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

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.

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.


Cytometry ◽  
1994 ◽  
Vol 15 (3) ◽  
pp. 193-198 ◽  
Author(s):  
Timothy W. Houseal ◽  
William R. Dackowski ◽  
Gregory M. Landes ◽  
Katherine W. Klinger

Reproduction ◽  
2003 ◽  
pp. 317-325 ◽  
Author(s):  
I Parrilla ◽  
JM Vazquez ◽  
M Oliver-Bonet ◽  
J Navarro ◽  
J Yelamos ◽  
...  

Successful evaluation of X- and Y-chromosome-bearing sperm separation technology using flow cytometry-cell sorter is of great importance. Fluorescence in situ hybridization (FISH), which allows for the detection of specific nucleic acid sequences on morphologically preserved spermatozoa, is an ideal method for quantitatively and qualitatively assessing the purity of sorted sperm samples. In this study specific pig DNA direct probes for small regions of chromosomes 1 and Y were used. Chromosome 1 was labelled in green and used as internal control to detect a lack of hybridization, whereas chromosome Y was labelled in red. Nick translation was used as the labelling method for the preparation of these probes. Spermatozoa, unsorted and sorted for high and low Y-chromosome purity from ejaculates of five boars, were fixed on slides and two-colour direct FISH was performed for chromosomes 1 and Y. About 500 non-sorted and 200 sorted spermatozoa per sample were scored. The proportion of Y-chromosome-bearing spermatozoa was determined by the presence of a red fluorescent signal on the sperm head and the proportion of X-chromosome-bearing spermatozoa was determined by subtraction. The efficiency of the hybridization procedure was established as near 98% on sorted and unsorted samples. The results of this study confirm that direct FISH using specific pig DNA probes labelled by nick translation provides a useful tool for laboratory validation of sperm separation by flow sorting technology. Moreover, the ease of nick translation and the quality of the fluorescent signal obtained using this method makes this procedure the most appropriate method for labelling pig DNA probes to be used for direct FISH on pig spermatozoa.


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.


1996 ◽  
Vol 44 (5) ◽  
pp. 525-529 ◽  
Author(s):  
J Wiegant ◽  
N Verwoerd ◽  
S Mascheretti ◽  
M Bolk ◽  
H J Tanke ◽  
...  

Synthesis of fluorochrome-modified deoxyribonucleotides has been carried out mostly by linking the fluorochrome molecule to the C-5 position of dUTP via an allylamine spacer, similar to the modification of allylamine-dUTP with the haptens biotin and digoxigenin. Recently, a new series of fluorescent nucleotides has been prepared by using an alkynyl bridge between the uracil moiety and the fluorochrome. Here we report the qualitative and quantitative analysis of fluorescence in situ hybridization results obtained on interphase cells and chromosomes with a variety of highly repetitive and single-copy DNA probes that were modified by nick translation with such alkynyl dUTPs. A qualitative comparison was made of the alkynyl dUTPs conjugated to the fluorochromes fluorescein, the cyanine dye Cy3, tetramethylrhodamine, Lissamine and Texas Red. With the exception of tetramethylrhodamine, all fluorochromes performed satisfactorily. The cyanine dye Cy3 provided the highest sensitivity, i.e., cosmid and YAC probes could easily be visualized by conventional fluorescence microscopy. In a quantitative assay, different nick translation conditions were tested using a human chromosome 1 satellite III probe (pUC1.77) and alkynyl dUTPs labeled with fluorescein and Cy3. Using these two nucleotides, FISH signal intensities on interphase nuclei from human lymphocytes were quantitated by digital imaging microscopy. The strongest signals were obtained when during nick translation the ratio between dTTP and fluorescein-dUTP or Cy3-dUTP was 1:5.


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