장건 교수

Many genome-edited animals have been produced using clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 technology to edit specific genes. However, there are few guidelines for the application of this technique to cattle. The goal of this study was to produce trait-improved cattle using the genome-editing technology CRISPR-Cas9. Myostatin (MSTN) was selected as a target locus, and synthetic mRNA of sgRNA and Cas9 were microinjected into fertilized bovine embryos in vitro. As

The production of transgenic farm animals (e.g., cattle) via genome engineering for the gain or loss of gene functions is an important undertaking. In the initial stages of genome engineering, DNA micro-injection into one-cell stage embryos (zygotes) followed by embryo transfer into a recipient was performed because of the ease of the procedure. However, as this approach resulted in severe mosaicism and has a low efficiency, it is not typically employed in the cattle as priority, unlike in mice.

Here, we efficiently generated transgenic cattle using two transposon systems (Sleeping Beauty and Piggybac) and their genomes were analyzed by next-generation sequencing (NGS). Blastocysts derived from microinjection of DNA transposons were selected and transferred into recipient cows. Nine transgenic cattle have been generated and grown-up to date without any health issues except two. Some of them expressed strong fluorescence and the transgene in the oocytes from a superovulating one were det

The purpose of this study was to evaluate the effect of glycosaminoglycans (GAGs) added to the culture medium on the developmental competence of bovine embryos derived from in vitro fertilization (IVF) and from somatic cell nuclear transfer (SCNT). In vitro-matured oocytes were either inseminated with 1 x 10(6) spermatozoa mL(-1) or enucleated and reconstructed with bovine adult ear fibroblasts by SCNT. The embryos were then cultured in modified synthetic oviduct fluid (mSOF) containing 8 mg mL(

Overall, these data demonstrate that transposon-mediated transgenesis can be applied to cattle without being detrimental to their long-term genomic stability or general health. We further suggest that this technology may be usefully applied in other fields, such as the generation of transgenic animal models.

A recent emerging technology, somatic cell nuclear transfer (SCNT), has been considered for conserving threatened or endangered species. Sapsaree is a native breed in Korea and has been designated as a Natural Monument. The aim of this study was to produce a Sapsaree by SCNT for breed conservation. Donor fibroblasts from a 9-year-old male Sapsaree were placed into the perivitelline spaces of enucleated in vivo matured oocytes and fused electrically. A total of 309 cloned embryos were transferred

This study compared the developmental competence of somatic cell nuclear transfer (SCNT) embryos reconstructed with different donor cells and analysed gene expression in the resulting embryos. Bovine fetal/adult ear fibroblasts and cumulus cells were used as donor cells and the developmental competence of the reconstructed embryos was monitored. The cell number and allocation in blastocysts were determined by differential staining. The Bax, E-cad, IF-tau, Hsp (heat shock protein) 70, Igf2r (insu

The potential of induced pluripotent stem (iPS) cells, which have self-renewal ability and can differentiate into three germ layers, led us to hypothesize that iPS cells in pigs can be useful and suitable source for producing transgenic pigs. In this study, we generated iPS-like cells using doxycycline-inducible piggyBac (PB) expression vectors encoding porcine 4 transcription factors. After transfection, transfected cells were cultured until the formation of outgrowing colonies taking least of

It is recommended that PMDS should be differentially diagnosed by ultrasonography and that orchiectomy be performed at an early age in patients suspected to have cryptorchidism to prevent the ectopic testes from becoming tumorous.