three different assays: specific locus (HGPRT) mutations, chromosome aberrations, and sister chromatid exchanges (SCEs). The UVA-source was an UVASUN 2000 S (Mutzhas), emitting UVA above 340 nm. The survival curve of the cells exhibited a shoulder up to 200 kJ/m 2 , that was followed by exponential killing at higher fluences. Mutations were induced linearly in the fluence range of 0-200 kJ/m 2 to a level seven fold higher than the spontaneous, followed by a decrease at fluences above 300 kJ/m 2 . Over the total range of tested fluences (0-300 kJ/m 2 ) a linear dose-response relationship was observed for UVA-induced SCEs. A significantly higher percentage of the cells showed chromosomes with aberrations at the higher levels of exposure (200, 300 and 400 kJ/m 2 ), but no dose response was demonstrated. Our results confirm recent findings showing that UVA is mutagenic in mammalian cells and suggest that UVA exposure may contribute to the total burden of genetic damage caused by exposure to ultraviolet light. (author)

  15. The loss-of-allele assay for ES cell screening and mouse genotyping.

    Science.gov (United States)

    Frendewey, David; Chernomorsky, Rostislav; Esau, Lakeisha; Om, Jinsop; Xue, Yingzi; Murphy, Andrew J; Yancopoulos, George D; Valenzuela, David M

    2010-01-01

    Targeting vectors used to create directed mutations in mouse embryonic stem (ES) cells consist, in their simplest form, of a gene for drug selection flanked by mouse genomic sequences, the so-called homology arms that promote site-directed homologous recombination between the vector and the target gene. The VelociGene method for the creation of targeted mutations in ES cells employs targeting vectors, called BACVecs, that are based on bacterial artificial chromosomes. Compared with conventional short targeting vectors, BacVecs provide two major advantages: (1) their much larger homology arms promote high targeting efficiencies without the need for isogenicity or negative selection strategies; and (2) they enable deletions and insertions of up to 100kb in a single targeting event, making possible gene-ablating definitive null alleles and other large-scale genomic modifications. Because of their large arm sizes, however, BACVecs do not permit screening by conventional assays, such as long-range PCR or Southern blotting, that link the inserted targeting vector to the targeted locus. To exploit the advantages of BACVecs for gene targeting, we inverted the conventional screening logic in developing the loss-of-allele (LOA) assay, which quantifies the number of copies of the native locus to which the mutation was directed. In a correctly targeted ES cell clone, the LOA assay detects one of the two native alleles (for genes not on the X or Y chromosome), the other allele being disrupted by the targeted modification. We apply the same principle in reverse as a gain-of-allele assay to quantify the copy number of the inserted targeting vector. The LOA assay reveals a correctly targeted clone as having lost one copy of the native target gene and gained one copy of the drug resistance gene or other inserted marker. The combination of these quantitative assays makes LOA genotyping unequivocal and amenable to automated scoring. We use the quantitative polymerase chain reaction

  16. BRAF Gene Copy Number and Mutant Allele Frequency Correlate with Time to Progression in Metastatic Melanoma Patients Treated with MAPK Inhibitors.

    Science.gov (United States)

    Stagni, Camilla; Zamuner, Carolina; Elefanti, Lisa; Zanin, Tiziana; Bianco, Paola Del; Sommariva, Antonio; Fabozzi, Alessio; Pigozzo, Jacopo; Mocellin, Simone; Montesco, Maria Cristina; Chiarion-Sileni, Vanna; De Nicolo, Arcangela; Menin, Chiara

    2018-06-01

    Metastatic melanoma is characterized by complex genomic alterations, including a high rate of mutations in driver genes and widespread deletions and amplifications encompassing various chromosome regions. Among them, chromosome 7 is frequently gained in BRAF -mutant melanoma, inducing a mutant allele-specific imbalance. Although BRAF amplification is a known mechanism of acquired resistance to therapy with MAPK inhibitors, it is still unclear if BRAF copy-number variation and BRAF mutant allele imbalance at baseline can be associated with response to treatment. In this study, we used a multimodal approach to assess BRAF copy number and mutant allele frequency in pretreatment melanoma samples from 46 patients who received MAPK inhibitor-based therapy, and we analyzed the association with progression-free survival. We found that 65% patients displayed BRAF gains, often supported by chromosome 7 polysomy. In addition, we observed that 64% patients had a balanced BRAF -mutant/wild-type allele ratio, whereas 14% and 23% patients had low and high BRAF mutant allele frequency, respectively. Notably, a significantly higher risk of progression was observed in patients with a diploid BRAF status versus those with BRAF gains [HR, 2.86; 95% confidence interval (CI), 1.29-6.35; P = 0.01] and in patients with low percentage versus those with a balanced BRAF mutant allele percentage (HR, 4.54; 95% CI, 1.33-15.53; P = 0.016). Our data suggest that quantitative analysis of the BRAF gene could be useful to select the melanoma patients who are most likely to benefit from therapy with MAPK inhibitors. Mol Cancer Ther; 17(6); 1332-40. ©2018 AACR . ©2018 American Association for Cancer Research.

  17. Allelic diversity in an NLR gene BPH9 enables rice to combat planthopper variation.

    Science.gov (United States)

    Zhao, Yan; Huang, Jin; Wang, Zhizheng; Jing, Shengli; Wang, Yang; Ouyang, Yidan; Cai, Baodong; Xin, Xiu-Fang; Liu, Xin; Zhang, Chunxiao; Pan, Yufang; Ma, Rui; Li, Qiaofeng; Jiang, Weihua; Zeng, Ya; Shangguan, Xinxin; Wang, Huiying; Du, Bo; Zhu, Lili; Xu, Xun; Feng, Yu-Qi; He, Sheng Yang; Chen, Rongzhi; Zhang, Qifa; He, Guangcun

    2016-10-24

    Brown planthopper (BPH), Nilaparvata lugens Stål, is one of the most devastating insect pests of rice (Oryza sativa L.). Currently, 30 BPH-resistance genes have been genetically defined, most of which are clustered on specific chromosome regions. Here, we describe molecular cloning and characterization of a BPH-resistance gene, BPH9, mapped on the long arm of rice chromosome 12 (12L). BPH9 encodes a rare type of nucleotide-binding and leucine-rich repeat (NLR)-containing protein that localizes to the endomembrane system and causes a cell death phenotype. BPH9 activates salicylic acid- and jasmonic acid-signaling pathways in rice plants and confers both antixenosis and antibiosis to BPH. We further demonstrated that the eight BPH-resistance genes that are clustered on chromosome 12L, including the widely used BPH1, are allelic with each other. To honor the priority in the literature, we thus designated this locus as BPH1/9 These eight genes can be classified into four allelotypes, BPH1/9-1, -2, -7, and -9 These allelotypes confer varying levels of resistance to different biotypes of BPH. The coding region of BPH1/9 shows a high level of diversity in rice germplasm. Homologous fragments of the nucleotide-binding (NB) and leucine-rich repeat (LRR) domains exist, which might have served as a repository for generating allele diversity. Our findings reveal a rice plant strategy for modifying the genetic information to gain the upper hand in the struggle against insect herbivores. Further exploration of natural allelic variation and artificial shuffling within this gene may allow breeding to be tailored to control emerging biotypes of BPH.

  18. The X chromosome in space.

    Science.gov (United States)

    Jégu, Teddy; Aeby, Eric; Lee, Jeannie T

    2017-06-01

    Extensive 3D folding is required to package a genome into the tiny nuclear space, and this packaging must be compatible with proper gene expression. Thus, in the well-hierarchized nucleus, chromosomes occupy discrete territories and adopt specific 3D organizational structures that facilitate interactions between regulatory elements for gene expression. The mammalian X chromosome exemplifies this structure-function relationship. Recent studies have shown that, upon X-chromosome inactivation, active and inactive X chromosomes localize to different subnuclear positions and adopt distinct chromosomal architectures that reflect their activity states. Here, we review the roles of long non-coding RNAs, chromosomal organizational structures and the subnuclear localization of chromosomes as they relate to X-linked gene expression.

  19. Linkage map positions and allelic diversity of two Mal d 3 (non-specific lipid transfer protein) genes in the cultivated apple (Malus domestica)

    NARCIS (Netherlands)

    Gao, Z.S.; Weg, van de W.E.; Schaart, J.G.; Meer, van der I.M.; Kodde, L.P.; Laimer, M.; Breiteneder, H.; Hoffmann-Sommergruber, K.; Gilissen, L.J.W.J.

    2005-01-01

    Non-specific lipid transfer proteins (nsLTPs) of Rosaceae fruits, such as peach, apricot, cherry, plum and apple, represent major allergens for Mediterranean atopic populations. As a first step in elucidating the genetics of nsLTPs, we directed the research reported here towards identifying the

  20. Swine Leukocyte Antigen (SLA) class I allele typing of Danish swine herds and the identification of commonly expressed haplotypes using sequence specific low- and high resolution primers

    DEFF Research Database (Denmark)

    Pedersen, Lasse Eggers; Fink, Dorte Rosenbek; Jungersen, Gregers

    molecule is only able to bind a restricted number of peptides with specific biochemical characteristics matching important anchor positions in the peptide binding groove. Although the diversity of T cells is vast, the individual MHC make-up thus limits the range of potential T cell epitopes for any given...

  1. Large-scale analysis of pedigree and sperm-typing data reveals PRDM9 allele-specific recombination maps in cattle

    Science.gov (United States)

    Meiotic recombination is a major driving force in promoting genetic and phenotypic variations in sexually reproducing organisms. Although PRDM9 is known to modulate the binding-specificity and location of recombination hotspots in humans and mice, its role, especially in domesticated animals like ca...

  2. Large-scale polymorphism near the ends of several human chromosomes analyzed by using fluorescence in situ hybridization (FISH)

    Energy Technology Data Exchange (ETDEWEB)

    Trask, B.J.; Friedman, C. [Univ. of Washington, Seattle, WA (United States); Giorgi, D. [CNRS, Montpelier (France)] [and others

    1994-09-01

    We have discovered a large DNA segment that is polymorphically present at the ends of several human chromosomes. The segment, f7501, was originally derived form a human chromosome 19-specific cosmid library. FISH was used to determine the cosmid`s chromosomal distribution on 44 unrelated humans and several closely related primates. The human subjects represent a diversity of reproductively isolated ethnic populations. FISH analysis revealed that sequences highly homologous to the cosmid`s insert are present on both homologs at 3q, 15q,. and 19p in almost all individuals (88, 85, and 87 of 88 homologs, respectively). Other chromosomes sites were labeled much more rarely in the sampled individuals. For example, 56 of the 88 analyzed chromosomes 11 were labeled (18+/+, 6-/-, and 20+/- individuals). In contrast, 2q was labeled on only 1/88 sampled chromosomes. The termini of 2q, 5q, 6p, 6q, 7p, 8p, 9p, 9q, 11p, 12q, 16p, 19q, and 20q and an interstitial site at 2q13-14 were labeled in at least one individual of the set. EcoR1-fragments derived from the cosmid showed the same hybridization pattern as the entire cosmid, indicating that at least 40 kbp is shared by these chromosome ends. Ethnic differences in the allele frequency of these polymorphic variants was observed. For example, signals were observed on 8/10 and 7/10 of the chromosomes 7p and 16q, respectively, derived form Biakan Pygmies, but these sites were infrequently labeled in non-Pygmy human populations (2/68, respectively). This region has undergone significant changes in chromosome location during human evolution. Strong signal was seen on chimpanzee and gorilla chromosome 3, which is homologous to human chromosome 4, a chromosome unlabeled in any of the humans we have analyzed.

  3. Alleles of Ppd-D1 gene in the collection of Aegilops tauschii accessions and bread wheat varieties

    Directory of Open Access Journals (Sweden)

    Babenko D. O.

    2012-04-01

    Full Text Available Light period significantly influences on the growth and development of plants. One of the major genes of photoperiod sensitivity is Ppd-D1, located on the chromosome 2D. The aim of the work was to determine the alleles and molecular structure of Ppd-D1 gene in samples from the collection of Ae. tauschii accessions, which have different flowering periods, and in 29 Ukrainian wheat varieties. Methods. We used methods of allele-specific PCR with primers to the Ppd-D1 gene, sequencing and Blast-analysis. Results. The collection of Ae. tauschii accessions and several varieties of winter and spring wheat was studied. The molecular structure of the allelic variants (414, 429 and 453 b. p. of Ppd-D1b gene was determined in the collection of Aegilops. tauschii accessions. Conclusions. The Ppd-D1a allele was present in all studied varieties of winter wheat. 60 % of spring wheat is characterized by Ppd-D1b allele (size of amplification products 414 b. p.. Blast-analysis of the sequence data banks on the basis of the reference sequence of sample k-1322 from the collection of Ae. tauschii accessions has shown a high homology (80 to 100 % between the nucleotide sequences of PRR genes, that characterize the A and D genomes of representatives of the genera Triticum and Aegilops.

  4. A dense SNP-based linkage map for Atlantic salmon (Salmo salar reveals extended chromosome homeologies and striking differences in sex-specific recombination patterns

    Directory of Open Access Journals (Sweden)

    Lien Sigbjørn

    2011-12-01

    Full Text Available Abstract Background The Atlantic salmon genome is in the process of returning to a diploid state after undergoing a whole genome duplication (WGD event between 25 and100 million years ago. Existing data on the proportion of paralogous sequence variants (PSVs, multisite variants (MSVs and other types of complex sequence variation suggest that the rediplodization phase is far from over. The aims of this study were to construct a high density linkage map for Atlantic salmon, to characterize the extent of rediploidization and to improve our understanding of genetic differences between sexes in this species. Results A linkage map for Atlantic salmon comprising 29 chromosomes and 5650 single nucleotide polymorphisms (SNPs was constructed using genotyping data from 3297 fish belonging to 143 families. Of these, 2696 SNPs were generated from ESTs or other gene associated sequences. Homeologous chromosomal regions were identified through the mapping of duplicated SNPs and through the investigation of syntenic relationships between Atlantic salmon and the reference genome sequence of the threespine stickleback (Gasterosteus aculeatus. The sex-specific linkage maps spanned a total of 2402.3 cM in females and 1746.2 cM in males, highlighting a difference in sex specific recombination rate (1.38:1 which is much lower than previously reported in Atlantic salmon. The sexes, however, displayed striking differences in the distribution of recombination sites within linkage groups, with males showing recombination strongly localized to telomeres. Conclusion The map presented here represents a valuable resource for addressing important questions of interest to evolution (the process of re-diploidization, aquaculture and salmonid life history biology and not least as a resource to aid the assembly of the forthcoming Atlantic salmon reference genome sequence.

  5. Chromosome Territories

    OpenAIRE

    Cremer, Thomas; Cremer, Marion

    2010-01-01

    Chromosome territories (CTs) constitute a major feature of nuclear architecture. In a brief statement, the possible contribution of nuclear architecture studies to the field of epigenomics is considered, followed by a historical account of the CT concept and the final compelling experimental evidence of a territorial organization of chromosomes in all eukaryotes studied to date. Present knowledge of nonrandom CT arrangements, of the internal CT architecture, and of structural interactions wit...

  6. Chromosomal aberration

    International Nuclear Information System (INIS)

    Ishii, Yutaka

    1988-01-01

    Chromosomal aberrations are classified into two types, chromosome-type and chromatid-type. Chromosom-type aberrations include terminal deletion, dicentric, ring and interstitial deletion, and chromatid-type aberrations include achromatic lesion, chromatid deletion, isochromatid deletion and chromatid exchange. Clastogens which induce chromosomal aberration are divided into ''S-dependent'' agents and ''S-independent''. It might mean whether they can induce double strand breaks independent of the S phase or not. Double strand breaks may be the ultimate lesions to induce chromosomal aberrations. Caffeine added even in the G 2 phase appeared to modify the frequency of chromatid aberrations induced by X-rays and mitomycin C. Those might suggest that the G 2 phase involves in the chromatid aberration formation. The double strand breaks might be repaired by ''G 2 repair system'', the error of which might yield breakage types of chromatid aberrations and the by-pass of which might yield chromatid exchanges. Chromosome-type aberrations might be formed in the G 1 phase. (author)

  7. Linking Y-chromosomal short tandem repeat loci to human male impulsive aggression.

    Science.gov (United States)

    Yang, Chun; Ba, Huajie; Cao, Yin; Dong, Guoying; Zhang, Shuyou; Gao, Zhiqin; Zhao, Hanqing; Zhou, Xianju

    2017-11-01

    Men are more susceptible to impulsive behavior than women. Epidemiological studies revealed that the impulsive aggressive behavior is affected by genetic factors, and the male-specific Y chromosome plays an important role in this behavior. In this study, we investigated the association between the impulsive aggressive behavior and Y-chromosomal short tandem repeats (Y-STRs) loci. The collected biologic samples from 271 offenders with impulsive aggressive behavior and 492 healthy individuals without impulsive aggressive behavior were amplified by PowerPlex R Y23 PCR System and the resultant products were separated by electrophoresis and further genotyped. Then, comparisons in allele and haplotype frequencies of the selected 22 Y-STRs were made in the two groups. Our results showed that there were significant differences in allele frequencies at DYS448 and DYS456 between offenders and controls ( p  impulsive aggression. However, the DYS448-DYS456-22-15 is less related to impulsive aggression. Our results suggest a link between Y-chromosomal allele types and male impulsive aggression.

  8. Analysis of the Arabidopsis superman allelic series and the interactions with other genes demonstrate developmental robustness and joint specification of male-female boundary, flower meristem termination and carpel compartmentalization.

    Science.gov (United States)

    Breuil-Broyer, Stéphanie; Trehin, Christophe; Morel, Patrice; Boltz, Véronique; Sun, Bo; Chambrier, Pierre; Ito, Toshiro; Negrutiu, Ioan

    2016-04-01

    SUPERMAN is a cadastral gene controlling the sexual boundary in the flower. The gene's functions and role in flower development and evolution have remained elusive. The analysis of a contrasting SUP allelic series (for which the names superman, superwoman and supersex have been coined) makes it possible to distinguish early vs. late regulatory processes at the flower meristem centre to which SUP is an important contributor. Their understanding is essential in further addressing evolutionary questions linking bisexuality and flower meristem homeostasis. Inter-allelic comparisons were carried out and SUP interactions with other boundary factors and flower meristem patterning and homeostasis regulators (such as CLV, WUS, PAN, CUC, KNU, AG, AP3/PI, CRC and SPT) have been evaluated at genetic, molecular, morphological and histological levels. Early SUP functions include mechanisms of male-female (sexual) boundary specification, flower mersitem termination and control of stamen number. A SUP-dependent flower meristem termination pathway is identified and analysed. Late SUP functions play a role in organ morphogenesis by controlling intra-whorl organ separation and carpel medial region formation. By integrating early and late SUP functions, and by analyzing in one single experiment a series of SUP genetic interactions, the concept of meristematic 'transference' (cascade) - a regulatory bridging process redundantly and sequentially co-ordinating the triggering and completion of flower meristem termination, and carpel margin meristem and placenta patterning - is proposed. Taken together, the results strongly support the view that SUP(-type) function(s) have been instrumental in resolving male/female gradients into sharp male and female identities (whorls, organs) and in enforcing flower homeostasis during evolution. This has probably been achieved by incorporating the meristem patterning system of the floral axis into the female/carpel programme. © The Author 2016

  9. Validation of a Multiplex Allele-Specific Polymerase Chain Reaction Assay for Detection of KRAS Gene Mutations in Formalin-Fixed, Paraffin-Embedded Tissues from Colorectal Cancer Patients.

    Directory of Open Access Journals (Sweden)

    Sirirat Seekhuntod

    Full Text Available Patients with KRAS mutations do not respond to epidermal growth factor receptor (EGFR inhibitors and fail to benefit from adjuvant chemotherapy. Mutation analysis of KRAS is needed before starting treatment with monoclonal anti-EGFR antibodies in patients with metastatic colorectal cancer (mCRC. The objective of this study is to develop a multiplex allele-specific PCR (MAS-PCR assay to detect KRAS mutations.We developed a single-tube MAS-PCR assay for the detection of seven KRAS mutations (G12D, G12A, G12R, G12C, G12S, G12V, and G13D. We performed MAS-PCR assay analysis for KRAS on DNA isolated from 270 formalin-fixed paraffin-embedded (FFPE colorectal cancer tissues. Sequences of all 270 samples were determined by pyrosequencing. Seven known point-mutation DNA samples diluted with wild-type DNA were assayed to determine the limitation of detection and reproducibility of the MAS-PCR assay.Overall, the results of MAS-PCR assay were in good concordance with pyrosequencing, and only seven discordant samples were found. The MAS-PCR assay reproducibly detected 1 to 2% mutant alleles. The most common mutations were G13D in codon 13 (49.17%, G12D (25.83% and G12V (12.50% in codon 12.The MAS-PCR assay provides a rapid, cost-effective, and reliable diagnostic tool for accurate detection of KRAS mutations in routine FFPE colorectal cancer tissues.

  10. Association of MMP7 -181A→G Promoter Polymorphism with Gastric Cancer Risk: INFLUENCE OF NICOTINE IN DIFFERENTIAL ALLELE-SPECIFIC TRANSCRIPTION VIA INCREASED PHOSPHORYLATION OF cAMP-RESPONSE ELEMENT-BINDING PROTEIN (CREB).

    Science.gov (United States)

    Kesh, Kousik; Subramanian, Lakshmi; Ghosh, Nillu; Gupta, Vinayak; Gupta, Arnab; Bhattacharya, Samir; Mahapatra, Nitish R; Swarnakar, Snehasikta

    2015-06-05

    Elevated expression of matrix metalloproteinase7 (MMP7) has been demonstrated to play a pivotal role in cancer invasion. The -181A→G (rs11568818) polymorphism in the MMP7 promoter modulates gene expression and possibly affects cancer progression. Here, we evaluated the impact of -181A→G polymorphism on MMP7 promoter activity and its association with gastric cancer risk in eastern Indian case-control cohorts (n = 520). The GG genotype as compared with the AA genotype was predisposed (p = 0.02; odds ratio = 1.9, 95% confidence interval = 1.1-3.3) to gastric cancer risk. Stratification analysis showed that tobacco addiction enhanced gastric cancer risk in GG subjects when compared with AA subjects (p = 0.03, odds ratio = 2.46, and 95% confidence interval = 1.07-5.68). Meta-analysis revealed that tobacco enhanced the risk for cancer more markedly in AG and GG carriers. Activity and expression of MMP7 were significantly higher in GG than in AA carriers. In support, MMP7 promoter-reporter assays showed greater transcriptional activity toward A to G transition under basal/nicotine-induced/cAMP-response element-binding protein (CREB) overexpressed conditions in gastric adenocarcinoma cells. Moreover, nicotine (a major component of tobacco) treatment significantly up-regulated MMP7 expression due to enhanced CREB phosphorylation followed by its nuclear translocation in gastric adenocarcinoma cells. Furthermore, chromatin immunoprecipitation experiments revealed higher binding of phosphorylated CREB with the -181G than the -181A allele. Altogether, specific binding of phosphorylated CREB to the G allele-carrying promoter enhances MMP7 gene expression that is further augmented by nicotine due to increased CREB phosphorylation and thereby increases the risk for gastric cancer. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. Molecular genetic approach to human meningioma: loss of genes on chromosome 22

    International Nuclear Information System (INIS)

    Seizinger, B.R.; De La Monte, S.; Atkins, L.; Gusella, J.F.; Martuza, R.L.

    1987-01-01

    A molecular genetic approach employing polymorphic DNA markers has been used to investigate the role of chromosomal aberrations in meningioma, one of the most common tumors of the human nervous system. Comparison of the alleles detected by DNA markers in tumor DNA versus DNA from normal tissue revealed chromosomal alterations present in primary surgical specimens. In agreement with cytogenetic studies of cultured meningiomas, the most frequent alteration detected was loss of heterozygosity on chromosome 22. Forty of 51 patients were constitutionally heterozygous for at least one chromosome 22 DNA marker. Seventeen of the 40 constitutionally heterozygotic patients (43%) displayed hemizygosity for the corresponding marker in their meningioma tumor tissues. Loss of heterozygosity was also detected at a significantly lower frequency for markers on several other autosomes. In view of the striking association between acoustic neuroma and meningioma in bilateral acoustic neurofibromatosis and the discovery that acoustic neuromas display specific loss of genes on chromosome 22, the authors propose that a common mechanism involving chromosome 22 is operative in the development of both tumor types. Fine-structure mapping to reveal partial deletions in meningiomas may provide the means to clone and characterize a gene (or genes) of importance for tumorigenesis in this and possibly other clinically associated tumors of the human nervous system

  12. Fine mapping of dominant X-linked incompatibility alleles in Drosophila hybrids.

    Science.gov (United States)

    Matute, Daniel R; Gavin-Smyth, Jackie

    2014-04-01

    Sex chromosomes have a large effect on reproductive isolation and play an important role in hybrid inviability. In Drosophila hybrids, X-linked genes have pronounced deleterious effects on fitness in male hybrids, which have only one X chromosome. Several studies have succeeded at locating and identifying recessive X-linked alleles involved in hybrid inviability. Nonetheless, the density of dominant X-linked alleles involved in interspecific hybrid viability remains largely unknown. In this report, we study the effects of a panel of small fragments of the D. melanogaster X-chromosome carried on the D. melanogaster Y-chromosome in three kinds of hybrid males: D. melanogaster/D. santomea, D. melanogaster/D. simulans and D. melanogaster/D. mauritiana. D. santomea and D. melanogaster diverged over 10 million years ago, while D. simulans (and D. mauritiana) diverged from D. melanogaster over 3 million years ago. We find that the X-chromosome from D. melanogaster carries dominant alleles that are lethal in mel/san, mel/sim, and mel/mau hybrids, and more of these alleles are revealed in the most divergent cross. We then compare these effects on hybrid viability with two D. melanogaster intraspecific crosses. Unlike the interspecific crosses, we found no X-linked alleles that cause lethality in intraspecific crosses. Our results reveal the existence of dominant alleles on the X-chromosome of D. melanogaster which cause lethality in three different interspecific hybrids. These alleles only cause inviability in hybrid males, yet have little effect in hybrid females. This suggests that X-linked elements that cause hybrid inviability in males might not do so in hybrid females due to differing sex chromosome interactions.

  13. Host specific diversity in Lactobacillus johnsonii as evidenced by a major chromosomal inversion and phage resistance mechanisms.

    Science.gov (United States)

    Guinane, Caitriona M; Kent, Robert M; Norberg, Sarah; Hill, Colin; Fitzgerald, Gerald F; Stanton, Catherine; Ross, R Paul

    2011-04-20

    Genetic diversity and genomic rearrangements are a driving force in bacterial evolution and niche adaptation. We sequenced and annotated the genome of Lactobacillus johnsonii DPC6026, a strain isolated from the porcine intestinal tract. Although the genome of DPC6026 is similar in size (1.97 mbp) and GC content (34.8%) to the sequenced human isolate L. johnsonii NCC 533, a large symmetrical inversion of approximately 750 kb differentiated the two strains. Comparative analysis among 12 other strains of L. johnsonii including 8 porcine, 3 human and 1 poultry isolate indicated that the genome architecture found in DPC6026 is more common within the species than that of NCC 533. Furthermore a number of unique features were annotated in DPC6026, some of which are likely to have been acquired by horizontal gene transfer (HGT) and contribute to protection against phage infection. A putative type III restriction-modification system was identified, as were novel Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) elements. Interestingly, these particular elements are not widely distributed among L. johnsonii strains. Taken together these data suggest intra-species genomic rearrangements and significant genetic diversity within the L. johnsonii species and indicate towards a host-specific divergence of L. johnsonii strains with respect to genome inversion and phage exposure.

  14. Host specific diversity in Lactobacillus johnsonii as evidenced by a major chromosomal inversion and phage resistance mechanisms.

    Directory of Open Access Journals (Sweden)

    Caitriona M Guinane

    Full Text Available Genetic diversity and genomic rearrangements are a driving force in bacterial evolution and niche adaptation. We sequenced and annotated the genome of Lactobacillus johnsonii DPC6026, a strain isolated from the porcine intestinal tract. Although the genome of DPC6026 is similar in size (1.97 mbp and GC content (34.8% to the sequenced human isolate L. johnsonii NCC 533, a large symmetrical inversion of approximately 750 kb differentiated the two strains. Comparative analysis among 12 other strains of L. johnsonii including 8 porcine, 3 human and 1 poultry isolate indicated that the genome architecture found in DPC6026 is more common within the species than that of NCC 533. Furthermore a number of unique features were annotated in DPC6026, some of which are likely to have been acquired by horizontal gene transfer (HGT and contribute to protection against phage infection. A putative type III restriction-modification system was identified, as were novel Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR elements. Interestingly, these particular elements are not widely distributed among L. johnsonii strains. Taken together these data suggest intra-species genomic rearrangements and significant genetic diversity within the L. johnsonii species and indicate towards a host-specific divergence of L. johnsonii strains with respect to genome inversion and phage exposure.

  15. Development of an allele-specific, loop-mediated, isothermal amplification method (AS-LAMP to detect the L1014F kdr-w mutation in Anopheles gambiae s. l.

    Directory of Open Access Journals (Sweden)

    Badolo Athanase

    2012-07-01

    Full Text Available Abstract Background Malaria control relies heavily on treated bed nets and indoor residual spraying with pyrethroid insecticides. Unfortunately, the resistance to pyrethroid insecticides, mainly due to the kdr mutation, is spreading in the main malaria vector Anopheles gambiae s.l., decreasing the insecticides’ efficacy. To manage the insecticide resistance rapidly and flexibly, simple and effective tools for the early detection of resistant mosquitoes are needed. This study aimed to develop an allele-specific, loop-mediated, isothermal amplification (AS-LAMP method to detect the West African-type kdr mutation (kdr-w; L1014F in field-collected mosquitoes. Methods DNA fragments of the wild-type and the mutated kdr gene were used to select the primers and develop the method. The primers were designed with the mutation at the 5’ end of the backward inner primer (BIP. The AS-LAMP method was compared to the AS-PCR method using the genomic DNA of 120 field-collected mosquitoes. Results The AS-LAMP method could discriminate between the wild-type homozygote, the heterozygote, and the kdr-w homozygote within 75 min. The AS-LAMP method has the advantage of being faster and at least as sensitive and specific as the AS-PCR method. Conclusions The AS-LAMP method can be used to detect the kdr mutation for quick decision-making, even in less well-equipped laboratories.

