A DNA library from an individual Beta patellaris chromosome conferring nematode resistance obtained by microdissection of meiotic metaphase chromosomes

1992 ◽  
Vol 20 (3) ◽  
pp. 503-511 ◽  
Author(s):  
C. Jung ◽  
U. Claussen ◽  
B. Horsthemke ◽  
F. Fischer ◽  
R. G. Herrmann
Keyword(s):  
Nematode Resistance ◽  
Meiotic Metaphase ◽  
Metaphase Chromosomes ◽  
Dna Library ◽  
Beta Patellaris

Experiments on blocking and unblocking of first meiotic metaphase in eggs of the parthenogenetic stick insect Carausius morosus Br. (Phasmida, Insecta)

Development ◽  
1976 ◽  
Vol 36 (2) ◽  
pp. 383-394
Author(s):  
L. P. Pijnacker ◽  
M. A. Ferwerda
Keyword(s):  
Interphase Nucleus ◽  
Stick Insect ◽  
Meiotic Metaphase ◽  
Anterior Region ◽  
Egg Cell ◽  
Metaphase Chromosomes ◽  
Carausius Morosus ◽  
Cytoplasmic Factors ◽  
Activating Agent ◽  
Nuclear Behaviour

The eggs of the parthenogenetic stick insect Carausius morosus, which remain arrested in first meiotic metaphase until oviposition, must be activated in order to develop. The activating agent is oxygen from the air, which enters the egg cell through the micropyle. An exposure shorter than one minute is sufficient to release the blockage. In non-activated (micropyle-less) eggs the first metaphase chromosomes either degenerate or change into an interphase nucleus. This nucleus polyploidizes by endoreduplication, and then either degenerates or multiplies by amitosis. Similarly more generations of nuclei may arise resulting in a chaotic development. These nuclei survive better in the anterior region of the egg. The question of whether the cytoplasmic factors which control nuclear behaviour, also operate in eggs of C. morosus is discussed.

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).

Isolation of DNA markers linked to a beet cyst nematode resistance locus in Beta patellaris and Beta procumbens

1992 ◽  
Vol 235 (2-3) ◽  
pp. 432-440 ◽  
Author(s):  
E. M. J. Salentijn ◽  
N. N. Sandal ◽  
W. Lange ◽  
Th. S. M. De Bock ◽  
F. A. Krens ◽  
...  
Keyword(s):  
Dna Markers ◽  
Nematode Resistance ◽  
Cyst Nematode ◽  
Resistance Locus ◽  
Beta Procumbens ◽  
Beet Cyst Nematode ◽  
Beta Patellaris

Preparation of Mitotic and Meiotic Metaphase Chromosomes from Young Leaves and Flower Buds of Coccinia grandis

BIO-PROTOCOL ◽  
2016 ◽  
Vol 6 (7) ◽  
Author(s):  
Sangram Sinha ◽  
Kanika Karmakar ◽  
Ravi Devani ◽  
Jayeeta Banerjee ◽  
Rabindra Sinha ◽  
...  
Keyword(s):  
Meiotic Metaphase ◽  
Flower Buds ◽  
Metaphase Chromosomes ◽  
Coccinia Grandis ◽  
Young Leaves

Some Structural Features of Metaphase Chromosomes of Mice and Men

1967 ◽  
Vol 25 ◽  
pp. 190-191
Author(s):  
Godfrey C. Hoskins ◽  
Betty B. Hoskins
Keyword(s):  
Electron Microscopy ◽  
Electron Micrographs ◽  
Structural Features ◽  
Metaphase Chromosomes ◽  
The Future ◽  
Of Mice And Men ◽  
Mouse Cells ◽  
Human And Mouse

Metaphase chromosomes from human and mouse cells in vitro are isolated by micrurgy, fixed, and placed on grids for electron microscopy. Interpretations of electron micrographs by current methods indicate the following structural features.Chromosomal spindle fibrils about 200Å thick form fascicles about 600Å thick, wrapped by dense spiraling fibrils (DSF) less than 100Å thick as they near the kinomere. Such a fascicle joins the future daughter kinomere of each metaphase chromatid with those of adjacent non-homologous chromatids to either side. Thus, four fascicles (SF, 1-4) attach to each metaphase kinomere (K). It is thought that fascicles extend from the kinomere poleward, fray out to let chromosomal fibrils act as traction fibrils against polar fibrils, then regroup to join the adjacent kinomere.

