CD69 gene disruption by homologous recombination.

(A) Schematic representation of the partial restriction maps of the mouse genomic CD69 locus, the targeting construct, and the targeted allele. The exons of the wild-type CD69 gene are shown as solid bars, boundaries of homology between the wild-type gene and the targeting construct are denoted by thin lines. (B) Southern blot analysis of BamHI-digested tail DNA from wild-type (+/+) and heterozygous (+/−) or homozygous (-/-) CD69 mice were analyzed with a 2-kb HindIII-EcoRI fragment from the genomic Xba-EcoRI fragment mapping 5′of the targeting construct. The unmutated CD69 gene produced a 12-kb fragment, whereas the mutated allele results in a 9-kb fragment. (C) CD69 expression in wild-type, CD69 (+/−), and in CD69 (-/-) mice. Flow cytometry analysis of CD69 expression in thymus from wild type (+/+), heterozygous(+/−), or homozygous (-/-) CD69 mutant mice. (D) CD69 expression in spleen, lymph node, and peripheral blood lymphocytes from wild type (+/+) or CD69 (-/-) mutant mice. Cells were activated with PMA at 10 ng/mL for 15 hours. Cells were double-stained with anti-CD69 and anti-CD2 labeled monoclonal antibodies and analyzed by flow cytometry.