['To investigate the effect of increased fucosyltransferase VII (FUT7) on sialyl Lewis X (sLeX) synthesis and their impact on embryo implantation.', 'Cell and animal study.', 'Liaoning Provincial Core Lab of Glycobiology and Glycoengineering, Department of Biochemistry and Molecular Biology, Dalian Medical University.', 'Adult female mice of Kunming species.', 'A pIRES2-EGFP-FUT7 expression plasmid containing full-length human FUT7 cDNA was constructed and transiently transfected into RL95-2 or injected into the uteri of early pregnant mice. Control subjects received the mock pIRES2-EGFP or anti-sLeX antibody.', 'The expression of FUT7 and sLeX was detected by reverse transcriptase polymerase chain reaction (RT-PCR) and indirect immunofluorescence. The embryo adhesion rate was assayed in vitro with the cocultured RL95-2 and JAR implantation model. In vivo embryo implantation was investigated using a mouse model.', 'Expression of FUT7 was significantly increased after transfection of pIRES2-EGFP-FUT7 into RL95-2 cells compared with the parental control and mock vector transfectants, as demonstrated by fluorescent microscopy and RT-PCR. Expression of sLeX was also increased in FUT7 overexpressers, as detected by indirect immunofluorescence. Consistent with the elevated expression of FUT7 and sLeX, embryo adhesion rate and embryo implantation competence were significantly increased (P<.01) in both in vitro and in vivo models.'] Does overexpression of fucosyltransferase VII ( FUT7 ) promote embryo adhesion and implantation?