Blastocyst formation is a crucial stage of early embryo development.Cell junction proteins and cell adhesion associated proteins are involved in the establishment of cell junction,and subsequently induce cell compaction,blastocyst formation,differentiation of trophectoderm and maintenance of blastocyst expansion.Genes regulating development and differentiation participate in embryo development and differentiation of inner cell mass and trophectoderm,which controls the transition from the undifferentiation to differentiation state.Furthermore,cytokine and growth factor have influence on the proliferation of cells of inner cell mass.In a word,many proteins and factors are involved in the gene expression and regulation of blastocyst formation.