Effects of Oviductal Fluid, Culture Media and Zona Pellucida Removal on the Development of Porcine Embryos by Nuclear Transfer

Y H Zhang,Y J Yi,E S Song,J W Lee,E S Kim,C S Park,S H Lee,P Q Cong

doi:10.5713/ajas.2009.80693

Abstract

The aim of this study was to compare the effects of oviductal fluid, porcine zygote medium (PZM)-3, PZM-4 and PZM-5, and modified PZM-5 culture media, and determine the effects of zona pellucida (ZP) removal on the development of nuclear transfer (NT) embryos. There were no significant differences in the rates of fusion and cleavage among the five different oviductal fluid concentrations. However, the rates of blastocyst formation and the cell numbers per blastocyst were high in the embryos at the 14 and 28 μg/ml concentrations of oviductal fluid compared to the 0, 56 and 100 μg/ml concentrations. The rates of cleavage and blastocyst formation, and the cell numbers per blastocyst were higher in the PZM-3, PZM-5 and modified PZM-5 media than in the PZM-4 medium. However, there were no significant differences in the fusion rates of oocytes among the four culture media. The cell numbers per blastocyst in the embryos without ZP were significantly greater than those with ZP. However, there were no significant differences in the rates of fusion, cleavage and blastocyst formation between the embryos with and without ZP. In conclusion, we improved blastocyst development and the quality of NT embryos by replacing PVA with 3 mg/ml of BSA in PZM-5 medium and supplementing the PZM-5 medium with 14 μg/ml oviductal fluid. The NT embryos produced by the zona-free NT method had a high rate of blastocyst formation in the modified PZM-5 medium. (Key Words : Oviductal Fluid, Nuclear Transfer, Culture Media, Zona Pellucida, Porcine)

Highlights

Important functions of the oviduct during reproduction include the provision of an optimal environment for gametes and zygotes and nutrition of the early embryos
A similar medium, called porcine zygote medium (PZM)-3 (Zhang et al, 2009), was used for embryo culture of both in vitro fertilization (IVF) and nuclear transfer (NT) embryos and in the latter case it was found to be more efficient than NCSU-23 (Im et al, 2004) the blastocysts obtained were not transferred into recipients
It has been shown that an increased number of embryos will develop to blastocyst in vitro when incubated in culture medium previously conditioned by oviductal cells (Rexroad and Powell, 1988) or in medium supplemented with oviductal fluid (Archibong et al, 1989)

Summary

Introduction

Important functions of the oviduct during reproduction include the provision of an optimal environment for gametes and zygotes and nutrition of the early embryos These functions are ensured by the secretion of an oviductal fluid which is known to contain organ-specific glycoproteins. Oviductal fluid, secreted by the oviduct epithelium, provides a perfect environment for reproductive processes (such as oocyte maturation, capacitation of spermatozoa, and fertilization) and is essential for the nutrition of the early embryo (Leese, 1988). A similar medium, called PZM-3 (Zhang et al, 2009), was used for embryo culture of both IVF and NT embryos and in the latter case it was found to be more efficient than NCSU-23 (Im et al, 2004) the blastocysts obtained were not transferred into recipients

Objectives

Results

Conclusion