Localization of translocation breakpoints in somatic metaphase chromosomes of barley

1994 ◽  
Vol 89-89 (2-3) ◽  
pp. 240-248 ◽  
Author(s):  
F. Marthe ◽  
G. Künzel
Keyword(s):  
Metaphase Chromosomes ◽  
Somatic Metaphase ◽  
Translocation Breakpoints

scholarly journals Panhandle Polymerase Chain Reaction Amplifies MLL Genomic Translocation Breakpoint Involving Unknown Partner Gene

Blood ◽  
1997 ◽  
Vol 90 (12) ◽  
pp. 4679-4686 ◽  
Author(s):  
Carolyn A. Felix ◽  
Caroline S. Kim ◽  
Maureen D. Megonigal ◽  
Diana J. Slater ◽  
Douglas H. Jones ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Lymphoblastic Leukemia ◽  
Repetitive Sequences ◽  
Translocation Breakpoint ◽  
Chromosome Band ◽  
Chain Reaction ◽  
Metaphase Chromosomes ◽  
Partner Gene ◽  
Translocation Breakpoints ◽  
Polymerase Chain

Abstract We used a new approach called panhandle polymerase chain reaction (PCR) to clone an MLL genomic translocation breakpoint in a case of acute lymphoblastic leukemia of infancy in which karyotype analysis was technically unsuccessful and did not show the translocation partner. Panhandle PCR amplified known MLL sequence 5′ of the breakpoint and 3′ sequence from the unknown partner gene from a DNA template with an intrastrand loop schematically shaped like a pan with a handle. The 7-kb panhandle PCR product contained the translocation breakpoint in MLL intron 8. The partner DNA included unique nonrepetitive sequences, Alu and mammalian apparent LTR-retrotransposon (MaLR) repetitive sequences, and a region of homology to expressed sequence tags. MaLR sequences have not been found before near leukemia-associated translocation breakpoints. The nonrepetitive sequences were not homologous to known partner genes of MLL. Screening of somatic cell hybrid and radiation hybrid lines by PCR and fluorescence in situ hybridization analysis of normal metaphase chromosomes mapped the partner DNA to chromosome band 4q21. Reverse transcriptase-PCR identified an MLL-AF-4 chimeric mRNA, indicating that panhandle PCR identified a fusion of MLL with a previously uncharacterized AF-4 intronic sequence. Panhandle PCR facilitates cloning translocation breakpoints and identifying unknown partner genes.

In situ localization of two repetitive DNA sequences to surface-spread pachytene chromosomes of rye

Genome ◽  
1992 ◽  
Vol 35 (4) ◽  
pp. 551-559 ◽  
Author(s):  
S. M. Albini ◽  
T. Schwarzacher
Keyword(s):  
In Situ Hybridization ◽  
Synaptonemal Complex ◽  
Dna Sequences ◽  
Meiotic Prophase ◽  
Hybridization Signal ◽  
Metaphase Chromosomes ◽  
Somatic Metaphase ◽  
Rdna Signal ◽  
Surface Spread

Surface-spread pollen mother cells at meiotic prophase from Secale cereale (rye) were used for fluorescent DNA:DNA in situ localization of two tandemly repeated DNA sequences: pTa71, a wheat rDNA clone, and pSc119.2, a cloned 120-bp repeat from rye heterochromatin. The fluorescent hybridization signal, consisting of many yellow-green dots, was closely associated with the bivalent axes, corresponding to the synaptonemal complex, and located in the surrounding chromatin. The rDNA signal was associated with one bivalent, the smallest of the seven, at a distance about 13% of the bivalent length from the telomere. This corresponded to the position of the nucleolar organizing region of silver-stained synaptonemal complexes analyzed under the electron microscope and published data for somatic metaphase chromosomes. The relative length of the axis covered with the rDNA signal is less than expected from somatic metaphases, but it corresponds more closely to the proportion of the sequences in the genome. The hybridization signal with the 120-bp repeat was located mainly at the telomeric regions of several bivalents that showed thickenings of the axis after DAPI staining, probably corresponding to somatic C-bands. These major and some minor intercalary sites agree with the distribution of the 120-bp repeat in somatic metaphase. Fluorescent in situ hybridization to plant surface-spread pachytene chromosomes, which can be obtained in large numbers, has great potential for studying meiotic prophase, high-resolution mapping of DNA sequences, and investigating the relationship of DNA sequences to the synaptonemal complex.Key words: in situ hybridization, cereals, pachytene, meiosis, synaptonemal complex, physical mapping.

scholarly journals AFFINITY DISTANCE VALUES AMONG SOMATIC METAPHASE CHROMOSOMES IN MAIZE

Genetics ◽  
1978 ◽  
Vol 88 (1) ◽  
pp. 181-199
Author(s):  
J D Horn ◽  
D B Walden
Keyword(s):  
Random Distribution ◽  
Maize Root ◽  
Root Tip ◽  
Metaphase Arrest ◽  
Metaphase Chromosomes ◽  
Somatic Metaphase ◽  
Chemical Agents ◽  
Differential Responses

