Lysogenic Conversion
Lysogenic Conversion - Related Videos
00:43
Lysogenic Cycle of Bacteriophages
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2019
In contrast to the lytic cycle, phages infecting bacteria via the lysogenic cycle do not immediately kill their host cell. Instead, they combine their genome with the host genome, allowing the bacteria to replicate the phage DNA along with the bacterial genome. The incorporated copy of the phage genome is called the prophage. Some prophages can re-activate and enter the lytic cycle. This often occurs in response to a perturbation, such as DNA damage, but can also transpire in the absence of...
09:23
Understanding the Impact of Temperate Bacteriophages on Their Lysogens Through Transcriptomics
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Cited by 2 •
2024
This protocol enables the impact of prophages on their hosts to be revealed. Bacterial cultures are synchronized using conditions that best support the lysogenic state, limiting spontaneous induction. RT-qPCR unequivocally distinguishes prophage-restricted genes and those uncoupled from phage control from those that are expressed during the lytic replication cycle.
03:17
Measuring Spontaneous Phage Induction in Lysogenic Bacteria Over Time
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2026
Source: Krishnamurthi, R., et al. Understanding the Impact of Temperate Bacteriophages on Their Lysogens Through Transcriptomics. J. Vis. Exp. (2024).This video demonstrates the temporal enumeration of spontaneous phage induction in lysogenic Pseudomonas aeruginosa by quantifying viable bacterial cells (CFUs) and infective phage particles (PFUs) over time. By sampling at defined intervals during growth and analyzing both colony and plaque formation, the method reveals when spontaneous induction...
02:08
Gene Conversion
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2020
Other than maintaining genome stability via DNA repair, homologous recombination plays an important role in diversifying the genome. In fact, the recombination of sequences forms the molecular basis of genomic evolution. Random and non-random permutations of genomic sequences create a library of new amalgamated sequences. These newly formed genomes can determine the fitness and survival of cells. In bacteria, homologous and non-homologous types of recombination lead to the evolution of new...
01:16
Viral Replication: Lysogenic Cycle
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2025
The lysogenic cycle is a crucial viral replication strategy that allows bacteriophages to persist within host cells without immediately destroying them. This process is primarily observed in temperate phages, such as bacteriophage lambda (λ), which infects Escherichia coli. The cycle allows the viral genome to persist across bacterial generations while keeping host cells viable.Integration of the Viral GenomeUpon infection, bacteriophage lambda attaches to the bacterial surface and injects its...
FAQs
The integrated phage genome can express selected genes while the bacterial host grows and divides. If those genes encode a toxin or another factor affecting bacterial behavior, they can change observable traits without replacing the host’s entire genetic program. This helps explain why bacteria carrying related phage genomes may differ in phenotype and disease potential.
When the phage genome resides in the bacterial chromosome, it is maintained within the host genetic material as the bacterium grows and divides. Phage-encoded traits can therefore pass to descendant cells rather than remaining limited to the initially infected cell. This inheritance provides a mechanism through which a phage-associated phenotype can persist within a bacterial lineage.
The effect depends on which phage genes are expressed in the bacterial host. Genes that encode toxins or other factors influencing bacterial behavior can increase disease potential, whereas the broader outcome depends on how those products alter the bacterium’s phenotype. Consequently, lysogenic conversion connects specific phage genetic content with differences in pathogenic behavior.
By introducing heritable phage genes into a bacterial lineage, the process can generate new traits that affect behavior and interactions with hosts. Those traits may alter disease potential and provide variation on which bacterial evolution can act. Studying these changes also reveals how host-phage interactions contribute to the emergence of distinct bacterial strains.
A study typically examines a temperate bacteriophage and its bacterial host, determines whether the phage genome becomes integrated as a prophage, and then assesses gene expression and bacterial traits during host growth. Researchers can compare the resulting phenotype and disease-related properties with those of bacteria lacking the relevant phage-associated changes.
It is particularly relevant when researchers investigate why bacterial strains differ in virulence, adaptation, or behavior despite sharing a bacterial species background. The process provides a framework for examining toxin-associated traits, prophage gene expression, and host-phage interactions. These applications also support research into gene transfer and the emergence of pathogenic bacterial strains.