Cover Story :
Based on the results obtained for the studies of in vitro development of cloned embryos, epigenetic modifications have been widely used for cloning farm animals. However, such studies remain few in canids because of the lack of optimal in vitro oocyte maturation, embryo culture, and superovulation system. Kim et al. investigated whether a histone deacetylase inhibitor used in dog to pig interspecies somatic cell nuclear transfer (iSCNT), which improves nuclear reprogramming, could be used in dog cloning (Kim et al.: Suberoylanilide hydroxamic acid during in vitro culture improves development of dog-pig interspecies cloned embryos but not dog cloned embryos. p. 277–282). Porcine oocytes supported reprogramming of nuclei from dog fibroblasts up to early developmental stage of iSCNT embryos, and treating the embryos with suberoylanilide hydroxamic acid (SAHA) increased their developmental competence. However, unfortunately, SAHA treatment for dog to pig iSCNT embryos was not sufficient to improve their in vivo development because three and one clones were successfully produced from the control and SAHA treated groups, respectively.