Somatic cell nuclear transfer (SCNT) is a cost-effective technique for producing transgenic pigs. However, abnormalities in the cloned pigs might prevent use these animals for clinical applications or disease modeling. In the present study, we generated several cloned pigs. One of the pigs was found to have intrapancreatic ectopic splenic tissue during histopathology analysis although this animal was grossly normal and genetically identical to the other cloned pigs. Ectopic splenic tissue in the pancreas is very rare, especially in animals. To the best of our knowledge, this is the first such report for cloned pigs.
Animals ; Animals, Genetically Modified ; Choristoma/pathology/*veterinary ; Cloning, Organism ; Nuclear Transfer Techniques/*veterinary ; *Pancreas ; Splenic Diseases/pathology/*veterinary ; Swine ; Swine Diseases/*pathology ; Swine, Miniature

The objective of the present study was to investigate the effects of three different culture media on the development of canine somatic cell nuclear transfer (SCNT) embryos. Canine cloned embryos were cultured in modified synthetic oviductal fluid (mSOF), porcine zygote medium-3 (PZM-3), or G1/G2 sequential media. Our results showed that the G1/G2 media yielded significantly higher morula and blastocyst development in canine SCNT embryos (26.1% and 7.8%, respectively) compared to PZM-3 (8.5% and 0%) or mSOF (2.3% and 0%) media. In conclusion, this study suggests that blastocysts can be produced more efficiently using G1/G2 media to culture canine SCNT embryos.
Animals ; Blastocyst/cytology ; Cloning, Organism/*veterinary ; Culture Media/metabolism ; Dogs/*embryology ; Embryo Culture Techniques/*veterinary ; *Embryonic Development ; Nuclear Transfer Techniques/*veterinary

Various somatic cell nuclear transfer (SCNT) techniques for mammalian species have been developed to adjust species-specific procedures to oocyte-associated differences among species. Species-specific SCNT protocols may result in different expression levels of developmentally important genes that may affect embryonic development and pregnancy. In the present study, porcine oocytes were treated with demecolcine that facilitated enucleation with protruding genetic material. Enucleation and donor cell injection were performed either simultaneously with a single pipette (simplified one-step SCNT; SONT) or separately with different pipettes (conventional two-step SCNT; CTNT) as the control procedure. After blastocysts from both groups were cultured in vitro, the expression levels of developmentally important genes (OCT4, NANOG, EOMES, CDX2, GLUT-1, PolyA, and HSP70) were analyzed by real-time quantitative polymerase chain reaction. Both the developmental rate according to blastocyst stage as well as the expression levels CDX2, EOMES, and HSP70 were elevated with SONT compared to CTNT. The genes with elevated expression are known to influence trophectoderm formation and heat stress-induced arrest. These results showed that our SONT technique improved the development of SCNT porcine embryos, and increased the expression of genes that are important for placental formation and stress-induced arrest.
Animals ; Biological Markers/metabolism ; Cloning, Organism ; Embryo, Mammalian/metabolism ; Female ; *Gene Expression Regulation, Developmental ; Nuclear Transfer Techniques/instrumentation/*veterinary ; Oocytes/metabolism ; Pregnancy ; Real-Time Polymerase Chain Reaction ; Swine/*embryology/*genetics

In producing transgenic livestock, selectable marker genes (SMGs) are usually used to screen transgenic cells from numerous normal cells. That results in SMGs integrating into the genome and transmitting to offspring. In fact, SMGs could dramatically affect gene regulation at integration sites and also make the safety evaluation of transgenic animals complicated. In order to determine the deletion time and methods in the process of producing transgenic goats, the feasibility of deleting SMGs was explored by Cre/LoxP before or after somatic cell cloning. In addition, we compared the efficiency of protein transduction with plasmids co-transduction. We could delete 43.9% SMGs after screening out the transgenic cell clones, but these cells could not be applied to somatic cells cloning because of serious aging after two gene modifications. The SMG-free cells suitable for nuclear transfer were accessible by using the cells of transgenic goats, but this approach was more time consuming. Finally, we found that the Cre plasmid could delete SMGs with an efficiency of 7.81%, but about 30% in SMG-free cells had sequences of Cre plasmid. Compared with Cre plasmid, the integration of new exogenous gene could be avoided by TAT-CRE protein transduction, and the deletion rate of TAT-CRE transduction was between 43.9 and 72.8%. Therefore, TAT-Cre transduction could be an effective method for deleting selectable marker genes.
Animals ; Animals, Genetically Modified ; genetics ; Cloning, Organism ; veterinary ; Gene Knockout Techniques ; Gene Targeting ; methods ; Genes, Reporter ; Genetic Engineering ; Genetic Vectors ; genetics ; Goats ; genetics ; Integrases ; chemistry ; metabolism ; Recombination, Genetic ; Transgenes ; genetics

