Frequent duplication and deletion events in the 5S RNA genes and the associated spacer regions of theTriticeae

Scoles, G. J.; Gill, Bikram S.; Zhao, Xiaohui; Clarke, B. C.; McIntyre, C. Lynne; Chapman, C G D; Appels, R.

doi:10.1007/bf00936713

Cited by 131 publications

(76 citation statements)

References 37 publications

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“…The data revealed: (i) the length of basic unit of the S-genome family of tobacco is the same as the length of basic unit in N. sylvestris, likewise the length of basic unit of the T-genome family of tobacco is the same as the full length unit in N. tomentosiformis; (ii) the T-genome family of tobacco and N. tomentosiformis 5S units have the same GC-rich sub-region that is absent in the S-genome family and N. sylvestris; and (iii) the non-coding spacer of S-genome family has high sequence similarity to the spacer of N. sylvestris while the non-coding spacer of Tgenome family has high sequence similarity to N. tomentosiformis. This organization of 5S units in tobacco in which parental 5S units can be distinguished by length polymorphisms resembles other well-studied plant allopolyploids in the genera Triticum (Scoles et al, 1988) and Gossypium (Cronn et al, 1996).…”

Section: Discussionsupporting

confidence: 59%

“…Alternatively, its origin could be a duplication of pre-existing short elements in the spacer region, and indeed, three GGCCT sites are observed. Sub-repeats are also found in the non-coding spacer of 5S rDNA of other plants (Scoles et al, 1988;Venkateswarlu et al, 1991;Singh et al, 1994) and perhaps amplification/reductions in sub-repeat numbers play a similar role in the evolution of 5S rDNA as they do for 18-26S rDNA (Flavell, 1989;Volkov et al, 1999).…”

Section: Evolution Of 5s Repeats At the Unit Levelmentioning

confidence: 90%

“…Unlike 18-26S rDNA, the 5S sequences showed no such interphase associations, and were regularly well separated across the nucleus (Figure 4). This lack of interphase association may contribute to a lack of interlocus homogenization of the two 5S families in N. tabacum and elsewhere (Scoles et al, 1988;Cronn et al, 1996) The copy number of 5S repeats seems to be a characteristic feature of a given cultivar and is not influenced by environmental or developmental factors (plants and derived calluses had essentially the same number of repeats; data not shown). Interestingly, a decrease in the copy number in one 5S rDNA family in tobacco is often associated with an increase in copy number in the second family suggesting that a mechanism maintaining a relatively fixed number of 5S repeats may be active.…”

Section: Evolution Of 5s Repeats At the Unit Levelmentioning

confidence: 95%

“…It is possible that the two 5S rDNA families in N. tabacum and N. rustica have their origins in the diploid progenitor species. Certainly in the Triticeae (Scoles et al, 1988) and in the Gossypium allopolyploids, G. hirsutum and G. mustelinum (Cronn et al, 1996), two 5S rDNA families have been found that remained closely similar to the diploid progenitor species. In this paper we extend our analysis of 5S rDNA families in tobacco to determine: (i) the organization, location and copy numbers of the two 5S families;…”

Section: Introductionmentioning

confidence: 99%

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Evolution and structure of 5S rDNA loci in allotetraploid Nicotiana tabacum and its putative parental species

et al. 2002

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Nicotiana tabacum (tobacco) is an allotetraploid derived from ancestors of the modern diploids, N. sylvestris and N. tomentosiformis. We identified and characterized two distinct families of 5S ribosomal DNA (rDNA) in N. tabacum; one family had an average 431 bp unit length and the other a 646 bp unit length. In the diploid species, N. sylvestris and N. tomentosiformis, the 5S rDNA unit lengths are 431 bp and 644 bp respectively. The non-coding spacer sequence of the short unit in tobacco had high sequence homology to the spacer of N. sylvestris 5S rDNA, while the longer spacer of tobacco had high homology with the 5S spacer of N. tomentosiformis. This suggests that the two 5S families in tobacco have their origin in the diploid ancestors. The longer spacer sequence had a GC rich sub-region (called the T-genome sub-region) that was absent in the short spacer. Pulsed field gel analysis and fluorescent in situ hybridization to tobacco metaphase chromosomes showed that the two families of

