Naslov
Satellite DNA sequences of three species from the genus Tribolium (Insecta, Coleoptera)

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

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
1st Croatian Congress on Molecular Life Sciences, Book of Abstracts / Dumić, Jerka - Zagreb : Farmaceutsko-biokemijski fakultet Sveučilišta u Zagrebu, 2002, 104-104

Skup
1st Croatian Congress on Molecular Life Sciences

Mjesto i datum
Opatija, Hrvatska, 09.06.2002. - 13.06.2002

Vrsta sudjelovanja
Poster

Vrsta recenzije
Domaća recenzija

Ključne riječi
satellite DNA; heterochromatin; Tribolium

Sažetak
The genomes of the three tenebrionid beetles Tribolium brevicornis, T. anaphe, and T. destructor have been examined in order to ascertain highly repetitive DNA sequences. The TBREV, TANAPH, and TDEST satellites have been identified as the major satellite DNAs of the mentioned species, respectively. Cloning and sequencing results have demonstrated that the three satellites differ significantly in the length of their repeating units (1061 bp, 161 bp, and 145 bp, respectively). Furthermore, the TBREV, TANAPH, and TDEST satellite constitute 21.2%, 13.2%, and 0.7% of the corresponding genomic DNAs. Despite the striking differences in the monomer unit length and the portion in the genomes, the three Tribolium satellites have several features in common: a low intraspecific sequence variation ranging from 1.1% to 2.7%, predominantly due to random distribution of point mutations ; a high A+T content (68.9-79.3%), abundant in A/T stretches ; the presence of direct and inverted repeats potentially able to form dyad structures ; the localization in the regions of pericentromeric heterochromatin of all 18 chromosomes, as evidenced by fluorescent in situ hybridization. Analysis of internal sequence organization has revealed that the TANAPH and TDEST monomers represent unique sequences without any noticeable subunits, whereas the TBREV satellite is composed of two unusually long inverted repeats of ~450 bp, separated by two short regions. Such an intriguing structure of the monomer is explained by duplication and subsequent inversion of the basic unit, resulting in the possible formation of a long, thermodynamically stable dyad structure. Concerning the research of satellite structure complexity, organization, and evolution, species from the genus Tribolium appear to be a very suitable experimental model. The novel repetitive sequences analyzed in this study will be compared with previously described Tribolium satellites, in an attempt to advance our understanding of molecular mechanisms and evolutionary processes acting on satellite sequences of this genus.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

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