We compared the efficiency of cloning goat using human lactoferrin (hLF) with genetically modified donor cells marked by single (Neo(r)) or double (Neo(r)/GFP) markers. Single marker expression vector (pBLC14) or dual markers expression vector (pAPLM) was delivered to goat fetal fibroblasts (GFF), and then the transgenic GFF was used as donor cells to produce transgenic goats. Respectively, 58.8% (20/34) and 86.7% (26/30) resistant cell lines confirmed the transgenic integration by PCR. Moreover, pAPLM cells lines were subcultured with several passages, only 20% (6/30) cell lines was observed fluorescence from each cell during the cell passage. Somatic cell nuclear transfer using the donor cells harbouring pBLC14 or pAPLM construct, resulting in a total of 806 reconstructed embryos, a pregnancy rate at 35 d (53.8%, 39.1%) and 60 d (26.9%, 21.7%), and an offspring birth rate (1.9%, 1.4%) with 5 and 7 newborn cloned goats, respectively. Transgene was confirmed by PCR and southern-blot in all cloned offspring. There were no significant differences at the reconstructed embryo fusion rates, pregnancy rates and the birth rate (P > 0.05) between single and double markers groups. The Neo(r)/GFP double markers could improve the reliability for accurately and efficiently selecting the genetically modified donor cells. No adverse effect was observed on the efficiency of transgenic goat production by SCNT using somatic cells transfected with double (Neo(r)/GFP) markers vector.
Animals ; Animals, Genetically Modified ; genetics ; Cloning, Molecular ; Cloning, Organism ; methods ; veterinary ; Fetus ; Fibroblasts ; cytology ; Genetic Markers ; Goats ; embryology ; genetics ; Green Fluorescent Proteins ; genetics ; Humans ; Lactoferrin ; biosynthesis ; genetics ; Neomycin ; Nuclear Transfer Techniques ; veterinary ; Recombinant Proteins ; biosynthesis ; genetics ; Transfection ; veterinary

Recently, we reported the three wolves cloning with normal karyotype from somatic cells of endangered male gray wolves (Canis lupus), but one wolf had female external genitalia. In this study, we conducted further clinical, histological, and genetic analyses. This cloned wolf had a normal uterus but developed ovotestis. Through molecular analysis of the SRY gene, a mutation in the coding sequence of SRY gene could be excluded as a cause of intersexuality. This is the first report of a cloned wolf with a 78, XY ovotesticular disorder affecting sexual development characterized by bilateral ovotestes.
Animals ; Cloning, Organism/*veterinary ; Female ; Karyotyping ; Mutation ; Nuclear Transfer Techniques/*veterinary ; Ovotesticular Disorders of Sex Development/pathology/*veterinary ; *Wolves

Recently, the world's first transgenic dogs were produced by somatic cell nuclear transfer. However, cellular senescence is a major limiting factor for producing more advanced transgenic dogs. To overcome this obstacle, we rejuvenated transgenic cells using a re-cloning technique. Fibroblasts from post-mortem red fluorescent protein (RFP) dog were reconstructed with in vivo matured oocytes and transferred into 10 surrogate dogs. One puppy was produced and confirmed as a re-cloned dog. Although the puppy was lost during birth, we successfully established a rejuvenated fibroblast cell line from this animal. The cell line was found to stably express RFP and is ready for additional genetic modification.
Animals ; Animals, Genetically Modified ; Cloning, Organism/methods/*veterinary ; Dogs/*genetics ; Female ; Gastrointestinal Tract/metabolism ; Gene Expression Regulation ; Kidney/metabolism ; Liver/metabolism ; Luminescent Proteins/*genetics/metabolism ; Lung/metabolism ; Male ; Myocardium/metabolism ; Nuclear Transfer Techniques/veterinary ; Spleen/metabolism ; Trachea/metabolism