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Section: Discussionsupporting

confidence: 59%

Section: Evolution Of 5s Repeats At the Unit Levelmentioning

confidence: 90%

Section: Evolution Of 5s Repeats At the Unit Levelmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

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Evolution and structure of 5S rDNA loci in allotetraploid Nicotiana tabacum and its putative parental species

et al. 2002

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“…In Th. elongatum, the presence of 5S rDNA in the short arms of chromosomes of the homeologous group 1 and probably 5 has been suggested (Scoles et al, 1988;Dvorák et al, 1989). In Th.…”

Section: Ribosomal Genesmentioning

confidence: 99%

Chromosome characterization in Thinopyrum ponticum (Triticeae, Poaceae) using in situ hybridization with different DNA sequences

et al. 2003

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Thinopyrum ponticum (2n = 10x = 70, JJJJ s J s ) belongs to the Triticeae tribe, and is currently used as a source of pathogen resistance genes in wheat breeding. In order to characterize its chromosomes, the number and position of 45S and 5S rDNA sites, as well as the distribution of the repetitive DNA sequences pAs1 and pSc119.2, were identified by fluorescent in situ hybridization. The number of nucleoli and NORs was also recorded after silver nitrate staining. Seventeen 45S and twenty 5S rDNA sites were observed on the short arms of 17 chromosomes, the 45S rDNA was always located terminally. On three other chromosomes, only the 5S rDNA site was observed. Silver staining revealed a high number of Ag-NORs (14 to 17) on metaphase chromosomes, whereas on interphase nuclei there was a large variation in number of nucleoli (one to 15), most of them (82.8%) ranging between four and nine. The pAs1 probe hybridized to the terminal region of both arms of all 70 chromosomes. In addition, a disperse labeling was observed throughout the chromosomes, except in centromeric and most pericentromeric regions. When the pSc119.2 sequence was used as a probe, terminal labeling was observed on the short arms of 17 chromosomes and on the long arms of five others. The relative position of 45S and 5S rDNA sites, together with the hybridization pattern of pAs1 and pSc119.2 probes, should allow whole chromosomes or chromosome segments of Th. ponticum to be identified in inbred lines of wheat x Th. ponticum.

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PCR, sequencing and PCR–RFLP of the 5S‐rRNA‐NTS region as a tool for the DNA fingerprinting of medicinal and aromatic plants

Varese

Bertea

Maffei

2010

Flavour & Fragrance J

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Molecular genetic methods have several advantages over classical morphological and chemical analyses. For instance, the genetic method requires genotype instead of phenotype, therefore DNA-based techniques have been widely used for rapid identifi cation of herbal medicine and aromatic plants. Using PCR approaches, nanogram quantities of DNA are required to amplify and yield suffi cient amounts of template DNA for molecular genetic analysis. Recently, the molecular discrimination of some higher plant species has been evaluated using sequences of a 5S-rRNA gene spacer region. The variation in the non-transcribed sequence (NTS) region has been used in a number of plant species for studying intraspecifi c variation, mapping 5S rDNA arrays, genome evolution and phylogenetic reconstruction. In this minireview we summarize the potential use of the 5S-rRNA-NTS region as a tool for the DNA fi ngerprinting of medicinal and aromatic plants.

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Frequent duplication and deletion events in the 5S RNA genes and the associated spacer regions of theTriticeae

Cited by 131 publications

References 37 publications

Evolution and structure of 5S rDNA loci in allotetraploid Nicotiana tabacum and its putative parental species

Evolution and structure of 5S rDNA loci in allotetraploid Nicotiana tabacum and its putative parental species

Chromosome characterization in Thinopyrum ponticum (Triticeae, Poaceae) using in situ hybridization with different DNA sequences

PCR, sequencing and PCR–RFLP of the 5S‐rRNA‐NTS region as a tool for the DNA fingerprinting of medicinal and aromatic plants

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