22 Matching Results

Search Results

Advanced search parameters have been applied.

Applications of Strand-Specific in situ Hybridization

Description: This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Fluorescence in situ hybridization (FISH) is used to determine the location of specific DNA sequences on chromosomes. It is an effective tool in genomic mapping and is finding increasing use in medical diagnosis. A ''strand-specific'' version of FISH has been developed in the Life Sciences Division of LANL. The new procedure, named CO-FISH, reveals not only location but also the 5'-to-3'direction of a target sequence, such as the sense strand of a gene. This project was designed to investigate applications of the new technique. Strand-specific FISH was found to be useful and informative for genomic mapping of repetitive DNA sequences. The method provide a valuable new tool for investigating the mechanisms of aneuploidy inducing agents and the cytogenetic phenomena called lateral asymmetry. Finally, using strand-specific FISH, the authors were able to detect certain types of chromosome aberrations (isochromosomes, inversions and Robertsonian translocations) that can be difficult to observe with standard techniques.
Date: January 1, 1997
Creator: Goodwin, E.H.; Meyne, J.; Bailey, S.M.; Quigley, D.; Smith, L. & Tennyson, R.
Partner: UNT Libraries Government Documents Department

Validation of DNA probes for molecular cytogenetics by mapping onto immobilized circular DNA

Description: Fluorescence in situ hybridization (FISH) is a sensitive and rapid procedure to detect gene rearrangements in tumor cells using non-isotopically labeled DNA probes. Large insert recombinant DNA clones such as bacterial artificial chromosome (BAC) or P1/PAC clones have established themselves in recent years as preferred starting material for probe preparations due to their low rates of chimerism and ease of use. However, when developing probes for the quantitative analysis of rearrangements involving genomic intervals of less than 100kb, careful probe selection and characterization are of paramount importance. We describe a sensitive approach to quality control probe clones suspected of carrying deletions or for measuring clone overlap with near kilobase resolution. The method takes advantage of the fact that P1/PAC/BAC's can be isolated as circular DNA molecules, stretched out on glass slides and fine-mapped by multicolor hybridization with smaller probe molecules. Two examples demonstrate the application of this technique: mapping of a gene-specific {approx}6kb plasmid onto an unusually small, {approx}55kb circular P1 molecule and the determination of the extent of overlap between P1 molecules homologous to the human NF-?B2 locus. The relatively simple method presented here does not require specialized equipment and may thus find widespread applications in DNA probe preparation and characterization, the assembly of physical maps for model organisms or in studies on gene rearrangements.
Date: December 16, 2008
Creator: Greulich-Bode, Karin; Wang, Mei; Rhein, Andreas; Weier, Jingly & Weier, Heinz-Ulli
Partner: UNT Libraries Government Documents Department

Molecular cytogenetic characterization of a human thyroid cancercell line

Description: The incidence of papillary thyroid carcinoma (PTC) increases significantly after exposure of the head and neck region to ionizing radiation, yet we know neither the steps involved in malignant transformation of thyroid epithelium nor the specific carcinogenic mode of action of radiation. Such increased tumor frequency became most evident in children after the 1986 nuclear accident in Chernobyl, Ukraine. In the twelve years following the accident, the average incidence of childhood PTCs (chPTC) increased over one hundred-fold compared to the rate of about 1 tumor incidence per 10{sup 6} children per year prior to 1986. To study the etiology of radiation-induced thyroid cancer, we formed an international consortium to investigate chromosomal changes and altered gene expression in cases of post-Chernobyl chPTC. Our approach is based on karyotyping of primary cultures established from chPTC specimens, establishment of cell lines and studies of genotype-phenotype relationships through high resolution chromosome analysis, DNA/cDNA micro-array studies, and mouse xenografts that test for tumorigenicity. Here, we report the application of fluorescence in situ hybridization (FISH)-based techniques for the molecular cytogenetic characterization of a highly tumorigenic chPTC cell line, S48TK, and its subclones. Using chromosome 9 rearrangements as an example, we describe a new approach termed ''BAC-FISH'' to rapidly delineate chromosomal breakpoints, an important step towards a better understanding of the formation of translocations and their functional consequences.
Date: January 4, 2006
Creator: Weier, Heinz-Ulrich G.; Tuton, Tiffany B.; Ito, Yuko; Chu, LisaW.; Lu, Chung-Mei; Baumgartner, Adolf et al.
Partner: UNT Libraries Government Documents Department

