Southern-blot analysis of ZmIPK1A. Genomic DNA was isolated from inbred line 5XH751 and digested with EcoRI, BamHI, BanII, NcoI, NsiI, and BsmI. The digested maize genomic DNA and λ phage DNA were separated on 0.8% agarose and transferred to Nylon membrane. The blot was probed with 32P-dCTP labeled ZmIPK1A and λ phage DNA. Black bars indicate the size and positions of the DNA Mr markers.