Genomic organization and functional characterization of the alcohol dehydrogenase locus of Ceratitis capitata (Medfly).

Approximately 30 kb of genomic DNA enclosing the Adh locus from the medfly, Ceratitis capitata have been cloned and about 15 kb has been structurally and functionally characterized. The locus consists of two genes, Adh-1 and Adh-2, separated by an intergenic region, which is polymorphic in size ranging from approximately 6.4 kb to 8.

Molecular basis of the size polymorphism of the first intron of the Adh-1 gene of the mediterranean fruit fly, Ceratitis capitata.

The first intron of the gene encoding one of the alcohol dehydrogenase isoenzymes (ADH-1) in Ceratitis capitata is highly polymorphic in size. Five size variants of this intron were isolated from different strains and populations and characterized. Restriction map and sequence analysis showed that the intron size polymorphism is due to the presence or absence of (a) a copy of a defective mariner-like element, postdoc; (b) an approximately 550-bp 3' indel which exhibits no similarity to any known sequence; and (c) a central duplication of 704 bp consisting of part of the 3' end of the postdoc element, the region between postdoc and the 3' indel, and the first 20 bp of the 3' indel.