Two-dimensional RFLP analyses reveal megabase-sized clusters of rRNA gene variants in Arabidopsis thaliana, suggesting local spreading of variants as the mode for gene homogenization during concerted evolution - PubMed (original) (raw)

Comparative Study

Two-dimensional RFLP analyses reveal megabase-sized clusters of rRNA gene variants in Arabidopsis thaliana, suggesting local spreading of variants as the mode for gene homogenization during concerted evolution

G P Copenhaver et al. Plant J. 1996 Feb.

Free article

Abstract

Eukaryotic genes encoding the precursor of 18S, 5.8S and 25S ribosomal RNA (rRNA genes or rDNA) are virtually identical within a species, yet they evolve rapidly between species, a phenomenon known as concerted evolution. The mechanisms by which sequence homogenization and fixation of new rRNA gene variants occurs within a genome are not clear. In diploid Arabidopsis thaliana, approximately 1500 rRNA genes are tandemly arrayed at two nucleolus organizer regions, one on chromosome 2 (NOR2), the other on chromosome 4 (NOR4). This paper shows that NOR2 and NOR4 are similar in size, each spanning approximately 3.5-4.0 Mbp. Using two-dimensional mapping techniques involving a combination of pulsed-field and conventional gel electrophoresis, the distributions of four distinct rRNA gene variants at NOR2 and NOR4 have been determined. rRNA genes at NOR4 are homogeneous with respect to a HindIII site occurring once per gene. In contrast, fewer than 10% of the rRNA genes at NOR2 are HindIII-bearing variants. A single intergenic spacer length is found among rRNA genes at NOR2 but three classes of spacer length variants are present at NOR4. The NOR4 variants are not intermingled with one another; instead, they are highly clustered over distances as large as 1.5 Mbp. These data suggest that in the concerted evolution of rRNA genes, homogenization is a consequence of local spreading of new rRNA gene variants.

PubMed Disclaimer

Cited by

Chromosome-level genome assemblies reveal genome evolution of an invasive plant Phragmites australis.
Wang C, Liu L, Yin M, Liu B, Wu Y, Eller F, Gao Y, Brix H, Wang T, Guo W, Salojärvi J. Wang C, et al. Commun Biol. 2024 Aug 17;7(1):1007. doi: 10.1038/s42003-024-06660-1. Commun Biol. 2024. PMID: 39154094 Free PMC article.
Transcriptional Silencing of 35S rDNA in Tragopogon porrifolius Correlates with Cytosine Methylation in Sequence-Specific Manner.
Matyášek R, Kalfusová R, Kuderová A, Řehůřková K, Sochorová J, Kovařík A. Matyášek R, et al. Int J Mol Sci. 2024 Jul 9;25(14):7540. doi: 10.3390/ijms25147540. Int J Mol Sci. 2024. PMID: 39062783 Free PMC article.
The MBD-ACD DNA methylation reader complex recruits MICRORCHIDIA6 to regulate ribosomal RNA gene expression in Arabidopsis.
Ren Z, Gou R, Zhuo W, Chen Z, Yin X, Cao Y, Wang Y, Mi Y, Liu Y, Wang Y, Fan LM, Deng XW, Qian W. Ren Z, et al. Plant Cell. 2024 Mar 29;36(4):1098-1118. doi: 10.1093/plcell/koad313. Plant Cell. 2024. PMID: 38092516
Sequence and epigenetic landscapes of active and silent nucleolus organizer regions in Arabidopsis.
Fultz D, McKinlay A, Enganti R, Pikaard CS. Fultz D, et al. Sci Adv. 2023 Nov 3;9(44):eadj4509. doi: 10.1126/sciadv.adj4509. Epub 2023 Nov 1. Sci Adv. 2023. PMID: 37910609 Free PMC article.
Arabidopsis ASYMMETRIC LEAVES2 and Nucleolar Factors Are Coordinately Involved in the Perinucleolar Patterning of AS2 Bodies and Leaf Development.
Ando S, Nomoto M, Iwakawa H, Vial-Pradel S, Luo L, Sasabe M, Ohbayashi I, Yamamoto KT, Tada Y, Sugiyama M, Machida Y, Kojima S, Machida C. Ando S, et al. Plants (Basel). 2023 Oct 19;12(20):3621. doi: 10.3390/plants12203621. Plants (Basel). 2023. PMID: 37896084 Free PMC article.

Two-dimensional RFLP analyses reveal megabase-sized clusters of rRNA gene variants in Arabidopsis thaliana, suggesting local spreading of variants as the mode for gene homogenization during concerted evolution - PubMed (original) (raw)