Congression of unlinked markers and genetic mapping in the transformation of Bacillus subtilis 168

A thorough examination of cotransformation of two unlinked genetic markers in Bacillus subtilis 168 shows that the two recombinational events do not occur randomly. The cotransformation frequency is dependent on the distance between the two markers as well as on the order in which they replicate in the competent cell. These results indicate that uptake and/or integration of DNA molecules bearing these genetic markers is enhanced at the time these markers replicate in the competent cell.