DOI: 10.5061/dryad.x3ffbg7pb
title: Single-cell burst size estimates

description: Bacteriophage burst size is the average number of phage virions released
 from infected bacterial cells, and its magnitude depends on the duration
 of an intracellular progeny accumulation phase. Burst size is often
 measured at the population, not single-cell, level, and consequently,
 statistical moments are not commonly available. In this study, we
 estimated the bacteriophage lambda (λ) single-cell burst size mean and
 variance following different length intracellular accumulation periods by
 employing E. coli lysogens bearing lysis-deficient λ prophages. Single
 lysogens can be isolated and chemically lysed at desired times following
 prophage induction to quantify progeny intracellular accumulation within
 individual cells. Our data show that λ phage burst size initially
 increased exponentially with increased lysis time (i.e., period between
 induction and chemical lysis), and then saturated at longer lysis times.
 We also demonstrated that cell-to-cell variation or “noise” in lysis
 timing did not contribute significantly to burst size noise. The burst
 size noise remained constant with increasing mean burst size. The most
 likely explanation for the experimentally observed constant burst size
 noise was that cell-to-cell differences in burst size originated from
 intercellular heterogeneity in cellular capacities to produce phages. The
 mean burst size measured at different lysis times was positively
 correlated to cell volume, which may determine the cellular phage
 production capacity. However, experiments controlling for cell size
 indicated that there are other factors in addition to cell size that
 determine this cellular capacity.
description: Bacteriophage burst size is the average number of phage virions
 released from infected bacterial cells, and its magnitude depends on the
 duration of an intracellular progeny accumulation phase. Burst size is
 often measured at the population, not single-cell, level, and
 consequently, statistical moments are not commonly available. In this
 study, we estimated the bacteriophage lambda (λ) single-cell burst size
 mean and variance following different length intracellular accumulation
 periods by employing E. coli lysogens bearing lysis-deficient λ prophages.
 Single lysogens can be isolated and chemically lysed at desired times
 following prophage induction to quantify progeny intracellular
 accumulation within individual cells. Our data show that λ phage burst
 size initially increased exponentially with increased lysis time (i.e.,
 period between induction and chemical lysis), and then saturated at longer
 lysis times. We also demonstrated that cell-to-cell variation or “noise”
 in lysis timing did not contribute significantly to burst size noise. The
 burst size noise remained constant with increasing mean burst size. The
 most likely explanation for the experimentally observed constant burst
 size noise was that cell-to-cell differences in burst size originated from
 intercellular heterogeneity in cellular capacities to produce phages. The
 mean burst size measured at different lysis times was positively
 correlated to cell volume, which may determine the cellular phage
 production capacity. However, experiments controlling for cell size
 indicated that there are other factors in addition to cell size that
 determine this cellular capacity.