In vitro maturation using an agarose matrix with incorporated extracellular matrix proteins improves porcine oocyte developmental competence by enhancing cytoplasmic maturation.

Here, we present a novel in vitro maturation (IVM) system comprising an agarose matrix supplemented with extracellular matrix (ECM) proteins for enhanced maturation of immature oocytes within cumulus-oocyte complexes (COCs) derived from porcine medium antral follicles (MAFs). Immunocytochemical analyses of integrin subunit α2 , α5 , α6 , β1 , and β4 expression suggested that integrin α2 β1 , α5 β1 , α6 β1 , and α6 β4 play pivotal roles in IVM of porcine immature oocytes. Combinatorial supplementation of fibronectin interacting with integrin α5 β1 , collagen interacting with integrin α2 β1 , and laminin interacting with integrin α6 β1 and α6 β4 to the agarose matrix had no significant effect on nuclear maturation. However, the number of parthenogenetic embryos that developed into blastocysts increased when oocytes were matured using agarose IVM matrices supplemented with fibronectin, collagen, or laminin. Furthermore, significant increases in cytoplasmic maturation-related parameters (BMP15 level, cumulus cell expansion score, intra-oocyte ATP level, and index of cortical granule distribution) were observed in COCs matured in vitro using ECM protein-incorporated agarose matrices. Our data suggest that mature porcine oocytes with enhanced developmental competence and high-quality cytoplasm can be generated via IVM using agarose matrices supplemented with fibronectin, collagen, or laminin.