Effects of small molecules on gene expression in mouse nuclear transfer embryos at the 2 cell stage. Mus musculus

Animal cloning has been achieved in many species by transplanting differentiated cell nuclei to unfertilized oocytes. However, the low efficiencies of cloning have remained an unresolved issue. We find that the combination of two small molecules, trichostatin A (TSA) and vitamin C (VC), under culture condition with deionized bovine serum albumin (dBSA), dramatically improves the cloning efficiency in mice and 15% of cloned embryos develop to term by means of somatic cell nuclear transfer (SCNT). RNA-seq analyses of SCNT embryos at the 2-cell stage revealed that the treatment with TSA, followed by the VC treatment, resulted in the upregulated expression of the previously identified reprogramming-resistant genes. Moreover, the expression of 2-cell-specific retroelements was upregulated by the sequential treatment with TSA and VC. The best condition for reprogramming is to add TSA for 8 hours after nuclear transfer and then SCNT embryos are further cultured with VC for 7 hours. Overall design: Total RNA-seq of single mouse SCNT embryos treated with trichostatin A and/or vitamin C.