Distribution of highly repeated DNA sequences in species of the genus Lens Miller

Genome ◽  
2003 ◽  
Vol 46 (6) ◽  
pp. 1118-1124 ◽  
Author(s):  
Incoronata Galasso

Multiple-target fluorescence in situ hybridization (FISH) was applied on mitotic chromosomes of seven Lens taxa using two highly repetitive sequences (pLc30 and pLc7) isolated from the cultivated lentil and the multigene families for the 18S–5.8S–25S (pTa71) and 5S rRNA (pTa794) from wheat simultaneously as probes. The number and location of pLc30 and pLc7 sites on chromosomes varied markedly among the species, whereas the hybridization pattern of 5S rDNA and 18S–5.8S–25S rDNA was less variable. In general, each species showed a typical FISH karyotype and few differences were observed among accessions belonging to the same species, except for the accessions of Lens odemensis. The most similar FISH karyotype to the cultivated lentil is that of Lens culinaris subsp. orientalis, whereas Lens nigricans and Lens tomentosus are the two species that showed the most divergent FISH patterns compared with all taxa for number and location of pLc30 and 18S–5.8S–25S rDNA sites.Key words: chromosome identification, comparative FISH karyotype, wild Lens species, genomic relationships.

Genome ◽  
2011 ◽  
Vol 54 (9) ◽  
pp. 710-717 ◽  
Author(s):  
B. Kolano ◽  
B.W. Gardunia ◽  
M. Michalska ◽  
A. Bonifacio ◽  
D. Fairbanks ◽  
...  

The chromosomal organization of two novel repetitive DNA sequences isolated from the Chenopodium quinoa Willd. genome was analyzed across the genomes of selected Chenopodium species. Fluorescence in situ hybridization (FISH) analysis with the repetitive DNA clone 18–24J in the closely related allotetraploids C. quinoa and Chenopodium berlandieri Moq. (2n = 4x = 36) evidenced hybridization signals that were mainly present on 18 chromosomes; however, in the allohexaploid Chenopodium album L. (2n = 6x = 54), cross-hybridization was observed on all of the chromosomes. In situ hybridization with rRNA gene probes indicated that during the evolution of polyploidy, the chenopods lost some of their rDNA loci. Reprobing with rDNA indicated that in the subgenome labeled with 18–24J, one 35S rRNA locus and at least half of the 5S rDNA loci were present. A second analyzed sequence, 12–13P, localized exclusively in pericentromeric regions of each chromosome of C. quinoa and related species. The intensity of the FISH signals differed considerably among chromosomes. The pattern observed on C. quinoa chromosomes after FISH with 12–13P was very similar to GISH results, suggesting that the 12–13P sequence constitutes a major part of the repetitive DNA of C. quinoa.


Author(s):  
Anna Kaczmarek ◽  
Barbara Naganowska ◽  
Bogdan Wolko

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.


2015 ◽  
Vol 147 (2-3) ◽  
pp. 161-168 ◽  
Author(s):  
Natalia D.M. Carvalho ◽  
Vanessa S.S. Pinheiro ◽  
Edson J. Carmo ◽  
Leonardo G. Goll ◽  
Carlos H. Schneider ◽  
...  

Repetitive DNA is the largest fraction of the eukaryote genome and comprises tandem and dispersed sequences. It presents variations in relation to its composition, number of copies, distribution, dynamics, and genome organization, and participates in the evolutionary diversification of different vertebrate species. Repetitive sequences are usually located in the heterochromatin of centromeric and telomeric regions of chromosomes, contributing to chromosomal structures. Therefore, the aim of this study was to physically map repetitive DNA sequences (5S rDNA, telomeric sequences, tropomyosin gene 1, and retroelements Rex1 and SINE) of mitotic chromosomes of Amazonian species of teiids (Ameiva ameiva, Cnemidophorus sp. 1, Kentropyx calcarata, Kentropyx pelviceps, and Tupinambis teguixin) to understand their genome organization and karyotype evolution. The mapping of repetitive sequences revealed a distinct pattern in Cnemidophorus sp. 1, whereas the other species showed all sequences interspersed in the heterochromatic region. Physical mapping of the tropomyosin 1 gene was performed for the first time in lizards and showed that in addition to being functional, this gene has a structural function similar to the mapped repetitive elements as it is located preferentially in centromeric regions and termini of chromosomes.