Rapid evolution of a recently retroposed transcription factor YY2 in mammalian genomes

Description: YY2 was originally identified due to its unusual similarity to the evolutionarily well conserved, zinc-finger gene YY1. In this study, we have determined the evolutionary origin and conservation of YY2 using comparative genomic approaches. Our results indicate that YY2 is a retroposed copy of YY1 that has been inserted into another gene locus named Mbtps2 (membrane-bound transcription factor protease site 2). This retroposition is estimated to have occurred after the divergence of placental mammals from other vertebrates based on the detection of YY2 only in the placental mammals. The N-terminal and C-terminal regions of YY2 have evolved under different selection pressures. The N-terminal region has evolved at a very fast pace with very limited functional constraints whereas the DNA-binding, C-terminal region still maintains very similar sequence structure as YY1 and is also well conserved among placental mammals. In situ hybridizations using different adult mouse tissues indicate that mouse YY2 is expressed at relatively low levels in Purkinje and granular cells of cerebellum, and neuronal cells of cerebrum, but at very high levels in testis. The expression levels of YY2 is much lower than YY1, but the overall spatial expression patterns are similar to those of Mbtps2, suggesting a possible shared transcriptional control between YY2 and Mbtps2. Taken together, the formation and evolution of YY2 represent a very unusual case where a transcription factor was first retroposed into another gene locus encoding a protease and survived with different selection schemes and expression patterns.
Date: November 11, 2005
Creator: Luo, C; Lu, X; Stubbs, L & Kim, J
Partner: UNT Libraries Government Documents Department

Molecular cytogenetic analysis of human blastocysts andcytotrophoblasts by multi-color FISH and Spectra Imaging analyses

Description: Numerical chromosome aberrations in gametes typically lead to failed fertilization, spontaneous abortion or a chromosomally abnormal fetus. By means of preimplantation genetic diagnosis (PGD), we now can screen human embryos in vitro for aneuploidy before transferring the embryos to the uterus. PGD allows us to select unaffected embryos for transfer and increases the implantation rate in in vitro fertilization programs. Molecular cytogenetic analyses using multi-color fluorescence in situ hybridization (FISH) of blastomeres have become the major tool for preimplantation genetic screening of aneuploidy. However, current FISH technology can test for only a small number of chromosome abnormalities and hitherto failed to increase the pregnancy rates as expected. We are in the process of developing technologies to score all 24 chromosomes in single cells within a 3 day time limit, which we believe is vital to the clinical setting. Also, human placental cytotrophoblasts (CTBs) at the fetal-maternal interface acquire aneuploidies as they differentiate to an invasive phenotype. About 20-50% of invasive CTB cells from uncomplicated pregnancies were found aneuploidy, suggesting that the acquisition of aneuploidy is an important component of normal placentation, perhaps limiting the proliferative and invasive potential of CTBs. Since most invasive CTBs are interphase cells and possess extreme heterogeneity, we applied multi-color FISH and repeated hybridizations to investigate individual CTBs. In summary, this study demonstrates the strength of Spectral Imaging analysis and repeated hybridizations, which provides a basis for full karyotype analysis of single interphase cells.
Date: February 8, 2006
Creator: Weier, Jingly F.; Ferlatte, Christy; Baumgartner, Adolf; Jung,Christine J.; Nguyen, Ha-Nam; Chu, Lisa W. et al.
Partner: UNT Libraries Government Documents Department

