(B) Key endogenous genes controlling Golgi (sedV, geaA, hypB) or post-Golgi trafficking (rabE, ap1σ, claH) were genetically replaced by versions transcribed under the highly repressible thiAp promoter via targeted homologous recombination. In the absence of thiamine from the growth medium (derepressed conditions) the relative proteins are expressed, while upon addition of thiamine at the onset of conidiospore germination (ab initio repression) the expression of these proteins is tightly repressed. Proteins are detected by a standard western blot analysis using either anti-FLAG or anti-GFP antibodies for Golgi and Post-Golgi proteins. Equal loading and protein steady state levels are normalized against the amount of actin, detected with a specific antibody. 