biostudies-literatureMomozawa KThe Japan Society for Reproductive Medicine365-371https://www.ebi.ac.uk/biostudies/studies/S-EPMC7542018biostudies-literatureUnknown19(4)<h4>Purpose</h4>In the present study, I evaluated the usefulness of Medium RD, with mixed RPMI1640 and Dulbecco's modified Eagle's medium (1:1, v/v), as a chemically defined medium for in vitro maturation (IVM) of bovine oocytes.<h4>Methods</h4>In vitro maturation was performed in 10 mmol/L HEPES-buffered TCM199 (mTCM199), 10 mmol/L HEPES-buffered Medium RD (mRD), and mTCM199 supplemented with fetal bovine serum fraction (mTCM199 + FBS fraction) that served as control. Cumulus-oocyte complexes were matured for 24 hours in three different media supplemented with follicle-stimulating hormone, estradiol-17β, and polyvinylpyrrolidone. Nuclear maturation of oocytes, their developmental competence into blastocysts after in vitro fertilization (IVF) and mitochondrial distribution in oocytes were investigated.<h4>Results</h4>There was no difference in the ratio of matured oocytes regardless of IVM media. The percentage of morula stage was higher in mRD than in mTCM199 group (<i>P</i> < .05) at 120-144 hours after IVF, although the blastocyst rates between groups were not significantly different at 168-216 hours. IVM in mRD increased the percentage of oocytes with diffused mitochondrial distribution compared with the immature and mTCM199 and had similar percentage of oocytes in mTCM199 + FBS fraction.<h4>Conclusions</h4>Medium RD would be useful as a chemically defined medium for IVM of bovine oocytes.Reproductive medicine and biologyUsefulness of modified Medium RD as a chemically defined medium for in vitro maturation of bovine oocytes.PMC7542018RMB01Momozawa KfalseUsefulness of modified Medium RD as a chemically defined medium for in vitro maturation of bovine oocytes.<h4>Purpose</h4>In the present study, I evaluated the usefulness of Medium RD, with mixed RPMI1640 and Dulbecco's modified Eagle's medium (1:1, v/v), as a chemically defined medium for in vitro maturation (IVM) of bovine oocytes.<h4>Methods</h4>In vitro maturation was performed in 10 mmol/L HEPES-buffered TCM199 (mTCM199), 10 mmol/L HEPES-buffered Medium RD (mRD), and mTCM199 supplemented with fetal bovine serum fraction (mTCM199 + FBS fraction) that served as control. Cumulus-oocyte complexes were matured for 24 hours in three different media supplemented with follicle-stimulating hormone, estradiol-17β, and polyvinylpyrrolidone. Nuclear maturation of oocytes, their developmental competence into blastocysts after in vitro fertilization (IVF) and mitochondrial distribution in oocytes were investigated.<h4>Results</h4>There was no difference in the ratio of matured oocytes regardless of IVM media. The percentage of morula stage was higher in mRD than in mTCM199 group (<i>P</i> < .05) at 120-144 hours after IVF, although the blastocyst rates between groups were not significantly different at 168-216 hours. IVM in mRD increased the percentage of oocytes with diffused mitochondrial distribution compared with the immature and mTCM199 and had similar percentage of oocytes in mTCM199 + FBS fraction.<h4>Conclusions</h4>Medium RD would be useful as a chemically defined medium for IVM of bovine oocytes.2020-01-01T00:00:00Z2020 Oct2025-04-06T19:30:18.644Z2025-04-06T19:30:18.644ZS-EPMC75420183307163810.1002/rmb2.12337