| Abstract: | Pregnancy between different species is one of the key steps to interspecific somatic cell cloning. Although interspecific clone embryos have been constructed, they could not develop to birth after being transferred to recipients. In order to clarify the mechanism of this phenomenon, interfamily pregnancy between golden hamste (Mesocricetus auratus) and mouse (Mus musculus) was studied. Co-culture results indicated that the adhesion ratios of golden hamster blastocysts on mouse uterine epithelia monolayer 12, 24, 48 and 72 h after co-culture were all significantly lower than those of mouse blastocysts. The outgrowth ratios of golden hamster blastocysts on mouse uterine epithelia monolayer 48, 72 h after co-culture were both significantly lower than those of mouse blastocysts (P < 0.01). Golden hamster's blastula could be implanted and develop to D 11 of pregnancy after being transferred to mouse uterus (the 7th day after embryo transfer). Compared to the transfer of mouse embryo to mouse uterus, the successful ratio of interfamily embryo transfer was lower and the bulk of fetus was smaller than that of intraspecific fetus. Compared to intraspecific pregnancy of mouse, the remote decidual tissue of interfamily pregnancy on D8 is looser. At the same time, expressions of CD57 and CD 68 in remote deciduas were both higher than those in the secondary deciduas in both intraspecific and interfamily pregnancy. However, expressions of the two molecules in interfamily pregnancy were lower than those in intraspecific pregnancy. These results showed that interfamily pregnancy could be established between golden hamster and mouse. But the development of fetus in interfamily pregnancy was slower than that in intraspecific pregnancy. The expression difference of CD57 and CD68 indicates the difference of immunoreaction between interfamily and intraspecific pregnancy, which may be one of the reasons leading to interfamily pregnancy termination. |
