| Abstract: | MX belongs to a family of type I interferon (IFN)-stimulated genes, and the MX protein hasantiviral activity. MX has at least two isoforms, known as MX1 andMX2, in mammals. Moreover, bovine MX1 has been found to have alternativesplice variants—namely, MX1-a and MX1B. In ruminants, IFN-τ—a type I IFN—istemporarily produced from the conceptus before implantation and induces MX expression in theendometrium. However, the expression dynamics of MX after implantation are not clear. In thepresent study, we investigated the expression of MX1-a, MX1B andMX2 in the endometrium and placenta before and after implantation along with the expressionof IFN-α, type I receptors (IFNAR1 and IFNAR2) andinterferon regulatory factors (IRF3 and IRF9). Pregnant uterine samples weredivided into five groups according to pregnancy days 14–18, 25–40, 50–70, 80–100, and 130–150. Tissue sampleswere collected from the intercaruncular endometrium (IC), caruncular endometrium (C) and fetal placenta (P).Although all the MX expressions were significantly higher in the IC and C at days 14–18,presumably caused by embryo-secreted IFN-τ stimulation, their expressions were also detectable in the IC, Cand P after implantation. Furthermore, IFN-α expression was significantly higher in the IC.RT-PCR indicated IFNAR1, IFNAR2, IRF3 andIRF9 mRNA in all the tissues during pregnancy. These results suggest that all theMX genes are affected by the type I IFN pathway during pregnancy and are involved in animmune response to protect the mother and fetus. |
