Difference Between Lytic and Lysogenic Cycle

Lytic vs Lysogenic Cycle

Lytic and Lysogenic cycles are the two cycles of viral reproduction. The lytic cycle involves the multiplication of bacteria, and at the end of the cycle, the cells are destroyed. The lysogenic cycle can also be referred to as lysogeny.

The lysogenic cycle is the initial cycle that occurs before the lytic cycle. In this cycle, a new genetic material (a prophage) is formed due to the coalescence between the nucleic acid in the bacteriophage and the host bacterium’s genome. The new genetic material is then transmitted to the other daughter cells. In the presence of ultraviolet radiation, they release the prophage; after which, proliferation occurs. The lysogenic cycle is also known to occur in eukaryotes, but these cases are still being researched for further comprehension.

After proliferation occurs, the lytic cycle begins. In the lytic cycle, there is propenyphage, and the particles are produced. The host bacterium is then destroyed by lysis (part of the lytic cycle). These are the main differences between the two cycles. There is no propenyphage in the lysogenic cycle, and the host bacterium is also not destroyed in this cycle, rather, there is a relationship between the bacteria and the phage. The DNA involved in the phage becomes a part of the chromosomes of the bacteria. There is a multiplication of the viral genome. A provirus is formed when the viral gene is inserted into the chromosome of the host, and this provirus can lead to the lytic cycle, and the destruction of cells can occur.

The lytic cycle, which occurs in bacteria and viruses, takes place in three stages ‘“ viral infection, replication and viral destruction. The life cycle of the lytic cycle can also be described in three phases ‘“ eclipse period, intracellular accumulation phase, and the lysis and release phase.

M-RNA’s and proteins are formed in the eclipse phase, and there are no infectious particles present. The proteins are referred to as late proteins. They contain phage, and are required for the lysis of the cell. Infectious particles are, however, formed in the intracellular accumulation phase, and in this phase, there is a combination of nucleic acid and structural proteins. In the last phase, there is lysis. Lysis occurs due to the accumulation of phage protein. Thousands of particles are released for one infected bacterium.

Summary:

1.Unlike in the lysogenic cycle, particles are present in the lytic cycle.
2.The bacteria is destroyed by the lysis phase in the lytic cycle, but no lysis occurs in the lysogenic cycle.
3.The lysogenic cycle is followed by the lytic cycle, but the lytic cycle cannot be followed by the lysogenic cycle.
4.Propenyphage occurs in the lytic cycle, but not in the lysogenic cycle.
5.The host bacterium is destroyed in the lytic cycle, whereas, no bacterium is destroyed in the lysogenic cycle.

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