Structural polymorphism of the luciferase gene in the firefly, Luciola lateralis

To study the structural features of genes for luciferase in Luciola lateralis, two different, functional luciferase genes, Luc1 and Luc2, were cloned and their nucleotide sequences were determined. The two genes were nearly identical, but a deletion of 128 bp was found in the 5′ upstream region of Luc2, and minor deletions and additions were also found in the 3′ downstream region. Seven base substitutions in the coding region produced two amino acid residue differences between the two genes. Southern blot analysis of genomic DNA isolated from 33 individual fireflies revealed that 26 were homozygous for the Luc1 gene and one was homozygous for Luc2. The others were heterozygotes with two, or even three, different alleles for the luciferase gene.