Construct: D.melanogaster per Thr-Gly repeat has been replaced with Dsim\per Thr-Gly repeat.
A SstI-BamHI fragment (carrying the Thr-Gly repeat) of D.simulans Dsim\per is substituted into D.melanogaster per+t13.2.
13.2kb of D.melanogaster per with the central 700bp thr-gly repeat region replaced by that of D.simulans.