02656naa a2200337 a 450000100080000000500110000800800410001902400560006010000170011624501530013326000090028652016100029565000240190565000200192965000090194965000200195865000100197865300240198865300280201265300250204065300330206570000220209870000220212070000190214270000210216170000200218270000220220270000250222470000270224977300420227621241602025-01-10       2020    bl uuuu     u00u1 u    #d7 ahttps://doi.org/10.1016/j.cryobiol.2020.05.0092DOI1 aBRAIR, V. L.  aGene expression patterns of in vivo-derived sheep blastocysts is more affected by vitrification than slow freezing technique.h[electronic resource]  c2020  aTransfer of fresh sheep embryos frequently results in higher pregnancy rate compared to cryopreserved ones, possibly due to a failure in the communication between the cryopreserved embryo and the endometrium during pre-implantation and pregnancy establishment. Thus, this study assessed the effect of sheep embryo cryopres-ervation (slow freezing or vitrification) on embryo survival rate and expression of genes related to trophectoderm differentiation (CDX2), pluripotency maintenance (NANOG), cell proliferation (TGFB1), mitochondrial activity (NRF1) and apoptosis (BAX and BCL2). Superovulation (n ¼32 ewes) was performed and embryos were transcervically collected. One hundred good quality (Grade I and II) embryos were allocated into three groups: fresh embryos (CTL; n ¼15), slow freezing (SF; n ¼42) or vitrification (VT; n ¼43). After thawing/warming, three pools of five blastocysts per group were used for RT-qPCR; the remaining 55 embryos were cultured in vitro in SOFaa medium at 38.5 �C and 5% CO2 (SF: n ¼27 and VT: n ¼28). Survival rate of SF and VT were, respectively, 29.6% (8/27) and 14.2% (4/28) at 24 h; and 48.1% (13/27) and 32.1% (9/28) at 48 h (P &gt0.05). Only CDX2 was affected (up-regulated, P &lt0.05) in both groups compared to CTL. The BAX transcript was upregulated in VT, compared to SF group. The VT increased (P &lt0.05) the expression of all genes, except for NANOG and NRF1, when compared to the CTL. In conclusion, although in vitro survival was similar between techniques, VT led to increased changes in blastocyst gene expression compared to CTL and SF.  aEmbryo implantation  aEmbryo transfer  aEwes  aGene expression  aSheep  aApoptosis regulator  aEmbryo cryopreservation  aEmbryonic metabolism  aReproductive biotechnologies1 aMAIA, A. L. R. S.1 aCORREIA, L. F. L.1 aBARBOSA, N. O.1 aSANTOS, J. D. R.1 aBRANDÃO, F. Z.1 aFONSECA, J. F. da1 aBATISTA, R. I. T. P.1 aSOUZA-FABJAN, J. M. G.  tCryobiologygv. 95, p. 110-115, 2020.