B. The immunofluorescence images show the pERK1/2 (red) dynamics in immature (GV, n=5), mature (MII, n=10), and fertilized oocytes from unidentified control patients (n=6), as well as in mature oocytes from patient 1 carrying homozygous MOSAsn95Lys variants. pERK1/2 activation was inhibited after U0126 treatment (n=6). FITC-α-tubulin (Green) and DAPI (blue) were used for co-staining. Scale bar=10 µm. 