Abstract: Multivalent antigen-binding proteins comprising two or three or four or more immunoglobulin heavy chain variable domain binding domains are provided, as are methods for making them, nucleic acid constructs, and cell lines for making them. Proteins comprising two or three or four or more different heavy chain variable domains that lack an immunoglobulin variable domain are provided. Proteins comprising two or three or four or more different heavy chain variable domains that associate with the same immunoglobulin light chain variable domain are also provided.

Abstract: Methods are provided herein for assembling at least two nucleic acids using a sequence specific nuclease agent (e.g., a gRNA-Cas complex) to create end sequences having complementarity and subsequently assembling the overlapping complementary sequences. The nuclease agent (e.g., a gRNA-Cas complex) can create double strand breaks in dsDNA in order to create overlapping end sequences or can create nicks on each strand to produce complementary overhanging end sequences. Assembly using the method described herein can assemble any nucleic acids having overlapping sequences or can use a joiner oligo to assemble sequences without complementary ends.

Abstract: 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 a proliferation-inducing ligand gene. Non-human animals and cells that express a human or humanized a proliferation-inducing ligand protein from an endogenous a proliferation-inducing ligand locus are described.

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: 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, 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: A method for engineering and utilizing large DNA vectors to target, via homologous recombination, and modify, in any desirable fashion, endogenous genes and chromosomal loci in eukaryotic cells. These large DNA targeting vectors for eukaryotic cells, termed LTVECs, are derived from fragments of cloned genomic DNA larger than those typically used by other approaches intended to perform homologous targeting in eukaryotic cells. Also provided is a rapid and convenient method of detecting eukaryotic cells in which the LTVEC has correctly targeted and modified the desired endogenous gene(s) or chromosomal locus (loci) as well as the use of these cells to generate organisms bearing the genetic modification.

Abstract: The invention provides genetically modified non-human animals that express a humanized MHC II protein (humanized MHC II ? and ? polypeptides), as well as embryos, cells, and tissues comprising the humanized MHC II protein. Also provided are constructs for and methods of making the genetically modified non-human animals. Methods of using the genetically modified non-human animals to study various aspects of the human immune system are provided.

Abstract: 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.

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: 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: 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 a humanized MHC II protein (humanized MHC II ? and ? polypeptides), 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: 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: Genetically modified non-human animals are provided that express an immunoglobulin variable domain that comprises at least one histidine, wherein the at least one histidine is encoded by a substitution of a non-histidine codon in the germline of the animal with a histidine codon, or the insertion of a histidine codon in a germline immunoglobulin nucleic acid sequence. Immunoglobulin genes comprising histidines in one or more CDRs, in an N-terminal region, and/or in a loop 4 region are also provided. Immunoglobulin variable domains comprising one or more histidines (e.g., histidine clusters) substituted for non-antigen-binding non-histidine residues. Non-human animals that are progeny of animals comprising modified heavy chain variable loci (V, D, J segments), modified light chain variable loci (V, J segments), and rearranged germline light chain genes (VJ sequences) are also provided. Non-human animals that make immunoglobulin domains that bind antigens in a pH-sensitive manner are provided.

Abstract: 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.

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: 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: 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.