RECOMBINATION BETWEEN THE INFLUENZA VIRUS STRAINS WSE AND CAM.

Recombination between the A prime strain CAM and the influenza A strain WSE gave rise to the forms CAM+ and WS -- corresponding to an interchange of characters formulated as A'bD-FCE+abd-fce→ A'bD-fee and abd-FCE. A very small yield only of recombinants was obtained. Back recombination, according to the scheme A'bD-fce+abd-FCE→ abdfce+A'bDFCE, occurred readily, giving a high yield of both original forms. A variety of WS derivatives showing varying degrees of loss of virulence for the mouse lung and/or the chick embryo were obtained in these interactions. [ABSTRACT FROM AUTHOR]