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Flashcards in Retroviridae Deck (73)
1

Pro genes of retroviruses encode

Protease

2

Characteristics of Deltaretroviruses

Complex 

Type C Morphology

Gag, Pro, Pol, Env, rex and tex - Gag, Pro and Pol presented in 3 different reading frames

Exogenous

3

Feline Immunodeficiency Virus (FIV) belongs to what genus of retroviruses

Lentivirus

4

Type C Retrovirus

Assemble at plasma membrane and contain central symmetrically placed spherical inner core

5

Most common form of avian leukosis of chickens 4-30 weeks old

Lymphoid Leukosis

6

Retroviruses that cause chronic transformation do so by

Insertion/mutation through random integration into the genome of the host

7

Retroviruses that infect chickens belong to what retrovirus groups

Alpharetrovirus

Gammaretrovirus

8

Incubation period of FIV

Long incubation period - may last as long as 6 years

9

Characteristics of Betaretroviruses

Simple

Type B or Type D morphology

Assembled in cytoplasm via Type A intermediate

Gag, Pro, Pol, Env - Gag, Pro and Pol in different reading frames

Endogenous and Exogenous

10

Main determinant of FeLV pathogenicity

Surface Glycoprotein

11

Retrovirus virions are resistent to

Ultraviolet or X-rays

12

How do insects transmitt Equine Infectious Anemia Virus

When feeding fly is interrupted it will fly to another horse and transmit the virus

13

Gag gene of retroviruses encode

Virus core proteins: capsid, nucleocapsid, matrix

14

Secondary effects of thrombocytopenia seen with what retrovirus?

Equine Infectious Anemia Virus

15

Lymphoid Leukosis

Pale combs or cyanotic

Nodular lesions in teh bursa fabricuiuc containing B lymphocytes

16

Shape and position of the core was used to classify retroviruses into what categories

Type A - Type D

17

Equine infectious anemia virus - Swamp Fever - is transmitted through

Blood

Secretions 

Insects

18

Disease caused by what retrovirus?

Erythroblastosis

Avian Retrovirus

19

Viral oncogenes undergo transformation to remove

regulatory mechanisms

20

FIV replicates in what cells

Lymphocytes mostly CD4+ T cells, B cells and macrophages

21

Characteristics of Lentiviruses

Complex

Cylindrical or Conical Shaped Core

Gag, Pro, Pol, Env, Vif, Vpr, Vpo, Tat, Rev and Nef - Gag separate from Pol and Pro in same reading frame

Exogenous

22

Characteristics of Gammaretroviruses

Simple

Type C morphology

Gag, Pol, Pro, Env - Gag, Pro, Pol in same reading frame

Endogenous and Exogenous

23

Endogenous gammaretroviruses

Endogenous Feline Leukemia Virus (enFeLV)

RD114 Virus

24

FIV is transmitted by

Deep bite wounds and scratches

25

Characteristics of Retroviruses

Enveloped

Budd from cell membrane

Single Stranded

+ Sense RNA

26

Diagnose FeLV

p27 ELISA

Immunofluorescence Assay (IF)

Virus isolation in cell culture

27

FeLV subtype T

Tropism for T lymphocytes

28

FeLV is shed from an infected cat through

Saliva

Nasal Secretions

Feces

Milk

29

Oncogenic genes of avian retroviruses are transmitted

Horizontally or vertically through infectious virus or provirus integrated into host germ cell DNA

30

Diagnose FIV

ELISA

31

Important enzyme encoded by Retroviruses

Reverse Transcriptase

32

Clinical signs of Equine Infectious Anemia Virus

Anemia

Enlarged spleen

Swollen belly and legs - edema

 

33

Characteristics of Epsilonretroviruses

Complex

Type C morphology

Gag, Pro, Pol, Env, ORF (A,B and C) - Gag, Pro and Pol in same reading frame

Endogenous

 

34

Diagnose Equine Infectious Anemia Virus

Agar Gel Immunodiffusion - AGID or Coggins Test

35

Transmission of FeLV 

Mutal Grooming

Bites

36

Clinical signs of FeLV

Immunosuppression

Anemia (regenerative vs non-regenerative)

