CONSTITUTIVE EXPRESSION OF TNF-ALPHA AND TNF-BETA GENES IN MOUSE EMBRYO - ROLES OF CYTOKINES AS REGULATOR AND EFFECTOR ON DEVELOPMENT

1. Using the RT/PCR method, we examined mRNA expression of several inf lammatory factors in mouse embryos during mid-late embryonal developme nt. mRNAs of tumor necrosis factor (TNF)-alpha, TNF-beta, their recept ors (TNF-RI, TNF-RII), transforming growth factor (TGF)-beta, were exp ressed constitutively in most of the embryonic tissues. 2. While mRNAs of other factors, interleukin (IL)-1 alpha, IL-1 beta, IL-3, IL-6, gr anurocyte-colony stimulating factor (G-CSF), leukaemia inhibitory fact or (LIF), and interferon (IFN)-gamma were only limitedly expressed. 3. The mRNAs of several complement components (C2, C3, C4, CS) and recep tors (CR1, CR2) were also detected. Among them, the expression of C3 a nd CR1 were prominent. These results strongly support our idea that in flammation-like system play an important role to regulate embryogenesi s.