Mechanisms of chromosome banding

Comings, David E.; Avelino, Evangelita

doi:10.1016/0014-4827(74)90674-0

Cited by 68 publications

(26 citation statements)

References 11 publications

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“…The typical toromere was always located at the distal end of the microchromosome. It is well known that quinacrine-bright fluorescence is often associated with constitutive heterochromatin containing repetitious AT-rich DNA (ELLISON and BARR 1972;CoMINGS et al 1975). The heterochromatic nature of the toromere was also confirmed in our experiments by applying a differential staining to polytene chromosomes by treatment with acridine orange after mild acid hydrolysis.…”

Section: Resultssupporting

confidence: 59%

The Molecular Nature of the Toromere inDrosophila LummeiHackman and its role in Chromosome Behavior

Евгеньев¹,

Stepanova²,

Levin³

et al. 1983

Caryologia

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SUMMARY -The toromere previously found by other workers in the distal end of the sixth chromosome (microchromosome) of D. limmei was studied using differential staining of Drosophila lummei giant chromosomes. The toromere which was first described as a quinacrine-bright structure appears as a C-positive body. Quantitative cytofluorometric analysis showed highly significant increase in toromeric DNA under low temperature conditions. In situ hybridization of 1 25I nick-translated D. virilis sDNA (all three satellites were included in the sample) with polytene chromosomes of D. lummei larvae cultured at 12° C revealed no label incorporation into toromere region. However in situ hybridization of 3H-RNA complementary to highly repetitious DNA of D. lummei and D. virilis (C 0 t = 10-q0-2 ) with polytene chromosomes of the larvae cultured at 12° C coupled with banding studies enable us to conclude that the toromere probably contains an AT-rich repeated DNA. A well-developed toromere in the sixth chromosome of D. lummei was also demonstrated at normal temperature (25° C) in interspecific hybrids. The role of the toromere structure in the mitotic behavior of microchromosomes and their replication pattern is discussed.

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Section: Resultssupporting

confidence: 59%

The Molecular Nature of the Toromere inDrosophila LummeiHackman and its role in Chromosome Behavior

Евгеньев¹,

Stepanova²,

Levin³

et al. 1983

Caryologia

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“…QA has been used extensively in cytology for staining so called Q-bands in condensed chromosomes (9,10). It is also used to differentiate between Y and X chromosomes because Y chromosome apparently stains much brighter than the X chromosome.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of acridine orange, LysoTracker Red, and quinacrine as fluorescent probes for long‐term tracking of acidic vesicles

2014

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Acidic vesicles can be imaged and tracked in live cells after staining with several low molecular weight fluorescent probes, or with fluorescently labeled proteins. Three fluorescent dyes, acridine orange, LysoTracker Red DND-99, and quinacrine, were evaluated as acidic vesicle tracers for confocal fluorescence imaging and quantitative analysis. The stability of fluorescent signals, achievable image contrast, and phototoxicity were taken into consideration. The three tested tracers exhibit different advantages and pose different problems in imaging experiments. Acridine orange makes it possible to distinguish acidic vesicles with different internal pH but is fairly phototoxic and can cause spectacular bursts of the dye-loaded vesicles. LysoTracker Red is less phototoxic but its rapid photobleaching limits the range of useful applications considerably. We demonstrate that quinacrine is most suitable for long-term imaging when a high number of frames is required. This capacity made it possible to trace acidic vesicles for several hours, during a process of drug-induced apoptosis. An ability to record the behavior of acidic vesicles over such long periods opens a possibility to study processes like autophagy or long-term effects of drugs on endocytosis and exocytosis. V C 2014International Society for Advancement of Cytometry

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“…For some cultures significantly higher DNA values were observed for 1 of the 2 techniques These discrepancies may have resulted from pigments or other cell constituents quenching or contributing background fluorescence to one of the fluorochromes, or from the known dependence of H33258 on the base composition of DNA. Fluorescence of H33258 is stronger with A.Trich DNA than with G-C-rich DNA (Weisblum & Haenssler 1974, Comings 1975. Therefore, variations in DNA measured with H33258 may have reflected changes in the base composition of the samples relative to a standard, in this case 60 % (A+T) calf thymus DNA (Comings 1975).…”

Section: Discussionmentioning

confidence: 99%

“…EthDi may have displaced H33258 from DNA as suggested by a 20 nm shift in the diminished H33258 emission peak which corresponded to the free fluorochrome. Hoechst 33258 binds in the major groove on the outside of DNA double helices with a binding constant of about 105 M-' (Comings 1975, Miiller & Gautier 1975 while EthDi at low ionic strength mono-intercalates with a binding constant of about 108 M-' i n 0.2 M Na+ (Gaugain et al 197813, Delbarre et al 1983). H33258 binding sites may have been blocked or disrupted by either the stronger binding of EthDi or simply from EthDi intercalation, which is known to elongate DNA (Berman & Young 1981, Waring 1981.…”

Section: Discussionmentioning

confidence: 99%

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An evaluation of fluorescence technigues for measuring DNA and RNA in marine microorganisms

Mordy¹,

Carlson²

1991

Mar. Ecol. Prog. Ser.

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The DNA-specific fluorochrome Hoechst 33258 (H33258) and the DNA-and RNAsensitive fluorochrome ethidium homodlmer (EthDi) were used to detect n g ml-' concentrations of nuclelc acids in marine microorganisms. These fluorochromes were 4 to 5 times more sensitive to DNA than ethidium bromide, and their use significantly reduced the amount of sample necessary to measure nuclelc acids in seawater. Both fluorochromes responded in a linear fashion to standard DNA, but the response of EthDi to RNA was non-linear for the majority of RNA types tested. Chlorophyll a quenched fluorescence of both fluorochromes, especially of EthDi, at concentrations that could be encountered in sample homogenates. Two techniques were used to measure DNA and RNA on cultures of marine bacteria and phytoplankton; H33258 and EthDi together (double fluorochrome technique), and EthDi with and without RNase (RNase digestion method). In general, DNA and RNA were measured equally well using either technique; discrepancies between techniques were attributed to EthDi quenching or the specificity of H33258 for DNA rich in dA-dT base pairs. The double fluorochrome technique was used to determine depth profiles of DNA and RNA/DNA in size-fractionated natural seawater These properties showed significant changes between the surface and 100 m and may be related to changes In biomass or metabolic activity. Although consideration must be given to the RNA standard used and the presence of naturally occuring pigments, the combination of H33258 and EthDi can provide a rapid and sensitive measure of nucleic acids in seawater without the use of nucleases.

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Mechanisms of chromosome banding

Cited by 68 publications

References 11 publications

The Molecular Nature of the Toromere inDrosophila LummeiHackman and its role in Chromosome Behavior

The Molecular Nature of the Toromere inDrosophila LummeiHackman and its role in Chromosome Behavior

Evaluation of acridine orange, LysoTracker Red, and quinacrine as fluorescent probes for long‐term tracking of acidic vesicles

An evaluation of fluorescence technigues for measuring DNA and RNA in marine microorganisms

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