  16. VNTR alleles associated with the {alpha}-globin locus are haplotype and population related

    Energy Technology Data Exchange (ETDEWEB)

    Martinson, J.J.; Clegg, J.B.; Boyce, A.J. [Univ. of Oxford (United Kingdom)

    1994-09-01

    The human {alpha}-globin complex contains several polymorphic restriction-enzyme sites (i.e., RFLPs) linked to form haplotypes and is flanked by two hypervariable VNTR loci, the 5{prime} hypervariable region (HVR) and the more highly polymorphic 3{prime}HVR. Using a combination of RFLP analysis and PCR, the authors have characterized the 5{prime}HVR and 3{prime}HVR alleles associated with the {alpha}-globin haplotypes of 133 chromosomes, and they here show that specific {alpha}-globin haplotypes are each associated with discrete subsets of the alleles observed at these two VNTR loci. This statistically highly significant association is observed over a region spanning {approximately} 100 kb. With the exception of closely related haplotypes, different haplotypes do not share identically sized 3{prime}HVR alleles. Earlier studies have shown that {alpha}-globin haplotype distributions differ between populations; the current findings also reveal extensive population substructure in the repertoire of {alpha}-globin VNTRs. If similar features are characteristic of other VNTR loci, this will have important implications for forensic and anthropological studies. 42 refs., 5 figs., 5 tabs.

  17. Rapid and efficient introduction of a foreign gene into bacterial artificial chromosome-cloned varicella vaccine by Tn7-mediated site-specific transposition

    International Nuclear Information System (INIS)

    Somboonthum, Pranee; Koshizuka, Tetsuo; Okamoto, Shigefumi; Matsuura, Masaaki; Gomi, Yasuyuki; Takahashi, Michiaki; Yamanishi, Koichi; Mori, Yasuko

    2010-01-01

    Using a rapid and reliable system based on Tn7-mediated site-specific transposition, we have successfully constructed a recombinant Oka varicella vaccine (vOka) expressing the mumps virus (MuV) fusion protein (F). The backbone of the vector was our previously reported vOka-BAC (bacterial artificial chromosome) genome. We inserted the transposon Tn7 attachment sequence, LacZα-mini-attTn7, into the region between ORF12 and ORF13 to generate a vOka-BAC-Tn genome. The MuV-F expressing cassette was transposed into the vOka-BAC genome at the mini-attTn7 transposition site. MuV-F protein was expressed in recombinant virus, rvOka-F infected cells. In addition, the MuV-F protein was cleaved in the rvOka-F infected cells as in MuV-infected cells. The growth of rvOka-F was similar to that of the original recombinant vOka without the F gene. Thus, we show that Tn7-mediated transposition is an efficient method for introducing a foreign gene expression cassette into the vOka-BAC genome as a live virus vector.

  18. The endocrine stress response is linked to one specific locus on chromosome 3 in a mouse model based on extremes in trait anxiety

    Directory of Open Access Journals (Sweden)

    Gonik Mariya

    2012-10-01

    epistasis (p-adjusted Conclusion The very prominent effect on stress-induced corticosterone secretion of the genomic locus on chromosome 3 and its involvement in epistasis highlights the critical role of this specific locus in the regulation of the HPA axis.

  19. Chromosomes, cancer and radiosensitivity

    International Nuclear Information System (INIS)

    Samouhos, E.

    1983-01-01

    Some specific chromosomal abnormalities are associated with certain cancers. The earliest description of such a specific association is the one of the Philadelphia chromosome and myelogenous leukemia (1960). Other congenital karyotype abnormalities are associated with specific cancers. Examples of these are Down's syndrome with leukemia and Klinefelter's syndrome with male breast cancer. Genetic diseases of increased chromosome breakage, or of defective chromosome repair, are associated with greatly increased cancer incidence. Three such diseases have been recognized: 1) Fanconi's anemia, associated with leukemias and lymphomas, 2) Bloom's syndrome, associated with acute leukemias and lymphosarcoma, and 3) ataxia telangiectasia, associated with Hodgkin's disease, leukemia, and lymphosarcomas. Ten percent of individuals with ataxia telangiectasia will develop one of these neoplasms. Individuals with certain of these syndromes display an unusually high radiosensitivity. Radiation therapy for cancers has been fatal in patients who received as low as 3000 rad. This remarkable radiosensitivity has been quantitated in cell cultures from such cases. Evidence suggests that the apparent sensitivity may reflect subnormal ability to repair radiation damage. The rapid proliferation of information in this field stems from the interdigitation of many disciplines and specialties, including cytogenetics, cell biology, molecular biology, epidemiology, radiobiology, and several others. This paper is intended for clinicians; it presents a structured analytic scheme for correlating and classifying this multidisciplinary information as it becomes available

  20. Microdissection and Chromosome Painting of the Alien Chromosome in an Addition Line of Wheat - Thinopyrum intermedium

    Science.gov (United States)

    Yin, Weibo; Zhang, Yingxin; Chen, Yuhong; Wang, Richard R.-C.; Zhang, Xiangqi; Han, Fangpu; Hu, Zanmin

    2013-01-01

    In this study, chromosome painting was developed and used to identify alien chromosomes in TAi-27, a wheat - Thinopyrum intermedium addition line, and the chromosomes of the three different genomes of Th. Intermedium. The smallest alien chromosome of TAi-27 was microdissected and its DNA amplified by DOP-PCR was used as a probe to hybridize with metaphase chromosomes of TAi-27 and Th . intermedium . Results showed that hybridization signals were observed in all regions of a pair of the smallest alien chromosomes and the pericentromeric area of another pair of alien chromosomes in TAi-27, indicating that the probe from microdissected chromosome is species specific. In Th . intermedium , 14 chromosomes had wide and strong hybridization signals distributed mainly on the pericentromere area and 9 chromosomes with narrow and weak signals on the pericentromere area. The remaining chromosomes displayed a very weak or no signal. Sequential FISH/GISH on Th . intermedium chromosomes using the DNAs of microdissected chromosome, Pseudoroegneria spicata (St genome) and pDbH12 (a Js genome specific probe) as the probes indicated that the microdissected chromosome belonged to the St genome, three genomes (Js, J and St) in Th . intermedium could be distinguished, in which there is no hybridization signal on J genome that is similar to the genome of Th . bessarabicum . Our results showed that the smallest alien chromosomes may represent a truncated chromosome and the repetitive sequence distribution might be similar in different chromosomes within the St genome. However, the repetitive sequence distributions are different within the Js genome, within a single chromosome, and among different genomes in Th . intermedium . Our results suggested that chromosome painting could be feasible in some plants and useful in detecting chromosome variation and repetitive sequence distribution in different genomes of polyploidy plants, which is helpful for understanding the evolution of different

  1. Cloning and chromosomal assignment of a human cDNA encoding a T cell- and natural killer cell-specific trypsin-like serine protease

    International Nuclear Information System (INIS)

    Gershenfeld, H.K.; Hershberger, R.J.; Shows, T.B.; Weissman, I.L.

    1988-01-01

    A cDNA clone encoding a human T cell- and natural killer cell-specific serine protease was obtained by screening a phage λgt10 cDNA library from phytohemagglutinin-stimulated human peripheral blood lymphocytes with the mouse Hanukah factor cDNA clone. In an RNA blot-hybridization analysis, this human Hanukah factor cDNA hybridized with a 1.3-kilobase band in allogeneic-stimulated cytotoxic T cells and the Jurkat cell line, but this transcript was not detectable in normal muscle, liver, tonsil, or thymus. By dot-blot hybridization, this cDNA hybridized with RNA from three cytolytic T-cell clones and three noncytolytic T-cell clones grown in vitro as well as with purified CD16 + natural killer cells and CD3 + , CD16 - T-cell large granular lymphocytes from peripheral blood lymphocytes (CD = cluster designation). The nucleotide sequence of this cDNA clone encodes a predicted serine protease of 262 amino acids. The active enzyme is 71% and 77% similar to the mouse sequence at the amino acid and DNA level, respectively. The human and mouse sequences conserve the active site residues of serine proteases--the trypsin-specific Asp-189 and all 10 cysteine residues. The gene for the human Hanukah factor serine protease is located on human chromosome 5. The authors propose that this trypsin-like serine protease may function as a common component necessary for lysis of target cells by cytotoxic T lymphocytes and natural killer cells

  2. Inter-chromosomal heterogeneity in the formation of radiation induced chromosomal aberrations

    International Nuclear Information System (INIS)

    Natarajan, A.T.; Vermeulen, S.; Boei, J.J.W.A.

    1997-01-01

    It is generally assumed that radiation induced chromosomal lesions are distributed randomly and repaired randomly among the genome. Recent studies using fluorescent in situ hybridization (FISH) and chromosome specific DNA libraries indicate that some chromosomes are more sensitive for radiation induced aberration formation than others. Chromosome No. 4 in human and chromosome No. 8 in Chinese hamster have been found to involve more in exchange aberrations than others, when calculated on the basis of their DNA content. Painting with arm specific chromosome libraries indicate that the frequencies of radiation induced intra-chromosome exchanges (i.e., between the arms of a chromosome, such as centric rings and inversions) are far in excess than one would expect on the basis of the frequencies of observed inter-chromosomal exchanges. The possible factors leading to the observed heterogeneity will be discussed

  3. Sexual antagonism and meiotic drive cause stable linkage disequilibrium and favour reduced recombination on the X chromosome.

    Science.gov (United States)

    Rydzewski, W T; Carioscia, S A; Liévano, G; Lynch, V D; Patten, M M

    2016-06-01

    Sexual antagonism and meiotic drive are sex-specific evolutionary forces with the potential to shape genomic architecture. Previous theory has found that pairing two sexually antagonistic loci or combining sexual antagonism with meiotic drive at linked autosomal loci augments genetic variation, produces stable linkage disequilibrium (LD) and favours reduced recombination. However, the influence of these two forces has not been examined on the X chromosome, which is thought to be enriched for sexual antagonism and meiotic drive. We investigate the evolution of the X chromosome under both sexual antagonism and meiotic drive with two models: in one, both loci experience sexual antagonism; in the other, we pair a meiotic drive locus with a sexually antagonistic locus. We find that LD arises between the two loci in both models, even when the two loci freely recombine in females and that driving haplotypes will be enriched for male-beneficial alleles, further skewing sex ratios in these populations. We introduce a new measure of LD, Dz', which accounts for population allele frequencies and is appropriate for instances where these are sex specific. Both models demonstrate that natural selection favours modifiers that reduce the recombination rate. These results inform observed patterns of congealment found on driving X chromosomes and have implications for patterns of natural variation and the evolution of recombination rates on the X chromosome. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

  4. AllelicImbalance: An R/ bioconductor package for detecting, managing, and visualizing allele expression imbalance data from RNA sequencing

    DEFF Research Database (Denmark)

    Gådin, Jesper R.; van't Hooft, Ferdinand M.; Eriksson, Per

    2015-01-01

    the possible biases. Results: We present AllelicImblance, a software program that is designed to detect, manage, and visualize allelic imbalances comprehensively. The purpose of this software is to allow users to pose genetic questions in any RNA sequencing experiment quickly, enhancing the general utility...... of RNA sequencing. The visualization features can reveal notable, non-trivial allelic imbalance behavior over specific regions, such as exons. Conclusions: The software provides a complete framework to perform allelic imbalance analyses of aligned RNA sequencing data, from detection to visualization...

  5. Allele coding in genomic evaluation

    Directory of Open Access Journals (Sweden)

    Christensen Ole F

    2011-06-01

    Full Text Available Abstract Background Genomic data are used in animal breeding to assist genetic evaluation. Several models to estimate genomic breeding values have been studied. In general, two approaches have been used. One approach estimates the marker effects first and then, genomic breeding values are obtained by summing marker effects. In the second approach, genomic breeding values are estimated directly using an equivalent model with a genomic relationship matrix. Allele coding is the method chosen to assign values to the regression coefficients in the statistical model. A common allele coding is zero for the homozygous genotype of the first allele, one for the heterozygote, and two for the homozygous genotype for the other allele. Another common allele coding changes these regression coefficients by subtracting a value from each marker such that the mean of regression coefficients is zero within each marker. We call this centered allele coding. This study considered effects of different allele coding methods on inference. Both marker-based and equivalent models were considered, and restricted maximum likelihood and Bayesian methods were used in inference. Results Theoretical derivations showed that parameter estimates and estimated marker effects in marker-based models are the same irrespective of the allele coding, provided that the model has a fixed general mean. For the equivalent models, the same results hold, even though different allele coding methods lead to different genomic relationship matrices. Calculated genomic breeding values are independent of allele coding when the estimate of the general mean is included into the values. Reliabilities of estimated genomic breeding values calculated using elements of the inverse of the coefficient matrix depend on the allele coding because different allele coding methods imply different models. Finally, allele coding affects the mixing of Markov chain Monte Carlo algorithms, with the centered coding being

  6. YY1 binding association with sex-biased transcription revealed through X-linked transcript levels and allelic binding analyses.

    Science.gov (United States)

    Chen, Chih-Yu; Shi, Wenqiang; Balaton, Bradley P; Matthews, Allison M; Li, Yifeng; Arenillas, David J; Mathelier, Anthony; Itoh, Masayoshi; Kawaji, Hideya; Lassmann, Timo; Hayashizaki, Yoshihide; Carninci, Piero; Forrest, Alistair R R; Brown, Carolyn J; Wasserman, Wyeth W

    2016-11-18

    Sex differences in susceptibility and progression have been reported in numerous diseases. Female cells have two copies of the X chromosome with X-chromosome inactivation imparting mono-allelic gene silencing for dosage compensation. However, a subset of genes, named escapees, escape silencing and are transcribed bi-allelically resulting in sexual dimorphism. Here we conducted in silico analyses of the sexes using human datasets to gain perspectives into such regulation. We identified transcription start sites of escapees (escTSSs) based on higher transcription levels in female cells using FANTOM5 CAGE data. Significant over-representations of YY1 transcription factor binding motif and ChIP-seq peaks around escTSSs highlighted its positive association with escapees. Furthermore, YY1 occupancy is significantly biased towards the inactive X (Xi) at long non-coding RNA loci that are frequent contacts of Xi-specific superloops. Our study suggests a role for YY1 in transcriptional activity on Xi in general through sequence-specific binding, and its involvement at superloop anchors.

  7. Allele coding in genomic evaluation

    DEFF Research Database (Denmark)

    Standen, Ismo; Christensen, Ole Fredslund

    2011-01-01

    Genomic data are used in animal breeding to assist genetic evaluation. Several models to estimate genomic breeding values have been studied. In general, two approaches have been used. One approach estimates the marker effects first and then, genomic breeding values are obtained by summing marker...... effects. In the second approach, genomic breeding values are estimated directly using an equivalent model with a genomic relationship matrix. Allele coding is the method chosen to assign values to the regression coefficients in the statistical model. A common allele coding is zero for the homozygous...... genotype of the first allele, one for the heterozygote, and two for the homozygous genotype for the other allele. Another common allele coding changes these regression coefficients by subtracting a value from each marker such that the mean of regression coefficients is zero within each marker. We call...

  8. An anther- and petal-specific gene SlMF1 is a multicopy gene with homologous sequences on sex chromosomes

    Czech Academy of Sciences Publication Activity Database

    Matsunaga, S.; Lebel-Hardenack, S.; Kejnovský, Eduard; Vyskot, Boris; Grant, Sarah R.; Kawano, S.

    2005-01-01

    Roč. 80, - (2005), s. 395-401 ISSN 1341-7568 R&D Projects: GA ČR(CZ) GA204/05/2097 Institutional research plan: CEZ:AV0Z50040507 Keywords : dioecious plant * male flower * sex chromosomes Subject RIV: BO - Biophysics Impact factor: 1.081, year: 2005

  9. Next-generation sequencing of flow-sorted wheat chromosome 5D reveals lineage-specific translocations and widespread gene duplications

    Czech Academy of Sciences Publication Activity Database

    Lucas, S. J.; Akpinar, B. A.; Šimková, Hana; Kubaláková, Marie; Doležel, Jaroslav; Budak, H.

    2014-01-01

    Roč. 15, DEC 9 2014 (2014) ISSN 1471-2164 R&D Projects: GA ČR GBP501/12/G090 Institutional support: RVO:61389030 Keywords : Wheat genome * Chromosome sorting * Triticum aestivum Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.986, year: 2014

  10. Cytological and molecular relationships between Larix decidua, L. leptolepis and Larix x eurolepis: identification of species-specific Chromosoms and synchronization of mitotic cells.

    Science.gov (United States)

    Nkongolo, K K; Klimaszewska, K

    1995-05-01

    The effects of different concentrations of hydroxyurea (HU) and aphidicolin (APH) on the mitotic index (MI) were compared in cells of embryogenic cultures of Larix decidua, L. leptolepis, and L. decidua x L. leptolepis (Larix x eurolepis). The highest enhancement of the MI was obtained with HU at 1.25 mM and 0.6% colchicine. In general the MI decreased with an increase of HU or APH concentration (over 1.25 mM for HU and 5 μM for APH). Detailed karyotype analyses were made on the somatic complement of L. decidua, L. leptolepis, and their hybrid. These karyotypes were asymmetrical and advanced, with the smaller chromosomes being more submedian than the larger ones. The topography of chromosome 7 of L. decidua and chromosome 9 of L. leptolepis was found to be the most significant cytotaxonomic characteristic in differentiating these two species. Cytological data indicate that Japanese larch (L. leptolepis) is phylogenetically closer to European larch (L. decidua) than the Siberian larch group (L. sibirica and L. sukaczewii). Chromosomes with unusually long kinetochores were found in both species and the hybrid. Hyperploid cells (2n = 25) were observed in the hybrid (Larix x eurolepis) material analyzed. A genomic L. decidua probe hybridized strongly to dots of DNA from L. leptolepis indicating that there is high sequence homology between these two species.

  11. RHD alleles in the Tunisian population

    Science.gov (United States)

    Ouchari, Mouna; Jemni-Yaacoub, Saloua; Chakroun, Taher; Abdelkefi, Saida; Houissa, Batoul; Hmida, Slama

    2013-01-01

    Background: A comprehensive survey of RHD alleles in Tunisia population was lacking. The aim of this study was to use a multiplex RHD typing assay for simultaneous detection of partial D especially with RHD/RHCE deoxyribonucleic acid (DNA) sequence exchange mechanism and some weak D alleles. Materials and Methods: Six RHD specific primer sets were designed to amplify RHD exons 3, 4, 5, 6, 7 and 9. DNA from 2000 blood donors (1777 D+ and 223 D-) from several regions was selected for RHD genotyping using a PCR multiplex assay. Further molecular investigations were done to characterize the RHD variants that were identified by the PCR multiplex assay. Results: In the 1777 D+ samples, only 10 individuals showed the absence of amplification of exons 4 and 5 that were subsequently identified by PCR-SSP as weak D type 4 variants. No hybrid allele was detected. In the 223 D-, RHD amplification of some exons was observed only in 5 samples: 4 individuals expressed only RHD exon 9, and one subject lacking exons 4 and 5. These samples were then screened by PCR-SSPs on d(C) ces and weak D type 4, respectively. Conclusion: The weak D type 4 appears to be the most common D variant allele. We have not found any partial D variant. Findings also indicated that RHD gene deletion is the most prevalent cause of the D- phenotype in the Tunisian population. PMID:24014941

  12. Sex-chromosome differentiation parallels postglacial range expansion in European tree frogs (Hyla arborea).

    Science.gov (United States)

    Dufresnes, Christophe; Bertholet, Youna; Wassef, Jérôme; Ghali, Karim; Savary, Romain; Pasteur, Baptiste; Brelsford, Alan; Rozenblut-Kościsty, Beata; Ogielska, Maria; Stöck, Matthias; Perrin, Nicolas

    2014-12-01

    Occasional XY recombination is a proposed explanation for the sex-chromosome homomorphy in European tree frogs. Numerous laboratory crosses, however, failed to detect any event of male recombination, and a detailed survey of NW-European Hyla arborea populations identified male-specific alleles at sex-linked loci, pointing to the absence of XY recombination in their recent history. Here, we address this paradox in a phylogeographic framework by genotyping sex-linked microsatellite markers in populations and sibships from the entire species range. Contrasting with postglacial populations of NW Europe, which display complete absence of XY recombination and strong sex-chromosome differentiation, refugial populations of the southern Balkans and Adriatic coast show limited XY recombination and large overlaps in allele frequencies. Geographically and historically intermediate populations of the Pannonian Basin show intermediate patterns of XY differentiation. Even in populations where X and Y occasionally recombine, the genetic diversity of Y haplotypes is reduced below the levels expected from the fourfold drop in copy numbers. This study is the first in which X and Y haplotypes could be phased over the distribution range in a species with homomorphic sex chromosomes; it shows that XY-recombination patterns may differ strikingly between conspecific populations, and that recombination arrest may evolve rapidly (<5000 generations). © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  13. Tri-allelic SNP markers enable analysis of mixed and degraded DNA samples.

    Science.gov (United States)

    Westen, Antoinette A; Matai, Anuska S; Laros, Jeroen F J; Meiland, Hugo C; Jasper, Mandy; de Leeuw, Wiljo J F; de Knijff, Peter; Sijen, Titia

    2009-09-01

    For the analysis of degraded DNA in disaster victim identification (DVI) and criminal investigations, single nucleotide polymorphisms (SNPs) have been recognized as promising markers mainly because they can be analyzed in short sized amplicons. Most SNPs are bi-allelic and are thereby ineffective to detect mixtures, which may lead to incorrect genotyping. We developed an algorithm to find non-binary (i.e. tri-allelic or tetra-allelic) SNPs in the NCBI dbSNP database. We selected 31 potential tri-allelic SNPs with a minor allele frequency of at least 10%. The tri-allelic nature was confirmed for 15 SNPs residing on 14 different chromosomes. Multiplex SNaPshot assays were developed, and the allele frequencies of 16 SNPs were determined among 153 Dutch and 111 Netherlands Antilles reference samples. Using these multiplex SNP assays, the presence of a mixture of two DNA samples in a ratio up to 1:8 could be recognized reliably. Furthermore, we compared the genotyping efficiency of the tri-allelic SNP markers and short tandem repeat (STR) markers by analyzing artificially degraded DNA and DNA from 30 approximately 500-year-old bone and molar samples. In both types of degraded DNA samples, the larger sized STR amplicons failed to amplify whereas the tri-allelic SNP markers still provided valuable information. In conclusion, tri-allelic SNP markers are suited for the analysis of degraded DNA and enable the detection of a second DNA source in a sample.

  14. Detection of the V1016G mutation in the voltage-gated sodium channel gene of Aedes aegypti (Diptera: Culicidae) by allele-specific PCR assay, and its distribution and effect on deltamethrin resistance in Thailand.

    Science.gov (United States)

    Stenhouse, Steven A; Plernsub, Suriya; Yanola, Jintana; Lumjuan, Nongkran; Dantrakool, Anchalee; Choochote, Wej; Somboon, Pradya

    2013-08-30

    Resistance to pyrethroid insecticides is widespread among populations of Aedes aegypti, the main vector for the dengue virus. Several different point mutations within the voltage-gated sodium channel (VGSC) gene contribute to such resistance. A mutation at position 1016 in domain II, segment 6 of the VGSC gene in Ae. aegypti leads to a valine to glycine substitution (V1016G) that confers resistance to deltamethrin. This study developed and utilized an allele-specific PCR (AS-PCR) assay that could be used to detect the V1016G mutation. The assay was validated against a number of sequenced DNA samples of known genotype and was determined to be in complete agreement. Larvae and pupae were collected from various localities throughout Thailand. Samples were reared to adulthood and their resistance status against deltamethrin was determined by standard WHO susceptibility bioassays. Deltamethrin-resistant and susceptible insects were then genotyped for the V1016G mutation. Additionally, some samples were genotyped for a second mutation at position 1534 in domain III (F1534C) which is also known to confer pyrethroid resistance. The bioassay results revealed an overall mortality of 77.6%. Homozygous 1016G individuals survived at higher rates than either heterozygous or wild-type (1016 V) mosquitoes. The 1016G mutation was significantly and positively associated with deltamethrin resistance and was widely distributed throughout Thailand. Interestingly, wild-type 1016 V mosquitoes tested were homozygous for the 1534C mutation, and all heterozygous mosquitoes were also heterozygous for 1534C. Mutant homozygous (G/G) mosquitoes expressed the wild-type (F/F) at position 1534. However, the presence of the 1534C mutation was not associated with deltamethrin resistance. Our bioassay results indicate that all populations sampled display some degree of resistance to deltamethrin. Homozygous 1016G mosquitoes were far likelier to survive such exposure. However, resistance in some

  15. Comparison of 454 Ultra-Deep Sequencing and Allele-Specific Real-Time PCR with Regard to the Detection of Emerging Drug-Resistant Minor HIV-1 Variants after Antiretroviral Prophylaxis for Vertical Transmission.

    Directory of Open Access Journals (Sweden)

    Andrea Hauser

    Full Text Available Pregnant HIV-infected women were screened for the development of HIV-1 drug resistance after implementation of a triple-antiretroviral transmission prophylaxis as recommended by the WHO in 2006. The study offered the opportunity to compare amplicon-based 454 ultra-deep sequencing (UDS and allele-specific real-time PCR (ASPCR for the detection of drug-resistant minor variants in the HIV-1 reverse transcriptase (RT.Plasma samples from 34 Tanzanian women were previously analysed by ASPCR for key resistance mutations in the viral RT selected by AZT, 3TC, and NVP (K70R, K103N, Y181C, M184V, T215Y/F. In this study, the RT region of the same samples was investigated by amplicon-based UDS for resistance mutations using the 454 GS FLX System.Drug-resistant HIV-variants were identified in 69% (20/29 of women by UDS and in 45% (13/29 by ASPCR. The absolute number of resistance mutations identified by UDS was twice that identified by ASPCR (45 vs 24. By UDS 14 of 24 ASPCR-detected resistance mutations were identified at the same position. The overall concordance between UDS and ASPCR was 61.0% (25/41. The proportions of variants quantified by UDS were approximately 2-3 times lower than by ASPCR. Amplicon generation from samples with viral loads below 20,000 copies/ml failed more frequently by UDS compared to ASPCR (limit of detection = 650 copies/ml, resulting in missing or insufficient sequence coverage.Both methods can provide useful information about drug-resistant minor HIV-1 variants. ASPCR has a higher sensitivity than UDS, but is restricted to single resistance mutations. In contrast, UDS is limited by its requirement for high viral loads to achieve sufficient sequence coverage, but the sequence information reveals the complete resistance patterns within the genomic region analysed. Improvements to the UDS limit of detection are in progress, and UDS could then facilitate monitoring of drug-resistant minor variants in the HIV-1 quasispecies.

  16. Mitotic chromosome condensation in vertebrates

    International Nuclear Information System (INIS)

    Vagnarelli, Paola

    2012-01-01

    Work from several laboratories over the past 10–15 years has revealed that, within the interphase nucleus, chromosomes are organized into spatially distinct territories [T. Cremer, C. Cremer, Chromosome territories, nuclear architecture and gene regulation in mammalian cells, Nat. Rev. Genet. 2 (2001) 292–301 and T. Cremer, M. Cremer, S. Dietzel, S. Muller, I. Solovei, S. Fakan, Chromosome territories—a functional nuclear landscape, Curr. Opin. Cell Biol. 18 (2006) 307–316]. The overall compaction level and intranuclear location varies as a function of gene density for both entire chromosomes [J.A. Croft, J.M. Bridger, S. Boyle, P. Perry, P. Teague,W.A. Bickmore, Differences in the localization and morphology of chromosomes in the human nucleus, J. Cell Biol. 145 (1999) 1119–1131] and specific chromosomal regions [N.L. Mahy, P.E. Perry, S. Gilchrist, R.A. Baldock, W.A. Bickmore, Spatial organization of active and inactive genes and noncoding DNA within chromosome territories, J. Cell Biol. 157 (2002) 579–589] (Fig. 1A, A'). In prophase, when cyclin B activity reaches a high threshold, chromosome condensation occurs followed by Nuclear Envelope Breakdown (NEB) [1]. At this point vertebrate chromosomes appear as compact structures harboring an attachment point for the spindle microtubules physically recognizable as a primary constriction where the two sister chromatids are held together. The transition from an unshaped interphase chromosome to the highly structured mitotic chromosome (compare Figs. 1A and B) has fascinated researchers for several decades now; however a definite picture of how this process is achieved and regulated is not yet in our hands and it will require more investigation to comprehend the complete process. From a biochemical point of view a vertebrate mitotic chromosomes is composed of DNA, histone proteins (60%) and non-histone proteins (40%) [6]. I will discuss below what is known to date on the contribution of these two different

  17. Mitotic chromosome condensation in vertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Vagnarelli, Paola, E-mail: P.Vagnarelli@ed.ac.uk

    2012-07-15

    Work from several laboratories over the past 10-15 years has revealed that, within the interphase nucleus, chromosomes are organized into spatially distinct territories [T. Cremer, C. Cremer, Chromosome territories, nuclear architecture and gene regulation in mammalian cells, Nat. Rev. Genet. 2 (2001) 292-301 and T. Cremer, M. Cremer, S. Dietzel, S. Muller, I. Solovei, S. Fakan, Chromosome territories-a functional nuclear landscape, Curr. Opin. Cell Biol. 18 (2006) 307-316]. The overall compaction level and intranuclear location varies as a function of gene density for both entire chromosomes [J.A. Croft, J.M. Bridger, S. Boyle, P. Perry, P. Teague,W.A. Bickmore, Differences in the localization and morphology of chromosomes in the human nucleus, J. Cell Biol. 145 (1999) 1119-1131] and specific chromosomal regions [N.L. Mahy, P.E. Perry, S. Gilchrist, R.A. Baldock, W.A. Bickmore, Spatial organization of active and inactive genes and noncoding DNA within chromosome territories, J. Cell Biol. 157 (2002) 579-589] (Fig. 1A, A'). In prophase, when cyclin B activity reaches a high threshold, chromosome condensation occurs followed by Nuclear Envelope Breakdown (NEB) [1]. At this point vertebrate chromosomes appear as compact structures harboring an attachment point for the spindle microtubules physically recognizable as a primary constriction where the two sister chromatids are held together. The transition from an unshaped interphase chromosome to the highly structured mitotic chromosome (compare Figs. 1A and B) has fascinated researchers for several decades now; however a definite picture of how this process is achieved and regulated is not yet in our hands and it will require more investigation to comprehend the complete process. From a biochemical point of view a vertebrate mitotic chromosomes is composed of DNA, histone proteins (60%) and non-histone proteins (40%) [6]. I will discuss below what is known to date on the contribution of these two different classes

  18. Assigning breed origin to alleles in crossbred animals.

    Science.gov (United States)

    Vandenplas, Jérémie; Calus, Mario P L; Sevillano, Claudia A; Windig, Jack J; Bastiaansen, John W M

    2016-08-22

    For some species, animal production systems are based on the use of crossbreeding to take advantage of the increased performance of crossbred compared to purebred animals. Effects of single nucleotide polymorphisms (SNPs) may differ between purebred and crossbred animals for several reasons: (1) differences in linkage disequilibrium between SNP alleles and a quantitative trait locus; (2) differences in genetic backgrounds (e.g., dominance and epistatic interactions); and (3) differences in environmental conditions, which result in genotype-by-environment interactions. Thus, SNP effects may be breed-specific, which has led to the development of genomic evaluations for crossbred performance that take such effects into account. However, to estimate breed-specific effects, it is necessary to know breed origin of alleles in crossbred animals. Therefore, our aim was to develop an approach for assigning breed origin to alleles of crossbred animals (termed BOA) without information on pedigree and to study its accuracy by considering various factors, including distance between breeds. The BOA approach consists of: (1) phasing genotypes of purebred and crossbred animals; (2) assigning breed origin to phased haplotypes; and (3) assigning breed origin to alleles of crossbred animals based on a library of assigned haplotypes, the breed composition of crossbred animals, and their SNP genotypes. The accuracy of allele assignments was determined for simulated datasets that include crosses between closely-related, distantly-related and unrelated breeds. Across these scenarios, the percentage of alleles of a crossbred animal that were correctly assigned to their breed origin was greater than 90 %, and increased with increasing distance between breeds, while the percentage of incorrectly assigned alleles was always less than 2 %. For the remaining alleles, i.e. 0 to 10 % of all alleles of a crossbred animal, breed origin could not be assigned. The BOA approach accurately assigns

  19. Flow cytogenetics and chromosome sorting.

    Science.gov (United States)

    Cram, L S

    1990-06-01

    This review of flow cytogenetics and chromosome sorting provides an overview of general information in the field and describes recent developments in more detail. From the early developments of chromosome analysis involving single parameter or one color analysis to the latest developments in slit scanning of single chromosomes in a flow stream, the field has progressed rapidly and most importantly has served as an important enabling technology for the human genome project. Technological innovations that advanced flow cytogenetics are described and referenced. Applications in basic cell biology, molecular biology, and clinical investigations are presented. The necessary characteristics for large number chromosome sorting are highlighted. References to recent review articles are provided as a starting point for locating individual references that provide more detail. Specific references are provided for recent developments.

