Comparison of the interferon‐tau expression from primary trophectoderm outgrowths derived from IVP, NT, and parthenogenote bovine blastocysts

Abstract

The expression of interferon-tau (IFN-tau) is essential for bovine embryo survival in the uterus. An evaluation of IFN-tau production from somatic cell nuclear transfer (NT)-embryo-derived primary trophectoderm cultures in comparison to trophectoderm cultured from parthenogenote (P) and in vitro matured, fertilized, and cultured (IVP) bovine embryos was performed. In Experiment 1, the success/failure ratio for primary trophectoderm colony formation was similar for IVP and NT blastocysts [IVP = 155/29 (84%); NT 104/25 (81%)], but was decreased (P = .05) for P blastocysts [54/43 (56%)]. Most trophectoderm colonies reached diameters of at least 1 cm within 3-4 weeks, and at this time, 72 hr conditioned cell culture medium was measured for IFN-tau concentration by antiviral activity assay. The amount of IFN-tau produced by IVP-outgrowths [4311 IU/mL (n = 155)] was greater (P < .05) than that from NT- [626 IU/mL (n = 104)] and P - [1595 IU/mL (n = 54)] derived trophectoderm. Differential expression of IFN-tau was confirmed by immunoblotting. In Experiment 2, colony formation was again similar for IVP and NT blastocysts [IVP = 70/5 (93%); NT 67/1 (99%)] and less (P < .05) for P blastocysts [65/27 (70%)]. Analysis of trophectoderm colony size after 23 days in culture showed a similar relationship with P-derived colonies being significantly smaller in comparison to IVP and NT colonies. A differential expression of IFN-tau was also observed again, but this time as measured over time in culture. Maximal IFN-tau production was found at day-14 of primary culture and diminished to a minimum by the 23rd day.

Embryonic Development and Implantation Related Gene Expression of Oocyte Reconstructed with Bovine Trophoblast Cells

“…Hatched blastocysts were attached to a mouse feeder layer, and BT cells with a cuboidal morphology [12] were maintained for further culture (Fig. 1).…”

“…Primary cultures of bovine trophoblasts were done as described previously [12]. Briefly, hatched blastocysts produced by IVF were plated into 4-well tissue culture dishes on day 10 to 11 of their development (Nunc, Thermo Scientific, Roskilde, Denmark).…”

“…Some reports have demonstrated trophoblast isolation and its function in vitro in cattle [10][11][12]. In mice, living pups were born by nuclear transfer of trophectoderm cells from the expanded blastocysts into enucleated oocytes [13] as a trial to show the similarity in totipotency of both ICM and trophoblast cells from a single blastocyst.…”

Proteomic analysis of the major cellular proteins of bovine trophectoderm cell lines derived from IVP, parthenogenetic and nuclear transfer embryos: Reduced expression of annexins I and II in nuclear transfer-derived cell lines

“…In vitro-produced (IVP) blastocysts of cattle derived from either in vitro maturation, fertilization, and culture (IVF), or somatic cell nuclear transfer (NT), or parthenogenetic activation (P) were produced from oocytes obtained from slaughter house ovaries as previously described (Powell et al, 2004;Talbot et al, 2007aTalbot et al, , 2008. Blastocysts of good morphological quality were used to establish trophectoderm cell lines.…”

“…The trophectoderm is the embryonic tissue that mediates placental connections with the uterine epithelium, and it was recently reported that DNA methylation anomalies were specifically localized to this tissue in NT cattle embryos (Kang et al, 2002). Also, changes in the expression of key secretory proteins of trophectoderm have been found in NT embryos of cattle (Wrenzycki et al, 2001;Talbot et al, 2008). The analysis of trophectoderm cells might therefore be useful in determining epigenetic deficiencies that lead to placental dysfunction in NT cattle.…”