Chromosome II Replication in Vibrio cholerae

Fatma Gözde Çilingir, Fabian Fredrich, Johannes Quintero & Gaye Tanrıöver

Studenteropgave: Semesterprojekt


Prokaryotes usually carry a single chromosome. There are also distinct DNA fragments called plasmids that have replication potential and a fixed copy number in each cell. , V.cholerae is an unusual species that carry second chromosome, which has smaller size than the main one. OriCIvc is an expression for the replication origin of V.cholerae main chromosome and OriCIIvc is for the replication origin of V.cholerae second chromosome. E.coli and V.cholerae are the members of γ-proteobacteria family, initiation mechanisms of the main chromosomes of the species are apparently similar, also the replication origins (OriC for E.coli, OriCIvc and OriCIIvc) share similar sequences. Since chromosome initiation mechanism of OriCI is well known, questions about initiation mechanisms on OriCIvc can also be replied. On the other hand, initiation of the second chromosome has a different mechanism. In order to find answers about replication mechanism of the second chromosomes, artificially built minichromosomes can be used. Minichromosome can be defined as origin of replication cloned on plasmids. Worthy to notify is that, minichromosomes do not have any fixed numbers in each cell and can be replicated only once in the cell cycle.2 In our experiment, by using DNA cloning methods i.e. plasmid DNA isolation, agarose gel electrophoresis, polymerase chain reaction (PCR) and some other microbiological methods i.e. transformation of electro competent cells etc. it was aimed to construct new minichromosomes manually and to observe the parameters affecting on copy number control, in other words, replication mechanisms. Further step of this experiment was designated as measuring the copy number distributions of minichromosomes by flow cytometric methods.

UddannelserMolekylærbiologi, (Bachelor/kandidatuddannelse) Bachelor el. kandidat
Udgivelsesdato20 jan. 2009


  • replication
  • minichromosome
  • Vibrio cholera