H. Shike et al., Infectious hypodermal and hematopoietic necrosis virus of shrimp is related to mosquito Brevidensoviruses, VIROLOGY, 277(1), 2000, pp. 167-177
We purified and sequenced infectious hypodermal and hematopoietic necrosis
virus (IHHNV), a small DNA virus of shrimp, from wild Penaeus stylirostris.
The virion has a buoyant density of 1.45 as determined by cesium chloride
gradient. Analysis of 3873 nucleotides of the viral genome revealed three l
arge open reading frames (ORFs) and parts of the noncoding termini of the v
iral genome. The left, mid, and right ORFs on the complementary (plus) stra
nd have potential coding capacities of 666 amino acids (aa) (75.77 kDa), 36
3 aa (42.11 kDa), and 329 aa (37.48 kDa), respectively. The overall genomic
organization is similar to that of the mosquito brevidensoviruses. The lef
t ORF most likely encodes the major nonstructural (NS) protein (NS-1) since
it contains conserved replication initiator motifs and NTP-binding and hel
icase domains similar to those in NS-1 from all other parvoviruses. The IHH
NV putative NS-1 shares the highest aa sequence homology with the NS-1 of m
osquito brevidensoviruses, Aedes densovirus and Aedes albopictus parvovirus
. A search for putative splicing sites revealed that the N-terminal region
of NS-1 is very likely located in a small ORF upstream of the left ORF. The
right ORF is presumed to encode structural polypeptides (VPs), as in other
parvoviruses. Two putative promoters, located upstream of the left and rig
ht ORFs, are presumed to regulate expression of NS and VP genes, respective
ly. Thus, IHHNV is closely related to densoviruses of the genus Brevidensov
irus in the family Parvoviridae, and we therefore propose to rename this vi
rus Penaeus stylirostris densovirus(PstDNV). (C) 2000 Academic Press.