FIG. 1.

Time course of EUO gene transcription and EUO protein synthesis in C. psittaci 6BC. (A) Northern blot. RNA was isolated with TRIzol reagent from uninfected L cells, whole infected L cells (RB) at the times indicated, and purified EBs harvested at 48 h p.i. The sample load was adjusted so that the amount of chlamydial rRNA in each lane was roughly the same. The blot shown was first reacted with a mixture of MOMP and EUO probes, exposed to film, and photographed and then stripped and reacted with the rRNA probe. The arrows at the right indicate signals to rRNA, MOMP (two transcripts at 12, 20, and 24 h p.i.), and EUO. At early times p.i. the amount of host RNA in the samples, particularly 18S rRNA, was sufficient to show cross-reaction with the chlamydial 16S rRNA. The length of the EUO transcript was estimated from unlabeled RNA standards (not shown) to be about 800 bases. (B) Immunoblot. C. psittaci RBs and EBs were harvested and partially purified at the times indicated, as described in Materials and Methods. The upper portion of the blot was reacted with C. trachomatis rabbit anti-MOMP, and the bottom portion was reacted with rabbit anti-rEUO protein.