Genes Cut Out of Reprogrammed Cells

Lots of people (here, here, and here, etc.) are commenting on the "Proof of Concept" by Jaenisch, et. al., in this week's ScienceExpress (early online publication before print) that showed gene modification to reprogram mouse cells in order to create blood line stem cells that would achieve gene therapy - or even, a cure - for sickle cell anemia.

(BTW, these mice are called "humanized knock in mice," meaning that the genes of the have been modified so that the their bone marrow hematopoietic or blood line stem cells have genes "knocked in" to produce human cells blood cells.)

To reduce the potential risk of tumor formation due to c-Myc transgene expression (13), iPS cells were infected with an adenovirus encoding Cre-recombinase to delete the lentivirus transduced c-Myc copies. One out of 10 iPS subclones (iPS #3.3) had deleted both transduced copies of c-Myc and was used for further experimentation (Fig. 2C).

Trust me, as soon as more labs figure out how to make use of these cells, to remove or repair - or to ensure there's no - damage from the insertion of the needed genes, the push for embryos will slow down. (I think it would even faster if Thomson and the California Institute for Regenerative Medicine could find a way to capitalize on adult stem cell research.)