Cloning for conservation

URL: http://www.nature.com/cgi-taf/DynaPage.taf?file=/nbt/journal/v18/n11/full/nbt1100_1129a.html

Nature Biotech, November 2000 Volume 18 Number 11 p 1129 

Andrew Marshall

                  The creation of a functional chimeric fetus via nuclear transfer

                  between two different species has been demonstrated for the

                  first time, with significant implications for wildlife conservation

                  (Cloning 2, 79–90, 2000). Previous in vitro studies had shown

                  the feasibility of nuclear transfer between sheep, pigs,

                  monkeys, or rats and enucleated bovine oocytes. In the new

                  report, a collaboration of academic and industrial researchers

                  has taken the first steps in cloning an endangered wild Asian ox

                  (or gaur; Bos gaurus) by electrofusing fibroblasts from the

                  animal's skin with enucleated bovine oocytes. Twelve percent of

                  the reconstructed oocytes developed into blastocysts, and 18%

                  of these developed to the fetal stage when transferred to

                  pseudopregnant cows. Inspection of fetuses removed at days

                  46 and 54 (twins), and a fetus aborted at day 202, revealed no

                  evidence of gross external abnormalities. Microsatellite and

                  cytogenetic analysis also confirmed that the genome of the

                  cloned animals was gaurus in origin, whereas the mitochondrial

                  DNA was bovine. According to lead author Robert Lanza of

                  Advanced Cell Technology (Worcester, MA), one pregnancy is

                  still ongoing and is due for delivery by cesarean in late

                  November. "We are also working with the Spanish government

                  to use this technology in goats to clone an extinct bucardo

                  mountain goat from preserved cells," he says.