Group i ds DNA viruse

1. Pandoravirus
salinus
Group: I (dsDNA viruses)
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Dr. Syed Dawood Shah
Mirpur University of Science & Technology AJK, Pakistan

2. Introduction
 Pandoravirus salinus is the largest known virus to
date.
 Discovered by Professor Jean-Michel Claverie and
Professor Chantal Abergel. Both of them are
evolutionary biologists at the Aix-Marseille University
of France.
 The existence of Pandoravirus salinus hint the
unknown parts of the tree of life and also suggest
the existence of the fourth domain because only 7%
of their genes match those in existing databases
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3. Structure
 The size of P. salinus is 1 μm long and 0.5 μm across,
which is large enough to be observed under a bright field
microscope.
 P. salinus is that they have a collection of 2,556 genes in
their genome
 Their micrometer-sized ovoid particles contain DNA
genomes of at least 2.5 and 1.9 megabases, respectively
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4. Classification
 Group: I (dsDNA viruses)
 Family: Pandoraviridae
 Genus: Pandoravirus
 Species: Salinus
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5. Genome
Linear, dsDNA genome of about
2,473kb that encodes potentially
for 2556 ORFs.
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6. Replication
 NUCLEO-CYTOPLASMIC Replication cycle lasts 10-15
hours.
 Virion binds to host cell and enters into host cell by
phagocytosis
 Fusion of viral envelope with cellular membrane at
virion apical pore, inducing the release of viral DNA
into host cytoplasm.
 Host cell nucleus shrinks, indicating possible
degradation of host chromosomes.
 Synthesis of early proteins.
 Replication of genomic DNA.
 Late proteins synthesis, assembly of new virions in the
cytoplasmic factories
 Cell lysis and virion release in the extracellular space.
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7. Ecology
and
Pathogenesis
 It is reported that the virus was isolated from the
mouth of Chile's Tunquen River located in central of
Chile
 Furthermore, another member of the Pandoravirus genus,
Pandoravirus dulcius were found in a freshwater pond near
Melbourne, Australia
 Therefore, their habitat is most likely to be in water. Based
on Claverie and Abergel's observation, the Pandoraviruses
parasitize amoebas
 Thus, it is concluded that the P. salinus infect their host via
lytic life cycle.
 Additionally, the researchers who are responsible for the
discovery said that these megaviruses which live
underwater, are so far harmless to mankind
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8. Thank You!
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