Naslov
Organization and evolution of Tribolium madens (Insecta, Coleoptera) satellite DNA

Autori
Durajlija-Žinić, Sonja ; Plohl, Miroslav ; Ugarković, Đurđica

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

Izvornik
Svečani sastanak hrvatskih biokemičara uz 20. obljetnicu osnutka društva : knjiga sažetaka = 20th Anniversary Meeting of Croatian Biochemical Society : abstracts / Kućan, Željko ; Barišić, Karmela ; Flögl, Mirna ; Lauc, Gordan ; Lenhard, Boris ; Weygand-Đurašević, Ivana - Zagreb : Farmaceutsko-biokemijski fakultet Sveučilišta u Zagrebu, 1996, 82-82

ISBN
953-6256-19-3

Skup
Svečani sastanak hrvatskih biokemičara uz 20. obljetnicu osnutka društva

Mjesto i datum
Zagreb, Hrvatska, 18.10.1996. - 19.10.1996

Vrsta sudjelovanja
Poster

Vrsta recenzije
Domaća recenzija

Ključne riječi
Satellite DNA, heterochromatin, evolution, Tribolium madens, in situ hybridization, pulsed-field gel electrophoresis

Sažetak
Two different satellite DNAs from tenebrionid species Tribolium madens (Insecta ; Coleoptera) have been detected, cloned and sequenced. Satellite I comprises 30% of the genome ; it has a monomer size of 225 bp and a high A+T content of 74%. Satellite II with a monomer size of 711 bp and A+T content of 70%, is less abundant, making 4% of the total DNA. Both satellites are localised in the heterochromatic regions of all chromosomes, as revealed by in situ hybridisation. A search for internal motifs showed that both satellites contain a related subsequences, about 100 bp long. The creation of satellite I is explained by duplication of basic subunit, followed by subsequent divergence by single point mutations, deletions and gene conversion. Inversion of the subsequence in addition to its duplication has occurred in satellite II. The result of this inversion is possible of a long stable dyad structure. The 408-bp sequence, inserted within satellite II monomer, shares no similarity with a basic subunit. Frequent direct repeats found within the inserted sequence point to its evolution by duplication of shorter motifs. it is proposed that both satellites have been derived from a common ancestral sequence whose duplication played a major role in the formation of satellite I monomer, while insertion of a new sequence together with inversion of an ancestral one induced the occurrence of satellite II. Pulsed-field gel electrophoresis followed by subsequent Souther hybridisation analysis of T. maidens satellites I and II, revealed their organization in clusters of varying length, ranging in size from 50 kb to more than 2 Mb. Comparison between the hybridisation patterns of two satellite repeats revealed their existence in separate domains within the same centromeric array. Data obtained using hybridisation conditions of different stringencies point to further subdivision of satellite I and satellite II domains to separate subfamily-specific clusters.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

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