Pokretni genetički elementi i rezistencija u bakterija

undergraduate thesis

• Title (english): Transposable genetic elements and antibiotic resistance in bacterias
• Author: Marina Martinić
• Mentor: Mirjana Kalafatić (mentor)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2009, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Varijabilnost je osnova evolucijskih promjena. Mutacije su osnova za nastanak varijabilnosti prokariota, no vrlo su rijetke, i jedna mutacija rezultira uglavnom promjenom jednog gena, te su stoga horizontalni prijenos gena i pokretni genetički elementi glavni čimbenici u evoluciji bakterijskih organizama. Cilj mi je stoga u ovome radu bio detaljno proučiti vrste pokretnih genetičkih elemenata koje nalazimo u bakterija, njihovu ulogu u nastanku rezistentnih oblika, te razmotriti potencijalna... More rješenja ovog problema. Razlikujemo tri vrste PGE: transpozone i dvije vrste retrotranspozona. Kod prokariotskih organizama nalazimo DNA transpozone koje s obzirom na složenost opet dijelimo u tri skupine: Insercijske sekvence (IS), složeni transpozoni i kompleksni transpozoni (transpozoni bez terminalnih IS-a). Insercijske sekvence nose samo gen a transpozazu, dok složeni i kompleksni transpozoni mogu nositi više gena, pa tako i gene za bakterijsku rezistenciju. Transpozicija je moguća na dva načina: (1) izravnim izrezivanjem i premještanjem na novo mjesto u genomu i (2) složenim replikativnim procesima prilikom kojih prvobitni transpozon ostaje na svome mjestu, a kopija se umeće na novo. Transpozoni se stoga mogu premještati s bakterijskog kromosoma na plazmid, s plazmida na bakteriokromosom i između plazmida, te pritom uzrokovati inverziju inserciju i deleciju ili napraviti višestruke kopije gena, što se danas smatra da je jedan od uzroka tj. načina nastanka R-plazmida. Da bi se u budućnosti mogli nositi s izazovima novih vrsta bakterijske rezistencije, nužno je dobro razumjeti i dalje proučavati mehanizme njihova nastanka, te funkciju svakog pojedinog gena uključenog u evoluciju R-oblika. Less

Abstract (english)

Variability is the key of evolutionary changes. Mutation is a basic source of variation within prokaryotic species, but mutations are rare, and usually only a single gene changes at one time, so horizontal gene transfer and transposable genetic elements (TGE, jumping genes) are the main factors in evolution of bacterial organisms. My goal was to study all the types of TGE in bacterial organisms, determine their role in creation of resistant forms, and discuss potential solutions for this... More problem. We can identify three sorts of TGE: transposons and two sorts of retrotransposons. In prokaryotic organisms, only DNA transposons appear, and we can again, considering their complexity, divide them into three main groups: Insertion sequences (IS), composite transposons and complex transposons. Insertion sequences carry only genes that code for protein transposase, while combined and complex transposons carry multiple genes, for instance: antimicrobial resistance genes. There are two modes of transposition: (1) direct transposition by cut-and-paste mechanism and (2) replicative transposition in which the original transposon remains in its site, and a copy is inserted at a target site. Thus, transposons can move from bacterial chromosome to plasmid (and wise versa), between plasmids, and during that, cause inversion, insertion and deletion, or create multiple copies of genes, which is today considered to be the cause for R-plasmid creation. In order to deal with challenges of new antimicrobial resistances, we must fully understand and continue to research mechanisms of their appearance, and function of every gene included in the evolution of R-forms. Less

• Keywords: pokretni genetički elementi; bakterije
• Keywords (english): transposable genetic elements; bacteria
• Language: croatian
• URN:NBN: urn:nbn:hr:217:883597
• Study programme: Title: Ecology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) biologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2018-03-13 12:40:36