Abstract
The compounds 6-dimethylaminopurine and cycloheximide promote the successful production of cloned mammals and have been used in the development of embryos produced by somatic cell nuclear transfer. This study investigated the effects of 6-dimethylaminopurine and cycloheximide in vitro, using the thiazolyl blue tetrazolium bromide colorimetric assay to assess cytotoxicity, the trypan blue exclusion assay to assess cell viability, the comet assay to assess genotoxicity, and the micronucleus test with cytokinesis block to test mutagenicity. In addition, the comet assay and the micronucleus test were also performed on peripheral blood cells of 54 male Swiss mice, 35 g each, to assess the effects of the compounds in vivo. The results indicated that both 6-dimethylaminopurine and cycloheximide, at the concentrations and doses tested, were cytotoxic in vitro and genotoxic and mutagenic in vitro and in vivo, altered the nuclear division index in vitro, but did not diminish cell viability in vitro. Considering that alterations in DNA play important roles in mutagenesis, carcinogenesis, and morphofunctional teratogenesis and reduce embryonic viability, this study indicated that 6-dimethylaminopurine and cycloheximide utilized in the process of mammalian cloning may be responsible for the low embryo viability commonly seen in nuclear transfer after implantation in utero.
Highlights
The somatic cell nuclear transfer (SCNT) technique is being used to clone a variety of animal species, including cattle, sheep, mice, rats, goats, pigs, cats, rabbits, and horses
The concentrations utilized in the genotoxicity and mutagenicity assays were determined by the colorimetric thiazolyl blue tetrazolium bromide (MTT) assay (CAS No 298-93-1, Sigma), which was used to determine cytotoxicity. 6-DMAP was tested at 13 concentrations between 0.014 and 60.8 mg/mL, and CHX was tested at 13 concentrations of 1.25 to 5120610–3 mg/mL in culture medium
The results of this study demonstrate that oocyteactivation agents 6-DMAP, a protein serine/threonine kinase inhibitor, and CHX, a protein synthesis inhibitor, have different effects on the induction of genotoxic and mutagenic damage in HepG2 cells and mice
Summary
The somatic cell nuclear transfer (SCNT) technique is being used to clone a variety of animal species, including cattle, sheep, mice, rats, goats, pigs, cats, rabbits, and horses. As the efficiency of SCNT improves, the technique offers more applications in agriculture, biomedical science, and endangered species preservation. Animal cloning by SCNT has the potential to improve the productivity of enormously valuable livestock and may eventually prove to be a more economical venture than current breeding methods [1,2]. SCNT may provide the ability to produce both embryonic stem cells for therapeutic use and transgenic animals that synthesize large quantities of human proteins for use in medicine [3,4]. SCNT can help in understanding gene expression and nuclear-cytoplasmic contributions to cellular function and their respective roles in Received June 24, 2013.
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call