This video, we're going to continue to talk about animal viruses and animal virus infections by focusing specifically on DNA virus synthesis and replication. And so most DNA viruses that contain DNA as their genome will replicate inside of the host cell's cytoplasm. And it'll replicate inside of the host cell's cytoplasm using the host cell's components and hijacking the host cell's cellular machinery. However, most DNA viruses will actually encode their own viral DNA polymerase. And the viral DNA polymerase allows the viral DNA genome to replicate even when the host cell is not replicating. Now moving forward in our course, we're going to talk more details about the synthesis and replication of double stranded DNA viruses, and then later, we'll talk about the synthesis and replication of single stranded DNA viruses. And so I'll see you all in our next video.
- 1. Introduction to Microbiology3h 21m
- Introduction to Microbiology16m
- Introduction to Taxonomy26m
- Scientific Naming of Organisms9m
- Members of the Bacterial World10m
- Introduction to Bacteria9m
- Introduction to Archaea10m
- Introduction to Eukarya20m
- Acellular Infectious Agents: Viruses, Viroids & Prions19m
- Importance of Microorganisms20m
- Scientific Method27m
- Experimental DesignÂ30m
- 2. Disproving Spontaneous Generation1h 18m
- 3. Chemical Principles of Microbiology3h 38m
- 4. Water1h 28m
- 5. Molecules of Microbiology2h 23m
- 6. Cell Membrane & Transport3h 28m
- Cell Envelope & Biological Membranes12m
- Bacterial & Eukaryotic Cell Membranes8m
- Archaeal Cell Membranes18m
- Types of Membrane Proteins8m
- Concentration Gradients and Diffusion9m
- Introduction to Membrane Transport14m
- Passive vs. Active Transport13m
- Osmosis33m
- Simple and Facilitated Diffusion17m
- Active Transport30m
- ABC Transporters11m
- Group Translocation7m
- Types of Small Molecule Transport Review9m
- Endocytosis and Exocytosis15m
- 7. Prokaryotic Cell Structures & Functions5h 52m
- Prokaryotic & Eukaryotic Cells26m
- Binary Fission11m
- Generation Times16m
- Bacterial Cell Morphology & Arrangements35m
- Overview of Prokaryotic Cell Structure10m
- Introduction to Bacterial Cell Walls26m
- Gram-Positive Cell Walls11m
- Gram-Negative Cell Walls20m
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- The Glycocalyx: Capsules & Slime Layers12m
- Introduction to Biofilms6m
- Pili18m
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- Introduction to Prokaryotic Flagella12m
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- Review of Prokaryotic Surface Structures8m
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- Introduction to Bacterial Plasmids13m
- Cell Inclusions9m
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- 8. Eukaryotic Cell Structures & Functions2h 18m
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- Introduction to Microscopes8m
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- Introduction to Staining5m
- Simple Staining14m
- Differential Staining6m
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- Reviewing the Types of Staining8m
- Gram Stain13m
- 10. Dynamics of Microbial Growth4h 36m
- Biofilms16m
- Growing a Pure Culture5m
- Microbial Growth Curves in a Closed System21m
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- Reviewing the Environmental Factors of Microbial Growth12m
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- Growth Factors4m
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- Introduction to the Types of Culture Media5m
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- 11. Controlling Microbial Growth4h 10m
- Introduction to Controlling Microbial Growth29m
- Selecting a Method to Control Microbial Growth44m
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- Liquid Chemicals: Alcohols, Aldehydes, & Biguanides15m
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- Other Types of Liquid Chemicals14m
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- Review of Chemicals Used to Control Microbial Growth11m
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- 12. Microbial Metabolism5h 16m
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- ATP20m
- Enzymes14m
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- Types of Phosphorylation12m
- Glycolysis19m
- Entner-Doudoroff Pathway11m
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- Pyruvate Oxidation8m
- Krebs Cycle16m
- Electron Transport Chain19m
- Chemiosmosis7m
- Review of Aerobic Cellular Respiration19m
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- 13. Photosynthesis2h 31m
- 14. DNA Replication2h 25m
- 15. Central Dogma & Gene Regulation7h 14m
- Central Dogma7m
- Introduction to Transcription20m
- Steps of Transcription22m
- Transcription Termination in Prokaryotes7m
- Eukaryotic RNA Processing and Splicing20m
- Introduction to Types of RNA9m
- Genetic Code25m
