Tg(mIGHMdeltaV)1Corc

The deltaVmum transgene construct was derived from a rearranged human heavy-chain gene modified (by deletion of the cleavage and polyadenylation signals) so it can produce only the membrane-bound, and not the secreted, mu constant region (Cmu). The V-segment leader exon (L) was joined directly to an 11-kb fragment containing the IGH enhancer and Cmu exons and enhancer, deleting the V(D)J exon. As expected, no human IGmu chains are detected by ELISA in sera from these mice. Transgene-derived mRNA is detected in the spleens of mice of this transgenic line, and spleen cells can be identified by FCM analysis that express both the B cell lineage-specific marker, B220, and the truncated human IGmu chain on their surfaces. (J:135417)