Genome ◽  
2005 ◽  
Vol 48 (1) ◽  
pp. 145-153 ◽  
Author(s):  
Hieronim Golczyk ◽  
Robert Hasterok ◽  
Andrzej J Joachimiak

Fluorescence in situ hybridization (FISH) using 25S rDNA, 5S rDNA, and telomere sequences as probes was carried out in the complex permanent heterozygote Rhoeo spathacea. Telomere sites were exclusively terminal. All 10 25S rDNA loci were located distally and appeared transcriptionally active after silver staining. Six distal and 2 interstitial 5S rDNA sites were detected; 2 of the distal sites strictly colocalized with 25S rDNA loci. The 2 intercalary 5S rDNA loci occurred in short arms of 2 chromosomes that conjoined at meiosis. Chromosomes differed as to the amount of AT-rich centric heterochromatin, suggesting involvement of pericentromeric regions in translocations. The possibility of Robertsonian-like rearrangements was discussed. Double target FISH with ribosomal probes along with DAPI fluorescence gave the basis for full chromosome identification in mitosis. The 2 Renner complexes are structurally balanced, both having 5 25S and 4 5S rDNA sites. Centromere clustering, telomere association, a high number of NOR sites, and a strong tendency for formation of joint nucleoli contribute to the preservation of highly polarized Rabl arrangement at interphase. These findings were discussed in relation to meiotic catenation in Rhoeo.Key words: chromosomes, complex heterozygotes, FISH, heterochromatin, interphase, meiotic multivalents, nucleolus, NOR, rDNA, Rhoeo, Renner complexes, translocations.


2019 ◽  
Vol 24 (2) ◽  
pp. 82
Author(s):  
Agus Budi Setiawan ◽  
Ari Wibowo ◽  
Chee How Teo ◽  
Shinji Kikuchi ◽  
Takato Koba

Repetitive DNA sequences are highly abundant in plant genomes and are favorable probes for chromosome identification in plants. However, it is difficult to conduct studies on the details of metaphase chromosome structures in plants with small chromosomes due to their highly condensed status. Therefore, identification of homologous chromosomes for karyotyping and analyzing chromosome structures is a challenging issue for cytogeneticists without specific probes and precise chromosome stages. In this study, five repetitive DNA probes, i.e., 5S and 45S ribosomal DNAs (rDNAs), melon centromeric sequence (Cmcent), cucumber subtelomeric sequence (Type I), and microsatellite (CT)10 repeats, were used to identify primary constrictions and homologous chromosomes for karyotyping. Four and two loci of 45S rDNA were respectively observed on metaphase and pachytene chromosomes of Abelia × grandiflora. Cmcent was detected on both primary constrictions of melon pachytene and metaphase chromosomes. Furthermore, one pair of 5S rDNA signals were hybridized on melon metaphase chromosomes. Eight and two loci of 45S and 5S rDNA were respectively detected on cucumber chromosomes. Type I and (CT)10 probes were specifically hybridized on subtelomeric and interstitial regions on the chromosomes, respectively. These results suggest that repetitive DNA sequences are versatile probes for chromosome identification in plants with small chromosomes, particularly for karyotyping analyses.


Genome ◽  
1997 ◽  
Vol 40 (5) ◽  
pp. 589-593 ◽  
Author(s):  
C. Pedersen ◽  
P. Langridge

Using the Aegilops tauschii clone pAs1 together with the barley clone pHvG38 for two-colour fluorescence in situ hybridization (FISH) the entire chromosome complement of hexaploid wheat was identified. The combination of the two probes allowed easy discrimination of the three genomes of wheat. The banding pattern obtained with the pHvG38 probe containing the GAA-satellite sequence was identical to the N-banding pattern of wheat. A detailed idiogram was constructed, including 73 GAA bands and 48 pAs1 bands. Identification of the wheat chromosomes by FISH will be particularly useful in connection with the physical mapping of other DNA sequences to chromosomes, or for chromosome identification in general, as an alternative to C-banding.Key words: Triticum aestivum, chromosome identification, fluorescence in situ hybridization, repetitive DNA sequences.


Genome ◽  
1995 ◽  
Vol 38 (6) ◽  
pp. 1061-1069 ◽  
Author(s):  
A. Cuadrado ◽  
N. Jouve ◽  
C. Ceoloni

The molecular characterization of heterochromatin in six lines of rye has been performed using fluorescence in situ hybridization (FISH). The highly repetitive rye DNA sequences pSc 119.2, pSc74, and pSc34, and the probes pTa71 and pSc794 containing the 25S–5.8S–18S rDNA (NOR) and the 5S rDNA multigene families, respectively, were used. This allowed the individual identification of all seven rye chromosomes and most chromosome arms in all lines. All varieties showed similar but not identical patterns. A standard in situ hybridization map was constructed following the nomenclature system recommended for C-bands. All FISH sites observed appeared to correspond well with C-band locations, but not all C-banding sites coincided with hybridization sites of the repetitive DNA probes used. Quantitative and qualitative differences between different varieties were found for in situ hybridization response at corresponding sites. Variation between plants and even between homologous chromosomes of the same plant was found in open-pollinated lines. In inbred lines, the in situ pattern of the homologues was practically identical and no variation between plants was detected. The observed quantitative and qualitative differences are consistent with a corresponding variation for C-bands detected both within and between cultivars.Key words: fluorescence in situ hybridization, repetitive DNA, rye, Secale cereale, polymorphism.


