Time-course analysis of the trapped genes RNA (50, 134, and C) after exposure of parental TF-1 cells to different cytokines.

RNA was obtained from TF-1 cells starved for 4 hours and stimulated with GM-CSF, IL-3, or IL-5, according to the indicated time course. Northern blot membranes were hybridized sequentially with the³²P-labeled probes prepared for detection of 50, 134, (described in Figure 4) or C (described in “Materials and methods”). A probe of 28S RNA was used as a control to quantify the amount of RNA. Indices of modulation were calculated as a ratio of signals obtained with the specific probes versus the 28S probes, using a BIO-RAD Phosphor Analyst/PC program. Arrows represent the molecular weight markers in kilobases (kb).