RETROVIRIDAE Flashcards
“Retro” means ?
Backwards
Describe the nucleotide sequence of Retroviridae.
Two linear positive-sense single strands of RNA
Unique enzyme of Retroviridae that transcribes viral RNA to double-stranded DNA
Reverse transcriptase
DNA copies of the viral genome of Retroviridae are synthesized in the ?
Cytoplasm
Enzyme responsible of integration into the host’s chromosomal DNA
Integrase
Retroviridae has low mutation rate. True or False?
False
Why does Genus Retroviridae has high mutation rate?
Due to the errors during reverse transcription
These are remnants of ancient retroviral infections, where copy of reverse transcribed viral DNA is integrated in chromosomal DNA after previous retrovirus infection.
Endogenous retroviruses
Type of retrovirus capable of horizontal transmission.
Exogenous retroviruses
Give the protein of Retroviridae with the given data:
Encodes the major structural nonglycosylated
polyproteins
gag
Give the protein of Retroviridae with the given data:
Encodes protease responsible for facilitating
viral protein maturation
pro
Give the protein of Retroviridae with the given data:
Encodes multifunctional protein that includes
reverse transcriptase and integrase enzyme
pol
Give the protein of Retroviridae with the given data:
Encodes the antigenic surface glycoproteins
and transmembrane protein
env
What are the important genera of Retroviridae classified as oncogenic?
- Genus Alpharetrovirus
- Genus Betaretrovirus
- Genus Gammaretrovirus
- Genus Deltavirus
- Genus Epsilonretrovirus
Genus Alpharetrovirus comprises what viruse/s? Give the diseases induced and the main transmission.
Avian Leukosis and Sarcoma Viruses
* Diseases: Leukemia, lymphomas, and sarcomas in poultry
* Transmission: Horizontal and Vertical (Egg Transmission)
Genus Betaretrovirus comprises what viruse/s? Give the diseases induced and the main transmission.
Jaagsiekte (“chase sickness” sheep retrovirus
* Diseases: Pulmonary adenocarcinoma in sheep; pulmonary adenomatosis (30%) leading to respiratory distress; chronic wasting; respiratory system failure; secondary pneumonia;
- Transmission: Horinzontal: Aerosolized secretions
Genus Gammaretrovirus comprises what viruse/s? Give the diseases induced and the main transmission.
Feline Leukemia Virus
* Diseases: Debilitating disease; (1) neoplastic disorders; (2) bone marrow suppression; (3) neurologic disorders; (4) immunodeficiency; (5) immune mediated diseases; (6) stomatitis
* Transmission: Saliva or milk either through mutual grooming (allo-grooming), bites, or from kittens nursing virus-infected dams
Genus Deltaretrovirus comprises what viruse/s? Give the diseases induced and the main transmission.
- Diseases: Most are subclinical; Enzootic bovine leukosis; multicentric lymphosarcoma; solid lymphoid tumors in cattle (generally not associated with leukema; abnormal immune function leading to immunosuppression
- Transmission: Horizontally: bodily fluids containing infected cells - blood and milk
