Arias María Elena, Vargas Tamara, Gallardo Victor, Aguila Luis, Felmer Ricardo
Laboratory of Reproduction, Centre of Reproductive Biotechnology (CEBIOR-BIOREN), Universidad de La Frontera, Temuco 4811322, Chile.
Department of Agricultural Production, Faculty of Agriculture and Environmental Sciences, Universidad de La Frontera, Temuco 4811322, Chile.
Animals (Basel). 2022 Nov 7;12(21):3057. doi: 10.3390/ani12213057.
Supplementation of the culture media for in vitro production (IVP) of bovine embryos with fetal bovine serum (FBS) is associated with inconsistent outcomes. The present study sought to replace FBS and BSA by insulin-like growth factor 1 (IGF1), fibroblast growth factor 2 (FGF2) and epidermal growth factor (EGF). In Experiment 1, absence of FBS from maturation medium (MM) did not affect the rate of in vitro maturation, as assessed by the extrusion of the first polar body. However, when gonadotropins and FBS were removed from the MM, the maturation rate was significantly reduced even in the presence of growth factors. Therefore, gonadotropin-supplemented MM medium was established as the base medium for the defined maturation condition. In Experiment 2, the addition of growth factors to gonadotropin-supplemented MM medium supported similar maturation (~90%) compared to the undefined condition (FBS-carrying). In Experiment 3, the addition of growth factors to embryo culture medium showed similar in vitro competence compared to the undefined (FBS) control. In Experiment 4, completely defined conditions (absence of FBS and BSA during in vitro maturation and embryo culture) were tested. A higher cleavage was observed with FGF2 (86%) compared to EGF (77%) and the FBS control (77%), but similar blastocyst rates were observed for FGF2 (24%), EGF (19%) and the FBS control (25%). Embryo quality was similar among groups. Finally, post-thawing survival was higher for FGF2 (94%) compared to the FBS control (77%). Thus, we report a simple defined IVP system for bovine species that generates developmental outcomes and embryos of similar quality than those produced under conditions containing FBS.
在体外生产（IVP）牛胚胎的培养基中添加胎牛血清（FBS）会导致结果不一致。本研究试图用胰岛素样生长因子1（IGF1）、成纤维细胞生长因子2（FGF2）和表皮生长因子（EGF）替代FBS和牛血清白蛋白（BSA）。在实验1中，成熟培养基（MM）中不含FBS并不影响体外成熟率，这通过第一极体的排出进行评估。然而，当从MM中去除促性腺激素和FBS时，即使存在生长因子，成熟率也会显著降低。因此，添加了促性腺激素的MM培养基被确立为确定的成熟条件的基础培养基。在实验2中，与未确定条件（含FBS）相比，向添加了促性腺激素的MM培养基中添加生长因子可支持相似的成熟率（约90%）。在实验3中，与未确定（FBS）对照相比，向胚胎培养基中添加生长因子显示出相似的体外发育能力。在实验4中，测试了完全确定的条件（体外成熟和胚胎培养期间不存在FBS和BSA）。与EGF（77%）和FBS对照（77%）相比，FGF2组观察到更高的卵裂率（86%），但FGF2组（24%）、EGF组（19%）和FBS对照组（25%）的囊胚率相似。各组间胚胎质量相似。最后，与FBS对照（77%）相比，FGF2组解冻后的存活率更高（94%）。因此，我们报告了一种简单的、确定的牛体外生产系统，该系统产生的发育结果和胚胎质量与在含FBS条件下产生的相似。