- Introduction to Translation30m
- Steps of Translation23m
- Review of Transcription vs. Translation12m
- Prokaryotic Gene Expression21m
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- Introduction to Regulation of Gene Expression13m
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- Introduction to Eukaryotic Gene Regulation9m
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- 16. Microbial Genetics4h 44m
- Introduction to Microbial Genetics11m
- Introduction to Mutations20m
- Methods of Inducing Mutations15m
- Prototrophs vs. Auxotrophs13m
- Mutant Detection25m
- The Ames Test14m
- Introduction to DNA Repair5m
- DNA Repair Mechanisms37m
- Horizontal Gene Transfer18m
- Bacterial Transformation11m
- Transduction32m
- Introduction to Conjugation6m
- Conjugation: F Plasmids18m
- Conjugation: Hfr & F' Cells19m
- Genome Variability21m
- CRISPR CAS11m
- 17. Biotechnology3h 0m
- 18. Viruses, Viroids, & Prions4h 56m
- Introduction to Viruses20m
- Introduction to Bacteriophage Infections14m
- Bacteriophage: Lytic Phage Infections12m
- Bacteriophage: Lysogenic Phage Infections17m
- Bacteriophage: Filamentous Phage Infections8m
- Plaque Assays9m
- Introduction to Animal Virus Infections10m
- Animal Viruses: 1. Attachment to the Host Cell7m
- Animal Viruses: 2. Entry & Uncoating in the Host Cell19m
- Animal Viruses: 3. Synthesis & Replication22m
- Animal Viruses: DNA Virus Synthesis & Replication14m
- Animal Viruses: RNA Virus Synthesis & Replication22m
- Animal Viruses: Antigenic Drift vs. Antigenic Shift9m
- Animal Viruses: Reverse-Transcribing Virus Synthesis & Replication9m
- Animal Viruses: 4. Assembly Inside Host Cell8m
- Animal Viruses: 5. Release from Host Cell15m
- Acute vs. Persistent Viral Infections25m
- COVID-19 (SARS-CoV-2)14m
- Plant Viruses12m
- Viroids6m
- Prions13m
- 19. Innate Immunity7h 15m
- Introduction to Immunity8m
- Introduction to Innate Immunity17m
- Introduction to First-Line Defenses5m
- Physical Barriers in First-Line Defenses: Skin13m
- Physical Barriers in First-Line Defenses: Mucous Membrane9m
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- First-Line Defenses: Normal Microflora5m
- Introduction to Cells of the Immune System15m
- Cells of the Immune System: Granulocytes29m
- Cells of the Immune System: Agranulocytes25m
- Introduction to Cell Communication5m
- Cell Communication: Surface Receptors & Adhesion Molecules16m
- Cell Communication: Cytokines27m
- Pattern Recognition Receptors (PRRs)45m
- Introduction to the Complement System24m
- Activation Pathways of the Complement System23m
- Effects of the Complement System23m
- Review of the Complement System12m
- Phagoctytosis21m
- Introduction to Inflammation18m
- Steps of the Inflammatory Response26m
- Fever8m
- Interferon Response25m
- 20. Adaptive Immunity7h 14m
- Introduction to Adaptive Immunity32m
- Antigens12m
- Introduction to T Lymphocytes38m
- Major Histocompatibility Complex Molecules20m
- Activation of T Lymphocytes21m
- Functions of T Lymphocytes25m
- Review of Cytotoxic vs Helper T Cells13m
- Introduction to B Lymphocytes27m
- Antibodies14m
- Classes of Antibodies35m
- Outcomes of Antibody Binding to Antigen15m
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- Antibody Class Switching17m
- Affinity Maturation14m
- Primary and Secondary Response of Adaptive Immunity21m
- Immune Tolerance28m
- Regulatory T Cells10m
- Natural Killer Cells16m
- Review of Adaptive Immunity25m
- 21. Principles of Disease6h 57m
- Symbiotic Relationships12m
- The Human Microbiome46m
- Characteristics of Infectious Disease47m
- Stages of Infectious Disease Progression26m
- Koch's Postulates26m
- Molecular Koch's Postulates11m
- Bacterial Pathogenesis36m
- Introduction to Pathogenic Toxins6m
- Exotoxins Cause Damage to the Host40m
- Endotoxin Causes Damage to the Host13m
- Exotoxins vs. Endotoxin Review13m
- Immune Response Damage to the Host15m
- Introduction to Avoiding Host Defense Mechanisms8m
- 1) Hide Within Host Cells5m
- 2) Avoiding Phagocytosis31m
- 3) Surviving Inside Phagocytic Cells10m
- 4) Avoiding Complement System9m
- 5) Avoiding Antibodies25m
- Viruses Evade the Immune Response27m
Animal Viruses: DNA Virus Synthesis & Replication - Online Tutor, Practice Problems & Exam Prep
Animal viruses, particularly DNA viruses, replicate within host cells by utilizing the host's cellular machinery. Double-stranded DNA (dsDNA) viruses follow the central dogma, where transcription produces messenger RNA (mRNA), which is then translated into viral proteins. Single-stranded DNA (ssDNA) viruses convert their genome into dsDNA before undergoing similar processes. Both types synthesize viral proteins, including DNA polymerases for genome replication, leading to the assembly of new virions. Understanding these mechanisms is crucial for grasping viral pathogenesis and developing antiviral strategies.
