Cloning mammals by means of somatic cell nuclear transfer (SCNT) is highly inefficient because of erroneous reprogramming of the donor genome. Reprogramming errors appear to arise randomly, but the nature of nonrandom, SCNT-specific errors remains elusive. We found that Xist, a noncoding RNA that inactivates one of the two X chromosomes in females, was ectopically expressed from the active X (X...

OBJECTIVE To create genetically modified goat as a biopharming source of recombinant human lacotoferrin (hLF) with transcription activator-like effector nucleases. METHODS TALENs and targeting vector were transferred into cultured fibroblasts to insert hLF cDNA in the goat beta-lactoglobulin (BLG) locus with homology-directed repair. The gene targeted efficiency was checked using sequencing a...

In mouse somatic cell nuclear transfer (SCNT), polyvinylpyrrolidone (PVP) is typically included in the nuclear donor injection medium. However, the cytotoxicity of PVP, which is injected into the cytoplasm of oocytes, has recently become a cause of concern. In the present study, we determined whether bovine serum albumin deionized with an ion-exchange resin treatment (d-BSA) was applicable to t...

This document presents arguments that conclude that it is unethical to use somatic cell nuclear transfer (SCNT) for infertility treatment due to concerns about safety; the unknown impact of SCNT on children, families, and society; and the availability of other ethically acceptable means of assisted reproduction. This document replaces the ASRM Ethics Committee report titled, "Human somatic cell...

This workshop focused on describing clinical problems identified in the placentae of cloned animals and some of the potential biological mechanisms by which these anomalies arise. It was shown that placental anomalies related to somatic cell nuclear transfer (SCNT) in cattle often can be detected by ultrasonography early in gestation, enabling preventive clinical intervention. On the mechanisti...

Somatic cell nuclear transfer (SCNT), commonly referred to as cloning, results in the generation of offspring that, except for mitochondrial DNA, are genetically identical to the nuclear donor. We previously used a genetically modified bovine cell line as the donor for SCNT and obtained a calf, named Daisy, that was born without a tail. To determine whether the missing tail was a result of the ...

The developmental competence of in vitro cultured (IVC) embryos is markedly lower than that of their in vivo counterparts, suggesting the need for optimization of IVC protocols. Embryo culture medium is routinely replaced three days after initial culture in bovine, however, whether this protocol is superior to continuous nonrenewal culture method under current conditions remains unclear. Using ...

Cloning by somatic cell nuclear transfer (SCNT) circumvents processes that normally function during gametogenesis to prepare the gamete genomes to support development of new progeny following fertilization. One such process is enhanced maintenance of genetic integrity in germ cells, such that germ cells typically carry fewer spontaneously acquired mutations than somatic cells in the same indivi...

Buffalo are characteristic livestock of the Guangxi Zhuang Autonomous Region of China, but their low reproductive capacity necessitates the use of somatic cell nuclear transfer (SCNT). We investigated the effects of RG108 on DNA methylation in buffalo adult fibroblasts, and on subsequent SCNT embryo development. RG108 treatment (0, 5, 10, 20, and 100 mM) had no effect on cell morphology, viabil...