Global cattle genetic market is experiencing a change of strategy, large genetic companies, traditionally recognized in the artificial insemination field, have also begun to operate in the embryo market. Consequently, the demand for in vitro produced (IVP) embryos has grown. However, the overall efficiency of the biotechnology process remains low. Additionally, the lack of homogeneity of post-cryopreservation survival results of IVP embryos still impairing a massive dissemination of this biotechnology in the field. A great challenge for in vitro production labs is to increase the amount of embryos produced with exceptional quality after each round of in vitro fertilization. Herein, we discuss the molecular and cellular features associated with the competence and cryosurvival of IVP embryos. First, morphofunctional, cellular and molecular competence of the embryos were addressed and a relationship between embryo developmental ability and quality were established with cryosurvival and pregnancy success. Additionally, determinant factors of embryo competence and cryosurvival were discussed including the following effects: genotype, oocyte quality and follicular microenvironment, in vitro production conditions, and lipids and other determining molecules. Finally, embryo cryopreservation aspects were addressed and an embryofocused approach to improve cryosurvival was presented.

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Although well-established and adopted by commercial laboratories, the in vitro embryo production system still requires refinements to achieve its highest efficiency. Early embryonic development is a dynamic event, demanding suitable conditions to provide a high number of embryos with quality and competence. The first step to obtaining an optimized in vitro environment is to know the embryonic metabolism and energy request throughout the different stages of development. Oxygen plays a crucial role in several key biological processes necessary to sustain and complete embryonic development. Nonetheless, there is still controversy regarding the optimal in vitro atmospheric concentrations during culture. Herein, we discuss the impact of oxygen tension on the viability of in vitro-produced embryos during early development. The importance of oxygen tension is addressed as its roles regarding essential embryonic traits, including embryo production rates, embryonic cell viability, gene expression profile, epigenetic regulation, and post-cryopreservation survival. Finally, we highlight the damage caused by in vitro unbalanced oxygen tensions and strategies to mitigate the harmful effects.

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The cryosurvival of embryos is a complex process involving dynamic and integrated morphological, functional, and molecular changes. Here, we evaluated the transcriptional profiling of bovine embryos possessing high and low cryotolerance (HC and LC, respectively) by assessing the resumption of development. Embryos were produced in vitro (N = 1137) and cryopreserved (N = 894). Blastocysts samples possessed pronounced group individualization at RNA sequencing. A total of 114 genes were differentially expressed, and 27 and 84 genes were upregulated in HC and LC, respectively. Among the over-represented biological functions, cellular growth and proliferation, cell death and survival, and organismal survival were predicted to be activated, while cellular movement and cell-to-cell signaling were predicted to be inhibited in HC embryos. Enriched canonical pathways and upstream regulators related to cellular proliferation and survival (HC), inflammatory processes, and cell death (LC) were predicted to represent two embryonic molecular profiles present during the resumption of development after cryopreservation. The marked contrast in transcriptional profiles between HC and LC strongly suggests the influence of embryonic competence after cryopreservation on its respective transcriptome and indicated that HC and LC presented two different molecular strategies to overcome cryopreservation-related stress and resume postcryopreservation development.