These repercussions seem far more momentous than are the modest scientific achievements to which ACT researchers lay claim. Indeed, they reported only very limited success in efforts to clone human embryos, saying that few cloned embryos among their experimental materials even reached the very early six-cell stage before ceasing to divide—falling short in terms of sought-after longevity as well as numbers of cells needed to form blastocysts, from which pluripotent stem cells eventually might be obtained. Nonetheless, the experiments indicate that nuclei from human somatic cells appear to “reprogram” egg cells, an essential early step toward cloning for either therapeutic or reproductive purposes (J. Regenerative Med., 2, 25, 2001). ACT chief executive Michael West says these recent disclosures are intended to keep this area of research “transparent”.
Meanwhile, ACT researchers and their collaborators claim more success in applying similar cloning procedures to other species (Science, 294, 1893, 2001). For example, they report a 14% rate of success in forming macaque blastocysts from harvested egg cells through parthenogenesis, a process for activating development of such cells without fertilizing them with sperm. ACT and its subsidiary Cyagra (Worcester, MA) also report an 80% success rate in producing viable cattle through cloning, with nuclei from proliferating cattle skin cells serving as a source of donor genetic materials. “All of the data collected reinforce the view that these animals were clinically and phenotypically normal,” says Robert Lanza, who is medical and scientific vice president for ACT.
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