October 5, 1982
Dear Dr. Georgiev:
Our laboratory has recently become interested in the transposition of mobile genetic elements of Drosophila in view of the structural similarities of their integrated and unintegrated forms to the forms of retroviral DNA.  We are currently surveying the known mobile elements to determine the abundance of free forms, with a view towards more complete structural analysis of the free DNA and an examination of the mechanism(s) by which the free forms arise.  We would very much like to have a look at mdg-1 and mdg-3 in this regard, and David Finnegan suggested that we write directly to you to ask for molecular clones of these elements.  Would you be able and willing to provide us with either the appropriate bacteria carrying such clones or cloned DNA that we can use to transform cells?  (In view of the distance, the latter procedure would probably be preferable.)
With many thanks and best regards,
Harold E. Varmus, M.D.
Professor