  20. Effects of chromosomal rearrangements on the zeste-white interaction in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Smolik-Utlaut, S.M.; Gelbart, W.M.

    1987-01-01

    Three gene systems have been shown to exhibit proximity-dependent phenotypes in Drosophila melanogaster; bithorax (BX-C), decapentaplegic (DPP-C) and white (w). In structurally homozygous genotypes, specific allelic combinations at these loci exhibit one phenotype, while in certain rearrangement heterozygotes the same allelic combinations exhibit dramatically different phenotypes. The genetic properties of the proximity-dependent allelic complementation (termed transvection effects) at the BX-C and DPP-C, are quite similar. As determined by cytogenetic analysis of transvection-disrupting rearrangements, the critical regions for the BX-C and DDP-C transvection effects extend proximally from these loci for several hundred polytene chromosome bands. The interaction between the zeste and white loci appears to depend upon the proximity of the two w + alleles. By use of insertional duplications, displacement of w + homologues has been shown to interfere with the zeste-white interaction. In this report, the authors investigate the basis for the difference in the size of the BX-C and DPP-C critical regions from that of white using a 137 Cs-mutagenesis procedure. The authors test and eliminate the possibility that the difference is due to evidence strongly suggests that the zeste-white interaction is, at the phenotypic level, much less sensitive to displacement of the homologous genes than is transvection at either the BX-C or DPP-C. Given these results, they suggest that the zeste-white interaction and transvection are two different proximity-dependent phenomena

  1. Establishment of a 10-Plex Quantitative Fluorescent-PCR Assay for rapid diagnosis of sex chromosome aneuploidies.

    Directory of Open Access Journals (Sweden)

    Xingmei Xie

    Full Text Available Sex chromosome aneuploidies occur commonly in the general population, with an incidence of 1 in 400 newborns. However, no tests specifically targeting sex chromosomes have been carried out in prenatal diagnosis or newborn screening, resulting in late recognition of these diseases. In this study, a rapid diagnostic method for sex chromosome aneuploidies was established using Quantitative Fluorescent-PCR (QF-PCR. Ten markers were included in one multiplex QF-PCR assay, including two sex determination genes (AMXY and SRY, five X-linked short tandem repeats (STRs; DXS1053, DXS981, DXS6809, DXS1187, and DXS8377, one X/Y-common STR (X22, and two autosomal STRs (D13S305 and D21S11. Retrospective tests of 70 cases with known cytogenetic results indicated that the 10-plex QF-PCR assay could well determine sex chromosome copy numbers by both allelic peak numbers and a sex chromosome dosage calculation with the autosomal STRs as internal controls. Prospective comparison with cytogenetic karyotyping on 534 cases confirmed that the 10-plex QF-PCR assay could be well employed for sex chromosome aneuploidy diagnosis in at least the Chinese Han population. This is the first QF-PCR test for the diagnosis of sex chromosome aneuploidies in the Chinese population. This test is superior to previous designs by including up to 8 sex-linked markers covering different parts of sex chromosomes as well as employing internal controls for copy number dosage calculation in a single PCR reaction. Due to simple technique and data analysis, as well as easy implementation within routine clinical services, this method is of great clinical application value and could be widely applied.

  2. Combined fluorescent-chromogenic in situ hybridization for identification and laser microdissection of interphase chromosomes.

    Directory of Open Access Journals (Sweden)

    Nerea Paz

    Full Text Available Chromosome territories constitute the most conspicuous feature of nuclear architecture, and they exhibit non-random distribution patterns in the interphase nucleus. We observed that in cell nuclei from humans with Down Syndrome two chromosomes 21 frequently localize proximal to one another and distant from the third chromosome. To systematically investigate whether the proximally positioned chromosomes were always the same in all cells, we developed an approach consisting of sequential FISH and CISH combined with laser-microdissection of chromosomes from the interphase nucleus and followed by subsequent chromosome identification by microsatellite allele genotyping. This approach identified proximally positioned chromosomes from cultured cells, and the analysis showed that the identity of the chromosomes proximally positioned varies. However, the data suggest that there may be a tendency of the same chromosomes to be positioned close to each other in the interphase nucleus of trisomic cells. The protocol described here represents a powerful new method for genome analysis.

  3. Frequent gene conversion events between the X and Y homologous chromosomal regions in primates

    Directory of Open Access Journals (Sweden)

    Hirai Hirohisa

    2010-07-01

    Full Text Available Abstract Background Mammalian sex-chromosomes originated from a pair of autosomes. A step-wise cessation of recombination is necessary for the proper maintenance of sex-determination and, consequently, generates a four strata structure on the X chromosome. Each stratum shows a specific per-site nucleotide sequence difference (p-distance between the X and Y chromosomes, depending on the time of recombination arrest. Stratum 4 covers the distal half of the human X chromosome short arm and the p-distance of the stratum is ~10%, on average. However, a 100-kb region, which includes KALX and VCX, in the middle of stratum 4 shows a significantly lower p-distance (1-5%, suggesting frequent sequence exchanges or gene conversions between the X and Y chromosomes in humans. To examine the evolutionary mechanism for this low p-distance region, sequences of a corresponding region including KALX/Y from seven species of non-human primates were analyzed. Results Phylogenetic analysis of this low p-distance region in humans and non-human primate species revealed that gene conversion like events have taken place at least ten times after the divergence of New World monkeys and Catarrhini (i.e., Old World monkeys and hominoids. A KALY-converted KALX allele in white-handed gibbons also suggests a possible recent gene conversion between the X and Y chromosomes. In these primate sequences, the proximal boundary of this low p-distance region is located in a LINE element shared between the X and Y chromosomes, suggesting the involvement of this element in frequent gene conversions. Together with a palindrome on the Y chromosome, a segmental palindrome structure on the X chromosome at the distal boundary near VCX, in humans and chimpanzees, may mediate frequent sequence exchanges between X and Y chromosomes. Conclusion Gene conversion events between the X and Y homologous regions have been suggested, mainly in humans. Here, we found frequent gene conversions in the

  4. A novel resource for genomics of Triticeae: BAC library specific for the short arm of rye (Secale cereale L.) chromosome 1R (1RS)

    Czech Academy of Sciences Publication Activity Database

    Šimková, Hana; Šafář, Jan; Suchánková, Pavla; Kovářová, Pavlína; Bartoš, Jan; Kubaláková, Marie; Janda, Jaroslav; Čihalíková, Jarmila; Mago, R.; Lelley, T.; Doležel, Jaroslav

    2008-01-01

    Roč. 9, č. 237 (2008), s. 101-109 ISSN 1471-2164 R&D Projects: GA ČR GA521/04/0607; GA ČR GP521/05/P257; GA ČR GD521/05/H013; GA MŠk(CZ) LC06004 Institutional research plan: CEZ:AV0Z50380511 Keywords : flow cytometry * flow-sorted chromosomes * BAC library Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.926, year: 2008

  5. Mitotic chromosome structure

    International Nuclear Information System (INIS)

    Heermann, Dieter W.

    2012-01-01

    Mounting evidence is compiling linking the physical organizational structure of chromosomes and the nuclear structure to biological function. At the base of the physical organizational structure of both is the concept of loop formation. This implies that physical proximity within chromosomes is provided for otherwise distal genomic regions and thus hierarchically organizing the chromosomes. Together with entropy many experimental observations can be explained with these two concepts. Among the observations that can be explained are the measured physical extent of the chromosomes, their shape, mechanical behavior, the segregation into territories (chromosomal and territories within chromosomes), the results from chromosome conformation capture experiments, as well as linking gene expression to structural organization.

  6. Mitotic chromosome structure

    Energy Technology Data Exchange (ETDEWEB)

    Heermann, Dieter W., E-mail: heermann@tphys.uni-heidelberg.de

    2012-07-15

    Mounting evidence is compiling linking the physical organizational structure of chromosomes and the nuclear structure to biological function. At the base of the physical organizational structure of both is the concept of loop formation. This implies that physical proximity within chromosomes is provided for otherwise distal genomic regions and thus hierarchically organizing the chromosomes. Together with entropy many experimental observations can be explained with these two concepts. Among the observations that can be explained are the measured physical extent of the chromosomes, their shape, mechanical behavior, the segregation into territories (chromosomal and territories within chromosomes), the results from chromosome conformation capture experiments, as well as linking gene expression to structural organization.

  7. Diversity Outbred Mice at 21: Maintaining Allelic Variation in the Face of Selection

    Directory of Open Access Journals (Sweden)

    Elissa J. Chesler

    2016-12-01

    Full Text Available Multi-parent populations (MPPs capture and maintain the genetic diversity from multiple inbred founder strains to provide a resource for high-resolution genetic mapping through the accumulation of recombination events over many generations. Breeding designs that maintain a large effective population size with randomized assignment of breeders at each generation can minimize the impact of selection, inbreeding, and genetic drift on allele frequencies. Small deviations from expected allele frequencies will have little effect on the power and precision of genetic analysis, but a major distortion could result in reduced power and loss of important functional alleles. We detected strong transmission ratio distortion in the Diversity Outbred (DO mouse population on chromosome 2, caused by meiotic drive favoring transmission of the WSB/EiJ allele at the R2d2 locus. The distorted region harbors thousands of polymorphisms derived from the seven non-WSB founder strains and many of these would be lost if the sweep was allowed to continue. To ensure the utility of the DO population to study genetic variation on chromosome 2, we performed an artificial selection against WSB/EiJ alleles at the R2d2 locus. Here, we report that we have purged the WSB/EiJ allele from the drive locus while preserving WSB/EiJ alleles in the flanking regions. We observed minimal disruption to allele frequencies across the rest of the autosomal genome. However, there was a shift in haplotype frequencies of the mitochondrial genome and an increase in the rate of an unusual sex chromosome aneuploidy. The DO population has been restored to genome-wide utility for genetic analysis, but our experience underscores that vigilant monitoring of similar genetic resource populations is needed to ensure their long-term utility.

  8. Ancestral QTL alleles from wild emmer wheat improve drought resistance and productivity in modern wheat cultivars

    Directory of Open Access Journals (Sweden)

    Lianne eMerchuk-Ovnat

    2016-04-01

    Full Text Available Wild emmer wheat (Triticum turgidum ssp. dicoccoides is considered a promising source for improving stress resistances in domesticated wheat. Here we explored the potential of selected quantitative trait loci (QTLs from wild emmer wheat, introgressed via marker-assisted selection, to enhance drought resistance in elite durum (T. turgidum ssp. durum and bread (T. aestivum wheat cultivars. The resultant near-isogenic lines (BC3F3 and BC3F4 were genotyped using SNP array to confirm the introgressed genomic regions and evaluated in two consecutive years under well-watered (690–710 mm and water-limited (290–320 mm conditions. Three of the introgressed QTLs were successfully validated, two in the background of durum wheat cv. Uzan (on chromosomes 1BL and 2BS, and one in the background of bread wheat cvs. Bar Nir and Zahir (chromosome 7AS. In most cases, the QTL x environment interaction was validated in terms of improved grain yield and biomass - specifically under drought (7AS QTL in cv. Bar Nir background, under both treatments (2BS QTL, and a greater stability across treatments (1BL QTL. The results provide a first demonstration that introgression of wild emmer QTL alleles can enhance productivity and yield stability across environments in domesticated wheat, thereby enriching the modern gene pool with essential diversity for the improvement of drought resistance.

  9. Allele frequency present within the DYS635, DYS437, DYS448 ...

    African Journals Online (AJOL)

    Ejiro

    2015-03-11

    Mar 11, 2015 ... institute and courts of law. Key words: Allele ... individual identification and relatedness testing polymor- phic (Yamamoto et al. ... haplogroup an individual matches, STR analysis typically provides a person haplotype. Most tests on the Y chromosome examine between 12 and 67 STR markers. (Jobling et al.

  10. The BTNL2 A allele variant is frequent in Danish patients with sarcoidosis

    DEFF Research Database (Denmark)

    Milman, Nils; Svendsen, Claus Bo; Nielsen, Finn Cilius

    2011-01-01

    The butyrophilin-like 2 (BTNL2) gene is located on chromosome 6p21.3 close to the HLA-class II genes. An association has been reported between sarcoidosis and a single nucleotide polymorphism in BTNL2, rs2076530, also termed the A allele....

  11. Chromosomal instability can be induced by the formation of breakage-prone chromosome rearrangement junctions

    International Nuclear Information System (INIS)

    Allen, R.N.; Ritter, L.; Moore, S.R.; Grosovsky, A.J.

    2003-01-01

    Full text: Studies in our lab have led to the hypothesis that chromosomal rearrangements can generate novel breakage-prone sites, resulting in chromosomal instability acting predominantly in cis. For example, specific breakage of large blocks of centromeric region heterochromatin on chromosome 16q by treatment with 2,6-diaminopurine (DAP) is associated with repeated rearrangement of chromosome 16q during outgrowth of DAP-treated clones, thereby establishing a link between the initial site of damage and the occurrence of persistent chromosomal instability. Similarly, karyotypic analysis of gamma ray induced instability demonstrated that chromosomal rearrangements in sub-clones were significantly clustered near the site of previously identified chromosomal rearrangement junctions in unstable parental clones. This study investigates the hypothesis that integration of transfected sequences into host chromosomes could create breakage-prone junction regions and persistent genomic instability without exposure to DNA-damage agents. These junctions may mimic the unstable chromosomal rearrangements induced by DAP or radiation, and thus provide a test of the broader hypothesis that instability can to some extent be attributed to the formation of novel chromosomal breakage hot spots. These experiments were performed using human-hamster hybrid AL cells containing a single human chromosome 11, which was used to monitor instability in a chromosomal painting assay. AL cells were transfected with a 2.5 Kb fragment containing multiple copies of the 180 bp human alpha heterochromatic repeat, which resulted in chromosomal instability in 41% of the transfected clones. Parallel exposure to gamma-radiation resulted in a similar level of chromosomal instability, although control transfections with plasmid alone did not lead to karyotypic instability. Chromosomal instability induced by integration of alpha heterochromatic repeats was also frequently associated with delayed reproductive

  12. Polymorphic haplotypes on R408BW PKU and normal PAH chromosomes in Quebec and European populations

    Energy Technology Data Exchange (ETDEWEB)

    Byck, S.; Morgan, K.; Scriver, C.R. [McGill Univ., Montreal (Canada)] [and others

    1994-09-01

    The R408W mutation in the phenylalanine hydroxylase gene (PAH) is associated with haplotype 2.3 (RFLP haplotype 2, VNTR 3 of the HindIII system) in most European populations. Another chromosome, first observed in Quebec and then in northwest Europe, carries R408W on haplotype 1.8. The occurrence of the R408W mutation on two different PKU chromosomes could be the result of intragenic recombination, recurrent mutation or gene conversion. In this study, we analyzed both normal and R408W chromosomes carrying 1.8 and 2.3 haplotypes in Quebec and European populations; we used the TCTA{sub (n)} short tandem repeat sequence (STR) at the 5{prime} end of the PAH gene and the HindIII VNTR system at the 3{prime} end of the PAH gene to characterize chromosomes. Fourteen of sixteen R408W chromosomes from {open_quotes}Celtic{close_quotes} families in Quebec and the United Kingdom (UK) harbor a 244 bp STR allele; the remaining two chromosomes, carry a 240 bp or 248bp STR allele. Normal chromosomes (n=18) carry the 240 bp STR allele. R408W chromosomes are different from mutant H1.8 chromosomes; mutant H2.3 carries the 240 bp STR allele (14 of 16 chromosomes) or the 236 allele (2 of 16 chromosomes). The HindIII VNTR comprises variable numbers of 30 bp repeats (cassettes); the repeats also vary in nucleotide sequence. Variation clusters toward the 3{prime} end of cassettes and VNTRs. VNTR 3 alleles on normal H2 (n=9) and mutant R408W H2 (n=19) chromosomes were identical. VNTR 8 alleles on normal H1 chromosomes (n=9) and on R408W H1 chromosomes (n=15) differ by 1 bp substitution near the 3{prime} end of the 6th cassette. In summary, the mutant H1.8 chromosome harboring the R408W mutation has unique features at both the 5{prime} and 3{prime} end of the gene that distinguish it from the mutant H2.3 and normal H1.8 and H2.3 counterparts. The explanation for the occurrence of R408W on two different PAH haplotypes is recurrent mutation affecting the CpG dinucleotide in PAH codon 408.

  13. Microdissection and chromosome painting of the alien chromosome in an addition line of wheat--Thinopyrum intermedium.

    Science.gov (United States)

    Deng, Chuanliang; Bai, Lili; Fu, Shulan; Yin, Weibo; Zhang, Yingxin; Chen, Yuhong; Wang, Richard R-C; Zhang, Xiangqi; Han, Fangpu; Hu, Zanmin

    2013-01-01

    In this study, chromosome painting was developed and used to identify alien chromosomes in TAi-27, a wheat--Thinopyrum intermedium addition line, and the chromosomes of the three different genomes of Th. Intermedium. The smallest alien chromosome of TAi-27 was microdissected and its DNA amplified by DOP-PCR was used as a probe to hybridize with metaphase chromosomes of TAi-27 and Th. intermedium. Results showed that hybridization signals were observed in all regions of a pair of the smallest alien chromosomes and the pericentromeric area of another pair of alien chromosomes in TAi-27, indicating that the probe from microdissected chromosome is species specific. In Th. intermedium, 14 chromosomes had wide and strong hybridization signals distributed mainly on the pericentromere area and 9 chromosomes with narrow and weak signals on the pericentromere area. The remaining chromosomes displayed a very weak or no signal. Sequential FISH/GISH on Th. intermedium chromosomes using the DNAs of microdissected chromosome, Pseudoroegneria spicata (St genome) and pDbH12 (a J(s) genome specific probe) as the probes indicated that the microdissected chromosome belonged to the St genome, three genomes (J(s) , J and St) in Th. intermedium could be distinguished, in which there is no hybridization signal on J genome that is similar to the genome of Th. bessarabicum. Our results showed that the smallest alien chromosomes may represent a truncated chromosome and the repetitive sequence distribution might be similar in different chromosomes within the St genome. However, the repetitive sequence distributions are different within the J(s) genome, within a single chromosome, and among different genomes in Th. intermedium. Our results suggested that chromosome painting could be feasible in some plants and useful in detecting chromosome variation and repetitive sequence distribution in different genomes of polyploidy plants, which is helpful for understanding the evolution of different

  14. Microdissection and chromosome painting of the alien chromosome in an addition line of wheat--Thinopyrum intermedium.

    Directory of Open Access Journals (Sweden)

    Chuanliang Deng

    Full Text Available In this study, chromosome painting was developed and used to identify alien chromosomes in TAi-27, a wheat--Thinopyrum intermedium addition line, and the chromosomes of the three different genomes of Th. Intermedium. The smallest alien chromosome of TAi-27 was microdissected and its DNA amplified by DOP-PCR was used as a probe to hybridize with metaphase chromosomes of TAi-27 and Th. intermedium. Results showed that hybridization signals were observed in all regions of a pair of the smallest alien chromosomes and the pericentromeric area of another pair of alien chromosomes in TAi-27, indicating that the probe from microdissected chromosome is species specific. In Th. intermedium, 14 chromosomes had wide and strong hybridization signals distributed mainly on the pericentromere area and 9 chromosomes with narrow and weak signals on the pericentromere area. The remaining chromosomes displayed a very weak or no signal. Sequential FISH/GISH on Th. intermedium chromosomes using the DNAs of microdissected chromosome, Pseudoroegneria spicata (St genome and pDbH12 (a J(s genome specific probe as the probes indicated that the microdissected chromosome belonged to the St genome, three genomes (J(s , J and St in Th. intermedium could be distinguished, in which there is no hybridization signal on J genome that is similar to the genome of Th. bessarabicum. Our results showed that the smallest alien chromosomes may represent a truncated chromosome and the repetitive sequence distribution might be similar in different chromosomes within the St genome. However, the repetitive sequence distributions are different within the J(s genome, within a single chromosome, and among different genomes in Th. intermedium. Our results suggested that chromosome painting could be feasible in some plants and useful in detecting chromosome variation and repetitive sequence distribution in different genomes of polyploidy plants, which is helpful for understanding the evolution of

  15. Fluorescence in situ hybridization: an improved method of quantitating chromosome damage and repair

    International Nuclear Information System (INIS)

    Brown, J.M.; Evans, J.W.

    1993-01-01

    The authors combined fluorescence in situ hybridization (FISH) with specific full-length chromosome probes using the premature chromosome condensation (PCC) technique chromosome condensation (PCC) technique to simplify scoring chromosome damage and its repair. They have shown the technique works well and enables breaks and exchanges to be readily detected and scored in individual chromosomes. A chromosome 4 full-length specific library has been used in initial studies. (UK)

  16. A Marfan syndrome-like phenotype caused by a neocentromeric supernumerary ring chromosome 15.

    Science.gov (United States)

    Quinonez, Shane C; Gelehrter, Thomas D; Uhlmann, Wendy R

    2017-01-01

    Small supernumerary marker chromosomes (sSMC) are abnormal chromosomes that cannot be characterized by standard banding cytogenetic techniques. A minority of sSMC contain a neocentromere, which is an ectopic centromere lacking the characteristic alpha-satellite DNA. The phenotypic manifestations of sSMC and neocentromeric sSMC are variable and range from severe intellectual disability and multiple congenital anomalies to a normal phenotype. Here we report a patient with a diagnosis of Marfan syndrome and infertility found to have an abnormal karyotype consisting of a chromosome 15 deletion and a ring-type sSMC likely stabilized by a neocentromere derived via a mechanism initially described by Barbara McClintock in 1938. Analysis of the sSMC identified that it contained the deleted chromosome 15 material and also one copy of FBN1, the gene responsible for Marfan syndrome. We propose that the patient's diagnosis arose from disruption of the FBN1 allele on the sSMC. To date, a total of 29 patients have been reported with an sSMC derived from a chromosomal deletion. We review these cases with a specific focus on the resultant phenotypes and note significant difference between this class of sSMC and other types of sSMC. Through this review we also identified a patient with a clinical diagnosis of neurofibromatosis type 1 who lacked a family history of the condition but was found to have a chromosome 17-derived sSMC that likely contained NF1 and caused the patient's disorder. We also review the genetic counseling implications and recommendations for a patient or family harboring an sSMC. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  17. Molecular diagnostic testing for Klinefelter syndrome and other male sex chromosome aneuploidies

    Directory of Open Access Journals (Sweden)

    Hager Karl

    2012-04-01

    Full Text Available Abstract Background Male sex chromosome aneuploidies are underdiagnosed despite concomitant physical and behavioral manifestations. Objective To develop a non-invasive, rapid and high-throughput molecular diagnostic assay for detection of male sex chromosome aneuploidies, including 47,XXY (Klinefelter, 47,XYY, 48,XXYY and 48,XXXY syndromes. Methods The assay utilizes three XYM and four XA markers to interrogate Y:X and X:autosome ratios, respectively. The seven markers were PCR amplified using genomic DNA isolated from a cohort of 323 males with aneuploid (n = 117 and 46,XY (n = 206 karyotypes. The resulting PCR products were subjected to Pyrosequencing, a quantitative DNA sequencing method. Results Receiver operator characteristic (ROC curves were used to establish thresholds for the discrimination of aneuploid from normal samples. The XYM markers permitted the identification of 47,XXY, 48,XXXY and 47,XYY syndromes with 100% sensitivity and specificity in both purified DNA and buccal swab samples. The 48,XXYY karyotype was delineated by XA marker data from 46,XY; an X allele threshold of 43% also permitted detection of 48,XXYY with 100% sensitivity and specificity. Analysis of X chromosome-specific biallelic SNPs demonstrated that 43 of 45 individuals (96% with 48,XXYY karyotype had two distinct X chromosomes, while 2 (4% had a duplicate X, providing evidence that 48,XXYY may result from nondisjunction during early mitotic divisions of a 46,XY embryo. Conclusions Quantitative Pyrosequencing, with high-throughput potential, can detect male sex chromosome aneuploidies with 100% sensitivity.

  18. Sex-specific effects on spatial learning and memory, and sex-independent effects on blood pressure of a <3.3 Mbp rat chromosome 2 QTL region in Dahl salt-sensitive rats.

    Directory of Open Access Journals (Sweden)

    Victoria L Herrera

    Full Text Available Epidemiological studies have consistently found that hypertension is associated with poor cognitive performance. We hypothesize that a putative causal mechanism underlying this association is due to genetic loci affecting both blood pressure and cognition. Consistent with this notion, we reported several blood pressure (BP quantitative trait loci (QTLs that co-localized with navigational performance (Nav-QTLs influencing spatial learning and memory in Dahl rats. The present study investigates a chromosome 2 region harboring BP-f4 and Nav-8 QTLs. We developed two congenic strains, S.R2A and S.R2B introgressing Dahl R-chromosome 2 segments into Dahl S chromosome 2 region spanning BP-f4 and Nav-8 QTLs. Radiotelemetric blood pressure analysis identified only S.R2A congenic rats with lower systolic blood pressure (females: -26.0 mmHg, P = 0.003; males: -30.9 mmHg, P<1×10(-5, diastolic blood pressure (females: -21.2 mmHg, P = 0.01; males: -25.7 mmHg, P<1×10(-5, and mean arterial pressure (females: -23.9 mmHg, P = 0.004; males: -28.0 mmHg, P<1×10(-5 compared with corresponding Dahl S controls, confirming the presence of BP-f4 QTL on rat chromosome 2. The S.R2B congenic segment did not affect blood pressure. Testing of S.R2A, S.R2B, and Dahl S male rats in the Morris water maze (MWM task revealed significantly decreased spatial navigation performance in S.R2A male congenic rats when compared with Dahl S male controls (P<0.05. The S.R2B congenic segment did not affect performance of the MWM task in males. The S.R2A female rats did not differ in spatial navigation when compared with Dahl S female controls, indicating that the Nav-8 effect on spatial navigation is male-specific. Our results suggest the existence of a single QTL on chromosome 2 176.6-179.9 Mbp region which affects blood pressure in both males and females and cognition solely in males.

  19. Sex-specific effects on spatial learning and memory, and sex-independent effects on blood pressure of a <3.3 Mbp rat chromosome 2 QTL region in Dahl salt-sensitive rats.

    Science.gov (United States)

    Herrera, Victoria L; Pasion, Khristine A; Tan, Glaiza A; Moran, Ann Marie; Ruiz-Opazo, Nelson

    2013-01-01

    Epidemiological studies have consistently found that hypertension is associated with poor cognitive performance. We hypothesize that a putative causal mechanism underlying this association is due to genetic loci affecting both blood pressure and cognition. Consistent with this notion, we reported several blood pressure (BP) quantitative trait loci (QTLs) that co-localized with navigational performance (Nav)-QTLs influencing spatial learning and memory in Dahl rats. The present study investigates a chromosome 2 region harboring BP-f4 and Nav-8 QTLs. We developed two congenic strains, S.R2A and S.R2B introgressing Dahl R-chromosome 2 segments into Dahl S chromosome 2 region spanning BP-f4 and Nav-8 QTLs. Radiotelemetric blood pressure analysis identified only S.R2A congenic rats with lower systolic blood pressure (females: -26.0 mmHg, P = 0.003; males: -30.9 mmHg, P<1×10(-5)), diastolic blood pressure (females: -21.2 mmHg, P = 0.01; males: -25.7 mmHg, P<1×10(-5)), and mean arterial pressure (females: -23.9 mmHg, P = 0.004; males: -28.0 mmHg, P<1×10(-5)) compared with corresponding Dahl S controls, confirming the presence of BP-f4 QTL on rat chromosome 2. The S.R2B congenic segment did not affect blood pressure. Testing of S.R2A, S.R2B, and Dahl S male rats in the Morris water maze (MWM) task revealed significantly decreased spatial navigation performance in S.R2A male congenic rats when compared with Dahl S male controls (P<0.05). The S.R2B congenic segment did not affect performance of the MWM task in males. The S.R2A female rats did not differ in spatial navigation when compared with Dahl S female controls, indicating that the Nav-8 effect on spatial navigation is male-specific. Our results suggest the existence of a single QTL on chromosome 2 176.6-179.9 Mbp region which affects blood pressure in both males and females and cognition solely in males.

