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undergraduate thesis
Zaustavljanje staničnog ciklusa u oskudnim uvjetima u bakteriji Escherichia coli
Zagreb: University of Zagreb, Faculty of Science, 2012. urn:nbn:hr:217:389620
Berečić, Branimir
University of Zagreb
Faculty of Science
Department of Biology

Institutional repository: Repository of the Faculty of Science

Cite this document

Berečić, B. (2012). Zaustavljanje staničnog ciklusa u oskudnim uvjetima u bakteriji Escherichia coli (Undergraduate thesis). Zagreb: University of Zagreb, Faculty of Science. Retrieved from https://urn.nsk.hr/urn:nbn:hr:217:389620

Berečić, Branimir. "Zaustavljanje staničnog ciklusa u oskudnim uvjetima u bakteriji Escherichia coli." Undergraduate thesis, University of Zagreb, Faculty of Science, 2012. https://urn.nsk.hr/urn:nbn:hr:217:389620

Berečić, Branimir. "Zaustavljanje staničnog ciklusa u oskudnim uvjetima u bakteriji Escherichia coli." Undergraduate thesis, University of Zagreb, Faculty of Science, 2012. https://urn.nsk.hr/urn:nbn:hr:217:389620

Berečić, B. (2012). 'Zaustavljanje staničnog ciklusa u oskudnim uvjetima u bakteriji Escherichia coli', Undergraduate thesis, University of Zagreb, Faculty of Science, accessed 25 November 2024, https://urn.nsk.hr/urn:nbn:hr:217:389620

Berečić B. Zaustavljanje staničnog ciklusa u oskudnim uvjetima u bakteriji Escherichia coli [Undergraduate thesis]. Zagreb: University of Zagreb, Faculty of Science; 2012 [cited 2024 November 25] Available at: https://urn.nsk.hr/urn:nbn:hr:217:389620

B. Berečić, "Zaustavljanje staničnog ciklusa u oskudnim uvjetima u bakteriji Escherichia coli", Undergraduate thesis, University of Zagreb, Faculty of Science, Zagreb, 2012. Available at: https://urn.nsk.hr/urn:nbn:hr:217:389620

Metadata
TitleZaustavljanje staničnog ciklusa u oskudnim uvjetima u bakteriji Escherichia coli
Title (english)The stringent response and cell cycle arrest in Escherichia coli
AuthorBranimir Berečić
MentorIvana Ivančić Baće (mentor)
GranterUniversity of Zagreb
Faculty of Science
(Department of Biology)
Zagreb
Defense date and country2012, Croatia
Scientific / art field,
discipline and subdiscipline		NATURAL SCIENCES
Biology
Abstract
Bakterijski "stringent response", uzrokovan nedostatkom hranjivih tvari, potiče gomilanje signalnih nukleotida ppGpp i pppGpp. Stanice divljeg tipa prolaze kroz zastoj ovisan o proteinu RelA nakon što ih se tretira serin hidroksamatom kako bi imale cijeli broj kromosoma u sebi i omjer ishodišta/terminacijskih slijedova 1. Stanje rasta prije nestašice hranjivih tvari određuje broj kromosoma u stanici nakon zastoja staničnog ciklusa; regije kromosoma u kojima se nalaze ishodišta replikacije su razdvojene, ali regije sa terminacijskim slijedovima su sparene. Nukleoidi u takvim "zaustavljenim" bakterijama su nekondenzirani. Ukoliko se stanice tretiraju kloramfenikolom nukleoidi postaju vrlo kondenzirani, a tretiranjem rifampicinom i cefaleksinom kromosomi više nisu spareni kod terminacijskih slijedova. Stvaranje kolonija je inhibirano zbog nakupljanja ppGpp, osim u mutantima ΔseqA i Δdam. Završetak gladovanja dovodi do vrlo brze reorganizacije nukleoida, razdvajanja kromosoma i dovršavanja replikacije. Osim nakupljanja ppGpp, metilacija DNA i vezanje SeqA su čimbenici potrebni za pokretanje potpunog zastoja u stanici, čime se utjecalo na inicijaciju replikacije i segregaciju kromosoma.
Abstract (english)
The bacterial stringent response, triggered by nutritional deprivation, causes an accumulation of the signaling nucleotides ppGpp and pppGpp. Wild type cells undergo a RelA-dependent arrest after treatment with serin hydroxamage in order to contain an integer number of chromosomes and a replication origin/terminus ratio of 1. The growth rate prior to starvation determines the number of chromosomes after arrest; chromosomal regions corresponding to the origins of replication are segregated, while the termination regions remain colocalized. Nucleoids of these arrested cells are decondensed. If treated with chloramphenicol, they become highly condensed, and treatment with rifampicin and cephalexin causes the chromosomes to segregate at their termination regions. Colony formation is inhibited due to ppGpp accumulation, except in ΔseqA and Δdam mutants. Release from starvation causes rapid nucleoid reorganization, chromosome segregation and replication resumption. Accumulation of nucleotid ppGpp, DNA methilation and SeqA binding are all factors which contribute to initiating complete cell cycle arrest, which in turn affects replication initiation and chromosome segregation.
Keywords
Keywords (english)
Languagecroatian
URN:NBNurn:nbn:hr:217:389620
Study programmeTitle: 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 resourceText
File originBorn digital
Access conditionsOpen access
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Created on2018-04-12 11:13:56