Increased expression of cytokine receptor and pro-apoptotic genes during pregnancy. CD8 T cells were sorted using fluoresence-activated cell sorting from single spleens or pooled uterine draining lymph nodes (two or three mice) from unmated (UM) controls and day 5, 8 and 15 pregnant mice. RNA was prepared by Triazol extraction and analysed by quantitative reverse transcription polymerase chain reaction. Relative expression was determined by standard curve analysis and normalized by dividing by the geometric mean of two housekeeping genes. Shown is the relative expression of (a) interleukin-7 receptor α-chain (IL-7Rα), (b) IL-15Rα, (c) Fas, (d) Fas ligand (FasL), (e) Bcl-2, and (f) Bim in CD8 T cells from the spleen and uterine draining lymph nodes during pregnancy. Open bars represent spleen cells and filled bars are pooled uterine lymph node cells. Statistical significance of spleen samples was determined by one-way analysis of variance with Dunnett's post-test using UM controls for comparison *P < 0·05, **P < 0·01.