The high failure rate of interspecific pregnancy is a major obstacle to the successful interspecific cloning of mammals. To investigate the reasons for the failure of inter-specfic pregnancy between rats and mice, we ...The high failure rate of interspecific pregnancy is a major obstacle to the successful interspecific cloning of mammals. To investigate the reasons for the failure of inter-specfic pregnancy between rats and mice, we transferred rat blastocysts into mouse uteri on the third day of pseudopreg-nancy (D3). Our previous study showed that intact rat em-bryos could still be observed in mouse uteri on D9. In the present study, we found that expression of CD57 and CD68 increased significantly at the maternal-fetal interface fol-lowing the transfer of rat embryos. Similarly, Leukaemia inhibitory factor (LIF) expression increased, but vascular endothelial growth factor (VEGF) expession decreased. In a co-culture system, the percentage of rat ectoplacental cones (EPCs) with adhesion and outgrowth and outgrowth area on mouse uterine decidual cells were less than that of mouse EPCs. These results indicate that an increase in the immu-nological rejection response and a decrease in the invasive-ness of rat embryos may be important reasons for the failure of interspecific pregnancy between rat and mouse.展开更多
Nitric oxide (NO) is a multifunctional messen-ger molecule produced through oxidation of L-arginine to L-citrulline by enzyme NO synthase (NOS). In the current study, mouse blastocysts were cultured in the different m...Nitric oxide (NO) is a multifunctional messen-ger molecule produced through oxidation of L-arginine to L-citrulline by enzyme NO synthase (NOS). In the current study, mouse blastocysts were cultured in the different media, and the implantation capacity of blastocyst was evaluated by evaluating the percentage of embryos adhesion and out-growth after culture for 12, 24 or 48 h. Matrix metallopro-teinase-2 (MMP-2) mRNA was detected by RT-PCR, and MMP-2 protein was detected by gelatin zymography. Inhibi-tion of blastocyst adhesion and outgrowth was observed in embryo cultured with 500 mmol/L NOS inhibitor NG-mono- methyl-L-arginine (L-NMMA) alone; however, 100 mmol/L S-nitroso-Nacetylpenicillamine (SNAP), a NO donor, and 20 mmol/L cGMP analogue, 8-Br-cGMP could block this inhibi-tion. The expression and production of MMP-2 in the blas-tocysts were suppressed by L-NMMA, and SNAP or 8-br-cGMP could reverse this suppression. These results suggest that NO induces embryo implantation by cGMP sig-naling pathway.展开更多
基金supported by the Special Funds for the Major State Basic Research Project(Grant No.G1999055903)the National Natural Science Foundation of China(Grant No.30170112)+1 种基金the Knowledge Innovation Project of the Chinese Academy of Sciences(Grant No.KSCX-0501)the Innovative Program of the CAS(Grant No.KSCX3-IOZ-07).
文摘The high failure rate of interspecific pregnancy is a major obstacle to the successful interspecific cloning of mammals. To investigate the reasons for the failure of inter-specfic pregnancy between rats and mice, we transferred rat blastocysts into mouse uteri on the third day of pseudopreg-nancy (D3). Our previous study showed that intact rat em-bryos could still be observed in mouse uteri on D9. In the present study, we found that expression of CD57 and CD68 increased significantly at the maternal-fetal interface fol-lowing the transfer of rat embryos. Similarly, Leukaemia inhibitory factor (LIF) expression increased, but vascular endothelial growth factor (VEGF) expession decreased. In a co-culture system, the percentage of rat ectoplacental cones (EPCs) with adhesion and outgrowth and outgrowth area on mouse uterine decidual cells were less than that of mouse EPCs. These results indicate that an increase in the immu-nological rejection response and a decrease in the invasive-ness of rat embryos may be important reasons for the failure of interspecific pregnancy between rat and mouse.
文摘Nitric oxide (NO) is a multifunctional messen-ger molecule produced through oxidation of L-arginine to L-citrulline by enzyme NO synthase (NOS). In the current study, mouse blastocysts were cultured in the different media, and the implantation capacity of blastocyst was evaluated by evaluating the percentage of embryos adhesion and out-growth after culture for 12, 24 or 48 h. Matrix metallopro-teinase-2 (MMP-2) mRNA was detected by RT-PCR, and MMP-2 protein was detected by gelatin zymography. Inhibi-tion of blastocyst adhesion and outgrowth was observed in embryo cultured with 500 mmol/L NOS inhibitor NG-mono- methyl-L-arginine (L-NMMA) alone; however, 100 mmol/L S-nitroso-Nacetylpenicillamine (SNAP), a NO donor, and 20 mmol/L cGMP analogue, 8-Br-cGMP could block this inhibi-tion. The expression and production of MMP-2 in the blas-tocysts were suppressed by L-NMMA, and SNAP or 8-br-cGMP could reverse this suppression. These results suggest that NO induces embryo implantation by cGMP sig-naling pathway.
