摘要：
Preimplantation development is critical for successful implantation and pregnancy. In the mouse preimplantation embryo, the first event of morphological and cellular differentiation is established during polarization and compaction at the 8-cell stage. The considerable cell surface and cytoplasmic changes and formation of different populations of cells at the 8-cell stage are fundamentally important for the development of all organisms. To determine genes that are specifically expressed at this crucial stage of embryo development and also to shed light on the different mechanisms that could be of importance during embryo development, we investigated mouse 8-cell and 4-cell embryo stage-specific genes using Digital Differential Display (DDD). The 8-cell stage-specific genes were sorted according to their ontology data from the Database for Annotation, Visualization and Integrated Discovery (DAVID), which outlines possible roles for the genes expressed at the 8-cell stage. This study highlights how online tools can be used to identify genes involved in embryo development. Identification of the 8-cell embryo stage-specific genes would open new opportunities for understanding molecular networks during the mid-preimplantation gene activation. Using bioinformatic tools, such as Digital Differential Display and DAVID, it will be possible to identify genes expressed at the 8-cell stage that are likely to be involved in mammalian preimplantation embryo development. Our results may provide a new foundation for molecular control at the onset of embryonic development in mammals, and should be of interest to the scientific community.
摘要：
Improvement of animal embryo sexing depends upon high-titer serologically detected male (SDM) antibody fragments. SDM sera collected from isogenic C57BL/7 female mice after inoculation with male spleen cells were characterized and used for construction of a recombinant Fab antibody library against SDM antigen, and used for analysis of the binding capacity and specificity to SDM antigen. The heavy-chain Fd and full-length light-chain K were amplified by RT-PCR from a mouse (#6) that'ed high-titer antiserum. The amplified product was inserted into the pComb3 vector followed by co-infections with the help phage VCSM 13 for construction of the phage library, which gave 1.5 x 10(7) colonies with the titer of 3.2 x 10(11) pfu/ml by a recombination rate of 80%. Sequence analysis of the PCR products of plasmid DNA of E5 clones showed that V-H and V-k had common characteristics shared by other known variable region of antibodies. The Fab antibody libraries against SDM antigen were enriched by three cycles of affinity enrichment with male spleen cells, and two cycles of non-specific absorption with female spleen cells. The ELISA results showed that 9 of 15 clones had binding capacity to the SDM antigen. This is the first report on a phage display library of SDM antigen. The mouse Fab antibody library could be used for identifying SDM antigen, and for the development of sex determination of early embryos in mammals. (C) 2007 Elsevier B.V. All rights reserved.
