Serial Analysis Of Gene Expression In Mouse Uterus At Implanttion Site

Implantation is a complex interaction between the uterus and blastocyst. A lot of genes are imvolved in embryo-uterine interactions during implantation. Oligonucleotide chips, cDNA microarrays, differential display RT-PCR and other approaches have been used to screen implantation-related molecules. To identify implantation-related genes and novel pathways during implantation, the differential gene expression between inter-implantation site and implantation site in mouse uterus on day 5 of pregnancy was profiled by serial analysis of gene expression (SAGE). The SAGE libraries of 10 bp tags constructed from mouse uteri at inter-implantation site and implantation site were deposited in the GEO repository. The total numbers of tags sequenced were 51,306 tags for inter-implantation library and 53,214 tags for implantation library, corresponding to 16,964 and 16,733 unique tags, respectively. In order to increase the percentage of the tags with single match, we also used the same sequence files of SAGE libraries to construct two SAGE libraries of 11-bp tags. The total numbers of tags in 11-bp libraries were 48,121 for inter-implantation site and 50,227 for implantation site, corresponding to 16,677 and 16,696 unique tags, respectively. There were 1,039 tags specifically expressed at inter-implantation site, and 1,252 tags specifically expressed at implantation site. Based on p-value, there were 195 tags significantly up-regulated at inter-implantation site and 261 tags significantly up-regulated at implantation site, of which 100 genes were single-matched at inter-implantation site and 127 genes single-matched at implantation site, respectively.In order to validate SAGE data, RT-PCR was performed to examine differential expression of 14 randomly selected tags with single match, 7 for significantly up-regulated ones and 7 for down-regulated ones. For all of the genes examined, the trend of relative expression of their transcripts was comparable between SAGE and RT-PCR. SAGE data were further confirmed by in situ hybridization. 1810014L12Rik, Psmb5, Cd63, Npm1, Fads3 and Tagln2 were shown to be highly expressed at implantation site compared to inter-implantation site. Compared to inter-implantation site, Ddx39 was strongly expressed in the subluminal stromal cells at implantation site on day 5 of pregnancy. Ddx39 expression at implantation site was specifically induced by active blastocysts. Additionally, Ddx39 expression was significantly up-regulated by...