Gonadotropins, serum, and amino acids alter nuclear maturation, cumulus expansion, and oocyte morphology in hamster cumulus-oocyte complexes in vitro.
Glucose, lactate, and pyruvate (the substrate triad), gonadotropins, serum, and amino acids were tested on maturation of cumulus-oocyte complexes (COCs) using a simple defined medium, Tyrode's-PVA (T-PVA). In experiment 1, effects of FSH (2 microg/ml) and the substrate triad were tested using a 2 x 2 factorial design. After 12-13 h, nuclear maturation was depressed in the absence of the triad or with FSH (0-14% metaphase II [MII]) compared with the triad alone (92% MII, p < 0.05). Subsequent experiments used as the base medium Tyrode's solution with the triad (TLP-PVA): adding 10% bovine calf serum (BCS) and gonadotropins (10 microg/ml FSH, 10 microg/ml LH, or both) yielded nuclear maturation equivalent to that in medium alone (88-100% post-metaphase I [post-MI] oocytes). Responses with glutamine, or with 11 but not 20 amino acids, were equivalent to the response in BCS with gonadotropins (93-100% post-MI oocytes). Some cumulus expansion occurred in COCs matured with gonadotropins and BCS, or glutamine, or 11 amino acids, but was less extensive than for in vivo-matured COCs. Oocytes matured with gonadotropins and BCS, or glutamine, or 11 amino acids plus gonadotropins, but not medium alone, had normal-appearing first polar bodies. Another cytoplasmic marker, cortical distribution of microfilaments (detected by confocal microscopy), did not differ between in vitro- and in vivo-matured oocytes. We conclude that effects of gonadotropins on hamster nuclear maturation, cumulus expansion, and oocyte morphology are modulated by serum or amino acids; maturation conditions producing normal oocyte and cumulus morphologies are predicted to yield developmentally competent oocytes.
Kito
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Department of Animal Health and Biomedical Sciences, University of Wisconsin-Madison 53706, USA.
Bavister
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BD
D008841:Actin Cytoskeleton / Q000187:drug effects / Q000648:ultrastructure; D000596:Amino Acids / Q000494:pharmacology*; D000818:Animals; D001798:Blood Proteins / Q000494:pharmacology; D002417:Cattle; D002467:Cell Nucleus / Q000187:drug effects / Q000648:ultrastructure; D006224:Cricetinae; D003470:Culture Media / Q000737:chemistry; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D005947:Glucose / Q000494:pharmacology; D005973:Glutamine / Q000494:pharmacology; D066298:In Vitro Techniques; D019344:Lactic Acid / Q000494:pharmacology; D007986:Luteinizing Hormone / Q000494:pharmacology*; D008647:Mesocricetus; D009865:Oocytes / Q000187:drug effects* / Q000254:growth & development / Q000648:ultrastructure*; D019289:Pyruvic Acid / Q000494:pharmacology
D000596:Amino Acids; D001798:Blood Proteins; D003470:Culture Media; D005973:Glutamine; D019344:Lactic Acid; D019289:Pyruvic Acid; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D005947:Glucose