2 INSERTIONS IN GALACTOSE OPERON HAVING DIFFERENT SIZES BUT HOMOLOGOUS DNA SEQUENCES

DNA from λdg phages carrying the strong-polar insertions N 102 and N 116 was transcribed into RNA in vitro. The RNA was exhaustively hybridized to λdg-DNA carrying the wildtype galactose operon. The remaining RNA contained a fraction which specifically hybridized to DNA carrying the insertion. The insertion-specific RNA hybridizes equally well to both insertions, regardless from which insetion the RNA was transcribed. The amount of insertion-specific RNA transcribed from the larger insertion N 102 is 2-3 times larger than the amount transcribed from insertion N 116. © 1969 Springer-Verlag.