title: In vitro culture conditions using chemically defined media for in vitro matured and intracytoplasmically inseminated porcine oocytes.
abstract: The present study investigated in vitro culture methods [droplet and Well of the Well (WOW)] using semi-defined and defined media [modified porcine zygote medium (mPZM)] and the additional effects of insulin on in vitro matured and intracytoplasmically inseminated porcine oocytes. In Experiment 1, in vitro matured and intracytoplasmically inseminated porcine oocytes were cultured for 6 days in the following four groups: 1) mPZM-3 (containing bovine serum albumin) + droplet (30 mul), 2) mPZM-3 + WOW, 3) mPZM-4 (containing polyvinyl alcohol) + droplet, and 4) mPZM-4+ WOW. The culture media (mPZM-3 and mPZM-4) and methods (droplet and WOW) did not significantly affect the cleavage rate, but the blastocyst rate of the oocytes cultured in mPZM-3 was significantly (P<0.01) higher than that of mPZM-4 (20.1 and 9.4%, respectively). The blastocyst rates as percentages of the cleaved oocytes (51.8 and 16.9%) and the hatched blastocyst rate as percentages of the number of blastocysts (12.3 and 2.2%) were also significantly (P<0.01) higher in mPZM-3 compared with those in mPZM-4. There was significant interaction (P<0.05) between the two main factors; the effects of the culture media and methods on the rate of hatched blasyocysts as percentages of the blastocysts produced and, the hatched blastocyst rate (20.3%) as percentages of the number of blastocysts produced in mPZM-3 were significantly (P<0.05) higher than in the other groups. In Experiment 2, the additional effects of insulin (100 ng/ml) in mPZM-3 and mPZM-4 media was investigated in the WOW culture system. Insulin addition did not improve cleavage, blastocyst formation, or the number of cells in blastocysts. However, as in Experiment 1, mPZM-3 resulted in a significantly higher blastocyst rate as percentages of the cleaved oocytes than mPZM-4 (33.9 and 18.4%). These results indicate that a chemically defined medium (mPZM-4) needs to be improved to provide more suitable culture conditions for in vitro development of in vitro matured and intracytoplasmically inseminated porcine oocytes. However, the WOW system may be a useful IVC method for blastocyst development of in vitro matured porcine oocytes following ICSI when a semi-defined medium (mPZM-3) is used.
authors.affiliation: Laboratory of Animal Reproduction, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan.
authors.forename: Chisato
authors.initials: C
authors.lastname: Kamiya
authors.forename: Mariko
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Fukui
mesh_terms: D000818:Animals; D002417:Cattle; D018929:Cell Culture Techniques / Q000379:methods*; D003470:Culture Media; D005260:Female; D007328:Insulin / Q000494:pharmacology; D008297:Male; D009865:Oocytes / Q000187:drug effects / Q000254:growth & development*; D011142:Polyvinyl Alcohol / Q000494:pharmacology; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D020554:Sperm Injections, Intracytoplasmic; D013552:Swine
chemical_list: D003470:Culture Media; D007328:Insulin; D012710:Serum Albumin, Bovine; D011142:Polyvinyl Alcohol