First Author | Rosenberg RD | Year | 1995 |
Journal | Thromb Haemost | Volume | 74 |
Issue | 1 | Pages | 52-7 |
PubMed ID | 8578517 | Mgi Jnum | J:29018 |
Mgi Id | MGI:76548 | Citation | Rosenberg RD (1995) The absence of the blood clotting regulator thrombomodulin causes embryonic lethality in mice before development of a functional cardiovascular system. Thromb Haemost 74(1):52-7 |
abstractText | We have targeted the murine thrombomodulin (TM) gene in embryonic stem cells and generated embryos as well as mice with TM deficiency. The heterozygous TM-deficient (TM+/-) mice as compared to wild-type (TM+/+) littermates exhibit 50% reductions in the levels of TM mRNA and TM protein. However, TM+/- mice appear normal and are free of thrombotic complications. The homozygous TM-deficient (TM-/-) embryos die before E9.5. An overall retardation in growth and development of TM-/- embryos is first evident on E8.5 (8-12 somite pairs). However, no specific pathologic abnormalities are observed. These initial changes take place at a time when TM is normally expressed in the endoderm of the parietal yolk sac. The removal of E7.5 TM-/- embryos from maternal decidua and their subsequent culture in vitro allows development to proceed to stages not observed in vivo (13-20 somite) with the appearance of normal blood vessels in the visceral yolk sac and embryo. The results of our studies suggest that the failure of TM-/- embryos to survive at mid-gestation is a consequence of dysfunctional maternal-embryonic interactions caused by the absence of TM in the parietal yolk sac and demonstrate that the receptor is necessary for normal embryonic development in utero. |