Female mice used were 129/SvImJ wildtype (Jackson Lab), 10-16 weeks of age. 14 days after ovariectomy, mice were injected subcutaneously with progesterone dissolved in sesame oil (Sigma; 0.2mg/0.1mL/mouse), followed by sacrifice and removal of uterine horns at 18 hours after injection. 8 uterine horns from 4 mice were pooled to form one sample. Total RNA preparation, cRNA labeling and hybridization were performed according to recommendations by Affymetrix.
