The invention provides methods for reprogramming somatic cells to generate multipotent or pluripotent cells. Such methods are useful for a variety of purposes, including treating or preventing a medical condition in an individual. The invention further provides methods for identifying an agent that reprograms somatic cells to a less differentiated state.

Described here are methods, compositions, and systems for generating transgenic islet cells suitable for xenotransplantation.

Manufacturing processes are described for biological replication of undifferentiated plant and animal cells and tissue in a weightless condition, including those systems used in current stem cell research and development and use of undifferentiated parenchyma in plants. Additionally, methods for adapting plants and animals to survive outside their native environments are described. In particular, undifferentiated cells from plants or animals are replicated under weightless conditions in which cell replication or proliferation is accelerated and sustained. Under such conditions, the undifferentiated cells can be “forced” to express sets of genes useful for survival in particular environmental conditions. In this manner, cells surviving prolonged exposure to specific environmental conditions can be selected for and cultivated to produce an organism adapted to that particular environment in an accelerated manner. Methods of identifying specific genes associated with adaptation of a plant or animal to a specific environment are also described.

Provided are compositions for simultaneously modifying amino acids of site 736 and site 738 of pAPN gene and application thereof. An sgRNA set specifically recognizing porcine pAPN gene can recognize sequences near amino acids of site 736 and site 738 of pAPN gene, and has strong specificity. On this basis, in combination with a composition consisting of a cleavage protein and a double-stranded donor sequence, simultaneous modification of amino acids of site 736 and site 738 of the pAPN gene can be realized. Under editing of the composition, the amino acids of site 736 and site 738 of the pAPN gene are modified precisely and effectively, which can prevent normal expression of other amino acids of the pAPN gene from being damaged or changed. Therefore, it can resist TGEV infection, and also can retain the physiological activity function of the pAPN protein to the maximum extent.

The invention provides methods for reprogramming somatic cells to generate multipotent or pluripotent cells. Such methods are useful for a variety of purposes, including treating or preventing a medical condition in an individual. The invention further provides methods for identifying an agent that reprograms somatic cells to a less differentiated state.

An organ for transplantation having a kidney, a ureter, and a urinary bladder and an organ structure in which a first ureter, a first urinary bladder, a second ureter and a second urinary bladder are sequentially connected to a kidney can produce urine and excrete the produced urine, and thus is useful for transplantation.

The present invention provides novel methods for improving the efficiency of artificial activation of unfertilized mammalian oocytes by reducing the intracellular concentration of Zn.sup.2+ in the oocyte. The methods of the invention may additionally comprise a preceding step of increasing the intracellular concentration of Ca.sup.2+ in the oocyte prior to reduction of the intracellular Zn.sup.2+ concentration. The invention further provides unfertilized oocytes activated by the disclosed methods and viable mammalian animals produced from unfertilized oocytes activated by the disclosed methods.

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 is transgenic chickens obtained from long-term cultures of avian PGCs and techniques to produce and transgenic birds derived from prolonged PGC cultures. In some embodiments, these PGCs can be transfected with genetic constructs to modify the DNA of the PGC, specifically to introduce a transgene encoding an exogenous protein. When combined with a host avian embryo by known procedures, those modified PGCs are transmitted through the germline to yield transgenic offspring. This invention includes compositions comprising long-term cultures of PGCs and offspring derived from them that are genetically modified. The genetic modifications introduced into PGCs to achieve the gene inactivation may also include, but are not restricted to, random integrations of transgenes into the genome, transgenes inserted into the promoter region of genes, transgenes inserted into repetitive elements in the genome, site specific changes to the genome that are introduced using integrase, site specific changes to the genome introduced by homologous recombination, and conditional mutations introduced into the genome by excising DNA that is flanked by lox sites or other sequences that are substrates for site specific recombination.