Figure 1. CD127 expression in midsagittal serial sections from gd6.5 to gd12.5 B6 implantation sites.

(A) Immunohistochemistry for CD127 (upper) or DBA-lectin (lower). (B) Immunofluorescence staining of gd10.5 B6 implantation site. Detection was nuclear DNA, DAPI (blue); uNK cells, DBA lectin (green); and CD127 antibody-reactive cells (red). DBA⁺ uNK cells (brown) were present in gd6.5 DB, but none of these or other cells with a lymphoid appearance expressed detectable CD127 (A). Rare stromal cells were CD127⁺ (arrowheads). At gd8.5, the DBA⁺ uNK cell population contained infrequent, weakly stained CD127⁺ cells (arrow). At gd10.5, when uNK cells peak, many strongly stained CD127⁺DBA⁺ uNK cells (arrows) were present in DB. At gd12.5, CD127⁺DBA⁺ uNK cells remained in DB (arrows) and were now detected in MLAp. Trophoblast cells were CD127⁺DBA⁻, as shown for gd10.5 placenta (PL). Gd12.5 fetal liver (FL) was used as a positive control for CD127. Two or more viable implantation sites from each of multiple [2–5] females were studied at each gd. L, Residual uterine lumen; SA, spiral artery.