Molecular cytogenetic analysis ofAegilops cylindrica Host

Genome ◽  
1999 ◽  
Vol 42 (3) ◽  
pp. 497-503 ◽  
Author(s):  
Gabriella Linc ◽  
Bernd R Friebe ◽  
Ralf G Kynast ◽  
Marta Molnar-Lang ◽  
Bela Köszegi ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
5S Rdna ◽  
Rdna Locus ◽  
Fish Analysis ◽  
Aegilops Cylindrica ◽  
Fish Genome ◽  
C Banding ◽  
Rdna Loci ◽  
25S Rdna

The genomic constitution of Aegilops cylindrica Host (2n = 4x = 28, DcDcCcCc) was analyzed by C-banding, genomic in situ hybridization (GISH), and fluorescence in situ hybridization (FISH) using the DNA clones pSc119, pAs1, pTa71, and pTA794. The C-banding patterns of the Dc- and Cc-genome chromosomes of Ae. cylindrica are similar to those of D-and C-genome chromosomes of the diploid progenitor species Ae. tauschii Coss. and Ae. caudata L., respectively. These similarities permitted the genome allocation and identification of the homoeologous relationships of the Ae. cylindrica chromosomes. FISH analysis detected one major 18S-5.8S-25S rDNA locus in the short arm of chromosome 1Cc. Minor 18S-5.8S-25S rDNA loci were mapped in the short arms of 5Dc and 5Cc. 5S rDNA loci were identified in the short arm of chromosomes 1Cc, 5Dc, 5Cc, and 1Dc. GISH analysis detected intergenomic translocation in three of the five Ae. cylindrica accessions. The breakpoints in all translocations were non-centromeric with similar-sized segment exchanges.Key words: Aegilops cylindrica, C-banding, GISH, FISH, genome evolution.

Chromosomal localization of two novel repetitive sequences isolated from the Chenopodium quinoa Willd. genome

Genome ◽  
2011 ◽  
Vol 54 (9) ◽  
pp. 710-717 ◽  
Author(s):  
B. Kolano ◽  
B.W. Gardunia ◽  
M. Michalska ◽  
A. Bonifacio ◽  
D. Fairbanks ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Repetitive Dna ◽  
Dna Sequences ◽  
Repetitive Sequences ◽  
Chenopodium Quinoa ◽  
5S Rdna ◽  
Rrna Gene ◽  
Fish Analysis ◽  
Rdna Loci

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.

FISH-mapping of rDNAs and Arabidopsis BACs on pachytene complements of selected Brassicas

Genome ◽  
2002 ◽  
Vol 45 (1) ◽  
pp. 189-197 ◽  
Author(s):  
Piotr A Ziolkowski ◽  
Jan Sadowski
Keyword(s):  
In Situ Hybridization ◽  
Physical Mapping ◽  
5S Rdna ◽  
Artificial Chromosome ◽  
Rdna Locus ◽  
Fish Analysis ◽  
45S Rdna ◽  
Fish Mapping ◽  
Rdna Sequences

To improve resolution of physical mapping on Brassica chromosomes, we have chosen the pachytene stage of meiosis where incompletely condensed bivalents are much longer than their counterparts at mitotic metaphase. Mapping with 5S and 45S rDNA sequences demonstrated the advantage of pachytene chromosomes in efficient physical mapping and confirmed the presence of a novel 5S rDNA locus in Brassica oleracea, initially identified by genetic mapping using restriction fragment length polymorphism (RFLP). Fluorescence in situ hybridization (FISH) analysis visualized the presence of the third 5S rDNA locus on the long arm of chromosome C2 and confirmed the earlier reports of two 45S rDNA loci in the B. oleracea genome. FISH mapping of low-copy sequences from the Arabidopsis thaliana bacterial artificial chromosome (BAC) clones on the B. oleracea chromosomes confirmed the expectation of efficient and precise physical mapping of meiotic bivalents based on data available from A. thaliana and indicated conserved organization of these two BAC sequences on two B. oleracea chromosomes. Based on the heterologous in situ hybridization with BACs and their mapping applied to long pachytene bivalents, a new approach in comparative analysis of Brassica and A. thaliana genomes is discussed.Key words: Brassicaceae, pachytene chromosomes, FISH, rDNA, BACs.

