scholarly journals The Drosophila salivary gland chromocenter contains highly polytenized subdomains of mitotic heterochromatin.

Genetics ◽  
1995 ◽  
Vol 139 (2) ◽  
pp. 659-670 ◽  
Author(s):  
P Zhang ◽  
A C Spradling
Keyword(s):  
Salivary Gland ◽  
Dna Sequences ◽  
Polytene Chromosomes ◽  
Centromeric Heterochromatin ◽  
Mitotic Chromosomes ◽  
Satellite Dnas ◽  
Central Mass ◽  
P Elements

Abstract Peri-centromeric regions of Drosophila melanogaster chromosomes appear heterochromatic in mitotic cells and become greatly underrepresented in giant polytene chromosomes, where they aggregate into a central mass called the chromocenter. We used P elements inserted at sites dispersed throughout much of the mitotic heterochromatin to analyze the fate of 31 individual sites during polytenization. Analysis of DNA sequences flanking many of these elements revealed that middle repetitive or unique sequence DNAs frequently are interspersed with satellite DNAs in mitotic heterochromatin. All nine Y chromosome sites tested were underrepresented > 20-fold on Southern blots of polytene DNA and were rarely or never detected by in situ hybridization to salivary gland chromosomes. In contrast, nine tested insertions in autosomal centromeric heterochromatin were represented fully in salivary gland DNA, despite the fact that at least six were located proximal to known blocks of satellite DNA. The inserted sequences formed diverse, site-specific morphologies in the chromocenter of salivary gland chromosomes, suggesting that domains dispersed at multiple sites in the centromeric heterochromatin of mitotic chromosomes contribute to polytene beta-heterochromatin. We suggest that regions containing heterochromatic genes are organized into dispersed chromatin configurations that are important for their function in vivo.

scholarly journals Triple-Helical DNA in Drosophila Heterochromatin

Cells ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 227 ◽  
Author(s):  
Eduardo Gorab
Keyword(s):  
Nucleic Acids ◽  
Dna Sequences ◽  
Detection Methods ◽  
Triplex Dna ◽  
Thiazole Orange ◽  
Chromosomal Dna ◽  
Mitotic Chromosomes ◽  
Satellite Repeats

Polynucleotide chains obeying Watson-Crick pairing are apt to form non-canonical complexes such as triple-helical nucleic acids. From early characterization in vitro, their occurrence in vivo has been strengthened by increasing evidence, although most remain circumstantial particularly for triplex DNA. Here, different approaches were employed to specify triple-stranded DNA sequences in the Drosophila melanogaster chromosomes. Antibodies to triplex nucleic acids, previously characterized, bind to centromeric regions of mitotic chromosomes and also to the polytene section 59E of mutant strains carrying the brown dominant allele, indicating that AAGAG tandem satellite repeats are triplex-forming sequences. The satellite probe hybridized to AAGAG-containing regions omitting chromosomal DNA denaturation, as expected, for the intra-molecular triplex DNA formation model in which single-stranded DNA coexists with triplexes. In addition, Thiazole Orange, previously described as capable of reproducing results obtained by antibodies to triple-helical DNA, binds to AAGAG repeats in situ thus validating both detection methods. Unusual phenotype and nuclear structure exhibited by Drosophila correlate with the non-canonical conformation of tandem satellite arrays. From the approaches that lead to the identification of triple-helical DNA in chromosomes, facilities particularly provided by Thiazole Orange use may broaden the investigation on the occurrence of triplex DNA in eukaryotic genomes.

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

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 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

The molecular structure, chromosomal organization, and interspecies distribution of a family of tandemly repeated DNA sequences of Antirrhinum majus L.

