Figure 3.
Sporulation in C. perfringens. Working through unidentified intermediates, the Agr quorum sensing system and CcpA affect Spo0A expression or, possibly, phosphorylation to initiate sporulation. This triggers a cascade of sigma factors where SigF controls production of the three other sporulation-associated sigma factors. Two of these sigma factors (SigE and SigK) then regulate CPE production during sporulation. Compiled from (28, 29, 31, 44). Not shown in this drawing, SigE (and possibly SigK) can also regulate production of TpeL toxin (97).