And a sidelight which reflects the many inaccuracies and hype which surround this topic: the L.A. Times story mentioned that no replications of the Dolly experiment had previously succeeded, either with sheep or cows. All the other cases of so-called cloning were not based on adult cells, but relied on fetal or embryo cells. That is why this result with mice is so important. The Dolly people are now breathing a sigh of relief, taking this as confirmation of the basic principle of cloning of adult cells.
This previous lack of replication was certainly not the impression given by the press in all the coverage of "cloning" since Dolly.
: Their research marks the first time anyone has demonstrably duplicated the
: controversial cloning experiment that produced Dolly--by reproducing an
: animal from the nucleus of a mature cell taken from an adult. Until now,
: except for Dolly, researchers have succeeded only in cloning cattle
: and other livestock from cells taken from embryos or fetuses, not from
: adults. In part because no one had been able to repeat the experiment,
: several prominent biologists had argued that the famous sheep was not
: a biological breakthrough but a laboratory error.