INTERLEUKIN GENE-EXPRESSION IN MOUSE PREIMPLANTATION DEVELOPMENT

Control of growth and differentiation during mammalian embryogenesis i s regulated by growth factors from embryonic and/or maternal sources. Cytokines are polypeptide growth factors that are released by a variet y of activated immune and nonimmune cells. To identify novel members o f the cytokine family that could be involved in the growth and differe ntiation of the preimplantation embryo, we studied the expression patt ern of several genes encoding cytokines and their receptors during mou se preimplantation development in vitro. We found that poly(A)(+) mRNA s for IL-1, IL-3, IL-6, IL-7, and TNF alpha are differentially express ed at several stages of mouse preimplantation development, including u nfertilized oocytes. Immunostaining of preimplantation embryos using m onoclonal antibodies specific for several cytokines and their receptor s revealed that at least some of these mRNAs are translated into matur e proteins during preimplantation development (IL-1, IL-6, and TNF alp ha). Positive staining for IL-1 and IL-6 receptors was also detected a t these stages of development. The controlled expression of these ''in flammatory-type'' cytokines and their receptors suggests a role for th ese growth factors during the early phases of mouse ontogeny.