State-of-the-art production, conservation and transfer of in-vitro-produced embryos in small ruminants

Abstract

Today, although not efficient enough to replace multiple ovulation and embryo transfer, in vitro embryo production for small ruminants is a platform for new reproductive technologies, such as embryo sexing, transgenesis and cloning. The in vitro embryo-production system developed for sheep and goats is more efficient now than 15 years ago, but could still be improved. Laparoscopic collection of oocytes in live animals treated with gonadotrophin indicates a promising future for the application of this technology to genetic improvement programmes. Oocyte maturation in defined medium with epidermal growth factor and cysteamine appears as efficient as oocyte maturation in follicular fluid-supplemented medium and allows future study of the effect of other factors involved in the cytoplasmic maturation of oocytes from these species. Further efforts have to be made to standardise the semen-capacitating process and to improve the quality and freezability of in-vitro-produced (IVP) embryos. The optimisation of IVP procedures for deer species has required the study of the seasonal variation of oocyte competence and the development of a specific methodology to allow the culture of embryos up to the blastocyst stage.

Laparoscopic ovum pick-up followed by in vitro embryo production for the reproductive rescue of aged goats of high genetic value

“…In addition, the results are comparable to or better than those reported by other groups working with in vitro-produced goat embryos (Cognie et al 2003(Cognie et al , 2004Katska-Ksiazkiewicz et al 2004).…”

“…As suggested in the literature (Cognie et al 2004;Katska-Ksiazkiewicz et al 2004), frozen semen samples are ready to fertilise in vitro after Percoll motility enrichment, without the need for capacitating agents (e.g. heparin).…”

“…Laparoscopic ovum pick-up (LOPU) followed by in vitro embryo production (IVEP) has been proposed as an efficient method for the exponential propagation of female sheep and goats of high genetic value (Baldassarre et al 1996(Baldassarre et al , 2002Tervit 1996;Cognie et al 2004). Several advantages compared with the standard multiple ovulation and embryo transfer (MOET) method have been highlighted by several authors.…”

Embryo development, fetal growth and postnatal phenotype of eGFP lambs generated by lentiviral transgenesis

“…Mechanism by which these alterations occurs is not clear enough, but could be due to disturbance of cell lineage differentiation in the blastocyst during in vitro culture of the embryo and/or alterations during in vitro maturation of the oocyte (Lonergan and Fair 2008). However, current conditions for oocyte maturation and embryo culture have been modified, evolved and improved during the last years and probably this limitation has been overcome (Cognie et al 2004). In the current study and working under our conditions, this problem was not evident in none of the 15 lambs produced in vitro (IVF and TG groups) in comparison with 16 lambs produced by intrauterine insemination.…”

Differences in amniotic amino acid concentrations between pregnancies obtained with transfer of vitrified thawed in vitro–produced embryos and with natural mating in sheep

“…To control and improve animal reproduction, assisted reproductive technologies (ART) have been developed, such as artificial insemination, multiple ovulation, embryo transfer, and in vitro production of embryos (IVP) [1,2]. The latter technique involves four major steps: oocyte collection (either from a live animal via ovum pick up or from ovaries recovered at slaughter), oocyte in vitro maturation, fertilization, and development of the embryo up to the blastocyst stage.…”