Johannes Wienberg

Bio: Johannes Wienberg is an academic researcher from University of Cambridge. The author has contributed to research in topics: Karyotype & Cytogenetics. The author has an hindex of 41, co-authored 56 publications receiving 5990 citations. Previous affiliations of Johannes Wienberg include Santa Clara University & Ludwig Maximilian University of Munich.

Multicolor Spectral Karyotyping of Human Chromosomes

Abstract: The simultaneous and unequivocal discernment of all human chromosomes in different colors would be of significant clinical and biologic importance. Whole-genome scanning by spectral karyotyping allowed instantaneous visualization of defined emission spectra for each human chromosome after fluorescence in situ hybridization. By means of computer separation (classification) of spectra, spectrally overlapping chromosome-specific DNA probes could be resolved, and all human chromosomes were simultaneously identified.

The Promise of Comparative Genomics in Mammals

Abstract: Dense genetic maps of human, mouse, and rat genomes that are based on coding genes and on microsatellite and single-nucleotide polymorphism markers have been complemented by precise gene homolog alignment with moderate-resolution maps of livestock, companion animals, and additional mammal species. Comparative genetic assessment expands the utility of these maps in gene discovery, in functional genomics, and in tracking the evolutionary forces that sculpted the genome organization of modern mammalian species.

Multicolour spectral karyotyping of mouse chromosomes.

Abstract: Murine models of human carcinogenesis are exceedingly valuable tools to understand genetic mechanisms of neoplastic growth. The identification of recurrent chromosomal rearrangements by cytogenetic techniques serves as an initial screening test for tumour specific aberrations. In murine models of human carcinogenesis, however, karyotype analysis is technically demanding because mouse chromosomes are acrocentric and of similar size. Fluorescence in situ hybridization (FISH) with mouse chromosome specific painting probes can complement conventional banding analysis. Although sensitive and specific, FISH analyses are restricted to the visualization of only a few mouse chromosomes at a time. Here we apply a novel imaging technique that we developed recently for the visualization of human chromosomes to the simultaneous discernment of all mouse chromosomes. The approach is based on spectral imaging to measure chromosome-specific spectra after FISH with differentially labelled mouse chromosome painting probes. Utilizing a combination of Fourier spectroscopy, CCD-imaging and conventional optical microscopy, spectral imaging allows simultaneous measurement of the fluorescence emission spectrum at all sample points. A spectrum-based classification algorithm has been adapted to karyotype mouse chromosomes. We have applied spectral karyotyping (SKY) to chemically induced plasmocytomas, mammary gland tumours from transgenic mice overexpressing the c-myc oncogene and thymomas from mice deficient for the ataxia telangiectasia (Atm) gene. Results from these analyses demonstrate the potential of SKY to identify complex chromosomal aberrations in mouse models of human carcinogenesis.

