Up date of in vitro production of porcine embryos

Abstract

There have been intensive attempts to establish reliable in vitro maturation (IVM) and fertilization (IVF) methods in pigs. Although a great deal of progress has been made, current IVM-IVF systems still suffer from a low rate and poor quality of in vitro produced embryos . In this review, we will review the recent studies about IVM-IVF of porcine oocytes and the in vitro culture (IVC) system, especially modified in vitro production (IVP) system that produces high quality of porcine blastocysts. We then try to suggest practical ways to solve the problems mentioned above in the pigs.

Pre-fertilization zona pellucida hardening by different cross-linkers affects IVF in pigs and cattle and improves embryo production in pigs

“…Although the in vitro maturation and fertilization proceed with standard regularity, the proportion of embryos that reach the blastocyst stage is rarely over 40% in cattle (Lonergan & Fair 2008), while in pigs, proportions rarely reach 20% (Nagai et al 2006). The main causes for these inefficiencies are very distinct differences between cattle and pig, where polyspermic fertilization is a major problem in pigs.…”

Obtaining farm animal embryos <i>in vitro</i>

“…Immature oocytes are surrounded by several tightly packed layers of granulosa cells called the corona radiata, with which they form the cumulus-oocyte complex (COC), and a cluster of cells forming the cumulus oophorus (Abeydeera, 2002;Cognie et al, 2003;Hoshi, 2003;Nagai et al, 2006;Lonergan, 2007;Lonergan and Fair, 2008;Gil et al, 2010;Paramio, 2010;Dang-Nguyen et al, 2011). In mares, oocytes can be surrounded by both tightly packed and dispersed layers of the corona radiata, but both types of oocytes are competed for maturation (Squires et al, 2003;Betteridge, 2006;Hinrichs, 2010Hinrichs, , 2010a.…”

“…This encompasses nuclear and cytoplasmic modifications and their mutual interactions, changes in embryo metabolism, embryonic genome activation, modifications of gene expression, formation of the morula and compaction of blastomeres, formation of the blastocyst with a characteristic structure named the blastocyst cavity that arises as a result of cavitation, and formation of additional structures such as the capsule in the horse embryos (Abeydeera, 2002;Cognie et al, 2003;Hoshi, 2003;Nagai et al, 2006;Lonergan, 2007;Lonergan and Fair, 2008;Gil et al, 2010;Paramio, 2010;Dang-Nguyen et al, 2011). The capsule is a structure located between trophoblast and zona pellucida, which is generated by the embryo.…”

“…The granulosa cells of the corona radiata play an important role in the maturation of the oocyte, being responsible for contact of the oocyte with the environment and, therefore, mediating the hormonal and metabolic regulation of this process (Abeydeera, 2002;Cognie et al, 2003;Hoshi, 2003;Nagai et al, 2006;Lonergan, 2007;Lonergan and Fair, 2008;Gil et al, 2010;Paramio, 2010;Dang-Nguyen et al, 2011).…”

“…All of these requirements are characteristic of the respective farm animal species and have been described in detail in the literature: cattle (Hoshi, 2003;Lonergan, 2007;Lonergan and Fair, 2008), pigs (Abeydeera, 2002;Nagai et al, 2006;Lonergan and Fair, 2008;Gil et al, 2010;Dang-Nguyen et al, 2011), sheep and goats (Cognie et al, 2003;Paramio, 2010), and horses (Squires at el., 2003;Betteridge, 2006Betteridge, , 2007Hinrichs, 2010).…”