Segregation of chromosome arms in growing and non-growing Escherichia coli cells
In slow-growing Escherichia coli cells the chromosome is organized with its left (L) and right (R) arms lying separated in opposite halves of the nucleoid and with the origin (O) in-between, giving the pattern L-O-R. During replication one of the arms has to pass the other to obtain the same organiz...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2015-05-01
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| Series: | Frontiers in Microbiology |
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| Online Access: | http://journal.frontiersin.org/Journal/10.3389/fmicb.2015.00448/full |
| _version_ | 1819078402268725248 |
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| author | Conrad L. Woldringh Flemming G. Hansen Norbert O.E. Vischer Tove eAtlung |
| author_facet | Conrad L. Woldringh Flemming G. Hansen Norbert O.E. Vischer Tove eAtlung |
| author_sort | Conrad L. Woldringh |
| collection | DOAJ |
| description | In slow-growing Escherichia coli cells the chromosome is organized with its left (L) and right (R) arms lying separated in opposite halves of the nucleoid and with the origin (O) in-between, giving the pattern L-O-R. During replication one of the arms has to pass the other to obtain the same organization in the daughter cells: L-O-R L-O-R. To determine the movement of arms during segregation six strains were constructed carrying three coloured loci: the left and right arms were labeled with red and cyan fluorescent-proteins, respectively, on loci symmetrically positioned at different distances from the central origin, which was labeled with green-fluorescent protein. In non-replicating cells with the predominant spot pattern L-O-R, initiation of replication first resulted in a L-O-O-R pattern, soon changing to O-L-R-O. After replication of the arms the predominant spot patterns were, L-O-R L-O-R, O-R-L R-O-L or O-L-R L-O-R indicating that one or both arms passed an origin and the other arm. To study the driving force for these movements cell growth was inhibited with rifampicin allowing run-off DNA synthesis. Similar spot patterns were obtained in growing and non-growing cells, indicating that the movement of arms is not a growth-sustained process, but may result from DNA synthesis itself. The distances between loci on different arms (LR-distances) and between duplicated loci (LL- or RR-distances) as a function of their distance from the origin, indicate that in slow-growing cells DNA is organized according to the so-called sausage model and not accordingto the doughnut model. |
| first_indexed | 2024-12-21T19:12:31Z |
| format | Article |
| id | doaj.art-b4f547a335b64e20b2c7f2ebc396fa6e |
| institution | Directory Open Access Journal |
| issn | 1664-302X |
| language | English |
| last_indexed | 2024-12-21T19:12:31Z |
| publishDate | 2015-05-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Microbiology |
| spelling | doaj.art-b4f547a335b64e20b2c7f2ebc396fa6e2022-12-21T18:53:10ZengFrontiers Media S.A.Frontiers in Microbiology1664-302X2015-05-01610.3389/fmicb.2015.00448128569Segregation of chromosome arms in growing and non-growing Escherichia coli cellsConrad L. Woldringh0Flemming G. Hansen1Norbert O.E. Vischer2Tove eAtlung3University of AmsterdamTechnical University of DenmarkUniversity of AmsterdamRoskilde UniversityIn slow-growing Escherichia coli cells the chromosome is organized with its left (L) and right (R) arms lying separated in opposite halves of the nucleoid and with the origin (O) in-between, giving the pattern L-O-R. During replication one of the arms has to pass the other to obtain the same organization in the daughter cells: L-O-R L-O-R. To determine the movement of arms during segregation six strains were constructed carrying three coloured loci: the left and right arms were labeled with red and cyan fluorescent-proteins, respectively, on loci symmetrically positioned at different distances from the central origin, which was labeled with green-fluorescent protein. In non-replicating cells with the predominant spot pattern L-O-R, initiation of replication first resulted in a L-O-O-R pattern, soon changing to O-L-R-O. After replication of the arms the predominant spot patterns were, L-O-R L-O-R, O-R-L R-O-L or O-L-R L-O-R indicating that one or both arms passed an origin and the other arm. To study the driving force for these movements cell growth was inhibited with rifampicin allowing run-off DNA synthesis. Similar spot patterns were obtained in growing and non-growing cells, indicating that the movement of arms is not a growth-sustained process, but may result from DNA synthesis itself. The distances between loci on different arms (LR-distances) and between duplicated loci (LL- or RR-distances) as a function of their distance from the origin, indicate that in slow-growing cells DNA is organized according to the so-called sausage model and not accordingto the doughnut model.http://journal.frontiersin.org/Journal/10.3389/fmicb.2015.00448/fullEscherichia colinucleoidDNA segregationchromosome arms (replichores)rifampicin treatmentrun-off DNA synthesis |
| spellingShingle | Conrad L. Woldringh Flemming G. Hansen Norbert O.E. Vischer Tove eAtlung Segregation of chromosome arms in growing and non-growing Escherichia coli cells Frontiers in Microbiology Escherichia coli nucleoid DNA segregation chromosome arms (replichores) rifampicin treatment run-off DNA synthesis |
| title | Segregation of chromosome arms in growing and non-growing Escherichia coli cells |
| title_full | Segregation of chromosome arms in growing and non-growing Escherichia coli cells |
| title_fullStr | Segregation of chromosome arms in growing and non-growing Escherichia coli cells |
| title_full_unstemmed | Segregation of chromosome arms in growing and non-growing Escherichia coli cells |
| title_short | Segregation of chromosome arms in growing and non-growing Escherichia coli cells |
| title_sort | segregation of chromosome arms in growing and non growing escherichia coli cells |
| topic | Escherichia coli nucleoid DNA segregation chromosome arms (replichores) rifampicin treatment run-off DNA synthesis |
| url | http://journal.frontiersin.org/Journal/10.3389/fmicb.2015.00448/full |
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