Animal Viruses: DNA Virus Synthesis & Replication
Video transcript
Replication of Double-Stranded DNA (dsDNA) Viruses
Video transcript
This video, we're going to talk more details about the synthesis and replication, specifically of double stranded DNA viruses, or dsDNA viruses. And so double stranded DNA virus replication and expression actually follows the same steps as the central dogma of biology, as we talked about it in our previous lesson videos. And so that makes double stranded DNA virus synthesis and replication much easier to understand, because we kind of already talked about this in our previous lesson videos. And so recall that the complementary strands of double stranded DNA are referred to as the plus coding strand and the minus template strand. And so we refer to the double stranded DNA molecule as a plus-minus dsDNA, where again the plus strand indicates that there is a coding strand and the minus strand indicates that there is a template strand in this double stranded DNA molecule. And so, of course, this double stranded DNA molecule we know is gonna follow the same steps of the central dogma biology. And so transcription is gonna be able to produce the messenger RNA, and recall that the messenger RNA is the same exact thing as plus ssRNA or plus single-stranded RNA. And it is plus because it is encoding messages. And so, this mRNA or ssRNA or SS RNA that's made via transcription is then gonna be translated to make viral proteins. And so if we take a look at our image down below, what you'll notice is on the far left hand side we're showing you the double stranded DNA virus genome. And so it's a plus-minus double stranded DNA. And so when this double stranded viral genome is in the cell's cytoplasm, the cell's machinery is going to allow for protein synthesis, which is this entire top pathway, and that's going to occur via transcription where the double stranded DNA is used as a template for building plus ssRNA or messenger RNA. And, of course, this plus ssRNA or messenger RNA is going to encode the messages, allowing for translation to occur, and translation will build the viral proteins. Now these viral proteins can also include viral DNA polymerases that will allow for genome replication of the double stranded DNA virus genome. And so genome replication is always going to entail recreating the original viral genome. And so, the viral genome must be recreated and so of course it's going to lead to even more plus-minus double stranded DNA. And so, basically, the result here is that it's replicating the original genome and it's synthesizing viral proteins. And so once these viral proteins have been synthesized and the original genome has been replicated, then it can move on to the 4th stage of an animal virus infection, which is going to be assembly of these components. We’ll get to talk more about the assembly later in our course. But for now, this here concludes our brief lesson on the synthesis and replication of double stranded DNA or dsDNA viruses. We'll be able to get some practice applying these concepts, and then we'll talk about the synthesis and replication of single stranded DNA viruses. So I'll see you all in our next video.
Replication of Single-Stranded DNA (ssDNA) Viruses
Video transcript
This video, we're going to talk more details about the synthesis and replication of single stranded DNA viruses or ssDNA viruses. And so the good thing is that the replication of single stranded DNA viruses is actually quite similar to the synthesis and replication of double stranded DNA viruses. And really there's only just the addition of an extra step. And so ultimately what happens is that single stranded DNA viruses or ssDNA viruses are going to have a single stranded DNA genome, either a plus single stranded DNA of a coding strand or a minus single stranded DNA of a template strand. And so regardless if it's plus or minus, this single stranded DNA is going to be converted to a plus-minus double stranded DNA or dsDNA. And then at that point, once the double stranded DNA molecule has been generated, it is going to be very similar to the synthesis and replication that we saw with double stranded DNA viruses. And so what that means is that this double stranded DNA can be transcribed to form the messenger RNA or the plus ssRNA, which of course can go on to be translated to make viral proteins. And, this double stranded DNA molecule can also be used to replicate the original genome. And so it is going to be used to replicate this single stranded DNA genome. And so if we take a look at our image down below, we can get a better understanding of the synthesis and replication of single stranded DNA viruses. And so notice on the far left over here that we're showing you the original genome of the virus as it enters into the cell is going to be a single stranded or an ssDNA molecule. Now notice here we're indicating that it is a plus ssDNA molecule, but it could also be a minus ssDNA molecule. Now regardless if it is a plus or minus single stranded DNA molecule, it is going to be converted to a double stranded DNA molecule, a plus-minus double stranded DNA molecule. And then once the plus-minus double stranded DNA molecule has been generated, then synthesis and replication is going to be very similar to what we saw with, double stranded, DNA viruses. And so this double stranded DNA can be used as a template for transcription to build the plus ssRNA or the messenger RNA, and of course we know that the messenger RNA can be directly translated to form these viral proteins. And that includes the formation of viral enzymes, which can be used in genome replication, and genome is always going to replicate the original genome as it entered into the cell. And so what you'll see is that it is going to be plus ssDNA that is going to be replicated here. And so once again, here in this image we're showing you plus ssDNA, but it could also be minus ssDNA. And, the of course it's going to regenerate minus ssDNA if that were the case. But ultimately, once these viral proteins have been synthesized and the original viral genome has been replicated, these components can then assemble with each other, which is the next stage of an animal virus infection that we'll get to talk more about later in our course. But for now, this here concludes our brief lesson on the synthesis and replication of single stranded DNA viruses or ssDNA viruses. And we'll be able to get some practice applying these concepts as we move forward in our course. So I'll see you all in our next video.
