Physical mapping of the 18S–5.8S–26S rRNA genes in barley by in situ hybridization

Genome ◽  
1992 ◽  
Vol 35 (6) ◽  
pp. 1013-1018 ◽  
Author(s):  
I. J. Leitch ◽  
J. S. Heslop-Harrison
Keyword(s):  
In Situ Hybridization ◽  
Hordeum Vulgare ◽  
Gene Mapping ◽  
Chromosome 1 ◽  
Rrna Genes ◽  
C Banding ◽  
Rdna Sites ◽  
Group 2 ◽  
26S Rrna

The 18S–5.8S–26S rRNA genes have been located on five pairs of barley (Hordeum vulgare L., 2n = 2x = 14) chromosomes (in descending order of copy number, barley chromosome numbers 6, 7, 5, 1, and 2; homoeologous groups 6I, 5I, 1I, 7I, and 2I) by in situ hybridization followed by C-banding. All sites were at intercalary positions. The pairs of major sites on chromosomes 6 (6I)1 and 7 (5I) are well known. Silver staining of nuclei and meiotic analysis have previously indicated that additional rDNA sites may be present, but the presence of sites on a further three chromosome pairs was unexpected. Within the tribe Triticeae, few species have more than two pairs of rDNA sites, and they have not been reported on group 2 chromosomes. We propose calling the new sites Nor-I1 (on chromosome 5 (1I)), Nor-I4 (on chromosome 1 (7I)), and Nor-I5 (on chromosome 2 (2I)), and that any further rDNA sites on homoeologous group 2 chromosomes should be called Nor-5. As conventional, all designations are based on temporal order of discovery in the Triticeae and designating the H. vulgare genome as I. In situ hybridization is valuable for gene mapping, since it can detect the presence of genes with a very wide range of copy numbers at different sites.Key words: C-banding, nucleolus organizer regions, fluorescent in situ hybridization, Hordeum vulgare, gene mapping.

Physical mapping of 45S rRNA genes in Cucumis species by fluorescence in situ hybridization

1999 ◽  
Vol 77 (3) ◽  
pp. 389-393 ◽  
Author(s):  
Jin-Feng Chen ◽  
Jack E Staub ◽  
Jeffrey W Adelberg ◽  
Jiming Jiang
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Cucumis Sativus ◽  
Rrna Genes ◽  
Phylogenetic Distance ◽  
Rdna Sites ◽  
Cucumis Species ◽  
Cucumis Hystrix ◽  
26S Rrna

The chromosomal locations of the genes coding for the 18S-5.8S-26S rRNA was investigated in Cucumis species using fluorescence in situ hybridization. Cucumber (Cucumis sativus L., 2n = 2x = 14) possesses four pairs of rDNA loci that were mapped to chromosomes 1C, 2C, 4C, and 7C. The distinctive hybridization sites of the 18S-5.8S-26S rRNA genes provide several useful cytogenetic markers for identification of chromosomes in C. sativus. The 18S-5.8S-26S rDNA genes have also been detected on two chromosome pairs, one major and one minor pair of loci, in melon (Cucumis melo L., 2n = 2x = 24) and on three pairs of Cucumis hystrix Chakr. chromosomes. The different number and pattern of rDNA sites is consistent with the hypothesis that considerable phylogenetic distance exists among these species.Key words: fluorescence in situ hybridization, 45S rRNA gene, cytogenetics, Cucumis sativus, Cucucmis melo, Cucumis hystrix.

A rapid technique for substituting alien chromosomes into Triticum aestivum and determining their homoeology

1985 ◽  
Vol 27 (5) ◽  
pp. 549-558 ◽  
Author(s):  
Rama S. Kota ◽  
Jan Dvořák
Keyword(s):  
In Situ Hybridization ◽  
Chinese Spring ◽  
Wheat Chromosome ◽  
Rrna Genes ◽  
Gene Probe ◽  
Rapid Technique ◽  
C Banding ◽  
Aegilops Longissima ◽  
26S Rrna

