Effects of Sperm Pretreatments and In vitro Culture Systems on Development of In vitro Fertilized Embryos Derived from Prepubertal Boer Goat Oocytes in China

Lihua Lv,George W Smith,Wenzhong Liu,Fuzhong Li,Wenbin Yue,Youshe Ren,Kyung-Bon Lee

doi:10.5713/ajas.2009.90060

Abstract

Use of oocytes from prepubertal animals for in vitro embryo production holds potential application for reducing generation intervals and increasing genetic progress through embryo transfer. The objective of these studies was to compare the effect of three sperm pretreatments (prior to in vitro fertilization) and seven embryo culture protocols on fertilization rate and (or) subsequent development of in vitro fertilized embryos derived from oocytes harvested from ovaries of 1-6 month old prepubertal Boer goats in China. Cleavage rates were highest for embryos fertilized with heparin-treated versus calcium ionophore- or caffeine-treated sperm. Similar rates of blastocyst development were observed using heparin- and ionophore-treated sperm, which were higher than obtained with caffeine-treated sperm. No differences in cleavage or blastocyst rates were observed following embryo culture in basal medias (synthetic oviductal fluid (SOF), Charles Rosenkrans 1 (CR1) or tissue culture medium-199 (TCM-199)) containing 10% fetal bovine serum (FBS). Cumulus or oviductal cell co-culture did not enhance cleavage or blastocyst rates relative to culture in SOF+10% FBS. Replacement of FBS in SOF medium with 0.3% BSA increased cleavage rates, but did not increase rates of blastocyst development. Sequential culture in SOF+0.3% BSA followed by SOF+10% FBS increased blastocyst yield versus continuous culture in SOF+10% FBS and tended to increase blastocyst yield versus continuous culture in SOF+0.3% BSA. These results demonstrate a pronounced effects of sperm pretreatments and in vitro embryo culture systems on rates of blastocyst development and provide a potential protocol (sperm pretreatment with heparin and sequential embryo culture in SOF+0.3% BSA followed by SOF+10% FBS) for generation of the significant numbers of in vitro produced blastocysts from oocytes of prepubertal Boer goats necessary for application of embryo transfer in rural regions of China for distribution of Boer goat genetics.

Highlights

Goats are a prominent food source in many developing countries, including China
Results support use of heparin for sperm pretreatment prior to in vitro fertilization (IVF) resulting in higher cleavage and blastocyst rates for in vitro produced embryos derived from prepubertal goat oocytes and indicate that caffeine pretreatment of goat spermatozoa is detrimental to fertilization and subsequent development of IVF embryos
Application of in vitro embryo production using oocytes harvested from prepubertal animals coupled with embryo transfer holds potential for propagation of Boer goat genetics in rural regions of China to enhance rates of genetic progress

Summary

Introduction

Goats are a prominent food source in many developing countries, including China. Goat inventories in China are estimated at over 1×109 animals (Yonghong, 2002). The vast majority of such animals represent indigenous breeds. Boer goats were introduced into China in 1995 and offer. Previous studies have focused on the use of MOET (multiple ovulation embryo transfer) technology (Mishra et al, 2003; Mishra et al, 2004; Chang et al, 2006) as a means of propagation of Boer goat genetics. Cloning of high genetic merit goats by somatic cell nuclear transfer represents another potential approach (Park et al, 2007). Our long-term goal is to develop effective procedures for in vitro production and subsequent transfer of embryos derived from oocytes of prepubertal Boer goats

Methods

Results

Conclusion