248 ALTERED GENE EXPRESSION PROFILES IN PIG scNT-DERIVED UMBILICAL CORD

Abstract

Despite numerous studies performed on somatic cell cloned (scNT) animals, the factors behind the anomalies such as overgrowth, placental malformations, and heart failure remain unknown. These observations provide a cautionary note about the safety of current cloning procedures. Ovaries were collected from pubertal gilts at a local slaughterhouse, and oocytes with evenly granulated cytoplasm surrounded by at least three uniform layers of compact cumulus cells were selected and cultured in NCSU-23 medium. A single donor cell was injected into the perivitelline space of each egg and then electrically fused. Approximately 200 scNT embryos were transferred into the oviduct of each recipient. In the study, we generated 58 somatic cell cloned (scNT) piglets. Of these, six scNT piglets displayed severe abnormalities in several organs due to severe disruption of two umbilical cord arteries. Histologically, there was evidence of severe calcification in the kidney and placenta, peliosis in the sinusolidal space of the liver, abnormal stroma cell proliferation in lung, and tubular degeneration as a result of ischemic change due to lung congestion. To determine the genes responsible for disruption of umbilical cord arteries, a pig 13 K oligo cDNA microarray, developed in-house at GenoCheck Co., Ltd. (Ansan, Korea), was used for gene expression profiling studies. In scNT piglets that have severe disruption in the arteries of umbilical cord, 23 genes were up-regulated, but 127 genes were down-regulated, especially angiogenesis-related genes (VEGFa, PLANH1, CYR61, and SMAD4), cytoskeleton-related genes (14-3-3E, CCT3, DCTN1, KRT7, and MARK4), and hypoxia-related genes (HIG2 and DDIT4). These scNT piglets were chronically exposed to maternal and fetal blood circulation problems and, as a result, they died within the first week of life. The histological findings in this study have not been reported previously in scNT animals and demonstrate a possible correlation between early death of scNT clones and abnormality of two umbilical cord arteries.