Ichnovirus

Ichnovirus is a genus of viruses, in the family Polydnaviridae. Parasitoid wasps serve as hosts, and these wasps are themselves parasitoids of Lepidoptera. There are 21 species in this genus.

Taxonomy
The genus Ichnovirus contained 21 species in ICTV version 1999a-2020: The genus Ichnoviriform contains 22 species starting ICTV version 2021 The species Ichnoviriform rostralis, previously known as Tranosema rostrale bracovirus was moved to ichnoviriform from bracoviriform (bracovirus) in 2021. Ichnoviriform fugitivi/Hyposoter fugitivus ichnovirus/HfIV: GenBank accession


 * SegA1: AY556383
 * SegA2-SegA3: AB291165-AB291166
 * SegB1: AY935249
 * SegB2-SegB6: AB291167-AB291171
 * SegB7: AY563518
 * SegB8: AY597814
 * SegB9-SegB10: AB291172-AB291173
 * SegB11: AY570798
 * SegB12-SegB16: AB291174-AB291178
 * SegB17: AY577428
 * SegB18: AB291179
 * SegC1: AB291180
 * SegC2: AY570799
 * SegC3-SegC9: AB291181-AB291187
 * SegC10: AY577429
 * SegC11: AB291188
 * SegC12: AY556384
 * SegC13-SegC20: AB291189-AB291195
 * SegD1-SegD4: AB291196-AB291199
 * SegD5: AY563519
 * SegD6-SegD12: AB291200-AB291206
 * SegE1: AB291207
 * SegE2: AB291208
 * SegG1: AB291209

Ichnoviriform fugitivi/Hyposoter fugitivus ichnovirus/HfIV: REFSEQ accession


 * SegA1: NC_008947
 * SegA2: NC_008957
 * SegA3: NC_008958
 * SegB1: NC_008956
 * SegB2: NC_008959
 * SegB3-SegB5: NC_008960-NC_008962
 * SegB6: NC_008999
 * SegB7: NC_008949
 * SegB8: NC_008955
 * SegB9: NC_008963
 * SegB10: NC_008964
 * SegB11: NC_008951
 * SegB12-SegB13: NC_008965-NC_008966
 * SegB14: NC_009000
 * SegB15: NC_008967
 * SegB16: NC_008968
 * SegB17: NC_008953
 * SegB18: NC_008969
 * SegC1: NC_008970
 * SegC2: NC_008952
 * SegC3-SegC9: NC_008971-NC_008979
 * SegC10: NC_008954
 * SegC11: NC_008980
 * SegC12: NC_008948
 * SegC13: NC_009001
 * SegC14-SegC15: NC_008981-NC_008982
 * SegC16: NC_008946
 * SegC17: NC_008983
 * SegC18: NC_008984
 * SegC19: NC_009002
 * SegC20: NC_008985
 * SegD1-SegD4: NC_008986-NC_008989
 * SegD5: NC_008950
 * SegD6-SegD12: NC_008990-NC_008996
 * SegE1: NC_009003
 * SegE2: NC_008997
 * SegG1: NC_008998

Ichnoviriform fumiferanae/Glypta fumiferanae ichnovirus/GfIV: GenBank accession


 * SegA1-SegA10: AB289903-AB289912
 * SegB1-SegB65: AB289913-AB289977
 * SegC1-SegC22: AB289978-AB289999
 * SegD1-SegD7: AB290000-AB290006
 * SegE1: AB290007

Ichnoviriform fumiferanae/Glypta fumiferanae ichnovirus/GfIV: REFSEQ accession


 * SegA1-SegA10: NC_008837-NC_008846
 * SegB1: NC_008847
 * SegB2: NC_008933
 * SegB3-SegB35: NC_008848-NC_008878
 * SegB36: NC_008936
 * SegB37-SegB47: NC_008879-NC_008889
 * SegB48: NC_008937
 * SegB49-SegB65: NC_008890-NC_008905
 * SegC1: NC_008939
 * SegC2-SegC7: NC_008906-NC_008911
 * SegC8: NC_008940
 * SegC9-SegC22: NC_008912-NC_008925
 * SegD1-SegD3: NC_008926-NC_008928
 * SegD4: NC_008941
 * SegD5-SegD7: NC_008929-NC_008931
 * SegE1: NC_008932

Structure
Viruses in Ichnovirus are enveloped, with prolate ellipsoid and cylindrical geometries. Genomes are circular and segmented, around 6.0-20kb in length.

Life cycle
Viral replication is nuclear. DNA-templated transcription is the method of transcription. The virus exits the host cell by nuclear pore export. Parasitoid wasps in the subfamilies Banchinae and Campopleginae serve as hosts, but these wasps are themselves parasites of lepidoptera. The wasp injects one or more eggs into its host along with a quantity of virus. The virus and wasp are in a symbiotic relationship: expression of viral genes prevents the wasp's host's immune system from killing the wasp's injected egg and causes other physiological alterations that ultimately cause the parasitized host to die. Transmission routes are parental.