The lytic and lysogenic are the two main important terms of viral replication. They are the outstanding model of the life cycle of viruses. They take on the host cell and this host cell is maintained by the virus and also controls its cellular mechanism. There are differences between these two terms. Let’s discuss them in this article.
Lytic vs Lysogenic Cycle
The main difference between lytic and lysogenic cycles is that In the lytic cycle, the host of DNA gets hydrolyzed on the other hand in the case of the lysogenic cycle the host of DNA does not get hydrolyze. The prophage stage does not present in the lytic cycle on the other hand in the lysogenic cycle prophage stage exists. The lytic cycle emerges within a concise duration whereas the lysogenic cycle requires much time.
The lytic cycle executes over the host cell to produce its phage particles and eventually destroys all other cells. It starts with a virulent phage. The T shape phage is the best illustration of how the phases of the lytic cycle perform their function. Lytic completes its cycle within four-six stages.
The lysogenic cycle has a proper continuous cycle; it does not have any stages. The phage penetrates the host cell by the penetration and attachment procedure. Lambda phage is the best example for the explanation of the lysogenic cycle. The expression of the viral phage is genome but it is not involved in the cycle process completely.
Comparison Table Between Lytic And Lysogenic Cycle
| Parameters of Comparison | Lytic Cycle | Lysogenic Cycle |
| Time Duration | Cycle completed in Short period. | Cycle completed in a Long period. |
| The virulence | The cycle is shown by virulent bacteriophages. | The cycle is virulent and shows fewer bacteriophages. |
| Lysis of bacteria cell | In this cycle, lysis occurs. | In this cycle, lysis does not occur. |
| Integration of viral DNA with DNA host | In this cycle, integration does not occur. | In this cycle, integration does not occur. |
| The formation of the Prophage | The cycle does not form prophages. | Cycle formed a prophage. |
| Virus formation within the cell | Many viruses formed within the cell. | In this cycle, no virus formed within the cell. |
What is Lytic Cycle?
It is one of the processes of viral reproduction which guide us to bacteriophage and bacterial viruses. This cycle gives us the results in the obliteration of the membrane and infected cells. The bacteriophages of the lytic cycle are known as virulent phages. They are different from temperature phages. The viral deoxyribonucleic acid or DNA exists separately in the bacterial cell as a free-floating molecule and replicates are present there separated from the aDNA host. Another name of the lytic cycle is also a “reproductive cycle” of the bacteriophages.
Lytic completed its cycle in six stages such as penetration, attachment, transcription, maturation, lysis, and biosynthesis. Let’s discuss them all one by one. In the attachment, cycle the phage binds itself to the shell of the host cell just for the injection of DNA into the cell. In the penetration cycle already the process of injecting starts so the phage infiltrates DNA into the host by penetrating by the cell membrane.
In the transcription, DNA is adulterated via the host cell. The metabolism of the cell is supervised to start phage biosynthesis. In this biosynthesis procedure, the DNA phage imitates internally in the cell and synthesizes new phage proteins and DNA.
What is Lysogenic Cycle?
The lysogenic cycle is a very important cycle of reproduction of viruses. It is also called Lysogeny and it is represented by the integration of bacteriophage nucleic acid into the host bacterium genome or the appearance of a circular replicon in the cytoplasm of bacteria. In this state, the bacterium reproduces and lives naturally. The hereditary material of the bacteriophage is called a prophage and it is transferred to daughter cells to each succeeding cellular division and it releases. It releases through UV radiation or with certain chemicals.
The lysogenic cycle also occurs in eukaryotes. DNA phage first blends in bacterial chromosomes for producing more phage. And in this cycle host, DNA is not hydrolyzed. DNA is replicated only not released proteins. It does not result in instantaneous lysing of the host cell. The procedure of transformation in this host phenotype is known as phage conversion or lysogenic conversion.
In this, some bacteria are also present which are less virulent such as clostridium botulinum, Vibrio cholera. The whole procedure which involves a bacterium being infected by a temperate phage is called lysogeny. It does not kill the host; the prophage genome integrates itself. DNA replicated passed through new daughter cells during bacterial reproduction.
Main Differences Between Lytic Cycle and Lysogenic Cycle
- In the case of lytic cycle cellular mechanism is entirely taken over by the viral genome whereas in the case of lysogenic cycle cellular mechanism of the host is slightly distributed by the viral genome.
- The lytic cycle indicate the signs of viral replication; on the other hand, the lysogenic cycle does not indicate the signs of viral replication.
- The lytic cycle does not permit genetic recombination inside host bacterium whereas the lysogenic cycle permits the genetic recombination.
- Efficiency of viral DNA is increased in the lytic cycle whereas in lysogenic the Efficiency of DNA is reduced.
- The lytic cycle produces progeny of the virus whereas lysogenic does not yield viral progeny due to fact that the viral particles are not liberated.
Conclusion
Here we talk about both the terms in brief with their differences but let’s know the similarities between these two terms also. They both take place within the host cell. Both moderate DNA replication. Both cycles produce thousands of copies of viruses.
The main feature of the lytic cycle is that it kills their host cell but lysogenic cells don’t kill the host cell. And the lysogenic cycle is triggered by starvation or exposure to toxic chemicals. The basic terms were used in this article which is also very important to know so don’t forget to learn all the basic terms first.
References
- https://aslopubs.onlinelibrary.wiley.com/doi/abs/10.4319/lo.2013.58.2.0465
- https://academic.oup.com/femsle/article-abstract/363/7/fnw047/2197796