Fig 1: Mutated Hnrnpr sperm induce disordered calcium oscillations in oocytes following ICSI.(A) Circular diagram illustrating genes associated with oocyte activation failure and their molecular mechanisms. Five sperm-borne and twenty-six oocyte-borne genes are listed as pathogenic contributors. (B) Fluorescence imaging of calcium signals in oocytes using the Fura-2 probe after ICSI with sperm from wild-type (WT) and knock-in (KI) male mice. The diffusible Fura-2 AM ester probe predominantly localizes to the cytoplasm after entering the cell. Scale bar = 10 μm. (C) Relative quantification of calcium signal intensity. Data are presented as mean ± s.d.; NS not significant. P values were determined using a two-sided Student’s t test. (D, E) Response of Ca²⁺ oscillations to changes in extracellular calcium concentrations (2 mM and 5 mM) across three independent experiments. (D) Representative traces. (E) Quantification of oscillation frequency under the indicated conditions. Data are shown as mean ± s.d.; NS not significant. P values determined using a two-sided Student’s t test. (F, G) Ca²⁺ oscillation imaging following histamine (MedChemExpress (Monmouth Junction, NJ, USA; Cat# HY-B1204)) stimulation (0 μM and 10 μM). (F) Representative traces. (G) Quantified oscillation frequencies, shown as mean ± s.d.; NS not significant. P values were calculated using a two-sided Student’s t test. (H–J) Ca²⁺ oscillation imaging in oocytes subjected to WT-ICSI, KI-ICSI, and KI-ICSI + AOA treatments. (H) Representative Fura-2 traces. (I) Quantification of oscillation frequency, shown as mean ± s.d.; NS not significant. P values were determined using a two-sided Student’s t test. (J) Representative traces obtained using Cal-520ER™ AM fluorescence imaging. Data in (B–J) represent results from three independent experiments (three biological replicates, n = 3). Source data are available online for this figure.