Somatic cell nuclear transfer (SCNT) is considered to be a critical tool for propagating valuable animals. To determine the productivity calves resulting from embryos derived with different culture media, enucleated oocytes matured in vitro were reconstructed with fetal fibroblasts, fused, and activated. The cloned embryos were cultured in modified synthetic oviduct fluid (mSOF) or a chemically defined medium (CDM) and developmental competence was monitored. After 7 days of culturing, the blastocysts were transferred into the uterine horn of estrus-synchronized recipients. SCNT embryos that were cultured in mSOF or CDM developed to the blastocysts stages at similar rates (26.6% vs. 22.5%, respectively). A total of 67 preimplantational stage embryos were transferred into 34 recipients and six cloned calves were born by caesarean section, or assisted or natural delivery. Survival of transferred blastocysts to live cloned calves in the mSOF and the CDM was 18.5% (to recipients), 9.6% (to blastocysts) and 42.9% (to recipients), 20.0% (to blastocysts), respectively. DNA analysis showed that all cloned calves were genetically identical to the donor cells. These results demonstrate that SCNT embryos cultured in CDM showed higher viability as judged by survival of the calves that came to term compared to blastocysts derived from mSOF cultures.
Animals ; Blastocyst/physiology ; *Cattle ; Cloning, Organism/methods/*veterinary ; Culture Media/chemistry ; Embryo Culture Techniques ; Embryo Transfer ; Embryonic Development ; Female ; Fertilization in Vitro/*veterinary ; Nuclear Transfer Techniques/*veterinary ; Pregnancy

The aberrant epigenetic reprogramme is an important cause for abnormal development of nuclear transfer embryos. The objective of this study was to investigate the CpG island methylation profiles and relative expression levels of H19 gene in different tissues of cloned goat fetus. We detected liver, placenta, kidney, lung and heart in the dead cloned goat fetus and the age-matched normal goat fetus (control) by using bisulfite sequencing and real time PCR. Results indicated that methylation levels of the fifth CpG island of H19 gene in dead cloned goat fetus was significant high compared with that in the control in placenta (70% vs 49.41%, P < 0.05), and relative expression levels of H19 gene was significant low compared with that in the control (883.3 vs 1 264.5, P < 0.05). Reversely, the methylation levels was significant low compared with that in the control in lung (63.53% vs 88.24%, P < 0.05), and relative expression levels was significant high compared with that in the control (1 003.4 vs 515.5, P < 0.05). The differences of others groups were insignificant (P > 0.05). Results showed the abnormal DNA methylation proflies of H19 gene occurred in some tissues of cloned goat fetus, which affected normal expression levels of H19 gene, indicating that aberrant DNA methylation reprogramme may be one of the important factors for the death of cloned animals.
Animals ; Cloning, Organism ; veterinary ; CpG Islands ; DNA Methylation ; Epigenesis, Genetic ; Female ; Fetus ; metabolism ; Genomic Imprinting ; Goats ; Kidney ; embryology ; metabolism ; Liver ; embryology ; metabolism ; Lung ; embryology ; metabolism ; Nuclear Transfer Techniques ; RNA, Long Noncoding ; RNA, Untranslated ; genetics ; metabolism

In order to enhance the efficiency of sheep somatic cell nuclear transfer, we used a chemically assisted enucleation with colchicine to study the effects of the concentration of colchicine, the incubation time of oocytes in colchicine and the maturation time of oocytes on the enucleation rates and the development of reconstructed embryos. The results showed that 1) there were no significant differences in the rates of cytoplast protrusion and enucleation between oocytes that were incubated in colchicine (0.4 microg/mL) for 0.5 h and oocytes that were incubated in colchicine (0.4 microg/mL) for 1 h, and the rate of cytoplast protrusion can be 85.4% while the rate of cytoplast enucleation is 100%. 2) There was no significant difference in oocyte enucleation between oocytes treated with medium containing 0.2 microg/mL colchicine for 0.5 h and oocytes treated with medium containing 0.4 microg/mL colchicine for 0.5 h. 3) A maturation time of 18-23 h did not affect the rates of cytoplast protrusion and enucleation by chemically assisted enucleation, whereas the rate of enucleation of oocytes by blind enucleation was found to decrease with a prolonged incubation time. 4) The development rates of reconstructed embryos could not be influenced by these two enucleation methods, increased from oocytes matured for 21-23 h. These results demonstrate that sheep oocytes can be enucleated fast and effectively by optimized colcholine chemically assisted enucleation, which can enhance the enucleation rate of sheep oocytes and the early development of reconstructed embryos in vitro.
Animals ; Cloning, Organism ; methods ; Colchicine ; pharmacology ; Embryo, Mammalian ; embryology ; Female ; Nuclear Transfer Techniques ; veterinary ; Oocytes ; cytology ; drug effects ; Sheep