Expression of polydnavirus genes from the parasitoid wasp Cotesia kariyai m two noctuid hosts

Abstract

DNA purified from polydnavirus particles isolated from the parasitoid wasp Cotesia kariyai contained double-stranded closed circular molecules which were polydisperse in molecular weight. 2 days after viral injection into the host armyworm larvae viral DNA was detected in all tested larval tissues, including haemocytes, fat body, nerve cord and brain. Viral transcripts were also observed in all the tissues of virus-injected larvae. The most specific tissue was haemocytes because more viral DNA and RNA was detected than in the other tissues. Viral transcripts were not detected in haemocytes of virus-injected larvae of common cutworm. The present data suggest that C. kariyai virus (CkV) gene expression occurs species-specifically, although viral DNA can be detected in all tested tissues of the habitual host armyworm.