Reproduction Abstracts

Introduction: Immune tolerance at the feto–maternal interface must be established during the processes of implantation and pregnancy. Monoclonal nonspecific suppressor factor beta (MNSFβ) is a secreted protein that possesses antigen-nonspecific immune suppressive function. The objective of this study was to establish the MNSFβ gene knockout mouse model, observe and analyze its reproductive phenotypes to further explore the roles of MNSFβ played in mouse embryo implantation and pregnancy.

Materials and methods: The MNSFβ gene knockout mice were constructed by the Cre/loxP system. The mice phenotypes were identified by PCR, western blot and immunohistochemical methods.

Results and discussion: The MNSFβ heterozygous mice (MNSFβ^−/−), but not the MNSFβ homozygous mice (MNSFβ^-/-), were obtained through MNSF^flox/flox mice mated with EIIa-cre transgenic mice. MNSFβ^−/− murinereproductivity reduced and sex imbalance occurred possibly resulted from preferential fetal lethality in female offsprings. Expression of MNSFβ protein was barely detected in the MNSFβ^−/− murine thymus tissues. Further flow Cytometry analysis showed that, the distribution pattern of several immune cells and immune cells secreting four cytokines could not be affected by the MNSFβ gene excalation. In an in vitro co-culture model of ICR mouse blastulas and MNSFβ^± mouse endometrial stromal cells, it was found that the MNSFβ gene excalation could delay the time and process of the mouse blastulas implantation. So, it was proposed that MNSFβ gene was required for normal fertility and fecundity.