RESUMEN
The role of the Major Histocompatibility Complex class I (MHC-I) genes in human and mouse preimplantation embryo development has received considerable attention. In contrast, information concerning the role of these genes in bovine embryo development is limited. The objective of the current study was to characterize the expression pattern of MHC-I genes during preimplantation embryo development in cattle. To this end, bovine oocytes were harvested from slaughterhouse ovaries, matured, fertilized and cultured in vitro. Samples were collected at immature and mature oocyte, presumptive zygote, 2-4-cell embryo, 8-16-cell embryo, morula, blastocyst and hatched blastocyst stages of development. MHC-I expression was detected using quantitative real-time-PCR, cDNA sequencing, whole mount immunocytochemistry and Western blotting. We report classical and non-classical MHC-I mRNA expression in bovine oocytes and developing embryos. Furthermore, we report that the pattern of MHC-I mRNA expression across development was gene- and stage-specific.