EFFECT OF AMPHIREGULIN ON PREIMPLANTATION DEVELOPMENT OF IN VITRO FERTILIZED AND PARTHENOGENETIC PORCINE EMBRYOS

Abstract

Successful implantation is the result of reciprocal interactions between the implantation-competent blastocyst and receptive endometrial epithelium. Although various cellular aspects and molecular pathways of this communication have been identified, one of the proposed molecules for the successful implantation of embryos is amphiregulin (AREG) which is a member of epidermal growth factor (EGF) family and is expressed in the endometrium. The objective of this study was to investigate the effect of AERG supplementation of the in vitro culture medium on the development of porcine in vitro fertilized (IVF) and parthenogenetic embryos by evaluating the rates of cleavage rate, blastocyst formation, and blastocysts cell number. In experiment 1, IVF and parthenogenetic embryos at 1-cell stage were cultured in North Carolina State University (NCSU)-23 medium supplemented with different concentrations of AREG (0, 0.5, 5 and 50 ng/ml) for 7 days. There was no difference among all groups in the rates of cleavage and blastocyst formation. Moreover, there were no differences in the total cell number of blastocyst among the IVF and parthenogenetic embryos of 0, 0.5 and 5 ng/ml AREG groups (51.9±19.5 and 51.3±21.1, 61.8±27.8 and 59.3±27.9 and 69.5±27.6 and 56.9±30.3, respectively). However, the total cell numbers of blastocyst in the IVF and parthenogenetic embryos of 50 ng/ml AREG group was significantly higher (p < 0.05) than those of 0 ng/ml AREG groups (78.9±20.3 and 71.2±30.5 vs. 51.9±19.5 and 51.3±21.1, respectively). In experiment 2, the IVF and parhenogenetic embryos at early (1–3 days) or late (4–7 days) stages were cultured in the NCSU-23 medium supplemented with 50 ng/ml AREG and the rate of blastocyst formation and total cell numbers of blastocyst was determined on Day 7. The rates of blastocyst formation did not differ between two groups compared to control group which was cultured in the medium without AREG. However, the total cell numbers of blastocyst at late stage group was significantly higher (p < 0.05) than those of control and in IVF embryos (75.8±27.3 vs. 58.0±23.8, respectively). Besides, the total cell numbers of blastocyst at early stage group and late stage group was significantly higher (p < 0.05) than control group in parthogenetic embryos (77.0±19.0 and 81.2±19.3 vs. 64.4±20.5, respectively). These results suggested that supplementation of AREG in the culture medium, mainly at late preimplantation stage of embryo, improves the subsequent blastocyst formation that exhibit more quality by increasing cell proliferation in the IVF porcine and parthenogenetic embryos. (poster)