Preaxial Polydactyly in Sost/Sostdc1 Double Knockouts

Description: In the United States, {approx}5% are born with congenital birth defects due to abnormal function of cellular processes and interactions. Sclerosteosis, a rare autosomal recessive disease, causes hyperostosis of the axial and appendicular skeleton, and patients present radial deviation, digit syndactyly, nail dysplasia, and overall high bone mineral density. Sclerosteosis is due to a loss of function of sclerostin (Sost). Sost is a Wnt (abbrev.) antagonist; when mutated, nonfunctional Sost results in hyperactive osteoblast activity which leads to abnormal high bone mass. Previous studies have shown that Sost overexpression in transgenic mice causes reduced bone mineral density and a variety of limb phenotypes ranging from lost, fused, and split phalanges. Consistent with clinical manifestations of Sclerosteosis, Sost knockout mice exhibit increased generalized bone mineral density and syndactyly of the digits. Sostdc1 is a paralog of Sost that has also been described as an antagonist of Wnt signaling, in developing tooth buds. Unlike Sost knockouts, Sostdc1 null mice do not display any limb abnormalities. To determine if Sost and Sostdc1 have redundant functions during limb patterning, we examined Sost; Sostdc1 mice determined that they exhibit a novel preaxial polydactyly phenotype with a low penetrance. LacZ staining, skeletal preparations, and in situ hybridization experiments were used to help characterize this novel phenotype and understand how this phenotype develops. We find Sost and Sostdc1 to have complementary expression patterns during limb development, and the loss of their expression alters the transcription of several key limb regulators, such as Fgf8, Shh and Grem.
Date: July 29, 2011
Creator: Yee, C M; Collette, N M & Loots, G G
Partner: UNT Libraries Government Documents Department

Chromosome-specific DNA Repeat Probes

Description: 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.
Date: March 16, 2006
Creator: Baumgartner, Adolf; Weier, Jingly Fung & Weier, Heinz-Ulrich G.
Partner: UNT Libraries Government Documents Department

Validation of DNA probes for molecular cytogenetics by mapping onto immobilized circular DNA

Description: Fluorescence in situ hybridization (FISH) is a sensitive and rapid procedure to detect gene rearrangements in tumor cells using non-isotopically labeled DNA probes. Large insert recombinant DNA clones such as bacterial artificial chromosome (BAC) or P1/PAC clones have established themselves in recent years as preferred starting material for probe preparations due to their low rates of chimerism and ease of use. However, when developing probes for the quantitative analysis of rearrangements involving genomic intervals of less than 100kb, careful probe selection and characterization are of paramount importance. We describe a sensitive approach to quality control probe clones suspected of carrying deletions or for measuring clone overlap with near kilobase resolution. The method takes advantage of the fact that P1/PAC/BAC's can be isolated as circular DNA molecules, stretched out on glass slides and fine-mapped by multicolor hybridization with smaller probe molecules. Two examples demonstrate the application of this technique: mapping of a gene-specific {approx}6kb plasmid onto an unusually small, {approx}55kb circular P1 molecule and the determination of the extent of overlap between P1 molecules homologous to the human NF-{kappa}B2 locus. The relatively simple method presented here does not require specialized equipment and may thus find widespread applications in DNA probe preparation and characterization, the assembly of physical maps for model organisms or in studies on gene rearrangements.
Date: December 4, 2008
Creator: Greulich-Bode, Karin M.; Wang, Mei; Rhein, Andreas P.; Weier, Jingly F. & Weier, Heinz-Ulli G.
Partner: UNT Libraries Government Documents Department

Human cDNA mapping using fluorescence in situ hybridization. Final progress report, April 1, 1994--July 31, 1997

Description: The ultimate goal of this research is to generate and apply novel technologies to speed completion and integration of the human genome map and sequence with biomedical problems. To do this, techniques were developed and genome-wide resources generated. This includes a genome-wide Mapped and Integrated BAC/PAC Resource that has been used for gene finding, map completion and anchoring, breakpoint definition and sequencing. In the last period of the grant, the Human Mapped BAC/PAC Resource was also applied to determine regions of human variation and to develop a novel paradigm of primate evolution through to humans. Further, in order to more rapidly evaluate animal models of human disease, a BAC Map of the mouse was generated in collaboration with the MTI Genome Center, Dr. Bruce Birren.
Date: December 31, 1997
Creator: Korenberg, J.R.
Partner: UNT Libraries Government Documents Department

