186 THE EFFECT OF MATRIGEL ON THE DEVELOPMENT OF IN VITRO-FERTILIZED PORCINE EMBRYOS

Abstract

The application of matrix proteins to culture systems for growth of embryos is a logical extension in the quest to better simulate the in vivo culture environment. Matrigel, a commercially available extracellular matrix product containing collagen IV, laminin, entactin, and proteoglycans isolated from mouse tumor cells, has been tested. Development of mouse pre-implantation embryos cultivated in conventional culture medium was contrasted to that of embryos grown in solubilized Matrigel medium. In the solubilized Matrigel medium, in vitro blastocyst formation and hatching were significantly enhanced over that observed in the medium alone control. Therefore, the aim of this study was to investigate the effect of solubilized Matrigel on the development of porcine embryos after in vitro fertilization. In vitro-matured oocytes were fertilized in mTBM medium with fresh spermatozoa for 6 h. Putative zygotes were cultured in PZM-3 medium supplemented with (matrigel group) or without (control group) 0.8% Matrigel for 6 days. The number of cells in blastocysts was determined by staining with Hoechst 33342. Assessment of apoptosis in blastocysts was examined by TUNEL. The statistical significance of the data was analyzed using chi-square test and Student's t-test. The addition of Matrigel appeared not to increase the proportion of blastocysts (control: 71/219, 21.8 ± 2.2% vs. Matrigel: 69/220, 23.5 ± 5.8%). However, the mean cell numbers were significantly increased by Matrigel (Matrigel: n = 31, 52.9 ± 18.1 vs. control: n = 30, 42.3 ± 14.4; P < 0.01). The proportion of apoptotic cells was significantly lower in the Matrigel group (Matrigel: 4.5 ± 4.2% vs. control: 6.6 ± 5.5%; P < 0.05). In this experiment, Matrigel appeared to increase blastocyst quality of porcine embryos. Results suggest that Matrigel, as an extracellular matrix component, may be another avenue for formulating more physiological culture systems.