RT Journal Article SR Electronic T1 Filopodia-like protrusions of adjacent somatic cells shape the developmental potential of oocytes JF Life Science Alliance JO Life Sci. Alliance FD Life Science Alliance LLC SP e202301963 DO 10.26508/lsa.202301963 VO 6 IS 6 A1 Flora Crozet A1 Gaëlle Letort A1 Rose Bulteau A1 Christelle Da Silva A1 Adrien Eichmuller A1 Anna Francesca Tortorelli A1 Joséphine Blévinal A1 Morgane Belle A1 Julien Dumont A1 Tristan Piolot A1 Aurélien Dauphin A1 Fanny Coulpier A1 Alain Chédotal A1 Jean-Léon Maître A1 Marie-Hélène Verlhac A1 Hugh J Clarke A1 Marie-Emilie Terret YR 2023 UL https://www.life-science-alliance.org/content/6/6/e202301963.abstract AB 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). Using spinning disk and super-resolution microscopy combined with a machine-learning approach to phenotype oocyte morphology, we show that the lack of Myo10 decreases TZP density during oocyte growth. Reduction in TZPs does not prevent oocyte growth but impairs oocyte-matrix integrity. Importantly, we reveal by transcriptomic analysis that gene expression is altered in TZP-deprived oocytes and that oocyte maturation and subsequent early embryonic development are partially affected, effectively reducing mouse fertility. We propose that TZPs play a role in the structural integrity of the germline–somatic complex, which is essential for regulating gene expression in the oocyte and thus its developmental potential.