bacoluvirus

Question 1

morphology

Answer 1

rod-shaped virions occluded in protein capsules

polyhedral shaped occlusion bodies (OBs)

Question 2

infection cycle

Answer 2

ODVs infect cells (primary infection), replication and packaging into BVs and OBs happens in the nucleus, BVs infect other cells.

Question 3

BV vs ODV

Answer 3

BV: one nucleocapsid per vision
ODV: number of nucleocapsids per virion varies (genomes are identical). BV: cell membrane, ODV inner nuclear membrane.

Question 4

baculovirus genome

Answer 4

circular genome
dsDNA
90-180ORFs

Question 5

regulation of baculovirus gene expression

Answer 5

early (immediate and delayed) and late (late and very late). distinction is made with DNA replication.

Question 6

viral RNA polymerase

Answer 6

LEF-4 capping enzyme, LEF-8/9 (polymerase subunit), P47 unknown.

Question 7

IE1 protein and hr elements

Answer 7

IE1: immediate early protein I: transactivator of own and other early genes. homologous repeats (hr): palindromic sequences ori’s, enhancers of gene expression. both needed for replication.

Question 8

genera of baculovirus

Answer 8

Alphabaculovirus (NPV)
Betabaculovirus (GV)
gammabaculovirus (NPV)
deltabaculovirus (NPV)

Question 9

granuloviruses and nucleopolyhedroviruses

Answer 9

GP have one virion per OB, one nucleocapsid per virion OB made of granulin. NPV more virions per OB, one or more nucleocapsids per virion. OB formed with polyhedrin protein.

Question 10

Budded virus fusion proteins

Answer 10

GP64 and F protein. Only group I alphabaculoviruses have GP64. GP64 5 potential glycosylation sites, forms a trimer via covalently linked S-S bridges.
F protein has 2 parts (F1/2) which are linked by S-S.

Question 11

Per os infectivity (PIF) factors

Answer 11

ODV proteins essential for oral infectivity, but not required for BV-driven infection.