Segregation of Unselected Markers in Mycobacterial Recombinants

Abstract

Analysis of linkage and segregation of unselected markers was made using a recombination system of Mycobacterium smegmatis strains, Jucho and Lacticola. It was demonstrated that recombinants primarily possessed the genetic characters derived from Jucho. This suggested that strains Lacticola and Jucho did not play equivalent roles in zygote formation, and that zygotes were made up essentially of the chromosome from Jucho and contained only a segment of the chromosome from Lacticola. The ordering of the genes in strain Lacticola might be as follows: φrb, gly-2⁺, leu-7⁺, and str-9. Results of backcrosses of recombinants with parental strains showed that there were four different mating types in the recombinants. This indicated that at least two different factors controlled mating in mycobacteria. D4 phage and phage Rabinowitschi did not have mating type specificities.