Generation of monkey offspring by SCNT using fibroblasts from a BMAL1 knockout monkey. (A) A schematic diagram depicting the procedure of generating BMAL1 knockout monkey clones. (B) Example images of monkey SCNT embryos at different stages; scale bar, 120 μm. (C) Images of B1–B5, five cloned cynomolgus monkeys generated by SCNT using fibroblasts from the BMAL1 knockout monkey A6. (D) BMAL1 mutation analysis on ear tissue from all five cloned monkeys, showing that four monkeys carry heterogeneous bi-allelic (−8/−8, +4, 2PM) and one carries homogeneous bi-allelic (−8/−8) mutation of the BMAL1 gene.