Cloning tools

While numerous groups have generated cloned mice using embryonic stem cells as nuclear donors, few have accomplished the same feat with differentiated somatic cells. Two groups reported last week the production of cloned mice from terminally differentiated somatic cells, and the results spotlight the variability in results derived from slightly different methods.

The results thus underscore the hurdles that remain in cloning technology. Nevertheless, one of the mouse lines provides a new vehicle to study the mechanisms of gene rearrangement and antibody diversity in B lymphocytes...