Yt. Ho et al., INTERACTING HOBO TRANSPOSONS IN AN INBRED STRAIN AND INTERACTION REGULATION IN HYBRIDS OF DROSOPHILA-MELANOGASTER, Genetics, 134(3), 1993, pp. 895-908
A transposable hobo element in the Notch locus of the Uc-1X chromosome
, which does not interfere with the normal expression of the locus, in
teracts with other hobo elements in the same X chromosome to produce N
otch mutations. Almost all of these mutations are associated with defi
ciencies, inversions or other rearrangements, and hobo elements are pr
esent at each of the breakpoints. The Uc-1 X chromosome produces the N
otch mutations at a rate of 4-8% in both sexes of flies in a strain th
at has been inbred for 96 generations. At least two-thirds of the muta
tions are produced in clusters suggesting that they have originated in
mitotic (premeiotic) germ cells of the Uc-1 inbred strain. The intera
ction of hobo elements in the Uc-1 X chromosome can be repressed by at
least two different mechanisms. One found in three inbred strains not
related to the Uc-1 strain involves a maternal effect that is not att
ributable to the actions or products of hobo elements. Repression by t
his mechanism is manifested by a clear reciprocal cross effect so that
the production of Notch mutations is repressed in the daughters of Uc
-1 males, but not in the daughters of Uc-1 females. The other mechanis
m apparently requires genetic factors and/or hobo elements in a partic
ular strain of Oregon-R; complete repression is present in both types
of hybrids between Uc-1 and this strain.