The sequence determination of several genomic clones isolated from the
Mediterranean fruitfly Ceratitis capitata identified the existence of
opa-like repeats, often more than one being clustered in small chromo
somal segments. These repeats have previously been shown to consist of
stretches of tandemly reiterated glutamine-encoding residues, and the
y are found in multiple genes of several organisms. Most of the repeat
s described here are flanked or interrupted by stop codons in all read
ing frames and, thus, could not possibly be part of protein-coding seq
uences. Furthermore, these repeats, of which there are several hundred
in the genome of the Medfly, can be used effectively for the determin
ation of sequence polymorphisms, providing a convenient approach to ob
tain additional landmarks for the construction of genomic maps of this
economically important insect.