Isolation of P1cinC(+) and P1cinC(-) mutants and detection of their polypeptides involved in host specificity

P1cinC(+) mutants were isolated from a P1CMclrl00 lysogen based on the criterion that the cin mutation cannot restore flagellar phase variation of the hin pin strain, and a P1cinC(-) mutant was isolated from a P1cinC (+) lysogen of the hin⁺ pin⁺ strain by utilizing the difference in colonial types at 41°C. The hin⁺ pin⁺/P1cinC(-) strain yielded P1cinC(+) lysogens at a rate of 10^-2 per bacterium while the hin pin/P1cinC(-) strain was considerably stable. Anti-P1cinC(+) serum neutralized both the P1cinC(-) and MuG(+) particles to 16% the rate of the homologous combination whereas anti-P1cinC(-) serum neutralized the P1cinC(+) particles to 45% the rate of the homologous combination. This indicates that P1cinC(+) and P1cinC(-) bear antigenically distinct polypeptides concerned with host specificity and that P1cinC(+) shares some antigen(s) involved in infectivity with MuG(+). The analysis of whole phage proteins revealed that P1cinC(+) had a 105 kd polypeptide, and P1cinC(-) had 101 kd instead of 105 kd.