In situ hybridization confirms jumping nucleolus organizing regions in Allium

Schubert, Ingo; Wobus, Ulrich

doi:10.1007/bf00328466

Cited by 280 publications

(198 citation statements)

References 10 publications

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“…However, the dispersion of 5S rDNA in C. elegans, C fasciculatum, and V. foetida and the dispersion of 5S and 18-5.8-26S rDNA in Bs of C. euanthes, C. nocturnum, and C. parqui could be due to transposable elements (TEs), since it leads to an increased number of sites in the genome. The transposonmediated mobility of rDNA, proposed for Allium (Schubert and Wobus 1985), was supported by permanent clustering of different TEs with 18-5.8-26S or 5S rDNA (Raskina et al 2008). Cestrum strigilatum and C. intermedium exhibited a concentration of these elements in some terminal regions associated with NORs and hybridization signals on both arms of the Bs (Fregonezi et al 2007).…”

Section: Physical Mapping Of Ribosomal Rna Genes In the Bsmentioning

confidence: 86%

Chromosomal differentiation of Tribe Cestreae (Solanaceae) by analyses of 18-5.8-26S and 5S rDNA distribution

et al. 2014

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Tribe Cestreae is monophyletic with three genera: Cestrum, Sessea, and Vestia. Karyotypically, it is outstanding within Solanaceae by several features: (1) basic number x = 8, (2) large chromosome sizes, (3) complex heterochromatin patterns, (4) occurrence of B-chromosomes (Bs) in Cestrum with particular banding patterns and rDNA sites distribution, and (5) absence of Arabidopsis-type telomeres. Seventeen South American Cestreae species from the three genera were studied using fluorescence in situ hybridization (FISH) with ribosomal DNA regions (5S and 18-5.8-26S) as probes, with the aim of recognizing specific or group-specific chromosomal markers and analyzing karyotype diversity in a systematic and evolutionary context. The first chromosome number report for Cestrum euanthes, C. kunthii, C. lorentzianum, and C. tomentosum is included. Variation in number and distribution of rDNA loci was observed among the species, concerning both As and Bs chromosomes. Despite the constancy of the karyotype and numbers of rDNA loci, the mapping of 18-5.8-26S and 5S rDNA loci allowed to differentiate Cestreae genera and species groups within Cestrum, highlighting the importance of these markers as cytotaxonomic character in this tribe.

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Section: Physical Mapping Of Ribosomal Rna Genes In the Bsmentioning

confidence: 86%

Chromosomal differentiation of Tribe Cestreae (Solanaceae) by analyses of 18-5.8-26S and 5S rDNA distribution

et al. 2014

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“…The rDNA positions are highly polymorphic and well known for their potential intragenomic mobility (Schubert and Wobus, 1985). The occurrence of independent satellite repeats that are homologous to the IGS subrepeats was reported for some solanaceous species, such as tobacco , potato (Stupar et al, 2002) and tomato (Jo et al, 2009).…”

Section: Distribution Of Rdna Variants In the Capsicum Genomementioning

confidence: 99%

Unraveling the sequence dynamics of the formation of genus-specific satellite DNAs in the family solanaceae

Park

Kim

et al. 2010

Heredity

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Tandemly repeated DNAs, referred to as satellite DNAs, often occur in a genome in a genus-specific manner. However, the mechanisms for generation and evolution for these sequences are largely unknown because of the uncertain origins of the satellite DNAs. We found highly divergent genus-specific satellite DNAs that showed sequence similarity with genus-specific intergenic spacers (IGSs) in the family Solanaceae, which includes the genera Nicotiana, Solanum and Capsicum. The conserved position of the IGS between 25S and 18S rDNA facilitates comparison of IGS sequences across genera, even in the presence of very low sequence similarity. Sequence comparison of IGS may elucidate the procedure of the genesis of complex monomer units of the satellite DNAs. Within the IGS of Capsicum species, base substitutions and copy number variation of subrepeat monomers were causes of monomer divergence in IGS sequences. At the level of inter-generic IGS sequences of the family Solanaceae, however, genus-specific motif selection, motif shuffling between subrepeats and differential amplification among motifs were involved in formation of genus-specific IGS. Therefore, the genus-specific satellite DNAs in Solanaceae plants can be generated from differentially organized repeat monomers of the IGS rather than by accumulation of mutations from pre-existent satellite DNAs.

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“…1 or 2). Based on the variability in size, number and chromosomal position of NORs in A/hum species hybrids, Schubert and Wobus (1985) have presented a hypothesis on the interchromosomal mobility of NORs in plant genomes.…”

Section: Evolution Of Nucleolar B Chromosomesmentioning

confidence: 99%

Ribosomal RNA genes in B chromosomes of Crepis capillaris detected by non-radioactive in situ hybridization

Małuszyńska

Schweizer

1989

Heredity

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A non-radioactive in Situ hybridization method using biotin-labelled rDNA has made it possible to localize rRNA genes not only at the secondary constriction in both homologous chromosomes No. 3 of Crepis capillaris but also in the B chromosomes occurring in the plants employed. Very clear dot-like rDNA signals at the telomeres of both arms were observed in all B chromosomes. Histochemical silver staining, which is indicative of transcriptional activity of rRNA gene clusters, resulted in both darkly-staining nucleolar constrictions of chromosomes No. 3 and silver deposits at the telomeres of Bs. We conclude that the B chromosomes of C. capillaris are isochromosomes with active rRNA genes located near both telomeres.

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In situ hybridization confirms jumping nucleolus organizing regions in Allium

Cited by 280 publications

References 10 publications

Chromosomal differentiation of Tribe Cestreae (Solanaceae) by analyses of 18-5.8-26S and 5S rDNA distribution

Chromosomal differentiation of Tribe Cestreae (Solanaceae) by analyses of 18-5.8-26S and 5S rDNA distribution

Unraveling the sequence dynamics of the formation of genus-specific satellite DNAs in the family solanaceae

Ribosomal RNA genes in B chromosomes of Crepis capillaris detected by non-radioactive in situ hybridization

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