The following information accompanied a Df(2R)robl-c stock from Aaron Bowman (2/00) in the lab of Larry Goldstein, University of California at San Diego.
Aaron wrote:
'As for the breakpoints; let me give you some background info to this line.
Roblc was derived from a large mass 'local hop' experiment in which 5
p-element lines (l(2)k08901, l(2)k11012, l(2)k06904, l(2)k07433,
l(2)k11303) from the robl region were 'hopped' (with delta2-3) in mass (in
one large cross) then the progeny were outcrossed and checked for
complementation against robl. roblc was one of two robl alleles derived
from this scheme (the other is called roblb). I characterized both lines
by p-element rescue, inverse PCR rescue, and southern analysis. roblc is
a deficiency over the robl region; the right breakpoint we indicate in the
paper flanks the 3' end of the pLacW element. I have been able to get inv.
pcr rescue off of the 5' end to determine the left breakpoint, but the
analysis is difficult to interpret because there appear to be at least 2
different 5' p-element ends (i.e. I got 2 different sequences). One of
these sequences appears to be from the parental p-element, while the other
is not found within the genomic region around robl that we sequenced. Thus
my best guess is that we got a local hop which left a small portion of the
5' end of the parental p-element at the original locus; and then had an
insertion event which deleted a region around and including robl. We were
able to confirm that at least the region from the left breakpoint of
roblk to the right breakpoint of roblc are deleted by southern
analysis. This is where our analysis of the deficiency ended (since we only
cared that it broke at least to the left of the roblk breakpoint. You can
refer to the genomic map I provided in the paper to see what I'm talking
about. roblb appears to be derived from l(2)k08901 (it fails to
complement this and only this parental p-element line). The 5' rescues off
of roblb match one of the 5' rescues off of roblc; thus I believe this
may be the parental 5' end; and that both alleles are derived from
l(2)k08901. However, roblc complements l(2)k08901; so at the very least
the parental p-element is no longer intact in roblc. Thus if I were to
guess, the left breakpoint of roblc falls somewhere between the
l(2)k08901 and the left break of roblk.'
Note that 'roblk' is Df(2R)k10408 and that the paper he refers to is
Bowman et al. J. Cell Biol. 1999 146(1):165--180 (FBrf0109386).