NORMAL-DISTRIBUTION OF TUMOR-NECROSIS-FACTOR-ALPHA MESSENGER-RIBONUCLEIC-ACID AND PROTEIN IN THE UTERI, PLACENTAS, AND EMBRYOS OF OSTEOPETROTIC (OP/OP) MICE LACKING COLONY-STIMULATING FACTOR-I

In order to map mouse tumor necrosis factor-alpha (TNF) gene expression in detail and to determine whether transcription or translation of the TNF gene is regulated by uterine colony stimulating factor-1 (CSF-1), preimplantation embryos, oviducts, uteri, and uteroplacental units were studied in various strains of mice. These included homozygous osteopetrotic (op/op) female mice, which completely lack CSF-1, and heterozygous (+/op) females, which have normal levels of CSF-1. TNF mRNA was identified in all samples except preimplantation embryos by use of Northern blot hybridization or reverse transcriptase polymerase chain reaction. In situ hybridization and immunocytochemical experiments showed that the TNF gene was expressed in mouse oviduct and uterine epithelial cells, decidual cells, macrophage-like cells, placental trophoblast, and embryos. Despite an absence of CSF-1, TNF gene expression in the uteri, placentas, and embryos of op/op mothers did not differ in any major respect from expression in +/op or other strains of mice. The results of this study therefore indicate that the TNF gene is transcribed and translated in an ordered sequence through mouse gestation, and that maternal CSF-1 is not essential to expression of this cytokine gene. Collectively, these findings are consistent with a major role for TNF in mouse reproduction and development and with a potential compensatory function for this potent polypeptide factor in CSF-1 deficiency.