Abstract: 82

MONOCLONAL NON-SPECIFIC SUPRESSOR FACTOR (MNSF): ONE OF THE GENES DOWN-REGULATED AT IMPLANTATION SITES COMPARED TO INTERIMPLANTATION SITES IN THE MOUSE UTERUS.

Gui-ying Nie¹ , Ying Li¹ , Lois Salamonsen^{1 *}, Jock Findlay^{1 *}
Prince Henry's Institute of Medical Research, PO Box 5152, Clayton, Victoria 3168, Australia ¹

Successful implantation requires synchronous development of and active dialogue between the maternal endometrium and implanting blastocyst. While it is well established that appropriate maternal steroid hormones are a necessary part of the endometrial preparation for implantation, the molecular events at the actual site of implantation are still little understood. The aims of our studies were to identify genes explicitly expressed or repressed at the sites of implantation by utilising RNA differential display (DDPCR), and to establish the roles of these genes in the implantation process in a mouse model. Ten bands unique in implantation sites compared to interimplantation sites were identified by the DDPCR and subsequently confirmed by Northern blotting. One of these bands contained a gene tag which was highly homologous to mouse monoclonal non-specific suppressor factor (MNSF) or Fau. Using this tag the full cDNA sequence of this gene was obtained by screening a lamda gt11 cDNA library, this longer cDNA was essentially the same as MNSF, except that it had much longer 5' un-translated region. Northern analysis showed that this gene was widely expressed; interestingly the expression of this gene was much lower in implantation sites compared to interimplantation sites on day 4.5 of pregnancy when embryos first attach to the uterus and initiate implantation, this down-regulation was also observed on day 5.5 of pregnancy when the implantation had well commenced. These results suggest a role for MNSF during embryo implantation and early pregnancy, possibly regulating the immune system at the maternal-fetal interface.

    This abstract is being presented on Sunday, August 1 at 8:00 AM to 10:15 AM at CUB 2nd Floor Ballroom.