Emerging roles and mechanisms of ERK pathway mechanosensing.

The coupling between mechanical forces and modulation of cell signalling pathways is essential for tissue plasticity and their adaptation to changing environments. Whilst the number of physiological and pathological relevant roles of mechanotransduction has been rapidly expanding over the last decade, studies have been mostly focussing on a limited number of mechanosensitive pathways, which include for instance Hippo/YAP/TAZ pathway, Wnt/β-catenin or the stretch-activated channel Piezo. However, the recent development and spreading of new live sensors has provided new insights into the contribution of ERK pathway in mechanosensing in various systems, which emerges now as a fast and modular mechanosensitive pathway.

Filopodia-like protrusions of adjacent somatic cells shape the developmental potential of oocytes.

The oocyte must grow and mature before fertilization, thanks to a close dialogue with the somatic cells that surround it. Part of this communication is through filopodia-like protrusions, called transzonal projections (TZPs), sent by the somatic cells to the oocyte membrane. To investigate the contribution of TZPs to oocyte quality, we impaired their structure by generating a full knockout mouse of the TZP structural component myosin-X (MYO10).

Myosin-X is dispensable for spindle morphogenesis and positioning in the mouse oocyte.

Off-center spindle positioning in mammalian oocytes enables asymmetric divisions in size, which are important for subsequent embryogenesis. The migration of the meiosis I spindle from the oocyte center to its cortex is mediated by F-actin. Specifically, an F-actin cage surrounds the microtubule spindle and applies forces to it.

Artificially decreasing cortical tension generates aneuploidy in mouse oocytes.

Human and mouse oocytes' developmental potential can be predicted by their mechanical properties. Their development into blastocysts requires a specific stiffness window. In this study, we combine live-cell and computational imaging, laser ablation, and biophysical measurements to investigate how deregulation of cortex tension in the oocyte contributes to early developmental failure.