Osmolarity at early culture stage affects development and expression of apoptosis related genes (bax-α and bcl-xl) in pre-implantation porcine NT embryos

• Published in: Molecular reproduction and development Vol. 75; no. 3; pp. 464 - 471
• Main Authors: Hwang, In-Sun, Park, Mi-Rung, Moon, Hyo-Jin, Shim, Joo-Hyun, Kim, Dong-Hoon, Yang, Byoung-Chul, Ko, Yeoung-Gyu, Yang, Boh-Suk, Cheong, Hee-Tae, Im, Gi-Sun
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.03.2008; Wiley-Liss
• Subjects: Animals; apoptosis; Apoptosis - drug effects; Apoptosis - genetics; bcl-2-Associated X Protein - genetics; bcl-2-Associated X Protein - metabolism; bcl-X Protein - genetics; bcl-X Protein - metabolism; Biological and medical sciences; Biotechnology; Blastocyst - drug effects; Blastocyst - metabolism; Blastocyst - physiology; Cells, Cultured; Culture Media - pharmacology; Embryo Culture Techniques; Embryo, Mammalian; Embryonic Development - drug effects; Embryonic Development - genetics; Fertilization in Vitro; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Developmental; Gene transfer; Genetic engineering; Genetic technics; IVF; Methods. Procedures. Technologies; nuclear transfer; Osmolar Concentration; osmolarity; pig; Swine - embryology; Synthetic digonucleotides and genes. Sequencing; Time Factors; Water-Electrolyte Balance - physiology; Embryo; Fertilization; Osmolarity; Cell nucleus; Early stage; Gene expression; Pig; Vertebrata; Mammalia; Gene; Ovum implantation; Animal; Development; Transfer; IVF; Artiodactyla; nuclear transfer; Ungulata; Quantitative analysis; Apoptosis
• ISSN: 1040-452X; 1098-2795
• DOI: 10.1002/mrd.20785

This study examined whether high osmolarity of culture medium at the early culture stage affects development and expression of apoptosis related genes (Bax‐α and Bcl‐xl) of porcine nuclear transfer (NT) and in vitro fertilization (IVF) embryos. NT and IVF embryos were divided into three groups and the basic medium was PZM‐3 (260–270 mOsmol, control group). The control group of embryos was cultured in PZM‐3 for whole culture period. Other two groups of embryos were cultured in a modified PZM‐3 with 0.05 M sucrose (300–320 mOsmol, sucrose group) or increased NaCl to 138 mM (300–320 mOsmol, NaCl group) for the first 2 days, and then cultured in PZM‐3 for 4 days. NT embryos cultured in NaCl group showed a significantly higher developmental rate to the blastocyst stage with a decreased apoptosis rate compared to the control (P < 0.05). There was no difference in blastocyst formation and apoptosis incidence among the three culture treatments for IVF‐derived embryos. Bax‐α mRNA expression was significantly higher in the control than sucrose or NaCl group for both NT and IVF embryos (P < 0.05). Moreover, the relative abundance of Bax‐α/Bcl‐xl was higher in the control than the treatment groups. These results indicate that the higher osmolarity at the early embryonic stage of porcine NT and IVF embryos can improve the in vitro development with reduced apoptosis through regulating the Bax‐α/Bcl‐xl gene expression. Mol. Reprod. Dev. 75: 464–471, 2008. © 2007 Wiley‐Liss, Inc.