  20. Characterization of X chromosome inactivation using integrated analysis of whole-exome and mRNA sequencing.

    Directory of Open Access Journals (Sweden)

    Szabolcs Szelinger

    Full Text Available In females, X chromosome inactivation (XCI is an epigenetic, gene dosage compensatory mechanism by inactivation of one copy of X in cells. Random XCI of one of the parental chromosomes results in an approximately equal proportion of cells expressing alleles from either the maternally or paternally inherited active X, and is defined by the XCI ratio. Skewed XCI ratio is suggestive of non-random inactivation, which can play an important role in X-linked genetic conditions. Current methods rely on indirect, semi-quantitative DNA methylation-based assay to estimate XCI ratio. Here we report a direct approach to estimate XCI ratio by integrated, family-trio based whole-exome and mRNA sequencing using phase-by-transmission of alleles coupled with allele-specific expression analysis. We applied this method to in silico data and to a clinical patient with mild cognitive impairment but no clear diagnosis or understanding molecular mechanism underlying the phenotype. Simulation showed that phased and unphased heterozygous allele expression can be used to estimate XCI ratio. Segregation analysis of the patient's exome uncovered a de novo, interstitial, 1.7 Mb deletion on Xp22.31 that originated on the paternally inherited X and previously been associated with heterogeneous, neurological phenotype. Phased, allelic expression data suggested an 83∶20 moderately skewed XCI that favored the expression of the maternally inherited, cytogenetically normal X and suggested that the deleterious affect of the de novo event on the paternal copy may be offset by skewed XCI that favors expression of the wild-type X. This study shows the utility of integrated sequencing approach in XCI ratio estimation.

  1. X-Chromosomal short tandem repeat loci in the Turkish population ...

    African Journals Online (AJOL)

    In this study, we aimed to demonstrate the importance and utility of polymorphic short tandem repeat (STR) found on the human X chromosome and to provide the first allelic frequency data of X-STR (X chromosomal) loci in the Turkish population. Blood samples were taken from unrelated individuals (135 males and 129 ...

  2. Chromosome analysis of arsenic affected cattle

    Directory of Open Access Journals (Sweden)

    S. Shekhar

    2014-10-01

    Full Text Available Aim: The aim was to study the chromosome analysis of arsenic affected cattle. Materials and Methods: 27 female cattle (21 arsenic affected and 6 normal were selected for cytogenetical study. The blood samples were collected, incubated, and cultured using appropriate media and specific methods. The samples were analyzed for chromosome number and morphology, relative length of the chromosome, arm ratio, and centromere index of X chromosome and chromosomal abnormalities in arsenic affected cattle to that of normal ones. Results: The diploid number of metaphase chromosomes in arsenic affected cattle as well as in normal cattle were all 2n=60, 58 being autosomes and 2 being sex chromosomes. From the centromeric position, karyotyping studies revealed that all the 29 pair of autosomes was found to be acrocentric or telocentric, and the sex chromosomes (XX were submetacentric in both normal and arsenic affected cattle. The relative length of all the autosome pairs and sex chrosomosome pair was found to be higher in normal than that of arsenic affected cattle. The mean arm ratio of X-chromosome was higher in normal than that of arsenic affected cattle, but it is reverse in case of centromere index value of X-chromosome. There was no significant difference of arm ratio and centromere index of X-chromosomes between arsenic affected and normal cattle. No chromosomal abnormalities were found in arsenic affected cattle. Conclusion: The chromosome analysis of arsenic affected cattle in West Bengal reported for the first time in this present study which may serve as a guideline for future studies in other species. These reference values will also help in comparison of cytological studies of arsenic affected cattle to that of various toxicants.

  3. Identification of the sex-determining locus in grass puffer (Takifugu niphobles) provides evidence for sex-chromosome turnover in a subset of Takifugu species

    Science.gov (United States)

    Atsumi, Kazufumi; Kamiya, Takashi; Nozawa, Aoi; Aoki, Yuma; Tasumi, Satoshi; Koyama, Takashi; Nakamura, Osamu; Suzuki, Yuzuru

    2018-01-01

    There is increasing evidence for frequent turnover in sex chromosomes in vertebrates. Yet experimental systems suitable for tracing the detailed process of turnover are rare. In theory, homologous turnover is possible if the new sex-determining locus is established on the existing sex-chromosome. However, there is no empirical evidence for such an event. The genus Takifugu includes fugu (Takifugu rubripes) and its two closely-related species whose sex is most likely determined by a SNP at the Amhr2 locus. In these species, males are heterozygous, with G and C alleles at the SNP site, while females are homozygous for the C allele. To determine if a shift in the sex-determining locus occurred in another member of this genus, we used genetic mapping to characterize the sex-chromosome systems of Takifugu niphobles. We found that the G allele of Amhr2 is absent in T. niphobles. Nevertheless, our initial mapping suggests a linkage between the phenotypic sex and the chromosome 19, which harbors the Amhr2 locus. Subsequent high-resolution analysis using a sex-reversed fish demonstrated that the sex-determining locus maps to the proximal end of chromosome 19, far from the Amhr2 locus. Thus, it is likely that homologous turnover involving these species has occurred. The data also showed that there is a male-specific reduction of recombination around the sex-determining locus. Nevertheless, no evidence for sex-chromosome differentiation was detected: the reduced recombination depended on phenotypic sex rather than genotypic sex; no X- or Y-specific maker was obtained; the YY individual was viable. Furthermore, fine-scale mapping narrowed down the new sex-determining locus to the interval corresponding to approximately 300-kb of sequence in the fugu genome. Thus, T. niphobles is determined to have a young and small sex-determining region that is suitable for studying an early phase of sex-chromosome evolution and the mechanisms underlying turnover of sex chromosome. PMID

  4. Prevalence of Huntington's disease gene CAG trinucleotide repeat alleles in patients with bipolar disorder.

    Science.gov (United States)

    Ramos, Eliana Marisa; Gillis, Tammy; Mysore, Jayalakshmi S; Lee, Jong-Min; Alonso, Isabel; Gusella, James F; Smoller, Jordan W; Sklar, Pamela; MacDonald, Marcy E; Perlis, Roy H

    2015-06-01

    Huntington's disease is a neurodegenerative disorder characterized by motor, cognitive, and psychiatric symptoms that are caused by huntingtin gene (HTT) CAG trinucleotide repeat alleles of 36 or more units. A greater than expected prevalence of incompletely penetrant HTT CAG repeat alleles observed among individuals diagnosed with major depressive disorder raises the possibility that another mood disorder, bipolar disorder, could likewise be associated with Huntington's disease. We assessed the distribution of HTT CAG repeat alleles in a cohort of individuals with bipolar disorder. HTT CAG allele sizes from 2,229 Caucasian individuals diagnosed with DSM-IV bipolar disorder were compared to allele sizes in 1,828 control individuals from multiple cohorts. We found that HTT CAG repeat alleles > 35 units were observed in only one of 4,458 chromosomes from individuals with bipolar disorder, compared to three of 3,656 chromosomes from control subjects. These findings do not support an association between bipolar disorder and Huntington's disease. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Insertional engineering of chromosomes with Sleeping Beauty transposition: an overview.

    Science.gov (United States)

    Grabundzija, Ivana; Izsvák, Zsuzsanna; Ivics, Zoltán

    2011-01-01

    Novel genetic tools and mutagenesis strategies based on the Sleeping Beauty (SB) transposable element are currently under development with a vision to link primary DNA sequence information to gene functions in vertebrate models. By virtue of its inherent capacity to insert into DNA, the SB transposon can be developed into powerful tools for chromosomal manipulations. Mutagenesis screens based on SB have numerous advantages including high throughput and easy identification of mutated alleles. Forward genetic approaches based on insertional mutagenesis by engineered SB transposons have the advantage of providing insight into genetic networks and pathways based on phenotype. Indeed, the SB transposon has become a highly instrumental tool to induce tumors in experimental animals in a tissue-specific -manner with the aim of uncovering the genetic basis of diverse cancers. Here, we describe a battery of mutagenic cassettes that can be applied in conjunction with SB transposon vectors to mutagenize genes, and highlight versatile experimental strategies for the generation of engineered chromosomes for loss-of-function as well as gain-of-function mutagenesis for functional gene annotation in vertebrate models.

  6. Genome association study of human chromosome 13 and ...

    Indian Academy of Sciences (India)

    Ministry of Health, Department of Cardiology, Qilu Hospital of Shandong University,. Jinan, Shandong ... chromosome 13 and susceptibility to coronary artery disease in a Chinese population. J. Genet. .... of the 164 bp allele in cases was significantly lower than .... 5-lipoxygenase activating protein (FLAP), is associated with.

  7. 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 ...

  8. Genetic Analysis of Eight X-Chromosomal Short Tandem Repeat ...

    African Journals Online (AJOL)

    X-Chromosome short tandem repeat (STR) typing can complement existing DNA profiling protocols and can also offer useful information in cases of complex kinship analysis. This is the first population study of 8 X-linked STRs in Iraq. The purpose of this work was to provide a basic data of allele and haplotype frequency for ...

  9. HLA Dr beta 1 alleles in Pakistani patients with rheumatoid arthritis

    International Nuclear Information System (INIS)

    Naqi, N.; Ahmed, T.A.; Bashir, M.M.

    2011-01-01

    Objective: To determine frequencies of HLA DR beta 1 alleles in rheumatoid arthritis in Pakistani patients. Study Design: Cross sectional / analytical study. Place and Duration of Study: Department of Immunology, Armed Forces Institute of Pathology, Rawalpindi in collaboration with Rheumatology departments of Military Hospital, Rawalpindi and Fauji Foundation Hospital, Rawalpindi, from January 2009 to January 2010. Methodology: HLA DR beta 1 genotyping of one hundred Pakistani patients, diagnosed as having RA as per American College of Rheumatology revised criteria 1987, was done. HLA DR beta 1 genotyping was carried out at allele group level (DR beta 1*01-DR beta 1*16) by sequence specific primers in RA patients. Comparison of HLA DR beta 1 allele frequencies between patients and control groups was made using Pearson's chi-square test to find possible association of HLA DR?1 alleles with RA in Pakistani rheumatoid patients. Results: HLA DR beta 1*04 was expressed with significantly increased frequency in patients with rheumatoid arthritis (p <0.05). HLA DR?1*11 was expressed statistically significantly more in control group as compared to rheumatoid patients indicating a possible protective effect. There was no statistically significant difference observed in frequencies of HLA DR beta 1 allele *01, DR beta 1 allele *03, DR beta 1 allele *07, DR beta 1 allele *08, DR beta 1 allele *09, DR beta 1 allele *10, DR beta 1 allele *12, DR beta 1 allele *13, DR beta 1 allele *14, DR?1 allele *15 and DR beta 1 allele *16 between patients and control groups. Conclusion: The identification of susceptible HLA DR beta 1 alleles in Pakistani RA patients may help physicians to make early decisions regarding initiation of early intensive therapy with disease modifying anti rheumatic medicines and biological agents decreasing disability in RA patients. (author)

  10. From equator to pole: splitting chromosomes in mitosis and meiosis

    Science.gov (United States)

    Duro, Eris

    2015-01-01

    During eukaryotic cell division, chromosomes must be precisely partitioned to daughter cells. This relies on a mechanism to move chromosomes in defined directions within the parental cell. While sister chromatids are segregated from one another in mitosis and meiosis II, specific adaptations enable the segregation of homologous chromosomes during meiosis I to reduce ploidy for gamete production. Many of the factors that drive these directed chromosome movements are known, and their molecular mechanism has started to be uncovered. Here we review the mechanisms of eukaryotic chromosome segregation, with a particular emphasis on the modifications that ensure the segregation of homologous chromosomes during meiosis I. PMID:25593304

  11. 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.

  12. 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

  13. Fetal chromosome analysis: screening for chromosome disease?

    DEFF Research Database (Denmark)

    Philip, J; Tabor, Ann; Bang, J

    1983-01-01

    The aim of the study was to investigate the rationale of the current indications for fetal chromosome analysis. 5372 women had 5423 amniocentesis performed, this group constituting a consecutive sample at the chromosome laboratory, Rigshospitalet, Copenhagen from March 1973 to September 1980 (Group...... A + B). Pregnant women 35 years of age, women who previously had a chromosomally abnormal child, families with translocation carriers or other heritable chromosomal disease, families where the father was 50 years or more and women in families with a history of Down's syndrome (group A), were compared...... to women having amniocentesis, although considered not to have any increased risk of fetal chromosome abnormality (1390 pregnancies, group B). They were also compared with 750 consecutive pregnancies in women 25-34 years of age, in whom all heritable diseases were excluded (group C). The risk of unbalanced...

  14. Semi-automatic laser beam microdissection of the Y chromosome and analysis of Y chromosome DNA in a dioecious plant, Silene latifolia

    International Nuclear Information System (INIS)

    Matsunaga, S.; Kawano, S.; Michimoto, T.; Higashiyama, T.; Nakao, S.; Sakai, A.; Kuroiwa, T.

    1999-01-01

    Silene latifolia has heteromorphic sex chromosomes, the X and Y chromosomes. The Y chromosome, which is thought to carry the male determining gene, was isolated by UV laser microdissection and amplified by degenerate oligonucleotide-primed PCR. In situ chromosome suppression of the amplified Y chromosome DNA in the presence of female genomic DNA as a competitor showed that the microdissected Y chromosome DNA did not specifically hybridize to the Y chromosome, but-hybridized to all chromosomes. This result suggests that the Y chromosome does not contain Y chromosome-enriched repetitive sequences. A repetitive sequence in the microdissected Y chromosome, RMY1, was isolated while screening repetitive sequences in the amplified Y chromosome. Part of the nucleotide sequence shared a similarity to that of X-43.1, which was isolated from microdissected X chromosomes. Since fluorescence in situ hybridization analysis with RMY1 demonstrated that RMY1 was localized at the ends of the chromosome, RMY1 may be a subtelomeric repetitive sequence. Regarding the sex chromosomes, RMY1 was detected at both ends of the X chromosome and at one end near the pseudoautosomal region of the Y chromosome. The different localization of RMY1 on the sex chromosomes provides a clue to the problem of how the sex chromosomes arose from autosomes

  15. REC46 gene of Saccharomyces cerevisiae controls mitotic chromosomal stability, recombination and sporulation: cell-type and life cycle stage specific expression of the rec46-1 mutation

    International Nuclear Information System (INIS)

    Maleas, D.T.; Bjornstad, K.A.; Holbrook, L.L.; Esposito, M.S.

    1986-01-01

    Studies of chromosomal recombination during mitosis and meiosis of Saccharomyces cerevisiae have demonstrated that recombination at these two distinct stages of the yeast life cycle proceeds by mechanisms that appear similar but involve discrete mitosis-specific and meiosis-specific properties. UV radiation induced REC mutants are being employed as a genetic tool to identify the partial reactions comprising recombination and the involvement of individual REC gene products in mitotic and meiotic recombination. The sequence of molecular events that results in genetic recombination in eukaryotes is presently ill-defined. Genetic characterization of REC gene mutants and biochemical analyses of them for discrete defects in DNA metabolic proteins and enzymes (in collaboration with the laboratory of Junko Hosoda) are beginning to remedy this gap in the authors knowledge. This report summarizes the genetic properties of the rec46-1 mutation

  16. Characterization of A-11, a newly discovered X-chromosomal gene that is under both single-active-X control and tissue-specific control

    International Nuclear Information System (INIS)

    Nadon, N.L.

    1987-01-01

    The A-11 transcript is present in fibroblasts, but is not normally expressed in B- or T-lymphoblastoid cells. The regulation of the A-11 loci on both the active and inactive X chromosomes is very easily perturbed. The A-11 locus on the fibroblast-derived inactive X in a hybrid cell is reactivated at a very high rate by 5-azacytidine, an inhibitor of DNA methylation, while the A-11 locus on the active X in B-lymphoblastoid cells is derepressed at a very high rate after gamma irradiation. The A-11 gene codes for a mature transcript of about 1.9 kb. The A-11 cDNA clone is incomplete, and contains 753 bases from the 3' end of the gene. A genomic clone that contains about 17 kb of human DNA and hybridizes to the A-11 cDNA was isolated. This clone contains at least the last exon of the A-11 gene, as determined by Northern blotting, nuclease protection experiments, and DNA sequencing. When the genomic clone is transferred into mouse cells. A-11 transcripts of both normal and abnormal sizes are produced, indicating that it is possible that the genomic clone contains the entire locus. However, at this time, the 5' end of the gene has not been located

  17. SCREENING LOW FREQUENCY SNPS FROM GENOME WIDE ASSOCIATION STUDY REVEALS A NEW RISK ALLELE FOR PROGRESSION TO AIDS

    Science.gov (United States)

    Le Clerc, Sigrid; Coulonges, Cédric; Delaneau, Olivier; Van Manen, Danielle; Herbeck, Joshua T.; Limou, Sophie; An, Ping; Martinson, Jeremy J.; Spadoni, Jean-Louis; Therwath, Amu; Veldink, Jan H.; van den Berg, Leonard H.; Taing, Lieng; Labib, Taoufik; Mellak, Safa; Montes, Matthieu; Delfraissy, Jean-François; Schächter, François; Winkler, Cheryl; Froguel, Philippe; Mullins, James I.; Schuitemaker, Hanneke; Zagury, Jean-François

    2011-01-01

    Background Seven genome-wide association studies (GWAS) have been published in AIDS and only associations in the HLA region on chromosome 6 and CXCR6 have passed genome-wide significance. Methods We reanalyzed the data from three previously published GWAS, targeting specifically low frequency SNPs (minor allele frequency (MAF)<5%). Two groups composed of 365 slow progressors (SP) and 147 rapid progressors (RP) from Europe and the US were compared with a control group of 1394 seronegative individuals using Eigenstrat corrections. Results Of the 8584 SNPs with MAF<5% in cases and controls (Bonferroni threshold=5.8×10−6), four SNPs showed statistical evidence of association with the SP phenotype. The best result was for HCP5 rs2395029 (p=8.54×10−15, OR=3.41) in the HLA locus, in partial linkage disequilibrium with two additional chromosome 6 associations in C6orf48 (p=3.03×10−10, OR=2.9) and NOTCH4 (9.08×10−07, OR=2.32). The fourth association corresponded to rs2072255 located in RICH2 (p=3.30×10−06, OR=0.43) in chromosome 17. Using HCP5 rs2395029 as a covariate, the C6orf48 and NOTCH4 signals disappeared, but the RICH2 signal still remained significant. Conclusion Besides the already known chromosome 6 associations, the analysis of low frequency SNPs brought up a new association in the RICH2 gene. Interestingly, RICH2 interacts with BST-2 known to be a major restriction factor for HIV-1 infection. Our study has thus identified a new candidate gene for AIDS molecular etiology and confirms the interest of singling out low frequency SNPs in order to exploit GWAS data. PMID:21107268

  18. Chromosome painting in plants.

    NARCIS (Netherlands)

    Schubert, I.; Fransz, P.F.; Fuchs, J.; Jong, de J.H.

    2001-01-01

    The current 'state-of-art' as to chromosome painting in plants is reviewed. We define different situations described as painting so far: i) Genomic in situ hybridisation (GISH) with total genomic DNA to distinguish alien chromosomes on the basis of divergent dispersed repeats, ii) 'Chromosomal in

  19. Isolation of anonymous, polymorphic DNA fragments from human chromosome 22q12-qter

    NARCIS (Netherlands)

    J.P. Dumanski (Jan); A.H.M. Geurts van Kessel (Ad); M. Ruttledge (Martin); A. Wladis (Andreas); N. Sugawa (Noriaki); V.P. Collins (Peter); M. Nordenskjöld

    1990-01-01

    textabstractA series of 195 random chromosome 22-specific probes, equivalent to approximately 1% of the size of this chromosome, have been isolated from a chromosome 22-specific bacteriophage lambda genomic library. These probes were mapped to four different regions of chromosome 22 on a panel of

  20. B chromosomes are associated with redistribution of genetic recombination towards lower recombination chromosomal regions in perennial ryegrass.

    Science.gov (United States)

    Harper, John; Phillips, Dylan; Thomas, Ann; Gasior, Dagmara; Evans, Caron; Powell, Wayne; King, Julie; King, Ian; Jenkins, Glyn; Armstead, Ian

    2018-04-09

    Supernumerary 'B' chromosomes are non-essential components of the genome present in a range of plant and animal species-including many grasses. Within diploid and polyploid ryegrass and fescue species, including the forage grass perennial ryegrass (Lolium perenne L.), the presence of B chromosomes has been reported as influencing both chromosome pairing and chiasma frequencies. In this study, the effects of the presence/absence of B chromosomes on genetic recombination has been investigated through generating DArT (Diversity Arrays Technology) marker genetic maps for six perennial ryegrass diploid populations, the pollen parents of which contained either two B or zero B chromosomes. Through genetic and cytological analyses of these progeny and their parents, we have identified that, while overall cytological estimates of chiasma frequencies were significantly lower in pollen mother cells with two B chromosomes as compared with zero B chromosomes, the recombination frequencies within some marker intervals were actually increased, particularly for marker intervals in lower recombination regions of chromosomes, namely pericentromeric regions. Thus, in perennial ryegrass, the presence of two B chromosomes redistributed patterns of meiotic recombination in pollen mother cells in ways which could increase the range of allelic variation available to plant breeders.

  1. Allelic imbalance and fine mapping of the 17p13.3 subregion in sporadic breast carcinomas

    DEFF Research Database (Denmark)

    Hoff, C; Mollenhauer, J; Waldau, B

    2001-01-01

    Chromosome arm 17p is frequently altered in a variety of human cancers, especially in breast cancer, and allelic imbalances (AIs) in the region 17p13.1 do not always coincide with mutations in the TP53 gene. A second interval that frequently shows AIs at 17p is the chromosomal band 17p13.3. This ......Chromosome arm 17p is frequently altered in a variety of human cancers, especially in breast cancer, and allelic imbalances (AIs) in the region 17p13.1 do not always coincide with mutations in the TP53 gene. A second interval that frequently shows AIs at 17p is the chromosomal band 17p13...

  2. Improved multiplex ligation-dependent probe amplification analysis identifies a deleterious PMS2 allele generated by recombination with crossover between PMS2 and PMS2CL.

    Science.gov (United States)

    Wernstedt, Annekatrin; Valtorta, Emanuele; Armelao, Franco; Togni, Roberto; Girlando, Salvatore; Baudis, Michael; Heinimann, Karl; Messiaen, Ludwine; Staehli, Noemie; Zschocke, Johannes; Marra, Giancarlo; Wimmer, Katharina

    2012-09-01

    Heterozygous PMS2 germline mutations are associated with Lynch syndrome. Up to one third of these mutations are genomic deletions. Their detection is complicated by a pseudogene (PMS2CL), which--owing to extensive interparalog sequence exchange--closely resembles PMS2 downstream of exon 12. A recently redesigned multiplex ligation-dependent probe amplification (MLPA) assay identifies PMS2 copy number alterations with improved reliability when used with reference DNAs containing equal numbers of PMS2- and PMS2CL-specific sequences. We selected eight such reference samples--all publicly available--and used them with this assay to study 13 patients with PMS2-defective colorectal tumors. Three presented deleterious alterations: an Alu-mediated exon deletion; a 125-kb deletion encompassing PMS2 and four additional genes (two with tumor-suppressing functions); and a novel deleterious hybrid PMS2 allele produced by recombination with crossover between PMS2 and PMS2CL, with the breakpoint in intron 10 (the most 5' breakpoint of its kind reported thus far). We discuss mechanisms that might generate this allele in different chromosomal configurations (and their diagnostic implications) and describe an allele-specific PCR assay that facilitates its detection. Our data indicate that the redesigned PMS2 MLPA assay is a valid first-line option. In our series, it identified roughly a quarter of all PMS2 mutations. Copyright © 2012 Wiley Periodicals, Inc.

  3. Retrospective dosimetry using chromosome painting

    International Nuclear Information System (INIS)

    Nasazzi, N.B.; Giorgio, M.D.; Taja, M.R.

    2000-01-01

    Chromosome aberration frequency measured in peripheral lymphocytes of persons exposed to ionizing radiation has been used since 1960s for dose assessment. Suspected overexposure is usually evaluated by the frequency of dicentrics and centric rings using an appropriate in vitro calibration curve. However, these chromosome aberrations are unstable with time after exposure and dose reconstruction may encounter uncertainties when the time between the exposure and the analysis is considerable or even unknown. It appears that translocations persist with time after exposure and may be used as an indication of acute past overexposures. Moreover, they appear to accumulate the cytogenetical information, which correlates with the dose received under fractionated, chronic or even occupational exposure conditions. Translocations may be detected using G-banding, which allows to score the total amount of radiation induced translocations but it is a time consuming method, or by Chromosome Painting, a method base on the Fluorescence in situ Hybridization (FISH) technique, painting only some chromosome pairs with specific whole chromosome probes and then extrapolating the observed translocation frequencies to the full genome. The latter method allows a faster aberration scoring than G-banding and appears to be the most promissory tool for biodosimetry, particularly when it is necessary to assess low doses and consequently to score a large number of metaphases, e.g. radiation workers exposed within dose limits. As with the unstable chromosome aberration, it is necessary an in vitro calibration curve based on the frequency of stable chromosome aberrations to assess doses. Our laboratory performed calibration curves for Co 60 γ-rays based on the frequencies of unstable (dicentrics and centric rings detected by conventional Giemsa staining) and stable chromosome aberrations (translocations and inversions, detected by G-banding). In order to minimize the interlaboratory variability, we

  4. Painting of fourth and chromosome-wide regulation of the 4th chromosome in Drosophila melanogaster.

    Science.gov (United States)

    Johansson, Anna-Mia; Stenberg, Per; Bernhardsson, Carolina; Larsson, Jan

    2007-05-02

    Drosophila melanogaster exhibits two expression-regulating systems that target whole, specific chromosomes: the dosage compensation system whereby the male-specific lethal complex doubles transcription of genes on the male X-chromosome and the chromosome 4-specific protein Painting of fourth, POF. POF is the first example of an autosome-specific protein and its presence raises the question of the universality of chromosome-specific regulation. Here we show that POF and heterochromatin protein 1 (HP1) are involved in the global regulation of the 4th chromosome. Contrary to previous conclusions, Pof is not essential for survival of diplo-4th karyotype flies. However, Pof is essential for survival of haplo-4th individuals and expression of chromosome 4 genes in diplo-4th individuals is decreased in the absence of Pof. Mapping of POF using chromatin immunoprecipitation suggested that it binds within genes. Furthermore, we show that POF binding is dependent on heterochromatin and that POF and HP1 bind interdependently to the 4th chromosome. We propose a balancing mechanism involving POF and HP1 that provides a feedback system for fine-tuning expression status of genes on the 4th chromosome.

  5. Sensory Gating and Alpha-7 Nicotinic Receptor Gene Allelic Variants in Schizoaffective Disorder, Bipolar Type

    Science.gov (United States)

    Martin, Laura F.; Leonard, Sherry; Hall, Mei-Hua; Tregellas, Jason R.; Freedman, Robert; Olincy, Ann

    2011-01-01

    Objectives Single nucleotide allelic variants in the promoter region of the chromosome 15 alpha-7 acetylcholine nicotinic receptor gene (CHRNA7) are associated with both schizophrenia and the P50 auditory evoked potential sensory gating deficit. The purpose of this study was to determine if CHRNA7 promoter allelic variants are also associated with abnormal P50 ratios in persons with schizoaffective disorder, bipolar type. Methods P50 auditory evoked potentials were recorded in a paired stimulus paradigm in 17 subjects with schizoaffective disorder, bipolar type. The P50 test to conditioning ratio was used as the measure of sensory gating. Mutation screening of the CHRNA7 promoter region was performed on the subjects’ DNA samples. Comparisons to previously obtained data from persons with schizophrenia and controls were made. Results Subjects with schizophrenia, regardless of allele status, had an abnormal mean P50 ratio. Subjects with schizoaffective disorder, bipolar type and a variant allele had an abnormal mean P50 ratio, whereas those schizoaffective subjects with the common alleles had a normal mean P50 ratio. Normal control subjects had a normal mean ratio, but controls with variant alleles had higher P50 ratios. Conclusions In persons with bipolar type schizoaffective disorder, CHRNA7 promoter region allelic variants are linked to the capacity to inhibit the P50 auditory evoked potential and thus are associated with a type of illness genetically and biologically more similar to schizophrenia. PMID:17192894

  6. Allelic loss and prognosis in carcinoma of the uterine cervix

    NARCIS (Netherlands)

    Kersemaekers, A. M.; Kenter, G. G.; Hermans, J.; Fleuren, G. J.; van de Vijver, M. J.

    1998-01-01

    Cervical carcinomas develop as a result of multiple genetic alterations. As the genetic alterations are the cause of malignant transformation, it is likely that specific genetic alterations lead to specific clinical behaviour. The aim of this study was (i) to localise chromosome arms that harbour

  7. Establishment of a mouse model with misregulated chromosome condensation due to defective Mcph1 function.

    Directory of Open Access Journals (Sweden)

    Marc Trimborn

    Full Text Available Mutations in the human gene MCPH1 cause primary microcephaly associated with a unique cellular phenotype with premature chromosome condensation (PCC in early G2 phase and delayed decondensation post-mitosis (PCC syndrome. The gene encodes the BRCT-domain containing protein microcephalin/BRIT1. Apart from its role in the regulation of chromosome condensation, the protein is involved in the cellular response to DNA damage. We report here on the first mouse model of impaired Mcph1-function. The model was established based on an embryonic stem cell line from BayGenomics (RR0608 containing a gene trap in intron 12 of the Mcph1 gene deleting the C-terminal BRCT-domain of the protein. Although residual wild type allele can be detected by quantitative real-time PCR cell cultures generated from mouse tissues bearing the homozygous gene trap mutation display the cellular phenotype of misregulated chromosome condensation that is characteristic for the human disorder, confirming defective Mcph1 function due to the gene trap mutation. While surprisingly the DNA damage response (formation of repair foci, chromosomal breakage, and G2/M checkpoint function after irradiation appears to be largely normal in cell cultures derived from Mcph1(gt/gt mice, the overall survival rates of the Mcph1(gt/gt animals are significantly reduced compared to wild type and heterozygous mice. However, we could not detect clear signs of premature malignant disease development due to the perturbed Mcph1 function. Moreover, the animals show no obvious physical phenotype and no reduced fertility. Body and brain size are within the range of wild type controls. Gene expression on RNA and protein level did not reveal any specific pattern of differentially regulated genes. To the best of our knowledge this represents the first mammalian transgenic model displaying a defect in mitotic chromosome condensation and is also the first mouse model for impaired Mcph1-function.

