CST9 and cyst: To characterize the role of cyst wall proteins in cyst biology, single guide RNAs (sgRNAs) targeting the N termini of CST4, CST8, CST9, and MPC3 BirA* parasites were cotransfected with donor DNA oligonucleotides into their respective endogenously BirA*-tagged parental strains using a deletion strategy described previously (14).