A sequence-based survey of the complex structural organization of tumor genomes

Description: The genomes of many epithelial tumors exhibit extensive chromosomal rearrangements. All classes of genome rearrangements can be identified using End Sequencing Profiling (ESP), which relies on paired-end sequencing of cloned tumor genomes. In this study, brain, breast, ovary and prostate tumors along with three breast cancer cell lines were surveyed with ESP yielding the largest available collection of sequence-ready tumor genome breakpoints and providing evidence that some rearrangements may be recurrent. Sequencing and fluorescence in situ hybridization (FISH) confirmed translocations and complex tumor genome structures that include coamplification and packaging of disparate genomic loci with associated molecular heterogeneity. Comparison of the tumor genomes suggests recurrent rearrangements. Some are likely to be novel structural polymorphisms, whereas others may be bona fide somatic rearrangements. A recurrent fusion transcript in breast tumors and a constitutional fusion transcript resulting from a segmental duplication were identified. Analysis of end sequences for single nucleotide polymorphisms (SNPs) revealed candidate somatic mutations and an elevated rate of novel SNPs in an ovarian tumor. These results suggest that the genomes of many epithelial tumors may be far more dynamic and complex than previously appreciated and that genomic fusions including fusion transcripts and proteins may be common, possibly yielding tumor-specific biomarkers and therapeutic targets.
Date: April 3, 2008
Creator: Collins, Colin; Raphael, Benjamin J.; Volik, Stanislav; Yu, Peng; Wu, Chunxiao; Huang, Guiqing et al.
Partner: UNT Libraries Government Documents Department

Evolutionary expansion and divergence in a large family of primate-specific zinc finger transcription factor genes

Description: Although most genes are conserved as one-to-one orthologs in different mammalian orders, certain gene families have evolved to comprise different numbers and types of protein-coding genes through independent series of gene duplications, divergence and gene loss in each evolutionary lineage. One such family encodes KRAB-zinc finger (KRAB-ZNF) genes, which are likely to function as transcriptional repressors. One KRAB-ZNF subfamily, the ZNF91 clade, has expanded specifically in primates to comprise more than 110 loci in the human genome, yielding large gene clusters in human chromosomes 19 and 7 and smaller clusters or isolated copies at other chromosomal locations. Although phylogenetic analysis indicates that many of these genes arose before the split between old world monkeys and new world monkeys, the ZNF91 subfamily has continued to expand and diversify throughout the evolution of apes and humans. The paralogous loci are distinguished by sequence divergence within their zinc finger arrays indicating a selection for proteins with different DNA binding specificities. RT-PCR and in situ hybridization data show that some of these ZNF genes can have tissue-specific expression patterns, however many KRAB-ZNFs that are near-ubiquitous could also be playing very specific roles in halting target pathways in all tissues except for a few, where the target is released by the absence of its repressor. The number of variant KRAB-ZNF proteins is increased not only because of the large number of loci, but also because many loci can produce multiple splice variants, which because of the modular structure of these genes may have separate and perhaps even conflicting regulatory roles. The lineage-specific duplication and rapid divergence of this family of transcription factor genes suggests a role in determining species-specific biological differences and the evolution of novel primate traits.
Date: September 28, 2005
Creator: Hamilton, A T; Huntley, S; Tran-Gyamfi, M; Baggott, D; Gordon, L & Stubbs, L
Partner: UNT Libraries Government Documents Department

TECHNICAL REPORT

Description: Because this DOE grant was abruptly terminated without warning, this group was not able to accomplish the insertion of the biosensor genes into the mouse lines. They have been able to generate some of the mouse lines but have not been able to complete the ones that would give them the model systems that would allow them to investigate metastasis real-time in living tumors at the cellular level. Nonetheless, until the loss of funding, they have made progress in applications of the equipment to biological problems involving RNA and protein movement in living cells. The following products were delivered: (1) Imaging of gene expression in living cells and tissues, Singer RH, Lawrence DS, Ovryn B, Condeelis J, J Biomed Optics 10:0514061-0514069, 2005. This paper describes the method for activating single genes within cells and tissues. (2) Single Cell Gene Expression Profiling: Multiplexed Expression Fluorescence in situ Hybridization (FISH): Application to the Analysis of Cultured Cells. Levsky JM, Braut SA, Singer RH, Cell Biology: A Laboratory Handbook Volume 4, eds Celis JE, et al, 121-130. Academic Press, 2005. This paper describes the methodology for single cell expression profiling in tissues. (3) Spatial regulation of beta-actin translation by Src-dependent phosphorylation of ZBP1, Huttelmaier S, Zenklusen D, Lederer M, Dictenberg J, Lorenz M, Meng X, Bassell GJ, Condeelis J, Singer RH, Nature 438:512-515, 2005. This paper describes the mechanism by which the translational repressor of actin mRNA ZBP1 can effect regulation of cell motility and metastasis. (4) Visualization of mRNA translation in living cells, Rodriguez AJ, Shenoy SM, Singer RH, Condeelis J, J Cell Biol 175:67-76, 2006. This work describes a method to visualize mRNA translation in single cells. (5) Imaging mRNA movement from transcription sites to translation sites, Rodriguez AJ, Condeelis J, Singer RH, Dictenberg JB, Semin Cell Dev Biol 18:202-208, 2007. ...
Date: October 11, 2007
Creator: SINGER, DR. ROBERT
Partner: UNT Libraries Government Documents Department