FISH analysis of Zanthoxylum armatum based on oligonucleotides for 5S rDNA and (GAA)6

Genome ◽  
2018 ◽  
Vol 61 (9) ◽  
pp. 699-702 ◽  
Author(s):  
Xiaomei Luo ◽  
Juncheng Liu ◽  
Jingyan Wang ◽  
Wei Gong ◽  
Liang Chen ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
5S Rdna ◽  
Fish Analysis ◽  
Oligonucleotide Probes ◽  
Mitotic Metaphase ◽  
Metaphase Chromosomes ◽  
Zanthoxylum Armatum ◽  
Rdna Loci ◽  
Cytogenetic Studies

Fluorescence in situ hybridization (FISH) using oligonucleotide probes for (GAA)6 (18 bp) and ribosomal DNA (rDNA) (5S rDNA, 41 bp) was applied to analyse Zanthoxylum armatum. (GAA)6 loci were detected on the pericentromeric regions of five chromosome pairs, and 5S rDNA loci were also detected on the pericentromeric regions of another two chromosome pairs. The densities and locations of (GAA)6 and 5S rDNA signals varied between individual chromosomes. High-intensity (GAA)6 signals were detected at the centromeres of two large and two smaller metacentric chromosomes. Relatively strong (GAA)6 signals were detected at the centromeres of two relatively small metacentric chromosomes, although strong 5S rDNA signals were detected at the centromeres of two additional smaller metacentric chromosomes. Weak (GAA)6 signals were detected at the centromeres of four large metacentric chromosomes, whereas weak 5S rDNA signals were detected at the centromeres of two smaller metacentric chromosomes. The remaining chromosomes exhibited no signals. Zanthoxylum armatum had 2n = ∼128. The lengths of the mitotic metaphase chromosomes ranged from 1.22 to 2.34 μm. Our results provide information that may be beneficial for future cytogenetic studies and could contribute to the physical assembly of the Zanthoxylum genome.

The use of double fluorescence in situ hybridization to physically map the positions of 5S rDNA genes in relation to the chromosomal location of 18S–5.8S–26S rDNA and a C genome specific DNA sequence in the genus Avena

Genome ◽  
1996 ◽  
Vol 39 (3) ◽  
pp. 535-542 ◽  
Author(s):  
Concha Linares ◽  
Juan González ◽  
Esther Ferrer ◽  
Araceli Fominaya
Keyword(s):  
In Situ Hybridization ◽  
Dna Sequence ◽  
Diploid Species ◽  
5S Rdna ◽  
Rdna Genes ◽  
26S Rdna ◽  
A Genome ◽  
Rdna Loci ◽  
C Genome

A physical map of the locations of the 5S rDNA genes and their relative positions with respect to 18S–5.8S–26S rDNA genes and a C genome specific repetitive DNA sequence was produced for the chromosomes of diploid, tetraploid, and hexaploid oat species using in situ hybridization. The A genome diploid species showed two pairs of rDNA loci and two pairs of 5S loci located on both arms of one pair of satellited chromosomes. The C genome diploid species showed two major pairs and one minor pair of rDNA loci. One pair of subtelocentric chromosomes carried rDNA and 5S loci physically separated on the long arm. The tetraploid species (AACC genomes) arising from these diploid ancestors showed two pairs of rDNA loci and three pairs of 5S loci. Two pairs of rDNA loci and 2 pairs of 5S loci were arranged as in the A genome diploid species. The third pair of 5S loci was located on one pair of A–C translocated chromosomes using simultaneous in situ hybridization with 5S rDNA genes and a C genome specific repetitive DNA sequence. The hexaploid species (AACCDD genomes) showed three pairs of rDNA loci and six pairs of 5S loci. One pair of 5S loci was located on each of two pairs of C–A/D translocated chromosomes. Comparative studies of the physical arrangement of rDNA and 5S loci in polyploid oats and the putative A and C genome progenitor species suggests that A genome diploid species could be the donor of both A and D genomes of polyploid oats. Key words : oats, 5S rDNA genes, 18S–5.8S–26S rDNA genes, C genome specific repetitive DNA sequence, in situ hybridization, genome evolution.

scholarly journals Fluorescence In Situ Hybridization (FISH) Analysis of the Locations of the Oligonucleotides 5S rDNA, (AGGGTTT)3, and (TTG)6 in Three Genera of Oleaceae and Their Phylogenetic Framework

Genes ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 375 ◽  
Author(s):  
Xiaomei Luo ◽  
Juncheng Liu
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
5S Rdna ◽  
Fish Analysis ◽  
Cytogenetic Map ◽  
Ligustrum Lucidum ◽  
Starting Point ◽  
Central Regions ◽  
Almost All

