Maternal immune response to allogeneic embryos

ended

High embryonic mortality at the peri-implantation period (70%) is accounted after pig embryo transfer (ET), which is almost double than that of natural breeding or artificial insemination (AI). Since pregnancy is an interesting immunological paradox, our starting hypothesis is that the mechanisms regulating the maternal immune response to the embryos may be less efficient in the case of ET pregnancies, where the transferred embryos are allogeneic (e.g. contain paternal and maternal material unrelated to the recipient mother) than after natural breeding or AI, where only paternal material is unrelated to the mother (semi-allogeneic). This difference could be behind the increased embryonic death. The project will study transcriptomic and cytokine changes of porcine endometrial tissue in the presence of semi-allogeneic and allogeneic embryos during the peri-implantation period and also in the placenta of healthy and arrested fetuses. The results of the project will unveil mechanisms behind embryo-maternal dialogue. This fact is relevant in view of the necessary implementation of emergent breeding technologies, as embryo transfer (ET), for supporting sustainability and competitiveness of the European pig sector. EU is currently second biggest pig producer in the world and the largest exporter of antibiotic- and residue-free pig products derived from animals raised on highest welfare standards and with the highest genetic value. The understanding of embryo-maternal dialogue under allogeneic environments might be determinant to implement new strategies to increase the reproductive performance after ET not only in pigs but also, comparatively, in other livestock species and even in humans, where the use of donor oocytes for IVF is currently increasing. This project, with a focus on pregnancy immunological regulation, is of utmost interest for the EU goals, contributing to determine which factors still jeopardize full fertility and prolificacy when applying ET technology.