RNA recombination: --introducing poly(A) into Q beta phage.

Poly(A) molecule is inserted between two Q beta RNA molecules which have been partially degraded, one from the 3'-end and another from the 5'-end. E. coli HfrH is infected with these mosaic RNA molecules and a few recombined phages carrying poly(A) are obtained. Analysis of the RNA of 907 phage (one of these recombination phages) shows that the chain length of the poly(A) it contained is about 40.