why can’t there be specialized transduction with a lytic virus?

Conversion of Bacterial cell to a Phage Factory 4. What is the structure and genome of a typical plant virus? There are viruses that are capable of remaining hidden or dormant inside the cell in a process called latency. RNA viruses can contain +ssRNA that can be directly read by the ribosomes to synthesize viral proteins. A virus undergoes lytic and lysogenic cycles to reproduce. Viral contents are released into the cell, where viral enzymes convert the single-stranded RNA genome into DNA and incorporate it into the host genome. The third stage of infection is biosynthesis of new viral components. Some viral infections can be chronic if the body is unable to eliminate the virus. Examples of this are demonstrated by the poliovirus, which exhibits tropism for the tissues of the brain and spinal cord, or the influenza virus, which has a primary tropism for the respiratory tract. Discuss the difference between generalized and specialized transduction. All viruses depend on cells for reproduction and metabolic processes. Two days later, Duncan returned to the hospital by ambulance. After examination, an emergency department doctor diagnosed him with sinusitis, prescribed some antibiotics, and sent him home. Viral infection can be asymptomatic (latent) or can lead to cell death (lytic infection). There are two types of transduction: generalized and specialized transduction. Whereas chickenpox affects many areas throughout the body, shingles is a nerve cell-specific disease emerging from the ganglia in which the virus was dormant. (credit: modification of work by Randal J. Schoepp). The major threat to the survival of omnipresent bacteria is the much simpler viruses. In many cases these viruses express genes that keep the viral DNA dormant; that is, the virus does not im… During the lytic cycle of virulent phage, the bacteriophage takes over the cell, reproduces new phages, and destroys the cell. Their genetic material is contained in a prism shaped head, surrounded by a protein capsid. Transduction a bacterial virus transfers DNA from one cell to another 107 What. Bacteriophages replicate only in the cytoplasm, since prokaryotic cells do not have a nucleus or organelles. Animal viruses do not always express their genes using the normal flow of genetic information—from DNA to RNA to protein. The virus may remain silent or undergo productive infection without seriously harming or killing the host. Instead of packaging viral DNA, it takes a random piece of host DNA and inserts it into the capsid. Once inside, phages can follow one of two different life cycles: lytic or lysogenic. How is RecA protein involved in DNA repair. This video illustrates the stages of the lysogenic life cycle of a bacteriophage and the transition to a lytic phase. During the lytic cycle of viral replication, the virus hijacks the host cell, degrades the host chromosome, and makes more viral genomes. To establish a systemic infection, the virus must enter a part of the vascular system of the plant, such as the phloem. After entering the host cell, the virus synthesizes virus-encoded endonucleases to degrade the bacterial chromosome. Lytic animal viruses follow similar infection stages to bacteriophages: attachment, penetration, biosynthesis, maturation, and release (see Figure 4). During the lytic cycle of viral replication, the virus hijacks the host cell, degrades the host chromosome, and makes more viral genomes. Genetic transfer of host gene by bacteriophage occurs in two ways-generalized transduction and specialized transduction.In generalized transduction, virtually any genetic marker can be transferred from donor to recipient cell but it occurs at a low frequency. There are five stages in the bacteriophage lytic cycle (see Figure 1). Answer a. Transduction is the name for the transfer of genetic information from one bacterium to another bacterium by a phage. The life cycle begins with the penetration of the virus into the host cell. The ssDNA is then made into dsDNA, which can integrate into the host chromosome and become a permanent part of the host. What is the name for the transfer of genetic information from one bacterium to another bacterium by a phage? This unique recognition can be exploited for targeted treatment of bacterial infection by phage therapy or for phage typing to identify unique bacterial subspecies or strains. Ebola virus is transmitted through direct contact with droplets of bodily fluids such as saliva, blood, and vomit. Share it! However, some viruses can only be transferred by a specific type of insect vector; for example, a particular virus might be transmitted by aphids but not whiteflies. The presence of the phage may alter the phenotype of the