earticle

영어

This study was conducted to investigate the endoplasmic reticulum (ER) stress and subsequent apoptosis of porcine somatic cell nuclear transfer (SCNT) embryos induced during SCNT procedures, which compared with IVF embryos. Porcine SCNT embryos were made by micromanipulation and electrofusion/activation. Control porcine embryos were prepared by in vitro fertilization (IVF). Porcine SCNT and IVF embryos were sampled at 3 h-, and 20 h-post SCNT or IVF, and at the blastocyst stage for mRNA extraction. The x-box binding protein 1 (Xbp1) mRNA, the key transcription factor in the ER stress condition was confirmed by RT-PCR analysis. The expressions of ER stress-associated genes, the C/EBP homologous protein (CHOP), binding protein (BiP), activating transcription factor 4 (ATF4), and glucose-regulated protein 94 (GRP94) were confirmed by RT-qPCR. Apoptotic gene expression was analyzed by RT-PCR. Prior to SCNT, the splicing of Xbp1 mRNA and increased expressions of ER stress-associated genes were confirmed in the somatic cells treated with tunicamycin (TM), an ER stress inducer. Expression of spliced Xbp1 (Xbp1s) mRNA in the SCNT embryos did not differ with that of IVF embryos, regardless of the embryonic stage. Expression of ER stress-associated genes in SCNT embryos was, however, significantly increased in the all embryonic stages compared to IVF embryos (p<0.05). Apoptotic gene expression was slightly high in the SCNT embryos, but not different from that of IVF embryos in each group. The result of this study indicates that excessive ER stress can be induced by SCNT procedures. Although, ER stress-derived apoptosis was not identified in this study, more research studies are needed on the relationship between SCNT and ER stress-derived apoptosis.