Journal ArticleDOI
Physical mapping of rDNA loci in Brassica species.
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TLDR
The number of major rDNA loci (the genes coding for 18S-5.8S-26S rRNA) was investigated in the economically important Brassica species and their wild relatives by in situ hybridization of an rDNA probe to metaphase chromosomes and interphase nuclei, indicating that the number of loci has been reduced during evolution.Abstract:
The number of major rDNA loci (the genes coding for 18S–5.8S–26S rRNA) was investigated in the economically important Brassica species and their wild relatives by in situ hybridization of an rDNA probe to metaphase chromosomes and interphase nuclei. The diploid species B. nigra (B genome) has two major pairs of rDNA loci, B. oleracea (C genome) has two major pairs and one minor pair of loci, while B. campestris (A genome) has five pairs of loci. Among the three tetraploid species arising from these three diploid ancestors, B. carinata (BBCC genomes) has four loci, B. juncea (AABB genomes) has five major pairs and one minor pair of loci, and B. napus (AACC genomes) has six pairs of loci, indicating that the number of loci has been reduced during evolution. The complexity of the known rDNA restriction fragment length polymorphism patterns gave little indication of number of rDNA loci. It is probable that chromosome rearrangements have occurred during evolution of the amphidiploid species. The data will be u...read more
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Genome evolution in polyploids
TL;DR: Processes and mechanisms of gene and genome evolution in polyploids are reviewed, including the role of transposable elements in structural and regulatory gene evolution; processes and significance of epigenetic silencing; underlying controls of chromosome pairing and mechanisms and functional significance of rapid genome changes are reviewed.
Journal ArticleDOI
Characterisation of the double genome structure of modern sugarcane cultivars (Saccharum spp.) by molecular cytogenetics.
Angélique D'Hont,Laurent Grivet,Philippe Feldmann,Srinivas Rao,Nils Berding,Jean-Christophe Glaszmann +5 more
TL;DR: In this article, the chromosomes contributed by these two species in an interspecific F1 hybrid and a cultivated clone, R570, were identified using comparative genomic DNA in situ hybridization.
Journal ArticleDOI
Transcriptional analysis of nucleolar dominance in polyploid plants: Biased expression/silencing of progenitor rRNA genes is developmentally regulated in Brassica
Z. Jeffrey Chen,Craig S. Pikaard +1 more
TL;DR: In Brassica napus, rRNA genes silenced in vegetative tissues were found to be expressed in all floral organs, arguing against the hypothesis that passage through meiosis is needed to reactivate suppressed genes.
Journal ArticleDOI
Centromeric repetitive DNA sequences in the genus Brassica.
TL;DR: Representatives of two major repetitive DNA sequence families from the diploid Brassica species B. campestris and B. oleracea were isolated, sequenced and localized to chromosomes by in situ hybridization, indicating relatively rapid homogenization and copy number evolution since the origin of the tetraploid species.
Journal ArticleDOI
Physical mapping of rRNA genes by fluorescent in-situ hybridization and structural analysis of 5S rRNA genes and intergenic spacer sequences in sugar beet (Beta vulgaris).
TL;DR: The use of fluorescent in-situ hybridization, complemented by molecular data, for gene mapping and for integrating genetic and physical maps of beet species is discussed.
References
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Journal ArticleDOI
A revised medium for rapid growth and bio assays with tobacco tissue cultures
Toshio Murashige,Folke Skoog +1 more
TL;DR: In vivo redox biosensing resolves the spatiotemporal dynamics of compartmental responses to local ROS generation and provide a basis for understanding how compartment-specific redox dynamics may operate in retrograde signaling and stress 67 acclimation in plants.
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Nuclear DNA Amounts in Angiosperms
Michael D. Bennett,J. B. Smith +1 more
TL;DR: This paper lists absolute nuclear DNA amounts for 753 angiosperm species, primarily for reference purposes, and so the species are listed in alphabetical order, as this was felt to be more helpful to cyto- and biochemists whom, it is anticipated, will be among its major users.
Journal ArticleDOI
Cloning and characterization of ribosomal RNA genes from wheat and barley
W.L. Gerlach,J.R. Bedbrook +1 more
TL;DR: Comparison of Hae III and Hpa II digestion of cereal rDNAs and the cloned repeats suggests that most methylated cytosines in natural rDNA are in -CpG-.
Journal ArticleDOI
Delineation of individual human chromosomes in metaphase and interphase cells by in situ suppression hybridization using recombinant DNA libraries
TL;DR: A method of in situ hybridization for visualizing individual human chromosomes from pter to qter, both in metaphase spreads and interphase nuclei, is reported and should be useful for both karyotypic studies and for the analysis of chromosome topography in interphase cells.
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