Tg(Igh-VHyHEL10/Ighm/Ighd)2Ccg

Fertilized mouse oocytes were microinjected with a mouse immunoglobulin heavy chain (Igh) transgene construct whose rearranged Igh-VDJ segments were derived from the HyHEL10 hybridoma cell line, which produces a high affinity monoclonal antibody to chicken lysozyme (commonly called hen egg lysozyme (HEL)). In the transgene, the sequence encoding the IgG1 heavy chain constant region of HyHEL10 has been replaced by the mouse Ighm (mu) switch region followed by a genomic DNA construct encoding the Ighm (mu) and Ighd (delta) constant regions of the Igha allotype. Expression of the transgene is driven by the promoter upstream of the leader sequence of Igh-V. Line 2 was estimated by Southern blot analysis to carry ~4 copies of the Igh construct. (A similarly derived immunoglobuline kappa light chain (Igk) construct was co-injected, but it failed to integrate in this line.) FACS analysis demonstrated that splenic B cells from these transgenic mice co-express transgene-encoded IgHmu and IgHdelta B cell receptors on their plasma membranes; the transgenic heavy chains are associated with various immunoglobulin light chains derived from endogenous light chain genes. (J:78308, J:132751)