202 KNOCK-DOWN AND DEVELOPMENTAL EFFICIENCY OF Arhgap15 GENE KNOCK-DOWN EMBRYOS

Abstract

The technique of RNA interference (RNAi) knock-down is a powerful tool for the analysis of gene function in mammalian cells and eggs. Rho GTPase-activating protein 15 (Arhgap15) is closely related to anaemia and immunity, especially as caused by trypanosome. This study was performed to investigate the effect of Arhgap15 gene knock-down on the developmental competence of bovine embryos in vitro. Bovine fibroblast cells were treated with 50 and 100 nM concentrations of Arhgap15 RNAi, respectively. After 24 h of transfection, the control group showed no change in Arhgap15 mRNA level, whereas mRNA expression in the RNAi-treated donor cells was obviously decreased in a dose-dependent manner. These RNAi-treated cells were then transferred into enucleated bovine oocytes to analyse the consequence of RNAi-mediated Arhgap15 gene knock-down. In the control group, cleavage and blastocyst development rates were 75% (102/136) and 14.7% (20/136), whereas those in the knock-down embryos were 81.6% (120/147) and 24.5% (36/147), respectively. The occurrence of cell death by apoptosis was examined in Day 7 blastocysts. Apoptotic cells numbered 12 ± 3.2 in control embryos and 8.9 ± 4.8 in knock-down embryos. Therefore, it can be concluded that RNAi-mediated Arhgap15 gene knock-down in somatic cells did not affect the developmental competence of bovine cloned embryos.