Expression of ChM-I in the mouse uterus during early pregnancy. (A) Northern blot analysis of ChM-I mRNA in the pregnant mouse uterus. Total RNA was extracted from pregnant mouse uteri (myometrium + decidua + embryo) and non-pregnant mouse uteri, separated on a denatured agarose gel, and transferred to a nylon membrane. The blots were then hybridized with a radio-labeled probe for ChM-I, Prl8a2, TIMP-3, and VEGF-A
, respectively. The equivalent loading of RNA (15 μg/lane) in each lane was verified by ethidium bromide staining. Arrowheads indicate the positions of the 28S and 18S ribosomal RNAs. (B) Total RNA was extracted from decidua (7.5 days p.c.), non-pregnant mouse uteri (8-week-old), embryos (7.5 days p.c., including extraembryonic tissues), and placenta (13.5 days p.c.). The decidual tissues were prepared by the removal of embryos and extraembryonic tissues from whole decidual capsules. One microgram of each total RNA preparation was reverse-transcribed, and the expression of ChM-I and marker genes (Prl8a2, a marker for trophoblasts and decidua; Brachyury, a marker for embryonic tissue) was analyzed by RT-PCR (30 cycles). GAPDH was used as an internal control. The data are representative of three independent experiments.