21. Orthomyxoviridae

Question 1

MEMBERS OF THE FAMILY ORTHOMYXOVIRIDAE (6 genera)

Answer 1

Influenzavirus A, (wild, domestic animals and birds)

Influenzavirus B, (humans)

Influenzavirus C, (humans and swine)

Thogotovirus, (tick-borne)

Quaranjavirus, (ticks and birds)

Isavirus (salmon)

Question 2

Which viruses have the following properties:

Virions are pleomorphic, spherical, or filamentous, 80-120 nm in diameter, and consist of an envelope with large spikes surrounding six to eight helically symmetrical nucleocapsid segments of different sizes

The genome consists of linear -ssRNA, divided into six to eight segments, 10-4.6 kb in overall size

There are two kinds of spikes (A & B virus); rod shaped, consisting of homotrimers of the hemagglutinin glycoprotein, and mushroom shaped, consisting of homotetramers of the neuraminidase protein

Transcription and RNA replication occur in the nucleus; capped 50 termini of cellular precursor mRNAs are cleaved and used as primers for mRNA transcription; budding takes place on the plasma membrane

Defective interfering particles and genetic reassortment occur frequently

Answer 2

Influenza viruses

Question 4

MEMBERS OF THE GENUS INFLUENZAVIRUS A (Fam. ORTHOMYXOVIRIDAE) (7 species)

Answer 4

1. AVIAN INFLUENZA VIRUSES
2. BAT INFLUENZA VIRUSES
3. BOVINE INFLUENZA D VIRUSES
4. CANINE INFLUENZA VIRUSES
5. EQUINE INFLUENZA VIRUSES
6. HUMAN INFLUENZA VIRUSES
7. SWINE INFLUENZA VIRUSES

Question 5

MEMBERS OF THE GENUS ISAVIRUS (Fam. ORTHOMYXOVIRIDAE) (1 species)

Answer 5

INFECTIOUS SALMON ANEMIA VIRUS