We report the cytogenetic map for a collection of species in the Oleaceae, and test similarities among the karyotypes relative to their known species phylogeny. The oligonucleotides 5S ribosomal DNA (rDNA), (AGGGTTT)3, and (TTG)6 were used as fluorescence in situ hybridization (FISH) probes to locate the corresponding chromosomes in three Oleaceae genera: Fraxinus pennsylvanica, Syringa oblata, Ligustrum lucidum, and Ligustrum × vicaryi. Forty-six small chromosomes were identified in four species. (AGGGTTT)3 signals were observed on almost all chromosome ends of four species, but (AGGGTTT)3 played no role in distinguishing the chromosomes but displayed intact chromosomes and could thus be used as a guide for finding chromosome counts. (TTG)6 and 5S rDNA signals discerned several chromosomes located at subterminal or central regions. Based on the similarity of the signal pattern (mainly in number and location and less in intensity) of the four species, the variations in the 5S rDNA and (TTG)6 distribution can be ordered as L. lucidum < L. × vicaryi < F. pennsylvanica < S. oblata. Variations have observed in the three genera. The molecular cytogenetic data presented here might serve as a starting point for further larger-scale elucidation of the structure of the Oleaceae genome, and comparison with the known phylogeny of Oleaceae family.

Detection of a variable number of 18S-5.8S-26S and 5S ribosomal DNA loci by fluorescent in situ hybridization in diploid and tetraploid Arachis species

Genome ◽  
1999 ◽  
Vol 42 (1) ◽  
pp. 52-59 ◽  
Author(s):  
S N Raina ◽  
Y Mukai
Keyword(s):  
In Situ Hybridization ◽  
5S Rdna ◽  
Gene Families ◽  
Ribosomal Gene ◽  
Rrna Genes ◽  
Tetraploid Species ◽  
Arachis Species ◽  
26S Rdna ◽  
Rdna Loci

In order to obtain new information on the genome organization of Arachis ribosomal DNA, more particularly among A. hypogaea and its close relatives, the distribution of the 18S-5.8S-26S and 5S ribosomal RNA gene families on the chromosomes of 21 diploid and tetraploid Arachis species, selected from six of nine taxonomic sections, was analyzed by in situ hybridization with pTa71 (18S-5.8S-26S rDNA) and pTa794 (5S rDNA) clones. Two major 18S-5.8S-26S rDNA loci with intense signals were found in the nucleolus organizer regions (NOR) of each of the diploid and tetraploid species. In addition to extended signals at major NORs, two to six medium and (or) minute-sized signals were also observed. Variability in the number, size, and location of 18S-5.8S-26S sites could generally distinguish species within the same genome as well as between species with different genomes. The use of double fluorescence in situ hybridization enabled us to locate the positions of 5S rRNA genes in relation to the chromosomal location of 18S-5.8S-26S rRNA genes in Arachis chromosomes which were difficult to karyotype. Two or four 5S rDNA loci and 18S-5.8S-26S rDNA loci were generally located on different chromosomes. The tandemly repeated 5S rDNA sites were diagnostic for T and C genomes. In one species, each of B and Am genomes, the two ribosomal gene families were observed to occur at the same locus. Barring A. ipaensis and A. valida, all the diploid species had characteristic centromeric bands in all the 20 chromosomes. In tetraploid species A. hypogaea and A. monticola only 20 out of 40 chromosomes showed centromeric bands. Comparative studies of distribution of the two ribosomal gene families, and occurrence of centromeric bands in only 20 chromosomes of the tetraploid species suggests that A. villosa and A. ipaensis are the diploid progenitors of A. hypogaea and A. monticola. This study excludes A. batizocoi as the B genome donor species for A. hypogaea and A. monticola.Key words: Arachis species, 5S rRNA, 18S-5.8S-26S rRNA, in situ hybridization, evolution.

