The Cd19 promoter specifically directs expression at the earliest stages and throughout B-lymphocyte development and differentiation. A Cre cassette is inserted into the Cd19 exon 2, functionally disrupting the gene. Homozygous mice are Cd19-deficient, whereas heterozygous mice are phenotypically normal and can be used for specific deletion of floxed targets in B-lymphocytes. Mice that are homozygous deficient for Cd19 are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. A deficiency in the B-1 subset of B-lymphocytes is observed along with a concomitant reduction in serum IgM. Homozygous mice are severely impaired in their ability to respond to T-cell-dependent antigens and fail to form splenic germinal centers.
Because the targeted mutation was generated on 129P2-derived embryonic stem cells, and the Cd19 locus is near the Tyr locus on chromosome 7, the these CD19-deficient mice may be albino (white coat color/pink eyes) or light-agouti coat color with dark eyes.
View cre expression characterization.
