On 2014 Jun 18, Madhusudana Girija Sanal commented:

This paper in Nature Genetics - 38, 1323 – 1328, 2006 is rather "unique" in its findings. I wonder someone has made similar observations/reproduced these results in the past 8 years (2014)! Even the original observations by Briggs (Phili) and King (Bronx, New York) suggest nucleus from immature (less differentiated) cells are better for SCNT compared to more mature (or differentiated) cells. In their classic experiments in frogs they used nucleus from early embryonic cells to perform SCNT. Refer Briggs Robert, and King Thomas Joseph. “The transplantation of living nuclei from blastula cells into enucleated frogs’ eggs.” Proceedings of the National Academy of Sciences 38 (1952): 455–463. However later many tried with nucleus from more mature frog cells but failed. In 1958, Gurdon (Oxford,UK), successfully cloned a frog using intact nuclei from the somatic cells (gut epitheial cells) of a tadpole and won the Nobel prize together with Yamanaka. These experiments are well documented and part of the history. Going by logic one would think, reprogramming an immature cell is easier compared to a differentiated and mature cell which has undergone extensive epigenetic rearrangements and condensation of chromosomes. It is also reported that generating iPSC or embryonic cells through SCNT from older adults is more difficult compared to infants or children. Moreover, isolation, purification of haematopoietic stem cells by FACS or Magnetic beads (involving seven markers) might have damaged these cells more compared to granulocytes which were isolated by anti-Gr-1 and scatter. The abundance and ease of isolation of granulocytes might have contributed to this observation which was interpreted by the authors as suggested by the title "Differentiated cells are more efficient than adult stem cells for cloning by somatic cell nuclear transfer"!

On 2014 Jun 18, Madhusudana Girija Sanal commented:

This paper in Nature Genetics - 38, 1323 – 1328, 2006 is rather "unique" in its findings. I wonder someone has made similar observations/reproduced these results in the past 8 years (2014)! Even the original observations by Briggs (Phili) and King (Bronx, New York) suggest nucleus from immature (less differentiated) cells are better for SCNT compared to more mature (or differentiated) cells. In their classic experiments in frogs they used nucleus from early embryonic cells to perform SCNT. Refer Briggs Robert, and King Thomas Joseph. “The transplantation of living nuclei from blastula cells into enucleated frogs’ eggs.” Proceedings of the National Academy of Sciences 38 (1952): 455–463. However later many tried with nucleus from more mature frog cells but failed. In 1958, Gurdon (Oxford,UK), successfully cloned a frog using intact nuclei from the somatic cells (gut epitheial cells) of a tadpole and won the Nobel prize together with Yamanaka. These experiments are well documented and part of the history. Going by logic one would think, reprogramming an immature cell is easier compared to a differentiated and mature cell which has undergone extensive epigenetic rearrangements and condensation of chromosomes. It is also reported that generating iPSC or embryonic cells through SCNT from older adults is more difficult compared to infants or children. Moreover, isolation, purification of haematopoietic stem cells by FACS or Magnetic beads (involving seven markers) might have damaged these cells more compared to granulocytes which were isolated by anti-Gr-1 and scatter. The abundance and ease of isolation of granulocytes might have contributed to this observation which was interpreted by the authors as suggested by the title "Differentiated cells are more efficient than adult stem cells for cloning by somatic cell nuclear transfer"!