TY - JOUR

T1 - Physiological states of individual Salmonella typhimurium cells monitored by in situ reverse transcription-PCR.

AU - Hølmstrom, K

AU - Tolker-Nielsen, Tim

AU - Molin, S

N1 - Keywords: Base Sequence; Cell Cycle; DNA Primers; Gene Expression Regulation, Bacterial; Genes, Bacterial; GroEL Protein; Heat; Peptide Elongation Factors; RNA, Bacterial; RNA, Messenger; Reverse Transcriptase Polymerase Chain Reaction; Salmonella typhimurium

PY - 1999

Y1 - 1999

N2 - The possibility of using levels of specific mRNAs in individual bacteria as indicators of single-cell physiology was investigated. Estimates of the numbers of groEL and tsf mRNAs per cell in Salmonella typhimurium cells in different physiological states were obtained by Northern analysis. The average number of groEL mRNAs per cell was estimated to be 22 in fast-growing cultures and 197 in heat-shocked cultures. The average number of tsf mRNAs per cell was estimated to be 37 in fast-growing cultures, 4 in slow-growing cultures, and 0 in nongrowing cultures. The potential of mRNA-targeted in situ reverse transcription (RT)-PCR to monitor quantitatively different levels of groEL and tsf mRNA in individual cells and thus monitor both specific gene induction and general growth activity was assessed. Neither groEL nor tsf mRNA was present in stationary-phase cells, but it was shown that stationary-phase cells contain other RNA species at high levels, which may provide a possibility for monitoring directly stationary-phase individual cells by the use of in situ RT-PCR. The outcome of the in situ RT-PCR analyses indicated that a population of fast-growing cells is heterogeneous with respect to groEL mRNA single-cell contents, suggesting a cell-cycle-controlled expression of groEL in S. typhimurium, whereas a fast-growing culture is homogeneous with respect to tsf mRNA single-cell contents, suggesting that the level of tsf mRNA is relatively constant during the cell cycle.

AB - The possibility of using levels of specific mRNAs in individual bacteria as indicators of single-cell physiology was investigated. Estimates of the numbers of groEL and tsf mRNAs per cell in Salmonella typhimurium cells in different physiological states were obtained by Northern analysis. The average number of groEL mRNAs per cell was estimated to be 22 in fast-growing cultures and 197 in heat-shocked cultures. The average number of tsf mRNAs per cell was estimated to be 37 in fast-growing cultures, 4 in slow-growing cultures, and 0 in nongrowing cultures. The potential of mRNA-targeted in situ reverse transcription (RT)-PCR to monitor quantitatively different levels of groEL and tsf mRNA in individual cells and thus monitor both specific gene induction and general growth activity was assessed. Neither groEL nor tsf mRNA was present in stationary-phase cells, but it was shown that stationary-phase cells contain other RNA species at high levels, which may provide a possibility for monitoring directly stationary-phase individual cells by the use of in situ RT-PCR. The outcome of the in situ RT-PCR analyses indicated that a population of fast-growing cells is heterogeneous with respect to groEL mRNA single-cell contents, suggesting a cell-cycle-controlled expression of groEL in S. typhimurium, whereas a fast-growing culture is homogeneous with respect to tsf mRNA single-cell contents, suggesting that the level of tsf mRNA is relatively constant during the cell cycle.

M3 - Journal article

C2 - 10074064

VL - 181

SP - 1733

EP - 1738

JO - Journal of Bacteriology

JF - Journal of Bacteriology

SN - 0021-9193

IS - 6

ER -