Chromosomal localization and characterization of rDNA loci in the Brassica A and C genomes

Genome ◽  
1997 ◽  
Vol 40 (4) ◽  
pp. 582-587 ◽  
Author(s):  
R. J. Snowdon ◽  
W. Köhler ◽  
A. Köhler
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Ribosomal Dna ◽  
Diploid Species ◽  
Rdna Locus ◽  
Chromosome Morphology ◽  
Rdna Site ◽  
A Genome ◽  
Rdna Loci

Using fluorescence in situ hybridization, we located ribosomal DNA loci on prometaphase chromosomes of the diploid species Brassica rapa and Brassica oleracea and their amphidiploid Brassica napus. Based on comparisons of chromosome morphology and hybridization patterns, we characterized the individual B. napus rDNA loci according to their presumed origins in the Brassica A and C genomes. As reported in other studies, the sum of rDNA loci observed on B. rapa (AA genome) and B. oleracea (CC genome) chromosomes was one greater than the total number of loci seen in their amphidiploid B. napus (AACC). Evidence is presented that this reduction in B. napus rDNA locus number results from the loss of the smallest A genome rDNA site in the amphidiploid.Key words: Brassica, fluorescence in situ hybridization, ribosomal DNA, rDNA.

Genetic and chromosomal localization of the 5S rDNA locus in sugar beet (Beta vulgaris L.)

Genome ◽  
1997 ◽  
Vol 40 (2) ◽  
pp. 171-175 ◽  
Author(s):  
J. Schondelmaier ◽  
T. Schmidt ◽  
C. Jung ◽  
J. S. Heslop-Harrison
Keyword(s):  
In Situ Hybridization ◽  
Linkage Group ◽  
Sugar Beet ◽  
Beta Vulgaris ◽  
5S Rdna ◽  
Rdna Locus ◽  
5S Rrna ◽  
Rrna Genes ◽  
Rrna Gene

A digoxigenin-labelled 5S rDNA probe containing the 5S rRNA gene and the adjacent intergenic spacer was used for in situ hybridization to metaphase and interphase chromosomes of a trisomic stock from sugar beet (Beta vulgaris L.). Three chromosomes of primary trisomic line IV (T. Butterfass. Z. Bot. 52: 46–77. 1964) revealed signals close to the centromeres. Polymorphisms of 5S rDNA repeats in a segregating population were used to map genetically the 5S rRNA genes within a cluster of markers in linkage group II of sugar beet. The concentration of genetic markers around the centromere presumably reflects the suppressed recombination frequency in centromeric regions. The correlation of physical and genetic data allowed the assignment of a linkage group to sugar beet chromosome IV according to line IV of the primary trisomics.Key words: Beta vulgaris, sugar beet, 5S rRNA, in situ hybridization, RFLPs, trisomics.

scholarly journals Intraspecific polymorphism of ribosomal DNA loci number and morphology in Brachypodium pinnatum and Brachypodium sylvaticum

2012 ◽  
Vol 17 (4) ◽  
Author(s):  
Ewa Breda ◽  
Elzbieta Wolny ◽  
Robert Hasterok
Keyword(s):  
5S Rdna ◽  
Staining Technique ◽  
Rdna Locus ◽  
Chromosomal Distribution ◽  
Metaphase Chromosomes ◽  
Brachypodium Sylvaticum ◽  
Rdna Sites ◽  
Rdna Loci ◽  
35S Rdna ◽  
25S Rdna

AbstractThe genus Brachypodium has become the target of extensive cytomolecular studies since one of its representatives, B. distachyon, has been accepted as a model plant for temperate cereals and forage grasses. Recent preliminary studies suggested that intraspecific rDNA polymorphism can occur in at least two members of the genus, B. sylvaticum and B. pinnatum, so the aim of this study was to further analyse this phenomenon. FISH with 25S rDNA and 5S rDNA probes was performed on somatic metaphase chromosomes, supplemented by the silver staining technique which distinguishes transcriptionally active from inactive 18S-5.8S-25S rDNA loci. The number, size and chromosomal distribution of 5S rDNA loci were very constant: two loci were invariably observed in all studied diploid accessions of both species, while four 5S rDNA loci were present in the tetraploid B. pinnatum. In contrast to 5S rDNA loci, those of the 35S rDNA were more variable. Two or three loci were observed in the diploid B. pinnatum and four in tetraploid accessions. In chromosome complements of B. sylvaticum accessions from two to six 35S rDNA sites were detected. Regardless of total rDNA locus number, only two were transcriptionally active in diploid accessions of both species, while two or four were active in the tetraploid B. pinnatum. Additionally, the fluorescent CMA/DAPI banding method was used to identify the relation between rDNA sites and CMA+ bands. It was revealed that the number and chromosomal distribution of CMA+ bands are in congruence only with 35S rDNA loci which gave strong FISH signals.

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.

Sign in / Sign up

Export Citation Format

Share Document