Polytene and mitotic chromosome analysis in Ceratitis capitata (Diptera; Tephritidae)

1986 ◽  
Vol 28 (2) ◽  
pp. 180-188 ◽  
Author(s):  
D. G. Bedo
Keyword(s):  
X Chromosome ◽  
Silver Staining ◽  
Mitotic Chromosome ◽  
Ceratitis Capitata ◽  
Fat Body ◽  
Polytene Chromosomes ◽  
Chromosome Analysis ◽  
Mitotic Chromosomes ◽  
Chromosome Separation ◽  
Ectopic Pairing

Polytene chromosomes were found in several larval and pupal tissues of the Medfly, Ceratitis capitata, during a search for chromosomes suitable for detailed cytological analysis. Well-banded highly polytene chromosomes, which could be adequately separated and spread, were found in trichogen cells of the spatulate superior orbital bristles of male pupae. These chromosomes proved suitable for full polytene analysis. Thoracic trichogen cells of both male and female pupae also contain useful polytene chromosomes, although they are considerably thinner and thus more difficult to analyze. Contrasting with those in pupal trichogen cells, the chromosomes in the salivary glands, Malphighian tubules, midgut, hindgut, and fat body of larvae and pupae were difficult to prepare because of high levels of ectopic pairing and chromosome fragmentation. In hindgut preparations partial separation of up to three chromosomes was achieved, but in all other tissues no useful chromosome separation was possible. In trichogen polytene cells, five banded chromosomes and a prominent heterochromatic network associated with a nucleolus are found. The mitotic chromosomes respond to C- and Q-banding and silver staining with considerable variation. This is especially so in the X chromosome, which displays an extensive array of bands following both Q-banding and silver staining. Comparison of Q-banded metaphase and polytene chromosomes demonstrates that the five autosomes are represented by conventional polytene chromosomes, while the sex chromosomes are contained in the heterochromatic net, most of which fluoresces strongly. This suggests that the Q-bands of the mitotic X chromosome are replicated to a greater extent than the nonfluorescent material in polytene cells. This investigation shows C. capitata to have excellent cytological material for both polytene and mitotic analysis.Key words: Ceratitis capitata, Medfly, chromosomes (polytene), banding (chromosome).

Fluorescence banding in mitotic and meiotic chromosomes of the Mediterranean fruit fly, Ceratitis capitata (Diptera: Tephritidae)

Genome ◽  
1989 ◽  
Vol 32 (4) ◽  
pp. 580-588 ◽  
Author(s):  
D. G. Bedo
Keyword(s):  
X Chromosome ◽  
Sex Chromosomes ◽  
Silver Staining ◽  
Ceratitis Capitata ◽  
Fruit Fly ◽  
Mediterranean Fruit Fly ◽  
Mitotic Chromosomes ◽  
C Banding ◽  
Meiotic Chromosomes ◽  
The Mediterranean

Mitotic and meiotic chromosomes of the Mediterranean fruit fly, Ceratitis capitata, were studied using three counterstain-enhanced fluorescence staining methods. The tristaining technique allowed chromomycin A3 (CMA) and distamycin – diamidinophenylindole (DA–DAPI) fluorescence to be observed on the same chromosomes. DAPI–actinomycin D (DAPI–AMD) fluorescence was also carried out. These techniques were complemented with quinacrine staining and C-banding. The results were compared with earlier data on silver staining. The sex chromosomes, particularly the X chromosome, show great banding detail with extensive longitudinal differentiation in mitotic chromosomes. GC- and AT-specific fluorescence is not found in the expected reciprocal pattern at all sites. Comparison with C-banding and silver staining shows that intense fluorescence occurs in lightly C banded regions and silver bands correspond to fluorescent bands rather than nucleolar organizers. The combination of staining data suggests that much of the X chromosome has characteristics intermediate between heterochromatin and euchromatin. Meiotic X chromosomes show much less detail and reduced fluorescence intensity but can still be easily traced throughout meiosis and spermatogenesis.Key words: fluorescence banding, sex chromosomes, Mediterranean fruit fly, Ceratitis capitata.

