Utjecaj abiotičkog stresa na ukupnu genomsku i specifičnu metilaciju rDNA vrsta Quercus robur L. i Lilium bosniacum (Beck) Beck ex Fritsch

master's thesis

• Title (english): Effects of a biotic stress on level of global genome and specific rDNA methylation in Quercus robur (L.) and Lilium bosniacum (Beck) Beck ex Fritsch
• Author: Ivona Bečeheli
• Mentor: Vlatka Zoldoš (mentor)
• Committee member: Vlatka Zoldoš (predsjednik povjerenstva)
• Committee member: Mirjana Pavlica (član povjerenstva)
• Committee member: Goran Klobučar (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2011-05-23, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Biljke, kao sesilni organizmi koji ne mogu izbjeći stres, razvile su efikasne kratkoročne strategije za adaptaciju na promjene u okolišu koje se najviše odnose na brze promjene u ekspresiji gena putem epigenetičkih mehanizama. U ovom diplomskom radu istraživane su epigenetičke promjene u dvije vrste, hrastu lužnjaku i bosanskom ljiljanu, i to u populacijama trajno izloženim abiotičkom stresu uslijed promjena staništa. Upotrebom metode CRED-RA (Coupled Restriciton Enzyme Digestion-Random Amplification) analizirana je razina ukupne genomske metilacije DNA te metilacije specifičnog rDNA genomskog područja. U genomu bosanskog ljiljana, između stresne i kontrolne populacije, utvrđena je značajna razlika u učestalosti polimorfizama nastalih zbog metilacijskih događaja. Zbog izrazito visoke intra-populacijske genetičke varijabilnosti hrasta lužnjaka, metoda CRED-RA se pokazala nedovoljno preciznom za utvrđivanje metilacijskih događaja na populacijskoj razini. Metodom RAPD (Random Amplified Polymorphic DNA), utvrđen je veći broj polimorfizama DNA u genomu populacija izloženih stresu obiju istraživanih vrsta. Analiza specifične metilacije rDNA genomskog područja otkrila je hipermetiliranost rDNA sustava hrasta lužnjaka. Usporedbom CRED-RA obrasca specifične metilacije i restrikcijske mape za 18S-26S rRNA podjedinicu ove vrste pronađena su 4 hipometilirana mjesta unutar intergenske razmaknice čija je funkcija regulacija transkripcije ovih gena.

Abstract (english)

Plants, as sessile organisms that can not avoid stress, have developed an effective short-term strategies for adaptation to changes in the environment. These strategies imply rapid changes in gene expression through epigenetic mechanisms. This thesis deals with the study of epigenetic changes in genomes of two species, the common oak and Bosnian lily, growing in habitats continuously exposed to abiotic stress. The level of total genomic DNA methylation and methylation of rDNA region was analysed using method CRED-RA (Coupled Restriction Enzyme Digestion-Random Amplification). CRED-RA revealed statistically significant difference in methylation pattern between the population of Bosnian lily expossed to stres and the control population. Due to extremely high intra-population genetic diversity of the common oak, CRED-RA method proved to be insufficiently precise to determine methylation events on population level. A higher frequency of RAPD polymorphisms was recorded in populations exposed to stress comparing to control populations of both species. Analysis of specific rDNA methylation revealed hypermethylation of coding regions and hypomethylation of intergenic region of oak rDNA. Comparing the CRED-RA pattern and restriction maps for 18S-26S rRNA subunit of this species, 4 hypomethylated loci were found within the intergenic spacer, which implies on the possible role in regulation of rRNA gene transcription.

• Keywords: CRED-RA; IGS; metilacija; polimorfizam; RAPD
• Keywords (english): CRED-RA; IGS; methylation; polymorphism; RAPD
• Language: croatian
• URN:NBN: urn:nbn:hr:217:537359
• Study programme: Title: Molecular Biology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra molekularne biologije (magistar/magistra molekularne biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-05-02 12:40:50