title: Microdensitometric assay of enzymatic activities in parthenogenetically activated and in vitro fertilized bovine oocytes.
abstract: To examine the paternal genome's role in reprogramming metabolic activity in one-cell embryos, we investigated metabolic aspects of bovine oocytes after in vitro maturation and in vitro fertilization and after in vitro parthenogenetic activation with a Ca2+ ionophore and 6-dimethylaminopurine. We assayed succinate dehydrogenase, lactate dehydrogenase and glucose-6-phosphate dehydrogenase activities by microspectrophotometry in immature oocytes and oocytes after maturation, in vitro fertilization and parthenogenetic activation. Succinate dehydrogenase activity significantly increased after in vitro maturation, significantly decreased after Ca2+ ionophore activation and further decreased after 6-dimethylaminopurine treatment. Lactate dehydrogenase activity showed a significant decrease in bovine oocytes after in vitro maturation, remained unchanged in Ca2+ ionophore-treated oocytes and rose significantly after 6-dimethylaminopurine treatment. This activity was dramatically reduced after in vitro fertilization, reaching absorbance levels that were not different from those in mature and Ca2+ ionophore-treated oocytes. Glucose-6-phosphate dehydrogenase activity was significantly lower in matured oocytes as compared to immature oocytes, was significantly higher after artificial activation with Ca2+ ionophore and remained constant after 6-dimethylaminopurine treatment or after in vitro fertilization. We suggest that metabolic changes involved in parthenogenetic activation are similar to those occurring after fertilization.
authors.affiliation: Istituto di Anatomia degli Animali Domestici, Facoltà di Medicina Veterinaria, Università degli Studi di Milano, Italy. Bruno.Ferrandi@unimi.it
authors.forename: Bruno
authors.initials: B
authors.lastname: Ferrandi
authors.forename: Fausto
authors.initials: F
authors.lastname: Cremonesi
authors.forename: Anna Lange
authors.initials: AL
authors.lastname: Consiglio
authors.forename: Alberto Maria
authors.initials: AM
authors.lastname: Luciano
authors.forename: Fulvio
authors.initials: F
authors.lastname: Gandolfi
authors.forename: Silvia
authors.initials: S
authors.lastname: Modina
authors.forename: Antino
authors.initials: A
authors.lastname: Carnevali
authors.forename: Franca
authors.initials: F
authors.lastname: Porcelli
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D002417:Cattle; D004396:Coloring Agents; D003720:Densitometry; D005260:Female; D005307:Fertilization in Vitro; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D007476:Ionophores / Q000494:pharmacology; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008297:Male; D009865:Oocytes / Q000201:enzymology* / Q000648:ultrastructure; D010312:Parthenogenesis / Q000502:physiology*; D011247:Pregnancy; D013385:Succinate Dehydrogenase / Q000378:metabolism
chemical_list: D004396:Coloring Agents; D007476:Ionophores; C001020:N(6),N(6)-dimethyladenine; D007770:L-Lactate Dehydrogenase; D005954:Glucosephosphate Dehydrogenase; D013385:Succinate Dehydrogenase; D000225:Adenine