Mitotic and polytene chromosome analysis in Dacus oleae (Diptera: Tephritidae)

Genome ◽  
1992 ◽  
Vol 35 (3) ◽  
pp. 373-378 ◽  
Author(s):  
P. Mavragani-Tsipidou ◽  
G. Karamanlidou ◽  
A. Zacharopoulou ◽  
S. Koliais ◽  
C. Kastritsis
Keyword(s):  
Olive Oil ◽  
Polytene Chromosome ◽  
Genetic Information ◽  
Cytogenetic Analysis ◽  
Fat Body ◽  
Polytene Chromosomes ◽  
Chromosome Analysis ◽  
Olive Tree ◽  
Mitotic Chromosomes ◽  
Dacus Oleae

The present study constitutes the first attempt to construct a photographic map of the polytene chromosomes of Dacus oleae, a pest of the olive tree that causes serious financial damage in all olive oil producing countries. The map was constructed by using the larval fat body cells, the chromosomes of which are representative of the polytene chromosomes of other polytene tissues. In addition, the mitotic chromosomes of brain ganglia were examined, permitting tentative correlations between mitotic and polytene elements. This investigation shows that D. oleae is suitable for cytogenetic analysis in both mitotic and polytene chromosomes, a fact that may prove very useful for obtaining more detailed genetic information on the pest's natural populations.Key words: Dacus oleae, polytene chromosomes, mitotic chromosomes.

XV.—“Ectopic” Pairing and the Distribution of Heterochromatin in the X-Chromosome of Salivary Gland Nuclei of Drosophila melanogaster

1946 ◽  
Vol 62 (2) ◽  
pp. 114-119 ◽  
Author(s):  
B. M. Slizynski
Keyword(s):  
Drosophila Melanogaster ◽  
Salivary Gland ◽  
Nucleic Acid ◽  
X Chromosome ◽  
Polytene Chromosomes ◽  
Ectopic Pairing

The problem to be presented here emerges from the following groups of facts and more or less generally accepted opinions.As heterochromatin we may define those parts of chromosomes which reach maximum nucleic acid charge in mitosis or meiosis in times other than metaphase. In salivary gland chromosomes (which are more conveniently called polytene chromosomes) of Drosophila melanogaster the proximal heterochromatic parts of all chromosomes come together and form a central undifferentiated mass, the chromocentre. Genetically heterochromatin forms the so-called inert regions of the chromosomes.

Cytogenetic analysis of Malpighian tubule and salivary gland polytene chromosomes of Bactrocera oleae (Dacus oleae) (Diptera: Tephritidae)

Genome ◽  
1995 ◽  
Vol 38 (6) ◽  
pp. 1070-1081 ◽  
Author(s):  
Anna Zambetaki ◽  
Kleanthis Kleanthous ◽  
Penelope Mavragani-Tsipidou
Keyword(s):  
Salivary Gland ◽  
Banding Pattern ◽  
Fat Body ◽  
Polytene Chromosomes ◽  
Malpighian Tubule ◽  
Bactrocera Oleae ◽  
Dacus Oleae ◽  
Somatic Tissues ◽  
Ectopic Pairing ◽  
Tandem Duplications

Photomaps of the Malpighian tubule and the salivary gland polytene chromosomes of Bactrocera oleae (Dacus oleae) are presented and compared with those of the fat body. Five polytene chromosomes (10 polytene arms) corresponding to the five autosomes of the mitotic nuclei, as well as a heterochromatic mass corresponding to the sex chromosomes, are observed in the nuclei of the three somatic tissues. The most prominent features of each polytene chromosome, the reverse tandem duplications, as well as the rather unusual ectopic pairing of the telomeric regions of different chromosome arms, are described. The constancy of the banding pattern based on the analysis of the three larval tissues is discussed.Key words: Bactrocera oleae (Dacus oleae), polytene chromosomes, salivary gland, Malpighian tubule, banding pattern.

