Yunan Ye - A circuitous nuclear centring process risks embryonic divisions becoming asymmetric in early mouse embryos

Overview: Morpho-kinetic features of early cleavage-stage embryos are known to be important predictors of embryo quality and IVF treatment outcome. A prominent feature of good-quality embryos is the ability to produce equal-sized daughter-cells with each division, termed symmetrical division.  Conversely, asymmetrical divisions leading to variable blastomere sizes is a red flag for poor developmental potential. Notably, very little is known about the origins of division asymmetry in embryos. Using high-resolution 4D live imaging to track chromosomes during the first cleavage division in mouse embryos, we uncovered a circuitous nuclear centring process that risks embryonic divisions becoming asymmetric in early mouse embryos.