  8. Establishment of a mouse model with misregulated chromosome condensation due to defective Mcph1 function.

    Science.gov (United States)

    Trimborn, Marc; Ghani, Mahdi; Walther, Diego J; Dopatka, Monika; Dutrannoy, Véronique; Busche, Andreas; Meyer, Franziska; Nowak, Stefanie; Nowak, Jean; Zabel, Claus; Klose, Joachim; Esquitino, Veronica; Garshasbi, Masoud; Kuss, Andreas W; Ropers, Hans-Hilger; Mueller, Susanne; Poehlmann, Charlotte; Gavvovidis, Ioannis; Schindler, Detlev; Sperling, Karl; Neitzel, Heidemarie

    2010-02-16

    Mutations in the human gene MCPH1 cause primary microcephaly associated with a unique cellular phenotype with premature chromosome condensation (PCC) in early G2 phase and delayed decondensation post-mitosis (PCC syndrome). The gene encodes the BRCT-domain containing protein microcephalin/BRIT1. Apart from its role in the regulation of chromosome condensation, the protein is involved in the cellular response to DNA damage. We report here on the first mouse model of impaired Mcph1-function. The model was established based on an embryonic stem cell line from BayGenomics (RR0608) containing a gene trap in intron 12 of the Mcph1 gene deleting the C-terminal BRCT-domain of the protein. Although residual wild type allele can be detected by quantitative real-time PCR cell cultures generated from mouse tissues bearing the homozygous gene trap mutation display the cellular phenotype of misregulated chromosome condensation that is characteristic for the human disorder, confirming defective Mcph1 function due to the gene trap mutation. While surprisingly the DNA damage response (formation of repair foci, chromosomal breakage, and G2/M checkpoint function after irradiation) appears to be largely normal in cell cultures derived from Mcph1(gt/gt) mice, the overall survival rates of the Mcph1(gt/gt) animals are significantly reduced compared to wild type and heterozygous mice. However, we could not detect clear signs of premature malignant disease development due to the perturbed Mcph1 function. Moreover, the animals show no obvious physical phenotype and no reduced fertility. Body and brain size are within the range of wild type controls. Gene expression on RNA and protein level did not reveal any specific pattern of differentially regulated genes. To the best of our knowledge this represents the first mammalian transgenic model displaying a defect in mitotic chromosome condensation and is also the first mouse model for impaired Mcph1-function.

  9. Expression and loss of alleles in cultured mouse embryonic fibroblasts and stem cells carrying allelic fluorescent protein genes

    Directory of Open Access Journals (Sweden)

    Stringer Saundra L

    2006-10-01

    Full Text Available Abstract Background Loss of heterozygosity (LOH contributes to many cancers, but the rate at which these events occur in normal cells of the body is not clear. LOH would be detectable in diverse cell types in the body if this event were to confer an obvious cellular phenotype. Mice that carry two different fluorescent protein genes as alleles of a locus would seem to be a useful tool for addressing this issue because LOH would change a cell's phenotype from dichromatic to monochromatic. In addition, LOH caused by mitotic crossing over might be discernable in tissues because this event produces a pair of neighboring monochromatic cells that are different colors. Results As a step in assessing the utility of this approach, we derived primary embryonic fibroblast populations and embryonic stem cell lines from mice that carried two different fluorescent protein genes as alleles at the chromosome 6 locus, ROSA26. Fluorescence activated cell sorting (FACS showed that the vast majority of cells in each line expressed the two marker proteins at similar levels, and that populations exhibited expression noise similar to that seen in bacteria and yeast. Cells with a monochromatic phenotype were present at frequencies on the order of 10-4 and appeared to be produced at a rate of approximately 10-5 variant cells per mitosis. 45 of 45 stably monochromatic ES cell clones exhibited loss of the expected allele at the ROSA26 locus. More than half of these clones retained heterozygosity at a locus between ROSA26 and the centromere. Other clones exhibited LOH near the centromere, but were disomic for chromosome 6. Conclusion Allelic fluorescent markers allowed LOH at the ROSA26 locus to be detected by FACS. LOH at this locus was usually not accompanied by LOH near the centromere, suggesting that mitotic recombination was the major cause of ROSA26 LOH. Dichromatic mouse embryonic cells provide a novel system for studying genetic/karyotypic stability and factors

  10. Assessment of the myostatin Q204X allele using an allelic discrimination assay

    OpenAIRE

    Sifuentes-Rincón,Ana M.; Puentes-Montiel,Herlinda E.; Moreno-Medina,Víctor R.; Rosa-Reyna,Xóchitl F. de la

    2006-01-01

    An allelic discrimination assay was designed and used to determine the genotypic and allelic frequencies of the myostatin (MSTN) gene Q204X allele from two Mexican Full-French herds. The assay is a simple high throughput genotyping method that could be applied to investigate the effect of the Q204X allele on the Charolais breed.

  11. Drop-out probabilities of IrisPlex SNP alleles

    DEFF Research Database (Denmark)

    Andersen, Jeppe Dyrberg; Tvedebrink, Torben; Mogensen, Helle Smidt

    2013-01-01

    In certain crime cases, information about a perpetrator's phenotype, including eye colour, may be a valuable tool if no DNA profile of any suspect or individual in the DNA database matches the DNA profile found at the crime scene. Often, the available DNA material is sparse and allelic drop-out...... of true alleles is possible. As part of the validation of the IrisPlex assay in our ISO17025 accredited, forensic genetic laboratory, we estimated the probability of drop-out of specific SNP alleles using 29 and 30 PCR cycles and 25, 50 and 100 Single Base Extension (SBE) cycles. We observed no drop-out...... when the amount of DNA was greater than 125 pg for 29 cycles of PCR and greater than 62 pg for 30 cycles of PCR. With the use of a logistic regression model, we estimated the allele specific probability of drop-out in heterozygote systems based on the signal strength of the observed allele...

  12. Purifying Selection Maintains Dosage-Sensitive Genes during Degeneration of the Threespine Stickleback Y Chromosome

    Science.gov (United States)

    White, Michael A.; Kitano, Jun; Peichel, Catherine L.

    2015-01-01

    Sex chromosomes are subject to unique evolutionary forces that cause suppression of recombination, leading to sequence degeneration and the formation of heteromorphic chromosome pairs (i.e., XY or ZW). Although progress has been made in characterizing the outcomes of these evolutionary processes on vertebrate sex chromosomes, it is still unclear how recombination suppression and sequence divergence typically occur and how gene dosage imbalances are resolved in the heterogametic sex. The threespine stickleback fish (Gasterosteus aculeatus) is a powerful model system to explore vertebrate sex chromosome evolution, as it possesses an XY sex chromosome pair at relatively early stages of differentiation. Using a combination of whole-genome and transcriptome sequencing, we characterized sequence evolution and gene expression across the sex chromosomes. We uncovered two distinct evolutionary strata that correspond with known structural rearrangements on the Y chromosome. In the oldest stratum, only a handful of genes remain, and these genes are under strong purifying selection. By comparing sex-linked gene expression with expression of autosomal orthologs in an outgroup, we show that dosage compensation has not evolved in threespine sticklebacks through upregulation of the X chromosome in males. Instead, in the oldest stratum, the genes that still possess a Y chromosome allele are enriched for genes predicted to be dosage sensitive in mammals and yeast. Our results suggest that dosage imbalances may have been avoided at haploinsufficient genes by retaining function of the Y chromosome allele through strong purifying selection. PMID:25818858

  13. Demarcation of informative chromosomes in tropical sweet corn inbred lines using microsatellite DNA markers

    Directory of Open Access Journals (Sweden)

    Pedram Kashiani

    2012-01-01

    Full Text Available A study of genetic variation among 10 pairs of chromosomes extracted from 13 tropical sweet corn inbred lines, using 99 microsatellite markers, revealed a wide range of genetic diversity. Allelic richness and the number of effective alleles per chromosome ranged from 2.78 to 4.33 and 1.96 to 3.47, respectively, with respective mean values of 3.62 and 2.73. According to the Shannon's information index (I and Nei's gene diversity coefficient (Nei, Chromosome 10 was the most informative chromosome (I = 1.311 and Nei = 0.703, while Chromosome 2 possessed the least (I = 0.762 and Nei = 0.456. Based on linkage disequilibrium (LD measurements for loci less than 50 cM apart on the same chromosome, all loci on Chromosomes 1, 6 and 7 were in equilibrium. Even so, there was a high proportion of genetic variation in Chromosomes 4, 5, 8, 9 and 10, thereby revealing their appropriateness for use in the genetic diversity investigations among tropical sweet corn lines. Chromosome 4, with the highest number of loci in linkage disequilibrium, was considered the best for marker-phenotype association and QTL mapping, followed by Chromosomes 5, 8, 9 and 10.

  14. Not all hypochondroplasia families are linked to chromosome 4p16.3

    Energy Technology Data Exchange (ETDEWEB)

    Rousseau, F.; Munnich, A.; Merrer, M.Le. [INSERM, Paris (France)] [and others

    1994-09-01

    Achondroplasia (ACH, MIM 100800) and hypochondroplasia (HCH, MIM 146000) are short limb dwarfism with enlarged head sharing some specific radiological features. Inter- and intrafamilial clinical variability and histolopathological aspects of the growth cartilage suggested that ACH and HCH are allelic disorders. Recently, the gene for achondroplasia was mapped to chromosome 4p and no recombinants were found in 9 families with hypochondroplasia between D4S111 and the telomere (Zmax=1.70, {theta}=0). By using an additional polymorphic DNA marker which detects VNTR-like polymorphism at the D4S227 locus and a new microsatellite at locus D4S? (AFM163yc1), we observed recombinant events with markers of the chromosome 4p16.3 in 3/10 hypochondroplasia families, indicating that not all hypochondroplasia families are linked to chromosome 4p. A fibroblast growth factor receptor (FGFR3) expressed in chondrocytes during endochondral ossification which is located in the 2.5 Mb candidate region for achondroplasia was regarded as a good candidate gene. No major rearrangement of the FGFR3 gene was detected by Southern blot analysis using an FGFR3 cDNA probe. Further investigations will be required to conclude as to the possible involvement of this gene in ACH.

  15. Chromosomes 3B and 4D are associated with several milling and baking quality traits in a soft white spring wheat (Triticum aestivum L.) population.

    Science.gov (United States)

    Carter, A H; Garland-Campbell, K; Morris, C F; Kidwell, K K

    2012-04-01

    Wheat is marketed based on end-use quality characteristics and better knowledge of the underlying genetics of specific quality parameters is essential to enhance the breeding process. A set of 188 recombinant inbred lines from a 'Louise' by 'Penawawa' mapping population was grown in two crop years at two locations in the Pacific Northwest region of the United States and data were collected on 17 end-use quality traits using established quality analysis protocols. Using an established genetic linkage map, composite interval mapping was used to identify QTL associated with 16 of the 17 quality traits. QTL were found on 13 of the 21 wheat chromosomes. A large number of QTL were located on chromosomes 3B and 4D and coincided with traits for milling quality and starch functionality. Chromosome 3B contained 10 QTL, which were localized to a 26.2 cM region. Chromosome 4D contained 7 QTL, all of which were located on an 18.8 cM region of this chromosome. The majority of the alleles for superior end-use quality were associated with the cultivar Louise. The identified QTL detected remained highly significant independent of grain yield and protein quantity. The identification of these QTL for end-use quality gives key insight into the relationship and complexity of end-use quality traits. It also improves our understanding of these relationships, thereby allowing plant breeders to make valuable gains from selection for these important traits.

  16. Chromosomal disorders and male infertility

    Institute of Scientific and Technical Information of China (English)

    Gary L Harton; Helen G Tempest

    2012-01-01

    infertility in humans is surprisingly common occurring in approximately 15% of the population wishing to start a family.Despite this,the molecular and genetic factors underlying the cause of infertility remain largely undiscovered.Nevertheless,more and more genetic factors associated with infertility are being identified.This review will focus on our current understanding of the chromosomal basis of male infertility specifically:chromosomal aneuploidy,structural and numerical karyotype abnormalities and Y chromosomal microdeletions.Chromosomal aneuploidy is the leading cause of pregnancy loss and developmental disabilities in humans.Aneuploidy is predominantly maternal in origin,but concerns have been raised regarding the safety of intracytoplasmic sperm injection as infertile men have significantly higher levels of sperm aneuploidy compared to their fertile counterparts.Males with numerical or structural karyotype abnormalities are also at an increased risk of producing aneuploid sperm.Our current understanding of how sperm aneuploidy translates to embryo aneuploidy will be reviewed,as well as the application of preimplantation genetic diagnosis (PGD) in such cases.Clinical recommendations where possible will be made,as well as discussion of the use of emerging array technology in PGD and its potential applications in male infertility.

  17. Chromosomal Evolution in Chiroptera.

    Science.gov (United States)

    Sotero-Caio, Cibele G; Baker, Robert J; Volleth, Marianne

    2017-10-13

    Chiroptera is the second largest order among mammals, with over 1300 species in 21 extant families. The group is extremely diverse in several aspects of its natural history, including dietary strategies, ecology, behavior and morphology. Bat genomes show ample chromosome diversity (from 2n = 14 to 62). As with other mammalian orders, Chiroptera is characterized by clades with low, moderate and extreme chromosomal change. In this article, we will discuss trends of karyotypic evolution within distinct bat lineages (especially Phyllostomidae, Hipposideridae and Rhinolophidae), focusing on two perspectives: evolution of genome architecture, modes of chromosomal evolution, and the use of chromosome data to resolve taxonomic problems.

  18. Chromosomal Evolution in Chiroptera

    Directory of Open Access Journals (Sweden)

    Cibele G. Sotero-Caio

    2017-10-01

    Full Text Available Chiroptera is the second largest order among mammals, with over 1300 species in 21 extant families. The group is extremely diverse in several aspects of its natural history, including dietary strategies, ecology, behavior and morphology. Bat genomes show ample chromosome diversity (from 2n = 14 to 62. As with other mammalian orders, Chiroptera is characterized by clades with low, moderate and extreme chromosomal change. In this article, we will discuss trends of karyotypic evolution within distinct bat lineages (especially Phyllostomidae, Hipposideridae and Rhinolophidae, focusing on two perspectives: evolution of genome architecture, modes of chromosomal evolution, and the use of chromosome data to resolve taxonomic problems.

  19. GREAM: A Web Server to Short-List Potentially Important Genomic Repeat Elements Based on Over-/Under-Representation in Specific Chromosomal Locations, Such as the Gene Neighborhoods, within or across 17 Mammalian Species.

    Directory of Open Access Journals (Sweden)

    Darshan Shimoga Chandrashekar

    Full Text Available Genome-wide repeat sequences, such as LINEs, SINEs and LTRs share a considerable part of the mammalian nuclear genomes. These repeat elements seem to be important for multiple functions including the regulation of transcription initiation, alternative splicing and DNA methylation. But it is not possible to study all repeats and, hence, it would help to short-list before exploring their potential functional significance via experimental studies and/or detailed in silico analyses.We developed the 'Genomic Repeat Element Analyzer for Mammals' (GREAM for analysis, screening and selection of potentially important mammalian genomic repeats. This web-server offers many novel utilities. For example, this is the only tool that can reveal a categorized list of specific types of transposons, retro-transposons and other genome-wide repetitive elements that are statistically over-/under-represented in regions around a set of genes, such as those expressed differentially in a disease condition. The output displays the position and frequency of identified elements within the specified regions. In addition, GREAM offers two other types of analyses of genomic repeat sequences: a enrichment within chromosomal region(s of interest, and b comparative distribution across the neighborhood of orthologous genes. GREAM successfully short-listed a repeat element (MER20 known to contain functional motifs. In other case studies, we could use GREAM to short-list repetitive elements in the azoospermia factor a (AZFa region of the human Y chromosome and those around the genes associated with rat liver injury. GREAM could also identify five over-represented repeats around some of the human and mouse transcription factor coding genes that had conserved expression patterns across the two species.GREAM has been developed to provide an impetus to research on the role of repetitive sequences in mammalian genomes by offering easy selection of more interesting repeats in various

  20. Chromosome mosaicism in hypomelanosis of Ito.

    Science.gov (United States)

    Ritter, C L; Steele, M W; Wenger, S L; Cohen, B A

    1990-01-01

    Our finding of chromosome mosaicism with a ring 22 in a retarded black boy with hypomelanosis of Ito prompted a review of this "syndrome." Most patients have a variety of non-dermal defects, particularly those affecting CNS function. Among karyotyped patients, most are chromosome mosaics of one sort or another. Hypomelanosis of Ito turns out to be a causable non-specific phenotype, i.e., a clinical marker for chromosome mosaicism of all different types in individuals with a dark enough skin to show lighter patches. Consequently, cytogenetic evaluation is indicated in all patients with this skin finding.

  1. Chromosomal Aneuploidy Improves the Brewing Characteristics of Sake Yeast.

    Science.gov (United States)

    Kadowaki, Masafumi; Fujimaru, Yuki; Taguchi, Seiga; Ferdouse, Jannatul; Sawada, Kazutaka; Kimura, Yuta; Terasawa, Yohei; Agrimi, Gennaro; Anai, Toyoaki; Noguchi, Hideki; Toyoda, Atsushi; Fujiyama, Asao; Akao, Takeshi; Kitagaki, Hiroshi

    2017-12-15

    increased mitochondrial activity. This novel discovery will enable the selection of favorable brewery yeasts by monitoring the copy numbers of specific chromosomes through a process that does not involve generation/use of genetically modified organisms. Copyright © 2017 American Society for Microbiology.

  2. Comparison of clinical categories for Escherichia coli harboring specific qnr and chromosomal-mediated fluoroquinolone resistance determinants according to CLSI and EUCAST.

    Science.gov (United States)

    Machuca, Jesús; Briales, Alejandra; Díaz-de-Alba, Paula; Martínez-Martínez, Luis; Rodríguez-Martínez, José-Manuel; Pascual, Álvaro

    2016-03-01

    EUCAST breakpoints are more restrictive than those defined by CLSI. This study highlights the discrepancies between CLSI and EUCAST in a well characterized isogenic Escherichia coli collection and their correlations with specific quinolone resistance mechanisms. The greatest number of discrepancies was observed in strains containing 2-4 resistance mechanisms (MIC values on the borderline of clinical resistance). Bearing in mind that quinolones are concentration dependent antimicrobial agents, small changes in MIC may have relevant consequences for treatment outcomes. Copyright © 2015 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  3. The architecture of chicken chromosome territories changes during differentiation

    Directory of Open Access Journals (Sweden)

    Stadler Sonja

    2004-11-01

    Full Text Available Abstract Background Between cell divisions the chromatin fiber of each chromosome is restricted to a subvolume of the interphase cell nucleus called chromosome territory. The internal organization of these chromosome territories is still largely unknown. Results We compared the large-scale chromatin structure of chromosome territories between several hematopoietic chicken cell types at various differentiation stages. Chromosome territories were labeled by fluorescence in situ hybridization in structurally preserved nuclei, recorded by confocal microscopy and evaluated visually and by quantitative image analysis. Chromosome territories in multipotent myeloid precursor cells appeared homogeneously stained and compact. The inactive lysozyme gene as well as the centromere of the lysozyme gene harboring chromosome located to the interior of the chromosome territory. In further differentiated cell types such as myeloblasts, macrophages and erythroblasts chromosome territories appeared increasingly diffuse, disaggregating to separable substructures. The lysozyme gene, which is gradually activated during the differentiation to activated macrophages, as well as the centromere were relocated increasingly to more external positions. Conclusions Our results reveal a cell type specific constitution of chromosome territories. The data suggest that a repositioning of chromosomal loci during differentiation may be a consequence of general changes in chromosome territory morphology, not necessarily related to transcriptional changes.

  4. Next-generation sequencing technology a new tool for killer cell immunoglobulin-like receptor allele typing in hematopoietic stem cell transplantation.

    Science.gov (United States)

    Maniangou, B; Retière, C; Gagne, K

    2018-02-01

    Killer cell Immunoglobulin-like Receptor (KIR) genes are a family of genes located together within the leukocyte receptor cluster on human chromosome 19q13.4. To date, 17 KIR genes have been identified including nine inhibitory genes (2DL1/L2/L3/L4/L5A/L5B, 3DL1/L2/L3), six activating genes (2DS1/S2/S3/S4/S5, 3DS1) and two pseudogenes (2DP1, 3DP1) classified into group A (KIR A) and group B (KIR B) haplotypes. The number and the nature of KIR genes vary between the individuals. In addition, these KIR genes are known to be polymorphic at allelic level (907 alleles described in July 2017). KIR genes encode for receptors which are predominantly expressed by Natural Killer (NK) cells. KIR receptors recognize HLA class I molecules and are able to kill residual recipient leukemia cells, and thus reduce the likelihood of relapse. KIR alleles of Hematopoietic Stem Cell (HSC) donor would require to be known (Alicata et al. Eur J Immunol 2016) because the KIR allele polymorphism may affect both the KIR + NK cell phenotype and function (Gagne et al. Eur J Immunol 2013; Bari R, et al. Sci Rep 2016) as well as HSCT outcome (Boudreau et al. JCO 2017). The introduction of the Next Generation Sequencing (NGS) has overcome current conventional DNA sequencing method limitations, known to be time consuming. Recently, a novel NGS KIR allele typing approach of all KIR genes was developed by our team in Nantes from 30 reference DNAs (Maniangou et al. Front in Immunol 2017). This NGS KIR allele typing approach is simple, fast, reliable, specific and showed a concordance rate of 95% for centromeric and telomeric KIR genes in comparison with high-resolution KIR typing obtained to those published data using exome capture (Norman PJ et al. Am J Hum Genet 2016). This NGS KIR allele typing approach may also be used in reproduction and to better study KIR + NK cell implication in the control of viral infections. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  5. Allelic variation of bile salt hydrolase genes in Lactobacillus salivarius does not determine bile resistance levels.

    LENUS (Irish Health Repository)

    Fang, Fang

    2009-09-01

    Commensal lactobacilli frequently produce bile salt hydrolase (Bsh) enzymes whose roles in intestinal survival are unclear. Twenty-six Lactobacillus salivarius strains from different sources all harbored a bsh1 allele on their respective megaplasmids. This allele was related to the plasmid-borne bsh1 gene of the probiotic strain UCC118. A second locus (bsh2) was found in the chromosomes of two strains that had higher bile resistance levels. Four Bsh1-encoding allele groups were identified, defined by truncations or deletions involving a conserved residue. In vitro analyses showed that this allelic variation was correlated with widely varying bile deconjugation phenotypes. Despite very low activity of the UCC118 Bsh1 enzyme, a mutant lacking this protein had significantly lower bile resistance, both in vitro and during intestinal transit in mice. However, the overall bile resistance phenotype of this and other strains was independent of the bsh1 allele type. Analysis of the L. salivarius transcriptome upon exposure to bile and cholate identified a multiplicity of stress response proteins and putative efflux proteins that appear to broadly compensate for, or mask, the effects of allelic variation of bsh genes. Bsh enzymes with different bile-degrading kinetics, though apparently not the primary determinants of bile resistance in L. salivarius, may have additional biological importance because of varying effects upon bile as a signaling molecule in the host.

  6. Intrinsic MYH7 expression regulation contributes to tissue level allelic imbalance in hypertrophic cardiomyopathy.

    Science.gov (United States)

    Montag, Judith; Syring, Mandy; Rose, Julia; Weber, Anna-Lena; Ernstberger, Pia; Mayer, Anne-Kathrin; Becker, Edgar; Keyser, Britta; Dos Remedios, Cristobal; Perrot, Andreas; van der Velden, Jolanda; Francino, Antonio; Navarro-Lopez, Francesco; Ho, Carolyn Yung; Brenner, Bernhard; Kraft, Theresia

    2017-08-01

    HCM, the most common inherited cardiac disease, is mainly caused by mutations in sarcomeric genes. More than a third of the patients are heterozygous for mutations in the MYH7 gene encoding for the β-myosin heavy chain. In HCM-patients, expression of the mutant and the wildtype allele can be unequal, thus leading to fractions of mutant and wildtype mRNA and protein which deviate from 1:1. This so-called allelic imbalance was detected in whole tissue samples but also in individual cells. There is evidence that the severity of HCM not only depends on the functional effect of the mutation itself, but also on the fraction of mutant protein in the myocardial tissue. Allelic imbalance has been shown to occur in a broad range of genes. Therefore, we aimed to examine whether the MYH7-alleles are intrinsically expressed imbalanced or whether the allelic imbalance is solely associated with the disease. We compared the expression of MYH7-alleles in non-HCM donors and in HCM-patients with different MYH7-missense mutations. In the HCM-patients, we identified imbalanced as well as equal expression of both alleles. Also at the protein level, allelic imbalance was determined. Most interestingly, we also discovered allelic imbalance and balance in non-HCM donors. Our findings therefore strongly indicate that apart from mutation-specific mechanisms, also non-HCM associated allelic-mRNA expression regulation may account for the allelic imbalance of the MYH7 gene in HCM-patients. Since the relative amount of mutant mRNA and protein or the extent of allelic imbalance has been associated with the severity of HCM, individual analysis of the MYH7-allelic expression may provide valuable information for the prognosis of each patient.

  7. Detecting imbalanced expression of SNP alleles by minisequencing on microarrays

    Directory of Open Access Journals (Sweden)

    Dahlgren Andreas

    2004-10-01

    Full Text Available Abstract Background Each of the human genes or transcriptional units is likely to contain single nucleotide polymorphisms that may give rise to sequence variation between individuals and tissues on the level of RNA. Based on recent studies, differential expression of the two alleles of heterozygous coding single nucleotide polymorphisms (SNPs may be frequent for human genes. Methods with high accuracy to be used in a high throughput setting are needed for systematic surveys of expressed sequence variation. In this study we evaluated two formats of multiplexed, microarray based minisequencing for quantitative detection of imbalanced expression of SNP alleles. We used a panel of ten SNPs located in five genes known to be expressed in two endothelial cell lines as our model system. Results The accuracy and sensitivity of quantitative detection of allelic imbalance was assessed for each SNP by constructing regression lines using a dilution series of mixed samples from individuals of different genotype. Accurate quantification of SNP alleles by both assay formats was evidenced for by R2 values > 0.95 for the majority of the regression lines. According to a two sample t-test, we were able to distinguish 1–9% of a minority SNP allele from a homozygous genotype, with larger variation between SNPs than between assay formats. Six of the SNPs, heterozygous in either of the two cell lines, were genotyped in RNA extracted from the endothelial cells. The coefficient of variation between the fluorescent signals from five parallel reactions was similar for cDNA and genomic DNA. The fluorescence signal intensity ratios measured in the cDNA samples were compared to those in genomic DNA to determine the relative expression levels of the two alleles of each SNP. Four of the six SNPs tested displayed a higher than 1.4-fold difference in allelic ratios between cDNA and genomic DNA. The results were verified by allele-specific oligonucleotide hybridisation and

  8. Qualitative analysis of mouse specific-locus mutations: information on genetic organization, gene expression, and the chromosomal nature of induced lesions

    International Nuclear Information System (INIS)

    Russell, L.B.

    1982-01-01

    Analysis of mouse specific-locus (SL) mutations at three loci has identified over 33 distinct complementation groups - most of which are probably overlapping deficiencies - and 13 to 14 new functional units. The complementation maps that have been generated for the d-se and c regions include numerous vital functions; however, some of the genes in these regions are non-vital. At such loci, hypomorphic mutants must represent intragenic alterations, and some viable nulls could conceivably be intragenic lesions also. Analysis of SL mutations has provided information on genetic expression. Homozygous deficiencies can be completely viable or can kill at any one of a range of developmental stages. Heterozygonus deficiencies of up to 6 cM or more in genetic length have been recovered and propagated. The time of death of homozygous and the degree of inviability of heterozygous deficiencies are related more to specific content of the missing segment than to its length. Combinations of deficiencies with x-autosome translocations that inactivate the homologous region in a mosaic fashion have shown that organismic lethals are not necessarily cell lethal. The spectrum of mutations induced depends on the nature of the mutagen and the type of germ cell exposed. Radiation of spermatogonia produces intragenic as well as null mutations. Spontaneous mutations have an admixture of types not present in populations of mutations induced in germ cells, and this raises doubts concerning the accuracy of doubling-dose calculations in genetic risk estimation. The analysis of SL mutations has yielded genetic tools for the construction of detailed gene-dosage series, cis-trans comparisons, the mapping of known genes and identification of new genes, genetic rescue of various types, and the identification and isolation of DNA sequences

  9. Delimiting the origin of a B chromosome by FISH mapping, chromosome painting and DNA sequence analysis in Astyanax paranae (Teleostei, Characiformes.

    Directory of Open Access Journals (Sweden)

    Duílio M Z de A Silva

    Full Text Available Supernumerary (B chromosomes have been shown to contain a wide variety of repetitive sequences. For this reason, fluorescent in situ hybridisation (FISH is a useful tool for ascertaining the origin of these genomic elements, especially when combined with painting from microdissected B chromosomes. In order to investigate the origin of B chromosomes in the fish species Astyanax paranae, these two approaches were used along with PCR amplification of specific DNA sequences obtained from the B chromosomes and its comparison with those residing in the A chromosomes. Remarkably, chromosome painting with the one-arm metacentric B chromosome probe showed hybridization signals on entire B chromosome, while FISH mapping revealed the presence of H1 histone and 18S rDNA genes symmetrically placed in both arms of the B chromosome. These results support the hypothesis that the B chromosome of A. paranae is an isochromosome. Additionally, the chromosome pairs Nos. 2 or 23 are considered the possible B chromosome ancestors since both contain syntenic H1 and 18S rRNA sequences. The analysis of DNA sequence fragments of the histone and rRNA genes obtained from the microdissected B chromosomes showed high similarity with those obtained from 0B individuals, which supports the intraspecific origin of B chromosomes in A. paranae. Finally, the population hereby analysed showed a female-biased B chromosome presence suggesting that B chromosomes in this species could influence sex determinism.

  10. Discrimination of chromosome by autoradiography

    International Nuclear Information System (INIS)

    Masubuchi, Masanori

    1975-01-01

    This paper describes discrimination of chromosome by autoradiography. In this method, the difference in DNA synthetic phase between each chromosome was used as a standard, and the used chromosome was in metaphase, as morphological characteristics were markedly in this phase. Cell cycle and autoradiography with 3 H-thymidine were also examined. In order to discriminate chromosome by autoradiography, it was effective to utilize the labelled pattern in late DNA synthetic phase, where asynchronous replication of chromosome appeared most obviously. DNA synthesis in chromosome was examined in each DNA synthetic phase by culturing the chromosome after the treatment with 3 H-thymidine and altering the time to prepare chromosome specimen. Discrimination of chromosome in plants and animals by autoradiography was also mentioned. It was noticed as a structural and functional discrimination of chromosome to observe amino acid uptake into chromosome protein and to utilize the difference in labelled pattern between the sites of chromosome. (K. Serizawa)

  11. Fetal chromosome analysis

    DEFF Research Database (Denmark)

    Philip, J; Tabor, A; Bang, J

    1983-01-01

    The aim of the study was to investigate the rationale of the current indications for fetal chromosome analysis. 5372 women had 5423 amniocentesis performed, this group constituting a consecutive sample at the chromosome laboratory, Rigshospitalet, Copenhagen from March 1973 to September 1980 (Group...... A + B). Pregnant women 35 years of age, women who previously had a chromosomally abnormal child, families with translocation carriers or other heritable chromosomal disease, families where the father was 50 years or more and women in families with a history of Down's syndrome (group A), were compared...... to women having amniocentesis, although considered not to have any increased risk of fetal chromosome abnormality (1390 pregnancies, group B). They were also compared with 750 consecutive pregnancies in women 25-34 years of age, in whom all heritable diseases were excluded (group C). The risk of unbalanced...

