37 RESTORING REPROGRAMMING ABNORMALITIES IN A CLONED DOG HAVING ECTOPIC LIVER AND GALL BLADDER BY RECLONING

Abstract

The risk of reprogramming abnormalities such as placental hyperdevelopment, excessive fetal growth, or abnormalities of the immune system in cloned neonates is one of the major concerns in cloning research. However, until now, relatively few studies about birth defects have been reported in dog cloning, which might be due to the short in vitro manipulated procedure in this species. Here, we report a cloned dog having abnormal liver and investigated whether the abnormal liver was due to genetic modification. A cloned beagle was produced from a fibroblast derived from a 10-year-old donor, but accidentally died due to cannibalism of a nanny dog on the day of birth. During autopsy, an abnormal liver structure was found; 7 lobes were presented at the normal liver position inside the abdomen, but there was no gall bladder. Interestingly, 3 additional lobes with a gall bladder were found in between the rib and the skin. There were no other macroscopic anomalies observed in this puppy. To evaluate the heredity of this liver abnormality, the liver structure of the donor dog was diagnosed by computed tomography (CT). Also, to assess the possibility of restoring the liver abnormality, recloning was performed using a fibroblast cell line established from the dead pup, and liver positions in the recloned dogs were diagnosed by CT after puberty. In results, 2 recipients delivered 5 recloned dogs with birthweights of 510, 250, 460, 400, and 410 g. The smallest one showed severe bow-legged phenotype in its hind leg, and a unique coat pattern that showed the largest white coat surface. The pup died 10 days after birth, and no other abnormal phenotype was found during autopsy. The other 4 pups showed normal morphology at birth. The CT results showed normal positioning of the liver and gall bladder in all experimental dogs, including the original cell donor dog and recloned dogs. To our knowledge, there have been no reported cases of an ectopic liver and gall bladder present between rib and skin in both cloned and noncloned animals, and we consider that these abnormalities are not a due to genetic cause. Further studies regarding aberrant epigenetic reprogramming in the abnormal liver formation are needed.