Repetitive DNA Sequences

• Main Author: Dion-Côté, Anne-Marie (auth)
• Other Authors: Barbash, Daniel A. (auth), Clark, Andrew G. (auth), Lower, Sarah E. (auth)
• Format: Electronic Book Chapter
• Language: English
• Published: MDPI - Multidisciplinary Digital Publishing Institute 2020
• Subjects: Genetics (non-medical); transgene; zebra finch; transcription; endogenous retrovirus; transposable element; centromere drive; arthropods; PSR (Paternal sex ratio); Alu; gene evolution; nuclear rDNA; epigenetics; heterochromatin; alpha satellite; Su(Hw); repeated elements; karyotype; piRNA cluster; gene duplication; super-Mendelian; estrildidae; genomic conflict; GC-content; segregation; CENP-A; drift; germline; hobo; I element; repetitive DNA; transposons; human satellites; retrotransposons; genome assembly; LTR retrotransposons; satellite DNA; structural variation; selection; host genome; Uraeginthus cyanocephalus; LINE-1; B chromosomes; ERV; arms race; sequence variation; secondary structure; HeT-A and TART telomeric retrotransposons; database; genetic conflict; coevolution; ncRNAs (non coding RNAs); repeat; centromeric transcription; nucleolus; satellite; insulator; Rhino; population genetics; centromere; genome annotation; horizontal transfer; rRNA; genome elimination; genome evolution; evolution; chromosome evolution; genome size; genome; drosophila; transposable elements; selfish elements
• Online Access: DOAB: download the publication; DOAB: description of the publication

Repetitive DNA is ubiquitous in eukaryotic genomes, and, in many species, comprises the bulk of the genome. Repeats include transposable elements that can self-mobilize and disperse around the genome, and tandemly-repeated satellite DNAs that increase in copy number due to replication slippage and unequal crossing over. Despite their abundance, repetitive DNA is often ignored in genomic studies due to technical challenges in their identification, assembly, and quantification. New technologies and methods are now providing the unprecedented power to analyze repetitive DNAs across diverse taxa. Repetitive DNA is of particular interest because it can represent distinct modes of genome evolution. Some repetitive DNA forms essential genome structures, such as telomeres and centromeres, which are required for proper chromosome maintenance and segregation, whereas others form piRNA clusters that regulate transposable elements; thus, these elements are expected to evolve under purifying selection. In contrast, other repeats evolve selfishly and produce genetic conflicts with their host species that drive adaptive evolution of host defense systems. However, the majority of repeats likely accumulate in eukaryotes in the absence of selection due to mechanisms of transposition and unequal crossing over. Even these neutral repeats may indirectly influence genome evolution as they reach high abundance. In this Special Issue, the contributing authors explore these questions from a range of perspectives.