Expression of chemokine mRNAs by fetal thymi. (A) Semi-quantitative RT-PCR for mRNAs in I-A⁺ TSCs, whole dGuo-treated fetal thymus lobes, and dGuo-treated salivary gland lobes from E14.5 fetal mice. Adult TSC debris was used as positive control (PC), except adult thymocytes for CCL3, CCL9, CXCL11, CXCL16, and CX3CL1, E14.5 fetal skin for CXCL15, E14.5 fetal gut for CCL28, and adult spleen cells for CXCL7. DW indicates distilled water. Large arrows indicate molecular species that are prominently expressed at higher levels in I-A⁺ TSCs and whole dGuo-treated fetal thymus lobes than in dGuo-treated salivary gland lobes. Small arrows indicate molecular species that are detected in I-A⁺ TSCs and whole dGuo-treated fetal thymus lobes irrespective of the detected levels in dGuo-treated salivary gland lobes. (B) Real-time RT-PCR quantification of mRNA levels of chemokines indicated by arrows in panel A. Signal levels relative to HPRT levels were normalized to the levels in salivary gland. Means and SEs are indicated.