Naslov
Tandem repeat-containing MITEs in the clam Donax trunculus

Autori
Šatović, Eva ; Plohl, Miroslav

Izvornik
Genome biology and evolution (1759-6653) 5 (2013), 12; 2549-2559

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
mobile element; MITE; satellite DNA; tandem repeats; sequence rearrangements; evolution

Sažetak
Two distinct classes of repetitive sequences, interspersed mobile elements and satellite DNAs shape eukaryotic genomes and drive their volution. Short arrays of tandem repeats can also be present within non-autonomous miniature inverted repeat transposable elements (MITEs). In the clam Donax trunculus we characterized a composite, high-copy number MITE, named DTC84. It is composed of a central region built of up to five core repeats linked to a microsatellite segment at one array end, and flanked by sequences holding short inverted repeats. The modular composition and the conserved putative target-site duplication sequence AA at the element termini are equivalent to the composition of several elements found in the cupped oyster Crassostrea virginica and in some insects. A unique feature of D. trunculus element is ordered array of core repeat variants, distinctive by diagnostic changes. Position of variants in the array is fixed, regardless alterations in the core repeat copy number. Each repeat harbors a palindrome near the junction with the following unit, being a potential hotspot responsible for array length variations. As a consequence, variations in number of tandem repeats and variations in flanking sequences make every sequenced element unique. Core repeats may be thus considered as individual units within the MITE, with flanking sequences representing a “cassette” for internal repeats. Our results demonstrate that onset and spread of tandem repeats can be more intimately linked to processes of transposition than previously thought, and suggest that genomes are shaped by interplays within a complex network of repetitive sequences.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

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