biostudies-literatureNago MJapan Society for the Promotion of Sciencee12622https://www.ebi.ac.uk/biostudies/studies/S-EPMC11751902biostudies-literatureUnknown24(1)<h4>Purpose</h4>This study aimed to investigate the molecular mechanisms associated with chromosome segregation errors caused by intrinsic oxidative stress during in vitro oocyte maturation (IVM) using oocytes from <i>Sod1</i>-deficient (<i>Sod1</i>KO) mice.<h4>Methods</h4>Ovulated or in vitro matured cumulus-cells oocyte complexes (COCs) were collected from wild-type (WT) and <i>Sod1</i>KO mice and evaluated chromosome alignment, chromosome segregation, meiotic progression, and BUBR1 and REC8 protein expression levels.<h4>Results</h4>In 21% O₂ IVM, the <i>Sod1</i>KO had significantly higher frequencies of chromosome misalignment and segregation errors compared to the WT, and they also reached Germinal Vesicle Break Down (GVBD) and M I stages peak earlier and showed a shorter M Reproductive medicine and biology<i>Sod1</i> deficiency in mouse oocytes during in vitro maturation increases chromosome segregation errors with a reduced BUBR1 at kinetochore.PMC117519022458040521580342Ishii MOdajima KYanai MNago MSato YKimura Nfalse<i>Sod1</i> deficiency in mouse oocytes during in vitro maturation increases chromosome segregation errors with a reduced BUBR1 at kinetochore.<h4>Purpose</h4>This study aimed to investigate the molecular mechanisms associated with chromosome segregation errors caused by intrinsic oxidative stress during in vitro oocyte maturation (IVM) using oocytes from <i>Sod1</i>-deficient (<i>Sod1</i>KO) mice.<h4>Methods</h4>Ovulated or in vitro matured cumulus-cells oocyte complexes (COCs) were collected from wild-type (WT) and <i>Sod1</i>KO mice and evaluated chromosome alignment, chromosome segregation, meiotic progression, and BUBR1 and REC8 protein expression levels.<h4>Results</h4>In 21% O₂ IVM, the <i>Sod1</i>KO had significantly higher frequencies of chromosome misalignment and segregation errors compared to the WT, and they also reached Germinal Vesicle Break Down (GVBD) and M I stages peak earlier and showed a shorter M 2025-01-01T00:00:00Z2025 Jan-Dec2026-06-12T05:17:44.049Z2025-04-05T00:25:08.222ZS-EPMC117519023984548110.1002/rmb2.12622