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Diversity of
Variola virus
~200 kb dsDNA, ~200 ORFs
• Diversity of
Variola virus
strains is associated with geographic
distance
• Alastrim minor (South America) / Variola major (Asia): ~600 SNPs, ~80 Indels
Al t i
i
/ V i l i t
di t (W t Af i )
350 SNP 45 I d l
•
as r m m nor ar o a n erme a e es r ca :
~
s, ~ n e s
• Variola African minor/major / Variola major (Asia):
~150 SNPs, ~30 Indels
• Central region: virion structural proteins, enzymes - 30 gene
sequences are perfectly conserved or have only synonymous SNPs,
highly conserved, essential function.
• Left and Right end regions: Host range and immunomodulatory genes
- majority of Indels/frameshift mutations, fragmented sequences,
additional/absent of ORFs, - likely reflecting selection pressures.
•
Versus other
Orthopoxviruses
:
•
Variola / Camelpox-Taterapox viruses
:
~3200 SNPs, ~380 Indels
•
Variola / Monkeypox virus
:
~7500 SNPs, ~600 Indels
Diagnostics/Environmental Detection
“If further development of procedures for the
environmental detection of
Variola virus
or for
diagnostic purposes were to be pursued, more
extensive knowledge of the genome variability,
predicted protein sequences, virion surface
structure, and functionality of
Variola virus
from
widely dispersed geographic sources would be
needed.*”
* Assessment of Future Scientific Needs for Live
Variola Virus
; N.A.Press (1999)