Effect of macromolecule supplementation during in vitro maturation of goat oocytes on developmental potential

In vitro maturation (IVM) of goat oocytes with serum-supplemented media results in oocytes with reduced developmental potential. The objective of this study was to develop a defined medium for IVM of goat oocytes that better supports subsequent embryonic development. Cumulus oocyte complexes (COC) were matured for 18-20 hr in: Experiment (1), tissue culture medium 199 (TCM199) with 10% (v/v) goat serum or modified synthetic oviduct fluid maturation medium (mSOFmat) with 2.5, 8.0, or 20.0 mg/ml bovine serum albumin (BSA); Experiment (2), mSOFmat with 4.0, 8.0, 12.0, or 16.0 mg/ml BSA; or Experiment (3), 1.0 mg/ml polyvinyl alcohol (PVA; control), 4.0 mg/ml BSA, 0.5 mg/ ml hyaluronate plus 0.5 mM citrate, or hyaluronate, citrate, and BSA. Mature COC were coincubated for 20-22 hr with 12-15 × 106 sperm/ml in modified Brackett and Oliphant (mBO) medium. Embryos were cultured for a total of 7 days in G1/2, and evaluated for cleavage, and blastocyst development, hatching, and total cell numbers. In the first experiment, more (P \u3c 0.05) blastocysts developed per cleaved embryo following maturation in mSOFmat with 2.5 or 8.0 mg/ ml BSA than with 20.0 mg/ml BSA or TCM199 with 10% goat serum. The various concentrations of BSA used in the second experiment did not affect (P \u3e 0.05) any of the developmental endpoints examined. In the third experiment, developmental potential of oocytes matured with PVA or hyaluronate with citrate was not different (P \u3e 0.05) from oocytes matured in the presence of BSA. These results demonstrate that developmentally competent goat oocytes can be matured under defined conditions. © 2004 Wiley-Liss, Inc