Organoids simulating the bovine oviduct mediate the embryo-maternal interface via extracellular vesicle-transmitted signaling.

study questionDoes the implementation of a three-dimensional (3D) organoid model system that stably emulates some key functional, structural, and biological complexities of the oviduct provide a favorable apical environment for the production of extracellular vesicles (EVs) that exert an influence on early embryo development SUMMARY ANSWER: Our findings show that WHAT IS KNOWN ALREADY: Recapitulating the maternal contribution that persists during preimplantation embryonic development STUDY DESIGN SIZE DURATION: Over a 2-year period, resected ovaries from intact reproductive tracts (n = 10; a pool of two bovine animals per replicate) containing both complete contralateral and ipsilateral oviducts from assessed stage II, diestrus tracts were processed for the generation of oviductal organoids. Afterward, enriched oEVs from 3D organoids and PARTICIPANTS/MATERIALS SETTING

methodsOrganoids were characterized by light microscopy, gene expression, immunofluorescence, and 3D reconstruction, as well as histological two-dimensional (2D) cross-sectioning. Enriched oEVs from conditioned organoid culture media and OF were characterized using transmission electron microscopy, nanoparticle tracking analysis, and western blotting. Following the establishment of a stable oEV production system, bovine zygotes were divided into five groups [38.5°C Control, 41°C Control, 41°C N-EVs (oEVs derived from organoids cultured under thermoneutral conditions), 41°C S-EVs (oEVs derived from organoids cultured HS conditions), 41°C Ovi-EVs (oEVs collected from diestrus OF)] and cultured until the blastocyst stage. Following the presence or absence of oEVs during Day 1 to Day 3 of MAIN RESULTS AND THE ROLE OF CHANCE: Here, we employed a 3D culture system to generate oviductal organoids to mimic the maternal environment's response to HS and for the production of LARGE SCALE DATA: N/A. LIMITATIONS REASONS FOR CAUTION: This was an WIDER IMPLICATIONS OF THE

findingsThese results provide an uncharted attempt at recapitulating embryo-maternal nano-communication through the means of oEVs secreted from 3D oviductal organoids cultured STUDY FUNDING/COMPETING INTERESTS: This study was supported by the United States Department of Agriculture through a NIFA-AFRI Predoctoral Fellowship awarded to N.G.M. (Grant Number 2023-67011-40511), as well as funds from the College Research Council, Office of the Vice President for Research at Colorado State University. The authors attest that there are no competing interests that could have influenced the conduct or outcomes of this research.