  12. Differential allelic expression of a fibrillin gene (FBNI) in patients with Marfan syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Hewett, D.; Lynch, J.; Sykes, B. [Univ. of Oxford (United Kingdom); Firth, H. [Churchill Hospital, Oxford (United Kingdom); Child, A. [St. George`s Hospital Medical School, London (United Kingdom)

    1994-09-01

    Marfan syndrome is a connective-tissue disorder affecting cardiovascular, skeletal, and ocular systems. The major Marfan locus has been identified as the FBN1 gene on chromosome 15; this codes for the extracellular-matrix protein fibrillin, a 350-kD constituent of the 8-10-nm elastin-associated microfibrils. The authors identified five MFS patients who were heterozygous for an RsaI restriction-site dimorphism in the 3{prime} UTR of the FBN1 gene. This expressed variation was used to distinguish the mRNA output from each of the two FBN1 alleles in fibroblast cultures from these five patients. Three of the patients were shown to produce <5% of the normal level of FBN1 transcripts from one of their alleles. This null-allele phenotype was not observed in 10 nonmarfanoid fibroblast cell lines. 26 refs., 4 figs.

  13. Microsatellite D21D210 (GT-12) allele frequencies in sporadic Alzheimer's disease

    International Nuclear Information System (INIS)

    Lannfelt, L.; Lilius, L.; Viitanen, M.; Winblad, B.; Basun, H.; Houlden, H.; Rossor, M.; Hardy, J.

    1995-01-01

    Four disease-causing mutations have so far been described in the amyloid precursor protein gene on chromosome 21 in familial early-onset Alzheimer's disease. Linkage analysis with a fourteen-allele microsatellite at D21S210 named GT-12 has proven useful in the elucidation of amyloid presursor protein gene involvement in Alzheimer's disease families, as it is closely linked to the gene. Most cases of Alzheimer's disease are thought to be sporadic and not familial. However, evidence from earlier studies suggests an important genetic contribution also in sporadic cases, where gene-environment interaction may contribute to the disease. We have determined frequencies of the GT-12 alleles in 78 Swedish and 49 British sporadic Alzheimer's disease cases and 104 healthy elderly control subjects, to investigate if the disease associates with a particular genotype in GT-12. However, no differences in allele frequencies were observed between any of the groups. (au) (26 refs.)

  14. The frequency of allelic lethals and complementation maps in natural populations of drosophila melanogaster from Mexico

    Directory of Open Access Journals (Sweden)

    Salceda Victor M.

    2004-01-01

    Full Text Available Departing from a previous study on the genetic loads affecting the second chromosome of Drosophila melanogaster in four natural populations, 171 lethal chromosomes were recovered and maintained as a balanced stocks in the condition Cy L / 1 (l=lethal; of those lethais 24 correspond to population A, 50 to populations B and C and 47 to population D. later on an intra-population allelism test for the four populations was performed for each one. A total of 3807 inter lethal crosses were done yielding a total of i 10 allelic combinations, from them the respective percentage of allelism for each population was calculated and they are as follow: 3.98 % for population A, 1.80 % for population B, 3.67 % for population C and 2.96 % for population D. the observed values for the frequency of allelism in these populations are not significantly different from those reported by other authors in similar studies in natural and/or experimental populations. Beside these values the frequency for singles, doubles, triplets and even quadruplets present in each population were determined, they shown the presence of various complementation maps due to the clustering of few different lethals: also a large complementation map formed by a large cluster involving the presence of 26 different lethals found in population D all of them combined constituting a single unit was found.

  15. Mapping to mouse chromosome 3 of the gene encoding latexin (Lxn) expressed in neocortical neurons in a region-specific manner

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Ming-hao; Uratani, Yoshihiko; Arimatsu, Yasuyoshi [Mitsubishi Kasei Institute of Life Sciences, Tokyo (Japan)

    1997-02-01

    Latexin was first found as a 29-kDa antigen expressed in a subset of neurons in infragranular layers of lateral, but not dorsal, neocortical areas in the rat using a monoclonal antibody PC3.1. It was found that the vast majority of latexin-expressing neurons in both layers V and VI within the lateral neocortex were generated concurrently at Embryonic Day 15, demonstrating a strict correlation between the molecular identity of neurons and the time of their generation. Since neurons expressing latexin are located in the restricted part of the neocortex, latexin has been used as a useful molecular marker to elucidate the mechanism underlying cortical regional specification. The latexin cDNA isolated from a cDNA library of the rat cerebral cortex encodes a protein composed of 223-amino-acid residues containing two potential Ca{sup 2+}/calmodulin-dependent protein kinase sites and one cGMP-dependent protein kinase phosphorylation site. The absence of any signal peptide or potential transmembrane domain is consistent with the apparent cytosolic localization of latexin in the rat brain. The transcripts of latexin were expressed in not only neutral but also nonneural tissues (e.g., lung, spleen, kidney, heart, and digestive tracts). Recently, it has been demonstrated that latexin purified from the rat brain has inhibitory activity against carboxypeptidase A1, carboxypeptidase A2, and mast cell carboxypeptidase A, with less carboxypeptidase B-inhibiting activity. The amino acid sequence deduced from the rat latexin cDNA has no strict homology to any sequences so far known. Genomic Southern blot analysis using a cDNA probe of rat latexin suggested that the gene encoding latexin in the rat has homologues in other mammalian species and in the chicken, but not in the nematode, fly, or frog. 9 refs., 1 fig.

  16. Chromosome identification by new molecular markers and genomic in situ hybridization in the Triticum-Secale-Thinopyrum trigeneric hybrids.

    Science.gov (United States)

    Dai, Yi; Duan, Yamei; Chi, Dawn; Liu, Huiping; Huang, Shuai; Cao, Wenguang; Gao, Yong; Fedak, George; Chen, Jianmin

    2017-08-01

    It is very important to use chromosome-specific markers for identifying alien chromosomes in advanced generations of distant hybridization. The chromosome-specific markers of rye and Thinopyrum elongatum, as well as genomic in situ hybridization, were used to identify the alien chromosomes in eight lines that were derived from the crossing between Triticum trititrigia (AABBEE) and triticale (AABBRR). The results showed that four lines contained all rye chromosomes but no Th. elongatum chromosomes. The line RE36-1 contained all of the rye chromosomes except for chromosome 2R. The lines RE33-2 and RE62-1 contained all rye chromosomes and 1E and 5E translocated chromosome, respectively. The line RE24-4 contained 12 rye chromosomes plus a 7E chromosome or 12 rye chromosomes plus one R-E translocated chromosome. Chromosome identification in the above lines was consistent using chromosome-specific markers and genomic in situ hybridization. These chromosome-specific markers provide useful tools for detecting alien chromosomes in trigeneric hybrids, and these lines could be utilized as valuable germplasm in wheat improvement.

  17. CYP3A4 allelic variants with amino acid substitutions in exons 7 and 12: evidence for an allelic variant with altered catalytic activity.

    Science.gov (United States)

    Sata, F; Sapone, A; Elizondo, G; Stocker, P; Miller, V P; Zheng, W; Raunio, H; Crespi, C L; Gonzalez, F J

    2000-01-01

    To determine the existence of mutant and variant CgammaP3A4 alleles in three racial groups and to assess functions of the variant alleles by complementary deoxyribonucleic acid (cDNA) expression. A bacterial artificial chromosome that contains the complete CgammaP3A4 gene was isolated and the exons and surrounding introns were directly sequenced to develop primers to polymerase chain reaction (PCR) amplify and sequence the gene from lymphocyte DNA. DNA samples from Chinese, black, and white subjects were screened. Mutating the affected amino acid in the wild-type cDNA and expressing the variant enzyme with use of the baculovirus system was used to functionally evaluate the variant allele having a missense mutation. To investigate the existence of mutant and variant CgammaP3A4 alleles in humans, all 13 exons and the 5'-flanking region of the human CgammaP3A4 gene in three racial groups were sequenced and four alleles were identified. An A-->G point mutation in the 5'-flanking region of the human CgammaP3A4 gene, designated CgammaP3A4*1B, was found in the three different racial groups. The frequency of this allele in a white population was 4.2%, whereas it was 66.7% in black subjects. The CgammaP3A4*1B allele was not found in Chinese subjects. A second variant allele, designated CgammaP3A4*2, having a Ser222Pro change, was found at a frequency of 2.7% in the white population and was absent in the black subjects and Chinese subjects analyzed. Baculovirus-directed cDNA expression revealed that the CYP3A4*2 P450 had a lower intrinsic clearance for the CYP3A4 substrate nifedipine compared with the wild-type enzyme but was not significantly different from the wild-type enzyme for testosterone 6beta-hydroxylation. Another rare allele, designated CgammaP3A4*3, was found in a single Chinese subject who had a Met445Thr change in the conserved heme-binding region of the P450. These are the first examples of potential function polymorphisms resulting from missense mutations in

  18. Chromosomal aberrations in benign prostatic hyperplasia patients

    Directory of Open Access Journals (Sweden)

    Muammer Altok

    2016-01-01

    Full Text Available Purpose: To investigate the chromosomal changes in patients with benign prostatic hyperplasia (BPH. Materials and Methods: A total of 54 patients diagnosed with clinical BPH underwent transurethral prostate resection to address their primary urological problem. All patients were evaluated by use of a comprehensive medical history and rectal digital examination. The preoperative evaluation also included serum prostate-specific antigen (PSA measurement and ultrasonographic measurement of prostate volume. Prostate cancer was detected in one patient, who was then excluded from the study. We performed conventional cytogenetic analyses of short-term cultures of 53 peripheral blood samples obtained from the BPH patients. Results: The mean (±standard deviation age of the 53 patients was 67.8±9.4 years. The mean PSA value of the patients was 5.8±7.0 ng/mL. The mean prostate volume was 53.6±22.9 mL. Chromosomal abnormalities were noted in 5 of the 53 cases (9.4%. Loss of the Y chromosome was the most frequent chromosomal abnormality and was observed in three patients (5.7%. There was no statistically significant relationship among age, PSA, prostate volume, and chromosomal changes. Conclusions: Loss of the Y chromosome was the main chromosomal abnormality found in our study. However, this coexistence did not reach a significant level. Our study concluded that loss of the Y chromosome cannot be considered relevant for the diagnosis of BPH as it is for prostate cancer. Because BPH usually occurs in aging men, loss of the Y chromosome in BPH patients may instead be related to the aging process.

  19. Y-chromosome phylogeny in the evolutionary net of chamois (genus Rupicapra

    Directory of Open Access Journals (Sweden)

    Domínguez Ana

    2011-09-01

    Full Text Available Abstract Background The chamois, distributed over most of the medium to high altitude mountain ranges of southern Eurasia, provides an excellent model for exploring the effects of historical and evolutionary events on diversification. Populations have been grouped into two species, Rupicapra pyrenaica from southwestern Europe and R. rupicapra from eastern Europe. The study of matrilineal mitochondrial DNA (mtDNA and biparentally inherited microsatellites showed that the two species are paraphyletic and indicated alternate events of population contraction and dispersal-hybridization in the diversification of chamois. Here we investigate the pattern of variation of the Y-chromosome to obtain information on the patrilineal phylogenetic position of the genus Rupicapra and on the male-specific dispersal of chamois across Europe. Results We analyzed the Y-chromosome of 87 males covering the distribution range of the Rupicapra genus. We sequenced a fragment of the SRY gene promoter and characterized the male specific microsatellites UMN2303 and SRYM18. The SRY promoter sequences of two samples of Barbary sheep (Ammotragus lervia were also determined and compared with the sequences of Bovidae available in the GenBank. Phylogenetic analysis of the alignment showed the clustering of Rupicapra with Capra and the Ammotragus sequence obtained in this study, different from the previously reported sequence of Ammotragus which groups with Ovis. Within Rupicapra, the combined data define 10 Y-chromosome haplotypes forming two haplogroups, which concur with taxonomic classification, instead of the three clades formed for mtDNA and nuclear microsatellites. The variation shows a west-to-east geographical cline of ancestral to derived alleles. Conclusions The phylogeny of the SRY-promoter shows an association between Rupicapra and Capra. The position of Ammotragus needs a reinvestigation. The study of ancestral and derived characters in the Y-chromosome suggests

  20. Sex chromosomes and speciation in birds and other ZW systems.

    Science.gov (United States)

    Irwin, Darren E

    2018-02-14

    Theory and empirical patterns suggest a disproportionate role for sex chromosomes in evolution and speciation. Focusing on ZW sex determination (females ZW, males ZZ; the system in birds, many snakes, and lepidopterans), I review how evolutionary dynamics are expected to differ between the Z, W and the autosomes, discuss how these differences may lead to a greater role of the sex chromosomes in speciation and use data from birds to compare relative evolutionary rates of sex chromosomes and autosomes. Neutral mutations, partially or completely recessive beneficial mutations, and deleterious mutations under many conditions are expected to accumulate faster on the Z than on autosomes. Sexually antagonistic polymorphisms are expected to arise on the Z, raising the possibility of the spread of preference alleles. The faster accumulation of many types of mutations and the potential for complex evolutionary dynamics of sexually antagonistic traits and preferences contribute to a role for the Z chromosome in speciation. A quantitative comparison among a wide variety of bird species shows that the Z tends to have less within-population diversity and greater between-species differentiation than the autosomes, likely due to both adaptive evolution and a greater rate of fixation of deleterious alleles. The W chromosome also shows strong potential to be involved in speciation, in part because of its co-inheritance with the mitochondrial genome. While theory and empirical evidence suggest a disproportionate role for sex chromosomes in speciation, the importance of sex chromosomes is moderated by their small size compared to the whole genome. © 2018 John Wiley & Sons Ltd.

  1. Non-disjunction of chromosome 13

    DEFF Research Database (Denmark)

    Bugge, Merete; Collins, Andrew; Hertz, Jens Michael

    2007-01-01

    We performed a molecular study with 21 microsatellites on a sample of 82 trisomy 13 conceptuses, the largest number of cases studied to date. The parental origin was determined in every case and in 89% the extra chromosome 13 was of maternal origin with an almost equal number of maternal MI and MII...... recombination in both maternal MI and MII errors and the former is associated with a significant number of tetrads (33%) that are nullichiasmate, which do not appear to be a feature of normal chromosome 13 meiosis. This study supports the evidence for subtle chromosome-specific influences on the mechanisms...... that determine non-disjunction of human chromosomes, consistent with the diversity of findings for other trisomies. Udgivelsesdato: 2007-Aug-15...

  2. Improvements to a Markerless Allelic Exchange System for Bacillus anthracis.

    Directory of Open Access Journals (Sweden)

    Roger D Plaut

    Full Text Available A system was previously developed for conducting I-SceI-mediated allelic exchange in Bacillus anthracis. In this system, recombinational loss of a chromosomally-integrated allelic exchange vector is stimulated by creation of a double-stranded break within the vector by the homing endonuclease I-SceI. Although this system is reasonably efficient and represents an improvement in the tools available for allelic exchange in B. anthracis, researchers are nonetheless required to "pick and patch" colonies in order to identify candidate "exchangeants." In the present study, a number of improvements have been made to this system: 1 an improved I-SceI-producing plasmid includes oriT so that both plasmids can now be introduced by conjugation, thus avoiding the need for preparing electro-competent cells of each integration intermediate; 2 antibiotic markers have been changed to allow the use of the system in select agent strains; and 3 both plasmids have been marked with fluorescent proteins, allowing the visualization of plasmid segregation on a plate and obviating the need for "picking and patching." These modifications have made the process easier, faster, and more efficient, allowing for parallel construction of larger numbers of mutant strains. Using this improved system, the genes encoding the tripartite anthrax toxin were deleted singly and in combination from plasmid pXO1 of Sterne strain 34F2. In the course of this study, we determined that DNA transfer to B. anthracis could be accomplished by conjugation directly from a methylation-competent E. coli strain.

  3. Exploring new alleles for frost tolerance in winter rye.

    Science.gov (United States)

    Erath, Wiltrud; Bauer, Eva; Fowler, D Brian; Gordillo, Andres; Korzun, Viktor; Ponomareva, Mira; Schmidt, Malthe; Schmiedchen, Brigitta; Wilde, Peer; Schön, Chris-Carolin

    2017-10-01

    Rye genetic resources provide a valuable source of new alleles for the improvement of frost tolerance in rye breeding programs. Frost tolerance is a must-have trait for winter cereal production in northern and continental cropping areas. Genetic resources should harbor promising alleles for the improvement of frost tolerance of winter rye elite lines. For frost tolerance breeding, the identification of quantitative trait loci (QTL) and the choice of optimum genome-based selection methods are essential. We identified genomic regions involved in frost tolerance of winter rye by QTL mapping in a biparental population derived from a highly frost tolerant selection from the Canadian cultivar Puma and the European elite line Lo157. Lines per se and their testcrosses were phenotyped in a controlled freeze test and in multi-location field trials in Russia and Canada. Three QTL on chromosomes 4R, 5R, and 7R were consistently detected across environments. The QTL on 5R is congruent with the genomic region harboring the Frost resistance locus 2 (Fr-2) in Triticeae. The Puma allele at the Fr-R2 locus was found to significantly increase frost tolerance. A comparison of predictive ability obtained from the QTL-based model with different whole-genome prediction models revealed that besides a few large, also small QTL effects contribute to the genomic variance of frost tolerance in rye. Genomic prediction models assigning a high weight to the Fr-R2 locus allow increasing the selection intensity for frost tolerance by genome-based pre-selection of promising candidates.

  4. Evolutionary stability of sex chromosomes in snakes.

    Science.gov (United States)

    Rovatsos, Michail; Vukić, Jasna; Lymberakis, Petros; Kratochvíl, Lukáš

    2015-12-22

    Amniote vertebrates possess various mechanisms of sex determination, but their variability is not equally distributed. The large evolutionary stability of sex chromosomes in viviparous mammals and birds was believed to be connected with their endothermy. However, some ectotherm lineages seem to be comparably conserved in sex determination, but previously there was a lack of molecular evidence to confirm this. Here, we document a stability of sex chromosomes in advanced snakes based on the testing of Z-specificity of genes using quantitative PCR (qPCR) across 37 snake species (our qPCR technique is suitable for molecular sexing in potentially all advanced snakes). We discovered that at least part of sex chromosomes is homologous across all families of caenophidian snakes (Acrochordidae, Xenodermatidae, Pareatidae, Viperidae, Homalopsidae, Colubridae, Elapidae and Lamprophiidae). The emergence of differentiated sex chromosomes can be dated back to about 60 Ma and preceded the extensive diversification of advanced snakes, the group with more than 3000 species. The Z-specific genes of caenophidian snakes are (pseudo)autosomal in the members of the snake families Pythonidae, Xenopeltidae, Boidae, Erycidae and Sanziniidae, as well as in outgroups with differentiated sex chromosomes such as monitor lizards, iguanas and chameleons. Along with iguanas, advanced snakes are therefore another example of ectothermic amniotes with a long-term stability of sex chromosomes comparable with endotherms. © 2015 The Author(s).

  5. CHROMOSOMES OF WOODY SPECIES

    Directory of Open Access Journals (Sweden)

    Julio R Daviña

    2000-01-01

    Full Text Available Chromosome numbers of nine subtropical woody species collected in Argentina and Paraguay are reported. The counts tor Coutarea hexandra (2n=52, Inga vera subsp. affinis 2n=26 (Fabaceae and Chorisia speciosa 2n=86 (Bombacaceae are reported for the first time. The chromosome number given for Inga semialata 2n=52 is a new cytotype different from the previously reported. Somatic chromosome numbers of the other taxa studied are: Sesbania punicea 2n=12, S. virgata 2n=12 and Pilocarpus pennatifolius 2n=44 from Argentina

  6. Reduced Height (Rht Alleles Affect Wheat Grain Quality.

    Directory of Open Access Journals (Sweden)

    Richard Casebow

    Full Text Available The effects of dwarfing alleles (reduced height, Rht in near isogenic lines on wheat grain quality are characterised in field experiments and related to effects on crop height, grain yield and GA-sensitivity. Alleles included those that conferred GA-insensitivity (Rht-B1b, Rht-B1c, Rht-D1b, Rht-D1c as well as those that retained GA-sensitivity (rht(tall, Rht8, Rht8 + Ppd-D1a, Rht12. Full characterisation was facilitated by including factors with which the effects of Rht alleles are known to interact for grain yield (i.e. system, [conventional or organic]; tillage intensity [plough-based, minimum or zero]; nitrogen fertilizer level [0-450 kg N/ha]; and genetic backgrounds varying in height [cvs Maris Huntsman, Maris Widgeon, and Mercia]. Allele effects on mean grain weight and grain specific weight were positively associated with final crop height: dwarfing reduced these quality criteria irrespective of crop management or GA-sensitivity. In all but two experiments the effects of dwarfing alleles on grain nitrogen and sulphur concentrations were closely and negatively related to effects on grain yield, e.g. a quadratic relationship between grain yield and crop height manipulated by the GA-insensitive alleles was mirrored by quadratic relationships for nitrogen and sulphur concentrations: the highest yields and most dilute concentrations occurred around 80cm. In one of the two exceptional experiments the GA-insensitive Rht-B1b and Rht-B1c significantly (P<0.05 reduced grain nitrogen concentration in the absence of an effect on yield, and in the remaining experiment the GA-sensitive Rht8 significantly reduced both grain yield and grain nitrogen concentration simultaneously. When Rht alleles diluted grain nitrogen concentration, N:S ratios and SDS-sedimentation volumes were often improved. Hagberg falling number (HFN was negatively related to crop height but benefits from dwarfing were only seen for GA-insensitive alleles. For HFN, therefore, there

  7. Reduced Height (Rht) Alleles Affect Wheat Grain Quality.

    Science.gov (United States)

    Casebow, Richard; Hadley, Caroline; Uppal, Rajneet; Addisu, Molla; Loddo, Stefano; Kowalski, Ania; Griffiths, Simon; Gooding, Mike

    2016-01-01

    The effects of dwarfing alleles (reduced height, Rht) in near isogenic lines on wheat grain quality are characterised in field experiments and related to effects on crop height, grain yield and GA-sensitivity. Alleles included those that conferred GA-insensitivity (Rht-B1b, Rht-B1c, Rht-D1b, Rht-D1c) as well as those that retained GA-sensitivity (rht(tall), Rht8, Rht8 + Ppd-D1a, Rht12). Full characterisation was facilitated by including factors with which the effects of Rht alleles are known to interact for grain yield (i.e. system, [conventional or organic]; tillage intensity [plough-based, minimum or zero]; nitrogen fertilizer level [0-450 kg N/ha]; and genetic backgrounds varying in height [cvs Maris Huntsman, Maris Widgeon, and Mercia]. Allele effects on mean grain weight and grain specific weight were positively associated with final crop height: dwarfing reduced these quality criteria irrespective of crop management or GA-sensitivity. In all but two experiments the effects of dwarfing alleles on grain nitrogen and sulphur concentrations were closely and negatively related to effects on grain yield, e.g. a quadratic relationship between grain yield and crop height manipulated by the GA-insensitive alleles was mirrored by quadratic relationships for nitrogen and sulphur concentrations: the highest yields and most dilute concentrations occurred around 80cm. In one of the two exceptional experiments the GA-insensitive Rht-B1b and Rht-B1c significantly (Pgrain nitrogen concentration in the absence of an effect on yield, and in the remaining experiment the GA-sensitive Rht8 significantly reduced both grain yield and grain nitrogen concentration simultaneously. When Rht alleles diluted grain nitrogen concentration, N:S ratios and SDS-sedimentation volumes were often improved. Hagberg falling number (HFN) was negatively related to crop height but benefits from dwarfing were only seen for GA-insensitive alleles. For HFN, therefore, there was the strongest evidence for

  8. AFLP diversity between the Novosibirsk and Tomsk chromosome races of the common shrew (Sorex araneus

    Directory of Open Access Journals (Sweden)

    Andrey Polyakov

    2009-12-01

    Full Text Available Genetic diversity between of the Novosibirsk and Tomsk chromosome races of the common shrew (Sorex araneus was analyzed using 39 polymorphic AFLP (amplified fragments length polymorphism markers. Exact and F-statistics tests for population differentiation demonstrated significant interracial difference in allele frequencies and significant subdivision between the races. The value of the genetic distance between the chromosome races observed in this study corresponds to that found between subspecies of mammals studied so far.

  9. Roles of the Y chromosome genes in human cancers

    Directory of Open Access Journals (Sweden)

    Tatsuo Kido

    2015-06-01

    Full Text Available Male and female differ genetically by their respective sex chromosome composition, that is, XY as male and XX as female. Although both X and Y chromosomes evolved from the same ancestor pair of autosomes, the Y chromosome harbors male-specific genes, which play pivotal roles in male sex determination, germ cell differentiation, and masculinization of various tissues. Deletions or translocation of the sex-determining gene, SRY, from the Y chromosome causes disorders of sex development (previously termed as an intersex condition with dysgenic gonads. Failure of gonadal development results not only in infertility, but also in increased risks of germ cell tumor (GCT, such as gonadoblastoma and various types of testicular GCT. Recent studies demonstrate that either loss of Y chromosome or ectopic expression of Y chromosome genes is closely associated with various male-biased diseases, including selected somatic cancers. These observations suggest that the Y-linked genes are involved in male health and diseases in more frequently than expected. Although only a small number of protein-coding genes are present in the male-specific region of Y chromosome, the impacts of Y chromosome genes on human diseases are still largely unknown, due to lack of in vivo models and differences between the Y chromosomes of human and rodents. In this review, we highlight the involvement of selected Y chromosome genes in cancer development in men.

  10. Chromosome length scaling in haploid, asexual reproduction

    International Nuclear Information System (INIS)

    Oliveira, P M C de

    2007-01-01

    We study the genetic behaviour of a population formed by haploid individuals which reproduce asexually. The genetic information for each individual is stored along a bit-string (or chromosome) with L bits, where 0-bits represent the wild allele and 1-bits correspond to harmful mutations. Each newborn inherits this chromosome from its parent with a few random mutations: on average a fixed number m of bits are flipped. Selection is implemented according to the number N of 1-bits counted along the individual's chromosome: the smaller N the higher the probability an individual has to survive a new time step. Such a population evolves, with births and deaths, and its genetic distribution becomes stabilized after sufficiently many generations have passed. The question we pose concerns the procedure of increasing L. The aim is to get the same distribution of genetic loads N/L among the equilibrated population, in spite of a larger L. Should we keep the same mutation rate m/L for different values of L? The answer is yes, which intuitively seems to be plausible. However, this conclusion is not trivial, according to our simulation results: the question also involves the population size

  11. Chromosomal abnormalities and autism

    Directory of Open Access Journals (Sweden)

    Farida El-Baz

    2016-01-01

    Conclusion: Chromosomal abnormalities were not detected in the studied autistic children, and so the relation between the genetics and autism still needs further work up with different study methods and techniques.

  12. Chromosome condensation and segmentation

    International Nuclear Information System (INIS)

    Viegas-Pequignot, E.M.

    1981-01-01

    Some aspects of chromosome condensation in mammalians -humans especially- were studied by means of cytogenetic techniques of chromosome banding. Two further approaches were adopted: a study of normal condensation as early as prophase, and an analysis of chromosome segmentation induced by physical (temperature and γ-rays) or chemical agents (base analogues, antibiotics, ...) in order to show out the factors liable to affect condensation. Here 'segmentation' means an abnormal chromosome condensation appearing systematically and being reproducible. The study of normal condensation was made possible by the development of a technique based on cell synchronization by thymidine and giving prophasic and prometaphasic cells. Besides, the possibility of inducing R-banding segmentations on these cells by BrdU (5-bromodeoxyuridine) allowed a much finer analysis of karyotypes. Another technique was developed using 5-ACR (5-azacytidine), it allowed to induce a segmentation similar to the one obtained using BrdU and identify heterochromatic areas rich in G-C bases pairs [fr

  13. Gonadal sex chromosome complement in individuals with sex chromosomal and/or gonadal disorders

    Energy Technology Data Exchange (ETDEWEB)

    Bridge, J.A.; Sanger, W.G.; Seemayer, T. [Univ. of Nebraska Medical Center, Omaha, NE (United States)] [and others

    1994-09-01

    Gonadal abnormalities are characteristically seen in patients with sex chromosomal aneuploidy. Morphologically these abnormalities can be variable and are hypothesized to be dependent on the sex chromosomal consititution of the gonad (independent of the chromosomal complement of other tissues, such as peripheral blood lymphocytes). In this study, the gonadal sex chromosome complement was evaluated for potential mosaicism and correlated with the histopathology from 5 patients with known sex chromosomal and/or gonadal disorders. FISH techniques using X and Y chromosome specific probes were performed on nuclei extracted from paraffin embedded tissue. Gonadal tissue obtained from case 1 (a true hemaphroditic newborn) consisted of ovotestes and epididymis (left side) and ovary with fallopian tube (right side). Cytogenetic and FISH studies performed on blood, ovotestes and ovary revealed an XX complement. Cytogenetic analysis of blood from case 2, a 4-year-old with suspected Turner syndrome revealed 45,X/46,X,del(Y)(q11.21). FISH analysis of the resected gonads (histologically = immature testes) confirmed an X/XY mosaic complement. Histologically, the gonadal tissue was testicular. Severe autolysis prohibited successful analysis in the 2 remaining cases. In summary, molecular cytogenetic evaluation of gonadal tissue from individuals with sex chromosomal and/or gonadal disorders did not reveal tissue-specific anomalies which could account for differences observed pathologically.

  14. YBR/EiJ mice: a new model of glaucoma caused by genes on chromosomes 4 and 17

    Directory of Open Access Journals (Sweden)

    K. Saidas Nair

    2016-08-01

    Full Text Available A variety of inherited animal models with different genetic causes and distinct genetic backgrounds are needed to help dissect the complex genetic etiology of glaucoma. The scarcity of such animal models has hampered progress in glaucoma research. Here, we introduce a new inherited glaucoma model: the inbred mouse strain YBR/EiJ (YBR. YBR mice develop a form of pigmentary glaucoma. They exhibit a progressive age-related pigment-dispersing iris disease characterized by iris stromal atrophy. Subsequently, these mice develop elevated intraocular pressure (IOP and glaucoma. Genetic mapping studies utilizing YBR as a glaucoma-susceptible strain and C57BL/6J as a glaucoma-resistant strain were performed to identify genetic loci responsible for the iris disease and high IOP. A recessive locus linked to Tyrp1b on chromosome 4 contributes to iris stromal atrophy and high IOP. However, this is not the only important locus. A recessive locus on YBR chromosome 17 causes high IOP independent of the iris stromal atrophy. In specific eyes with high IOP caused by YBR chromosome 17, the drainage angle (through which ocular fluid leaves the eye is largely open. The YBR alleles of genes on chromosomes 4 and 17 underlie the development of high IOP and glaucoma but do so through independent mechanisms. Together, these two loci act in an additive manner to increase the susceptibility of YBR mice to the development of high IOP. The chromosome 17 locus is important not only because it causes IOP elevation in mice with largely open drainage angles but also because it exacerbates IOP elevation and glaucoma induced by pigment dispersion. Therefore, YBR mice are a valuable resource for studying the genetic etiology of IOP elevation and glaucoma, as well as for testing new treatments.

