Patent ID: 9629347
Date: 2017-04-25
CPC Classifications: A01K,C07K,G01N

Claim:
1. A genetically modified mouse whose genome comprises a replacement of a mouse genomic segment comprising exons 3-6 of an endogenous mouse B-cell Activating Factor (Baff) gene with a human genomic segment comprising exons 3-6 of a human BAFF gene to form a humanized Baff gene, wherein the replacement is at an endogenous mouse Baff locus, wherein the humanized Baff gene is under control of the mouse Baff promoter at said endogenous mouse Baff locus, and expresses in said mouse a humanized Baff protein comprising an extracellular portion of the human BAFF protein encoded by said human BAFF gene and an intracellular portion of the mouse Baff protein encoded by said mouse Baff gene, wherein the coding exons of the humanized Baff gene consist of exons 1 and 2 of said endogenous mouse Baff gene, and exons 3-6 of said human BAFF gene.