Conditional deletion of Asciz. (A) ASCIZ domain organization and conditional deletion strategy. The probe and fragment sizes for Southern blot analysis and primer locations (F1, R1, and R2) and product sizes for PCR genotyping are indicated. SCD, SQ/TQ cluster domain; TAD, transcription activation domain; ZF, Zinc finger. (B) Southern blot analysis of ASCIZ-Mx control and deleter tissues 4 wk, 16 wk, and 2 yr after poly(I:C) injection. Samples from four different controls (Mx1-Cre⁻Asciz^fl/fl) and six different deleters (Mx1-Cre⁺Asciz^fl/fl) are shown. SP, spleen; TH, thymus; TL, tail. (C) Western blot analysis of MACS-purified splenic B cells from single ASCIZ-Mb control and deleter mice. β-Catenin (CTNNB1) is used as loading control. Molecular mass standards are indicated on the right. (D) Kaplan-Meyer survival curve of ASCIZ-Mx deleters and controls for the indicated times after poly(I:C) injection. n = 28 for controls, which included a mixture of Mx1-Cre⁺Asciz^fl/+ and Mx1-Cre⁻Asciz^fl/fl mice, and n = 32 for Mx1-Cre⁺Asciz^fl/fl deleters. Note that there was no statistical difference between the curves and that all nonsurviving mice were sacrificed because of general well-being issues unrelated to neoplasia (seizures, malocclusions, eye infections, etc.). (E) Kaplan-Meyer survival curve of ASCIZ-Mb deleters (n = 14) and controls (n = 16; 10 Mb1/Mb1-Cre Asciz^+/+ plus 6 Mb1-Cre⁻Asciz^fl/fl).