Abstract: Genetically modified mice and methods for making an using them are provided, wherein the mice comprise a replacement of all or substantially all immunoglobulin heavy chain V gene segments, D gene segments, and J gene segments with at least one light chain V gene segment and at least one light chain J gene segment. Mice that make binding proteins that comprise a light chain variable domain operably linked to a heavy chain constant region are provided. Binding proteins that contain an immunoglobulin light chain variable domain, including a somatically hypermutated light chain variable domain, fused with a heavy chain constant region, are provided. Modified cells, embryos, and mice that encode sequences for making the binding proteins are provided.

Abstract: Non-human animals, e.g., mammals, e.g., mice or rats, are provided comprising an immunoglobulin heavy chain locus that comprises a rearranged human immunoglobulin heavy chain variable region nucleotide sequence. The rearranged human immunoglobulin heavy chain variable region nucleotide sequence may be operably linked to a heavy or light chain constant region nucleic acid sequence. Also described are genetically modified non-human animals comprising an immunoglobulin light chain locus comprising one or more but less than the wild type number of human immunoglobulin light chain variable region gene segments, which may be operably linked to a light chain constant region nucleic acid sequence. Also provided are methods for obtaining nucleic acid sequences that encode immunoglobulin light chain variable domains capable of binding an antigen in the absence of a heavy chain.

Abstract: The invention provides genetically modified non-human animals that express chimeric human/non-human T cell co-receptor polypeptides (e.g., CD4, CD8?, CD8?), 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.

Abstract: Non-human animals, and methods and compositions for making and using the same, are provided, wherein said non-human animals comprise a humanization of an endogenous cluster of differentiation (CD) gene, in particular a humanization of a CD47 gene. Said non-human animals may be described, in some embodiments, as having a genetic modification to an endogenous CD47 gene so that said non-human animals express a CD47 polypeptide that includes a human portion and a non-human portion (e.g., a murine portion).

Abstract: The invention provides a genetically modified non-human animal that comprises in its genome unrearranged T cell receptor variable gene loci, as well as embryos, cells, and tissues comprising the same. Also provided are constructs for making said genetically modified non-human animal and methods of making the same. Various methods of using the genetically modified non-human animal are also provided.

Abstract: 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 the human immune system are provided.

Abstract: 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.

Abstract: 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.

Abstract: The invention provides genetically modified non-human animals that express chimeric human/non-human T cell co-receptor polypeptides (e.g., CD4, CD8?, CD8?), 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.

Abstract: 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.

Abstract: Genetically modified mice and methods and compositions for making and using the same are provided, wherein the genetic modification comprises humanization of an Fc?RI protein.

Abstract: Genetically modified mice are provided that express human ? variable (hV?) sequences, including mice that express hV? sequences from an endogenous mouse ? light chain locus, mice that express hV? sequences from an endogenous mouse ? light chain locus, and mice that express hV? sequences from a transgene or an episome wherein the hV? sequence is linked to a mouse constant sequence. Mice are provided that are a source of somatically mutated human ? variable sequences useful for making antigen-binding proteins. Compositions and methods for making antigen-binding proteins that comprise human ? variable sequences, including human antibodies, are provided.

Abstract: Genetically modified non-human animals expressing human SIRP? and human IL-15 from the non-human animal genome are provided. Also provided are methods for making non-human animals expressing human SIRP? and human IL-15 from the non-human animal genome, and methods for using non-human animals expressing human SIRP? and human IL-15 from the non-human animal genome. These animals and methods find many uses in the art, including, for example, in modeling human T cell and/or natural killer (NK) cell development and function, in modeling human pathogen infection of human T cells and/or NK cells, and in various in vivo screens.

Abstract: Non-human animals, tissues, cells, and genetic material are provided that comprise a modification of an endogenous non-human heavy chain immunoglobulin sequence and that comprise an ADAM6 activity functional in a mouse, wherein the non-human animals express a human immunoglobulin heavy chain variable domain and a cognate human immunoglobulin ? light chain variable domain.

Abstract: Non-human animals, tissues, cells, and genetic material are provided that comprise a modification of an endogenous non-human heavy chain immunoglobulin sequence and that comprise an ADAM6 activity functional in a mouse, wherein the non-human animals express a human immunoglobulin heavy chain variable domain and a cognate human immunoglobulin ? light chain variable domain.

Abstract: Genetically modified non-human animals and methods and compositions for making and using the same are provided, wherein the genetic modification comprises a humanization of an endogenous signal-regulatory protein gene, in particular a humanization of a SIRP? gene. Genetically modified mice are described, including mice that express a human or humanized SIRP? protein from an endogenous SIRP? locus.

Abstract: Genetically modified non-human animals comprising a humanized interleukin-15 (IL-15) gene. Cells, embryos, and non-human animals comprising a human IL-15 gene. Rodents that express humanized or human IL-15 protein.

Abstract: Non-human animals with humanized immunoglobulin loci and methods of using them in vaccine design are described, as well as methods for making broadly neutralizing antibodies against infectious agents and pathogens are provided. Non-human animals with humanized immunoglobulin loci used in B-cell-lineage immunogen design in vaccine development are provided, as are methods of carrying out such design.

Abstract: Genetically modified non-human animals and methods and compositions for making and using them are provided, wherein the genetic modification comprises a deletion of the endogenous low affinity Fc?R locus, and wherein the mouse is capable of expressing a functional FcR?-chain. Genetically modified mice are described, including mice that express low affinity human Fc?R genes from the endogenous Fc?R locus, and wherein the mice comprise a functional FcR?-chain. Genetically modified mice that express up to five low affinity human Fc?R genes on accessory cells of the host immune system are provided.

Abstract: Non-human animals, tissues, cells, and genetic material are provided that comprise a modification of an endogenous non-human heavy chain immunoglobulin sequence and that comprise an ADAM6 activity functional in a mouse, wherein the non-human animals express a human immunoglobulin heavy chain variable domain and a cognate human immunoglobulin ? light chain variable domain.