Extracellular molecular response of bovine oviductal organoids to thermal stress.

The mammalian oviduct is a complex, fibromuscular organ known for its role in orchestrating a series of timely and dynamic changes to suitably support early embryogenesis. Establishing successful reproductive outcomes are largely determined through effective and cohesive communication systems between the transient embryo and the maternal environment. Climate change-induced, Heat stress (HS), is one of the largest single stressors compromising reproductive function. Systemic changes in the redox status of the maternal environment, adversely affect fertilization and early embryonic development, negative causation of HS. Oviductal organoids represent a 3-dimensional, biomimetic model to study the physiological impact of HS on the physiology of the oviduct and the subsequent developing embryo. In this study, we aimed to generate a robust bovine oviductal organoid culture system to decrypt the oviducts' differential response to HS in terms of secreted EV-miRNome, to elucidate the impact of thermal stress on oviductal physiology with subsequent potential impacts on early embryo development. The proposed research utilized the bovine species as a large animal model to study EV-mediated response of oviductal organoids to thermal stress. Bovine reproductive tissues, readily obtained from a local slaughterhouse were utilized to establish a BOEC organoids for the production of extracellular vesicles to study the physiology of the oviduct under HS and the potential embryo-maternal signals shuttled through the oviduct microenvironment. Oviductal organoids cultured under normal (37 °C) or heat stress (42 °C) conditions and EVs were isolated from the culture media for RNA isolation and small-RNA sequencing.