Title:Ami nem öl meg, az megerősít – új eljárás az asszisztált reprodukciós technikák hatásfokának növelésére
Summary Background: Several methods have been developed in the last decades, which require in vitro manipulation, culture, and fresh or cryopreserved storage of gametes and embryos. These techniques, like gamete and embryo cryopreservation, in vitro embryo production and culture, and somatic cell nuclear transfer necessitate meticulously adjusted conditions to avoid or minimize the harmful effects of uncontrolled stress. However, several studies in the last ten years indicate that purposefully applied stress have a positive effect on cells` quality, viability, and developmental competence. Objectives: The aim of this review is to summarize research results on the effects of stress preconditioning on gametes and embryos of several species, provided that this pretreatment is introduced before various processes of assisted reproduction. Materials and Methods: Review of the published literature. Results and Discussion: If gametes and embryos are subjected to a well-defined and properly applied stress, it may induce their general adaptation and increase tolerance to various in vitro procedures, like long-term storage, cryopreservation, culture, and manipulations. The term “well-defined and properly applied” is of capital importance; only this type of stress pretreatment may increase the general tolerance of the cells. Although cellular and subcellular mechanisms supposedly contributing to these processes require further research, the new principle, i.e., to improve the stress tolerance by a defined sublethal stress, instead of passively satisfying the cells’ physiological needs, may outline a completely new strategy in mammalian embryology, as well as cryopreservation of other cells and tissues. This procedure, besides its scientific value, may have significant practical consequences resulting in tangible economic benefits in many fields.