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 ◽  
...  

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.

Genome ◽  
1994 ◽  
Vol 37 (3) ◽  
pp. 477-481 ◽  
Author(s):  
Jie Xu ◽  
R. L. Conner ◽  
A. Laroche

'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.


Genome ◽  
2003 ◽  
Vol 46 (5) ◽  
pp. 893-905 ◽  
Author(s):  
M Kubaláková ◽  
M Valárik ◽  
J Bartoš ◽  
J Vrána ◽  
J Cíhalíková ◽  
...  

Procedures for chromosome analysis and sorting using flow cytometry (flow cytogenetics) were developed for rye (Secale cereale L.). Suspensions of intact chromosomes were prepared by mechanical homogenization of synchronized root tips after mild fixation with formaldehyde. Histograms of relative fluorescence intensity obtained after the analysis of DAPI-stained chromosomes (flow karyotypes) were characterized and the chromosome content of the DNA peaks was determined. Chromosome 1R could be discriminated on a flow karyotype of S. cereale 'Imperial'. The remaining rye chromosomes (2R–7R) could be discriminated and sorted from individual wheat–rye addition lines. The analysis of lines with reconstructed karyotypes demonstrated a possibility of sorting translocation chromosomes. Supernumerary B chromosomes could be sorted from an experimental rye population and from S. cereale 'Adams'. Flow-sorted chromosomes were identified by fluorescence in situ hybridization (FISH) with probes for various DNA repeats. Large numbers of chromosomes of a single type sorted onto microscopic slides facilitated detection of rarely occurring chromosome variants by FISH with specific probes. PCR with chromosome-specific primers confirmed the identity of sorted fractions and indicated suitability of sorted chromosomes for physical mapping. The possibility to sort large numbers of chromosomes opens a way for the construction of large-insert chromosome-specific DNA libraries in rye.Key words: chromosome isolation, chromosome sorting, fluorescence in situ hybridization, repetitive DNA sequences, wheat-rye addition lines, B chromosomes, physical mapping.


2010 ◽  
Vol 58 (3) ◽  
pp. 203-209 ◽  
Author(s):  
É. Szakács ◽  
K. Kruppa ◽  
I. Molnár ◽  
M. Molnár-Láng

The aim of the present study was to test the efficiency of gamma irradiation in inducing translocations between wheat and barley genomes using addition lines. The Martonvásári 9 kr1-Igri disomic addition set, previously produced in Martonvásár, was irradiated with gamma rays. The pattern of irradiation-induced intergenomic chromosome rearrangements was analysed in the mutagenized (M0) generation by genomic in situ hybridization (GISH). Centric fusions and a wide variety of reciprocal, terminal and interstitial translocations were frequently induced. The intergeneric translocations produced here are expected to be stabilized in later backcross progenies as a set of introgression lines carrying few but distinct rearrangements.


1999 ◽  
Vol 77 (3) ◽  
pp. 389-393 ◽  
Author(s):  
Jin-Feng Chen ◽  
Jack E Staub ◽  
Jeffrey W Adelberg ◽  
Jiming Jiang

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.


1994 ◽  
Vol 66 (4) ◽  
pp. 246-249 ◽  
Author(s):  
Y. Matsuda ◽  
K. Moriwaki ◽  
V.M. Chapman ◽  
Y. Hoi-Sen ◽  
J. Akbarzadeh ◽  
...  

Genome ◽  
1997 ◽  
Vol 40 (5) ◽  
pp. 782-784 ◽  
Author(s):  
S. A. Jackson ◽  
J. Jiang ◽  
B. Friebe ◽  
B. S. Gill

The diminutive "midget" chromosome derived from rye (Secale cereale) was analyzed by C-banding and fluorescence in situ hybridization (FISH) using DNA probe pSau3A9 that is located in the centromeres of cereal chromosomes. FISH signals were detected at one end and overlapped one of the two telomeres of the midget, indicating that the midget is a telocentric chromosome. The FISH and C-banding results show that the centromere of the midget chromosome is smaller than those of normal wheat and rye chromosomes. These results indicate that one of the breakpoints occurred in the middle of the centromere of rye chromosome 1R during generation of the midget.Key words: Secale cereale, midget chromosome, centromere, telomere


Genome ◽  
1992 ◽  
Vol 35 (6) ◽  
pp. 1013-1018 ◽  
Author(s):  
I. J. Leitch ◽  
J. S. Heslop-Harrison

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.


Genome ◽  
1996 ◽  
Vol 39 (6) ◽  
pp. 1220-1223 ◽  
Author(s):  
A. Viñas ◽  
C. Gómez ◽  
P. Martínez ◽  
L. Sánchez

A probe containing most of the transcription unit of the major ribosomal genes of Xenopus laevis has been used to localize the rDNA cluster of European eel (Anguilla anguilla) by fluorescence in situ hybridization (FISH). Only one NOR-bearing chromosome pair has been found. The results obtained with this technique confirm the size polymorphism of the NOR revealed previously by other classical cytogenetic techniques. Key words : Anguilla anguilla, rDNA, NOR, FISH, heteromorphism.


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