Persistence and expression of Microplitis demolitor polydnavirus in Pseudoplusia includens.
Persistence and expression of Microplitis demolitor polydnavirus (MdPDV) was examined in parasitized and virus-injected Pseudoplusia includens larvae. Viral DNA persisted in P. includens larvae for 6 days, but no increase in the amount of viral DNA present was detected. Viral transcripts were observed in parasitized and virus-injected larvae 4 h post-parasitism and expression continued for 6 days. When specific host tissues were examined, more viral DNA and RNA was detected in haemocytes than in the gut, nervous system and fat body. 32P-labelled MdPDV DNA hybridized to approximately six different size classes of mRNAs on Northern blots of RNA from haemocytes of parasitized larvae. MdPDV transcription was first detected in haemocytes at 4 h post-parasitism and continued for 6 days. Similar transcripts were observed in haemocytes from larvae that had been injected with calyx fluid or MdPDV plus venom. First-strand cDNA probes of haemocyte-specific MdPDV transcripts hybridized to only certain MdPDV viral DNAs, suggesting that only part of the MdPDV genome is expressed in this host cell type.
Strand
M R
MR
Department of Entomology, University of Wisconsin, Madison 53706.
McKenzie
D I
DI
Grassl
V
V
Dover
B A
BA
Aiken
J M
JM
D000818:Animals; D016367:Baculoviridae / Q000302:isolation & purification*; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D007814:Larva / Q000382:microbiology; D007915:Lepidoptera / Q000382:microbiology*; D012333:RNA, Messenger / Q000032:analysis; D012367:RNA, Viral / Q000032:analysis; D014863:Wasps / Q000382:microbiology*
D004279:DNA, Viral; D012333:RNA, Messenger; D012367:RNA, Viral