Naslov
TCAGG, an alternative telomeric sequence in insects

Autori
Mravinac, Brankica ; Meštrović, Nevenka ; Čavrak, Vladimir Vanja ; Plohl, Miroslav

Izvornik
Chromosoma (Berlin) (0009-5915) 120 (2011), 4; 367-376

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

Ključne riječi
telomere; telomeric DNA; TCAGG; TTAGG; insects; Coleoptera

Sažetak
The TTAGG repeat, the only determined telomerase-dependent sequence in the Insecta, is generally reputed to be the canonical telomeric motif within the class. By studying the distribution of telomeric DNAs in 30 coleopteran beetles using Southern hybridization, BAL 31 DNA end-degradation assay and fluorescence in situ hybridization, we showed that arrays built of a TCAGG repeat substitute for (TTAGG)n sequences in all tested species within the superfamily Tenebrionoidea. We also provided the experimental evidence that (TCAGG)n repeats represent the terminal sequences on all chromosomes of the model species Tribolium castaneum. (TCAGG)n repeats are therefore promoted as the first sequence-motif alternative to TTAGG-type chromosome ends in insects. Detection of species negative for both TTAGG and TCAGG reveals that, although widespread, these motifs are not ubiquitous telomeric sequences within the order Coleoptera. In addition, Timarcha balearica proved to be a species that harbors (TTAGG)n repeats, but not at telomeric positions, thus further increasing the complexity of telomeric DNAs. Our experiments discarded CTAGG, CTGGG, TTGGG, and TTAGGG variants as potential replacements in TTAGG/TCAGG negative species, indicating that chromosome termini of these beetles comprise other form(s) of telomeric sequences and telomere-maintenance mechanisms.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

POVEZANOST RADA