Variability in rDNA loci in the genus Oryza detected through fluorescence in situ hybridization

1994 ◽  
Vol 87 (8) ◽  
pp. 893-899 ◽  
Author(s):  
K. Fukui ◽  
N. Ohmido ◽  
G. S. Khush
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Rdna Loci ◽  
Genus Oryza

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.

Distribution of 45S rDNA in Modern Rose Cultivars (Rosa hybrida), Rosa rugosa, and Their Interspecific Hybrids Revealed by Fluorescence in situ Hybridization

2016 ◽  
Vol 149 (3) ◽  
pp. 226-235 ◽  
Author(s):  
Xiao-Liu Ding ◽  
Ting-Liang Xu ◽  
Jing Wang ◽  
Le Luo ◽  
Chao Yu ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Interspecific Hybrids ◽  
Evolutionary Dynamics ◽  
The Other ◽  
45S Rdna ◽  
Expected Number ◽  
Rdna Sites ◽  
Rdna Loci

To elucidate the evolutionary dynamics of the location and number of rDNA loci in the process of polyploidization in the genus Rosa, we examined 45S rDNA sites in the chromosomes of 6 modern rose cultivars (R. hybrida), 5 R. rugosa cultivars, and 20 hybrid progenies by fluorescence in situ hybridization. Variation in the number of rDNA sites in parents and their interspecific hybrids was detected. As expected, 4 rDNA sites were observed in the genomes of 4 modern rose cultivars, while 3 hybridization sites were observed in the 2 others. Two expected rDNA sites were found in 2 R. rugosa cultivars, while in the other 3 R. rugosa cultivars 4 sites were present. Among the 20 R. hybrida × R. rugosa offspring, 13 carried the expected number of rDNA sites, and 1 had 6 hybridization sites, which exceeded the expected number by far. The other 6 offspring had either 2 or 3 hybridization sites, which was less than expected. Differences in the number of rDNA loci were observed in interspecific offspring, indicating that rDNA loci exhibit instability after distant hybridization events. Abnormal chromosome pairing may be the main factor explaining the variation in rDNA sites during polyploidization.

Variability in rDNA loci in Iberian species of the genus Zabrus (Coleoptera: Carabidae) detected by fluorescence in situ hybridization

Genome ◽  
2000 ◽  
Vol 43 (1) ◽  
pp. 22-28 ◽  
Author(s):  
JF Sánchez-Gea ◽  
J Serrano ◽  
J Galián
Keyword(s):  
In Situ Hybridization ◽  
Chromosome Number ◽  
Fluorescence In Situ Hybridization ◽  
Ribosomal Dna ◽  
Ground Beetle ◽  
Morphological Characters ◽  
Rdna Sites ◽  
Rdna Loci ◽  
Numerical Variation

Fluorescence in situ hybridization (FISH) with a PCR-amplified 18S ribosomal probe was used to map rDNA loci in 19 taxa of the ground beetle genus Zabrus (2n = 47-63) from the Iberian Peninsula. A quantitative and qualitative variation has been observed among related species, subspecies, populations, and even individuals. The number of rDNA-carrying chromosomes varies from 2 to 12, and the extent of the signal from small dots to entire arms. Changes altering the number of rDNA clusters seem to be uncoupled from the variation found in the chromosome number. Mechanisms that explain the numerical variation and spreading of rDNA clusters throughout the genome within the genus Zabrus are briefly discussed. No concordance between the pattern of rDNA sites and the phylogenetic relationships as based on morphological characters has been found. Key words: Carabidae, Coleoptera, fluorescence in situ hybridization, polymorphism, ribosomal DNA, Zabrus.

Preliminary karyotype and chromosomal localization of ribosomal DNA sites in white spruce using fluorescence in situ hybridization

Genome ◽  
1993 ◽  
Vol 36 (2) ◽  
pp. 310-316 ◽  
Author(s):  
Garth R. Brown ◽  
Vindhya Amarasinghe ◽  
Gyula Kiss ◽  
John E. Carlson
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Ribosomal Dna ◽  
Dna Sequences ◽  
White Spruce ◽  
Confocal Laser ◽  
Metaphase Chromosomes ◽  
Rdna Sites ◽  
Rdna Loci

We have localized the major ribosomal DNA (rDNA) loci on metaphase chromosomes and in interphase nuclei of white spruce (2n = 24) by fluorescence in situ hybridization. Hybridization sites of the biotin-labelled rDNA probe were detected using antibody–fluorochrome conjugates and a confocal laser scanning microscope. White spruce has at least 12, and possibly as many as 14, rDNA sites, 1 site present on each of seven separate chromosome pairs. This is one of the highest numbers of rDNA loci yet reported among plant species. The position of the rDNA loci together with secondary constriction patterns permit, for the first time, all homologous pairs of white spruce chromosomes to be distinguished. We discuss the application of molecular cytogenetics in studies relating to the organization and evolution of DNA sequences within conifer genomes.Key words: fluorescence in situ hybridization, Picea, rDNA, karyotype.

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