title: Human oocyte developmental potential is predicted by mechanical properties within hours after fertilization.
abstract: The causes of embryonic arrest during pre-implantation development are poorly understood. Attempts to correlate patterns of oocyte gene expression with successful embryo development have been hampered by the lack of reliable and nondestructive predictors of viability at such an early stage. Here we report that zygote viscoelastic properties can predict blastocyst formation in humans and mice within hours after fertilization, with >90% precision, 95% specificity and 75% sensitivity. We demonstrate that there are significant differences between the transcriptomes of viable and non-viable zygotes, especially in expression of genes important for oocyte maturation. In addition, we show that low-quality oocytes may undergo insufficient cortical granule release and zona-hardening, causing altered mechanics after fertilization. Our results suggest that embryo potential is largely determined by the quality and maturation of the oocyte before fertilization, and can be predicted through a minimally invasive mechanical measurement at the zygote stage.
authors.affiliation: Department of Bioengineering, Stanford University School of Engineering, Stanford, California 94305, USA.
authors.forename: Livia Z
authors.initials: LZ
authors.lastname: Yanez
authors.affiliation: Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California 94305, USA.|Department of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, California 94305, USA.
authors.forename: Jinnuo
authors.initials: J
authors.lastname: Han
authors.affiliation: Department of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, California 94305, USA.
authors.forename: Barry B
authors.initials: BB
authors.lastname: Behr
authors.affiliation: Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California 94305, USA.|Department of Cell Biology, Neuroscience and Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, USA.
authors.forename: Renee A Reijo
authors.initials: RAR
authors.lastname: Pera
authors.affiliation: Department of Bioengineering, Stanford University School of Engineering, Stanford, California 94305, USA.
authors.forename: David B
authors.initials: DB
authors.lastname: Camarillo
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D001755:Blastocyst / Q000502:physiology*; D004548:Elasticity; D004622:Embryo, Mammalian / Q000196:embryology*; D047108:Embryonic Development; D005307:Fertilization in Vitro; D018507:Gene Expression Regulation, Developmental; D063990:Gene Ontology; D053263:Gene Regulatory Networks; D006801:Humans; D051379:Mice; D018613:Microscopy, Confocal; D009865:Oocytes / Q000502:physiology*; D059467:Transcriptome; D014783:Viscosity; D015053:Zygote / Q000502:physiology*