GZTC is only affected to the extent that cloning their goats may not work well. OTOH, cloned goats may still produce the desired drug in their milk even if they aren't otherwise perfect. I doubt BTRN has got any stem cell play in its price at all - it's all been very low profile indeed.
I don't understand the issues well enough to comment on the effect on GERN, STEM etc.
Here's the Science abstract that seemed to set off the discussion:
Epigenetic Instability in ES Cells and Cloned Mice
David Humpherys,12* Kevin Eggan,12* Hidenori Akutsu,3* Konrad Hochedlinger,1 William M. Rideout III,1 Detlev Biniszkiewicz,1 Ryuzo Yanagimachi,3 Rudolf Jaenisch12
Cloning by nuclear transfer (NT) is an inefficient process in which most clones die before birth and survivors often display growth abnormalities. In an effort to correlate gene expression with survival and fetal overgrowth, we have examined imprinted gene expression in both mice cloned by nuclear transfer and in the embryonic stem (ES) cell donor populations from which they were derived. The epigenetic state of the ES cell genome was found to be extremely unstable. Similarly, variation in imprinted gene expression was observed in most cloned mice, even in those derived from ES cells of the same subclone. Many of the animals survived to adulthood despite widespread gene dysregulation, indicating that mammalian development may be rather tolerant to epigenetic aberrations of the genome. These data imply that even apparently normal cloned animals may have subtle abnormalities in gene expression.
1 Whitehead Institute for Biomedical Research,
2 Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge MA 02142, USA.
3 Department of Anatomy and Reproductive Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI 96822, USA.
* These authors contributed equally to this work.
Peter |