bacterium, since it can bring in extra genes (e.g., toxin genes that can increase bacterial virulence). In a lysogenic cycle, the phage genome also enters the cell through attachment and penetration. Or should the drugs perhaps be reserved for health-care providers working to contain the disease? The RdRP is brought in by the virus and can be used to make +ssRNA from the original −ssRNA genome. The DNA can then recombine with host chromosome, giving the latter new characteristics. (b) After a period of latency, the virus can reactivate in the form of shingles, usually manifesting as a painful, localized rash on one side of the body. Why can’t there be specialized transduction with a lytic virus? It is capable of attaching to the bacterial cell wall and injecting its DNA to the bacterium. Duncan could conceivably have transmitted the disease to others at any time after he began having symptoms, presumably some time before his arrival at the hospital in Dallas. Specialized transduction occurs at the end of the lysogenic cycle, when the prophage is excised and the bacteriophage enters the lytic cycle. Its double-stranded DNA genome becomes incorporated in the host DNA. Click for a larger image. The virus life cycle is complete when it is transmitted from an infected plant to a healthy plant. Figure 2. Like it? Virus-mediated transfection, also known as transduction, offers a means to reach hard-to-transfect cell types for protein overexpression or knockdown, and it is the most commonly used method in clinical research (Glover et al., 2005; Pfeifer and Verma, 2001). Is RNA-dependent RNA polymerase made from a viral gene or a host gene? r/explainlikeimfive: Explain Like I'm Five is the best forum and archive on the internet for layperson-friendly explanations. Like many animal viruses, plant viruses can have either a DNA or RNA genome and be single stranded or double stranded. Which phage life cycle is associated with which forms of transduction? Transduction occurs when a bacteriophage transfers bacterial DNA from one bacterium to another during sequential infections. When the bacteriophage inserts its genetic content into the genome of the next bacterium, the… History at your fingertips Sign up here to see what happened On This Day, every day in your inbox! How does reverse transcriptase aid a retrovirus in establishing a chronic infection? An enzyme from HIV that can make a copy of DNA from RNA is called _________________. T-even phage is a good example of a well-characterized class of virulent phages. The final stage is release. Discuss some methods by which plant viruses are transmitted from a diseased plant to a healthy one. On the other hand, is it ethical to withhold potentially life-saving drugs from dying patients? RNA viruses that infect animal cells often replicate in the cytoplasm. Discuss the advantages and disadvantages for the phage. The excised DNA is then packaged into a new virus particle, which can then deliver the DNA to a new bacterium, where the donor genes can be inserted into the recipient chromosome or remain in the cytoplasm, depending on the … Single-stranded RNA viruses such as HIV carry a special enzyme called reverse transcriptase within the capsid that synthesizes a complementary ssDNA (cDNA) copy using the +ssRNA genome as a template. As it assembles and packages DNA into the phage head, packaging occasionally makes a mistake. A virus obtains its envelope during which of the following phases? In eukaryotic cells, most DNA viruses can replicate inside the nucleus, with an exception observed in the large DNA viruses, such as the poxviruses, that can replicate in the cytoplasm. Eventually, the damage to the immune system results in progression of the disease leading to acquired immunodeficiency syndrome (AIDS). There are three types of RNA genome: dsRNA, positive (+) single-strand (+ssRNA) or negative (−) single-strand RNA (−ssRNA). Figure 3. The outbreak in West Africa in 2014 was unprecedented, dwarfing other human Ebola epidemics in the level of mortality. The majority of plant viruses are positive-strand ssRNA and can undergo latency, chronic, or lytic infection, as observed for animal viruses. The second stage of infection is entry or penetration. or In transduction, DNA is transferred from cell to cell through the agency of viruses NOTE :- All phages can be transducer and not all bacteria are transducible If no viable host cells remain, the viral particles begin to degrade during the decline of the culture (see Figure 8). As it assembles and packages DNA into the phage head, packaging occasionally makes a mistake. Many viruses target specific hosts or tissues. The phage head and remaining components remain outside the bacteria. 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