A BAC-based physical map of the Drosophila buzzatii genome

Description: Large-insert genomic libraries facilitate cloning of large genomic regions, allow the construction of clone-based physical maps and provide useful resources for sequencing entire genomes. Drosophilabuzzatii is a representative species of the repleta group in the Drosophila subgenus, which is being widely used as a model in studies of genome evolution, ecological adaptation and speciation. We constructed a Bacterial Artificial Chromosome (BAC) genomic library of D. buzzatii using the shuttle vector pTARBAC2.1. The library comprises 18,353 clones with an average insert size of 152 kb and a {approx}18X expected representation of the D. buzzatii euchromatic genome. We screened the entire library with six euchromatic gene probes and estimated the actual genome representation to be {approx}23X. In addition, we fingerprinted by restriction digestion and agarose gel electrophoresis a sample of 9,555 clones, and assembled them using Finger Printed Contigs (FPC) software and manual editing into 345 contigs (mean of 26 clones per contig) and 670singletons. Finally, we anchored 181 large contigs (containing 7,788clones) to the D. buzzatii salivary gland polytene chromosomes by in situ hybridization of 427 representative clones. The BAC library and a database with all the information regarding the high coverage BAC-based physical map described in this paper are available to the research community.
Date: March 18, 2005
Creator: Gonzalez, Josefa; Nefedov, Michael; Bosdet, Ian; Casals, Ferran; Calvete, Oriol; Delprat, Alejandra et al.
Partner: UNT Libraries Government Documents Department

Identification of a third protein 4.1 tumor suppressor, protein 4.1R, in meningioma pathogenesis

Description: Meningiomas are common tumors of the central nervous system, however, the mechanisms under lying their pathogenesis are largely undefined. Two members of the Protein 4.1 super family, the neuro fibromatosis 2 (NF2) gene product (merlin/schwannomin) and Protein 4.1B have been implicated as meningioma tumor suppressors. In this report, we demonstrate that another Protein 4.1 family member, Protein 4.1R, also functions as a meningioma tumor suppressor. Based on the assignment of the Protein 4.1R gene to chromosome 1p32-36, a common region of deletion observed in meningiomas, we analyzed Protein 4.1R expression in meningioma cell lines and surgical tumor specimens. We observed loss of Protein 4.1R protein expression in two meningioma cell lines (IOMM-Lee, CH157-MN) by Western blotting as well as in 6 of 15 sporadic meningioma as by immuno histo chemistry (IHC). Analysis of a subset of these sporadic meningiomas by fluorescent in situ hybridization (FISH) with a Protein 4.1R specific probe demonstrated 100 percent concordance with the IHC results. In support of a meningioma tumor suppressor function, over expression of Protein 4.1R resulted in suppression of IOMM-Lee and CH157MN cell proliferation. Similar to the Protein 4.1B and merlin meningioma tumor suppressors, Protein 4.1R localization in the membrane fraction increased significantly under conditions of growth arrest in vitro. Lastly, Protein 4.1R interacted with some known merlin/Protein 4.1B interactors such as CD44 and bII-spectrin, but did not associate with the Protein 4.1B interactors 14-3-3 and PRMT3 or the merlin binding proteins SCHIP-1 and HRS. Collectively, these results suggest that Protein 4.1R functions as an important tumor suppressor important in the molecular pathogenesis of meningioma.
Date: June 11, 2003
Creator: Robb, Victoria A.; Li, Wen; Gascard, Philippe; Perry, Arie; Mohandas, Narla & Gutmann, David H.
Partner: UNT Libraries Government Documents Department

Chromosomal mosaicism in mouse two-cell embryos after paternal exposure to acrylamide

