No abstract

The study of uterine gene expression patterns is valuable for understanding the biological and molecular mechanisms that occur during embryo implantation. Real-time quantitative RT-PCR (qRT-PCR) is an extremely sensitive technique that allows for the precise quantification of mRNA abundance; however, selecting stable reference genes suitable for the normalization of qRT-PCR data is required to avoid the misinterpretation of experimental results and erroneous analyses. This study employs several mouse models, including an early pregnancy, a pseudopregnancy, a delayed implantation and activation, an artificial decidualization and a hormonal treatment model; ten candidate reference genes (PPIA, RPLP0, HPRT1, GAPDH, ACTB, TBP, B2M, 18S, UBC and TUBA) that are found in uterine tissues were assessed for their suitability as internal controls for relative qRT-PCR quantification. GeNormPLUS, NormFinder, and BestKeeper were used to evaluate these candidate reference genes, and all of these methods identified RPLP0 and GAPDH as the most stable candidates and B2M and 18S as the least stable candidates. However, when the different models were analyzed separately, the reference genes exhibited some variation in their expression levels.

No abstract

The aim of this study was to investigate the spatiotemporal expression and regulation of GRP78 in the mouse uterus during the peri-implantation period. The GRP78 protein was mainly detected in the luminal and glandular epithelia on days 1-4 of pregnancy. On day 5 of pregnancy, the GRP78 protein was more highly observed around the implanted embryo at the implantation site. There was no detectable GRP78 protein signal on day 5 of pseudopregnancy. GRP78 mRNA and protein levels gradually increased on days 6-8 of pregnancy, and the expression pattern was also expanded, coinciding with the development of decidua. Similarly, GRP78 expression was also strongly expressed in decidualised cells following artificial decidualisation. Compared with the results obtained with the delayed uterus, a high level of GRP78 expression was detected in the implantation-activated uterus. In the uteri of ovariectomised mice, GRP78 expression increased and reached its highest level after injection of oestrogen, and progesterone seemed to have an antagonistic effect on oestrogen up-regulation of GRP78 expression. Our data indicate that GRP78 might play an important role during the process of mouse embryo implantation, and GRP78 expression was mainly regulated by active blastocysts and maternal oestrogen.