Development of a modified straw method for vitrification of in vitro-produced bovine blastocysts and various genes expression in between the methods

• Published in: Cryobiology Vol. 68; no. 1; pp. 57 - 64
• Main Authors: Ha, A-Na, Lee, Sang-Ryeul, Jeon, Jeong-Seon, Park, Han-Seul, Lee, Sang-Ho, Jin, Jong-In, Sessions, Benjamin R., Wang, Zhongde, White, Kenneth L., Kong, Il-Keun
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01.02.2014
• Subjects: Animals; bcl-2-Associated X Protein - genetics; bcl-2-Associated X Protein - metabolism; Blastocyst - cytology; Blastocyst - metabolism; Bovine; Caspase 3 - genetics; Caspase 3 - metabolism; Cattle; Embryo Transfer; Female; Fertilization in Vitro; Gene Expression; Golgi Apparatus - metabolism; IVP blastocysts; Male; Mitochondria - metabolism; Modified plastic straw loading method; Myeloid Cell Leukemia Sequence 1 Protein - genetics; Myeloid Cell Leukemia Sequence 1 Protein - metabolism; Peroxiredoxins - genetics; Peroxiredoxins - metabolism; Post-thaw viability; Superoxide Dismutase - genetics; Superoxide Dismutase - metabolism; Vitrification; Post-thaw viability; Bovine; Vitrification; IVP blastocysts; Modified plastic straw loading method
• ISSN: 0011-2240; 1090-2392
• DOI: 10.1016/j.cryobiol.2013.11.007

This study evaluated a modified plastic straw loading method for vitrification of in vitro-produced bovine blastocysts. A modified straw was used with a depressed area on its inner surface to which embryos attach. In vitro-produced blastocysts were randomly assigned into three groups: (i) blastocysts attached to the inner surface of a plastic straw (aV), (ii) blastocysts attached to the inner surface of a modified plastic straw (maV), and (iii) non-vitrified blastocysts (control). The recovery rates were not significantly different between aV and maV groups (95.8% vs. 94.3%). The post-thaw survival rate did not significantly differ between aV and maV groups (86.4% vs. 88.2%). The total cell numbers of blastocyst was higher in control than in aV and maV groups (142±21.8 vs. 117±29.7 and 120±25.2; P<0.05), but not significantly differ between aV and maV groups. The mRNA levels of pro-apoptosis related genes Bax and Caspase-3 were higher in aV and maV than in control (P<0.05). By contrast, the mRNA levels of anti-apoptotic genes Bcl-2 and Mcl-1 and of antioxidant-related genes MnSOD and Prdx5 were lower in aV and maV than in control (P<0.05). Confocal microscopy analysis of Golgi apparatus and mitochondria showed that the fluorescence intensity of Golgi apparatus and mitochondria was higher in control than in aV and maV groups. In conclusion, both aV and maV methods can be used to successfully vitrify IVP blastocysts, with maV method to be preferable because of its easiness in embryo loading.