Description: Chromosomal mosaicism in human preimplantation embryos is a common cause ofspontaneous abortions, however, our knowledge of its etiology is limited. We used multicolor fluorescence in situ hybridization (FISH) painting to investigate whether paternally-transmitted chromosomal aberrations result in mosaicism in mouse 2-cell embryos. Paternal exposure to acrylamide, an important industrial chemical also found in tobacco smoke and generated during the cooking process of starchy foods, produced significant increases in chromosomally defective 2-cell embryos, however, the effects were transient primarily affecting the postmeiotic stages of spermatogenesis. Comparisons with our previous study of zygotes demonstrated similar frequencies of chromosomally abnormal zygotes and 2-cell embryos suggesting that there was no apparent selection against numerical or structural chromosomal aberrations. However, the majority of affected 2-cell embryos were mosaics showing different chromosomal abnormalities in the two blastomeric metaphases. Analyses of chromosomal aberrations in zygotes and 2-cell embryos showed a tendency for loss of acentric fragments during the first mitotic division ofembryogenesis, while both dicentrics and translocations apparently underwent propersegregation. These results suggest that embryonic development can proceed up to the end of the second cell cycle of development in the presence of abnormal paternal chromosomes and that even dicentrics can persist through cell division. The high incidence of chromosomally mosaic 2-cell embryos suggests that the first mitotic division of embryogenesis is prone to missegregation errors and that paternally-transmitted chromosomal abnromalities increase the risk of missegregation leading to embryonic mosaicism.
Date: October 14, 2008
Creator: Marchetti, Francesco; Bishop, Jack; Lowe, Xiu & Wyrobek, Andrew J
Partner: UNT Libraries Government Documents Department

Somatic genomic variations in extra-embryonic tissues

Description: In the mature chorion, one of the membranes that exist during pregnancy between the developing fetus and mother, human placental cells form highly specialized tissues composed of mesenchyme and floating or anchoring villi. Using fluorescence in situ hybridization, we found that human invasive cytotrophoblasts isolated from anchoring villi or the uterine wall had gained individual chromosomes; however, chromosome losses were detected infrequently. With chromosomes gained in what appeared to be a chromosome-specific manner, more than half of the invasive cytotrophoblasts in normal pregnancies were found to be hyperdiploid. Interestingly, the rates of hyperdiploid cells depended not only on gestational age, but were strongly associated with the extraembryonic compartment at the fetal-maternal interface from which they were isolated. Since hyperdiploid cells showed drastically reduced DNA replication as measured by bromodeoxyuridine incorporation, we conclude that aneuploidy is a part of the normal process of placentation potentially limiting the proliferative capabilities of invasive cytotrophoblasts. Thus, under the special circumstances of human reproduction, somatic genomic variations may exert a beneficial, anti-neoplastic effect on the organism.
Date: May 21, 2010
Creator: Weier, Jingly F.; Ferlatte, Christy & Weier, Heinz-Ulli G.
Partner: UNT Libraries Government Documents Department

Induction of Genomic Instability In Vivo by Low Doses of 137Cs gamma rays

Description: The overall goal of this project is to determine if low doses (below or equal to the level traditionally requiring human radiation protection, i.e. less than or equal to 10 cGy) of low LET radiation can induce genomic instability. The magnitude of genomic instability was measured as delayed chromosome instability in bone marrow cells of exposed mice with different levels of endogenous DNA-dependent protein kinase catalytic subunit (DNA-PKcs) activity, i.e. high (C57BL/6J mice), intermediate (BALB/cJ mice), and extremely low (Scid mice). In addition, at early time points (1 and 4 hrs) following irradiation, levels of activation of nuclear factor-kappa B (NF-{kappa}B), a transcription factor known to be involved in regulating the expression of genes responsible for cell protection following stimuli, were measured in these cells. Bone marrow cells were collected at different times following irradiation, i.e. 1 hr, 4 hrs, 1 month, and 6 months. A total of five mice per dose per strain were sacrificed at each time point for sample collection. As a result, a total of 80 mice from each strain were used. The frequency and the type of metaphase chromosome aberrations in bone marrow cells collected from exposed mice at different times following irradiation were used as markers for radiation-induced genomic instability. A three-color fluorescence in situ hybridization (FISH) protocol for mouse chromosomes 1, 2, and 3 was used for the analysis of delayed stable chromosomal aberrations in metaphase cells. All other visible chromatid-type aberrations and gross structural abnormalities involving non-painted chromosomes were also evaluated on the same metaphase cells used for scoring the stable chromosomal aberrations of painted chromosomes. Levels of nuclear factor-kappa B (NF-{kappa}B) activation were also determined in cells at 1 and 4 hrs following irradiation (indicative of early responses).
Date: January 6, 2006
Creator: Rithidech, Kanokporn; Simon, Sanford, R. & Whorton, Elbert, B.
Partner: UNT Libraries Government Documents Department

