Naslov
Preservation and high sequence conservation of satellite DNAs suggest functional constraints

Autori
Mravinac, Brankica ; Plohl, Miroslav ; Ugarković, Đurđica

Izvornik
Journal of Molecular Evolution (0022-2844) 61 (2005), 4; 542-550

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

Ključne riječi
satellite DNA evolution ; Coleoptera ; Insecta ; repetitive DNA ; heterochromatin ; selective pressure

Sažetak
Due to a high evolutionary turnover many satellite DNAs are restricted to a group of closely related species. Here we demonstrate that satellite DNA family PSUB, abundant in beetle Palorus subdepressus, is distributed in low number of copies among diverse taxa of Coleoptera (Insecta), some of them separated for evolutionary period of up to 60 Myr. Comparison of PSUB cloned from species Tribolium brevicornis with PSUB family previously characterized in Palorus subdepressus, revealed no sequence divergence including complete absence of fixed species specific mutations. The most polymorphic sites are those with ancestral mutations shared among clones of both species. Since the ancestral mutations contribute significantly to the overall diversity it could be proposed that a similar mutational profile already existed in an ancestral species. The pattern of variability along the satellite monomer is characterized by the presence of conserved and variable regions. The non-random pattern of variability as well as absence of sequence divergence is also discerned for PRAT satellite DNA, cloned previously from two Palorus species and distantly related Pimelia elevata. Since PRAT and PSUB are present in parallel in diverse taxa of Coleoptera we propose that their long evolutionary preservation suggests possible functional significance. This indication is additionally supported not only by high evolutionary conservation of the sequences and their mutational profiles, but also by the presence of significantly conserved and variable regions along the monomers.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

POVEZANOST RADA