...Jenna Treissman; Victor Yuan; Jennet Baltayeva; Hoa T. Le; Barbara Castellana; Wendy P. Robinson; Alexander G. Beristain ABSTRACT Early placental development and the establishment of the invasive trophoblast lineage take place within a low oxygen environment. However, conflicting and inconsistent...

..., suggesting a role in placental development. Here, we evaluate that role. A knock-in reporter for the mouse miR-290 cluster is expressed throughout the embryo until gastrulation, when it becomes specifically expressed in extraembryonic tissues and the germline. In the placenta, expression is limited...

... not caused by failure in cell migration, but rather by abnormal placentation. The β 1D knock-in embryos that survived midgestation developed until birth, but exhibited severely reduced skeletal muscle mass. Quantification of myotube numbers showed that substitution of β 1A with β 1D impairs primary...