2015 ◽  
Vol 145 (3-4) ◽  
pp. 201-217 ◽  
Author(s):  
Michael Schmid ◽  
Claus Steinlein

Mitotic chromosomes of 16 species of the frog genus Xenopus were prepared from kidney and lung cell cultures. In the chromosomes of 7 species, high-resolution replication banding patterns could be induced by treating the cultures with 5-bromodeoxyuridine (BrdU) and deoxythymidine (dT) in succession, and in 6 of these species the BrdU/dT-banded chromosomes could be arranged into karyotypes. In the 3 species of the clade with 2n = 20 and 4n = 40 chromosomes (X. tropicalis, X. epitropicalis, X. new tetraploid 1), as well as in the 3 species with 4n = 36 chromosomes (X. laevis, X. borealis, X. muelleri), the BrdU/dT-banded karyotypes show a high degree of homoeology, though differences were detected between these groups. Translocations, inversions, insertions or sex-specific replication bands were not observed. Minor replication asynchronies found between chromosomes probably involve heterochromatic regions. BrdU/dT replication banding of Xenopus chromosomes provides the landmarks necessary for the exact physical mapping of genes and repetitive sequences. FISH with an X. laevis 5S rDNA probe detected multiple hybridization sites at or near the long-arm telomeric regions in most chromosomes of X. laevis and X. borealis, whereas in X. muelleri, the 5S rDNA sequences are located exclusively at the long-arm telomeres of a single chromosome pair. Staining with the AT base pair-specific fluorochrome quinacrine mustard revealed brightly fluorescing heterochromatic regions in the majority of X. borealis chromosomes which are absent in other Xenopus species.


2017 ◽  
Vol 153 (3) ◽  
pp. 158-164 ◽  
Author(s):  
Manman Qu ◽  
Kunpeng Li ◽  
Yanli Han ◽  
Lei Chen ◽  
Zongyun Li ◽  
...  

Chromosome identification is critical for many aspects of cytogenetic research. However, for Fragaria vesca, definite identification of individual chromosomes is almost impossible because of their small size and high similarity. Here, we demonstrate that bulked oligonucleotide (oligo) probes can be used as chromosome-specific DNA markers for chromosome identification in F. vesca. Oligos specific to entire pseudochromosomes in the draft genome of F. vesca were identified and synthesized as libraries. In all, we synthesized 6 oligo libraries corresponding to 6 pseudochromosomes of F. vesca. These libraries were amplified and labeled as probes for fluorescence in situ hybridization (FISH). Two rounds of multicolor FISH analysis were sequentially conducted on the same metaphase cells with each round including 3 probe libraries, which permitted simultaneous identification of all chromosomes of F. vesca. Moreover, 45S and 5S rDNA were mapped to chromosomes 1, 2, and 7, respectively. A karyotype of metaphase chromosomes was constructed, representing the first FISH-based molecular cytogenetic karyotype of F. vesca. Our study can serve as a basis for future comparative cytogenetic research through cross-species chromosome painting using bulked oligo probes and will facilitate the application of breeding technologies that rely on the identification of chromosomes in the genus Fragaria.


1987 ◽  
Vol 88 (3) ◽  
pp. 327-334
Author(s):  
H. Bultmann ◽  
R. Mezzanotte

We have used endonuclease treatment in situ, followed by Giemsa or ethidium bromide staining, for mapping repetitive sequences on the chromosomes of the flesh fly Sarcophaga bullata and thus for studying extrachromosomal DNA granules in this species. All three restriction enzymes employed (HaeIII, A1uI and HindIII) show the same cytological effects, except for a single interstitial band. In both polytene and mitotic chromosomes, chromatin resistant to these endonucleases presumably includes at least three endonucleases presumably includes at least three previously unrecognized buoyant density satellites (1.663, 1.670 and 1.692 g ml-1 in neutral CsCl), and is predominantly localized in the pericentric regions of all five autosomes. Mitotic treated chromosomes show that the entire rod-shaped X chromosome, but no part of the dot-like Y chromosome, consists of endonuclease-resistant chromatin. The most unusual heterochromatic component of polytene nuclei in this species, the ‘extrachromosomal DNA granules’, are also entirely resistant to digestion with endonucleases. We think that these DNA granules represent dispersed X chromatin and not, as previously assumed, extruded autosomal heterochromatin.


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