Comparative Genome Organization of Vertebrates

Abstract: L. Andersson, Department of Animal Breeding and Genetics, Swedish University of Agricultural Science, Uppsala, Sweden; A. Archibald, Roslin Institute (Edinburgh), Roslin, Midlothian, EH25 9PS, Scotland, UK; M. Ashburner, Department of Genetics, University of Cambridge, Downing Street, Cambridge, CB2 3EH, UK; S. Audun, Department of Morphology, Genetics and Aquatic Biology, Norwegian College of Veterinary Medicine, PO Box 8146 Dept, N-0033 Oslo, Norway; W. Barendse, CSIRO, Division of Tropical Animal Production, Molecular Animal Genetics Centre, University of Queensland, St Lucia, 4072, Australia; J. Bitgood, Poultry Science Department, University of Wisconsin-Madison, 260 Animal Sciences Building, 1675 Observatory Drive, Madison, Wisconsin 53706-1284, USA; C. Bottema, Department of Animal Science, Waite Agricultural Research Institute. University of Adelaide, Glen Osmond, 5064, Australia; T. Broad, AgResearch, Invermay Agricultural Centre, Mosgiel, New Zealand; S. Brown, Department of Biochemistry and Molecular Genetics, St Mary's Hospital Medical School, Norfolk Place, London W2 1PG UK; D. Burt, Division of Molecular Biology, Roslin Institute, Midlothian, UK; C. Charlier, Department of Genetics, Faculty of Medicine, Veterinary, B43, B de Colonster, 20, 4000 Liege, Belgium; N. Copeland, ABL-Basic Research Program, NCI-Frederick Cancer Research & Development Center, Frederick, MD 21702, USA; S. Davis, Department of Animal Science, Texas A&M University, College Station, Texas 77843-2471, USA; M. Davisson, The Jackson Laboratory, 600 Main Street, Bar Harbor, Maine 04609 USA; J. Edwards, Department of Biochemistry, Oxford, UK; A. Eggen, ABS Global, Inc, 6908 River Road, DeForest, Wisconsin 53532, USA; G. Elgar, Molecular Genetics, Department of Medicine, Addenbrookes Hospital, Hills Road, Cambridge CB2 2QQ, UK; J.T. Eppig, The Jackson Laboratory, 600 Main Street, Bar Harbor, Maine 04609, USA; I. Franklin, CSIRO, Division of Animal Production, Locked Bag 1, Delivery Centre, Blacktown, 2148, Australia; P. Grewe, CSIRO Fisheries, GPO Box 1538, Hobart 7001, Australia; T. Gill III, S-705 Scaife Hall, Department of Pathology/University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA; J.A.M. Graves, School of Genetics and Human Variation, LaTrobe University, Bundoora 3083, Australia; R. Hawken, Centre for Animal Biotechnology, The School of Veterinary Sciences, The University of Melbourne 3052, Australia; J. Hetzel, CSIRO, Division of Tropical Animal Production, Molecular Animal Genetics Centre, University of Queensland, St Lucia 4072, Australia; A. Hilyard, The Jackson Laboratory, 600 Main Street, Bar Harbor, Maine 04609-1500 USA; H. Jacob, Massachusetts General Hospital-East, Cardiovascular Research Center, 149 13th Street, Charlestown, Massachusetts 92129 USA; L. Jaswinska, Queensland Institute of Medical Research, Bancroft Centre, Royal Brisbane Hospital, Lutwyche Road, Herston, Queensland, Australia; N. Jenkins, ABL-Basic Research Program, NCI Frederick Cancer Research & Development Center, Frederick, Maryland 21702 USA; H. Kunz, University of Pittsburgh, School of Medicine, Department of Pathology, Pittsburgh, Pennsylvania 15261, USA; G. Levan, Department of Genetics, Medicinaregatan 9C $41390 Goteborg, Sweden; O. Lie, Norwegian College of Veterinary Medicine, Department of Morphology, Genetics and Aquatic Biology, Division of Genetics, PO Box 8176, Dep, N-0033, Norway; L. Lyons, National Cancer Institute, LVC-FCRDC, Building 560, Frederick, Maryland 21702-1201 USA; P. Maccarone, Department of Genetics & Human Variation, School of Biological Sciences, LaTrobe University, Bundoora 3083, Australia; C. Mellersh, Clinical Division M-318, Fred Hutchinson Cancer Research Center, 1124 Columbia Street, Seattle, Washington 98104, USA; G. Montgomery, AgResearch Molecular Biology Unit, Department of Biochemistry, University of Ontago, PO Box 56, Dunedin, New Zealand; S. Moore, CSIRO, Division of Tropical Animal Production, Molecular Animal Genetics Centre, University of Queensland, St Lucia 4072, Australia; C. Moran, Department of Animal Science, University of Sydney 2006, Australia; D. Morizot, University of Texas, M.D. Anderson Cancer Center, Science Park, Research Division, Smithville, Texas 78957, USA; M. Neff, Department of Molecular and Cellular Biology, University of California, Berkeley, California 94720, USA; F. Nicholas, Department of Animal Science, University of Sydney 2006, Australia; S. O'Brien, Laboratory of Viral Carcinogenesis, National Cancer Institute, Building 560, Frederick, Maryland 21702-1201, USA; Y. Parsons, School of Biological Sciences, Macquarie University 2109, Australia; J. Peters, Mammalian Genetics Unit, Medical Research Council, Harwell, Didcot, Oxon OX11 ORD, UK; J. Postlethwait, Institute of Neuroscience, 1254 University of Oregon, Eugene, Oregon 97403-1254, USA; M. Raymond, Genetics Section, Laboratory of Viral Carcinogenests, National Cancer Institute-FCRDC, Frederick, Maryland 21702-1201, USA; M. Rothschild, Department of Animal Sciences, Iowa State University, 225 Kildee Hall, Ames, Iowa 50011, USA; L. Schook, Department of Veterinary PathoBiology, University of Minnesota, 295 Animal Science/Veterinary Medical Building 1988 Fitch Avenue, St Paul, Minnesota 55108, USA; Y. Sugimoto, Shirakawa Institute of Animal Genetics, Odakura, Nishigo, Nishi-shirakawa, Fukushima 961, Japan; C. Szpirer, Department de Biologie Moleculaire, Universite Libre de Bruxelles, Rue des Chevaux 67, B-1640 Rhode-St-Genese, Belgium; M. Tate, Sheep Genomics, AgResearch Invermay Agricultural Centre, Private Bag 50034, Mosgiel, New Zealand; J. Taylor, Department of Animal Science, Texas A&M University, College Station, Texas 77843-2471, USA; J. VandeBerg, Southwest Foundation for Biomedical Research, PO Box 760549, San Antonio, Texas 78245, USA; M. Wakefield, School of Genetics & Human Variation, LaTrobe University, Bundoora 3083, Australia; J. Wienberg, Department of Pathology, Cambridge University, Tennis Court Road, Cambridge CB2 1 QP, UK; J. Womack, Department of Veterinary Pathobiology, Texas A&M University, College Station, Texas 77843, USA.

