Figure 4.

In situ hybridization using D3 antisense, sense, or actin antisense probes on sections of a uterine implantation site on day E9. (a) Composite autoradiograph of adjacent longitudinal sections hybridized with the probes indicated. Section 1 represents the most peripheral section, whereas section 7 is through the midportion near the implantation site. Sections are oriented so that the mesometrial surface of the uterus is toward the top. (b) Photomicrograph of section 6 probed with the D3 antisense probe. Darker portions indicate the location of silver grains deposited by the photographic emulsion at the sites of D3 antisense probe hybridization. Boxes indicate the regions viewed under higher magnification in d and e. (c) Photomicrograph of a section adjacent to that shown in b probed with the D3 sense probe. (d) Dark-field photomicrograph of the mesometrial decidual region from the section in b. White dots represent light scatter from the silver grains deposited at the sites of D3 antisense probe hybridization. (e) Dark-field photomicrograph of the decidual region abutting the uterine lumen from the section in b. Arrows point to silver grains specifically deposited over the uterine glands. No signal is apparent in the epithelial cells lining the uterine lumen (arrowheads). (f) Higher-powered light-field photomicrograph showing silver grains specifically deposited over the uterine glands in the section shown in b and e and hybridized with the D3 antisense probe. aMD, antimesometrial decidua; MD, mesometrial decidua; UL, uterine lumen.