Targeted disruption of the Mst1 gene locus.

<p>(<b>A</b>) Targeting strategy used to disrupt the Mst1 locus. Homologous recombination (represented by ×) between the targeting vector and the Mst1 gene results in the replacement of exons 3–4 with the selection cassette. (<b>B</b>) Southern hybridization indicating proper gene targeting in the embryonic stem cell clones. Clone 1F3 was selected for blastocyst injections to generate chimeric animals which were bred to C57BL/6 (albino) females, and the resulting heterozygous offspring were interbred to produce homozygous Mst1 deficient mice; Lex-2 represents untransfected embryonic stem cell DNA. (<b>C</b>) The effect of Mst1 disruption on peripheral lymphocyte subsets. Peripheral blood cell subsets were stained with a panel of lymphocyte lineage-specific mAbs and quantitated by FACS. Values are expressed as mean ± SEM; n = 9 per group. Student's <i>t</i> test was used for group comparison.