What is Generalised transduction?
Generalized transduction is the process by which any bacterial gene may be transferred to another bacterium via a bacteriophage, and typically carries only bacterial DNA and no viral DNA. In essence, this is the packaging of bacterial DNA into a viral envelope.
What do you mean by Lysogenic conversion?
Lysogenic conversion –> lysogeny. (Science: virology) The ability of some phages to survive in a bacterium as a result of the integration of their dna into the host chromosome. The integrated dna is termed a prophage.
What does the lambda repressor do?
The lambda repressor is a self assembling dimer also known as the cI protein. It binds DNA in the helix-turn-helix binding motif. It regulates the transcription of the cI protein and the Cro protein. The life cycle of lambda phages is controlled by cI and Cro proteins.
What is the end result of generalized transduction?
Generalized Transduction During this stage, random pieces of bacterial DNA are mistakenly packaged into a phage head, resulting in the production of a transducing particle.
How does generalized transduction work?
Generalized transduction occurs when random pieces of bacterial DNA are packaged into a phage. It happens when a phage is in the lytic stage, at the moment that the viral DNA is packaged into phage heads. If the virus replicates using ‘headful packaging’, it attempts to fill the head with genetic material.
What is the difference between lytic and lysogenic?
The difference between lysogenic and lytic cycles is that, in lysogenic cycles, the spread of the viral DNA occurs through the usual prokaryotic reproduction, whereas a lytic cycle is more immediate in that it results in many copies of the virus being created very quickly and the cell is destroyed.
Which disease is the result of Lysogeny?
The effect of lysogenic conversion can be seen clearly in the disease cholera. Cholera is caused by a Gram negative, curved rod called Vibrio cholerae. The bacterium is transmitted through contaminated water and results in severe diarrhea and rapid dehydration of the infected person.
What is a lysogen quizlet?
lysogen. A bacterium that carries phage DNA (the prophage) integrated into its genome.
What must happen in order for a lysogen to be maintained?
Lysogeny is maintained by the activity of a single protein species, the lambda repressor (CI), which acts as a transcription factor to repress all lytic functions from the prophage in the E. coli cell, as well as to regulate its own production (Figure 1A–C; Ptashne, 2004).
Why is lambda DNA used?
Lambda DNA (48,502 bp) may be used as a molecular weight size marker during nucleic acid gel analysis following digestion with a restriction enzyme (such as HindIII). Lambda DNA can also be used as a substrate in restriction enzyme activity assays.
What is the function of Cro protein?
In a purified transcription system, the Cro protein is an effective and specific repressor of RNA synthesis from the N and cro genes; thus Cro is an autorepressor which regulates its own synthesis.
What kind of phage is capable of lysogeny?
Phages capable of lysogeny are known as temperate phage or prophage. Lysogeny is commonly characterized by insertion of the viral genome into the host genome or other cell replicon (e.g., plasmid).
How is lysogeny used to protect the environment?
Holloway (1969) even estimated that 100% of all natural isolates of P. aeruginosa were lysogenic for at least one phage and that many of these bacteria contained several prophages. Lysogeny may be a method by which both phages and bacteria can be protected in the environment.
When does the lysogeny of a bacterium take place?
(Show more) Lysogeny, type of life cycle that takes place when a bacteriophage infects certain types of bacteria. In this process, the genome (the collection of genes in the nucleic acid core of a virus) of the bacteriophage stably integrates into the chromosome of the host bacterium and replicates in concert with it.
What causes a host to switch from lysogeny to lysis?
Triggers that lead to a switch from lysogeny to lysis may include environmental damage to the host or its genome or, conversely, a peak in host growth and fitness that provides optimal conditions for viral replication and eventual lysis.