Figure 2.

Expression of Fas/FasL protein in mouse mammary tissue. Western blot analysis for Fas and FasL was performed with protein samples obtained from the same samples described in Figure 1. Fas expression is found in breasts from virgin mice but is not expressed during pregnancy and lactation. High levels of Fas protein appear 1 day after weaning. FasL is expressed during pregnancy, lactation, and involution, but not in the virgin mouse. The intensity of the signal was analyzed using a digital imaging analysis system. Bars represent the average ± SD from three independent experiments. The figure of the immunoblot is a representative experiment of the three experiments. Lane 1, virgin; lane 2, day 15 of pregnancy; lane 3, day 19 of pregnancy; lane 4, day 10 of lactation; lane 5, day 1 AW; lane 6, day 2 AW; lane 7, day 4 AW; lane 8, day 12 AW.