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.

Genome differentiation in Aegilops. 2. Physical mapping of 5S and 18S–26S ribosomal RNA gene families in diploid species

Genome ◽  
1996 ◽  
Vol 39 (6) ◽  
pp. 1150-1158 ◽  
Author(s):  
Ekatherina D. Badaeva ◽  
Bernd Friebe ◽  
Bikram S. Gill
Keyword(s):  
In Situ Hybridization ◽  
Ribosomal Rna ◽  
5S Rdna ◽  
Gene Families ◽  
Aegilops Species ◽  
Ribosomal Rna Gene ◽  
26S Rdna ◽  
Genome Differentiation ◽  
Rdna Loci

The distribution of the 5S and 18S–5.8S–26S (18S–26S) ribosomal RNA (rRNA) gene families on chromosomes of all diploid Aegilops species was studied by in situ hybridization with pTa71 (18S–26S rDNA) and pTa794 (5S rDNA) DNA clones. One major 18S–26S rDNA locus was found in the nucleolus organizer region (NOR) of each of the species Aegilops tauschii and Aegilops uniaristata and two loci were detected in the remaining species. In addition to major NORs, from one to nine minor loci were observed; their numbers and chromosomal locations were species-specific. Some minor loci were polymorphic, whereas others were conserved. One or two 5S rDNA loci were observed in the short arms of the chromosomes of groups 1 and 5 of all diploid Aegilops species except Ae. uniaristata, where one 5S rDNA site was located in the distal part of the long arm of chromosome 1N. The 5S rDNA loci were not associated with NORs; however, the relative positions of two ribosomal RNA gene families were diagnostic for chromosomes of homoeologous groups 1, 5, and 6. Implications of these results for establishing phylogenetic relationships of diploid Aegilops species and mechanisms of genome differentiation are discussed. Key words : wheat, Triticum, Aegilops, 5S rRNA, 18S–26S rRNA, in situ hybridization, evolution.

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.

Genetic and cytogenetic analyses of the A genome of Triticum monococcum. VIII. Localization of rDNAs and characterization of 5S rRNA genes

Genome ◽  
1993 ◽  
Vol 36 (1) ◽  
pp. 77-86 ◽  
Author(s):  
Nam-Soo Kim ◽  
J. Kuspira ◽  
K. Armstrong ◽  
R. Bhambhani
Keyword(s):  
In Situ Hybridization ◽  
5S Rdna ◽  
Triticum Monococcum ◽  
Rrna Genes ◽  
26S Rdna ◽  
Recognition Sites ◽  
Evolutionary Changes ◽  
A Genome ◽  
Chromosome 5A

In situ hybridization with [3H]dCTP labelled pScT7 (5S rDNA) and pTa80 (18S + 26S rDNA) indicated that both hybridized to the terminal regions of two pairs of chromosomes in Triticum monococcum. When the hybridization was performed with a mixture of both probes, only two pairs of chromosome arms were labelled, which suggested that the loci of both genes were located in juxtaposition to one another. Both probes labelled one pair of sites more heavily than the other. Southern analysis of 5S with BamHI-digested DNA from 12 accessions of T. monococcum (including T. urartu) produced two superimposed ladders of approximate sizes of 500 and 330 bp, which differ from T. aestivum in which 500- and 420-bp ladders were found. The 500-bp ladder is derived from chromosome 5A (5SDna-A2) and the 330-bp ladder from chromosome 1A (5SDna-A1). The recognition site for SstI was present in the long spacer region but absent in the short spacer as in T. aestivum; however, unlike T. aestivum, there were HaeIII (GGCC) and HindIII (AAGCTT) recognition sites in the short spacer region. The TaqI recognition sites (TCGA) in the long and short spacer regions are probably more highly methylated in T. monococcum than in T. aestivum. The results have implications regarding the evolutionary changes that occurred in the A genome of the hexaploid compared with the diploid.Key words: Triticum monococcum, 5S rDNA, 18S + 26S rDNA, in situ hybridization, Southern hybridization, restriction fragments, methylation.

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.

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.

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.

Chromosomal mapping of 18S–28S and 5S rRNA genes by two-colour fluorescent in situ hybridization in six sturgeon species

Genome ◽  
2003 ◽  
Vol 46 (3) ◽  
pp. 473-477 ◽  
Author(s):  
Francesco Fontana ◽  
Massimo Lanfredi ◽  
Leonardo Congiu ◽  
Marilena Leis ◽  
Milvia Chicca ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Close Association ◽  
5S Rdna ◽  
28S Rdna ◽  
5S Rrna ◽  
Chromosomal Mapping ◽  
Rrna Genes ◽  
Acipenser Baerii ◽  
Sturgeon Species

The number and distribution of the 18S–28S and 5S rRNA (rDNA) gene sequences were examined on mitotic chromosomes of six sturgeon species by two-colour in situ hybridization. Four of the six species, Huso huso, Acipenser stellatus, Acipenser sturio, and Acipenser ruthenus, with about 120 chromosomes, showed from six to eight 18S–28S rDNA signals, while 5S rDNA signals were on only one chromosome pair. The two species with 250–270 chromosomes, Acipenser baerii and Acipenser transmontanus, showed from 10 to 12 18S–28S sites and two chromosome pairs bearing 5S rDNA signals. In all examined species, the rather intense 5S rDNA signals apparently overlapped those of 18S–28S rDNA. These data support the diploid–tetraploid relationships between the two chromosome groups of sturgeons. The close association between the two rDNA families in species belonging to an ancestral fish order, such as Acipenseriformes, supports the hypothesis that the association represents a primitive condition.Key words: Acipenseriformes, FISH, fish cytogenetics, ribosomal genes.