In situ quantification of genomic instability in breast cancer progression

Description: Genomic instability is a hallmark of breast and other solid cancers. Presumably caused by critical telomere reduction, GI is responsible for providing the genetic diversity required in the multi-step progression of the disease. We have used multicolor fluorescence in situ hybridization and 3D image analysis to quantify genomic instability cell-by-cell in thick, intact tissue sections of normal breast epithelium, preneoplastic lesions (usual ductal hyperplasia), ductal carcinona is situ or invasive carcinoma of the breast. Our in situ-cell by cell-analysis of genomic instability shows an important increase of genomic instability in the transition from hyperplasia to in situ carcinoma, followed by a reduction of instability in invasive carcinoma. This pattern suggests that the transition from hyperplasia to in situ carcinoma corresponds to telomere crisis and invasive carcinoma is a consequence of telomerase reactivation afertelomere crisis.
Date: May 15, 2003
Creator: Ortiz de Solorzano, Carlos; Chin, Koei; Gray, Joe W. & Lockett, Stephen J.
Partner: UNT Libraries Government Documents Department

Dissection of Molecular Mechanisms Regulating Protein Body Formation in Maize Endosperm - DE-FG03-95-ER20183 B139

Description: Dissection of Molecular Mechanisms Regulating Protein Body Formation in Maize Endosperm - DE-FG03-95-ER20183 Final Technical Report and Patent Summary Dr. Brian A. Larkins, Department of Plant Sciences, University of Arizona, Tucson, AZ 85721 Endosperm texture is an important quality trait in maize, as it influences the shipping characteristics of the grain, its susceptibility to insects, the yield of grits from dry milling, energy costs during wet milling, and the baking and digestibility properties of the flour. There appears to be a causal relationship between kernel hardness and the formation of zein-containing protein bodies, as mutations affecting protein body number and structure are associated with a soft, starchy kernel. In this project we used a variety of approaches to better understand this relationship and investigate the molecular and biochemical changes associated with starchy endosperm mutants. We characterized the distribution of zein mRNAs on endosperm rough endoplasmic reticulum (RER) membranes and the interactions between zein proteins, as each of these could influence the structure of protein bodies. Based on in situ hybridization, mRNAs encoding the 22-kD alpha- and 27-kD gamma-zeins are randomly distributed on RER; hence, mRNA targeting does not appear to influence the formation of protein bodies. Investigation of the interactions between zein proteins (alpha, beta, gamma, delta) with the yeast two-hybrid system showed that interactions between the 19- and 22-alpha-zeins are relatively weak, although each of them interacted strongly with the 10-kD delta-zein. Strong interactions were detected between the alpha- and delta-zeins and the 16-kD gamma- and 15-kD beta-zeins; however, the 50-kD and 27-kD gamma-zeins did not interact detectably with the alpha- and delta-zein proteins. The NH2- and COOH-terminal domains of the 22-kD alpha-zein were found to interact most strongly with the 15-kD beta- and 16-kD gamma-zeins, suggesting the 16-kD and 15-kD proteins bind and assemble alpha-zeins in protein bodies. ...
Date: March 21, 2003
Creator: Larkins, Brian A.
Partner: UNT Libraries Government Documents Department

Chromosomal Rainbows detect Oncogenic Rearrangements of Signaling Molecules in Thyroid Tumors

