PT  - JOURNAL ARTICLE
AU  - Martina Dalíková
AU  - Irena Provazníková
AU  - Jan Provazník
AU  - Patrick Grof-Tisza
AU  - Adam Pepi
AU  - Petr Nguyen
TI  - The role of repetitive DNA in re-patterning of major rDNA clusters in Lepidoptera
AID  - 10.1101/2022.03.26.485928
DP  - 2022 Jan 01
TA  - bioRxiv
PG  - 2022.03.26.485928
4099  - http://biorxiv.org/content/early/2022/03/27/2022.03.26.485928.short
4100  - http://biorxiv.org/content/early/2022/03/27/2022.03.26.485928.full
AB  - Genes for major ribosomal RNAs (rDNA) are present in multiple copies organized in tandem arrays. Number and position of rDNA loci can change dynamically and their re-patterning is presumably driven by repetitive sequences. We explored a peculiar rDNA organization in several representatives of Lepidoptera with either extremely large or numerous rDNA clusters. We combined molecular cytogenetics with analyses of second and third generation sequencing data to show that rDNA spreads as a transcription unit and reveal association between rDNA and various repeats. Furthermore, we performed comparative long read analyses between the species with derived rDNA distribution and moths with a single rDNA locus, which is considered ancestral. Our results suggest that satellite arrays, rather than mobile elements, facilitate homology-mediated spread of rDNA via either integration of extrachromosomal rDNA circles or ectopic recombination. The latter arguably better explains preferential spread of rDNA into terminal regions of lepidopteran chromosomes as efficiency of ectopic recombination depends on proximity of homologous sequences to telomeres.Competing Interest StatementThe authors have declared no competing interest.