Described herein are rats with a hepatic deficiency comprising decreased function, activity, or expression of an enzyme in the tyrosine catabolic pathway (such as fumarylacetoacetate hydrolase), and methods of using the same for in vivo engraftment and expansion of heterologous hepatocytes, such as human hepatocytes, analysis of human liver disease, and analysis of xenobiotics. Also disclosed is the use of immunodeficient rats for the engraftment and expansion of heterologous hepatocytes.

A genetically modified cat produced through gene editing with a phenotype characterized by the substantial absence of the major cat allergen, Fel d I. The phenotype is conferred in the genetically modified cat by targeting either the gene sequence of the Fel d I locus or sequences flanking the coding sequence of the two contiguous Fel d I genes with specialized gene editing constructs. The genotype and phenotype of the genetically modified cat is transmissible to its offspring.

Compositions and methods for improving embryo development, treating idiopathic male factor infertility, and enabling infertile/sub-fertile/sterile men to father their own genetic offspring are provided. Typically, the methods include administering into a male or female gamete or fertilized embryo an effective amount of a compound that increases bioavailability of a TET protein to improve development of an embryo resulting from fertilization of the female gamete by a male gamete. The compound can be administered into the gamete or embryo before, during, or after fertilization. The compound can be administered by an injection such as intracytoplasmic injection. The compound and the male gamete can be administered in combination by intracytoplasmic sperm injection. Methods of making male gametes, and methods of modifying the genome of a male gamete or embryo using an effective amount of a gene editing composition to correct a gene mutation or anomaly in the genome thereof are also provided.

Described herein are rats with a hepatic deficiency comprising decreased function, activity, or expression of an enzyme in the tyrosine catabolic pathway (such as fumarylacetoacetate hydrolase), and methods of using the same for in vivo engraftment and expansion of heterologous hepatocytes, such as human hepatocytes, analysis of human liver disease, and analysis of xenobiotics. Also disclosed is the use of immunodeficient rats for the engraftment and expansion of heterologous hepatocytes.

The present invention relates to a human artificial chromosome which is genetically transmissible to the next generation with high efficiency and the method for using the same. More specifically, the present invention relates to: a human artificial chromosome in which an about 3.5 Mb to about 1 Mb region containing an antibody light chain gene derived from human chromosome 22 is bound to a chromosome fragment which is transmissible to a progeny through a germ line of a non-human animal, said chromosome fragment is derived from another human chromosome; a non-human animal carrying the human artificial chromosome and an offspring thereof; a method for producing the non-human animal; a method for producing a human antibody using the nonhuman animal or an offspring thereof; and a human antibody-producing mouse carrying the human artificial chromosome.

An object of the present invention is to provide a method which constantly enables organ regeneration for the purpose of achieving organ regeneration with higher efficiency. It has been discovered that, in a blastocyst complementation method, a next generation is born when a deficiency in an organ, such as pancreas and kidney, is complemented by injection of ES cells into a generated blastocyst, and further discovered that a transgenic animal having a pancreas or a kidney thus complemented can transmit the phenotype to the next generation as a founder. This discovery has revealed that organ regeneration can be accomplished by using such a founder. Thus, the present invention achieved the above-described object.

In some aspects, the present invention provides chimeric transferrin receptor (TfR) polynucleotides and polypeptides. In other aspects, this invention provides chimeric TfR transgenic animal models and methods of using the animal models to identify therapeutics that can cross the blood-brain barrier.

Factor IX proteins are described with an increase in the number of glycosylation sites and other modifications to provide Factor IX proteins that have higher specific activity and a longer useful clotting function relative to wild type or non-modified Factor IX protein.

The present invention relates to a vector comprising a nucleic acid sequence that encodes the APP protein and/or the PS1 protein or variants thereof. The invention also relates to a method for inducing the Alzheimer's disease in an animal using the vector of the invention and to animal model having the Alzheimer's disease obtained by said method.

The present invention provides the following: a vector for inserting a desired nucleic acid into a predetermined site of a nucleic acid comprising a region formed of a first nucleotide sequence, the predetermined site, and a region composed of a second nucleotide sequence, in the stated order in the 5-to-3 direction, wherein the vector comprises a region formed of the first nucleotide sequence, the desired nucleic acid, and the second nucleotide sequence in the stated order in the 5-to-3 direction; a kit that includes this vector; a method of inserting a nucleic acid comprising a step for introducing this vector into a cell; a cell acquired by this method; and an organism comprising this cell.