A rapid technique is described for the production of a disomic substitution of an alien chromosome for a selected wheat chromosome directly from the amphiploid. Determination of homoeology between the chromosomes involved is a by-product of this technique. The technique involves the production of a nullisomic amphiploid from a cross between a wheat mono-telosomic and a diploid species and recurrently backcrossing it as a male twice to the monotelosomic. Disomic and ditelosomic substitutions are then selected upon self-pollination. The utility of this technique is shown by producing a large number of disomic and ditelosomic substitutions of an Aegilops longissima chromosome homoeologous to wheat chromosome 6B from two populations of Ae. longissima. The incorporated Ae. longissima chromosome was characterized by C-banding and in situ hybridization of an 18S–26S rRNA gene probe. The chromosome differs in C-band pattern from chromosome 6B of 'Chinese Spring' and does not pair with the 6Bp telosome at metaphase I. It also differs from 'Chinese Spring' chromosome 6B by having the 18S–26S rRNA compound locus in the long arm.Key words: disomic substitution, homoeology, C-banding, in-situ hybridization, rRNA genes, gene synteny, Triticum, Aegilops longissima.

Characterization of Thinopyrum distichum chromosomes using double fluorescence in situ hybridization, RFLP analysis of 5S and 26S rRNA, and C-banding of parents and addition lines

Genome ◽  
1997 ◽  
Vol 40 (5) ◽  
pp. 689-696 ◽  
Author(s):  
A Fominaya ◽  
S. Molnar ◽  
G. Fedak ◽  
K. C. Armstrong ◽  
N.-S. Kim ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Chromosome Pair ◽  
Triticum Turgidum ◽  
5S Rrna ◽  
Polymorphism Analysis ◽  
Addition Lines ◽  
C Banding ◽  
26S Rrna

Diagnostic markers for eight Thinopyrum distichum addition chromosomes in Triticum turgidum were established using C-banding, in situ hybridization, and restriction fragment length polymorphism analysis. The C-band karyotype conclusively identified individual Th. distichum chromosomes and distinguished them from chromosomes of T. turgidum. Also, TaqI and BamHI restriction fragments containing 5S and 18S–5.8S–26S rRNA sequences were identified as positive markers specific to Th. distichum chromosomes. Simultaneous fluorescence in situ hybridization showed both 5S and 18S–5.8S–26S ribosomal RNA genes to be located on chromosome IV. Thinopyrum distichum chromosome VII carried only a 18S–5.8S–26S rRNA locus and chromosome pair II carried only a 5S rRNA locus. The arrangement of these loci on Th. distichum chromosome IV was different from that on wheat chromosome pair 1B. Two other unidentified Th. distichum chromosome pairs also carried 5S rRNA loci. The homoeologous relationship between Th. distichum chromosomes IV and VII and chromosomes of other members of the Triticeae was discussed by comparing results obtained using these physical and molecular markers.Key words: Triticum turgidum, homoeologous relationship, Triticeae, addition lines, NOR.

Chromatin characterization by banding techniques, in situ hybridization, and nuclear DNA content in Cicer L. (Leguminosae)

Genome ◽  
1996 ◽  
Vol 39 (2) ◽  
pp. 258-265 ◽  
Author(s):  
I. Galasso ◽  
D. Pignone ◽  
M. Frediani ◽  
M. Maggiani ◽  
R. Cremonini
Keyword(s):  
In Situ Hybridization ◽  
Dna Content ◽  
Nuclear Dna ◽  
Hybrid Sterility ◽  
Nuclear Dna Content ◽  
5S Rdna ◽  
Rrna Genes ◽  
Evolutionary Pathway ◽  
C Banding

The karyotypes of three accessions, one each from three annual species of the genus Cicer, namely Cicer arietinum, Cicer reticulation, and Cicer echinospermum, were examined and compared using C-banding, the fluorochromes chromomycin A3, DAPI, and Hoechst 33258, in situ hybridization of the 18S–5.8S–25S and 5S rDNA sequences, and silver staining. The nuclear DNA content of the three species and the amount of heterochromatin were also determined. The results suggest an evolutionary pathway in which C. reticulatum is the ancestral species from which both C. arietinum and C. echinospermum are derived with the loss of one pair of satellites; subsequently, C. echinospermum further differentiated by the accumulation of chromosomal rearrangement(s) that gave rise to a hybrid sterility barrier. Key words : Cicer, C-banding, fluorochromes, Ag staining, rRNA genes.

