The effect of temperature during liquid storage of in vitro-matured bovine oocytes on subsequent embryo development.
The aim of the present study was to optimize the temperature for the temporal storage of matured bovine oocytes. In vitro-matured bovine oocytes were preserved in HEPES-buffered TCM199 medium supplemented with 10% newborn calf serum at different temperatures (4 °C, 15 °C, 25 °C, and 38.5 °C) for 20 hours. Embryo development and blastocyst quality after in vitro fertilization, cytoplasmic ATP and glutathione levels in oocytes, and the frequency of apoptotic oocytes were compared among storage groups and a control group without storage. Among the storage groups, those at 25 °C and 38.5 °C showed the highest rates of blastocyst development (19.3% and 24.5%, respectively) compared with those stored at 4 °C and 15 °C (8.5% and 14.9%, respectively); however, blastocyst formation rates in all storage groups were lower than that in the control group (39.8%; P < 0.05). Storage at 38.5 °C and 15 °C was associated with reduced cell numbers in resultant blastocysts compared with the control and the 25 °C storage groups. Storage at 4 °C reduced metabolic activity of oocytes characterized by their lower ATP levels compared with the other groups. Storage for 20 hours significantly reduced the glutathione content in oocytes in all groups in a similar manner, irrespective of the temperature. Storage at 4 °C or 15 °C but not at 25 °C and 38.5 °C significantly increased the percentage of apoptotic oocytes compared with the control group. In conclusion, 25 °C was found to be the most suitable temperature for the temporal storage of matured bovine oocytes regarding both the developmental competence of oocytes and the quality of resultant blastocysts.
Animal Breeding and Reproduction Research Division, NARO Institute of Livestock and Grassland Science, Tsukuba, Japan; Embryo Technology and Stem Cell Research Center, Suranaree University of Technology, Nakhon Ratchasima, Thailand.
Tayita
T
Suttirojpattana
Animal Breeding and Reproduction Research Division, NARO Institute of Livestock and Grassland Science, Tsukuba, Japan. Electronic address: somfai@affrc.go.jp.
Tamas
T
Somfai
Animal Breeding and Reproduction Research Division, NARO Institute of Livestock and Grassland Science, Tsukuba, Japan.
Satoko
S
Matoba
Food and Fertilizer Technology Center, Taipei, Taiwan; Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, Korea.
Takashi
T
Nagai
Embryo Technology and Stem Cell Research Center, Suranaree University of Technology, Nakhon Ratchasima, Thailand. Electronic address: rangsun@g.sut.ac.th.
Rangsun
R
Parnpai
Animal Breeding and Reproduction Research Division, NARO Institute of Livestock and Grassland Science, Tsukuba, Japan.
Masaya
M
Geshi
D000255:Adenosine Triphosphate / Q000032:analysis; D000818:Animals; D017209:Apoptosis; D001755:Blastocyst / Q000502:physiology; D002417:Cattle; D046149:Embryo Culture Techniques / Q000662:veterinary; D047108:Embryonic Development / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro / Q000662:veterinary; D005978:Glutathione / Q000032:analysis; D059471:In Vitro Oocyte Maturation Techniques / Q000379:methods*; D009865:Oocytes / Q000737:chemistry / Q000502:physiology; D013696:Temperature
D000255:Adenosine Triphosphate; D005978:Glutathione
Aging; Bovine; Oocyte; Storage; Temperature