In vitro bovine embryo production in a synthetic medium: Embryo development, cryosurvival, and establishment of pregnancy

Abstract

a b s t r a c tThe aim of this study was to develop an in vitro embryo culture medium without either fetal calf serum or BSA, using various growth factors and cytokines (GFs-CYKs; IGF-I, IGF-II, bFGF, LIF, GM-CSF, TGF-b1, and PDGF-BB), and other molecules with surfactant and embryotrophic properties, such as recombinant albumin (RA) and hyaluronan (HA). The first part of the study was dedicated to define the best combination of GFs-CYKs þ RA þ HA for optimal embryonic development. Next, we compared development rates and embryo quality (inner cell mass [ICM]-to-total cell number [TCN] ratio), and postthaw survival and hatching rates using this synthetic medium (T1) and a control medium: synthetic oviduct fluid þ BSA þ ITS (insulin, transferrin, and selenium). The blastocyst rates were significantly higher with T1 than those with the control at 7 and 8 days after fertilization. There was no significant difference in TCN or the ICM/TCN ratio between the two treatments. Survival and hatching rates 48 hours after thawing were similar for both treatments. Finally, nine embryo transfers were conducted using fresh and previously frozen Day-7 blastocysts to evaluate the in vivo viability of embryos produced in this synthetic medium; four gestations were obtained from six fresh embryos and one gestation from three frozen embryos. In conclusion, the fetal calf serum and BSA-free medium, supplemented with GFs-CYKs þ RA þ HA, improved embryo development and gave comparable ICM/TCN ratios and postthaw survival rates to the control with BSA. Fresh and frozen embryos produced in this medium are viable for embryo transfer. This fully synthetic method of embryo culture is a useful means of reducing the risk of disease transmission via embryo transfer.

46 Vitrification of Immature and Mature Bovine Oocytes

“…The embryo will be dividing rapidly at this time and by day seven the embryo will be ready for transfer (Moreno et. al, 2015).…”

“…To transfer an embryo a catheter containing the embryos is inserted into the vagina, through the cervix, and up into the uterus. Pregnancy occurs and is successful if an embryo sticks and is implanted in the lining of the uterus and grows (Moreno et. al, 2015).…”

The cytokine platelet factor 4 successfully replaces bovine serum albumin for the in vitro culture of porcine embryos

“…There have been several attempts to remove BSA from IVP systems to develop chemically defined media. The defined culture media are usually supplemented with polyvinyl alcohol (PVA), which provides a surfactant activity similar to albumin, and other molecules with embryotrophic properties such as growth factors or cytokines [7,8]. Based on the similarities between porcine embryonic cells and stem cells, Spate et al [9] recently successfully replaced the BSA in embryo culture medium with 5-(4chloro-phenyl)-3-phenyl-pent-2-enoic acid (PS48), an stimulant of the Warburg Effectlike metabolism [9] increasing outcomes.…”

C-kit signaling promotes human pre-implantation 3PN embryonic development and blastocyst formation

“…It has been acknowledged that multiple types of receptors expressed on the surface of the embryo play a key role in embryonic early development [3, 4], for example, growth factor receptors (GFRs), cytokine receptors (CRs) and hormone receptors (HRs) [5–7]. Furthermore, animal experiments showed that co-cultured with agonists or ligands of receptor tyrosine kinases (RTKs), including epidermal growth factor (EGF), colony stimulating factor (CSF), insulin like growth factor-1 (IGF-1) and so on, could remarkably promote embryo development and improve embryo quality [8–12]. Whereas, inhibition of RTKs function would weaken embryo growth ability resulting in arrest of development and even embryo degeneration [13–17].…”