Two species of full-length cDNA are synthesized in high yield by melittin-treated avian retrovirus particles.

A method of activating endogenous cDNA synthesis in avian retroviruses that results in the formation of two species of full-length cDNA in high yield is described. Tests of biological activity show infectivity of at least the same order of magnitude as for full-length cDNA made by other procedures. Melittin, the major component of bee venom, is used as an alternative to nonionic detergents to make the viral envelope permeable and thus activate the endogenous RNA-dependent DNA polymerase. This compound is a toxic peptide known to interact with phospholipid membranes. It appears to be less disruptive to the viral structure than detergents, resulting in a more efficient transcription of the viral genome. Preliminary tests indicate that this method will also prove useful for studying enzymatic activities associated with other enveloped viruses.