ABSTRACT In maize root-tip metaphase preparations, all distances between two chromosomes were measured in 50 cells from each of seven stocks and in 30 from one stock; four were arrested with cold, two with 8-hydroxyquinoline, one with colchicine and one with monobromonaphthalene Standardized, affinity-distance values were calculated for all pairs of homologues and pairs of nonhomologues from each preparation. The homologues of pair X were the least separated, those of pair I the most separated in the cold-arrested stocks. All but pairs I and VIII were shown to be significantly different from the observed mean. The observed mean was less than but not significantly different from the theoretical value for a random distribution. The use of chemical agents for metaphase arrest increased the separation of homologues, except for pair I.—Eleven percent of the comparisons of nonhomologues from cold-arrested, as contrasted to none of the comparisons from the c-metaphase treatments, were significantly different from the theoretical talue for a random distribution. This was considered evidence for limited primary nonhomologue association in maize. Although there were specific, differential responses to the two arrest agents, the population of homologous pairs approached a random distribution only in chemically arrested stocks.—Primary homologue association was considered to be maintained by two mechanisms. the more common involving the micro-tubules and the second involving the nucleolus.—Interpretations are offered regarding the claims of somatic association in other species, especially man. The opportunity in maize for experimentally modifying distance values by cytogenetic techniques is discussed.

SOMATIC METAPHASE CHROMOSOMES IN GEOGRAPHIC ISOLATES OF THE CARROT RUST FLY, CHAMAEPSILA ROSAE (F.) (DIPTERA: PSILIDAE)

1957 ◽  
Vol 35 (3) ◽  
pp. 453-458 ◽  
Author(s):  
J. G. Robertson
Keyword(s):  
Chromosome Number ◽  
Comparative Study ◽  
X Chromosome ◽  
Sex Chromosomes ◽  
Prince Edward Island ◽  
Metaphase Chromosomes ◽  
Somatic Metaphase ◽  
Total Length ◽  
Total Complement ◽  
Secondary Constrictions

A comparative study of somatic metaphase complements of the carrot rust fly, Chamaepsila rosae (F.), from England, Prince Edward Island, Ontario, and British Columbia showed that the chromosome number is eight and that all chromosomes are metacentric. The means of the total complement length ranged from 50.8 to 53.5 and the lengths for chromosomal pairs I–IV averaged 36.5, 24.8, 22.3, and 16.5% of the total length respectively for the four regions. The sex chromosomes are the largest elements in the complement, the X chromosome being 36.5% of the total length and the Y 28.8%. The arm ratios for members X, Y, II, III, and IV are 1.34, 1.13, 1.57, 1.21, and 1.34 respectively. Secondary constrictions were both infrequent and irregular in location. The work emphasizes that much caution is necessary in analyzing metaphase chromosomes for taxonomic purposes.

scholarly journals DNA density in mitotic and meiotic metaphase chromosomes of plants and animals

1983 ◽  
Vol 63 (1) ◽  
pp. 173-179
Author(s):  
M.D. Bennett ◽  
J.S. Heslop-Harrison ◽  
J.B. Smith ◽  
J.P. Ward
Keyword(s):  
Animal Species ◽  
Three Dimensional ◽  
Meiotic Metaphase ◽  
Dna Amount ◽  
Metaphase Chromosomes ◽  
Somatic Metaphase ◽  
Thin Sectioning ◽  
Significant Difference ◽  
Dimensional Reconstruction ◽  
Dna Density

Studies of chromosome disposition at metaphase using serial thin-sectioning and three-dimensional reconstruction techniques have produced accurate estimates of the total volume of chromosomes per cell in 15 plant and two animal species. Comparing this character with the 4C DNA amount showed no indiction of systemic differences in DNA density between either organisms with widely different (greater than 200-fold) C values or different groups or organisms. For example, there was no significant difference between the density of DNA in somatic metaphase chromosomes of man (0.141 pg/micrometers3) and its mean in 14 angiosperm plant species (0.182 pg/micrometers3), or between four dicotyledons (0.180 pg/miocrometers3) and 10 monocotyledons (0.182 pg/micrometers3). However, evidence was found showing that DNA density can vary significantly within a species. Thus, although the total chromosome volume per cell was closely correlated (r greater than 0.97) with 4C DNA amount in somatic and meiotic cells, the density of DNA in metaphase chromosomes was significantly lower in meiocytes (0.131 pg/micrometers3) than in somatic metaphase cells (0.19 pg/micrometers3).

