(birds, mice, sheep, cats, mondeys, goats, horses, humans)
- General Types of Pathology
- Oncoviruses - sarcomas and leukemias in wide assortment of animals
- Spumaviruses - cytophatic, "foamy" inclusions, but not associated with any known disease.
- Lentiviruses - chronic encephalopathies, pneumonias, arthritis, immune deficiencies and
equine hemolytic anemia.
- Simialar to most enveloped RNA viruses
- Internal nucleocore of proteins and RNA
- Cortex is icosahedral
- External envelope with some spikes. Envelope is like host cell glycocalyx (cf. bacterial "LPS").
- Type specific factors
- Group specfiic factors
- Dissimilar to other RNA viruses - diploid
R5 and R3 are long terminal repeats,
gag = internal proteins
pol = gp-pol = reverse transcriptase
env = envelope
src/onc = optional sarcogene/oncogene
- Chromosome can integrate into the host chromosome.
Chromosome (C), Reverse Transcriptase (RT), and Translation
- Two identical ssRNA's but linked near 5'ends
- In virions, ssRNA's are tightly linked to needed enzymes co-packaged inside
- Replication of the chromosome
- A specific tRNA attaches as a primer at P1
- Synthesis of strong stop (-)DNA: Reverse transcription by "polymerase" from P1 to R5
- The two ends of the RNA come close together, and the first jump by "polymerase" is made over to 3' end
- Elongation of (-)DNA from 3' end to P1
- RNase H nicks viral RNA twice yielding P2 primer.
- P2 primer primes strong stop (+)DNA
- RNase H cuts off tRNA
- Second jump to P1 on same or other strand.
- RNase H removes RNA primer and (-)DNA finishes replication
- (+)DNA completes replication
- Forms rolling circle.
- Reverse Transcriptase ("polymerase") has Mg++ and/or Mn++ as cofactor.
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