Comparison of penaeid shrimp and insect parvoviruses suggests that viral transfers may occur between two distantly related arthropod groups

Abstract

The DNA and putative amino acid sequences of representative insect and shrimp parvoviruses (subfamily Densovirinae) were analyzed using computer programs. Shrimp viruses included hepatopancreatic parvovirus (HPV) of Penaeus monodon (HPVmon) and P. chinensis (HPVchin), spawner-isolated mortality virus from P. monodon (SMVmon) and infectious hypodermal and hematopoietic necrosis virus (IHHNV) from P. vannamei. Insect viruses included Aedes aegypti densovirus ( AaeDNV), Aedes albopictus densovirus ( AalDNV), Junonia coenia densovirus ( JcDNV), Galleria mellonella densovirus ( GmDNV), Bombyx mori densovirus 5 ( BmDNV), Diatraea saccharalis densovirus ( DsDNV) and Periplaneta fuliginosa densovirus ( PfDNV). Virion size for all these viruses ranged between 18 and 30 nm diameter and ssDNA genome length was between 4 and 6 kb. Using blast or Clustal W with the sequence fragments available, no significant DNA homology was found except for 77% DNA identity between HPVmon and HPVchin. However, phylogenetic trees constructed by comparing DNA genome sequences for putative viral polypeptides, capsid proteins and nonstructural proteins placed the parvoviruses into two Clades: Clade 1 with SMVmon, PfDNV, DsDNV, GmDNV, JcDNV, and BmDNV; and Clade 2 with HPVmon, HPVchin, IHHNV, AalDNV and AaeDNV. The four shrimp parvoviruses fell into two different clades that grouped with different insect parvoviruses.