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Factors affecting daughter cells' arrangement during the early bacterial divisions.

Su PT, Yen PW, Wang SH, Lin CH, Chiou A, Syu WJ - PLoS ONE (2010)

Bottom Line: Consistent with our proposition, the HA gel differs from agar by suppressing the typical side-by-side alignments to a rare population.Examination of bacterial surface molecules that may contribute to the daughter cells' arrangement yielded an observation that, with disrupted lpp, the E. coli daughter cells increasingly formed non-typical patterns, i.e. neither sliding side-by-side in parallel nor forming elongated strings.Therefore, our results suggest strongly that the early cell patterning is affected by multiple interaction factors.

View Article: PubMed Central - PubMed

Affiliation: Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan, Republic of China.

ABSTRACT
On agar plates, daughter cells of Escherichia coli mutually slide and align side-by-side in parallel during the first round of binary fission. This phenomenon has been previously attributed to an elastic material that restricts apparently separated bacteria from being in string. We hypothesize that the interaction between bacteria and the underneath substratum may affect the arrangement of the daughter bacteria. To test this hypothesis, bacterial division on hyaluronic acid (HA) gel, as an alternative substratum, was examined. Consistent with our proposition, the HA gel differs from agar by suppressing the typical side-by-side alignments to a rare population. Examination of bacterial surface molecules that may contribute to the daughter cells' arrangement yielded an observation that, with disrupted lpp, the E. coli daughter cells increasingly formed non-typical patterns, i.e. neither sliding side-by-side in parallel nor forming elongated strings. Therefore, our results suggest strongly that the early cell patterning is affected by multiple interaction factors. With oscillatory optical tweezers, we further demonstrated that the interaction force decreased in bacteria without Lpp, a result substantiating our notion that the side-by-side sliding phenomenon directly reflects the strength of in-situ interaction between bacteria and substratum.

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Related in: MedlinePlus

Appearance of daughter bacteria growing on LB-HA gel.JW1923, a fliG-deleted K-12 strain, was grown on a LB-HA (0.5%)-coated slide and the first two rounds of bacterial division were imaged by time-lapsed microscopy. (A) Formation of 4-cell arrays; (B) Patterning in a string; (C) Representatives of non-typical arrangements. Scale bar: 5 µm.
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pone-0009147-g001: Appearance of daughter bacteria growing on LB-HA gel.JW1923, a fliG-deleted K-12 strain, was grown on a LB-HA (0.5%)-coated slide and the first two rounds of bacterial division were imaged by time-lapsed microscopy. (A) Formation of 4-cell arrays; (B) Patterning in a string; (C) Representatives of non-typical arrangements. Scale bar: 5 µm.

Mentions: We reasoned that the interaction between the bacteria and the agar beneath the bacteria may play a critical role in the formation of the array structures. To examine this, the supporting agar matrix on slides was replaced with HA, a component of glycosaminoglycan with the ability to interfere with the adherence of microorganisms (US patent 6,428,903 B1) and perturb the attachment of E. coli to urothelium [12], [13]. Figure 1 shows the representative patterns of daughter cells taken from the flagellum- JW1923 on the gel of LB-0.5% HA, including cells arrayed in parallel (2.7%; n = 110) (Figure 1A), linear strings of four cells (27.3%) (Figure 1B), and miscellaneous patterns (70.0%) (Figure 1C). To exclude the possible metabolism of bacteria with HA, cross-linked HA gel was used to repeat the experiments, and similar results were obtained. Interestingly, in comparison with JW1923, the parental BW25113 strain gave no cells at all forming 4-cell array under the same condition (data not shown). This observation suggests that the force generated by the flagellar motion may also affect the daughter cells' patterning.


Factors affecting daughter cells' arrangement during the early bacterial divisions.

Su PT, Yen PW, Wang SH, Lin CH, Chiou A, Syu WJ - PLoS ONE (2010)

Appearance of daughter bacteria growing on LB-HA gel.JW1923, a fliG-deleted K-12 strain, was grown on a LB-HA (0.5%)-coated slide and the first two rounds of bacterial division were imaged by time-lapsed microscopy. (A) Formation of 4-cell arrays; (B) Patterning in a string; (C) Representatives of non-typical arrangements. Scale bar: 5 µm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2818839&req=5

pone-0009147-g001: Appearance of daughter bacteria growing on LB-HA gel.JW1923, a fliG-deleted K-12 strain, was grown on a LB-HA (0.5%)-coated slide and the first two rounds of bacterial division were imaged by time-lapsed microscopy. (A) Formation of 4-cell arrays; (B) Patterning in a string; (C) Representatives of non-typical arrangements. Scale bar: 5 µm.
Mentions: We reasoned that the interaction between the bacteria and the agar beneath the bacteria may play a critical role in the formation of the array structures. To examine this, the supporting agar matrix on slides was replaced with HA, a component of glycosaminoglycan with the ability to interfere with the adherence of microorganisms (US patent 6,428,903 B1) and perturb the attachment of E. coli to urothelium [12], [13]. Figure 1 shows the representative patterns of daughter cells taken from the flagellum- JW1923 on the gel of LB-0.5% HA, including cells arrayed in parallel (2.7%; n = 110) (Figure 1A), linear strings of four cells (27.3%) (Figure 1B), and miscellaneous patterns (70.0%) (Figure 1C). To exclude the possible metabolism of bacteria with HA, cross-linked HA gel was used to repeat the experiments, and similar results were obtained. Interestingly, in comparison with JW1923, the parental BW25113 strain gave no cells at all forming 4-cell array under the same condition (data not shown). This observation suggests that the force generated by the flagellar motion may also affect the daughter cells' patterning.

Bottom Line: Consistent with our proposition, the HA gel differs from agar by suppressing the typical side-by-side alignments to a rare population.Examination of bacterial surface molecules that may contribute to the daughter cells' arrangement yielded an observation that, with disrupted lpp, the E. coli daughter cells increasingly formed non-typical patterns, i.e. neither sliding side-by-side in parallel nor forming elongated strings.Therefore, our results suggest strongly that the early cell patterning is affected by multiple interaction factors.

View Article: PubMed Central - PubMed

Affiliation: Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan, Republic of China.

ABSTRACT
On agar plates, daughter cells of Escherichia coli mutually slide and align side-by-side in parallel during the first round of binary fission. This phenomenon has been previously attributed to an elastic material that restricts apparently separated bacteria from being in string. We hypothesize that the interaction between bacteria and the underneath substratum may affect the arrangement of the daughter bacteria. To test this hypothesis, bacterial division on hyaluronic acid (HA) gel, as an alternative substratum, was examined. Consistent with our proposition, the HA gel differs from agar by suppressing the typical side-by-side alignments to a rare population. Examination of bacterial surface molecules that may contribute to the daughter cells' arrangement yielded an observation that, with disrupted lpp, the E. coli daughter cells increasingly formed non-typical patterns, i.e. neither sliding side-by-side in parallel nor forming elongated strings. Therefore, our results suggest strongly that the early cell patterning is affected by multiple interaction factors. With oscillatory optical tweezers, we further demonstrated that the interaction force decreased in bacteria without Lpp, a result substantiating our notion that the side-by-side sliding phenomenon directly reflects the strength of in-situ interaction between bacteria and substratum.

Show MeSH
Related in: MedlinePlus