Subject: location of gene "clipped"
I have mapped cp1 distal to asf11 (76C) by meiotic recombination.
The cytological location of cp (given as 77A-D) is based on the mistaken
belief that Df(3L)rdgC-co2 includes cp.  I believe that Df(3L)rdgC-co2
was induced on a marked third chromosome that carried the cp1 allele.
I have separated cp1 from Df(3L)rdgC-co2 by meiotic recombination.
One class of recombinants was Df(3L)rdgC-co2 and cp+ .  The reciprocal
class of recombinants was cp1, but was not Df(3L)rdgC-co2.
The classification of cpI5 as a gain-of-function allele was also based
on the belief that cp was deleted by Df(3L)rdgC-co2 and should be
reconsidered.
Jim Kennison
Subject: Re: location of gene "clipped"
Hi Jim,
just a follow on question here about what to do for map data for cp,
given that cp is not uncovered by Df(3L)rdgC-co2.
You say that asf1 (current map location 76B9) lies to the right of cp.
However in
FBrf0123112 == Lukinova et al., 1999, Genetics 153(4): 1789--1797
it is suggested (by failure of complementation with cp1 and cpI5)
that T(2;3)rdgCco6 causes an allele of cp.  The 3L break of
T(2;3)rdgCco6 is thought to be 77B1.  This seems to be on the basis
of cytological observation, and mapping to rdgC.
Given your mapping of cp by recombination, it seems likely that it is
not the 77B1 break of T(2;3)rdgCco6 that is causing the effect on cp,
but another case of there being a linked mutation.  In fact 
FBrf0052690 == Steele and O'Tousa, 1990, Neuron 4: 883--890
reports T(2;3)rdgCco6 and Df(3L)rdgC-co2 coming out of the same screen.
So it seems to me (please check my logic) that both T(2;3)rdgCco6 and
Df(3L)rdgC-co2 will carry the same separable cp1.
In light of this I will make alterations to the T(2;3)rdgCco6 record too.
I believe at this point we have no accurate cytological assessment of
the whereabouts of cp (other than to the left of asf1), but a definite
unknown is more valuable than a false known.
Best regards,
Rachel.
Subject: RE: location of gene "clipped"
Rachel,
I would agree that T(2;3)rdgCco6 was also induced on a chromosome that
already carried cp1.
We know that cp1 maps between st and asf1.  It complements Df(3L)81k19
73A;74F and Df(3L)kto2 76B1-2;76D5, which uncover st and asf1,
respectively.  That places cp between 74F and 76B.  Lindsley and Zimm
(1992) claim that cp is proximal to the 75D4-5 breakpoint of T(Y;3)L131
(according to V. Walker).
Jim
Subject: RE: location of gene "clipped"
Thanks Jim,
will add your further info to the pc
I yesterday added the V. Walker 'proximal to 75D4-5' mapping to the
gene record for clipped, however this is unsatisfactory because the
source (method) is not terribly clear - I just cited Lindley and Zimm
as the source.
The further information you provide below is much better thank you -
though we have just missed a cut off for an update so unfortunately it
will have to wait until the next round to get to the public pages.
Thanks again for your help,
Rachel.