Polytene chromosome maps of the melon fly Bactrocera cucurbitae (Diptera: Tephritidae)

Genome ◽  
2002 ◽  
Vol 45 (6) ◽  
pp. 1167-1174 ◽  
Author(s):  
Reza M Shahjahan ◽  
Farzana Yesmin
Keyword(s):  
Salivary Gland ◽  
Polytene Chromosome ◽  
Sex Chromosome ◽  
Polytene Chromosomes ◽  
Chromosome Analysis ◽  
Bactrocera Cucurbitae ◽  
Mitotic Chromosomes ◽  
Larval Brain ◽  
Banding Patterns ◽  
Melon Fly

Standard photographic maps of the polytene chromosomes are presented for the melon fly Bactrocera cucurbitae, a serious pest of fleshy fruits and vegetables. Five larval salivary gland polytene chromosomes (10 polytene arms) were isolated, and their characteristic features and landmarks have been recognized. Banding patterns of each of the polytene arms are presented, where variation in band intensity and puffs appear to reflect fundamental differences in chromosomes. The whole polytene genome has been typically mapped by dividing it into 100 sections and the subsections were lettered. The mitotic chromosomes of larval brain ganglia are also examined, five pairs of autosomes and an XX/XY sex chromosome pair. In addition, a heterochromatic mass corresponding to the sex chromosomes are observed in the polytene nuclei of salivary gland tissue. This investigation showed that B. cucurbitae has excellent cytological material for polytene chromosome analysis and proved to be very useful for obtaining more detailed genetic information on the pest's natural populations.Key words: Bactrocera cucurbitae, salivary gland, banding patterns, polytene maps.

scholarly journals Evaluation of the mutagenic potential of propoxur and methyl parathion using polytene chromosomes of Anopheles stephensi

2012 ◽  
Vol 4 (1) ◽  
pp. 79-84
Author(s):  
Asha Chaudhry ◽  
Preety Bhinder ◽  
Ram Kumar ◽  
Ravneet Kaur
Keyword(s):  
X Chromosome ◽  
Methyl Parathion ◽  
Anopheles Stephensi ◽  
Polytene Chromosomes ◽  
Mutagenic Potential ◽  
X Chromosomes ◽  
Structural Aberrations ◽  
Ectopic Pairing ◽  
Pesticide Genotoxicity

The mutagenicity of two pesticides, propoxur and methyl parathion was evaluated by using polytene chromosomes of Anopheles stephensi. The results were based on the frequency of various structural aberrations encountered in the polytene chromosomes of the larvae treated with LC20 of propoxur and methyl parathion separately. Propoxur induced a total of 67 aberrations as against 15 in the controls while methyl parathion induced 53 aberrations as against 13 in the controls. These aberrations were dominated by inversions, translocations, deletions, ectopic pairing, asynapses, breaks, fusions and induced puffing. The frequency of propoxur induced aberrations was highest in chromosome 3R followed by 2R, 3L, 2L and X-chromosome. Methyl parathion induced highest number of aberrations in 2R followed by 2L, 3R, 3L and X-chromosomes. This study suggests that larval polytene chromosomes are sensitive indicators of pesticide genotoxicity in which both propoxur and methyl parathion are significantly chromotoxic for the genome of a mosquito taken as an experimental insect.

Polytene chromosome mapping in Ceratitis capitata (Diptera: Tephritidae)

Genome ◽  
1987 ◽  
Vol 29 (4) ◽  
pp. 598-611 ◽  
Author(s):  
D. G. Bedo
Keyword(s):  
Salivary Gland ◽  
Polytene Chromosome ◽  
Chromosome Banding ◽  
Mitotic Chromosome ◽  
Ceratitis Capitata ◽  
Polytene Chromosomes ◽  
Chromosome Mapping ◽  
Banding Patterns ◽  
Homologous Chromosomes ◽  
Characteristic Features

Polytene chromosome reference maps of the five autosomes of Ceratitis capitata from male pupal orbital bristle trichogen cells are presented and a correlation is established between two of them and the two largest of the five autosomes in the haploid mitotic complement. Characteristic features of each chromosome are described identifying areas that are difficult to analyze and noting the existence of common alternative band expression. A quantitative analysis of the mitotic karyotype of C. capitata indicates that the two smallest autosome pairs cannot be reliably distinguished. This may present problems with future attempts to establish homologies between the remaining mitotic and polytene chromosomes. A comparison of polytene chromosome banding patterns from salivary gland and trichogen cells failed to find any homologous regions, or even to identify homologous chromosomes. The banding differences are not explained by variation in puffing patterns, heterochromatin expression, or polyteny levels, but appear to reflect fundamental differences in banding patterns of the chromosomes in each tissue. Key words: Ceratitis capitata, polytene chromosome map, mitotic chromosome measurements.

