Figure 2.

Expression of cpn60 at different stages in the G. lamblia life cycle. (A) Northern blot analysis of total cellular RNA using a PCR fragment of the G lamblia cpn60 as a probe. Expression of the ≈1.8-kb cpn60 transcript was monitored in the vegetative trophozoite (T) stage, and after 5, 24, and 48 hr of encystation of G. lamblia. (B) Western blot analysis of total cellular protein isolated at different stages of encystation and excysation using a Synechococcus sp. anti-cpn60 antibody. Levels of the ≈60-kDa putative cpn60 protein were constant during the transition from the trophozoite stage (T) and throughout 0–66 hr of encystation. This protein was also present in the cyst phase (C) and after the first stage of induction of excystation (pI). A marked decrease in cpn60 protein was observed after the second stage of encystation (pII). Low levels of cpn60 persisted at 20 min, 90 min, 1 day, and 3 days after excystation, increasing after 6 days.