Practice question

Differentiation-inducing factor-1 is chlorinated alkyl phenone polyketide synthesized from acetyl-CoA via polyketide synthase StlB and methyltransferase DmtA. Produced primarily by prespore cells under PKA control, DIF-1 diffuses anteriorly inducing prestalk and basal disc differentiation. It activates DimA and DimB transcription factors, elevates intracellular calcium, represses prespore genes, and induces ecmA and ecmB. DIF-deficient mutants form sparse stalks with reduced prestalk proportion. Thus DIF-1 mediates proportioning feedback where majority prespore population controls minority supporting stalk lineage, ensuring constant ratio critical for proper fruiting body architecture and efficient spore dispersal.