Razlike u morfološkim i fiziološkim karakteristikama stanica kvasca Saccharomyces cerevisiae tijekom životnog vijeka

master's thesis

• Title (english): Morphological and physiological characteristics of the yeast Saccharomyces cerevisiae cells differing in the life span
• Author: Marina Kovačević
• Mentor: Lada Rumora (mentor)
• Committee member: Lada Rumora
• Committee member: Nada Vrkić
• Committee member: Olga Gornik
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of medical biochemistry and haematology); Zagreb
• Defense date and country: 2015-05-29, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Medical Biochemistry

Abstract

S. cerevisiae ima posebnu ulogu među modelnim organizmima u istraživanju starenja. Tijekom replikacijskog životnog vijeka stanice kvasca podliježu različitim promjenama. Cilj ovog istraživanja bio je promatranje morfoloških i fizioloških karakteristika na stanicama kvasca S. cerevisiae tijekom njegova replikacijskog životnog vijeka. Analizirane su tri genski različite skupine kvasca (SP4, BY4741 i BMA64-1A), od kojih svaka sadrži soj divljeg tipa te njegova dva mutanta (Δfob1 i Δsod1). Određene su stope staničnog rasta i utroška glukoze. Detekcija reaktivnih kisikovih radikala izvršena je pomoću testa s dihidroetidijem, dok su proteinske karbonilne skupine određene imunocitokemijski. Uzorci su također kultivirani kroz 7 dana, kako bi se fluorescentnim tehnikama utvrdile promjene u staničnoj morfologiji i metaboličkoj aktivnosti. Za interpretaciju parametrijskih rezultata korišteni su statistički testovi ANOVA. Rezultati istraživanja pokazali su da ne postoji značajna razlika u replikacijskom životnom vijeku između genskih skupina SP4 i BY4741, dok skupina sojeva BMA64-1A pokazuje veću osjetljivost na uvijete rasta. Divlji tip i mutant Δfob1 svake od genskih različitih skupina sojeva pokazuju manju osjetljivost na okolišne uvjete u odnosu na mutant Δsod1. Prema hipotezi da progresivno povećanje staničnog volumena tijekom replikacijskog životnog vijeka kvasca ograničava njegovu daljnju sposobnost diobe te rezultira starenjem, veličine stanica izmjerene u stacionarnoj fazi rasta bile su veće u odnosu na stanice u eksponencijalnoj fazi rasta.

Abstract (english)

S. cerevisiae has a special place among the model organisms currently in use for aging research. During their replicative lifespan yeast cells undergo age-related changes. The aim of this study was to observe morphological and physiological characteristics of the yeast S. cerevisiae cells during its replicative life span. Three different genetic background were analyzed (SP4, BY4741 and BMA64-1A), each consisting of a wild-type strain and its isogenic mutant (Δfob1 and Δsod1). Relative growth and rate of glucose consumption was determined as well as sensitivity to oxidative stress. Detection of the ROS was performed using dihydroethidium assay, while with the immunocytochemistry assay was determined the presence of protein carbonyl groups. Samples were also cultivated for 7 days, during which cellular alternations and metabolic activity were determined, both by corresponding fluorescence techniques. To interpret parametric results, ANOVA statistical tests were used. Results of experiments have shown that there is no significant difference in replicative life span between SP4 and BY4741 cells, whereas BMA64-1A cells showed higher sensitivity to growth conditions. Wild-type and Δfob1 strains of each genetic background demonstrated similar results in all experiments, showing the lower sensitivity to environmental conditions during the life span contrary to Δsod1 mutant. According to the hypothesis that reaching excessive volume by yeast cells limits their ability to undergo further reproduction resulting in cell senescence, stationary cells showed higher cell size than cells at exponential growth phase.

• Keywords: starenje; kvasac; S. cereviaise; životni vijek; replikacijski životni vijek
• Keywords (english): aging; yeast; S. cereviaise; life span; replicative life span
• Language: croatian
• URN:NBN: urn:nbn:hr:163:444555
• Study programme: Title: Medical Biochemistry; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra medicinske biokemije (magistar/magistra medicinske biokemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2016-02-16 11:53:36