In initial experiments, in situ hybridization studies were conducted to localize IGF-I mRNA in the mouse uterus during the periimplantation period. On gestational Day 2, before embryo passage from the oviduct to the uterus, no IGF-I mRNA was detected in mouse uteri (data not shown). IGF-I mRNA was first detected at low levels in uterine stromal cells on Day 3 of gestation (Fig. 1A). On gestational Day 4, when the embryos have passed through the oviducts and are free in the uterine lumen, and on gestational Day 5, just before implantation, a weak IGF-I mRNA signal was detected throughout the uterine stroma (Fig. 1, В and C). On gestational Day 6, after the initiation of implantation, an intense IGF-I mRNA signal was detected in uterine stromal cells underlying the myometrium (Fig. ID). buy ampicillin
An intense signal was also detected in both the myometrium and in the stromal cells underlying the myometrium on gestational Day 7 (Fig. IE). No IGF-I mRNA signal was detected in luminal epithelial cells on any day of gestation tested (Days 2—7). Gestational Day 7 uterine sections hybridized with a sense IGF-I probe showed no specific IGF-I mRNA signal (Fig. IF).
FIG. 1. Cellular localization of uterine IGF-I mRNA on Days 3 through 7 of mouse gestation by in situ hybridization. A-E) Darkfield photomicrographs of longitudinal uterine sections showing cells labeled with an antisense IGF-I cRNA probe on gestational Days 3 to 7, respectively. F) Darkfield image of section shown in E hybridized with a sense IGF-I cRNA probe. White dots indicate autoradiographic grains, le, luminal epithelium; e, embryo; d, decidua; s, stroma; m, myometrium. A-F, X40 (reproduced at 66%).