FIG. 1.

Disruption of the mouse α9 gene by homologous recombination. (A) Structures of mouse α9 wild-type allele, targeting vector, and targeted allele. Two exons are shown as solid boxes. The expected fragment size after SacI digestion is 3.4 kb for the wild-type allele and 4.9 kb for the targeted allele. (B) Southern blot analysis of genomic DNA from mouse tail digested with SacI and hybridized with the external specific probe of mouse α9 indicated in panel A. (C) RT-PCR analysis of mRNA from α9^+/+ and α9^−/− mice. Total RNA was extracted from mouse liver and transcribed to complementary DNA (cDNA). A 95-bp fragment was amplified from α9^+/+ mouse but not from α9^−/− mouse using primers specific for wild-type α9 cDNA. (D) Western blotting of cell lysate of mouse liver with a polyclonal antiserum against α9. A band of the appropriate size to be α9 is demonstrated in α9^+/+ but not in α9^−/− mice. The positions of molecular mass markers (in kilodaltons) are shown to the right.