Disclosed herein, in certain embodiments, is a transgenic mouse expressing a fusion protein comprising OCT+ under a transcriptional control. In some embodiments, also disclosed herein include embryos, stem cells, and germline cells obtained from the transgenic mouse. In additional embodiments, disclosed herein include a method of generating the transgenic mouse and a method of assessing a product using an embryo obtained from the transgenic mouse.

Non-human animals, cells, methods and compositions for making and using the same are provided, wherein the non-human animals and cells comprise a humanized B-cell activating factor gene. Non-human animals and cells that express a human or humanized B-cell activating factor protein from an endogenous B-cell activating factor locus are described.

Methods and compositions are provided for modifying one or more target loci in a cell. Such methods comprise providing a cell comprising a first polynucleotide encoding a first selection marker operably linked to a first promoter active in the cell, wherein the first polynucleotide further comprises a first recognition site for a first nuclease agent. A first nuclease agent is introduced into a cell, wherein the first nuclease agent induces a nick or double-strand break at the first recognition site. Further introduced into the cell is a first targeting vector comprising a first insert polynucleotide flanked by a first and a second homology arm that correspond to a first and a second target site located in sufficient proximity to the first recognition site. At least one cell is then identified comprising in its genome the first insert polynucleotide integrated at the target locus.

Porcine animals, tissue and organs as well as cells and cell lines derived from such animals are provided that lack functional endogenous immunoglobulin loci and are deficient in immunoglobulin expression and B-cells. These animals are useful as model systems for research and for development of new pharmaceutical and biological agents. In addition, methods are provided to prepare such animals.

An sortase-mediated intercellular labeling method allowing for tracking ligand-receptor interaction both in vitro and in vivo; and uses thereof for tracking molecule interactions both in vitro and in vivo, identifying modulators of ligand-receptor interaction, identifying potential binding partners of a protein of interest, identifying B cells expressing high affinity B cell receptors to antigens, and identifying the antigen to which a T cell of interest binds.

Compositions and methods are provided for the treatment and/or prevention of an inflammatory and/or autoimmune disease or disorder.

Disclosed herein are conditioning regimens and methods for inducing MHC- or HLA-mismatched mixed chimerism by conditioning a recipient with radiation-free, low-doses of cyclophosphamide (CY), pentostatin (PT), and anti-thymocyte globulin (ATG) prior to transplantation of donor bone marrow cells. In certain embodiments, the donor bone marrow cells may be CD4+ T-depleted bone marrow cells. The conditioning regimens and methods may also include administering one or more populations of conditioning donor cells selected from donor CD4.sup.+ T-depleted spleen cells, donor CD8.sup.+ T cells, and donor G-CSF-mobilized peripheral blood mononuclear cells. The conditioning regimen is clinically acceptable and can be used for treating hereditary hematological diseases and autoimmune diseases, as well as for promoting organ transplantation immune tolerance.

Methods and compositions are provided for modifying one or more target loci in a cell. Such methods comprise providing a cell comprising a first polynucleotide encoding a first selection marker operably linked to a first promoter active in the cell, wherein the first polynucleotide further comprises a first recognition site for a first nuclease agent. A first nuclease agent is introduced into a cell, wherein the first nuclease agent induces a nick or double-strand break at the first recognition site. Further introduced into the cell is a first targeting vector comprising a first insert polynucleotide flanked by a first and a second homology arm that correspond to a first and a second target site located in sufficient proximity to the first recognition site. At least one cell is then identified comprising in its genome the first insert polynucleotide integrated at the target locus.

This invention relates to the engineering of animal cells, preferably mammalian, more preferably rat, that are deficient due to the disruption of tumor suppressor gene(s) or gene product(s). In another aspect, the invention relates to genetically modified rats, as well as the descendants and ancestors of such animals, which are animal models of human cancer and methods of their use.

The invention provides genetically modified non-human animals that express chimeric human/non-human MHC I polypeptide and/or human or humanized 2 microglobulin polypeptide, as well as embryos, cells, and tissues comprising the same. Also provided are constructs for making said genetically modified animals and methods of making the same. Methods of using the genetically modified animals to study various aspects of human immune system are provided.