1. Replicating parasites within tissue cysts are bradyzoites.
Replicating parasites within tissue cysts are bradyzoites. (A) Tissue cysts containing actively replicating parasites based on the TgIMC3 labeling pattern contain organisms that label with the bradyzoite-specific surface marker TgSRS9, indicating that they are bradyzoites. (B) Parasites within tissue cysts containing actively replicating (based on TgIMC3 labeling) parasites fail to label with the tachyzoite-specific marker TgSAG1. An example of both the highest level of TgSAG1 labeling (top panel) and typical labeling (bottom panel) are shown. The top rows in panels A and B each depict week 3 cysts, while the bottom rows depict week 8 cysts. Additional images of TgSRS9 and TgSAG1 labeling in tissue cysts, including images of immature cysts (based on thin DBA-positive cyst walls) where elevated TgSAG1 intensity is observed are presented in Fig. S5 and S6 in the supplemental material.
Elizabeth Watts et al. mBio 2015; doi: /mBio