In vitro oocyte maturation in a medium containing reduced sodium chloride improves the developmental competence of pig oocytes after parthenogenesis and somatic cell nuclear transfer.
The present study investigated the effects of IVM in hypotonic medium containing reduced (61.6mM) NaCl compared with isotonic medium containing 108.0mM NaCl (designated L and N respectively) on oocyte maturation and embryonic development in pigs. IVM culture was divided into four periods at 11-h intervals. Oocytes cultured in N for 33h and then in L for 11h of IVM (N-N-N-L) showed significantly improved (P<0.05) nuclear maturation of oocytes (75.4-79.0% vs 60.2-85.8%) and blastocyst formation (61.5-66.1% vs 45.2-67.5%) after parthenogenesis (PA) compared with other treatments (L-L-L-L, L-L-L-N, L-L-N-L, N-N-L-L, N-N-L-N, L-L-N-L, L-N-N-L and N-L-N-L). Oocytes matured in L-L-L-L and N-N-N-L had an increased (P<0.05) perivitelline space (11.0-12.5 vs 5.5µm) and intraoocyte reduced glutathione (GSH) content (1.39-1.41 vs 1.00 pixels per oocyte) relative to oocytes matured in N-N-N-N. Somatic cell nuclear transfer (SCNT) embryos derived from the N-N-N-L treatment had significantly (P<0.05) higher blastocyst formation (53.5%) than embryos derived from Medium-199 (37.4%) and N-N-N-N (41.8%) treatments. Overall, the results demonstrate that maturation of pig oocytes in hypotonic medium with reduced NaCl during the last 11h of IVM increases the developmental competence of oocytes after PA and SCNT by improving the cytoplasmic microenvironment, including an increased GSH content in IVM oocytes.
Laboratory of Theriogenology, College of Veterinary Medicine, Kangwon National University, Chuncheon, Gangwon 24341, Korea.
Joohyeong
J
Lee
Laboratory of Theriogenology, College of Veterinary Medicine, Kangwon National University, Chuncheon, Gangwon 24341, Korea.
Hanna
H
Lee
Laboratory of Theriogenology, College of Veterinary Medicine, Kangwon National University, Chuncheon, Gangwon 24341, Korea.
Yongjin
Y
Lee
Laboratory of Theriogenology, College of Veterinary Medicine, Kangwon National University, Chuncheon, Gangwon 24341, Korea.
Bola
B
Park
Laboratory of Theriogenology, College of Veterinary Medicine, Kangwon National University, Chuncheon, Gangwon 24341, Korea.
Fazle
F
Elahi
Division of Applied Animal Science, College of Animal Life Science, Kangwon National University, Chuncheon, Gangwon 24341, Korea.
Seung Tae
ST
Lee
Division of Applied Animal Science, College of Animal Life Science, Kangwon National University, Chuncheon, Gangwon 24341, Korea.
Choon-Keun
CK
Park
Laboratory of Veterinary Embryology and Biotechnology, College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 28644, Korea.
Sang-Hwan
SH
Hyun
Laboratory of Theriogenology, College of Veterinary Medicine, Kangwon National University, Chuncheon, Gangwon 24341, Korea.
Eunsong
E
Lee
D000818:Animals; D003470:Culture Media / Q000737:chemistry*; D046149:Embryo Culture Techniques / Q000379:methods / Q000662:veterinary; D047108:Embryonic Development / Q000502:physiology; D005260:Female; D005978:Glutathione / Q000378:metabolism; D059471:In Vitro Oocyte Maturation Techniques / Q000379:methods / Q000662:veterinary*; D053652:Nuclear Transfer Techniques / Q000662:veterinary*; D009865:Oocytes / Q000254:growth & development* / Q000378:metabolism; D010312:Parthenogenesis / Q000502:physiology*; D012965:Sodium Chloride / Q000032:analysis*; D013552:Swine
D003470:Culture Media; D012965:Sodium Chloride; D005978:Glutathione