抄録
The preimplantation development still hides many secrets especially regarding the gene expression and the in vitro prepared embryos still do not reach the quality of in vivo prepared ones. Moreover, there are still not adequate techniques to evaluate developmental potential of the embryo. The quality is determined mainly based on the morphological appearance or cleavage timing. Hence there is a need for search for more precise markers. Particularly, high impact is focused on identification of genes whose gene expression could be used as marker of high developmental competence of the embryo. The candidate genes are searched based on their gene expression. The initial searching is performed using microarray analysis based on comparison of gene expression of two embryonic populations (e.g. 4- and 8-cell stage). Selected genes are then tested for mRNA expression throughout whole preimplantation development. The increase in mRNA level at the stage of embryonic genome activation (late 8-cell stage in cattle) suggests the importance of the gene. Here, I will briefly describe two of the identified genes - nucleophosmin and cullin 1. Nucleophosmin is nucleolar protein that participates especially in ribosome biogenesis and RNA processing. Its protein localization during bovine preimplantation development copies the state of formation of nucleoli. Cullin 1 is basic member of E3 ubiquitin ligase SCF complex. At the EGA stage the mRNA expression of cullin 1 switches between two genes coding transcripts with 83% homology. This suggests high importance of cullin 1 expression, however the true cause of the switch remains to be elucidated. Supported by GACR 523/09/1035; GACR 204/09/H084 and GAUK 43-251133