  15. Chromosomal Copy Number Variation in Saccharomyces pastorianus Is Evidence for Extensive Genome Dynamics in Industrial Lager Brewing Strains.

    Science.gov (United States)

    van den Broek, M; Bolat, I; Nijkamp, J F; Ramos, E; Luttik, M A H; Koopman, F; Geertman, J M; de Ridder, D; Pronk, J T; Daran, J-M

    2015-09-01

    Lager brewing strains of Saccharomyces pastorianus are natural interspecific hybrids originating from the spontaneous hybridization of Saccharomyces cerevisiae and Saccharomyces eubayanus. Over the past 500 years, S. pastorianus has been domesticated to become one of the most important industrial microorganisms. Production of lager-type beers requires a set of essential phenotypes, including the ability to ferment maltose and maltotriose at low temperature, the production of flavors and aromas, and the ability to flocculate. Understanding of the molecular basis of complex brewing-related phenotypic traits is a prerequisite for rational strain improvement. While genome sequences have been reported, the variability and dynamics of S. pastorianus genomes have not been investigated in detail. Here, using deep sequencing and chromosome copy number analysis, we showed that S. pastorianus strain CBS1483 exhibited extensive aneuploidy. This was confirmed by quantitative PCR and by flow cytometry. As a direct consequence of this aneuploidy, a massive number of sequence variants was identified, leading to at least 1,800 additional protein variants in S. pastorianus CBS1483. Analysis of eight additional S. pastorianus strains revealed that the previously defined group I strains showed comparable karyotypes, while group II strains showed large interstrain karyotypic variability. Comparison of three strains with nearly identical genome sequences revealed substantial chromosome copy number variation, which may contribute to strain-specific phenotypic traits. The observed variability of lager yeast genomes demonstrates that systematic linking of genotype to phenotype requires a three-dimensional genome analysis encompassing physical chromosomal structures, the copy number of individual chromosomes or chromosomal regions, and the allelic variation of copies of individual genes. Copyright © 2015, van den Broek et al.

  16. Simultaneous determination of seven informative Y chromosome SNPs to differentiate East Asian, European, and African populations.

    Science.gov (United States)

    Muro, Tomonori; Iida, Reiko; Fujihara, Junko; Yasuda, Toshihiro; Watanabe, Yukina; Imamura, Shinji; Nakamura, Hiroaki; Kimura-Kataoka, Kaori; Yuasa, Isao; Toga, Tomoko; Takeshita, Haruo

    2011-05-01

    Identification of the population origin of an individual is very useful for crime investigators who need to narrow down a suspect based on specimens left at a crime scene. Single nucleotide polymorphisms of the Y chromosome (Y-SNPs) are a class of markers of interest to forensic investigators because many of the markers indicate regional specificity, thus providing useful information about the geographic origin of a subject. We selected seven informative Y-SNPs (M168, M130, JST021355, M96, P126, P196, and P234) to differentiate the three major population groups (East Asian, European, and African) and used them to develop forensic application. SNP genotyping was carried out by multiplex PCR reaction and multiplex single base extension (MSBE) reaction followed by capillary electrophoresis of extension products. This method can be used to assign a haplogroup from both degraded male DNA samples and DNA samples containing a mixture of female and male DNA through PCR primers that generate small amplicons (less than about 150 bp) and are highly specific for targets on the Y chromosome. The allelic state of each marker was definitively determined from a total of 791 males from the three major population groups. As expected, samples from the three major population groups showed Y-haplogroups common in the region of provenance: Y haplogroups C, D, and O for East Asians; IJ and R1 for Europeans; and AB and E for Africans. Published by Elsevier Ireland Ltd.

  17. Chromosomal Evolution in Chiroptera

    OpenAIRE

    Sotero-Caio, Cibele G.; Baker, Robert J.; Volleth, Marianne

    2017-01-01

    Chiroptera is the second largest order among mammals, with over 1300 species in 21 extant families. The group is extremely diverse in several aspects of its natural history, including dietary strategies, ecology, behavior and morphology. Bat genomes show ample chromosome diversity (from 2n = 14 to 62). As with other mammalian orders, Chiroptera is characterized by clades with low, moderate and extreme chromosomal change. In this article, we will discuss trends of karyotypic evolution within d...

  18. Aegilops tauschii Accessions with Geographically Diverse Origin Show Differences in Chromosome Organization and Polymorphism of Molecular Markers Linked to Leaf Rust and Powdery Mildew Resistance Genes.

    Science.gov (United States)

    Majka, Maciej; Kwiatek, Michał T; Majka, Joanna; Wiśniewska, Halina

    2017-01-01

    Aegilops tauschii (2n = 2x = 14) is a diploid wild species which is reported as a donor of the D-genome of cultivated bread wheat. The main goal of this study was to examine the differences and similarities in chromosomes organization among accessions of Ae. tauschii with geographically diversed origin, which is believed as a potential source of genes, especially determining resistance to fungal diseases (i.e., leaf rust and powdery mildew) for breeding of cereals. We established and compared the fluorescence in situ hybridization patterns of 21 accessions of Ae. tauschii using various repetitive sequences mainly from the BAC library of wheat cultivar Chinese Spring. Results obtained for Ae. tauschii chromosomes revealed many similarities between analyzed accessions, however, some hybridization patterns were specific for accessions, which become from cognate regions of the World. The most noticeable differences were observed for accessions from China which were characterized by presence of distinct signals of pTa-535 in the interstitial region of chromosome 3D, less intensity of pTa-86 signals in chromosome 2D, as well as lack of additional signals of pTa-86 in chromosomes 1D, 5D, or 6D. Ae. tauschii of Chinese origin appeared homogeneous and separate from landraces that originated in western Asia. Ae. tauschii chromosomes showed similar hybridization patterns to wheat D-genome chromosomes, but some differences were also observed among both species. What is more, we identified reciprocal translocation between short arm of chromosome 1D and long arm of chromosome 7D in accession with Iranian origin. High polymorphism between analyzed accessions and extensive allelic variation were revealed using molecular markers associated with resistance genes. Majority of the markers localized in chromosomes 1D and 2D showed the diversity of banding patterns between accessions. Obtained results imply, that there is a moderate or high level of polymorphism in the genome of Ae

  19. Chromosomes in the flow to simplify genome analysis

    Czech Academy of Sciences Publication Activity Database

    Doležel, Jaroslav; Vrána, Jan; Šafář, Jan; Bartoš, Jan; Kubaláková, Marie; Šimková, Hana

    2012-01-01

    Roč. 12, č. 3 (2012), s. 397-416 ISSN 1438-793X R&D Projects: GA ČR GAP501/10/1740; GA ČR GAP501/10/1778 Institutional research plan: CEZ:AV0Z50380511 Keywords : Chromosome sorting * Chromosome-specific BAC libraries * Chromosome sequencing Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.292, year: 2012

  20. The mating-type chromosome in the filamentous ascomycete Neurospora tetrasperma represents a model for early evolution of sex chromosomes.

    Directory of Open Access Journals (Sweden)

    Audrius Menkis

    2008-03-01

    Full Text Available We combined gene divergence data, classical genetics, and phylogenetics to study the evolution of the mating-type chromosome in the filamentous ascomycete Neurospora tetrasperma. In this species, a large non-recombining region of the mating-type chromosome is associated with a unique fungal life cycle where self-fertility is enforced by maintenance of a constant state of heterokaryosis. Sequence divergence between alleles of 35 genes from the two single mating-type component strains (i.e. the homokaryotic mat A or mat a-strains, derived from one N. tetrasperma heterokaryon (mat A+mat a, was analyzed. By this approach we were able to identify the boundaries and size of the non-recombining region, and reveal insight into the history of recombination cessation. The non-recombining region covers almost 7 Mbp, over 75% of the chromosome, and we hypothesize that the evolution of the mating-type chromosome in this lineage involved two successive events. The first event was contemporaneous with the split of N. tetrasperma from a common ancestor with its outcrossing relative N. crassa and suppressed recombination over at least 6.6 Mbp, and the second was confined to a smaller region in which recombination ceased more recently. In spite of the early origin of the first "evolutionary stratum", genealogies of five genes from strains belonging to an additional N. tetrasperma lineage indicate independent initiations of suppressed recombination in different phylogenetic lineages. This study highlights the shared features between the sex chromosomes found in the animal and plant kingdoms and the fungal mating-type chromosome, despite fungi having no separate sexes. As is often found in sex chromosomes of plants and animals, recombination suppression of the mating-type chromosome of N. tetrasperma involved more than one evolutionary event, covers the majority of the mating-type chromosome and is flanked by distal regions with obligate crossovers.

  1. Alleles versus genotypes: Genetic interactions and the dynamics of selection in sexual populations

    Science.gov (United States)

    Neher, Richard

    2010-03-01

    Physical interactions between amino-acids are essential for protein structure and activity, while protein-protein interactions and regulatory interactions are central to cellular function. As a consequence of these interactions, the combined effect of two mutations can differ from the sum of the individual effects of the mutations. This phenomenon of genetic interaction is known as epistasis. However, the importance of epistasis and its effects on evolutionary dynamics are poorly understood, especially in sexual populations where recombination breaks up existing combinations of alleles to produce new ones. Here, we present a computational model of selection dynamics involving many epistatic loci in a recombining population. We demonstrate that a large number of polymorphic interacting loci can, despite frequent recombination, exhibit cooperative behavior that locks alleles into favorable genotypes leading to a population consisting of a set of competing clones. As the recombination rate exceeds a certain critical value this ``genotype selection'' phase disappears in an abrupt transition giving way to ``allele selection'' - the phase where different loci are only weakly correlated as expected in sexually reproducing populations. Clustering of interacting sets of genes on a chromosome leads to the emergence of an intermediate regime, where localized blocks of cooperating alleles lock into genetic modules. Large populations attain highest fitness at a recombination rate just below critical, suggesting that natural selection might tune recombination rates to balance the beneficial aspect of exploration of genotype space with the breaking up of synergistic allele combinations.

  2. Micromechanics of human mitotic chromosomes

    International Nuclear Information System (INIS)

    Sun, Mingxuan; Kawamura, Ryo; Marko, John F

    2011-01-01

    Eukaryote cells dramatically reorganize their long chromosomal DNAs to facilitate their physical segregation during mitosis. The internal organization of folded mitotic chromosomes remains a basic mystery of cell biology; its understanding would likely shed light on how chromosomes are separated from one another as well as into chromosome structure between cell divisions. We report biophysical experiments on single mitotic chromosomes from human cells, where we combine micromanipulation, nano-Newton-scale force measurement and biochemical treatments to study chromosome connectivity and topology. Results are in accord with previous experiments on amphibian chromosomes and support the 'chromatin network' model of mitotic chromosome structure. Prospects for studies of chromosome-organizing proteins using siRNA expression knockdowns, as well as for differential studies of chromosomes with and without mutations associated with genetic diseases, are also discussed

  3. Chromosomal inversion differences correlate with range overlap in passerine birds.

    Science.gov (United States)

    Hooper, Daniel M; Price, Trevor D

    2017-10-01

    Chromosomal inversions evolve frequently but the reasons for this remain unclear. We used cytological descriptions of 411 species of passerine birds to identify large pericentric inversion differences between species, based on the position of the centromere. Within 81 small clades comprising 284 of the species, we found 319 differences on the 9 largest autosomes combined, 56 on the Z chromosome, and 55 on the W chromosome. We also identified inversions present within 32 species. Using a new fossil-calibrated phylogeny, we examined the phylogenetic, demographic and genomic context in which these inversions have evolved. The number of inversion differences between closely related species is consistently predicted by whether the ranges of species overlap, even when time is controlled for as far as is possible. Fixation rates vary across the autosomes, but inversions are more likely to be fixed on the Z chromosome than the average autosome. Variable mutagenic input alone (estimated by chromosome size, map length, GC content or repeat density) cannot explain the differences between chromosomes in the number of inversions fixed. Together, these results support a model in which inversions increase because of their effects on recombination suppression in the face of hybridization. Other factors associated with hybridization may also contribute, including the possibility that inversions contain incompatibility alleles, making taxa less likely to collapse following secondary contact.

  4. Hitchhiking and Selective Sweeps of Plasmodium falciparum Sulfadoxine and Pyrimethamine Resistance Alleles in a Population from Central Africa▿ †

    Science.gov (United States)

    McCollum, Andrea M.; Basco, Leonardo K.; Tahar, Rachida; Udhayakumar, Venkatachalam; Escalante, Ananias A.

    2008-01-01

    Sulfadoxine-pyrimethamine (SP) resistance in Plasmodium falciparum is encoded by a number of mutations in the dihydrofolate reductase (dhfr) and dihydropteroate synthetase (dhps) genes. Here, we have characterized point mutations in dhfr and dhps and microsatellite loci around dhfr on chromosome 4 and dhps on chromosome 8 as well as neutral markers on chromosomes 2 and 3 in 332 samples from Yaoundé, Cameroon. The triple mutant dhfr haplotype that originated in Southeast Asia is the most predominant in this sample set, but we also find additional independent haplotypes at low frequency and an incipient process of genetic differentiation among alleles of Southeast Asian origin. As reported for other African populations, we find evidence of a selective sweep for resistant dhfr mutants in this Cameroonian population due to drug selection. Although we find evidence for a selective sweep in dhps mutants associated with SP resistance, the dynamics of dhps mutants appear different than those observed for dhfr mutants. Overall, our results yield support for the use of microsatellite markers to track resistant parasites; however, the detection of resistant dhfr alleles in low frequency, the evidence of divergence among dhfr alleles that share a common evolutionary origin, and the distinct dynamics of resistant dhps alleles emphasize the importance of comprehensive, population-based investigations to evaluate the effects of drug selection on parasite populations. PMID:18765692

  5. Fitness differences due to allelic variation at Esterase-4 Locus in ...

    Indian Academy of Sciences (India)

    Navya

    2017-01-04

    Jan 4, 2017 ... specific substrate (1-Naphthylacetate AR) and stain (Fast blue RR). On the basis of ... After 24 hr. each pair was transferred to fresh food vials .... derived from the natural populations harbour allelic variation that affects lifespan.

  6. Female meiotic sex chromosome inactivation in chicken.

    Directory of Open Access Journals (Sweden)

    Sam Schoenmakers

    2009-05-01

    Full Text Available During meiotic prophase in male mammals, the heterologous X and Y chromosomes remain largely unsynapsed, and meiotic sex chromosome inactivation (MSCI leads to formation of the transcriptionally silenced XY body. In birds, the heterogametic sex is female, carrying Z and W chromosomes (ZW, whereas males have the homogametic ZZ constitution. During chicken oogenesis, the heterologous ZW pair reaches a state of complete heterologous synapsis, and this might enable maintenance of transcription of Z- and W chromosomal genes during meiotic prophase. Herein, we show that the ZW pair is transiently silenced, from early pachytene to early diplotene using immunocytochemistry and gene expression analyses. We propose that ZW inactivation is most likely achieved via spreading of heterochromatin from the W on the Z chromosome. Also, persistent meiotic DNA double-strand breaks (DSBs may contribute to silencing of Z. Surprisingly, gammaH2AX, a marker of DSBs, and also the earliest histone modification that is associated with XY body formation in mammalian and marsupial spermatocytes, does not cover the ZW during the synapsed stage. However, when the ZW pair starts to desynapse, a second wave of gammaH2AX accumulates on the unsynapsed regions of Z, which also show a reappearance of the DSB repair protein RAD51. This indicates that repair of meiotic DSBs on the heterologous part of Z is postponed until late pachytene/diplotene, possibly to avoid recombination with regions on the heterologously synapsed W chromosome. Two days after entering diplotene, the Z looses gammaH2AX and shows reactivation. This is the first report of meiotic sex chromosome inactivation in a species with female heterogamety, providing evidence that this mechanism is not specific to spermatogenesis. It also indicates the presence of an evolutionary force that drives meiotic sex chromosome inactivation independent of the final achievement of synapsis.

  7. Pyramiding of transgenic Pm3 alleles in wheat results in improved powdery mildew resistance in the field.

    Science.gov (United States)

    Koller, Teresa; Brunner, Susanne; Herren, Gerhard; Hurni, Severine; Keller, Beat

    2018-04-01

    The combined effects of enhanced total transgene expression level and allele-specificity combination in transgenic allele-pyramided Pm3 wheat lines result in improved powdery mildew field resistance without negative pleiotropic effects. Allelic Pm3 resistance genes of wheat confer race-specific resistance to powdery mildew (Blumeria graminis f. sp. tritici, Bgt) and encode nucleotide-binding domain, leucine-rich repeat (NLR) receptors. Transgenic wheat lines overexpressing alleles Pm3a, b, c, d, f, and g have previously been generated by transformation of cultivar Bobwhite and tested in field trials, revealing varying degrees of powdery mildew resistance conferred by the transgenes. Here, we tested four transgenic lines each carrying two pyramided Pm3 alleles, which were generated by crossbreeding of lines transformed with single Pm3 alleles. All four allele-pyramided lines showed strongly improved powdery mildew resistance in the field compared to their parental lines. The improved resistance results from the two effects of enhanced total transgene expression levels and allele-specificity combinations. In contrast to leaf segment tests on greenhouse-grown seedlings, no allelic suppression was observed in the field. Plant development and yield scores of the pyramided lines were similar to the mean scores of the corresponding parental lines, and thus, the allele pyramiding did not cause any negative effects. On the contrary, in pyramided line, Pm3b × Pm3f normal plant development was restored compared to the delayed development and reduced seed set of parental line Pm3f. Allele-specific RT qPCR revealed additive transgene expression levels of the two Pm3 alleles in the pyramided lines. A positive correlation between total transgene expression level and powdery mildew field resistance was observed. In summary, allele pyramiding of Pm3 transgenes proved to be successful in enhancing powdery mildew field resistance.

  8. Efficient generation of long-distance conditional alleles using recombineering and a dual selection strategy in replicate plates

    Directory of Open Access Journals (Sweden)

    Liang Hong-Erh

    2009-07-01

    Full Text Available Abstract Background Conditional knockout mice are a useful tool to study the function of gene products in a tissue-specific or inducible manner. Classical approaches to generate targeting vectors for conditional alleles are often limited by the availability of suitable restriction sites. Furthermore, plasmid-based targeting vectors can only cover a few kB of DNA which precludes the generation of targeting vectors where the two loxP sites are placed far apart. These limitations have been overcome in the recent past by using homologous recombination of bacterial artificial chromosomes (BACs in Escherichia coli to produce large targeting vector containing two different loxP-flanked selection cassettes so that a single targeting event is sufficient to introduce loxP-sites a great distances into the mouse genome. However, the final targeted allele should be free of selection cassettes and screening for correct removal of selection cassettes can be a laborious task. Therefore, we developed a new strategy to rapidly identify ES cells containing the desired allele. Results Using BAC recombineering we generated a single targeting vector which contained two different selection cassettes that were flanked by loxP-loxP sites or by FRT-FRT/loxP sites so that they could be deleted sequentially by Cre- and FLPe-recombinases, respectively. Transfected ES cells were first selected in the presence of both antibiotics in vitro before correctly targeted clones were identified by Southern blot. After transfection of a Cre recombinase expression plasmid ES cell clones were selected on replicate plates to identify those clones which maintained the FRT-FRT/loxP flanked cassette and lost the loxP-loxP flanked cassette. Using this strategy facilitated the identification of ES cell clones containing the desired allele before blastocyst injection. Conclusion The strategy of ES cell cultures in replicate plates proved to be very efficient in identifying ES cells that had

  9. Type 2 diabetes risk alleles demonstrate extreme directional differentiation among human populations, compared to other diseases.

    Directory of Open Access Journals (Sweden)

    Rong Chen

    Full Text Available Many disease-susceptible SNPs exhibit significant disparity in ancestral and derived allele frequencies across worldwide populations. While previous studies have examined population differentiation of alleles at specific SNPs, global ethnic patterns of ensembles of disease risk alleles across human diseases are unexamined. To examine these patterns, we manually curated ethnic disease association data from 5,065 papers on human genetic studies representing 1,495 diseases, recording the precise risk alleles and their measured population frequencies and estimated effect sizes. We systematically compared the population frequencies of cross-ethnic risk alleles for each disease across 1,397 individuals from 11 HapMap populations, 1,064 individuals from 53 HGDP populations, and 49 individuals with whole-genome sequences from 10 populations. Type 2 diabetes (T2D demonstrated extreme directional differentiation of risk allele frequencies across human populations, compared with null distributions of European-frequency matched control genomic alleles and risk alleles for other diseases. Most T2D risk alleles share a consistent pattern of decreasing frequencies along human migration into East Asia. Furthermore, we show that these patterns contribute to disparities in predicted genetic risk across 1,397 HapMap individuals, T2D genetic risk being consistently higher for individuals in the African populations and lower in the Asian populations, irrespective of the ethnicity considered in the initial discovery of risk alleles. We observed a similar pattern in the distribution of T2D Genetic Risk Scores, which are associated with an increased risk of developing diabetes in the Diabetes Prevention Program cohort, for the same individuals. This disparity may be attributable to the promotion of energy storage and usage appropriate to environments and inconsistent energy intake. Our results indicate that the differential frequencies of T2D risk alleles may

  10. Angiotensin-converting enzyme (ACE) alleles in the Quechua, a high altitude South American native population.

    Science.gov (United States)

    Rupert, J L; Devine, D V; Monsalve, M V; Hochachka, P W

    1999-01-01

    Recently it was reported that an allelic variant of the gene encoding angiotensin-converting enzyme (ACE) was significantly over-represented in a cohort of elite British mountaineers. It was proposed that this may be evidence for a specific genetic factor influencing the human capacity for physical performance. The implication that this allele could enhance performance at high altitude prompted us to determine its frequency in Quechua speaking natives living at altitudes greater than 3000m on the Andean Altiplano in South America. We found that the frequency of the putative performance allele in the Quechuas, although significantly higher than in Caucasians, was not different from lowland Native American populations. This observation suggests that, although the higher frequency of the 'performance allele' may have facilitated the migration of the ancestral Quechua to the highlands, the ACE insertion allele has not been subsequently selected for in this high altitude population.

  11. Microangiopathic complications related to different alleles of ...

    African Journals Online (AJOL)

    Egyptian Journal of Biochemistry and Molecular Biology. Journal Home ... Microangiopathic complications related to different alleles of manganese superoxide dismutase gene in diabetes mellitus type 1. TM EL Masry ... 23(2) 2005: 155-167 ...

  12. Non-coding RNAs and epigenome: de novo DNA methylation, allelic exclusion and X-inactivation

    Directory of Open Access Journals (Sweden)

    V. A. Halytskiy

    2013-12-01

    Full Text Available Non-coding RNAs are widespread class of cell RNAs. They participate in many important processes in cells – signaling, posttranscriptional silencing, protein biosynthesis, splicing, maintenance of genome stability, telomere lengthening, X-inactivation. Nevertheless, activity of these RNAs is not restricted to posttranscriptional sphere, but cover also processes that change or maintain the epigenetic information. Non-coding RNAs can directly bind to the DNA targets and cause their repression through recruitment of DNA methyltransferases as well as chromatin modifying enzymes. Such events constitute molecular mechanism of the RNA-dependent DNA methylation. It is possible, that the RNA-DNA interaction is universal mechanism triggering DNA methylation de novo. Allelic exclusion can be also based on described mechanism. This phenomenon takes place, when non-coding RNA, which precursor is transcribed from one allele, triggers DNA methylation in all other alleles present in the cell. Note, that miRNA-mediated transcriptional silencing resembles allelic exclusion, because both miRNA gene and genes, which can be targeted by this miRNA, contain elements with the same sequences. It can be assumed that RNA-dependent DNA methylation and allelic exclusion originated with the purpose of counteracting the activity of mobile genetic elements. Probably, thinning and deregulation of the cellular non-coding RNA pattern allows reactivation of silent mobile genetic elements resulting in genome instability that leads to ageing and carcinogenesis. In the course of X-inactivation, DNA methylation and subsequent hete­rochromatinization of X chromosome can be triggered by direct hybridization of 5′-end of large non-coding RNA Xist with DNA targets in remote regions of the X chromosome.

  13. An allele-specific polymerase chain reaction assay for the ...

    Indian Academy of Sciences (India)

    Unknown

    designated as species A, B (Green and Miles 1980), C. (Subbarao et al 1983), ... onstrated in laboratory feeding experiments on three members of An. .... in Rameshwaram Island and Sri Lanka only) are not pre- sent. For example, in most of ...

  14. An allele-specific polymerase chain reaction assay for the ...

    Indian Academy of Sciences (India)

    Unknown

    designated as species A, B (Green and Miles 1980), C. (Subbarao et al 1983), ... 3 | September 2004. O P Singh et al. 276 able to distinguish species A from species B/C when sin- gle mosquito-extract was diluted to 1/200. However such hybridization assay .... in Rameshwaram Island and Sri Lanka only) are not pre- sent.

  15. Molecular mapping of chromosomes 17 and X

    Energy Technology Data Exchange (ETDEWEB)

    Barker, D.F.

    1991-01-15

    Progress toward the construction of high density genetic maps of chromosomes 17 and X has been made by isolating and characterizing a relatively large set of polymorphic probes for each chromosome and using these probes to construct genetic maps. We have mapped the same polymorphic probes against a series of chromosome breakpoints on X and 17. The probes could be assigned to over 30 physical intervals on the X chromosome and 7 intervals on 17. In many cases, this process resulted in improved characterization of the relative locations of the breakpoints with respect to each other and the definition of new physical intervals. The strategy for isolation of the polymorphic clones utilized chromosome specific libraries of 1--15 kb segments from each of the two chromosomes. From these libraries, clones were screened for those detecting restriction fragment length polymorphisms. The markers were further characterized, the chromosomal assignments confirmed and in most cases segments of the original probes were subcloned into plasmids to produce probes with improved signal to noise ratios for use in the genetic marker studies. The linkage studies utilize the CEPH reference families and other well-characterized families in our collection which have been used for genetic disease linkage work. Preliminary maps and maps of portions of specific regions of 17 and X are provided. We have nearly completed a map of the 1 megabase Mycoplasma arthritidis genome by applying these techniques to a lambda phage library of its genome. We have found bit mapping to be an efficient means to organize a contiguous set of overlapping clones from a larger genome.

  16. Radiation hybrid mapping of human chromosome 18

    International Nuclear Information System (INIS)

    Francke, U.; Moon, A.J.; Chang, E.; Foellmer, B.; Strauss, B.; Haschke, A.; Chihlin Hsieh; Geigl, E.M.; Welch, S.

    1990-01-01

    The authors have generated a Chinese hamster V79/380-6 HPRT minus x human leukocyte hybrid cell line (18/V79) with chromosome 18 as the only human chromosome that is retained at high frequency without specific selection. Hybrid cells were selected in HAT medium, and 164 individual colonies were isolated. Of 110 colonies screened for human DNA by PCR amplification using a primer specific for human Alu repeats 67 (61%) were positive. These were expanded in culture for large-scale DNA preparations. Retesting expanded clones by PCR with Alu and LINE primers has revealed unique patterns of amplification products. In situ hybridization of biotin labelled total human DNA to metaphase spreads from various hybrids revealed the presence of one or more human DNA fragments integrated in hamster chromosomes. The authors have generated a resource that should allow the construction of a radiation map, to be compared with the YAC contig map also under construction in their laboratory

  17. Marker chromosome 21 identified by microdissection and FISH

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Y.; Palmer, C.G. [Indiana Univ. School of Medicine, Indianapolis, IN (United States); Rubinstein, J. [Univ. Affiliated Cincinnati Center for Developmental Disorders, OH (United States)] [and others

    1995-03-27

    A child without Down`s syndrome but with developmental delay, short stature, and autistic behavior was found to be mosaic 46,XX/47,XX,+mar(21) de novo. The marker was a small ring or dot-like chromosome. Microdissection of the marker was performed. The dissected fragments were biotinylated with sequence-independent PCR as a probe pool for fluorescence in situ hybridization (FISH). FISH results suggested an acrocentric origin of the marker. Subsequent FISH with {alpha}-satellite DNA probes for acrocentric chromosomes and chromosome-specific 21 and 22 painting probes confirmed its origin from chromosome 21. 14 refs., 3 figs.

  18. Distribution of coat-color-associated alleles in the domestic horse population and Przewalski's horse.

    Science.gov (United States)

    Reissmann, Monika; Musa, Lutfi; Zakizadeh, Sonia; Ludwig, Arne

    2016-11-01

    Considering the hidden mode of inheritance of some coat-color-associated alleles, we investigated the presence/absence of coat-color-associated alleles in 1093 domestic horses of 55 breeds and 20 specimens of Przewalski's horse. For coat-color genotyping, allele specific PCR, pyrosequencing and Li-Cor analyses were conducted on 12 coat-color-associated alleles of five genes. Our data provide deep insight into the distribution of coat-color-associated alleles within breeds. We found that the alleles for the basic colorations (bay, black, and chestnut) are widely distributed and occur in nearly all breeds. Alleles leading to dilutions or patterns are rare in domestic breeds and were not found in Przewalski's horse. Higher frequencies of these alleles are only found in breeds that are selected for their expressed phenotypes (e.g., Kinsky horse, Lewitzer, Tinker). Nevertheless, our study produced strong evidence that molecular testing of the coat color is necessary for well-defined phenotyping to avoid unexpected colorations of offspring that can result in legal action.

  19. Analysis of root-knot nematode and fusarium wilt disease resistance in cotton (Gossypium spp.) using chromosome substitution lines from two alien species

    Science.gov (United States)

    To Identify a new germplasm resource, and to validate chromosomal regions and favorable alleles associated with nematode and fungal disease resistance traits, a series of interspecific cotton (Gossypium spp.) chromosome substitution (CS) lines were used in this study. The CS lines were developed in ...

  20. Y chromosome STR typing in crime casework.

    Science.gov (United States)

    Roewer, Lutz

    2009-01-01

    Since the beginning of the nineties the field of forensic Y chromosome analysis has been successfully developed to become commonplace in laboratories working in crime casework all over the world. The ability to identify male-specific DNA renders highly variable Y-chromosomal polymorphisms, the STR sequences, an invaluable addition to the standard panel of autosomal loci used in forensic genetics. The male-specificity makes the Y chromosome especially useful in cases of male/female cell admixture, namely in sexual assault cases. On the other hand, the haploidy and patrilineal inheritance complicates the interpretation of a Y-STR match, because male relatives share for several generations an identical Y-STR profile. Since paternal relatives tend to live in the geographic and cultural territory of their ancestors, the Y chromosome analysis has a potential to make inferences on the population of origin of a given DNA profile. This review addresses the fields of application of Y chromosome haplotyping, the interpretation of results, databasing efforts and population genetics aspects.

