Lecturer: Dr. Christine Dupont!
B1 rm 277!
Email: [email protected]!
Ofce hours: Mon, Wed 1:30-2:30pm!
If you need to speak with me outside scheduled lecture time or !
ofce hours, please contact me via e
Virus Classication and Taxonomy
pg 31-40 !
Baltimore Classication; based on transcription strategy
Classical System; based on structure
A universal system for classifying viruses, and a
unied taxonomy, has been established by the
What is a virus?!
-genome (nucleic acid) encased in protein!
a piece of bad news wrapped in protein
Peter Medawar, Nobel prize medicine!
-infect cells, replicate, non-living (dene?), !
to Viral Infection!
Vol 2 pg 55-77, 87-123!
-rst line of defense!
-most are based on recognition of broad molecular motifs found!
commonly in pathogens by PRRs- pattern recognition receptors!
Global summary of the AIDS epidemic
Number of people living Total
33.4 million 34 m
with HIV in 2008
31.3 million 30.7 m
Women (aged 15 and above) 15.7 million 16.7 m
Children under 15 years
2.1 million 3.3 m
Viral egress - Assembly, exit, maturation !
pg 457-462, 464-474, 478-479, 490-493!
-most of what is known is based on in vitro studies!
-3D studies using X-ray crystallography, NMR analysis!
-ex vivo studies involving assembly intermediates of wildtype!
! pg 52-54!
-some viruses require movement to nucleus for transcription!
-some (like Picornaviridae) carry out transcription in the cytoplasm !
-to get to the nucleus, interaction with cytoskelet
Genetic diversity in RNA viruses pg 195-198!
-RNA virus populations frequently display great diversity!
-for a given RNA virus species, the genome sequences cluster !
around a consensus or average sequence, but every genome can be!
different from every
pg 207-223, 256-260!
pg 342-348, 357-361!
- (+) sense RNA viruses, but genome does not function as!
mRNA as it does with other (+) sense RNA viruses!
-distinguishing feature is replication strategy;!
RNADNAhost chromosome RNA!
chpt 4 acheson!
-viruses are metastable; primed to undergo structural !
-makes entry a step-wise, active process, triggered by cell interaction!
-coliphage e.g., T even , T odd , uncoating involves deposition of !
nucleic acid di
(-) sense RNA genomes!
Negative sense RNA animal virus:
a) Describe the morphology of this virus
b) If the genome is in segments, what family
might it belong to? Give an example of a virus
from this family
c) Predict how it carries out: