Using green fluorescent protein (GFP) as a marker of bradyzoite differentiation (by virtue of GFP expression driven by the bradyzoite-specific LDH2 promoter in the PruΔku80 strain [18]), MYR1 was shown to be expressed and secreted by these in vitro-derived bradyzoites upon infection of new host cells under bradyzoite-inducing conditions, at both 1 and 4 days p.i. (Fig. 1C). This evidence concerns the gene MYO1B and infection.