  1. Abnormal segregation of alleles in CEPH pedigree DNAs arising from allele loss in lymphoblastoid DNA.

    Science.gov (United States)

    Royle, N J; Armour, J A; Crosier, M; Jeffreys, A J

    1993-01-01

    Somatic events that result in the reduction to hemi- or homozygosity at all loci affected by the event have been identified in lymphoblastoid DNA from mothers of two CEPH families. Using suitably informative probes, the allele deficiencies were detected by the abnormal transmission of alleles from grandparents to grandchildren, with the apparent absence of the alleles from the parent. Undetected somatic deficiencies in family DNAs could result in misscoring of recombination events and consequently introduce errors into linkage analysis.

  2. The study of human Y chromosome variation through ancient DNA.

    Science.gov (United States)

    Kivisild, Toomas

    2017-05-01

    High throughput sequencing methods have completely transformed the study of human Y chromosome variation by offering a genome-scale view on genetic variation retrieved from ancient human remains in context of a growing number of high coverage whole Y chromosome sequence data from living populations from across the world. The ancient Y chromosome sequences are providing us the first exciting glimpses into the past variation of male-specific compartment of the genome and the opportunity to evaluate models based on previously made inferences from patterns of genetic variation in living populations. Analyses of the ancient Y chromosome sequences are challenging not only because of issues generally related to ancient DNA work, such as DNA damage-induced mutations and low content of endogenous DNA in most human remains, but also because of specific properties of the Y chromosome, such as its highly repetitive nature and high homology with the X chromosome. Shotgun sequencing of uniquely mapping regions of the Y chromosomes to sufficiently high coverage is still challenging and costly in poorly preserved samples. To increase the coverage of specific target SNPs capture-based methods have been developed and used in recent years to generate Y chromosome sequence data from hundreds of prehistoric skeletal remains. Besides the prospects of testing directly as how much genetic change in a given time period has accompanied changes in material culture the sequencing of ancient Y chromosomes allows us also to better understand the rate at which mutations accumulate and get fixed over time. This review considers genome-scale evidence on ancient Y chromosome diversity that has recently started to accumulate in geographic areas favourable to DNA preservation. More specifically the review focuses on examples of regional continuity and change of the Y chromosome haplogroups in North Eurasia and in the New World.

  3. Supernumerary ring chromosome 20 characterized by fluorescence in situ hybridization

    NARCIS (Netherlands)

    Van Langen, Irene M.; Otter, Mariëlle A.; Aronson, Daniël C.; Overweg-Plandsoen, W.C.G.; Hennekam, Raoul C.M.; Leschot, Nico J.; Hoovers, Jan M.N.

    1996-01-01

    We report on a boy with mild dysmorphic features and developmental delay, in whom karyotyping showed an additional minute ring chromosome in 60% of metaphases. Fluorescence in situ hybridization (FISH) with a centromere specific probe demonstrated that the ring chromosome contained the centromeric

  4. Genome organization influences partner selection for chromosomal rearrangements

    NARCIS (Netherlands)

    Wijchers, P.J.; de Laat, W.

    2010-01-01

    Chromosomal rearrangements occur as a consequence of the erroneous repair of DNA double-stranded breaks, and often underlie disease. The recurrent detection of specific tumorigenic rearrangements suggests that there is a mechanism behind chromosomal partner selection involving the shape of the

  5. Forensic use of Y-chromosome DNA: a general overview

    NARCIS (Netherlands)

    M.H. Kayser (Manfred)

    2017-01-01

    textabstractThe male-specific part of the human Y chromosome is widely used in forensic DNA analysis, particularly in cases where standard autosomal DNA profiling is not informative. A Y-chromosomal gene fragment is applied for inferring the biological sex of a crime scene trace donor. Haplotypes

  6. Loss-of-heterozygosity on chromosome 19q in early-stage serous ovarian cancer is associated with recurrent disease

    International Nuclear Information System (INIS)

    Skirnisdottir, Ingiridur; Mayrhofer, Markus; Rydåker, Maria; Åkerud, Helena; Isaksson, Anders

    2012-01-01

    Ovarian cancer is a heterogeneous disease and prognosis for apparently similar cases of ovarian cancer varies. Recurrence of the disease in early stage (FIGO-stages I-II) serous ovarian cancer results in survival that is comparable to those with recurrent advanced-stage disease. The aim of this study was to investigate if there are specific genomic aberrations that may explain recurrence and clinical outcome. Fifty-one women with early stage serous ovarian cancer were included in the study. DNA was extracted from formalin fixed samples containing tumor cells from ovarian tumors. Tumor samples from thirty-seven patients were analysed for allele-specific copy numbers using OncoScan single nucleotide polymorphism arrays from Affymetrix and the bioinformatic tool Tumor Aberration Prediction Suite. Genomic gains, losses, and loss-of-heterozygosity that associated with recurrent disease were identified. The most significant differences (p < 0.01) in Loss-of-heterozygosity (LOH) were identified in two relatively small regions of chromosome 19; 8.0-8,8 Mbp (19 genes) and 51.5-53.0 Mbp (37 genes). Thus, 56 genes on chromosome 19 were potential candidate genes associated with clinical outcome. LOH at 19q (51-56 Mbp) was associated with shorter disease-free survival and was an independent prognostic factor for survival in a multivariate Cox regression analysis. In particular LOH on chromosome 19q (51-56 Mbp) was significantly (p < 0.01) associated with loss of TP53 function. The results of our study indicate that presence of two aberrations in TP53 on 17p and LOH on 19q in early stage serous ovarian cancer is associated with recurrent disease. Further studies related to the findings of chromosomes 17 and 19 are needed to elucidate the molecular mechanism behind the recurring genomic aberrations and the poor clinical outcome

  7. X chromosome control of meiotic chromosome synapsis in mouse inter-subspecific hybrids.

    Directory of Open Access Journals (Sweden)

    Tanmoy Bhattacharyya

    2014-02-01

    Full Text Available Hybrid sterility (HS belongs to reproductive isolation barriers that safeguard the integrity of species in statu nascendi. Although hybrid sterility occurs almost universally among animal and plant species, most of our current knowledge comes from the classical genetic studies on Drosophila interspecific crosses or introgressions. With the house mouse subspecies Mus m. musculus and Mus m. domesticus as a model, new research tools have become available for studies of the molecular mechanisms and genetic networks underlying HS. Here we used QTL analysis and intersubspecific chromosome substitution strains to identify a 4.7 Mb critical region on Chromosome X (Chr X harboring the Hstx2 HS locus, which causes asymmetrical spermatogenic arrest in reciprocal intersubspecific F1 hybrids. Subsequently, we mapped autosomal loci on Chrs 3, 9 and 13 that can abolish this asymmetry. Combination of immunofluorescent visualization of the proteins of synaptonemal complexes with whole-chromosome DNA FISH on pachytene spreads revealed that heterosubspecific, unlike consubspecific, homologous chromosomes are predisposed to asynapsis in F1 hybrid male and female meiosis. The asynapsis is under the trans- control of Hstx2 and Hst1/Prdm9 hybrid sterility genes in pachynemas of male but not female hybrids. The finding concurred with the fertility of intersubpecific F1 hybrid females homozygous for the Hstx2(Mmm allele and resolved the apparent conflict with the dominance theory of Haldane's rule. We propose that meiotic asynapsis in intersubspecific hybrids is a consequence of cis-acting mismatch between homologous chromosomes modulated by the trans-acting Hstx2 and Prdm9 hybrid male sterility genes.

  8. X chromosome control of meiotic chromosome synapsis in mouse inter-subspecific hybrids.

    Science.gov (United States)

    Bhattacharyya, Tanmoy; Reifova, Radka; Gregorova, Sona; Simecek, Petr; Gergelits, Vaclav; Mistrik, Martin; Martincova, Iva; Pialek, Jaroslav; Forejt, Jiri

    2014-02-01

    Hybrid sterility (HS) belongs to reproductive isolation barriers that safeguard the integrity of species in statu nascendi. Although hybrid sterility occurs almost universally among animal and plant species, most of our current knowledge comes from the classical genetic studies on Drosophila interspecific crosses or introgressions. With the house mouse subspecies Mus m. musculus and Mus m. domesticus as a model, new research tools have become available for studies of the molecular mechanisms and genetic networks underlying HS. Here we used QTL analysis and intersubspecific chromosome substitution strains to identify a 4.7 Mb critical region on Chromosome X (Chr X) harboring the Hstx2 HS locus, which causes asymmetrical spermatogenic arrest in reciprocal intersubspecific F1 hybrids. Subsequently, we mapped autosomal loci on Chrs 3, 9 and 13 that can abolish this asymmetry. Combination of immunofluorescent visualization of the proteins of synaptonemal complexes with whole-chromosome DNA FISH on pachytene spreads revealed that heterosubspecific, unlike consubspecific, homologous chromosomes are predisposed to asynapsis in F1 hybrid male and female meiosis. The asynapsis is under the trans- control of Hstx2 and Hst1/Prdm9 hybrid sterility genes in pachynemas of male but not female hybrids. The finding concurred with the fertility of intersubpecific F1 hybrid females homozygous for the Hstx2(Mmm) allele and resolved the apparent conflict with the dominance theory of Haldane's rule. We propose that meiotic asynapsis in intersubspecific hybrids is a consequence of cis-acting mismatch between homologous chromosomes modulated by the trans-acting Hstx2 and Prdm9 hybrid male sterility genes.

  9. X Chromosome Control of Meiotic Chromosome Synapsis in Mouse Inter-Subspecific Hybrids

    Science.gov (United States)

    Bhattacharyya, Tanmoy; Reifova, Radka; Gregorova, Sona; Simecek, Petr; Gergelits, Vaclav; Mistrik, Martin; Martincova, Iva; Pialek, Jaroslav; Forejt, Jiri

    2014-01-01

    Hybrid sterility (HS) belongs to reproductive isolation barriers that safeguard the integrity of species in statu nascendi. Although hybrid sterility occurs almost universally among animal and plant species, most of our current knowledge comes from the classical genetic studies on Drosophila interspecific crosses or introgressions. With the house mouse subspecies Mus m. musculus and Mus m. domesticus as a model, new research tools have become available for studies of the molecular mechanisms and genetic networks underlying HS. Here we used QTL analysis and intersubspecific chromosome substitution strains to identify a 4.7 Mb critical region on Chromosome X (Chr X) harboring the Hstx2 HS locus, which causes asymmetrical spermatogenic arrest in reciprocal intersubspecific F1 hybrids. Subsequently, we mapped autosomal loci on Chrs 3, 9 and 13 that can abolish this asymmetry. Combination of immunofluorescent visualization of the proteins of synaptonemal complexes with whole-chromosome DNA FISH on pachytene spreads revealed that heterosubspecific, unlike consubspecific, homologous chromosomes are predisposed to asynapsis in F1 hybrid male and female meiosis. The asynapsis is under the trans- control of Hstx2 and Hst1/Prdm9 hybrid sterility genes in pachynemas of male but not female hybrids. The finding concurred with the fertility of intersubpecific F1 hybrid females homozygous for the Hstx2Mmm allele and resolved the apparent conflict with the dominance theory of Haldane's rule. We propose that meiotic asynapsis in intersubspecific hybrids is a consequence of cis-acting mismatch between homologous chromosomes modulated by the trans-acting Hstx2 and Prdm9 hybrid male sterility genes. PMID:24516397

  10. Linkage group-chromosome correlations in Sordaria macrospora: Chromosome identification by three dimensional reconstruction of their synaptonemal complex.

    Science.gov (United States)

    Zickler, D; Leblon, G; Haedens, V; Collard, A; Thuriaux, P

    1984-01-01

    Reconstruction of serially sectioned zygotene and pachytene nuclei has allowed, by measuring the lengths of synaptonemal complexes, an assignment of the 7 linkage (LG) groups to the 7 chromosomes in the fungus Sordaria macrospora. The 7 LG have been established using 19 mutants showing low second division segregation frequencies. Eight chromosomal rearrangements mapped on the 7 LG were used to identify the chromosomes involved. The following one to one assignment of the 7 LG to specific chromosomes was obtained: LG a: chromosome (chr) 1, LG b: chr5, LG c: chr6, LG d: chr7, LG e: chr4, LG f: chr3 and LG g: chr2 (the chromosome carrying the nucleolus organizer region).

  11. Telomere dysfunction and chromosome structure modulate the contribution of individual chromosomes in abnormal nuclear morphologies

    Energy Technology Data Exchange (ETDEWEB)

    Pampalona, J.; Soler, D.; Genesca, A. [Department of Cell Biology, Physiology and Immunology, Universitat Autonoma de Barcelona, Bellaterra E-08193 (Spain); Tusell, L., E-mail: laura.tusell@uab.es [Department of Cell Biology, Physiology and Immunology, Universitat Autonoma de Barcelona, Bellaterra E-08193 (Spain)

    2010-01-05

    The cytokinesis-block micronucleus assay has emerged as a biomarker of chromosome damage relevant to cancer. Although it was initially developed to measure micronuclei, it is also useful for measuring nucleoplasmic bridges and nuclear buds. Abnormal nuclear morphologies are frequently observed in malignant tissues and short-term tumour cell cultures. Changes in chromosome structure and number resulting from chromosome instability are important factors in oncogenesis. Telomeres have become key players in the initiation of chromosome instability related to carcinogenesis by means of breakage-fusion-bridge cycles. To better understand the connection between telomere dysfunction and the appearance of abnormal nuclear morphologies, we have characterised the presence of micronuclei, nucleoplasmic bridges and nuclear buds in human mammary primary epithelial cells. These cells can proliferate beyond the Hayflick limit by spontaneously losing expression of the p16{sup INK4a} protein. Progressive telomere shortening leads to the loss of the capping function, and the appearance of end-to-end chromosome fusions that can enter into breakage-fusion-bridge cycles generating massive chromosomal instability. In human mammary epithelial cells, different types of abnormal nuclear morphologies were observed, however only nucleoplasmatic bridges and buds increased significantly with population doublings. Fluorescent in situ hybridisation using centromeric and painting specific probes for chromosomes with eroded telomeres has revealed that these chromosomes are preferentially included in the different types of abnormal nuclear morphologies observed, thus reflecting their common origin. Accordingly, real-time imaging of cell divisions enabled us to determine that anaphase bridge resolution was mainly through chromatin breakage and the formation of symmetric buds in daughter nuclei. Few micronuclei emerged in this cell system thus validating the scoring of nucleoplasmic bridges and

  12. Telomere dysfunction and chromosome structure modulate the contribution of individual chromosomes in abnormal nuclear morphologies

    International Nuclear Information System (INIS)

    Pampalona, J.; Soler, D.; Genesca, A.; Tusell, L.

    2010-01-01

    The cytokinesis-block micronucleus assay has emerged as a biomarker of chromosome damage relevant to cancer. Although it was initially developed to measure micronuclei, it is also useful for measuring nucleoplasmic bridges and nuclear buds. Abnormal nuclear morphologies are frequently observed in malignant tissues and short-term tumour cell cultures. Changes in chromosome structure and number resulting from chromosome instability are important factors in oncogenesis. Telomeres have become key players in the initiation of chromosome instability related to carcinogenesis by means of breakage-fusion-bridge cycles. To better understand the connection between telomere dysfunction and the appearance of abnormal nuclear morphologies, we have characterised the presence of micronuclei, nucleoplasmic bridges and nuclear buds in human mammary primary epithelial cells. These cells can proliferate beyond the Hayflick limit by spontaneously losing expression of the p16 INK4a protein. Progressive telomere shortening leads to the loss of the capping function, and the appearance of end-to-end chromosome fusions that can enter into breakage-fusion-bridge cycles generating massive chromosomal instability. In human mammary epithelial cells, different types of abnormal nuclear morphologies were observed, however only nucleoplasmatic bridges and buds increased significantly with population doublings. Fluorescent in situ hybridisation using centromeric and painting specific probes for chromosomes with eroded telomeres has revealed that these chromosomes are preferentially included in the different types of abnormal nuclear morphologies observed, thus reflecting their common origin. Accordingly, real-time imaging of cell divisions enabled us to determine that anaphase bridge resolution was mainly through chromatin breakage and the formation of symmetric buds in daughter nuclei. Few micronuclei emerged in this cell system thus validating the scoring of nucleoplasmic bridges and nuclear

  13. Telomere dysfunction and chromosome structure modulate the contribution of individual chromosomes in abnormal nuclear morphologies.

    Science.gov (United States)

    Pampalona, J; Soler, D; Genescà, A; Tusell, L

    2010-01-05

    The cytokinesis-block micronucleus assay has emerged as a biomarker of chromosome damage relevant to cancer. Although it was initially developed to measure micronuclei, it is also useful for measuring nucleoplasmic bridges and nuclear buds. Abnormal nuclear morphologies are frequently observed in malignant tissues and short-term tumour cell cultures. Changes in chromosome structure and number resulting from chromosome instability are important factors in oncogenesis. Telomeres have become key players in the initiation of chromosome instability related to carcinogenesis by means of breakage-fusion-bridge cycles. To better understand the connection between telomere dysfunction and the appearance of abnormal nuclear morphologies, we have characterised the presence of micronuclei, nucleoplasmic bridges and nuclear buds in human mammary primary epithelial cells. These cells can proliferate beyond the Hayflick limit by spontaneously losing expression of the p16(INK4a) protein. Progressive telomere shortening leads to the loss of the capping function, and the appearance of end-to-end chromosome fusions that can enter into breakage-fusion-bridge cycles generating massive chromosomal instability. In human mammary epithelial cells, different types of abnormal nuclear morphologies were observed, however only nucleoplasmatic bridges and buds increased significantly with population doublings. Fluorescent in situ hybridisation using centromeric and painting specific probes for chromosomes with eroded telomeres has revealed that these chromosomes are preferentially included in the different types of abnormal nuclear morphologies observed, thus reflecting their common origin. Accordingly, real-time imaging of cell divisions enabled us to determine that anaphase bridge resolution was mainly through chromatin breakage and the formation of symmetric buds in daughter nuclei. Few micronuclei emerged in this cell system thus validating the scoring of nucleoplasmic bridges and nuclear

  14. Selfish supernumerary chromosome reveals its origin as a mosaic of host genome and organellar sequences.

    Science.gov (United States)

    Martis, Mihaela Maria; Klemme, Sonja; Banaei-Moghaddam, Ali Mohammad; Blattner, Frank R; Macas, Jiří; Schmutzer, Thomas; Scholz, Uwe; Gundlach, Heidrun; Wicker, Thomas; Šimková, Hana; Novák, Petr; Neumann, Pavel; Kubaláková, Marie; Bauer, Eva; Haseneyer, Grit; Fuchs, Jörg; Doležel, Jaroslav; Stein, Nils; Mayer, Klaus F X; Houben, Andreas

    2012-08-14

    Supernumerary B chromosomes are optional additions to the basic set of A chromosomes, and occur in all eukaryotic groups. They differ from the basic complement in morphology, pairing behavior, and inheritance and are not required for normal growth and development. The current view is that B chromosomes are parasitic elements comparable to selfish DNA, like transposons. In contrast to transposons, they are autonomously inherited independent of the host genome and have their own mechanisms of mitotic or meiotic drive. Although B chromosomes were first described a century ago, little is known about their origin and molecular makeup. The widely accepted view is that they are derived from fragments of A chromosomes and/or generated in response to interspecific hybridization. Through next-generation sequencing of sorted A and B chromosomes, we show that B chromosomes of rye are rich in gene-derived sequences, allowing us to trace their origin to fragments of A chromosomes, with the largest parts corresponding to rye chromosomes 3R and 7R. Compared with A chromosomes, B chromosomes were also found to accumulate large amounts of specific repeats and insertions of organellar DNA. The origin of rye B chromosomes occurred an estimated ∼1.1-1.3 Mya, overlapping in time with the onset of the genus Secale (1.7 Mya). We propose a comprehensive model of B chromosome evolution, including its origin by recombination of several A chromosomes followed by capturing of additional A-derived and organellar sequences and amplification of B-specific repeats.

  15. Early embryonic failure: Expression and imprinted status of candidate genes on human chromosome 21

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, L.S.; Bennett, P.R.; Moore, G.E. [Queen Charlotte`s and Chelsea Hospital, London (United Kingdom)

    1994-09-01

    Two cases of maternal uniparental (hetero)disomy for human chromosome 21 (mUPD21) have been identified in a systematic search for UPD in 23 cases of early embryonic failure (EEF). Bi-parental origin of the other chromosome pairs was confirmed using specific VNTR probes or dinucleotide repeat analysis. Both maternally and paternally derived isochromosomes 21q have previously been identified in two individuals with normal phenotypes. Full UPD21 has a different mechanism of origin than uniparental isochromosome 21q and its effect on imprinted genes and phenotypic outcome will therefore not necessarily be the same. EEF associated with mUPD21 suggests that developmentally important genes on HSA 21 may be imprinted such that they are only expressed from either the maternally or paternally derived alleles. We have searched for monoallelic expression of candidate genes on HSA 21 in human pregnancy (CBS, IFNAR, COL6A1) using intragenic DNA polymorphisms. These genes were chosen either because their murine homologues lie in imprinted regions or because they are potentially important in embryogenesis. Once imprinted candidate genes have been identified, their methylation status and expression in normal, early embryonic failure and uniparental disomy 21 pregnancies will be studied. At the same time, a larger number of cases of EEF are being examined to further investigate the incidence of UPD21 in this group.

  16. Evaluating the relationship between spermatogenic silencing of the X chromosome and evolution of the Y chromosome in chimpanzee and human

    NARCIS (Netherlands)

    E. Mulugeta (Eskeatnaf); W.M. Baarends (Willy); J.H. Gribnau (Joost); J.A. Grootegoed (Anton)

    2010-01-01

    textabstractChimpanzees and humans are genetically very similar, with the striking exception of their Y chromosomes, which have diverged tremendously. The male-specific region (MSY), representing the greater part of the Y chromosome, is inherited from father to son in a clonal fashion, with natural

  17. Twelve single nucleotide polymorphisms on chromosome 19q13.2-13.3

    DEFF Research Database (Denmark)

    Yin, Jiaoyang; Vogel, Ulla; Gerdes, Lars Ulrik

    2003-01-01

    The genetic susceptibility to basal cell carcinoma (BCC) among Danish psoriatic patients was investigated in association studies with 12 single nucleotide polymorphisms on chromosome 19q13.2-3. The results show a significant association between BCC and the A-allele of a polymorphism in ERCCI exon4...

  18. Nested Inversion Polymorphisms Predispose Chromosome 22q11.2 to Meiotic Rearrangements

    NARCIS (Netherlands)

    Demaerel, Wolfram; Hestand, Matthew S.; Vergaelen, Elfi; Swillen, Ann; López-Sánchez, Marcos; Pérez-Jurado, Luis A.; McDonald-Mcginn, Donna M.; Zackai, Elaine; Emanuel, Beverly S.; Morrow, Bernice E.; Breckpot, Jeroen; Devriendt, Koenraad; Vermeesch, Joris R.; Antshel, Kevin M.; Arango, Celso; Armando, Marco; Bassett, Anne S.; Bearden, Carrie E.; Boot, Erik; Bravo-Sanchez, Marta; Breetvelt, Elemi; Busa, Tiffany; Butcher, Nancy J.; Campbell, Linda E.; Carmel, Miri; Chow, Eva W C; Crowley, T. Blaine; Cubells, Joseph; Cutler, David; Demaerel, Wolfram; Digilio, Maria Cristina; Duijff, Sasja; Eliez, Stephan; Emanuel, Beverly S.; Epstein, Michael P.; Evers, Rens; Fernandez Garcia-Moya, Luis; Fiksinski, Ania; Fraguas, David; Fremont, Wanda; Fritsch, Rosemarie; Garcia-Minaur, Sixto; Golden, Aaron; Gothelf, Doron; Guo, Tingwei; Gur, Ruben C.; Gur, Raquel E.; Heine-Suner, Damian; Hestand, Matthew; Hooper, Stephen R.; Kates, Wendy R.; Kushan, Leila; Laorden-Nieto, Alejandra; Maeder, Johanna; Marino, Bruno; Marshall, Christian R.; McCabe, Kathryn; McDonald-Mcginn, Donna M.; Michaelovosky, Elena; Morrow, Bernice E.; Moss, Edward; Mulle, Jennifer; Murphy, Declan; Murphy, Kieran C.; Murphy, Clodagh M.; Niarchou, Maria; Ornstein, Claudia; Owen, Michael J; Philip, Nicole; Repetto, Gabriela M.; Schneider, Maude; Shashi, Vandana; Simon, Tony J.; Swillen, Ann; Tassone, Flora; Unolt, Marta; Van Amelsvoort, Therese; van den Bree, Marianne B M; Van Duin, Esther; Vergaelen, Elfi; Vermeesch, Joris R.; Vicari, Stefano; Vingerhoets, Claudia; Vorstman, Jacob; Warren, Steve; Weinberger, Ronnie; Weisman, Omri; Weizman, Abraham; Zackai, Elaine; Zhang, Zhengdong; Zwick, Michael

    2017-01-01

    Inversion polymorphisms between low-copy repeats (LCRs) might predispose chromosomes to meiotic non-allelic homologous recombination (NAHR) events and thus lead to genomic disorders. However, for the 22q11.2 deletion syndrome (22q11.2DS), the most common genomic disorder, no such inversions have

  19. Genetic sub-structure in western Mediterranean populations revealed by 12 Y-chromosome STR loci

    DEFF Research Database (Denmark)

    Rodríguez, V; Tomas Mas, Carmen; Sánchez, J J

    2008-01-01

    Haplotype and allele frequencies of 12 Y-chromosome short tandem repeat (Y-STR) loci (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385 a/b, DYS437, DYS438 and DYS439) included in the Powerplex(R) Y System were determined in seven western Mediterranean populations from Valencia, Ma...

  20. Preferential Allele Expression Analysis Identifies Shared Germline and Somatic Driver Genes in Advanced Ovarian Cancer

    Science.gov (United States)

    Halabi, Najeeb M.; Martinez, Alejandra; Al-Farsi, Halema; Mery, Eliane; Puydenus, Laurence; Pujol, Pascal; Khalak, Hanif G.; McLurcan, Cameron; Ferron, Gwenael; Querleu, Denis; Al-Azwani, Iman; Al-Dous, Eman; Mohamoud, Yasmin A.; Malek, Joel A.; Rafii, Arash

    2016-01-01

    Identifying genes where a variant allele is preferentially expressed in tumors could lead to a better understanding of cancer biology and optimization of targeted therapy. However, tumor sample heterogeneity complicates standard approaches for detecting preferential allele expression. We therefore developed a novel approach combining genome and transcriptome sequencing data from the same sample that corrects for sample heterogeneity and identifies significant preferentially expressed alleles. We applied this analysis to epithelial ovarian cancer samples consisting of matched primary ovary and peritoneum and lymph node metastasis. We find that preferentially expressed variant alleles include germline and somatic variants, are shared at a relatively high frequency between patients, and are in gene networks known to be involved in cancer processes. Analysis at a patient level identifies patient-specific preferentially expressed alleles in genes that are targets for known drugs. Analysis at a site level identifies patterns of site specific preferential allele expression with similar pathways being impacted in the primary and metastasis sites. We conclude that genes with preferentially expressed variant alleles can act as cancer drivers and that targeting those genes could lead to new therapeutic strategies. PMID:26735499

  1. Specific TP53 Mutants Overrepresented in Ovarian Cancer Impact CNV, TP53 Activity, Responses to Nutlin-3a, and Cell Survival

    Directory of Open Access Journals (Sweden)

    Lisa K. Mullany

    2015-10-01

    Full Text Available Evolutionary Action analyses of The Cancer Gene Atlas data sets show that many specific p53 missense and gain-of-function mutations are selectively overrepresented and functional in high-grade serous ovarian cancer (HGSC. As homozygous alleles, p53 mutants are differentially associated with specific loss of heterozygosity (R273; chromosome 17; copy number variation (R175H; chromosome 9; and up-stream, cancer-related regulatory pathways. The expression of immune-related cytokines was selectively related to p53 status, showing for the first time that specific p53 mutants impact, and are related to, the immune subtype of ovarian cancer. Although the majority (31% of HGSCs exhibit loss of heterozygosity, a significant number (24% maintain a wild-type (WT allele and represent another HGSC subtype that is not well defined. Using human and mouse cell lines, we show that specific p53 mutants differentially alter endogenous WT p53 activity; target gene expression; and responses to nutlin-3a, a small molecular that activates WT p53 leading to apoptosis, providing “proof of principle” that ovarian cancer cells expressing WT and mutant alleles represent a distinct ovarian cancer subtype. We also show that siRNA knock down of endogenous p53 in cells expressing homozygous mutant alleles causes apoptosis, whereas cells expressing WT p53 (or are heterozygous for WT and mutant p53 alleles are highly resistant. Therefore, despite different gene regulatory pathways associated with specific p53 mutants, silencing mutant p53 might be a suitable, powerful, global strategy for blocking ovarian cancer growth in those tumors that rely on mutant p53 functions for survival. Knowing p53 mutational status in HGSC should permit new strategies tailored to control this disease.

  2. Introgressive hybridization: brown bears as vectors for polar bear alleles.

    Science.gov (United States)

    Hailer, Frank

    2015-03-01

    The dynamics and consequences of introgression can inform about numerous evolutionary processes. Biologists have therefore long been interested in hybridization. One challenge, however, lies in the identification of nonadmixed genotypes that can serve as a baseline for accurate quantification of admixture. In this issue of Molecular Ecology, Cahill et al. (2015) analyse a genomic data set of 28 polar bears, eight brown bears and one American black bear. Polar bear alleles are found to be introgressed into brown bears not only near a previously identified admixture zone on the Alaskan Admiralty, Baranof and Chichagof (ABC) Islands, but also far into the North American mainland. Elegantly contrasting admixture levels at autosomal and X chromosomal markers, Cahill and colleagues infer that male-biased dispersal has spread these introgressed alleles away from the Late Pleistocene contact zone. Compared to a previous study on the ABC Island population in which an Alaskan brown bear served as a putatively admixture-free reference, Cahill et al. (2015) utilize a newly sequenced Swedish brown bear as admixture baseline. This approach reveals that brown bears have been impacted by introgression from polar bears to a larger extent (up to 8.8% of their genome), than previously known, including the bear that had previously served as admixture baseline. No evidence for introgression of brown bear into polar bear is found, which the authors argue could be a consequence of selection. Besides adding new exciting pieces to the puzzle of polar/brown bear evolutionary history, the study by Cahill and colleagues highlights that wildlife genomics is moving from analysing single genomes towards a landscape genomics approach. © 2015 John Wiley & Sons Ltd.

  3. [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.