RETREG2 and cyst: To address if the limited recovery of MAG1 and MAG2 within bradyzoite cysts could have been due to mScarlet binding to immobile structures within the cyst, a bradyzoite-specific secreted form of mScarlet was constructed by ligating mScarlet to the promoter and signal peptide of CST1 (Cyst-matrix-mScarlet) and expressed within Pru.