Immunopositive staining for LIF protein was nondetect-able in the endometrium in four of five animals examined during embryonic diapause (Fig. 3A) and was only faintly detected in the basal portion of the uterine glands in the fifth skunk. LIF protein was first consistently detected in the early activation stage of pregnancy, at which time strong staining was observed in luminal and glandular epithelium (Fig. 3B). Positive LIF staining remained in the luminal and glandular epithelium of the uterus in all three animals examined when blastocysts were completing their preattachment development (Fig. 3D). buy yasmin online
LIF staining was weak and was restricted to the apical cytoplasm of the luminal and glandular epithelium and to luminal fluid at the time of trophoblast attachment and initial intrusion into the luminal epithelium (Fig. 3, E and G). LIF protein was not detected in the stroma of any animal but was consistently present in the myometrium of all animals during all stages of pregnancy examined. All immunopositive staining was eliminated when the anti-rhLIF antibody was preabsorbed with rhLIF (Fig. 3C) or when sections were incubated with normal goat serum in place of primary antiserum (Fig. 3, F and H).
FIG. 3. Immunocytochemical localization of LIF (red staining) in the uterus of the spotted skunk during delayed implantation and periimplantation. A) Embryonic diapause, B) early embryo activation, C) early embryo activation with primary antisera absorbed with LIF, D) full embryo activation, E) implantation, F) implantation with goat IgG, no primary antisera, G) implantation site, H) implantation site with goat IgG, no primary antisera. Bar = 40 u,m.