Targeted disruption of the mouse phospholipase C beta 3 gene results in early embryonic lethality

In order to investigate the biological function of phosphatidylinositol-spe cific phospholipase C (PLC) we generated mutant mice by gene targeting. Hom ozygous inactivation of PLC beta(3) is lethal at embryonic day 2.5. These m utants show poor embryonic organization as well as reduced numbers of cells , Identical phenotypes were recorded in homozygous mutants generated from t wo independently targeted embryonic stem cell clones. Heterozygous mutant m ice, however, are viable and fertile for at least two generations. We also showed that mouse PLC beta(3) is expressed in unfertilized eggs, 3-cell and egg cylinder stages of embryos. In conclusion, these results indicate that PLC beta(3) expression is essential for early mouse embryonic development. (C) 1998 Federation of European Biochemical Societies.