scholarly journals UNDER-REPLICATION OF RIBOSOMAL CISTRONS IN POLYTENE CHROMOSOMES OF RHYNCHOSCIARA

1974 ◽  
Vol 62 (1) ◽  
pp. 215-222 ◽  
Author(s):  
A. G. Gambarini ◽  
F. J. S. Lara
Keyword(s):  
Salivary Gland ◽  
In Situ Hybridization ◽  
Xenopus Laevis ◽  
Related Species ◽  
Polytene Chromosomes ◽  
Chromosome X ◽  
Heterologous Hybridization ◽  
Ribosomal Cistrons ◽  
Rhynchosciara Americana

DNA preparations obtained from several tissues of Rhynchosciara americana and two related species, R. milleri and R. papaveroi, were hybridized to R. americana rRNA. The percentage of hybridization was found to be higher in tissues with low polyteny than in tissues with high polyteny, suggesting a relationship between the amount of rDNA and the tissue polyteny. This could be explained by under-replication of ribosomal cistrons in polytene cells, such as those from the salivary gland. Only slight tissue-dependent changes in the percentages of hybridization can be observed in heterologous hybridization using Xenopus laevis rRNA. The possibility that these experiments could not detect differences in the amount of ribosomal cistrons among tissues is discussed. The female:male ratio for the percentages of hybridization in the salivary gland of R. americana agrees with the results obtained by in situ hybridization experiments (16, 17) which have shown that the rRNA cistrons are distributed among chromosomes other than chromosome X.

The genome of the olive fruit fly Bactrocera oleae: localization of molecular markers by in situ hybridization to the salivary gland polytene chromosomes

Genome ◽  
1999 ◽  
Vol 42 (4) ◽  
pp. 744-751 ◽  
Author(s):  
Anna Zambetaki ◽  
Antigone Zacharopoulou ◽  
Zacharias G. Scouras ◽  
Penelope Mavragani-Tsipidou
Keyword(s):  
Salivary Gland ◽  
Molecular Markers ◽  
In Situ Hybridization ◽  
Polytene Chromosomes ◽  
Fruit Fly ◽  
Bactrocera Oleae ◽  
Olive Fruit Fly ◽  
Olive Fruit

The genome of the Mediterranean fruitflyceratitis capitata: Localization of molecular markers by in situ hybridization to salivary gland polytene chromosomes

Chromosoma ◽  
1992 ◽  
Vol 101 (7) ◽  
pp. 448-455 ◽  
Author(s):  
A. Zacharopoulou ◽  
M. Frisardi ◽  
C. Savakis ◽  
A. S. Robinson ◽  
P. Tolias ◽  
...  
Keyword(s):  
Salivary Gland ◽  
Molecular Markers ◽  
In Situ Hybridization ◽  
Polytene Chromosomes ◽  
The Mediterranean

A molecular cytogenetic comparison between Rhynchosciara americana and Rhynchosciara hollaenderi (Diptera: Sciaridae)

Genome ◽  
1993 ◽  
Vol 36 (5) ◽  
pp. 831-843 ◽  
Author(s):  
Ann Jacob Stocker ◽  
Eduardo Gorab ◽  
J. M. Amabis ◽  
F. J. S. Lara
Keyword(s):  
In Situ Hybridization ◽  
Species Complex ◽  
Polytene Chromosomes ◽  
Chromosomal Evolution ◽  
Molecular Cytogenetic ◽  
The Third ◽  
Dna And Rna ◽  
Rhynchosciara Americana ◽  
Telomeric Heterochromatin

The polytene chromosomes of Rhynchosciara americana and R. hollaenderi, a pair of sibling species in the americana-like group of Rhynchosciara, were compared using a number of techniques, including in situ hybridization. With classical cytological techniques, the only differences observed were in the morphology of centromeric and telomeric heterochromatin, in the size of a DNA and RNA puff, and in the presence of an inversion polymorphism in R. hollaenderi. However, after in situ hybridization with rDNA and poly-r(A) probes, differences between the two species appeared at a number of sites. Differences in poly-r(A) sites were especially informative in establishing phylogenetic relationships between these two species and a third species currently being examined from this group. Chromosomal evolution between these species appears to have occurred mainly through differential amplification and transposition of repetitive sequence DNA, of which dA:dT tracts are an important component. The R. hollaenderi karyotype is tentatively considered more ancestral than that of R. americana because it has features present in the third Rhynchosciara species. Explanations for the monomorphisms observed in Rhynchosciara species and mechanisms of speciation in the group are considered within the context of the species' complex behavior.Key words: Rhynchosciara, chromosome homology, in situ hybridization, phylogeny, evolution.

