Required for a general cell fate determination at the onset of development. Required for the specification of an initial population of prespore cells in which tagA is expressed. Required for normal SDF-2 signaling during spore encapsulation. Expressed in prespore and in mature spores, and at low levels in vegetative cells. Accumulates between 2 and 10 hours of development and decreases thereafter (at protein level). Down-regulated by phagocytic stimuli (when grown on E.coli). TagA mutant aggregates elaborate multiple prestalk cell regions during development and produce spores asynchronously and with low viability. They produce about twice as many prestalk cells as the wild type as judged by a prestalk cell reporter construct. When mixed with wild-type cells, tagA-cells become overrepresented in the prestalk cell population, suggesting that this phenotype is cell-autonomous. In the C-terminal section; belongs to the ABC transporter superfamily. ABCB family. Multidrug resistance exporter (TC 3.A.1.201) subfamily. In the N-terminal section; belongs to the peptidase S8 family.