The fate of 35S rRNA genes in the allotetraploid grass Brachypodium hybridum
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Dosyalar
Tarih
2020
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Blackwell Publishing Ltd
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Nucleolar dominance (ND) consists of the reversible silencing of 35S/45S rDNA loci inherited from one of the ancestors of an allopolyploid. The molecular mechanisms by which one ancestral rDNA set is selected for silencing remain unclear. We applied a combination of molecular (Southern blot hybridization and reverse-transcription cleaved amplified polymorphic sequence analysis), genomic (analysis of variants) and cytogenetic (fluorescence in situ hybridization) approaches to study the structure, expression and epigenetic landscape of 35S rDNA in an allotetraploid grass that exhibits ND, Brachypodium hybridum (genome composition DDSS), and its putative progenitors, Brachypodium distachyon (DD) and Brachypodium stacei (SS). In progenitor genomes, B. stacei showed a higher intragenomic heterogeneity of rDNA compared with B. distachyon. In all studied accessions of B. hybridum, there was a reduction in the copy number of S homoeologues, which was accompanied by their inactive transcriptional status. The involvement of DNA methylation in CG and CHG contexts in the silencing of the S-genome rDNA loci was revealed. In the B. hybridum allotetraploid, ND is stabilized towards the D-genome units, irrespective of the polyphyletic origin of the species, and does not seem to be influenced by homoeologous 35S rDNA ratios and developmental stage. © 2020 The Authors. The Plant Journal published by Society for Experimental Biology and John Wiley & Sons Ltd.
Açıklama
Anahtar Kelimeler
35S rDNA evolution, 35S rRNA gene expression, allopolyploidy, Brachypodium hybridum, nucleolar dominance, Alkylation, Fluorescence microscopy, Plants (botany), RNA, Cleaved amplified polymorphic sequences, Developmental stage, Fluorescence in situ hybridization, Molecular mechanism, Nucleolar dominances, Polyphyletic origin, Reverse transcription, Southern blot hybridization, Transcription, Alkylation, Genes, Hybridization, Nucleic Acids, Ratios, Reduction, Set, Brachypodium, copy number variation, DNA methylation, gene locus, genetic polymorphism, genetics, metabolism, molecular evolution, plant chromosome, plant gene, plant genome, RNA gene, Southern blotting, tetraploidy, Blotting, Southern, Brachypodium, Chromosomes, Plant, DNA Copy Number Variations, DNA Methylation, Evolution, Molecular, Genes, Plant, Genes, rRNA, Genetic Loci, Genome, Plant, Polymorphism, Genetic, Tetraploidy
Kaynak
Plant Journal
WoS Q Değeri
Q1
Scopus Q Değeri
Q1
Cilt
103
Sayı
5
