Developmental competence in vivo and in vitro of in vitro-matured equine oocytes fertilized by intracytoplasmic sperm injection with fresh or frozen-thawed spermatozoa

In vitro development of equine nuclear transfer embryos: effects of oocyte maturation media and amino acid composition during embryo culture

“…The ICSI procedure was conducted as previously described (Choi et al, 2002c) the outside diameter of the sperm injection pipette was 7-8 µm. A 120-140 µm (outside diameter) pipette was used to hold the oocytes.…”

Pre-selection by double layer density gradient centrifugation improves the fertilising capacity of frozen–thawed, capacitated stallion sperm

“…Likewise, Landim-Alvarenga et al (2001) obtained similar penetration rates (13.3%) when treating stallion sperm samples with dilauroylphosphatidylcholine (PC-12) or the calcium ionophore A23187. Actually, other authors have tried to capacitate stallion spermatozoa using other different compounds and protocols (Campos-Chillòn et al, 2007;Choi et al, 2002;Klewitz et al, 2010;McPartlin et al, 2006McPartlin et al, , 2009Spizziri et al, 2010;Wilhelm et al, 1996) however the results are poor and not repeatable (reviewed by Hinrichs, 2013). Higher than our results and of great interest were the results obtained by Taberner et al (2010) using the 0.1 M ionomycin treatment to capacitate frozen-thawed donkey spermatozoa (85.4%).…”

“…A major difficulty encountered with IVF in equine species-in part responsible for its almost complete abandonment -is sperm capacitation. Certainly, during the 1990s the lack of a successful equine IVF protocol led to embryos being produced via other technologies, such as the transfer of in vitro-matured oocytes into the oviduct of recipient mares for fertilisation in vivo (Hinrichs, 1998), and more recently the fertilisation of oocytes via intracytoplasmic sperm injection (Choi et al, 2002;Dell'Aquila et al, 1996;Hinrichs, 2005Hinrichs, , 2010Hinrichs, , 2013Hinrichs et al, 2007;Rosati et al, 2002). The failure of equine IVF appears to be related to the incapacity of sperm cells to penetrate the zona pellucida in vitro; breaching the zona pellucida by partial dissection or dissolution with acidic solution can result in high rates of fertilisation, but can also lead to polyspermy (Choi et al, 1994;Li et al, 1995).…”

The Role of Oviductal Cells in Activating Stallion Spermatozoa

“…Besides the fact that ICSI requires expensive equipment and highly trained technicians, the oocyte may be damaged which presumably explains the low average blastocyst development rates. Only a few labs worldwide have been able to achieve satisfactory ICSI results (blastocyst rates of 15-35%) and subsequently be able to justify implementing this technique in a clinical setting to produce foals from sub-fertile horses [3,6]. If a repeatable conventional IVF system could be established, a cheaper and more practical system would be available.…”

“…Techniques like artificial insemination [1] and embryo transfer [2] are nowadays routine, while the in vitro production of equine embryos is gradually gaining popularity as a treatment for infertility and because it has a number of practical advantages. However, in vitro embryo production (IVEP) M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 3 3 can currently only be applied commercially using intracytoplasmic sperm injection (ICSI) [3][4][5][6].…”