title: Effect of medium variations (zinc supplementation during oocyte maturation, perifertilization pH, and embryo culture protein source) on equine embryo development after intracytoplasmic sperm injection.
abstract: Prospective studies were conducted to help define procedural factors affecting in vitro embryo production via intracytoplasmic sperm injection (ICSI) of equine oocytes. In experiment 1, use of 10% fetal bovine serum as a protein source in embryo culture medium resulted in a higher blastocyst rate than did use of a combination of 3% fetal bovine serum, 3% equine preovulatory follicular fluid, and 4% human serum substitute (37% vs. 15%, respectively, P < 0.05). In experiment 2, the effect of zinc supplementation (0, 0.5, 1, or 1.5 μg/mL) during IVM was examined. There were no significant differences in rates of cleavage or blastocyst development (20%-31%). However, the proportion of blastocysts that developed on Day 7 for the added-zinc treatments was significantly higher than that for the control treatment (45% vs. 8%). In experiment 3, we tested whether use of high-pH medium (pH 8.0-8.4) during ICSI procedures would improve blastocyst rate when sperm with low cleavage rates after ICSI was used. When high-pH conditions were used for sperm preparation and also for the first 2 hours of incubation of injected oocytes after ICSI, the cleavage rate was unaffected but no blastocysts developed (0% vs. 24% for control). When high-pH conditions were used for sperm preparation only, the blastocyst rate was 37%. This was repeated using sperm from a second stallion; there was no significant difference in cleavage or blastocyst rates between sperm preparation in high pH vs. control medium. These findings add to our knowledge of factors affecting in vitro production of equine embryos.
authors.affiliation: Department of Veterinary Physiology & Pharmacology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX. Electronic address: yhchoi@cvm.tamu.edu.
authors.forename: Young-Ho
authors.initials: YH
authors.lastname: Choi
authors.affiliation: Department of Veterinary Physiology & Pharmacology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX.
authors.forename: John R
authors.initials: JR
authors.lastname: Gibbons
authors.affiliation: Department of Veterinary Physiology & Pharmacology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX.
authors.forename: Heloísa S
authors.initials: HS
authors.lastname: Canesin
authors.affiliation: Department of Veterinary Physiology & Pharmacology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX.
authors.forename: Katrin
authors.initials: K
authors.lastname: Hinrichs
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000502:physiology; D003470:Culture Media; D004305:Dose-Response Relationship, Drug; D046149:Embryo Culture Techniques / Q000662:veterinary*; D005260:Female; D006736:Horses / Q000196:embryology*; D006863:Hydrogen-Ion Concentration; D059471:In Vitro Oocyte Maturation Techniques / Q000662:veterinary*; D008297:Male; D020554:Sperm Injections, Intracytoplasmic / Q000662:veterinary*; D013094:Spermatozoa / Q000502:physiology; D015032:Zinc / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D003470:Culture Media; D015032:Zinc
keywords: Embryo; Horse; Intracytoplasmic sperm injection; Oocyte