Genome ◽  
1996 ◽  
Vol 39 (2) ◽  
pp. 243-248 ◽  
Author(s):  
Thomas Schmidt ◽  
Jörg Kudla
Keyword(s):  
In Situ Hybridization ◽  
Dna Sequences ◽  
Satellite Dna ◽  
Antirrhinum Majus ◽  
Repeated Dna ◽  
Satellite Dnas ◽  
Repeated Dna Sequences ◽  
The North ◽  
Tandemly Repeated Dna

Monomers of a major family of tandemly repeated DNA sequences of Antirrhinum majus have been cloned and characterized. The repeats are 163–167 bp long, contain on average 60% A + T residues, and are organized in head-to-tail orientation. According to site-specific methylation differences two subsets of repeating units can be distinguished. Fluorescent in situ hybridization revealed that the repeats are localized at centromeric regions of six of the eight chromosome pairs of A. majus with substantial differences in array size. The monomeric unit shows no homologies to other plant satellite DNAs. The repeat exists in a similar copy number and conserved size in the genomes of six European species of the genus Antirrhinum. Tandemly repeated DNA sequences with homology to the cloned monomer were also found in the North American section Saerorhinum, indicating that this satellite DNA might be of ancient origin and was probably already present in the ancestral genome of both sections. Key words : Antirrhinum majus, satellite DNA, repetitive DNA, methylation, in situ hybridization.

scholarly journals Genomic in situ hybridization in interspecific hybrids of scallops (Bivalvia, Pectinidae) and localization of the satellite DNA Cf303, and the vertebrate telomeric sequences (TTAGGG)n on chromosomes of scallop Chlamys farreri (Jones & Preston, 1904)

2018 ◽  
Vol 12 (1) ◽  
pp. 83-95
Author(s):  
Liping Hu ◽  
Liming Jiang ◽  
Ke Bi ◽  
Huan Liao ◽  
Zujing Yang ◽  
...  
Keyword(s):  
Interspecific Hybrids ◽  
Distribution Patterns ◽  
Mitotic Chromosomes ◽  
Chromosomal Distribution ◽  
Satellite Dnas ◽  
Banding Patterns ◽  
Telomeric Sequences ◽  
Specific Distribution ◽  
Species Specific

Mitotic chromosome preparations of the interspecific hybrids Chlamysfarreri (Jones & Preston, 1904) × Patinopectenyessoensis (Jay, 1857), C.farreri × Argopectenirradinas (Lamarck, 1819) and C.farreri × Mimachlamysnobilis (Reeve, 1852) were used to compare two different scallop genomes in a single slide. Although genomic in situ hybridization (GISH) using genomic DNA from each scallop species as probe painted mitotic chromosomes of the interspecific hybrids, the painting results were not uniform; instead it showed species-specific distribution patterns of fluorescent signals among the chromosomes. The most prominent GISH-bands were mainly located at centromeric or telomeric regions of scallop chromosomes. In order to illustrate the sequence constitution of the GISH-bands, the satellite Cf303 sequences of C.farreri and the vertebrate telomeric (TTAGGG)n sequences were used to map mitotic chromosomes of C.farreri by fluorescence in situ hybridization (FISH). The results indicated that the GISH-banding pattern presented by the chromosomes of C.farreri is mainly due to the distribution of the satellite Cf303 DNA, therefore suggesting that the GISH-banding patterns found in the other three scallops could also be the result of the chromosomal distribution of other species-specific satellite DNAs.

Nonrandom distribution of long mono- and dinucleotide repeats in Drosophila chromosomes: correlations with dosage compensation, heterochromatin, and recombination

1989 ◽  
Vol 9 (3) ◽  
pp. 1173-1182
Author(s):  
K Lowenhaupt ◽  
A Rich ◽  
M L Pardue
Keyword(s):  
Y Chromosome ◽  
Dna Sequences ◽  
Polytene Chromosomes ◽  
Drosophila Species ◽  
Repeated Dna ◽  
Dinucleotide Repeats ◽  
Order Of Magnitude ◽  
The Individual ◽  
And Function

