Microdensitometric assay of enzymatic activities in parthenogenetically activated and in vitro fertilized bovine oocytes.
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.
Ferrandi
Bruno
B
Istituto di Anatomia degli Animali Domestici, Facoltà di Medicina Veterinaria, Università degli Studi di Milano, Italy. Bruno.Ferrandi@unimi.it
Cremonesi
Fausto
F
Consiglio
Anna Lange
AL
Luciano
Alberto Maria
AM
Gandolfi
Fulvio
F
Modina
Silvia
S
Carnevali
Antino
A
Porcelli
Franca
F
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
D004396:Coloring Agents; D007476:Ionophores; C001020:N(6),N(6)-dimethyladenine; D007770:L-Lactate Dehydrogenase; D005954:Glucosephosphate Dehydrogenase; D013385:Succinate Dehydrogenase; D000225:Adenine