Naslov
What a difference "junk" DNAs make

Autori
Mravinac, B ; Ugarković, Đ ; Plohl, M

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

Izvornik
Embo Workshop 2005 - Chromosome structural elements: from DNA sequence to function / Ascenzioni, Fiorentina - Rim : Casa Editrice Universita degli Studi di Roma "La Sapienza", 2005

Skup
Embo Workshop 2005 - Chromosome structural elements: from DNA sequence to function

Mjesto i datum
Rim, Italija, 29.09.2005. - 03.10.2005

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
satellite DNA; Tenebrionidae; concerted evolution; speciation

Sažetak
Satellite DNAs (stDNAs) are highly abundant sequences, tandemly repeated in the centromeric/telomeric heterochromatin. Since no unambiguous function was assigned to them, they were proclaimed to be a useless "junk" DNA for decades. Analyzing stDNAs of the beetle Tribolium audax, we discovered two repetitive families. TAUD1 is a typical centromeric stDNA, composed of a 112 bp repetitive unit, which comprises 40% of the genome. 19% of the genome belongs to the TAUD2 sequences, which are interspersed sporadically among the arrays of tandemly repeated TAUD1 units. The complex TAUD2 sequence, 1412 bp long, consists of the two unusually long inverted segments which could provoke formation of a thermodynamically stable dyad structure that might considerably contribute to the compact state and stability of the centromeric heterochromatin. Interestingly, the TAUD1 repetitive unit is recognized as a building element of the TAUD2 family. Even more surprisingly, the TAUD1 and TAUD2 repetitive families show remarkable similarity to the stDNAs detected in the centromeric regions of the sibling species T. madens. Despite differences in nucleotide sequence and substructure of repetitive units, the stDNAs of the two siblings derived undoubtedly from a common ancestral satellite family. Concerning the portion of genome that these "junk" DNAs comprise, an acquisition of changes in stDNAs could result in genetically reproductive barriers, leading thus to the speciation. In other words, it is highly probable that stDNAs played a role in the evolutionary separation of T. audax and T. madens.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

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