title: The beneficial effects of reduced magnesium during the oocyte-to-embryo transition are conserved in mice, domestic cats and humans.
abstract: In many cell types Mg2+ can antagonise Ca2+ -stimulated signalling pathways, but information regarding the effects of these ions on IVF and subsequent embryonic development is limited. Our objectives were to evaluate the effects of Mg2+ in the IVF medium on embryonic development in mice and then determine if similar effects occurred in domestic cats and humans. Oocytes from hybrid and outbred mice, domestic cats and humans were fertilised (IVF, mice and cats; intracytoplasmic sperm injection (ICSI), humans) in the presence of 0.2 or 1.2 (mouse and human) or 1.0 (cat) mM Mg2+ and the resulting embryos were cultured to the blastocyst stage. Decreased concentrations of Mg2+ during IVF increased (P<0.05) cleavage of oocytes from outbred mice (77.9 vs. 51.0%), development of embryos from hybrid mice (74.5 vs. 51.0% hatching blastocyst per cleaved embryo) and both cleavage (68.4 vs. 46.8%) and blastocyst development (53.0 vs. 26.2% per cleaved embryo) in cats. Development to the blastocyst stage (52.1 vs. 40.2%) was also improved (P<0.05) when ICSI was performed on human oocytes in the presence of 0.2 mM Mg2+, compared with a commercial culture medium. Sensitivity to increased (1.0 to 1.2 mM) concentrations of Mg2+ in the medium during the oocyte-to-embryo transition appears to be conserved in three different species.
authors.affiliation: National Foundation for Fertility Research, 10290 RidgeGate Cr., Lone Tree, CO 80124, USA.
authors.forename: Jason R
authors.initials: JR
authors.lastname: Herrick
authors.affiliation: National Foundation for Fertility Research, 10290 RidgeGate Cr., Lone Tree, CO 80124, USA.
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Strauss
authors.affiliation: Fertility Laboratories of Colorado, 10290 RidgeGate Cr., Lone Tree, CO 80124, USA.
authors.forename: Ann
authors.initials: A
authors.lastname: Schneiderman
authors.affiliation: Fertility Laboratories of Colorado, 10290 RidgeGate Cr., Lone Tree, CO 80124, USA.
authors.forename: Mary
authors.initials: M
authors.lastname: Rawlins
authors.affiliation: Fertility Laboratories of Colorado, 10290 RidgeGate Cr., Lone Tree, CO 80124, USA.
authors.forename: John
authors.initials: J
authors.lastname: Stevens
authors.affiliation: Colorado Center for Reproductive Medicine, 10290 RidgeGate Cr., Lone Tree, CO 80124, USA.
authors.forename: William B
authors.initials: WB
authors.lastname: Schoolcraft
authors.affiliation: National Foundation for Fertility Research, 10290 RidgeGate Cr., Lone Tree, CO 80124, USA.
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Krisher
mesh_terms: D000818:Animals; D020013:Calcium Signaling / Q000502:physiology*; D002415:Cats; D003470:Culture Media / Q000378:metabolism; D046149:Embryo Culture Techniques / Q000379:methods*; D047108:Embryonic Development / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D059471:In Vitro Oocyte Maturation Techniques / Q000379:methods*; D016014:Linear Models; D008274:Magnesium / Q000378:metabolism* / Q000494:pharmacology; D051379:Mice; D011446:Prospective Studies; D027724:Reproductive Techniques, Assisted; D013045:Species Specificity
chemical_list: D003470:Culture Media; D008274:Magnesium