Publication details

Uniparental silencing of 5S rRNA genes in plant allopolyploids - insights from <i>Cardamine</i> (Brassicaceae)

Investor logo
Authors

MALÍK MANDÁKOVÁ Terezie KRUMPOLCOVÁ Alice MATYÁŠEK Roman VOLKOV Roman LYSÁK Martin KOVARIK Ales

Year of publication 2024
Type Article in Periodical
Magazine / Source Plant Journal
MU Faculty or unit

Central European Institute of Technology

Citation
Web https://onlinelibrary.wiley.com/doi/10.1111/tpj.16850
Doi http://dx.doi.org/10.1111/tpj.16850
Keywords rRNA genes; 5S rDNA; 35S rDNA; Cardamine; polyploidy; gene silencing; chromosome evolution
Attached files
Description While the phenomenon of uniparental silencing of 35S rDNA in interspecific hybrids and allopolyploids is well documented, there is a notable absence of information regarding whether such silencing extends to the 5S RNA component of ribosomes. To address this gap in knowledge, we analyzed the 5S and 35S rDNA expression in Cardamine (Brassicaceae) allopolyploids, namely C. x insueta (2n = 3x = 24, genome composition RRA), C. flexuosa (2n = 4x = 32, AAHH), and C. scutata (2n = 4x = 32, PPAA) which share a common diploid ancestor (AA). We employed high-throughput sequencing of transcriptomes and genomes and phylogenetic analyses of 5S rRNA variants. The genomic organization of rDNA was further scrutinized through clustering and fluorescence in situ hybridization. In the C. x insueta allotriploid, we observed uniparental dominant expression of 5S and 35S rDNA loci. In the C. flexuosa and C. scutata allotetraploids, the expression pattern differed, with the 35S rDNA being expressed from the A subgenome, whereas the 5S rDNA was expressed from the partner subgenome. Both C. flexuosa and C. scutata but not C. x insueta showed copy and locus number changes. We conclude that in stabilized allopolyploids, transcription of ribosomal RNA components occurs from different subgenomes. This phenomenon appears to result in the formation of chimeric ribosomes comprising rRNA molecules derived from distinct parental origins. We speculate that the interplay of epigenetic silencing and rDNA rearrangements introduces an additional layer of variation in multimolecule ribosomal complexes, potentially contributing to the evolutionary success of allopolyploids.
Related projects:

You are running an old browser version. We recommend updating your browser to its latest version.

More info