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.

A comparison of polytene chromosomes in salivary glands and orbital bristle trichogen cells in Ceratitis capitata

Genome ◽  
1991 ◽  
Vol 34 (2) ◽  
pp. 215-219 ◽  
Author(s):  
A. Zacharopoulou ◽  
K. Bourtzis ◽  
Ph. Kerremans
Keyword(s):  
Salivary Gland ◽  
Salivary Glands ◽  
Banding Pattern ◽  
Ceratitis Capitata ◽  
Polytene Chromosomes ◽  
Biological Significance ◽  
Fruit Fly ◽  
Banding Patterns ◽  
Homologous Chromosomes ◽  
Different Tissues

The banding patterns of polytene chromosomes in different tissues of the Mediterranean fruit fly, Ceratitis capitata, vary to such an extent that homologous chromosomes cannot be recognised. However, analyses of autosomal breakpoints in several translocation strains allowed chromosomes from the two tissues to be aligned despite their difference in banding pattern. These results were discussed, considering the different hypotheses of the origin and biological significance of polytene chromosome bands.Key words: polytene chromosomes, salivary gland chromosomes, orbital bristle trichogen cell chromosomes, Ceratitis capitata.

Ecdysone-regulated chromosome puffing in the salivary glands of the Mediterranean fruit fly, Ceratitis capitata

Genome ◽  
2001 ◽  
Vol 44 (5) ◽  
pp. 752-762 ◽  
Author(s):  
Angeliki Gariou-Papalexiou ◽  
Anastassios C Mintzas ◽  
Antigone Zacharopoulou
Keyword(s):  
Protein Synthesis ◽  
Salivary Glands ◽  
Ceratitis Capitata ◽  
Polytene Chromosomes ◽  
Fruit Fly ◽  
Protein Synthesis Inhibitor ◽  
Synthesis Inhibitor ◽  
Stage 1

The effect of ecdysone on the puffing activity of the polytene chromosomes of Ceratitis capitata has been studied in organ cultures of late-larval salivary glands. Culture of glands from 120-h-old larvae (puff stage 1) in the presence of ecdysone resulted in the initiation of the late-larval puffing cycle that is normally observed in 145-h-old larvae (puff stage 4). During a 7-h period in the presence of ecdysone, the puffing patterns of most loci resembled the in vivo patterns observed in the period between puff stages 4 and 10, indicating that the first puffing cycle can be initiated by the hormone and proceed almost to completion, in vitro. Culture of salivary glands in the presence of ecdysone and a protein-synthesis inhibitor, as well as ecdysone withdrawal and readdition experiments, indicated that most of the ecdysone-regulated puffs could be categorized into three classes: (i) the puffs that were suppressed immediately by ecdysone, even in the absence of protein synthesis; (ii) the puffs that were induced directly by ecdysone; and (iii) the puffs that were induced indirectly by ecdysone, that is, they were induced after a lag period of a few hours and required protein synthesis for their induction.Key words: polytene chromosomes, puffing patterns, ecdysone, Ceratitis capitata.

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).

Electron Microscope Investigation of PVD Coated Aluminium Alloy Surface Layer

2012 ◽  
Vol 186 ◽  
pp. 192-197 ◽  
Author(s):  
Tomasz Tański ◽  
Krzysztof Labisz
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Surface Layer ◽  
Electron Microscope ◽  
Aluminium Alloy ◽  
Aluminium Alloys ◽  
Wear Resistant ◽  
Electron Microscope Investigation ◽  
Microscope Investigation ◽  
Transmission Electron

The purpose of this work is electron microscope investigation of the Ti/TiCN/TiAlN and Cr/CrN/CrN coatings deposited by PVD process. The investigations were performed using scanning and transmission electron microscopy for the microstructure determination. By mind of the transmission electron microscopy the high resolution and phase determination was possible to obtain. The morphology was studied as well the lattice parameters for the layer matrix and substrate phase identification using diffraction methods was applied. After the coating of the aluminium alloys AlSi9Cu and AlSi9Cu4 with the selected coatings there are crystallites detected with the size of several tenth of diameter. The investigated samples were examined metallographically using electron microscope with different image techniques, also EDS microanalysis and electron diffraction was made. As an implication for the practice a new layer sequence can be possible to develop, based on PVD technique. Some other investigation should be performed in the future, but the knowledge found in this research shows an interesting investigation direction. The originality and value of this combination of TEM investigation for PVD deposited surface lasers on aluminium alloys makes the investigation very attractive for automotive and other industry branches. Some practical implications and employment of the surface treatment technology for elements, made from tool materials, with the PVD and CVD methods, to obtain the high wear resistant coatings, makes it possible to improve the properties of these materials by – among others – decreasing for example their friction coefficient, microhardness increase, improvement of the tribological contact conditions in practical use. One original value is it also to applied the PVD method on a common material like aluminium alloy. The double layer coatings worked out In the PVD process on the Al0Si-Cu alloys substrate hale the following configuration of the layers: bottom layer/gradient layer/wear resistant hard surface layer.

scholarly journals Microwave Processing of Drosophila Tissues for Electron Microscopy

2004 ◽  
Vol 12 (6) ◽  
pp. 42-42 ◽  
Author(s):  
JoAnn Buchanan
Keyword(s):  
Electron Microscopy ◽  
Salivary Glands ◽  
Polytene Chromosomes ◽  
Microwave Processing ◽  
The Body ◽  
Cold Spot ◽  
Large Size ◽  
Body Tissues ◽  
Microwave Effect ◽  
Excellent Preservation