Physical mapping of four sites of 5S rDNA sequences and one site of the α-amylase-2 gene in barley (Hordeum vulgare)

Genome ◽  
1993 ◽  
Vol 36 (3) ◽  
pp. 517-523 ◽  
Author(s):  
I. J. Leitch ◽  
J. S. Heslop-Harrison
Keyword(s):  
In Situ Hybridization ◽  
Hordeum Vulgare ◽  
Physical Mapping ◽  
5S Rdna ◽  
Chromosome 1 ◽  
Chromosome 2 ◽  
Hordeum Vulgare L ◽  
Rdna Sequences ◽  
5S Rdna Sequence

The 5S rDNA sequences have been mapped on four pairs of barley (Hordeum vulgare L.) chromosomes using in situ hybridization and barley monotelotrisomic lines. The 5S rDNA sequences are located, genetically and physically, on the short arm of chromosome 1 (7I) and the long arms of chromosomes 2 (2I) and 3 (3I). The 5S rDNA sequence is also located on the physically long arm of chromosome 4 (4I). Only one site on chromosome 2(2I) has previously been reported. The characteristic locations of the 5S rDNA sequences make them useful as molecular markers to identify each barley chromosome. The physical position of the low-copy α-amylase-2 gene was determined using in situ hybridization; the location of this gene on the long arm of chromosome 1 (7I) was confirmed by reprobing the same preparation with the 5S rDNA probe. The results show that there is a discrepancy between the physical and genetic position of the α-amylase-2 gene.Key words: genetic mapping, physical mapping, barley, mapping, 5S DNA, α-amylase, in situ hybridization.

Physical mapping of ribosomal DNA sites in Festuca arundinacea and related species by in situ hybridization

Genome ◽  
1997 ◽  
Vol 40 (3) ◽  
pp. 406-410 ◽  
Author(s):  
H. M. Thomas ◽  
J. A. Harper ◽  
M. R. Meredith ◽  
W. G. Morgan ◽  
I. P. King
Keyword(s):  
In Situ Hybridization ◽  
Ribosomal Dna ◽  
Physical Mapping ◽  
Festuca Arundinacea ◽  
Rrna Genes ◽  
Structural Rearrangements ◽  
Phylogenetic Studies ◽  
Rdna Sites ◽  
5S Rrna Genes

The positions of the 18S–5.8S–26S and 5S rRNA genes have been physically mapped on the chromosomes of diploid, tetraploid, and hexaploid Festuca species by in situ hybridization. The number and position of the rDNA sites in the species were compared. The results confirm some of the earlier phylogenetic studies of these species but suggest that some structural rearrangements have occurred and that sites have been lost during polyploidization. Keywords: Festuca, in situ hybridization, phylogeny, physical mapping, rDNA.

Organization of the 5S ribosomal RNA genes in the genome of tomato

Genome ◽  
1991 ◽  
Vol 34 (4) ◽  
pp. 509-514 ◽  
Author(s):  
Nora L. V. Lapitan ◽  
Martin W. Ganal ◽  
Steven D. Tanksley
Keyword(s):  
In Situ Hybridization ◽  
Ribosomal Rna ◽  
Gel Electrophoresis ◽  
Pulsed Field Gel Electrophoresis ◽  
5S Rrna ◽  
Chromosome 1 ◽  
Rrna Genes ◽  
5S Rrna Genes

The 5S ribosomal RNA (rRNA) genes represent one of the most abundant gene families in eukaryotic genomes and have been a model system for the study of molecular organization and evolution of multigene families in eukaryotes. This paper reports a detailed characterization of the 5S rRNA genes of tomato (Lycopersicon esculentum) with respect to chromosome assignment, chromosomal localization, copy number, and physical size. By restriction fragment length polymorphism, the tandemly repeated 5S rRNA genes were assigned to a region of chromosome 1 of tomato. These results were confirmed by in situ hybridization onto tomato metaphase chromosomes. The single hybridization signal was localized to the short arm of chromosome 1, in a region close to the centromere. Based on reconstruction experiments, it was estimated that the 400-bp repeating unit occurs in approximately 1000 copies per haploid genome. Physical characterization of the entire locus was then performed by means of pulsed-field gel electrophoresis. Digestion of high molecular weight DNA of tomato with restriction enzymes such as PvuII, ClaI, and BglII resulted in a very prominent band with a size between approximately 450 and 600 kb. This value closely matched the estimated size of the gene cluster based on reconstruction experiments. The data therefore suggest that all the 5S rRNA genes in tomato occur in a single, continuous array, uninterrupted by unrelated sequences.Key words: 5S rRNA genes, organization, Lycopersicon esculentum, in situ hybridization, pulsed-field gel electrophoresis.

