TcCRT+/– mutant parasites are stable after prolonged infection in mice.

<p>(A) Schematic representation of the TcCRT genomic locus in TcCRT+/– parasites (B) PCR analysis carried out from genomic DNA of TcCRT+/– and wild type parasites recovered from hemocultures of chronically infected mice. Primers: Pair CRT1-CRT2 and H1-H2 amplify the TcCRT (1.2 KB) and HYG CDS (0.96 kb), respectively. Pair CRT7-H4 amplifies the 5' UTR of TcCRT together with a fragment of the HYG CDS (1.45 kb). Pair CRT93-H6 amplifies the 3' UTR of TcCRT together with a fragment of the HYG CDS (1.4 kb). The sizes of the fragments correspond to those predicted for the replacement of TcCRT by the HYG gene.