FLUORESCENT STAINING OF EUCHROMATIN AND HETEROCHROMATIN IN MAIZE (Zea mays)

1971 ◽  
Vol 13 (4) ◽  
pp. 811-815 ◽  
Author(s):  
J. D. Horn ◽  
D. B. Walden
Keyword(s):  
Zea Mays ◽  
Zea Mays L ◽  
Fluorescent Staining ◽  
Metaphase Chromosomes ◽  
Somatic Metaphase ◽  
Different Types ◽  
Exclusive Property

Somatic metaphase chromosomes of maize (Zea mays L.), including the largely heterochromatic supernumerary "B" and an abnormal No. 10, were stained with the fluorometric agent quinacrine mustard (QM).When the fluorescent regions of the chromosomes were compared to the known cytological positions of heterochromatin in maize, both euchromatic and heterochromatic regions showed fluorescence. Not all heterochromatin was fluorescent after staining with QM. We concluded that fluorescence with QM is not an exclusive property of heterochromatin. We also postulate that in maize there are at least two different types of heterochromatin, one which takes up the fluorometric agent QM readily and a second which does not.

scholarly journals Panhandle Polymerase Chain Reaction Amplifies MLL Genomic Translocation Breakpoint Involving Unknown Partner Gene

Blood ◽  
1997 ◽  
Vol 90 (12) ◽  
pp. 4679-4686 ◽  
Author(s):  
Carolyn A. Felix ◽  
Caroline S. Kim ◽  
Maureen D. Megonigal ◽  
Diana J. Slater ◽  
Douglas H. Jones ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Lymphoblastic Leukemia ◽  
Repetitive Sequences ◽  
Translocation Breakpoint ◽  
Chromosome Band ◽  
Chain Reaction ◽  
Metaphase Chromosomes ◽  
Partner Gene ◽  
Translocation Breakpoints ◽  
Polymerase Chain

We used a new approach called panhandle polymerase chain reaction (PCR) to clone an MLL genomic translocation breakpoint in a case of acute lymphoblastic leukemia of infancy in which karyotype analysis was technically unsuccessful and did not show the translocation partner. Panhandle PCR amplified known MLL sequence 5′ of the breakpoint and 3′ sequence from the unknown partner gene from a DNA template with an intrastrand loop schematically shaped like a pan with a handle. The 7-kb panhandle PCR product contained the translocation breakpoint in MLL intron 8. The partner DNA included unique nonrepetitive sequences, Alu and mammalian apparent LTR-retrotransposon (MaLR) repetitive sequences, and a region of homology to expressed sequence tags. MaLR sequences have not been found before near leukemia-associated translocation breakpoints. The nonrepetitive sequences were not homologous to known partner genes of MLL. Screening of somatic cell hybrid and radiation hybrid lines by PCR and fluorescence in situ hybridization analysis of normal metaphase chromosomes mapped the partner DNA to chromosome band 4q21. Reverse transcriptase-PCR identified an MLL-AF-4 chimeric mRNA, indicating that panhandle PCR identified a fusion of MLL with a previously uncharacterized AF-4 intronic sequence. Panhandle PCR facilitates cloning translocation breakpoints and identifying unknown partner genes.

In situ hybridization to somatic metaphase chromosomes of potato

1988 ◽  
Vol 76 (3) ◽  
pp. 420-424 ◽  
Author(s):  
R. G. F. Visser ◽  
R. Hoekstra ◽  
F. R. van der Leij ◽  
L. P. Pijnacker ◽  
B. Witholt ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Metaphase Chromosomes ◽  
Somatic Metaphase

INSECT CHROMOSOME BANDING: TECHNIQUE FOR G- AND Q-BANDING PATTERN IN THE MOSQUITO AEDES ALBOPICTUS

1975 ◽  
Vol 17 (2) ◽  
pp. 241-244 ◽  
Author(s):  
Gerald E. Steiniger ◽  
Asit B. Mukherjee
Keyword(s):  
Aedes Albopictus ◽  
Banding Pattern ◽  
Chromosome Banding ◽  
Banding Technique ◽  
Modified Technique ◽  
Metaphase Chromosomes ◽  
Somatic Metaphase

A modified technique is described for the production of clear G- and Q-bands of somatic metaphase chromosomes of the mosquito, Aedes albopictus Skuse.

Occurrence of G-banding in metaphase chromosomes of Encarsia berlesei (Hymenoptera: Aphelinidae)

Genome ◽  
1993 ◽  
Vol 36 (4) ◽  
pp. 662-667 ◽  
Author(s):  
Gaetano Odierna ◽  
Fulvio Baldanza ◽  
Gennaro Aprea ◽  
Ettore Olmo
Keyword(s):  
Rapid Identification ◽  
Insect Species ◽  
Metaphase Chromosomes ◽  
Somatic Metaphase

Well-defined G-bands were obtained on somatic metaphase chromosomes of Encarsia berlesei using trypsin and warm 2× SCC in sequence. The G-banded pattern allowed rapid identification of all five metacentric chromosomes, which appeared uniformly lighted when stained with DAPI fluorochrome dye. It is stressed that ageing affects G-banding in this insect species; in fact, good banded chromosomes were obtained on 1-month air-stored chromosomes. Evidence for asynchronous condensation on the chromosomes of this species is also provided.Key words: G-banding, chromosomes, insect, Encarsia.

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