The present invention provides methods and compostions to improve the efficiency of somatic cell nuclear transfer (SCNT) and the consequent production of nuclear transfer ESC (ntESC) and transgenic cells and/or non-human animals. More specifically, the present invention relates to the discovery that trimethylation of Histone H3-Lysine 9 (H3K9me3) in reprogramming resistant regions (RRRs) in the nuclear genetic material of donor somatic cells prevents efficient somatic cell nuclear reprogramming or SCNT. The present invention provide methods and compositions to decrease H3K9me3 in methods to improve efficacy of SCNT by exogenous or overexpression of the demethylase Kdm4 family and/or inhibiting methylation of H3K9me3 by inhibiting the histone methyltransferases Suv39h1 and/or Suv39h2.

The present invention provides methods and compostions to improve the efficiency of somatic cell nuclear transfer (SCNT) and the consequent production of nuclear transfer ESC (ntESC) and transgenic cells and/or non-human animals. More specifically, the present invention relates to the discovery that trimethylation of Histone H3-Lysine 9 (H3K9me3) in reprogramming resistant regions (RRRs) in the nuclear genetic material of donor somatic cells prevents efficient somatic cell nuclear reprogramming or SCNT. The present invention provide methods and compositions to decrease H3K9me3 in methods to improve efficacy of SCNT by exogenous or overexpression of the demethylase Kdm4 family and/or inhibiting methylation of H3K9me3 by inhibiting the histone methyltransferases Suv39h1 and/or Suv39h2.

Provided is a double-gene knockout vector system, a method for preparing porcine fibroblasts with both CD163 gene and CD13 gene being knocked-out, prepared porcine fibroblasts, and a method for preparing a gene-edited pig with both CD163 gene and CD13 gene being knocked-out. The vector system of the present disclosure comprises a CD163 gene knockout vector and a CD13 gene knockout vector. The CD163 gene knockout vector comprises a gene editing vector backbone and a DNA fragment ligated to the gene editing vector backbone, with a nucleotide sequence of the DNA fragment being shown in any one of SEQ ID NOs: 1-3. The CD13 gene knockout vector comprises a gene editing vector backbone and a DNA fragment ligated to the gene editing vector backbone, a nucleotide sequence of the DNA fragment being shown in any one of SEQ ID NOs: 4-6.

The present invention relates to a transgenic pig comprising a mutated IAPP gene and displaying a phenotype associated with diabetes. The invention also relates to a transgenic blastocyst, embryo, fetus, donor cell and/or cell nucleusderived from said transgenic pig. The invention further relates to use of the transgenic pig as a model system for studying therapy, treatment and/or prevention of diabetes.

Methods of producing human stem cells are disclosed for parthenogenetically activating human oocytes by manipulation of O.sub.2 tension, including manipulation of Ca.sup.2+ under high O.sub.2 tension and contacting oocytes with serine threonine kinase inhibitors under low O.sub.2 tension, isolating inner cell masses (ICMs) from the activated oocytes, and culturing the cells of the isolated ICMs under high O.sub.2 tension. Moreover, methods are described for the production of stems cells from activated oocytes in the absence of non-human animal products, including the use of human feeder cells/products for culturing ICM/stem cells. Stem cells produced by the disclosed methods are also described.

Provided are cells, tissues, organs, and/or animals having one or more modified genes for enhanced xenograft survival and/or tolerance. And methods of producing and using the cells, tissues, organs, and/or animals.

Disease model pigs produced by nuclear transplantation, disease model pigs exhibiting stable phenotypes and production methods thereof are provided. Chimeric pigs for producing disease model pigs exhibiting stable phenotypes, genital glands thereof, and germ cells thereof are also provided. A method for producing a genetically modified disease model pig, includes: (a) transplanting a nucleus of a genetically modified cell into cytoplasm of an egg; (b) developing an obtained clonal embryo in a womb of a female pig to obtain an offspring; and mating the obtained offspring or having the offspring undergo sexual reproduction to further obtain the genetically modified offspring as a disease model pig.

There are provided to a Rag-2 (Recombination activating gene 2) gene targeting vector, a method for producing SCID-like miniature pigs introduced with the vector, and a use thereof.

The present disclosure relates methods and compositions useful for prevention of porcine reproductive and respiratory syndrome virus (PRRSv) in animals, including animals of the species Sus scrofa. The present teachings relate to swine wherein at least one allele of a CD163 gene has been inactivated, and to specific methods and nucleic acid sequences used in gene editing to inactivate the CD163 gene. Swine wherein both alleles of the CD163 gene are inactivated are resistant to porcine reproductive and respiratory syndrome virus (PRRSv). Elite lines comprising homozygous CD163 edited genes retain their superior properties.

An object of the present invention is to provide a humanized mouse in which human hematopoietic stem cells can be engrafted for a long term. The present invention relates to a humanized rodent having human neutrophils circulating in a periphery, obtained by transplanting a human hematopoietic stem cell into a human G-CSF gene knock-in rodent, which is an immunodeficient rodent deficient in a G-CSF receptor function by knock-in of a human G-CSF gene at a G-CSF receptor locus, wherein a human G-CSF is expressed and a rodent G-CSF receptor is not expressed.