A high-resolution karyotype of cucumber (Cucumis sativus L. 'Winter Long') revealed by C-banding, pachytene analysis, and RAPD-aided fluorescence in situ hybridization

Genome ◽  
2005 ◽  
Vol 48 (3) ◽  
pp. 534-540 ◽  
Author(s):  
Dal-Hoe Koo ◽  
Hae-Woon Choi ◽  
Jeongki Cho ◽  
Yoonkang Hur ◽  
Jae-Wook Bang
Keyword(s):  
In Situ Hybridization ◽  
High Resolution ◽  
Fluorescence In Situ Hybridization ◽  
Cucumis Sativus ◽  
Rapd Marker ◽  
Chromosome 1 ◽  
Molecular Karyotyping ◽  
Cucumis Sativus L ◽  
C Banding

Using molecular cytogenetic DNA markers, C-banding, pachytene analysis, and fluorescence in situ hybridization (FISH), a high-resolution karyotype was established in the cucumber. C-banding showed distinct hetero chro matic bands on the pericentromeric, telomeric, and intercalary regions of the chromosomes. The C-banding patterns were also consistent with the morphology of 4'-6-diamino-2-phenylindole dihydrochloride (DAPI)-stained pachytene chro mosomes. Two repetitive DNA fragments, CsRP1 and CsRP2, were obtained by PCR and localized on the mitotic metaphase and meiotic pachytene chromosomes. CsRP1 was detected on the pericentromeric heterochromatic regions of all chromosomes, except chromosome 1. CsRP2 was detected on 5 (chromosomes 1, 2, 3, 4, and 7) of 7 chromosomes. All homologous chromosome pairs could be distinguished by FISH using 2 RAPD markers. This is the first report on molecular karyotyping of mitotic and meiotic spreads of cucumber.Key words: Cucumis sativus, C-banding, FISH, karyotype, pachytene, RAPD marker, rDNA.

C-banding and fluorescence in situ hybridization studies of the wheat–alien hybrid 'Agrotana'

Genome ◽  
1994 ◽  
Vol 37 (3) ◽  
pp. 477-481 ◽  
Author(s):  
Jie Xu ◽  
R. L. Conner ◽  
A. Laroche
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Genomic Dna ◽  
Chromosome Engineering ◽  
C Banding ◽  
Chinese Spring Wheat ◽  
Mother Cells ◽  
Alien Chromatin ◽  
Chromosome Segments

'Agrotana', a wheat-alien hybrid (2n = 56), is a potential source of resistance to common root rot, stem rust, wheat streak mosaic virus, and the wheat curl mite. However, the origin of 'Agrotana', reported to be durum wheat × Agropyron trichophorum (pubescent wheatgrass), is uncertain. The objective of this investigation was to determine the chromosome constitution of 'Agrotana' using C-banding and fluorescence in situ hybridization techniques. The F1 hybrid of 'Agrotana' × 'Chinese Spring' wheat showed 7 I + 21 II in 14.9% of the pollen mother cells, evidence of the presence of the A, B, and D genomes in 'Agrotana'. The hybrid had 16 heavily C-banded chromosomes, namely 4A, and 1-7B of wheat, and a translocation that probably involved wheat chromosomes 2A and 2D. In situ hybridization using biotinylated genomic DNA of Ag. trichophorum cv. Greenleaf blocked with CS DNA failed to identify the alien chromosomes in 'Agrotana', indicating that the alien chromosomes were not likely derived from pubescent wheatgrass. In situ hybridization using labelled wheat genomic DNA blocked with 'Agrotana' DNA revealed that 'Agrotana' had 40 wheat, 14 alien, and 2 (a pair) wheat–alien translocated chromosomes. There was no homology between wheat and the alien chromosomes or chromosome segments involved in the wheat–alien recombinant. Two of the seven pairs of alien chromosomes were homoeologous to each other. The ability to identify alien chromatin in wheat using labelled wheat DNA instead of labelled alien DNA will be particularly useful in chromosome engineering of wheat germplasms having alien chromatin of unknown origin.Key words: wheat–alien hybrid, C-banding, fluorescence in situ hybridization, labelled wheat DNA as probe.

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