scholarly journals Effects of Mutations in the Drosophila melanogaster Rif1 Gene on the Replication and Underreplication of Pericentromeric Heterochromatin in Salivary Gland Polytene Chromosomes

Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1501
Author(s):  
Tatyana D. Kolesnikova ◽  
Alexandra V. Kolodyazhnaya ◽  
Galina V. Pokholkova ◽  
Veit Schubert ◽  
Viktoria V. Dovgan ◽  
...  
Keyword(s):  
Salivary Gland ◽  
Satellite Dna ◽  
Polytene Chromosomes ◽  
Replication Timing ◽  
Wild Type ◽  
Chromosome X ◽  
Substantial Fraction ◽  
In The Wild ◽  
Specific Control

In Drosophila salivary gland polytene chromosomes, a substantial portion of heterochromatin is underreplicated. The combination of mutations SuURES and Su(var)3-906 results in the polytenization of a substantial fraction of unique and moderately repeated sequences but has almost no effect on satellite DNA replication. The Rap1 interacting factor 1 (Rif) protein is a conserved regulator of replication timing, and in Drosophila, it affects underreplication in polytene chromosomes. We compared the morphology of pericentromeric regions and labeling patterns of in situ hybridization of heterochromatin-specific DNA probes between wild-type salivary gland polytene chromosomes and the chromosomes of Rif1 mutants and SuUR Su(var)3-906 double mutants. We show that, despite general similarities, heterochromatin zones exist that are polytenized only in the Rif1 mutants, and that there are zones that are under specific control of Su(var)3-9. In the Rif1 mutants, we found additional polytenization of the largest blocks of satellite DNA (in particular, satellite 1.688 of chromosome X and simple satellites in chromosomes X and 4) as well as partial polytenization of chromosome Y. Data on pulsed incorporation of 5-ethynyl-2′-deoxyuridine (EdU) into polytene chromosomes indicated that in the Rif1 mutants, just as in the wild type, most of the heterochromatin becomes replicated during the late S phase. Nevertheless, a significantly increased number of heterochromatin replicons was noted. These results suggest that Rif1 regulates the activation probability of heterochromatic origins in the satellite DNA region.

The genome of the olive fruit fly Bactrocera oleae: localization of molecular markers by in situ hybridization to the salivary gland polytene chromosomes

Genome ◽  
1999 ◽  
Vol 42 (4) ◽  
pp. 744-751 ◽  
Author(s):  
Anna Zambetaki ◽  
Antigone Zacharopoulou ◽  
Zacharias G Scouras ◽  
Penelope Mavragani-Tsipidou
Keyword(s):  
Salivary Gland ◽  
Molecular Markers ◽  
In Situ Hybridization ◽  
Polytene Chromosomes ◽  
Fruit Fly ◽  
Bactrocera Oleae ◽  
Olive Fruit Fly ◽  
Olive Fruit ◽  
Hybridization Mapping

Nine specific DNA probes (genomic or cDNA) from Ceratitis capitata have been mapped by in situ hybridization to the salivary gland polytene chromosomes of the olive fruit fly Bactrocera oleae, a major agricultural pest, thus establishing molecular markers for the 5 autosomal chromosomes. Taking into account the present results, as well as previous data obtained mainly by in situ hybridizations, chromosomal homologies among B. oleae, C. capitata and B. tryoni are established. Data show extensive linkage group conservation among the 3 taxa of the economically important and globally distributed family, the Tephritidae.Key words: Bactrocera oleae, Tephritidae, salivary gland, polytene chromosomes, in situ hybridization, mapping.

scholarly journals Giant Cell Carcinosarcoma of the Parotid Gland With a PLAG 1 Translocation in Association With a Pleomorphic Adenoma With HMGA2 Translocation

2020 ◽  
Vol 154 (6) ◽  
pp. 811-815
Author(s):  
Levon Katsakhyan ◽  
Virginia A LiVolsi ◽  
Ara A Chalian ◽  
Paul J Zhang
Keyword(s):  
Salivary Gland ◽  
In Situ Hybridization ◽  
Parotid Gland ◽  
Giant Cell ◽  
Pleomorphic Adenoma ◽  
De Novo ◽  
Sarcomatous Component ◽  
Gland Tumor ◽  
Parotid Gland Tumor

