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Flashcards in Retroviridae Deck (73)
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1
Q

Pro genes of retroviruses encode

A

Protease

2
Q

Characteristics of Deltaretroviruses

A

Complex

Type C Morphology

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

Exogenous

3
Q

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

A

Lentivirus

4
Q

Type C Retrovirus

A

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

5
Q

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

A

Lymphoid Leukosis

6
Q

Retroviruses that cause chronic transformation do so by

A

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

7
Q

Retroviruses that infect chickens belong to what retrovirus groups

A

Alpharetrovirus

Gammaretrovirus

8
Q

Incubation period of FIV

A

Long incubation period - may last as long as 6 years

9
Q

Characteristics of Betaretroviruses

A

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
Q

Main determinant of FeLV pathogenicity

A

Surface Glycoprotein

11
Q

Retrovirus virions are resistent to

A

Ultraviolet or X-rays

12
Q

How do insects transmitt Equine Infectious Anemia Virus

A

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

13
Q

Gag gene of retroviruses encode

A

Virus core proteins: capsid, nucleocapsid, matrix

14
Q

Secondary effects of thrombocytopenia seen with what retrovirus?

A

Equine Infectious Anemia Virus

15
Q

Lymphoid Leukosis

A

Pale combs or cyanotic

Nodular lesions in teh bursa fabricuiuc containing B lymphocytes

16
Q

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

A

Type A - Type D

17
Q

Equine infectious anemia virus - Swamp Fever - is transmitted through

A

Blood

Secretions

Insects

18
Q

Disease caused by what retrovirus?

A

Erythroblastosis

Avian Retrovirus

19
Q

Viral oncogenes undergo transformation to remove

A

regulatory mechanisms

20
Q

FIV replicates in what cells

A

Lymphocytes mostly CD4+ T cells, B cells and macrophages

21
Q

Characteristics of Lentiviruses

A

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
Q

Characteristics of Gammaretroviruses

A

Simple

Type C morphology

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

Endogenous and Exogenous

23
Q

Endogenous gammaretroviruses

A

Endogenous Feline Leukemia Virus (enFeLV)

RD114 Virus

24
Q

FIV is transmitted by

A

Deep bite wounds and scratches

25
Q

Characteristics of Retroviruses

A

Enveloped

Budd from cell membrane

Single Stranded

+ Sense RNA

26
Q

Diagnose FeLV

A

p27 ELISA

Immunofluorescence Assay (IF)

Virus isolation in cell culture

27
Q

FeLV subtype T

A

Tropism for T lymphocytes

28
Q

FeLV is shed from an infected cat through

A

Saliva

Nasal Secretions

Feces

Milk

29
Q

Oncogenic genes of avian retroviruses are transmitted

A

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

30
Q

Diagnose FIV

A

ELISA

31
Q

Important enzyme encoded by Retroviruses

A

Reverse Transcriptase

32
Q

Clinical signs of Equine Infectious Anemia Virus

A

Anemia

Enlarged spleen

Swollen belly and legs - edema

33
Q

Characteristics of Epsilonretroviruses

A

Complex

Type C morphology

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

Endogenous

34
Q

Diagnose Equine Infectious Anemia Virus

A

Agar Gel Immunodiffusion - AGID or Coggins Test

35
Q

Transmission of FeLV

A

Mutal Grooming

Bites

36
Q

Clinical signs of FeLV

A

Immunosuppression

Anemia (regenerative vs non-regenerative)

Lymphoma

Leukemia

37
Q

FeLV subtype C

A

Result of mutations in the Env gene of FeLV

38
Q

Endogenous Avian Retroviruses

A

Occur in the genome of chickens as a provirus

39
Q

Exogenous Replication Defective Avian Retroviruses

A

may acquire v-onc and induce malignant tumor rapidly

40
Q

Rev Gene of lentiviruses

A

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

41
Q

Outcomes of retroviral infection

A

Release of virus by budding or lysis

Latent infection

Chronic infection

Virus induced transformation to malignancy

42
Q

Characterisitcs of Alpharetroviruses

A

Simple

Type C morphology

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

Exogenous and Endogenous

43
Q

Important genes of retroviruses

A

Gag

Pol

Env

Pro

44
Q

Exogenous Replication Competent Avian Retroviruses

A

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

45
Q

Pol gene of retroviruses encodes

A

Reverse Transcriptase

Integrase

46
Q

Avian diseases associated with Alpharetroviruses

A

Avian leucosis

Myeloblastosis

Sarcoma virus

47
Q

What is inside the nucleocapsid of Retroviruses

A

Viral RNA

Reverse transcriptase

Integrase

Protease

48
Q

Mechanism of FIV

A

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

49
Q

Equine infectious anemia virus replication begins when?

A

Infected monocytes enter the tissue and become macrophage

50
Q

Clinical signs of FIV

A

Poor coat condition

Persistent fever

Gingivitis and Stomatis

Diarrhea

Progressive weight loss

51
Q

Erythroblastosis

A

Cellular transformation of oncogenic virus

Anemia

Target progenitor erythroblasts

52
Q

Disease caused by what retrovirus?

A

Lymphoid leukosis

Avian Retrovirus

53
Q

Equine Infectious Anemia Virus belongs to which retrovirus genus

A

Lentivirus

54
Q

To enter a cell and initiate infections retroviruses require

A

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

55
Q

Retroviruses that can lead to acute transformation contain

A

Viral oncogenes (v-onc)

56
Q

Env gene of retroviruses encodes

A

Virion envelope proteins, surface and transmembrane proteins

57
Q

Characteristics of Spumaviruses

A

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
Q

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

A

Integrase

59
Q

Type B Retrovirus

A

Show a round but eccentrically positioned inner core

60
Q

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

A

Monocytes

_____________________

Cannot replicate in them

61
Q

Osteoporosis - Thick Leg Syndrome

A

Caused by replication defective avian retroviruses

Affect long bones of legs

Uniform or irregular diaphyseal and metaphyseal thickening of affected bones

62
Q

Avian diseases associated with Gammaretroviruses

A

Reticuloendotheliosis virus

63
Q

Type D Retrovirus

A

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

64
Q

Type A Retrovirus

A

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

65
Q

FeLV Subtype A

A

Ubiquitious and involved in every infection

66
Q

Tat gene of Lentiviruses

A

Encodes transactivator that enhances the efficiency of cellular RNA polymerase

67
Q

FeLV Subtype B

A

Originates from recombination of FeLV A and enFeLV

68
Q

Nef gene of lentiviruses

A

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
Q

Vif gene of Retroviruses

A

Encodes protein Vif which enhances replication in lymphocytes

70
Q

FeLV infection in queens results in

A

Embryonic death, still birth or viremic kittens

71
Q

Feline Leukemia Virus belongs to what genus of retroviruses

A

Gammaretrovirus

72
Q

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

A

True

73
Q

Test used to diagnose what retroviral disease?

A

Coggins Test

Equine Infectious Anemia Virus