Please enable JavaScript.
Coggle requires JavaScript to display documents.
MED VIROLOGY 1(pt.1)-Origin & Diversity of HIV - Coggle Diagram
MED VIROLOGY 1(pt.1)-Origin & Diversity of HIV
Retroviruses
affect animal species & human
Cause life long infections in their host>>associated with chronic disorders(tumours and inflammatory & wasting disorders)
Family of HIV
2 copies
of viral genome in each virus particle contained in the
cylindrical core.
enveloped RNA viruses
Protein spikes in the envelope >> attach susceptible host
RV Replication
Enzyme Requirement:
reverse transcriptase(RT)
encoded by the virus
Flow of genetic information from RNA>DNA(reverse)
RV structure
3 structural genes>targets of ARVs
gag
: encodes the structural core....of the virus particle
very small genome(10kb)
env
: codes virus attachment available in the envelop of the virus. Engages with the cell's surface receptor
Pol
:Non-structural virus>encodes reverse transcriptase
Life cycle of RV
Viral genome
discharged
into the cytoplasm of cell
RT begins to make DNA copy of the viral RNA genome>uses both RNA copies of RNA To make
1st DNA strand
Envelope
fuses
with plasma membrane of the cell
1st DNA strand made>
RNA genomes degraded
> 2nd complementary DNA strand made
Virus
attaches
to susceptible cell via receptor on cell surface
2nd DNA strand
>goes to nucleus>integrates into host genome(point of no return, cell infected)>
pro-viral genome copy in the cell
>can stay
dormant
for yrs/
replicate
Replication cycle
triggered
>new viral genome
synthesized
>proteins synthesized>new virus particles
assembled
&
bud off
the cell membrane>can be
released
to affect new cells
Molecular Basis of Variation
2.Recombination>same cell is infected by 2 viruses(closely related)>enzyme can jump from one virus to another>produce
circulating recombinant virus
(Hybrid genome)>large genetic material changes
1.RT>makes mistakes when reading cDNA>
Point mutation
>changes nucleotide sequence>alters coding sequence of a protein/deleterious effects>Accumulation of mutations