Chromosome Painting: A Useful Art

Abstract: Chromosome 'painting' refers to the hybridization of fluorescently labeled chromosome-specific, composite probe pools to cytological preparations. Chromosome painting allows the visualization of individual chromosomes in metaphase or interphase cells and the identification of both numerical and structural chromosomal aberrations in human pathology with high sensitivity and specificity. In addition to human chromosome-specific probe pools, painting probes have become available for an increasing range of different species. They can be applied to cross-species comparisons as well as to the study of chromosomal rearrangements in animal models of human diseases. The simultaneous hybridization of multiple chromosome painting probes, each tagged with a specific fluorochrome or fluorochrome combination, has resulted in the differential color display of human (and mouse) chromosomes, i.e. color karyotyping. In this review, we will summarize recent developments of multicolor chromosome painting, describe applications in basic chromosome research and cytogenetic diagnostics, and discuss limitations and future directions.

Initial sequencing and analysis of the human genome.

Abstract: The human genome holds an extraordinary trove of information about human development, physiology, medicine and evolution. Here we report the results of an international collaboration to produce and make freely available a draft sequence of the human genome. We also present an initial analysis of the data, describing some of the insights that can be gleaned from the sequence.

Semiconductor Nanocrystals as Fluorescent Biological Labels

Abstract: Semiconductor nanocrystals were prepared for use as fluorescent probes in biological staining and diagnostics. Compared with conventional fluorophores, the nanocrystals have a narrow, tunable, symmetric emission spectrum and are photochemically stable. The advantages of the broad, continuous excitation spectrum were demonstrated in a dual-emission, single-excitation labeling experiment on mouse fibroblasts. These nanocrystal probes are thus complementary and in some cases may be superior to existing fluorophores.

Initial sequencing and comparative analysis of the mouse genome.

Abstract: The sequence of the mouse genome is a key informational tool for understanding the contents of the human genome and a key experimental tool for biomedical research. Here, we report the results of an international collaboration to produce a high-quality draft sequence of the mouse genome. We also present an initial comparative analysis of the mouse and human genomes, describing some of the insights that can be gleaned from the two sequences. We discuss topics including the analysis of the evolutionary forces shaping the size, structure and sequence of the genomes; the conservation of large-scale synteny across most of the genomes; the much lower extent of sequence orthology covering less than half of the genomes; the proportions of the genomes under selection; the number of protein-coding genes; the expansion of gene families related to reproduction and immunity; the evolution of proteins; and the identification of intraspecies polymorphism.

Quantum dot bioconjugates for imaging, labelling and sensing

Abstract: One of the fastest moving and most exciting interfaces of nanotechnology is the use of quantum dots (QDs) in biology. The unique optical properties of QDs make them appealing as in vivo and in vitro fluorophores in a variety of biological investigations, in which traditional fluorescent labels based on organic molecules fall short of providing long-term stability and simultaneous detection of multiple signals. The ability to make QDs water soluble and target them to specific biomolecules has led to promising applications in cellular labelling, deep-tissue imaging, assay labelling and as efficient fluorescence resonance energy transfer donors. Despite recent progress, much work still needs to be done to achieve reproducible and robust surface functionalization and develop flexible bioconjugation techniques. In this review, we look at current methods for preparing QD bioconjugates as well as presenting an overview of applications. The potential of QDs in biology has just begun to be realized and new avenues will arise as our ability to manipulate these materials improves.

Identification of a Cancer Stem Cell in Human Brain Tumors

Abstract: Most current research on human brain tumors is focused on the molecular and cellular analysis of the bulk tumor mass. However, there is overwhelming evidence in some malignancies that the tumor clone is heterogeneous with respect to proliferation and differentiation. In human leukemia, the tumor clone is organized as a hierarchy that originates from rare leukemic stem cells that possess extensive proliferative and self-renewal potential, and are responsible for maintaining the tumor clone. We report here the identification and purification of a cancer stem cell from human brain tumors of different phenotypes that possesses a marked capacity for proliferation, self-renewal, and differentiation. The increased self-renewal capacity of the brain tumor stem cell (BTSC) was highest from the most aggressive clinical samples of medulloblastoma compared with low-grade gliomas. The BTSC was exclusively isolated with the cell fraction expressing the neural stem cell surface marker CD133. These CD133+ cells could differentiate in culture into tumor cells that phenotypically resembled the tumor from the patient. The identification of a BTSC provides a powerful tool to investigate the tumorigenic process in the central nervous system and to develop therapies targeted to the BTSC.