Download Animal and Plant viruses

Animal and Plant viruses
Plate Culture of Animal Viruses
Figure 6.33
Figure 6.20
Papillomavirus (DNA) Life Cycle
Figure 6.22
Picornavirus (RNA) Life Cycle
Figure 6.23
Figure 11.15
Poliovirus Structure
• The capsid is fundamentally icosahedral.
•
- Composed of three external proteins (VP1–3)
•
- VP4 protein subunits coat the interior and help
package the (+) strand RNA genome.
Figure 11.11B
• The poliovirus binds
to poliovirus
receptor (PVR)
through its VP2 and
VP3 subunits.
•
-A
conformational
change in VP1
allows insertion of
the genome into the
cytoplasm.
Figure 11.12
Poliovirus Replication
• In the cytoplasm, the RNA is translated to make three
large precursor peptides: P1–3.
•
- All three peptides are eventually cleaved by
proteases to generate 11 proteins.
Figure 11.13A
Influenza Virus Structure
• The flu virus has no geometric capsid.
• RNA genome is loosely contained by a shell of matrix
proteins.
Figure 11.16
RNA segments are coated with
nucleocapsid proteins (NPs).
Two major envelope proteins:
- Neuraminidase (NA)
- Hemagglutinin (HA)
Influenza virus: note envelope
The Genome of Influenza A Virus
Figure 11.17
• The key advantage of a segmented genome is that it
facilitates recombination between two strains
coinfecting the same cell.
•
- Instant new strain can evade the immune system.
Figure 11.18B
Influenza Virus Entry
• Animation: Influenza Virus Entry into a Cell
Click box to launch animation
Figure 11.21
Influenza Virus Replication
• Animation: Influenza Virus Replication
Click box to launch animation
Herpes Simplex Virus Structure
• An icosahedral capsid houses the dsDNA
genome.
Capsid is surrounded by a
protein tegument,
which is contained
within an envelope
with spike proteins.
Figure 11.31A
Figure 11.32
Herpes Virus Replication
• Animation: Herpes Virus Replication
Click box to launch animation
• Within a plant, the thick cell walls prevent a
lytic burst or budding out of virions.
•
- Instead, plant viruses are transmitted to
uninfected cells by plasmodesmata.
Figure 6.26
Fig. 19-11
tRNA-like
structure
Stop
codon
Cap
MTH
RNP
MP
CP
A viroid
Figure 6-6 Viroids: infective RNA.
Figure 6-7 Prion disease.