Konformační vlastnosti mikrosatelitu (CGG) souvisejícího se syndromem fragilního chromosomu X přerušeného tripletem (AGG)

Mgr. Tereza Valachová

Bachelor's thesis

Abstract:

Tato prace se zabyvy studiem konformacnich vlastnosti mikrosatelitu (CGG) souvisejiciho se syndromem fragilniho chromosomu X. Tento syndrom je jednou z nejcastjsich pricin vrozene mentalni retardace. Postizeni jedinci maji mnohonasobne zvyseny pocet opakovani mikrosatelitu (CGG) na 5 konci neprekladaneho useku genu FMR-1. U zdravych jedincu je priblizne kazde desate opakovani (CGG) preruseno trinukleotidem (AGG). Pomocí CD spektroskopie, UV absorpcní spektroskopie a elektroforetickych metod byly studovany konformacni vlastnosti syntetickych polynukleotidu, ktere byly tvoreny presne danym poctem opakovani tripletu (CGG), prerusenych v ruznych mistech trinukleotidem (AGG). Byl zkouman predevsim vliv teploty, pH a iontu na strukturu a stabilitu motivu. Bylo zjisteno, ze strukturou, která je zodpovedna za prodluzování dane oblasti genu, je zrejme vlasenka a ne tetraplex, jak bylo navrzeno drive.

Abstract:

This thesis is concerned with conformational properties of the (CGG)n microsatellite, which is connected with the fragile X chromosome syndrome. This syndrome is the most common form of an inherited mental retardation in humans and is associated with the expansion of the (CGG) trinucleotide repeat in the 5- untranslated region of the FMR1 gene. In the healthy individuals, about every ten repeats are interrupted by an AGG triplet. Conformational properties of synthetic polynucleotides, formed by a definite number of (CGG) repeats interrupted by (AGG) at different places, were studied by means of circular dichroism spectroscopy, UV absorption spectroscopy, and electrophoretic methods. It was examined how temperature, pH and ions influenced the arrangement and stability of this motif. It was shown that the probable structure responsible for the repeat expansion in genomes is a hairpin, not a tetraplex, as had been suggested before.

Keywords

DNA, syndrom fragilniho chromozómu X, guaninove baze, trinukleotid (CGG), trinukleotid (AGG), cirkularni dichroismus, UV absorpcní spektroskopie, polyakrylamidová elektroforeza, tetraplex, vlasenka DNA, fragile X chromosome syndrom, guanin base, trinucleotide (CGG), trinucleotide (AGG), circular dichroism, UV absorption spectroscopy, polyacrylamide electrophoresis, quadruplex, hairpin

Language used: Czech

Date on which the thesis was submitted / produced: 29. 5. 2006

Thesis defence

• Date of defence: 27. 6. 2006
• Supervisor: prof. RNDr. Michaela Vorlíčková, DrSc.

Masaryk University

Faculty of Science

Bachelor programme / field:
Physics / Biophysics