Resurrection of an @entity22388 gene-targeted miniature XXXX by recloning using postmortem ear skin fibroblasts.

@entity1707 @entity22388 @entity649 @entity1358 @entity299
Animals with a targeted disruption of genes can be produced by @entity1358 ( @entity1358 ). However, difficulties in clonal selection of somatic cells with a targeted mutation often result in heterogeneous nuclear donor cells, including gene-targeted and non-targeted cells, and impose a risk of producing undesired wildtype cloned animals after @entity1358 . In addition, the efficiency of cloning by @entity1358 has remained extremely low. Most cloned embryos die in utero, and the few that develop to term show a high incidence of postnatal death and abnormalities. In the present study, resurrection of an @entity22388 ( @entity22388 ) gene-targeted miniature @entity1707 by recloning using postmortem ear skin fibroblasts was attempted. Three cloned piglets were produced from the first round of @entity1358 , including one stillborn and two who died immediately after birth due to @entity649 and @entity299 . Among the three piglets, two were confirmed to be @entity22388 gene-targeted. Fibroblasts derived from postmortem ear skin biopsies were used as nuclear donor cells for the second round of @entity1358 , and a piglet was produced. As expected, PCR and Southern analyses confirmed that the piglet produced from recloning was @entity22388 gene-targeted. Currently, the piglet is fourteen months of age, and no overt health problems have been observed. Results from the present study demonstrate that loss of an invaluable animal, such as a gene-targeted miniature @entity1707 , may be rescued by recloning, with assurance of the desired genetic modification.
