Getting Attached
The blastocyst is a structure that develops around the early embryo before it implants into the wall of the womb. It's essential for implantation and is formed through a series of cell divisions. This involves cell machinery that controls contractility, including proteins such as actin and myosin. Researchers now investigate subunits of myosin called non-muscle myosin II heavy chains (NHMC). Using mouse embryos they created mutants lacking NMHC II-A or NMHC II-B or both. They find NMHC II-A caused major defects in cell division, reduced maturation of cells and other morphological defects in the embryo. NHMC II-B mutants had less severe defects. Double mutants had the most severe defects with cell division failing completely in most cases. However, all mutants were still able to create fluid-filled vacuoles, which is part of the normal process of readying the blastocyst for implantation. This reveals that some events involved in pre-implantation are unaffected by defects in contractility but also that NMHC II-A is the major player in regulating contractility in preparation for implantation.
Written by Lux Fatimathas
Image from work by Markus Frederik Schliffka and Anna Francesca Tortorelli, and colleagues
Genetics and developmental biology unit, Institut Curie, Paris, France
Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
Published in eLife, April 2021
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