Lymphoma 

Leukemia

37

FeLV subtype C

Result of mutations in the Env gene of FeLV

38

Endogenous Avian Retroviruses

Occur in the genome of chickens as a provirus

39

Exogenous Replication Defective Avian Retroviruses

may acquire v-onc and induce malignant tumor rapidly

40

Rev Gene of lentiviruses

Encode a protein that facilitates transport of non-spliced viral RNA from the nucleus to the cytoplasm

41

Outcomes of retroviral infection

Release of virus by budding or lysis

Latent infection

Chronic infection

Virus induced transformation to malignancy

42

Characterisitcs of Alpharetroviruses

Simple

Type C morphology

Gag, Pro, Pol and Env - pro is at 3' end of gag in same reading frame

Exogenous and Endogenous

43

Important genes of retroviruses

Gag

Pol

Env

Pro

44

Exogenous Replication Competent Avian Retroviruses

Usually not pathogenic, but may cause disease in small percentage of chicken population

45

Pol gene of retroviruses encodes

Reverse Transcriptase

Integrase

46

Avian diseases associated with Alpharetroviruses

Avian leucosis

Myeloblastosis

Sarcoma virus

47

What is inside the nucleocapsid of Retroviruses

Viral RNA

Reverse transcriptase

Integrase

Protease

48

Mechanism of FIV

Attacks the immune system and weakens the immune response to infections and cancer

49

Equine infectious anemia virus replication begins when?

Infected monocytes enter the tissue and become macrophage

50

Clinical signs of FIV

Poor coat condition

Persistent fever

Gingivitis and Stomatis

Diarrhea

Progressive weight loss

51

Erythroblastosis

Cellular transformation of oncogenic virus

Anemia

Target progenitor erythroblasts

 

52

Disease caused by what retrovirus?

Lymphoid leukosis

Avian Retrovirus

53

Equine Infectious Anemia Virus belongs to which retrovirus genus

Lentivirus

54

To enter a cell and initiate infections retroviruses require

Interaction between a cell surface molecule and the envelope proteins on the virion surface

55

Retroviruses that can lead to acute transformation contain

Viral oncogenes (v-onc)

56

Env gene of retroviruses encodes

Virion envelope proteins, surface and transmembrane proteins

57

Characteristics of Spumaviruses

Complex

Spikes on surface, central but uncondensed core

Virions assembled in cytoplasm, budded into ER

Gag, Pro, Pol, Env, tas/bel-1, bet

Exogenous

58

Retroviruses integrate into the genome of the host by means of what enzyme

Integrase

59

Type B Retrovirus

Show a round but eccentrically positioned inner core

 

60

In chronic infection, Equine Infectious Anemia Virus infects what type of cell

Monocytes

_____________________

Cannot replicate in them

61

Osteoporosis - Thick Leg Syndrome

Caused by replication defective avian retroviruses

Affect long bones of legs

Uniform or irregular diaphyseal and metaphyseal thickening of affected bones

62

Avian diseases associated with Gammaretroviruses

Reticuloendotheliosis virus

63

Type D Retrovirus

Assemble in the cytoplasm via an A type intermediate and budding, show a distinct cylindrical core

64

Type A Retrovirus

Form extracellular structures which a characteristically thick shell with a hollow electron-lucent center

65

FeLV Subtype A

Ubiquitious and involved in every infection

66

Tat gene of Lentiviruses

Encodes transactivator that enhances the efficiency of cellular RNA polymerase

67

FeLV Subtype B

Originates from recombination of FeLV A and enFeLV

68

Nef gene of lentiviruses

Encodes Nef protein essential for replication in target hosts but not in cell culture and for downregulation expression of the CD4 molecule or alter the activation status of target cells

69

Vif gene of Retroviruses

Encodes protein Vif which enhances replication in lymphocytes

70

FeLV infection in queens results in

Embryonic death, still birth or viremic kittens

71

Feline Leukemia Virus belongs to what genus of retroviruses

Gammaretrovirus

72

T/F: Cellular oncogenes are required for normal cell growth and differentiation

True

73

Test used to diagnose what retroviral disease?

Coggins Test

Equine Infectious Anemia Virus