Abstract Objectives Carcinosarcomas of the salivary gland are rare neoplasms and have been described arising de novo or in association with pleomorphic adenoma (PA). PLAG1 and HMGA2 translocations are known to occur in PAs and carcinomas ex PA but are mutually exclusive. Methods We report a case of a carcinosarcoma in the parotid gland of a 77-year-old man with unusual anaplastic sarcomatoid giant cell morphology. Results Microscopically, a small separate PA was found adjacent to the carcinosarcoma. By conventional notion, the PA and carcinosarcoma would be considered related, as carcinosarcomas are well known to arise from PAs (carcinosarcoma ex PA). However, fluorescence in situ hybridization (FISH) assay demonstrated PLAG1 translocation in the carcinosarcoma and HMGA2 translocation in the separate PA. Conclusions These findings support that the carcinosarcoma likely originated from another PA with a PLAG1 translocation or de novo but not from the coexisting PA harboring a different translocation. To our knowledge, the case is the first to demonstrate PLAG1 translocation by FISH in a sarcomatous component of any parotid gland tumor, which may help better classify these tumors. In addition, multiple PAs are commonly found in the salivary gland, and to our knowledge, our case is the first to demonstrate that the same parotid gland can host PAs and PA-related tumors with different translocations.

Sequential silver staining and in situ hybridization reveal a direct association between rDNA levels and the expression of homologous nucleolar organizing regions: a hypothesis for NOR structure and function

1998 ◽  
Vol 111 (10) ◽  
pp. 1433-1439
Author(s):  
F. Zurita ◽  
R. Jimenez ◽  
M. Burgos ◽  
R.D. de la Guardia
Keyword(s):  
Transcription Factors ◽  
In Situ Hybridization ◽  
Silver Staining ◽  
Organizer Region ◽  
Nucleolar Organizer ◽  
Interindividual Variation ◽  
Nucleolar Organizer Regions ◽  
Single Pair ◽  
Ribosomal Cistrons

We have developed a procedure for sequential silver staining and in situ hybridization to analyze the relationship between the amount of rDNA present in nucleolar organizer regions, as estimated by in situ hybridization, and their level of expression, as estimated by the silver signal. For simplicity we used cells from the insectivorous mole Talpa occidentalis, which have a single pair of nucleolar organizer regions in chromosome pair 3. The relative content of ribosomal cistrons was also related to the hierarchy of activation of the nucleolar organizer regions present in this chromosomal pair. Statistical analyses demonstrated that both the relative level of expression and the activation hierarchy depended mainly on the number of ribosomal cistrons in nucleolar organizer regions. We propose a functional two-step hypothesis, which is consistent with most known data concerning interchromosomal, intercellular and interindividual variation in a number of plant and animal species, including Talpa occidentalis. In step one, the first available transcription factors bind randomly to the ribosomal promoters, such that larger nucleolar organizer regions are more likely to recruit them. In the second step the remaining transcription factors are recruited in a cooperative way, thus completing activation of one nucleolar organizer region, before the next one becomes active.

Detection of rRNA and phaseolin genes on polytene chromosomes of Phaseolus coccineus by fluorescence in situ hybridization after pepsin pretreatment

Genome ◽  
1994 ◽  
Vol 37 (6) ◽  
pp. 1018-1021 ◽  
Author(s):  
M. Nenno ◽  
K. Schumann ◽  
W. Nagl
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Ribosomal Rna ◽  
Storage Protein ◽  
Seed Storage Protein ◽  
Polytene Chromosomes ◽  
Seed Storage ◽  
Phaseolus Coccineus ◽  
Rna Genes

This is the first report of fluorescence in situ hybridization (FISH) on plant polytene chromosomes. Different protease pretreatments have been tested to improve fluorescence in situ hybridization FISH on polytene chromosomes of a plant, Phaseolus coccineus, with the aim to enable the detection of low-copy genes. The structural preservation of the chromosomes and the distinctness of the FISH signals were comparatively analysed with a probe for the ribosomal RNA genes after digestion with pepsin and trypsin. The pepsin pretreatment resulted in a general loosening of chromatin with good conservation of chromosome morphology and an increased number and density of signal points. The six nucleolus organizers exhibited significant differences in condensation. The pretreatment with pepsin enabled the detection of the low-copy genes encoding the seed storage protein phaseolin.Key words: plant, Leguminosae, ribosomal RNA genes, seed storage protein genes, protease.

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