Naslov
Genetic instability of closely spaced invarted repeats in the genome of Saccharomyces cerevisiae

Autori
Miklenić, Marina ; Lisnić, Berislav ; Žunar, Bojan ; Svetec, Ivan-Krešimir

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

Skup
3rd Congress of Croatian Geneticists with international participation

Mjesto i datum
Krk, Hrvatska, 13.05.2012. - 16.05.2012

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
palindromes; inverted repeats; genetic instability; yeast
(palindromes; inverted repeats; genetic instability; yeas)

Sažetak
Inverted repeats and palindromes (inverted repeats with no spacer DNA between the repeats) are sequences which can be found in genomes of all organisms. They are notorious for their ability to provoke genome instability, e.g. deletions, translocations and amplifications. One example of such instability is the recurrent translocation between chromosomes 11 and 22 in the human genome caused by palindromes and resulting in Emmanuel syndrome characterised by physical malformations and mental retardation. The instability of inverted repeats and palindromes is attributed to their ability to undergo intrastrand basepairing and form secondary DNA structures – hairpins and cruciforms - which lead to double strand breaks and present obstacles during DNA replication. Genetic instability of inverted repeats increases with the length of repeats and decreases with the distance between them. Previously, we investigated the influence of palindrome length on genetic instability using yeast Saccharomyces cerevisiae as model organism. We determined that palindromes longer than 70 bp become increasingly unstable and present a risk for genome stability. Here, we present the results of analysis of instability of two 63 bp long inverted repeats depending on the distance between them (ranging from 0 bp, 1 bp, ..., up to 10 bp). Results show that inverted repeats spaced by 0 bp (126 bp palindrome) to 5 bp are highly unstable. However, spacer of only 6 bp is sufficient to increase the stability of the inverted repeats, while spacer of 10 bp completely stabilises the repeats. These results, combined with our insight on relationship between the length of the repeats and their instability, can help us determine which sequences present in the genome are a risk for its stability. Also, these results emphasize the strong influence of sequence at the axis of symmetry on the dynamics of cruciform formation and/or its stability once it forms.

Izvorni jezik
Engleski

Znanstvena područja
Biotehnologija

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