Longevity & AgingMarmoset cloning breakthrough yields stem cells from cloned embryos for the first time
Marmosets are a key non-human primate model, but cloned marmoset embryos have never developed past the 8-cell stage. This study combined three epigenetic treatments: trichostatin A (TSA), injection of Kdm4d mRNA (which removes the repressive H3K9me3 mark), and a G9a/EHMT2 inhibitor. With them, cloned embryos reached the blastocyst stage at about 14–15% per embryo from fibroblast donors. The team then derived nuclear transfer embryonic stem cell (ntESC) lines, including wild-type and GFP-transgenic ones. The lines had normal karyotypes and were pluripotent. DNA analysis confirmed nuclear donor origin and recipient-oocyte mitochondria. Transcriptome analysis showed residual abnormal gene expression, particularly in translation and ribosome-related genes, so reprogramming remains incomplete.