scholarly journals IN SUPPORT OF THE TELOMERE CONCEPT

Genetics ◽  
1975 ◽  
Vol 80 (1) ◽  
pp. 135-142
Author(s):  
Paul A Roberts
Keyword(s):  
Drosophila Melanogaster ◽  
X Chromosome ◽  
Mitotic Chromosome ◽  
Polytene Chromosomes ◽  
Metaphase Chromosomes ◽  
X Chromosomes ◽  
X Ray ◽  
Single Exception

ABSTRACT The frequency of recovered X-ray-induced (4000R) rearrangements that, in all probability, mimic terminal deletions of the X chromosome was only one of, roughly, 105  X chromosomes screened for tip deficiencies. Although the single exception looks terminally deleted, it is probably capped by a very short or nonpolytene telomeric segment. It is apparent from these data that the probability of "healing" or stabilization of a terminally deleted X in the zygotic nucleus or developing embryo of Drosophila melanogaster is vanishingly small. The telomeric caps in two obviously interstitial deficiencies that were recovered represent, roughly, 1/500 of the length of a mitotic chromosome. These findings give some indication of the extreme difficulty of detecting short telomeric segments capping either deleted polytene chromosomes or deleted metaphase chromosomes of, for example, humans.

Electron microscope investigation of polytene chromosomes in the Mediterranean fruit fly Ceratitis capitata

Genome ◽  
1995 ◽  
Vol 38 (4) ◽  
pp. 652-660 ◽  
Author(s):  
V. F. Semeshin ◽  
I. F. Zhimulev ◽  
D. Kritikou ◽  
A. Zacharopoulou
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Salivary Glands ◽  
X Chromosome ◽  
Transcriptional Activity ◽  
Ceratitis Capitata ◽  
Polytene Chromosomes ◽  
Fruit Fly ◽  
Electron Microscope Investigation ◽  
Rnp Granules

Ultrastructural analyses of polytene chromosomes from male pupal orbital bristle cells and from larval salivary glands of Ceratitis capitata were carried out. It was shown that chromatin complexes corresponding to the X chromosome heterochromatic network are surrounded by material containing ribonucleoprotein (RNP) granules 250–300 Å (1 Å = 0.1 nm) in diameter. RNP granules of similar size surround the spherical Y chromosome. These data point out the presence of transcriptional activity in both of these chromosomes. The absence of clear structure in chromosomal regions situated between large bands in both types of tissues was observed. These results support the hypothesis of weak synapsis between chromatids or small chromomeres of polytene chromosomes in this species. In addition, we describe a specific puff revealed in both orbital trichogen cells and salivary glands that is morphologically similar to the 93D puff of Drosophila melanogaster.Key words: Ceratitis capitata, polytene chromosomes, electron microscopy.

scholarly journals Molecular Characterization of hobo-Mediated Inversions in Drosophila melanogaster

Genetics ◽  
1996 ◽  
Vol 144 (2) ◽  
pp. 647-656
Author(s):  
William B Eggleston ◽  
Nac R Rim ◽  
Johng K Lim
Keyword(s):  
X Chromosome ◽  
Polymerase Chain Reaction Amplification ◽  
Polytene Chromosomes ◽  
Chromosomal Inversions ◽  
Hobo Element ◽  
Reaction Amplification ◽  
Notch Locus ◽  
Polymerase Chain

Abstract The structure of chromosomal inversions mediated by hobo transposable elements in the Uc-1 X chromosome was investigated using cytogenetic and molecular methods. Uc-1 contains a phenotypically silent hobo element inserted in an intron of the Notch locus. Cytological screening identified six independent Notch mutations resulting from chromosomal inversions with one breakpoint at cytological position 3C7, the location of Notch. In situ hybridization to salivary gland polytene chromosomes determined that both ends of each inversion contained hobo and Notch sequences. Southern blot analyses showed that both breakpoints in each inversion had hobo-Notch junction fragments indistinguishable in structure from those present in the Uc-1 X chromosome prior to the rearrangements. Polymerase chain reaction amplification of the 12 hobo-Notch junction fragments in the six inversions, followed by DNA sequence analysis, determined that each was identical to one of the two hobo-Notch junctions present in Uc-1. These results are consistent with a model in which hobo-mediated inversions result from homologous pairing and recombination between a pair of hobo elements in reverse orientation.

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