caa a22 4500 606190430 CHVBK 20210128100855.0 cr unu---uuuuu 210128e20150901xx s 000 0 eng 10.1007/s10577-015-9499-z doi (NATIONALLICENCE)springer-10.1007/s10577-015-9499-z Repetitive DNA in eukaryotic genomes [Elektronische Daten] [Maria Biscotti, Ettore Olmo, J. Heslop-Harrison] Repetitive DNA—sequence motifs repeated hundreds or thousands of times in the genome—makes up the major proportion of all the nuclear DNA in most eukaryotic genomes. However, the significance of repetitive DNA in the genome is not completely understood, and it has been considered to have both structural and functional roles, or perhaps even no essential role. High-throughput DNA sequencing reveals huge numbers of repetitive sequences. Most bioinformatic studies focus on low-copy DNA including genes, and hence, the analyses collapse repeats in assemblies presenting only one or a few copies, often masking out and ignoring them in both DNA and RNA read data. Chromosomal studies are proving vital to examine the distribution and evolution of sequences because of the challenges of analysis of sequence data. Many questions are open about the origin, evolutionary mode and functions that repetitive sequences might have in the genome. Some, the satellite DNAs, are present in long arrays of similar motifs at a small number of sites, while others, particularly the transposable elements (DNA transposons and retrotranposons), are dispersed over regions of the genome; in both cases, sequence motifs may be located at relatively specific chromosome domains such as centromeres or subtelomeric regions. Here, we overview a range of works involving detailed characterization of the nature of all types of repetitive sequences, in particular their organization, abundance, chromosome localization, variation in sequence within and between chromosomes, and, importantly, the investigation of their transcription or expression activity. Comparison of the nature and locations of sequences between more, and less, related species is providing extensive information about their evolution and amplification. Some repetitive sequences are extremely well conserved between species, while others are among the most variable, defining differences between even closely relative species. These data suggest contrasting modes of evolution of repetitive DNA of different types, including selfish sequences that propagate themselves and may even be transferred horizontally between species rather than by descent, through to sequences that have a tendency to amplification because of their sequence motifs, to those that have structural significance because of their bulk rather than precise sequence. Functional consequences of repeats include generation of variability by movement and insertion in the genome (giving useful genetic markers), the definition of centromeres, expression under stress conditions and regulation of gene expression via RNA moieties. Molecular cytogenetics and bioinformatic studies in a comparative context are now enabling understanding of the nature and behaviour of this major genomic component. Springer Science+Business Media Dordrecht, 2015 Repetitive DNA nationallicence Tandem repeats nationallicence Genomics nationallicence Junk DNA nationallicence Transposons nationallicence Satellite DNA nationallicence Retrotransposons nationallicence Review nationallicence GC : guanine-cytosine content nationallicence miRNA : microRNA nationallicence ncRNA : Non coding RNA nationallicence NOR : Nucleolar organizing region nationallicence rDNA : ribosomal DNA nationallicence satDNA : Satellite DNA nationallicence TE : Transposable element nationallicence Biscotti Maria Dipartimento di Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, 60131, Ancona, Italy aut Olmo Ettore Dipartimento di Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, 60131, Ancona, Italy aut Heslop-Harrison J. Department of Genetics, University of Leicester, LE1 7RH, Leicester, UK aut Chromosome Research Springer Netherlands 23/3(2015-09-01), 415-420 0967-3849 23:3<415 2015 23 10577 https://doi.org/10.1007/s10577-015-9499-z text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10577-015-9499-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Biscotti Maria Dipartimento di Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, 60131, Ancona, Italy aut NATIONALLICENCE 700 1- Olmo Ettore Dipartimento di Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, 60131, Ancona, Italy aut NATIONALLICENCE 700 1- Heslop-Harrison J. Department of Genetics, University of Leicester, LE1 7RH, Leicester, UK aut NATIONALLICENCE 773 0- Chromosome Research Springer Netherlands 23/3(2015-09-01), 415-420 0967-3849 23:3<415 2015 23 10577