Bacterial cells have certain receptors in their cellular membrane mosaic, and viruses act as a ligand that binds to a certain receptor. Receptors are inherently very specific to the ligands that can bind to them, so for a virus to attach to a receptor is a very unique process. In this way, viruses are very specific in the bacteria that they can target.
You mention the they take up viral DNA and… I couldn’t make out the end of that sentence, could you clarify what you said about temperate phages and what they’re good for?
I mentioned that bacteria with temperate phage viral DNA can show fluorescence, indicating to us that a certain bacterium is present. So, temperate phage are good for detecting the presence of a bacterium, while lytic phage are good at eliminating a certain bacterium.
Yeah, so temperate phages go through the lytic and lysogenic life cycles. This means that they allow the bacteria to replicate before lysing it. Lytic phages, on the other hand, will only go through the lytic cycle, meaning that they do not allow the bacteria to replicate before lysis. Siphoviridae is a different characteristic, it is a type of morphology that has to do with the long, noncontractile tail. Morphology and lytic/temperate behavior are unrelated, but both important in the process of isolating a phage.
I wondered the same thing. The clusters are created alphabetically, so cluster A was the first cluster, and cluster Z is the most recent. As phages genomes are sequenced, they are basically put into clusters that they fit into and are most similar to. If they aren’t like any other archived phage, they are put into their own, new cluster. What this means is that cluster Y is probably a relatively more recent break from another cluster of phages, so there have not been that many mutations within the Y cluster. There are only 4 archived cluster Y phages, because there probably aren’t as many phages within that cluster.
How are phages so specific to the bacteria they are able to target?
Bacterial cells have certain receptors in their cellular membrane mosaic, and viruses act as a ligand that binds to a certain receptor. Receptors are inherently very specific to the ligands that can bind to them, so for a virus to attach to a receptor is a very unique process. In this way, viruses are very specific in the bacteria that they can target.
You mention the they take up viral DNA and… I couldn’t make out the end of that sentence, could you clarify what you said about temperate phages and what they’re good for?
I mentioned that bacteria with temperate phage viral DNA can show fluorescence, indicating to us that a certain bacterium is present. So, temperate phage are good for detecting the presence of a bacterium, while lytic phage are good at eliminating a certain bacterium.
Very nice presentation! Can you explain the difference between lytic and temperate phage. Is the Siphovirade phage related to of one of those?
Yeah, so temperate phages go through the lytic and lysogenic life cycles. This means that they allow the bacteria to replicate before lysing it. Lytic phages, on the other hand, will only go through the lytic cycle, meaning that they do not allow the bacteria to replicate before lysis. Siphoviridae is a different characteristic, it is a type of morphology that has to do with the long, noncontractile tail. Morphology and lytic/temperate behavior are unrelated, but both important in the process of isolating a phage.
Great presentation! Why have so few cluster Y bacteriophages been identified?
I wondered the same thing. The clusters are created alphabetically, so cluster A was the first cluster, and cluster Z is the most recent. As phages genomes are sequenced, they are basically put into clusters that they fit into and are most similar to. If they aren’t like any other archived phage, they are put into their own, new cluster. What this means is that cluster Y is probably a relatively more recent break from another cluster of phages, so there have not been that many mutations within the Y cluster. There are only 4 archived cluster Y phages, because there probably aren’t as many phages within that cluster.