title: Hyperglycemia-induced apoptosis affects sex ratio of bovine and murine preimplantation embryos.
abstract: The effect of glucose in the medium used during in vitro culture on both cell death by apoptosis and the sex ratio of bovine blastocysts derived from in vitro-matured and in vitro-fertilized oocytes was evaluated. Oocytes were matured, inseminated, and cultured in vitro in mSOF medium with 10% FCS with or without glucose supplementation. Exposure to high concentrations of glucose (10, 20, and 30 mM) during bovine embryo development in vitro from zygote to blastocyst resulted in a decrease in the number of cells per embryo and an increase in the frequency of apoptotic cells. A significantly higher proportion of females was found among those embryos that developed under hyperglycemic conditions in vitro. Moreover, both murine and bovine blastocysts incubated for 6 hr in 20 mM glucose had a significantly higher number of apoptotic cells in comparison to control. In this study, we also determined whether blastocyst production of the X-linked inhibitor of apoptosis protein (XIAP) differs between the sexes. Our results show that female bovine blastocysts produce significantly higher amounts of XIAP mRNA than males and this could be crucial in explaining the higher proportion of female blastocysts observed following in vitro culture under hyperglycemic conditions which induce apoptosis. Moreover, a higher proportion of female murine blastocysts cultured under hyperglycemic conditions were implanted in the uterus (65.3 of implantations from embryos cultured with 20 mM of glucose are females vs. 49% in control). This mechanism provides an explanation for the significant reduction of male children born to diabetic mothers.
authors.affiliation: Departamento de Reproducción Animal y Conservación de Recursos Zoogenéticos, INIA, Ctra de la Coruña Km 5.9, 28040 Madrid, Spain.
authors.forename: Adela
authors.initials: A
authors.lastname: Jiménez
authors.forename: Ninoska
authors.initials: N
authors.lastname: Madrid-Bury
authors.forename: Raúl
authors.initials: R
authors.lastname: Fernández
authors.forename: Sonia
authors.initials: S
authors.lastname: Pérez-Garnelo
authors.forename: Pedro
authors.initials: P
authors.lastname: Moreira
authors.forename: Belén
authors.initials: B
authors.lastname: Pintado
authors.forename: Julio
authors.initials: J
authors.lastname: de la Fuente
authors.forename: Alfonso
authors.initials: A
authors.lastname: Gutiérrez-Adán
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D001755:Blastocyst / Q000378:metabolism*; D002417:Cattle; D002452:Cell Count; D005260:Female; D006943:Hyperglycemia / Q000378:metabolism*; D020287:In Situ Nick-End Labeling; D008297:Male; D051379:Mice; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics; D012744:Sex Ratio; D051636:X-Linked Inhibitor of Apoptosis Protein
chemical_list: D011506:Proteins; D051636:X-Linked Inhibitor of Apoptosis Protein