Production of transgenic cashmere goat embryos expressing red fluorescent protein and containing IGF1 hair-follicle-cell specific expression cassette by somatic cell nuclear transfer.
ABSTRACT In the present study, cashmere goat fetal fibroblasts were transfected with pCDsR-KI, a hair-follicle-cell specific expression vector for insulin-like growth factor 1 (IGF1) that contains two markers for selection (red fluorescent protein gene and neomycin resistant gene). The transgenic fibroblasts cell lines were obtained after G418 selection. Prior to the somatic cell nuclear transfer (SCNT), the maturation rate of caprine cumulus oocytes complexes (COCs) was optimized to an in vitro maturation time of 18 h. Parthenogenetic ooctyes were used as a model to investigate the effect of two activation methods, one with calcium ionophore IA23187 plus 6-DMAP and the other with ethanol plus 6-DMAP. The cleavage rates after 48 h were respectively 88.7% and 86.4%, with no significant difference (P>0.05). There was no significant difference between the cleavage rate and the blastocyst rate in two different media (SO-Faa and CR1aa; 86.3% vs 83.9%, P>0.05 and 23.1% vs 17.2%, P>0.05). The fusion rate of a 190 V/mm group (62.4%) was significantly higher than 130 V/mm (32.8%) and 200 V/mm (42.9%), groups (P>0.05). After transgenic somatic cell nuclear transfer (TSCNT) manipulation, 203 reconstructed embryos were obtained in which the cleavage rate after in vitro development (IVD) for 48 h was 79.3% (161/203). The blastocyst rate after IVD for 7 to 9 d was 15.3% (31/203). There were 17 embryos out of 31 strongly expressing red fluorescence. Two of the red fluorescent blastocysts were randomly selected to identify transgene by polymerase chain reaction. Both were positive. These results showed that: (i) RFP and Neo ( r ) genes were correctly expressed indicating that transgenic somatic cell lines and positive transgenic embryos were obtained; (ii) one more selection at the blastocyst stage was necessary although the donor cells were transgenic positive, because only partially transgenic embryos expressing red fluorescence were obtained; and (iii) through TSCNT manipulation and optimization, transgenic cashmere goat embryos expressing red fluorescence and containing an IGF1 expression cassette were obtained, which was sufficient for production of transgenic cashmere goats.
- SourceAvailable from: August Rieke[show abstract] [hide abstract]
ABSTRACT: The presence of galactose alpha-1,3-galactose residues on the surface of pig cells is a major obstacle to successful xenotransplantation. Here, we report the production of four live pigs in which one allele of the alpha-1,3-galactosyltransferase locus has been knocked out. These pigs were produced by nuclear transfer technology; clonal fetal fibroblast cell lines were used as nuclear donors for embryos reconstructed with enucleated pig oocytes.Science 03/2002; 295(5557):1089-92. · 31.20 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: Fertilization of mammalian eggs is followed by successive cell divisions and progressive differentiation, first into the early embryo and subsequently into all of the cell types that make up the adult animal. Transfer of a single nucleus at a specific stage of development, to an enucleated unfertilized egg, provided an opportunity to investigate whether cellular differentiation to that stage involved irreversible genetic modification. The first offspring to develop from a differentiated cell were born after nuclear transfer from an embryo-derived cell line that had been induced to become quiescent. Using the same procedure, we now report the birth of live lambs from three new cell populations established from adult mammary gland, fetus and embryo. The fact that a lamb was derived from an adult cell confirms that differentiation of that cell did not involve the irreversible modification of genetic material required for development to term. The birth of lambs from differentiated fetal and adult cells also reinforces previous speculation that by inducing donor cells to become quiescent it will be possible to obtain normal development from a wide variety of differentiated cells.Nature 03/1997; 385(6619):810-3. · 38.60 Impact Factor
- J Reprod Fertil 10/1972; 30(3):493-7.