Studies of metaphase chromosomes in the scanning transmission x-ray microscope: Image fidelity, radiation damage and specimen preparation

1992 ◽  
Vol 50 (2) ◽  
pp. 1038-1039
Author(s):  
Shawn Williams ◽  
Xiaodong Zhang ◽  
Susan Lamm ◽  
Jack Van’t Hof
Keyword(s):  
Visible Light ◽  
Radiation Damage ◽  
Cross Section ◽  
Imaging Techniques ◽  
Dose Range ◽  
Specimen Preparation ◽  
X Rays ◽  
Metaphase Chromosomes ◽  
X Ray ◽  
Scanning Transmission

The Scanning Transmission X-ray Microscope (STXM) is well suited for investigating metaphase chromosome structure. The absorption cross-section of soft x-rays having energies between the carbon and oxygen K edges (284 - 531 eV) is 6 - 9.5 times greater for organic specimens than for water, which permits one to examine unstained, wet biological specimens with resolution superior to that attainable using visible light. The attenuation length of the x-rays is suitable for imaging micron thick specimens without sectioning. This large difference in cross-section yields good specimen contrast, so that fewer soft x-rays than electrons are required to image wet biological specimens at a given resolution. But most imaging techniques delivering better resolution than visible light produce radiation damage. Soft x-rays are known to be very effective in damaging biological specimens. The STXM is constructed to minimize specimen dose, but it is important to measure the actual damage induced as a function of dose in order to determine the dose range within which radiation damage does not compromise image quality.

DNA sequence mapping in interphase and metaphase chromosomes by fluorescence in situ hybridization

1992 ◽  
Vol 50 (1) ◽  
pp. 496-497
Author(s):  
Barbara Trask ◽  
Susan Allen ◽  
Anne Bergmann ◽  
Mari Christensen ◽  
Anne Fertitta ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Dna Sequence ◽  
Dna Sequences ◽  
Dual Band ◽  
Nick Translation ◽  
Metaphase Chromosomes ◽  
Band Pass ◽  
Texas Red ◽  
Fluorescent Spot

Using fluorescence in situ hybridization (FISH), the positions of DNA sequences can be discretely marked with a fluorescent spot. The efficiency of marking DNA sequences of the size cloned in cosmids is 90-95%, and the fluorescent spots produced after FISH are ≈0.3 μm in diameter. Sites of two sequences can be distinguished using two-color FISH. Different reporter molecules, such as biotin or digoxigenin, are incorporated into DNA sequence probes by nick translation. These reporter molecules are labeled after hybridization with different fluorochromes, e.g., FITC and Texas Red. The development of dual band pass filters (Chromatechnology) allows these fluorochromes to be photographed simultaneously without registration shift.

Advances in imaging SIMS studies of stained and BrdU-labelled human metaphase chromosomes

1995 ◽  
Vol 53 ◽  
pp. 932-933
Author(s):  
R. Levi-Setti ◽  
J. M. Chabala ◽  
R. Espinosa ◽  
M. M. Le Beau
Keyword(s):  
High Performance ◽  
Secondary Ion Mass Spectrometry ◽  
Analytical Sensitivity ◽  
Metaphase Chromosomes ◽  
Banding Patterns ◽  
Sector Mass Spectrometer ◽  
Staining Methods ◽  
The University ◽  
Secondary Ion ◽  
Better Than

We have shown previously that isotope-labelled nucleotides in human metaphase chromosomes can be detected and mapped by imaging secondary ion mass spectrometry (SIMS), using the University of Chicago high resolution scanning ion microprobe (UC SIM). These early studies, conducted with BrdU- and 14C-thymidine-labelled chromosomes via detection of the Br and 28CN- (14C14N-> labelcarrying signals, provided some evidence for the condensation of the label into banding patterns along the chromatids (SIMS bands) reminiscent of the well known Q- and G-bands obtained by conventional staining methods for optical microscopy. The potential of this technique has been greatly enhanced by the recent upgrade of the UC SIM, now coupled to a high performance magnetic sector mass spectrometer in lieu of the previous RF quadrupole mass filter. The high transmission of the new spectrometer improves the SIMS analytical sensitivity of the microprobe better than a hundredfold, overcoming most of the previous imaging limitations resulting from low count statistics.

Sign in / Sign up

Export Citation Format

Share Document