Figure 1.

Tregs fluctuate during estrus cycle peaking at estrus, time point of sexual receptivity. Determination of the estrus cycle in non-pregnant females according to cell types in vaginal smears (A). Percentage of CD4⁺Foxp3^GFP+ cells of female Foxp3^GFP mice (n = 5/cycle stage) was analyzed in vaginal lavage (B). Data are expressed as single dot plots with medians and were analyzed by Mann–Whitney-U test (*P ≤ 0.05). Snap shots of two-photon microscopy videos of Foxp3^GFP positive cells in uterus performed at different phases of the cycle (C) estrus phase; (D) diestrus phase; (E) metestrus phase; (F) proestrus phase.