Dawit Tesfaye

Associate Professor-ARBL Large Animal Reproduction Biomedical Sciences

About Dawit

Research in my laboratory focuses on 1) Identification of genes and gene regulatory molecules associated with oocyte maturation and early embryo development with special emphasis on bovine, 2) investigating the role of extracellular vesicle coupled miRNAs and proteins in oocyte and embryo development and 3) Functional analysis of genes and regulatory miRNAs in various reproductive cells, oocytes and preimplantation embryos. My lab investigates the molecular mechanisms regulating female fertility in cattle with special emphasis on gene and gene regulatory mechanisms associated with oocyte maturation and preimplantation embryo development. Embryos response to various culture conditions (in vitro or in vivo) or environmental stressors with respect to transcriptome and epigenome modulation was the focus of my research in the last decade. Recent researches in my lab focuses on understanding the mechanisms behind embryos survival under suboptimal environmental conditions. The most significant contribution of my research in the last years is the identification of the NRF2-mediated oxidative stress response as a dominant pathway playing a role in the survival of bovine embryos under suboptimal or harmful conditions. Presently, we are using various genetic and pharmacological approaches to modulate the NRF2-mediated oxidative stress response in preimplantation embryos. For this we use state-of-the-art CRISPR-cas9 and siRNA to knockdown the KEAP1 gene, which is the cytoplasmic inhibitor of NRF2 in bovine oocytes and embryos to increase the availability of NRF2 protein and subsequent transcription of antioxidant enzymes. Moreover, various compounds with antioxidant capacity will be utilized to enhance the survival of preimplantation embryos under various suboptimal conditions. The research results from my lab are expected to contribute to the development of molecular markers for oocyte and embryo developmental competence and improving embryos survival in Assisted Reproductive Technology (ART) procedures in cattle with potential translation to humans.

Education

Ph.D., University of Bonn, Germany, 2004M.Sc, University of Bonn, Germany, 2000B.Sc., Haramaya University of Agriculture, Ethiopia, 1990

Publications

Mikhael Poirier, Dawit Tesfaye, Tsige Hailay, Dessie Salilew-Wondim, Samuel Gebremedhn, Franca Rings, Christiane Neuhof, Karl Schellander & Michael Hoelker (2020): Metabolism-associated genome-wide epigenetic changes in bovine oocytes during early lactation. Nature Scientific Reports. 10:2345 Omar Khadrawy, Samuel Gebremedhn, Dessie Salilew-Wondim, Franca Rings, Christiane Neuhoff, Michael Hoelker, Karl Schellander, Dawit Tesfaye (2020): Quercetin supports bovine preimplantation embryo development under oxidative stress condition via activation of the Nrf2 signaling pathway. Reproduction in Domestic Animals. In press.Dawit Tesfaye, Tsige Hailay, Dessie Salilew-wondim, Michael hoelker, Simret Bitseha, Samuel Gebremedhn (2020): Extracellular vesicle mediated molecular signaling in ovarian follcile: Implication for oocyte developmental competence. Theriogenology, 150:70-74.Taqi MO, Saeed-Zidane M, Gebremedhn S, Salilew-Wondim D, Khadrawy O, Rings F, Neuhoff C, Hoelker M, Schellander K, Tesfaye D. (2019): Sexual dimorphic expression and release of transcription factors in bovine embryos exposed to oxidative stress. Mol Reprod Dev. September 22.Hailay T, Hoelker M, Poirier M, Gebremedhn S, Rings F, Saeed-Zidane M, Salilew-Wondim D, Dauben C, Tholen E, Neuhoff C, Schellander K, Tesfaye D. (2019): Extracellular vesicle-coupled miRNA profiles in follicular fluid of cows with divergent post-calving metabolic status. Nature Scientific Report. Sep 6;9(1):12851.

Research Specialty

Reproductive Biology- Molecular regulation of early embryo development