Use of specific single stranded DNA probes cloned in M13 to study the RNA synthesis of four temperature-sensitive mutants of HK/68 influenza virus.

Specific single stranded DNA probes have been obtained for both influenza virion RNA (vRNA) and complementary RNA (cRNA) by cloning a hemagglutinin gene fragment in the single stranded DNA phase M13. These probes were used for hybridization with the total labeled RNA from cytoplasmic extracts of infected cells. MDCK cells were infected with temperature-sensitive mutants of influenza HK/68 and the production of the virus specific RNA species was analysed at both permissive and restrictive temperatures. Results show that two NP mutants which undergo intracistronic complementation exhibit two different phenotypes at the non permissive temperature: ts2C is poly A cRNA and vRNA negative whereas ts463 is RNA positive. Two mutants of P genes were also analysed and we discuss the relationship existing between the synthesis of the three RNA species especially between poly A and non poly A cRNA.