Complex organization of zein genes in maize

We have examined the fragments of maize nuclear DNA that are homologous to three cloned cDNAs prepared from zein mRNA. Southern blots of high molecular weight (greater than 40 kb) maize nuclear DNA cleaved with BamHI, HindIII or EcoRI were hybridized to three zein cDNA plasmid probes. Multiple restriction fragments in a wide range of size classes were observed to hybridize with all three probes. Our results indicate the occurrence of families of genes in the maize genome that are related by their sequences to a given zein mRNA sequence.