Genomic Organization of a-Amylase Gene in High Lysine Opaque-2 Maize

Genomic DNA was isolated from 7-day old etiolated seedlings of normal and high lysine opaque-2 maize and purified by CsCI gradient. Purified DNA was found to be ∼48.5 kb in size. Restriction analysis of genomic DNA with EcoRI and Hindlll did not reveal any noticeable difference between normal and opaque-2 DNA. Southern blot analysis, using α-amylase probe, showed multiple bands. One of the hybridizing bands (∼4 kb) of genomic DNA was more intense in opaque-2 than in normal. This DNA was cloned into pUC 18 plasmid and presence of α-amylase was confirmed by Southern hybridization using α-amylase probe.