Long stretches of (dC-dA)n.(dT-dG)n, abbreviated CA/TG, have a distinctive distribution on Drosophila chromosomes (M.L. Pardue, K. Lowenhaupt, A. Rich, and A. Nordheim, EMBO J. 6:1781-1789, 1987). The distribution of CA/TG suggests a correlation with the overall transcriptional activity of chromosomal regions and with the ability to undergo meiotic recombination. These correlations are conserved among Drosophila species and may indicate one or more chromosomal functions. To test the generality of these findings, we analyzed the distribution of the rest of the six possible mono- and dinucleotide repeats (A/T, C/G, AT/AT, CA/TG, CT/AG, and CG/CG). All but CG/CG were present at significant levels in the genomes of the six Drosophila species studied; however, A/T levels were an order of magnitude lower than those of the other sequences. Data base analyses suggested that the same sequences are present in other eucaryotes. Like CA/TG, both CT/AG and C/G showed increased levels on dosage-compensating chromosomes; however, the individual sites clearly differed for each sequence. In contrast, A/T and AT/AT, although present in Drosophila DNA, could not be detected in situ in polytene chromosomes. We also used in situ hybridization to analyze the neo-Y chromosome of Drosophila miranda, an ancestral autosome that has become attached to the Y chromosome and is now partially heterochromatic. The neo-Y has acquired repeated DNA sequences; we found that the added sequences are as devoid of mono- and dinucleotide repeats as other heterochromatin. The distribution and function of these sequences are likely to result from both their repetitious nature and base contents.

scholarly journals Prins and C-PRINS: Promising tools for the physical mapping of the lupin genome

2007 ◽  
Vol 12 (1) ◽  
Author(s):  
Anna Kaczmarek ◽  
Barbara Naganowska ◽  
Bogdan Wolko
Keyword(s):  
Vicia Faba ◽  
Physical Mapping ◽  
Dna Sequences ◽  
Molecular Cytogenetics ◽  
Chromosome Identification ◽  
Prins Reaction ◽  
Mitotic Chromosomes ◽  
Coding Sequences ◽  
Dna Labeling

AbstractTwo molecular cytogenetics methods, PRINS (primed in situ DNA labeling) and C-PRINS (cycling PRINS), were optimized for the physical mapping of several types of DNA sequences on the mitotic chromosomes of the narrow-leafed lupin (Lupinus angustifolius L.). The fragment of the FokI element from Vicia faba was localised by indirect PRINS reaction. Two other sequences, fragments of the coding sequences of L. luteus and of L. angustifolius, were localised by indirect C-PRINS. These techniques are faster and more sensitive than FISH, and they allowed the mapping of short DNA fragments. The data obtained shows that both types of PRINS are valuable tools for chromosome identification in lupin.

Chromosome evolution in wild oat grasses (Aveneae) revealed by molecular phylogeny

Genome ◽  
2009 ◽  
Vol 52 (4) ◽  
pp. 361-380 ◽  
Author(s):  
Grit Winterfeld ◽  
Elke Döring ◽  
Martin Röser
Keyword(s):  
Molecular Phylogeny ◽  
Dna Sequences ◽  
Chromosome Evolution ◽  
5S Rdna ◽  
Fluorochrome Staining ◽  
Satellite Dnas ◽  
A Genome ◽  
Satellite Chromosomes ◽  
Species Specific

Karyotype structures revealed by in situ hybridization with ribosomal and satellite DNAs and fluorochrome staining of AT- or GC-rich regions are reported for 23 diploid to tetraploid taxa of Aveneae genera Arrhenatherum , Avena , Helictotrichon , and Pseudarrhenatherum . Chromosomal features are compared with a molecular phylogeny generated on nuclear ribosomal (ITS, 5S) and chloroplast (matK) DNA sequences. Ancestral chromosomal character states are (1) two satellite chromosomes per set of x = 7, (2) 5S rDNA localized in nonsatellite chromosomes, (3) large chromosomes with (4) rather equal lengths of their respective chromosome arms, (5) sets with strong variance of chromosome lengths, (6) absence or small amounts of heterochromatin, and (7) absence or no detectable amplification of the satellite DNAs tested. Overall, most karyotype characteristics are species specific, but common patterns were found for the species of two large subgenera of Helictotrichon. Pseudarrhenatherum, although nested in the molecular phylogeny within Helictotrichon subgenus Helictotrichon, deviates strongly in karyotype characters such as Arrhenatherum as sister of Avena. The karyotype of Helictotrichon jahandiezii , sister to the clade of Helictotrichon subgenera Helictotrichon, Avena, and Arrhenatherum, strongly resembles that of Avena macrostachya . Karyotype features suggest that perennial A. macrostachya and H. jahandiezii are close to the C-genome species of annual Avena, whereas the Avena A genome resembles that of Arrhenatherum.

Sign in / Sign up

Export Citation Format

Share Document