Methods, uses, and animals for introgression of alleles between animals, including SNPs. One embodiment involves introducing a targeted targeting endonuclease system and a HDR template into a cell with a mismatch in the binding of the targeting endonuclease and the targeted site.

Described herein is a method for producing a chimeric non-human animal expressing a human ETV2 gene comprising: a) generating an ETV2 null non-human animal cell, wherein both copies of the non-human ETV2 gene carry a mutation that prevents production of functional ETV2 protein in said non-human animal; b) creating an ETV2 null non-human blastocyst by somatic cell nuclear transfer comprising fusing a nucleus from said ETV2 null non-human animal cell of a) into an enucleated non-human oocyte and activating said oocyte to divide so as to form an ETV2 null non-human blastocyst; c) introducing human stem cells into the ETV2 null non-human blastocyst of b); and d) implanting said blastocyst from c) into a pseudopregnant surrogate non-human animal to generate a chimeric non-human animal expressing human ETV2.

Provided is gRNA specifically targeting β4GalNT2 gene. The gRNA specifically binds to the nucleotide sequence shown in any one of SEQ ID NOs. 1 and 2. Also provided are an animal model constructed using the gRNA, and an application thereof in the field of biomedicine.

The invention provides double knockout transgenic pigs (GT/CMAH-KO pigs) lacking expression of any functional αGAL and CMAH. Double knockout GT/CMAH-KO transgenic organs, tissues and cells are also provided. Methods of making and using the GT/CMAH-KO pigs and tissue are also provided.

A biological system for generating and preserving a repository of personalized, humanized transplantable cells, tissues, and organs for transplantation, wherein the biological system is biologically and metabolically active (living), the biological system comprising genetically reprogrammed proteins, cells, tissues, and/or organs in a non-human animal donor for transplantation into a human recipient, wherein the non-human animal donor is a genetically reprogrammed porcine donor for xenotransplantation of cells, tissue, and/or an organ isolated from the genetically reprogrammed porcine donor.

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.

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.

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.