Which of the following has never been found in a virus?
Which of the following is not a described type of animal virus?
What step is required in the synthesis of ssDNA viruses that is not required in the synthesis of dsDNA viruses?
Do you want more practice?
Here’s what students ask on this topic:
How do double-stranded DNA (dsDNA) viruses replicate within host cells?
Double-stranded DNA (dsDNA) viruses replicate within host cells by following the central dogma of biology. The dsDNA genome enters the host cell's cytoplasm and uses the host's cellular machinery for transcription. During transcription, the dsDNA is used as a template to produce messenger RNA (mRNA), which is equivalent to plus single-stranded RNA (ssRNA). This mRNA is then translated into viral proteins, including viral DNA polymerases. These polymerases are crucial for replicating the viral genome, ensuring the production of new dsDNA molecules. Once the viral proteins and replicated genomes are synthesized, they assemble into new virions, ready to infect other cells.
What is the role of viral DNA polymerase in DNA virus replication?
Viral DNA polymerase plays a critical role in the replication of DNA viruses. It is an enzyme encoded by the viral genome that allows the viral DNA to replicate independently of the host cell's replication cycle. This means that even if the host cell is not actively dividing, the viral DNA polymerase can still replicate the viral genome. This enzyme ensures the production of new viral DNA molecules, which are essential for the synthesis of new virions. By hijacking the host's cellular machinery, viral DNA polymerase facilitates the continuous replication and propagation of the virus within the host.
How do single-stranded DNA (ssDNA) viruses replicate their genome?
Single-stranded DNA (ssDNA) viruses replicate their genome by first converting their ssDNA into double-stranded DNA (dsDNA). This conversion can occur regardless of whether the ssDNA is a plus (coding) or minus (template) strand. Once the ssDNA is converted into dsDNA, the replication process mirrors that of dsDNA viruses. The dsDNA serves as a template for transcription, producing messenger RNA (mRNA), which is then translated into viral proteins. These proteins include viral enzymes necessary for genome replication. The dsDNA is also used to replicate the original ssDNA genome, ensuring the production of new viral particles.
What are the key differences between the replication of dsDNA and ssDNA viruses?
The key difference between the replication of double-stranded DNA (dsDNA) and single-stranded DNA (ssDNA) viruses lies in an additional step required for ssDNA viruses. While dsDNA viruses directly use their genome for transcription and replication, ssDNA viruses must first convert their single-stranded genome into double-stranded DNA. Once this conversion occurs, the replication process for both types of viruses becomes similar. The dsDNA is transcribed to produce messenger RNA (mRNA), which is then translated into viral proteins. These proteins include enzymes necessary for genome replication, leading to the production of new viral particles.
Why is understanding DNA virus replication important for developing antiviral strategies?
Understanding DNA virus replication is crucial for developing effective antiviral strategies. By comprehending the mechanisms through which these viruses hijack host cellular machinery, researchers can identify potential targets for antiviral drugs. For instance, inhibiting viral DNA polymerase can prevent the replication of the viral genome, thereby halting the production of new virions. Additionally, understanding the replication process helps in the development of vaccines and therapeutic interventions that can disrupt the viral life cycle. This knowledge is essential for controlling viral infections and reducing the impact of viral diseases on public health.