Abstract: Nucleic acid molecules and single-domain antibody applications are provided. The nucleic acid molecules include a transgenic host animal immunoglobulin genes or parts of immunoglobulin genes. Main characters are: it comprises the transgenic host animal IgH 5?-enhancer, IgM switch region (S?), and IgM sequences, specifically, all the IgM sequences are originated from the transgenic host animal, and the CH1 sequences of the IgM is deleted (IgM-dCH1). The regulatory control sequences of IgG are also derived from the transgenic host animal including S?, TM1, TM2, PolyA sequences, etc., and IgG C? sequences (Hinge, CH2 and CH3) are human sequence (Ig?-dCH1). The present invention ensures normal B-cell development in transgenic animal, and the transgenic animal expresses human single-domain antibodies, reducing the subsequent antibody humanization process and improving the druggability of the antibodies.

Abstract: Nucleic acid molecules include immunoglobulin genes or parts of immunoglobulin genes. The nucleic acid molecules includes the IgM gene (IgHC?) and IgM switch region (S?). The sequences of the S? and the IgHC? are both derived from a transgenic host animal. In this invention, human antibodies are directly generated and no humanization process is required, and the human antibody druggability is increased. The transgenic human antibody mouse has normal early B?cell development, maturation and the B?cell number in comparison with that of wild type animal, thereby facilitating the differentiation of the B?cells. The specificity and diversity of the produced antibody are improved; and the efficiency for screening the therapeutic antibody is improved.

Abstract: The present invention provides in a first aspect a mouse in which the ? (lambda) light chain locus has been functionally silenced. In one embodiment, the mouse ? light chain locus was functional silenced by deletion of gene segments coding for the ? light chain locus. In a further aspect, a mouse containing functionally silenced ? and ? (kappa) L chain loci was produced. The invention is useful for the production of antibodies, for example heterologous antibodies, including heavy chain only antibodies.

Abstract: The present invention provides in a first aspect a mouse in which the ? (lambda) light chain locus has been functionally silenced. In one embodiment, the mouse ? light chain locus was functional silenced by deletion of gene segments coding for the ? light chain locus. In a further aspect, a mouse containing functionally silenced ? and ? (kappa) L chain loci was produced. The invention is useful for the production of antibodies, for example heterologous antibodies, including heavy chain only antibodies.

Abstract: The present invention provides in a first aspect a mouse in which the ? (lambda) light chain locus has been functionally silenced. In one embodiment, the mouse ? light chain locus was functional silenced by deletion of acne segments coding for the ? light chain locus. In a further aspect, a mouse containing functionally silenced ? and ? (kappa) L chain loci was produced. The invention is useful for the production of antibodies, for example heterologous antibodies, including heavy chain only antibodies.

Abstract: The present invention provides in a first aspect a mouse in which the ? (lambda) light chain locus has been functionally silenced. In one embodiment, the mouse ? light chain locus was functional silenced by deletion of gene segments coding for the ? light chain locus. In a further aspect, a mouse containing functionally silenced ? and ? (kappa) L chain loci was produced. The invention is useful for the production of antibodies, for example heterologous antibodies, including heavy chain only antibodies.

Abstract: The present invention provides in a first aspect a mouse in which the ? (lambda) light chain locus has been functionally silenced. In one embodiment, the mouse ? light chain locus was functional silenced by deletion of gene segments coding for the ? light chain locus. In a further aspect, a mouse containing functionally silenced ? and ? (kappa) L chain loci was produced. The invention is useful for the production of antibodies, for example heterologous antibodies, including heavy chain only antibodies.

Abstract: The invention relates to mice having functionally silenced endogenous lambda (?) and kappa (?) L-chain loci, comprising antibody-producing cells in which the CH1 domain is functionally silenced, either via spontaneous processes in somatic antibody-producing cells or due to germline deletion of the CH1 domain. Mice of the invention are capable of producing H-chain-only antibody lacking a functional CH1 domain; transgenic human heavy-chain-only antibodies lacking a functional CH1 domain can be produced following insertion into the mouse of an artificial locus with human heavy chain V, D and J segments and a constant region, which is preferably a modified constant region with alterations in, around or upstream of a CH1 domain and/or removal of a CH1 domain.

Abstract: The present invention provides in a first aspect a mouse in which the ?(lambda) light chain locus has been functionally silenced. In one embodiment, the mouse ? light chain locus was functional silenced by deletion of gene segments coding for the ? light chain locus. In a further aspect, a mouse containing functionally silenced ? and ? (kappa) L chain loci was produced. The invention is useful for the production of antibodies, for example heterologous antibodies, including heavy chain only antibodies.

Abstract: The present invention provides in a first aspect a mouse in which the ? (lambda) light chain locus has been functionally silenced. In one embodiment, the mouse ? light chain locus was functional silenced by deletion of gene segments coding for the ? light chain locus. In a further aspect, a mouse containing functionally silenced ? and ? (kappa) L chain loci was produced. The invention is useful for the production of antibodies, for example heterologous antibodies, including heavy chain only antibodies.