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Pipetting induced shear stress
• In-vivo embryos do not experience acute shear stress; such stress is induced by high-sustained velocity through too vigorous handling
• Even though human embryo studies do not exist, studies on mouse embryos show that embryos sense shear stress and thus SS may be correlated with the kinetics and the enzymatic mechanisms underlying induction of embryonic lethality (Xie Y 2006,2007)
• Despite the fact that some new technologies like time-lapse might be adventagous by reducing the no. of handling events, some others like embryo biopsy for PGT might increase such manuplation
• Since embryo handling is an inavitable procedure of human ART, it should be performed with care and kept to a minimum.
SS is a potent inducer of embryonic lethality and that ZP protects the embryo from it.MAPK8/9 phosphorylation is induced by SS Preceeding TUNEL induction that is associated with embryo death.TE cells of the blastocyst sense SS and SS may lead directly to apoptosis
SS may cause rapid transient changes in hundreds of proteins and mRNA
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