SUMMARY: Diphasic Salmonella strains, TM2, sw803 and their derivatives differing in flagellar shape and antigen type, were found to produce copolymer segments of phase-1 and phase-2 flagellins among flagella in phase 2, except for a strain which is non-flagellate in phase I. The copolymer segments were not detected in phase-I clones of any of the strains. The wave-forms of the copolymers are homologous with those of the copolymer filaments obtained by reconstitution of the corresponding phase-1 and phase-2 flagellins. Thus, in the mutant producing normal flagella in phase 1 and straight ones in phase 2, copolymer segments with curly or small waves appear among the straight filaments.

Formation of the copolymers was attributed to temporary derepression of the structural gene for phase-1 flagellin, in phase 2. Copolymerization occurred in a fraction of the phase-2 cell population at late exponential and early stationary phase in nutrient broth cultures. When a phase-2 cell was temporarily derepressed, the copolymers formed almost simultaneously in every growing flagellar filament of the cell. Their formation continued for a short period until the supply of phase-1 flagellin was exhausted after re-establishment of repression. This period was estimated to be 7.7 min on average, fluctuating between 4 and 13 min in a cell population of a straight flagellar mutant whose generation time was 55 min in late exponential phase.


Article metrics loading...

Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error