Abstract: O-linked β-N-Acetylglucosamine Glycosylation (O-GlcNAc) is one of the main types of glycosylation in mammalian cells while Glucosamine (GlcN) is an O-GlcNAc substrate. Thus, effects of GlcN on the embryonic development, level of O-GlcNAc and related gene expression of buffalo embryos were examined in this study. Buffalo zygotes derived from In Vitro Fertilization (IVF) were randomly allocated into culture in the medium supplemented with different concentration of GlcN (0, 1, 2 and 4 mM) during the different culture period (0-72, 72-172 and 0-172 h). When GlcN was added to the medium in the culture period of 0-72 h after IVF, addition of 2 mM GlcN resulted in more zygotes developing to blastocysts (26.1%) in comparison with control (14.3%), 1 mM (13.6%) and 4 mM (11.3%) groups (p<0.05). However, the blastocyst yield decreased gradually when GlcN was added to the medium during 72-172 h of culture and decreased significantly when the concentration of GlcN was arrived at 4 mM (3.1 vs. 14.2%, p<0.05). When GlcN was added to the medium in the whole culture period (0-172 h) there were no significant difference in either cleavage rate or blastocyst yield among the four groups (p>0.05). Immunofluorescence analysis revealed that addition of 2 mM GlcN to medium from 0-72 h after IVF resulted in a significant increase (p<0.05) in the O-GlcNAc level of embryos at 2, 4, 8 cells and morula stage with the exception of blastocysts. QRT-PCR revealed that culture of zygotes with 2 mM GlcN in the culture period of 0-72 h after IVF resulted in a significant increase (p<0.05) in the expression of O-GlcNAc transferase gene in the embryos at the 2, 4, 8 cells and morula stage and did not affect the expression of O-GlcNAc-selective N-acetyl β-D-glucosaminidase gene. These results indicate that appropriate concentration of GlcN can improve the development of buffalo embryos and this action is stage dependent and mediated by O-GlcNAc transferase gene.
Nan Li, Fenghua Lu, Peng Zhu, Qingyou Liu, Jiangrong Jiang and Deshun Shi, 2013. Effects of Glucosamine on the Development and Related Gene Expression of Buffalo (Bubalus bubalis) Embryos. Journal of Animal and Veterinary Advances, 12: 394-401.