Characterization of genome in tetraploid StY species of Elymus (Triticeae: Poaceae) using sequential FISH and GISH

Genome ◽  
2017 ◽  
Vol 60 (8) ◽  
pp. 679-685 ◽  
Author(s):  
Ruijuan Liu ◽  
Richard R.-C. Wang ◽  
Feng Yu ◽  
Xingwang Lu ◽  
Quanwen Dou
Keyword(s):  
In Situ Hybridization ◽  
5S Rdna ◽  
Type I ◽  
Genomic Variations ◽  
26S Rdna ◽  
Close Relationship ◽  
Species Type ◽  
Sequential Fish

Genomes of ten species of Elymus, either presumed or known as tetraploid StY, were characterized using fluorescence in situ hybridization (FISH) and genomic in situ hybridization (GISH). These tetraploid species could be grouped into three categories. Type I included StY genome reported species—Roegneria pendulina, R. nutans, R. glaberrima, R. ciliaris, and Elymus nevskii, and StY genome presumed species—R. sinica, R. breviglumis, and R. dura, whose genome could be separated into two sets based on different GISH intensities. Type I genome constitution was deemed as putative StY. The St genome were mainly characterized with intense hybridization with pAs1, fewer AAG sites, and linked distribution of 5S rDNA and 18S-26S rDNA, while the Y genome with less intense hybridization with pAs1, more varied AAG sites, and isolated distribution of 5S rDNA and 18S-26S rDNA. Nevertheless, further genomic variations were detected among the different StY species. Type II included E. alashanicus, whose genome could be easily separated based on GISH pattern. FISH and GISH patterns suggested that E. alashanicus comprised a modified St genome and an unknown genome. Type III included E. longearistatus, whose genome could not be separated by GISH and was designated as StlYl. Notably, a close relationship between Sl and Yl genomes was observed.

Physical mapping of 5S rDNA loci by direct-cloned biotinylated probes in barley chromosomes

Genome ◽  
1994 ◽  
Vol 37 (1) ◽  
pp. 105-111 ◽  
Author(s):  
K. Fukui ◽  
Y. Kamisugi ◽  
F. Sakai
Keyword(s):  
In Situ Hybridization ◽  
5S Rdna ◽  
Coding Region ◽  
Interphase Nuclei ◽  
Noncoding Regions ◽  
Direct Cloning ◽  
Rdna Loci ◽  
Flanking Region ◽  
Biotinylated Probes

5S rDNA loci have been mapped on barley chromosomes by in situ hybridization using five reciprocal translocation lines. Two kinds of DNA probes covering either the 5S rDNA coding region or the 5S rDNA coding and flanking noncoding regions were used. They were prepared by direct cloning from interphase nuclei and simultaneous direct labeling in PCR. Four 5S rDNA loci were detected in a haploid genome by the 5S rDNA coding region, whereas in addition, the four or six 5S rDNA related sites, depending on the variety used, were revealed by the probe covering the flanking region. The four 5S rDNA loci revealed and mapped on the barley chromosomes: 2 (2I), 3 (3I), 1 (7I), and 4 (4I) were designated 5SRrn-I1, 5SRrn-I2, 5SRrn-I3 and 5SRrn-I4, respectively, in descending order of copy number of 5S rRNA genes.Key words: Hordeum vulgare, 5S rDNA, in situ hybridization, direct cloning, direct labeling.

Genome size, heterochromatin organisation, and ribosomal gene mapping in four species of Ribes

2003 ◽  
Vol 81 (11) ◽  
pp. 1049-1057 ◽  
Author(s):  
Joëlle Chiche ◽  
Spencer C Brown ◽  
Jean-Claude Leclerc ◽  
Sonja Siljak-Yakovlev
Keyword(s):  
Flow Cytometry ◽  
Genome Size ◽  
Nuclear Dna ◽  
5S Rdna ◽  
Ribosomal Gene ◽  
Fluorochrome Banding ◽  
Genome Organisation ◽  
Satellite Chromosome ◽  
26S Rdna

Four wild Ribes species (Ribes alpinum L., Ribes petraeum Wulf., Ribes rubrum L., and Ribes uva- crispa L.; all 2n = 2x = 16) were surveyed for their chromosome and genome organisation. Their genome size was assessed using flow cytometry. Ribes alpinum had 5.3% more nuclear DNA than did the three other species, whose average was 2C = 1.91 pg with 40.4% GC. In addition, GC- and AT-rich heterochromatin and rDNA (18S–5.8S–26S and 5S) patterns were studied using fluorochrome banding and double-target fluorescence in situ hybridization (FISH), respectively. Only GC-rich heterochromatin was detected, co-localizing with 18S–26S rDNA. Fluorochrome banding and FISH patterns revealed marked differences between species. Ribes alpinum and R. uva-crispa differed from R. rubrum and R. petraeum by the number of 18S–26S sites and the localization of 5S rDNA. Ribes alpinum and R. uva-crispa were differentiated by the number of 5S sites. Ribes rubrum and R. petraeum also differed by the number of 5S sites and by the size of the GC-rich band on the satellite chromosome pair. These results should contribute to a better understanding of phylogenetic relationships among these species.Key words: Ribes, flow cytometry, fluorochrome banding, FISH, rDNA, NORs.

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