title: The effect of supplementation of amino acids and taurine to modified KSOM culture medium on rat embryo development.
abstract: The rat is widely used as a laboratory animal for research. In particular, genetically engineered rats are essential for production of animal models of several diseases. Although embryo manipulation techniques are needed to produce them, such technology for rat preimplantation embryos is not as advanced as it is for mouse embryos. One reason is that in vitro culture systems for preimplantation embryos are limited in rats. Therefore, we intended to develop a new culture system for rat preimplantation embryos focusing on supplementation of amino acids as nutrition to the culture media. First, we found that taurine, glycine, glutamate, and alanine were abundant in the oviductal fluid of Wistar rats. The profile of taurine and these three amino acids was unchanged during the estrous cycle and from Days 0 to 3 of pregnancy (Day 0; vaginal plug was confirmed). Second, we assessed the effect of phosphate and phenol red on the development of rat zygotes and confirmed that they caused two-cell block. Third, we examined the effect of changing the medium on zygote development because addition of amino acids into culture medium causes ammonium accumulation, which is detrimental to embryo development. Blastocyst formation was suppressed in cultures with no medium change (P = 0.004; decreased to approximately one-fourth of that with medium change). Fourth, we examined the effect of supplementation of these three amino acids and taurine to modified potassium simplex optimized medium (KSOM). The zygote development rates were increased by the three amino acids and taurine in a concentration-dependent manner at 48, 72, and 96 hours (P = 0.001, 0.005, and 0.009, respectively) in culture. Finally, we confirmed that blastocysts cultured in modified KSOM had the capacity to develop to full term after implantation. These results showed that not only the supply of nutrients but also removal of wastes and toxicants is important for culture of rat preimplantation embryos.
authors.affiliation: Division of Laboratory Animal Science, Research Center for Bioscience and Technology, Tottori University, Yonago, Tottori, Japan. Electronic address: knakamura@med.tottori-u.ac.jp.
authors.forename: Kazuomi
authors.initials: K
authors.lastname: Nakamura
authors.affiliation: Division of Laboratory Animal Science, Research Center for Bioscience and Technology, Tottori University, Yonago, Tottori, Japan.
authors.forename: Kayoko
authors.initials: K
authors.lastname: Morimoto
authors.affiliation: Division of Laboratory Animal Science, Research Center for Bioscience and Technology, Tottori University, Yonago, Tottori, Japan; ATEC Corp., Nishinomiya, Hyogo, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Shima
authors.affiliation: Division of Laboratory Animal Science, Research Center for Bioscience and Technology, Tottori University, Yonago, Tottori, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Yoshimura
authors.affiliation: Chromosome Engineering Research Center (CERC), Tottori University, Yonago, Tottori, Japan; Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, Yonago, Tottori, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kazuki
authors.affiliation: Laboratory of Animal Models for Human Diseases, National Institutes of Biomedical Innovation, Health and Nutrition, Ibaraki, Osaka, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Suzuki
authors.affiliation: Laboratory of Animal Models for Human Diseases, National Institutes of Biomedical Innovation, Health and Nutrition, Ibaraki, Osaka, Japan.
authors.forename: Junichiro
authors.initials: J
authors.lastname: Matsuda
authors.affiliation: Division of Laboratory Animal Science, Research Center for Bioscience and Technology, Tottori University, Yonago, Tottori, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Ohbayashi
mesh_terms: D000596:Amino Acids / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D003470:Culture Media / Q000737:chemistry*; D004305:Dose-Response Relationship, Drug; D004624:Embryo Transfer; D004622:Embryo, Mammalian / Q000187:drug effects*; D005187:Fallopian Tubes; D005260:Female; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D013654:Taurine / Q000494:pharmacology*
chemical_list: D000596:Amino Acids; D003470:Culture Media; D013654:Taurine
keywords: Amino acid; Embryo culture; Oviductal fluid; Potassium simplex optimized medium; Rat