The ability to achieve meiotic maturation in the dog oocyte is linked to glycolysis and glutamine oxidation. Academic Article uri icon

abstract

  • We tested the hypothesis that meiotic competence of dog oocytes is tightly linked with donor follicle size and energy metabolism. Oocytes were recovered from small (<1mm diameter, n=327), medium (1-<2mm, n=292) or large (2mm, n=102) follicles, cultured for 0, 24, or 48hr, and then assessed for glycolysis, glucose oxidation, pyruvate uptake, glutamine oxidation, and nuclear status. More oocytes (P<0.05) from large follicles (37%) reached the metaphase-II (MII) stage than from the small group (11%), with the medium-sized class being intermediate (18%; P>0.05). Glycolytic rate increased (P<0.05) as oocytes progressed from the germinal vesicle (GV) to MII stage. After 48hr of culture, oocytes completing nuclear maturation had higher (P<0.05) glycolytic rates than those arrested at earlier stages. GV oocytes recovered from large follicle oocytes had higher (P<0.05) metabolism than those from smaller counterparts at culture onset. MII oocytes from large follicles oxidized more (P<0.05) glutamine than the same stage gametes recovered from smaller counterparts. In summary, larger-sized dog follicles contain a more metabolically active oocyte with a greater chance of achieving nuclear maturation in vitro. These findings demonstrate a significant role for energy metabolism in promoting dog oocyte maturation, information that will be useful for improving culture systems for rescuing intraovarian genetic material.

published proceedings

  • Mol Reprod Dev

altmetric score

  • 3

author list (cited authors)

  • Songsasen, N., Wesselowski, S., Carpenter, J. W., & Wildt, D. E.

citation count

  • 7

publication date

  • March 2012

publisher