Insect tissue is often difficult to prepare for electron microscopy because of the impenetrable barrier surrounding the body tissues. Drosophila salivary glands have been used for numerous studies because of the large size of the cells and their large polytene chromosomes. Early TEM studies of salivary glands used a protocol that took several days. We were able to achieve excellent preservation and good ultrastructure in Drosophila salivary glands and imaginal discs from Stage L3 larvae using microwave processing in a protocol requiring less than 2 hours.We used a Pelco Laboratory microwave (model #3451) equipped with a Cold Spot, Steadytemp chiller/recirculator run at 15° C, and vacuum chamber (Ted Pella, Mountain Lakes, CA). The heads and attached salivary glands were removed from the animals and placed in PBS. The tissue was transferred to Pelco prep-eze specimen holders (#36157) for ease of handling. Our goal was to use the microwave effect, not the heating effect, to prepare the tissue.

scholarly journals Puffing activity in Drosophila melanogaster Meig. political chromosomes after exposure to microwave radiation

2018 ◽  
Vol 23 ◽  
pp. 393-398
Author(s):  
M. N. Sheyka ◽  
V. Yu. Strashnyuk
Keyword(s):  
Drosophila Melanogaster ◽  
Salivary Glands ◽  
Power Density ◽  
Microwave Radiation ◽  
X Chromosome ◽  
Polytene Chromosomes ◽  
Early Embryogenesis ◽  
Wild Type ◽  
Ocular Micrometer ◽  
Outbred Strain

Aim. The aim of the work was to study the effect of microwave radiation of varying intensity on the polytene chromosomes puffing activity in larvae salivary glands of Drosophila melanogaster. Methods. The wild type outbred strain Oregon-R was used as the material. Microwave radiation with a frequency of 36.64 GHz and a power density of 0.1 and 1 W / m2 was used. Exposure to microwaves was applied in early embryogenesis after 3-hour oviposition. Exposure time was 30 sec. The puff sizes were studied on the squashed preparations of larvae salivary glands stained with acetoorcein. Dimensions of four puffs were investigated^ 2B5-6 (X chromosome); 62E, 71CE and 72CD (chromosome 3L). The measurements were carried out using an ocular-micrometer. Results. There were no significant changes in the size of the puffs in any of the four loci studied, regardless of the applied power density. Conclusions. Microwave radiation in early embryogenesis at a frequency of 36.64 GHz, a power density of 0.1 and 1 W/m2, and an exposure of 30 sec does not have a significant effect on the puff sizes in the Drosophila polytene chromosomes. Keywords: Drosophila melanogaster Meig., giant chromosomes, puff sizes, non-ionizing radiation.

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.

Molecular characterization and chromosomal localization of female-specific genes from the Mediterranean fruit fly Ceratitis capitata (Diptera: Tephritidae)

Genome ◽  
2005 ◽  
Vol 48 (1) ◽  
pp. 139-144 ◽  
Author(s):  
Silvia Ciolfi ◽  
Tiziana de Filippis ◽  
Cristina Torti ◽  
Anna R Malacrida ◽  
Romano Dallai
Keyword(s):  
In Situ Hybridization ◽  
Molecular Characterization ◽  
Ceratitis Capitata ◽  
Polytene Chromosomes ◽  
Fruit Fly ◽  
Accessory Gland ◽  
Mediterranean Fruit Fly ◽  
The Mediterranean ◽  
Female Specific

We report here the molecular characterization of the female-specific FST (female-specific transcript) genes from the Mediterranean fruit fly (medfly) Ceratitis capitata. A genomic clone was isolated, containing a sequence coding for FST. Nucleotide analysis of the clone showed that the gene contains a putative unique intron located in the region encoding the signal peptide. Southern blotting and in situ hybridization analysis on polytene chromosomes suggested the presence of additional genes similar to FST in the genome of the medfly. A novel cDNA clone was isolated from an accessory gland cDNA library, encoding a product that shares 98% identity with the hypothetical translational product of the previously isolated FST cDNA. The novel cDNA was therefore named FST2. The analysis of mitotic and polytene chromosomes by in situ hybridization showed that FST genes map on the left arm of the 4th chromosome of C. capitata.Key words: FST, female-specific genes, C. capitata, medfly, FISH.

Ecdysone-regulated chromosome puffing in the salivary glands of the Mediterranean fruit fly, Ceratitis capitata

Genome ◽  
2001 ◽  
Vol 44 (5) ◽  
pp. 752-762 ◽  
Author(s):  
Angeliki Gariou-Papalexiou ◽  
Anastassios C. Mintzas ◽  
Antigone Zacharopoulou
Keyword(s):  
Salivary Glands ◽  
Ceratitis Capitata ◽  
Fruit Fly ◽  
Mediterranean Fruit Fly ◽  
The Mediterranean

Transmission electron microscope investigation of indentation induced dislocation configurations on the (001) GaSb face

1994 ◽  
Vol 209 (3) ◽  
Author(s):  
J. Doerschel
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Room Temperature ◽  
Stacking Faults ◽  
Electron Microscope Investigation ◽  
Partial Dislocations ◽  
Transmission Electron ◽  
Induced Dislocation

AbstractDislocation configurations induced by room temperature microindentations on the (001) face of GaSb (undoped and Te-doped) have been studied using high voltage transmission electron microscopy. Perfect and partial dislocations could be found in all four arms of the dislocation rosette around the indent. Microtwins and rarely single stacking faults are associated with the partials. Contrary to other binary III–V compounds, an “inverse” glide prism along the [1[unk]0]/[[unk]10] rosette arms is created and it is bounded by {111}

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