Ribosomal DNA variation and its phylogenetic implication in the genusBrachypodium (Poaceae)

@article{Shi2004RibosomalDV,
  title={Ribosomal DNA variation and its phylogenetic implication in the genusBrachypodium (Poaceae)},
  author={Ying Shi and John Draper and Clive A. Stace},
  journal={Plant Systematics and Evolution},
  year={2004},
  volume={188},
  pages={125-138}
}
The structure of ribosomal DNA ofBrachypodium and several other grass species was investigated using a heterologous rDNA probe from wheat. Several different rDNA families were present among perennial and annual species within the genus. In contrast to the annual species the perennial species exhibited a very low degree of repeat length variation. An extra Eco RI site and a Hin dIII site were observed in the IGS, which distinguishedBrachypodium from other grass genera. The restriction fragment… 
Compact genomes and complex evolution in the genus Brachypodium
TLDR
Evidence is shown that B. distachyon may have a homoploid origin, involving ancestral interspecific hybridisation, although it does not appear to be a component of any of the perennial Eurasian allopolyploids.
Structural organization of the nuclear ribosomal RNA genes in Cannabis and Humulus (Cannabaceae)
TLDR
The structural organization of the nuclear ribosomal DNA (rDNA) of Humulus lupulus, H. japonicus and Cannabis sativa was determined by restriction site mapping and supports the placement of Cannabis and Humulus in one family, Cannabaceae.
Intraspecific polymorphism of ribosomal DNA loci number and morphology in Brachypodium pinnatum and Brachypodium sylvaticum
TLDR
The 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 and it was revealed that the number and chromosome distribution of CMA+ bands are in congruence only with 35S rDNA loci which gave strong FISH signals.
On the hybrid origin of Narcissus biflorus (Amaryllidaceae): analysis of C-banding and rDNA structure
TLDR
Giemsa and fluorochrome banding with DAPI and chromomycin A3, were utilized to assess karyological details which correlate N. biflorus with the parental species: N. tazetta and N. poëticus and indicated that each species has more than one ribosomal gene type.
Comparative cytogenetic analysis of the genomes of the model grass Brachypodium distachyon and its close relatives.
TLDR
The increasing significance of B. distachyon as a model grass emphasizes the need to understand the evolutionary relationships in the genus Brachypodium and to ensure consistency in the biological nomenclature of its species.
Evolution and taxonomic split of the model grass Brachypodium distachyon.
TLDR
The substantial phenotypic, cytogenetic and molecular differences detected among the three B. distachyon sensu lato cytotypes are indicative of major speciation processes within this complex that allow their taxonomic separation into three distinct species.
Phylogeny and Evolution of the Genus Brachypodium
TLDR
The results support the early splits of the annual and short-rhizomatose lineages (B. hybridum in the Holarctic region during the early-Middle Miocene) and a profusion of rapid splits for the perennial lineages since the late Miocene to the Pleistocene in the Mediterranean and Eurasian regions.
Laying the Cytotaxonomic Foundations of a New Model Grass, Brachypodium distachyon (L.) Beauv.
TLDR
In situ hybridization using genomic DNA probes and rDNA markers uncovers a hybrid origin of several of the polyploid ecotypes, and sheds light upon the complex evolution of this species and its close relatives.
EST sequencing and phylogenetic analysis of the model grass Brachypodium distachyon
TLDR
To demonstrate the utility of this EST collection for studying cell wall composition, homologs for the genes involved in the biosynthesis of lignin subunits were identified and reinforced the close relationship of Brachypodium to wheat and barley.
...
...

References

SHOWING 1-10 OF 25 REFERENCES
Polymorphism in ribosomal DNA repeat units of 12 Hordeum species
TLDR
Different distributions of BamHI restriction site maps within the Hordeum sections strengthen the concept of using variation in rDNA restriction sites as a taxonomic character.
Relationships betweenNor-loci from differentTriticeae species
TheNor-loci of polyploid wheats and their putative diploid progenitor species were assayed by probing isolated nuclear DNA with ribosomal DNA spacer sequences (spacer rDNA sequences, isolated by
Variation in the Intergenic Spacer of Ribosomal DNA of Wild Wheat, Triticum dicoccoides. In Israel
The variation in the intergenic spacer of ribosomal DNA (rDNA) of tetraploid wild emmer wheat, Triticum dicoccoides, in Israel was examined in 112 individual plants representing 12 populations tested
Genomic organization of the ribosomal DNA of sorghum and its close relatives
TLDR
The restriction site variability seen between these three genera demonstrated that sorghum and sugarcane are more closely related to each other than either is to maize, and spacer size variation was found to provide a highly sensitive assay for the genetic contribution of different S. bicolor races and other Sorghum species to a Sorghums population.
Ribosomal RNA genes in plants: variability in copy number and in the intergenic spacer
TLDR
Analysis of inheritance indicates that copy number change is rapid, occurring even among somatic cells of individual plants, and that up to 90% or more of the gene copies are superfluous.
Ribosomal DNA spacer-length polymorphisms in barley: mendelian inheritance, chromosomal location, and population dynamics.
TLDR
It is concluded that the rDNA sl variants and/or associated loci are under selection in CCII, which demonstrates that Rrn1 and Rrn2 are useful as new genetic markers.
Cloning and characterization of ribosomal RNA genes from wheat and barley.
TLDR
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-.
The organization and genetics of rDNA length variants in peas
TLDR
Length variation of pea rDNA is organized between long tandem arrays of rDNA repeat, and the rDNA length classes show simple Mendelian inheritance.
...
...