Description: Altered signal transduction can be considered a hallmark of many solid tumors. In thyroid cancers the receptor tyrosine kinase (rtk) genes NTRK1 (Online Mendelian Inheritance in Man = OMIM *191315, also known as 'TRKA'), RET ('Rearranged during Transfection protooncogene', OMIM *164761) and MET (OMIM *164860) have been reported as activated, rearranged or overexpressed. In many cases, a combination of cytogenetic and molecular techniques allows elucidation of cellular changes that initiate tumor development and progression. While the mechanisms leading to overexpression of the rtk MET gene remain largely unknown, a variety of chromosomal rearrangements of the RET or NTKR1 gene could be demonstrated in thyroid cancer. Abnormal expressions in these tumors seem to follow a similar pattern: the rearrangement translocates the 3'-end of the rtk gene including the entire catalytic domain to an expressed gene leading to a chimeric RNA and protein with kinase activity. Our research was prompted by an increasing number of reports describing translocations involving ret and previously unknown translocation partners. We developed a high resolution technique based on fluorescence in situ hybridization (FISH) to allow rapid screening for cytogenetic rearrangements which complements conventional chromosome banding analysis. Our technique applies simultaneous hybridization of numerous probes labeled with different reporter molecules which are distributed along the target chromosome allowing the detection of cytogenetic changes at near megabase-pair (Mbp) resolution. Here, we report our results using a probe set specific for human chromosome 10, which is altered in a significant portion of human thyroid cancers (TC's). While rendering accurate information about the cytogenetic location of rearranged elements, our multi-locus, multi-color analysis was developed primarily to overcome limitations of whole chromosome painting (WCP) and chromosome banding techniques for fine mapping of breakpoints in papillary thyroid cancer (PTC).
Date: August 19, 2010
Creator: O'Brien, Benjamin; Jossart, Gregg H.; Ito, Yuko; Greulich-Bode, Karin M.; Weier, Jingly F.; Munne, Santiago et al.
Partner: UNT Libraries Government Documents Department

Molecular stress response in the CNS of mice after systemic exposureto interferon-alpha, ionizing radiation and ketamine

Description: We previously showed that the expression of troponin T1 (Tnnt 1) was induced in the central nervous system (CNS) of adultmice 30 min after treatment with ketamine, a glutamate N-methyl-D-aspartic acid (NMDA) receptor antagonist. We hypothesized that Tnnt 1 expression may be an early molecular biomarker of stress response in the CNS of mice. To further evaluate this hypothesis, we investigated the regional expression of Tnnt 1 in the mouse brain using RNA in situ hybridization 4 h after systemic exposure to interferon-a (IFN-a) and gamma ionizing radiation, both of which have be associated with wide ranges of neuropsychiatric complications. Adult B6C3F1 male mice were treated with either human IFN-a (a single i.p. injection at 1 x 105 IU/kg) or whole body gamma-radiation (10 cGy or 2 Gy). Patterns of Tnnt 1 transcript expression were compared in various CNS regions after IFN-a, radiation and ketamine treatments (previous study). Tnnt 1 expression was consistently induced in pyramidal neurons of cerebral cortex and hippocampus after all treatment regimens including 10 cGy of ionizing radiation. Regional expression of Tnnt 1 was induced in Purkinje cells of cerebellum after ionizing radiation and ketamine treatment; but not after IFN-a treatment. None of the three treatments induced Tnnt 1 expression in glial cells. The patterns of Tnnt 1 expression in pyramidal neurons of cerebral cortex andhippocampus, which are both known to play important roles in cognitive function, memory and emotion, suggest that the expression of Tnnt 1 may be an early molecular biomarker of induced CNS stress.
Date: March 3, 2009
Creator: Lowe, Xiu R.; Marchetti, Francesco; Lu, Xiaochen & Wyrobek, Andrew J.
Partner: UNT Libraries Government Documents Department

A system for combined three-dimensional morphological and molecular analysis of thick tissue specimens

Description: We present a new system for simultaneous morphological and molecular analysis of thick tissue samples. The system is composed of a computer assisted microscope and a JAVA-based image display, analysis and visualization program that allows acquisition, annotation, meaningful storage, three-dimensional reconstruction and analysis of structures of interest in thick sectioned tissue specimens. We describe the system in detail and illustrate its use by imaging, reconstructing and analyzing two complete tissue blocks which were differently processed and stained. One block was obtained from a ductal carcinoma in situ (DCIS) lumpectomy specimen and stained alternatively with Hematoxilyn and Eosin (H&E), and with a counterstain and fluorescence in situ hybridization (FISH) to the ERB-B2 gene. The second block contained a fully sectioned mammary gland of a mouse, stained for Histology with H&E. We show how the system greatly reduces the amount of interaction required for the acquisition and analysis and is therefore suitable for studies that require morphologically driven, wide scale (e.g., whole gland) analysis of complex tissue samples or cultures.
Date: April 25, 2002
Creator: Fernandez-Gonzalez, Rodrigo; Jones, Arthur; Garcia-Rodriguez, Enrique; Yuan Chen, Ping; Idica, Adam; Lockett, Stephen J. et al.
Partner: UNT Libraries Government Documents Department