Nice poster! I took this course before but I forget how the plaque assay differs between the phage life cycles, and in particular, I’m interested in how the halo around a bacterial plaque indicates a lysogenic life cycle. Could you explain this?
The halo around the plaque indicates the 20% of phage undergoing the lysogenic lifecycle. The lysogenic lifecycle is when a phage integrates its DNA into the DNA of the host bacterium turning that bacterium into a prophage. This does not lyse the bacteria until a repressor gene is deactivated causing the phage to lyse the cell, killing it in the process. Phage that produce lytic plaques undergo the lytic cycle 100% of the time lysing the host bacterium and these plaques are clear and have no halo around their edges.
The lytic cycle is the most effective at killing a host bacterium. This is because phage that produce temperate plaques undergo the lysogenic lifecycle 20% of the time. The lysogenic lifecycle is when a phage integrates its DNA into the DNA of the host bacterium turning that bacterium into a prophage. This does not lyse the bacteria until a repressor gene is deactivated causing the phage to lyse the cell, killing it in the process. Phage that produce lytic plaques undergo the lytic cycle 100% of the time lysing the host bacterium.
The lytic cycle is more effective in lysing the bacteria because this phage lyses the bacterial cell 100% of the time. Phages that undergo the temperate lifecycle have a 20% chance of not lysing the host bacterium and undergo the lysogenic lifecycle. The lysogenic lifecycle is when a phage integrates its DNA into the DNA of the host bacterium turning that bacterium into a prophage. This does not lyse the bacteria until a repressor gene is deactivated causing the phage to lyse the cell, killing it in the process.
In order to modify a temperate phage to only undergo the lytic lifecycle one would modify the phages DNA to not contain a Repressor gene. The repressor gene is involved with the lysogenic lifecycle. One could possibly also sequence the specific phages genome and compare this to species of known lytic phage in the same cluster and sub cluster. Your could look for differences in the genome and these could be what’s contributing to this phage being able to undergo the lysogenic lifecycle as well.
We chose the name Shiniqua because it means a woman who is a victor coming from Japanese origins. Our phage was found near Varisty pond on the northwestern part of campus.
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Nice poster! I took this course before but I forget how the plaque assay differs between the phage life cycles, and in particular, I’m interested in how the halo around a bacterial plaque indicates a lysogenic life cycle. Could you explain this?
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The halo around the plaque indicates the 20% of phage undergoing the lysogenic lifecycle. The lysogenic lifecycle is when a phage integrates its DNA into the DNA of the host bacterium turning that bacterium into a prophage. This does not lyse the bacteria until a repressor gene is deactivated causing the phage to lyse the cell, killing it in the process. Phage that produce lytic plaques undergo the lytic cycle 100% of the time lysing the host bacterium and these plaques are clear and have no halo around their edges.
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Is the lytic or temperate cycle more effective in killing the bacteria? Or does it not matter?
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The lytic cycle is the most effective at killing a host bacterium. This is because phage that produce temperate plaques undergo the lysogenic lifecycle 20% of the time. The lysogenic lifecycle is when a phage integrates its DNA into the DNA of the host bacterium turning that bacterium into a prophage. This does not lyse the bacteria until a repressor gene is deactivated causing the phage to lyse the cell, killing it in the process. Phage that produce lytic plaques undergo the lytic cycle 100% of the time lysing the host bacterium.
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The lytic cycle is more effective in lysing the bacteria because this phage lyses the bacterial cell 100% of the time. Phages that undergo the temperate lifecycle have a 20% chance of not lysing the host bacterium and undergo the lysogenic lifecycle. The lysogenic lifecycle is when a phage integrates its DNA into the DNA of the host bacterium turning that bacterium into a prophage. This does not lyse the bacteria until a repressor gene is deactivated causing the phage to lyse the cell, killing it in the process.
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Do you have any idea how you would go about genetically modifying the phage to enter the lytic cycle?
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In order to modify a temperate phage to only undergo the lytic lifecycle one would modify the phages DNA to not contain a Repressor gene. The repressor gene is involved with the lysogenic lifecycle. One could possibly also sequence the specific phages genome and compare this to species of known lytic phage in the same cluster and sub cluster. Your could look for differences in the genome and these could be what’s contributing to this phage being able to undergo the lysogenic lifecycle as well.
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What made you decide on the name for your phage? Where on the campus of CU boulder was it found?
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We chose the name Shiniqua because it means a woman who is a victor coming from Japanese origins. Our phage was found near Varisty pond on the northwestern part of campus.
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