Use of microarray technology to profile gene expression patterns important for reproduction in cattle.

Fertility in cattle is a major component of many agricultural enterprises and there is pressure to devise methods to improve this. A number of approaches are ongoing, one of which is to better understand the cellular and molecular events of the development of reproductive tissues and to use these as targets for developing new strategies. Microarray technologies now allow us the potential to determine the transcriptional profile of expressed genes in a given tissue. This review focuses on the types of microarrays available for studies in cattle and concludes that genes associated with one or more of the cellular processes of cell survival/death, intracellular signalling, transcription and translation, cell division and proliferation and cellular metabolism are the main transcriptional pathways that control the development of ovarian follicles, oocytes, early embryos and the uterine endometrium about the time of the establishment of pregnancy.

Regulation of non-classical major histocompatability complex class I mRNA expression in bovine embryos.

Regulation of expression of the class I major histocompatability complex (MHC class I) at the maternal fetal interface may play a critical role in embryo survival and the establishment of pregnancy in cattle. However, information concerning immunoregulation of implantation in cattle remains quite limited. Therefore, our current research is concerned with characterizing the expression and regulatory effect of a number of immune factors in the developing bovine embryo. We have analysed the effect of embryo culture in vitro (IVC) in medium supplemented with progesterone (P4): leukemia inhibitory factor (LIF), interferon gamma (IFNG), interleukin (IL)-1B, IL3, IL4, IL10 and granulocyte-colony stimulating factor (G-CSF) on in vitro embryo development and expression of the bovine non-classical MHC class I genes NC2, NC3 and N4 in blastocysts. Cytokine supplementation during IVC did not affect cleavage rate or blastocyst development. However, embryo mRNA expression of NC2, NC3 and NC4 was significantly (p≤0.05) modified in a gene- and cytokine-specific manner. Sequence analysis of the promoter regions of these genes confirmed the presence of appropriate binding sites through which the cytokine signalling could be mediated. In contrast to the lack of effect on in vitro blastocyst development, the non-classical MHC-I expression data suggests a preferential immunomodulatory role of these cytokines during preimplantation embryo development.