From pamela-geyer@XXXX Sat Jan 9  11:58:55  1999
To: Madeline Crosby <crosby@XXXX>
Subject: Re: yellow constructs -- extra fragment
Dear Madeline,
Thanks for you message. Yes, I knew about this. The way the original
construct was made, an approximately 2.0 kb Bgl II fragment in the 3' end
of the yellow gene was removed. Thus, these sequences are all sequences of
the region of yellow, there is just a discontinuity in these clones
relative to the genomic DNA. When I distribute plasmids to anyone, I tell
them of this change. However, people get the plasmids from other sources,
and not all of the original information is passed on.
Thus, I would not call this DNA an extra fragment, since it is still from
the yellow region.
I take it from your comments, you will enter a complete sequence of the
yellow clones in Flybase???
Thanks for your information!
Pam
> From crosby@XXXX Thu Jan 7  15:15:51  1999
> To: pamela-geyer@XXXX
> Subject: yellow constructs -- extra fragment
>
> Pam,
>
> Thought we should relay this to you. This extra fragment appears
> to be in both pBSX and in yS/GpUC8 (obtained via Ting Wu). You
> may know all about it already, but I wanted to get it officially
> into FlyBase, in order to correct some compiled sequences.
>
> --Lynn
>
> ----- Begin Included Message -----
>
> From crosby@XXXX Thu Jan 7  14:59:49  1999
> To: flybase-updates@XXXX
> Subject: pc regarding yellow constructs
> Cc: huetXXXX, crosbyXXXX
> X-Sun-Charset: US-ASCII
> Content-Length: 1530
>
> To: FlyBase
>
> From: Francois Huet, Madeline Crosby, Ryan Baugh
>
> We wish to report as a personal communication the following
> information regarding pP{Car20y} and derived constructs.
>
> It has been previously reported (Nassif et al., 1994, MCB  14:1613 )
> that the SalI y+ segment derived from pP{Car20y} is not 7.7kb as
> originally claimed, but approximately 7.9kb. It was established
> by Nassif et al. that the extra ~200bp are at the 3' end of the
> yellow segment.
>
> Using several constructs derived from pP{Car20y}, we have confirmed
> these results and have sequenced the unidentified fragment. The
> sequence is presented below, starting with the BglII site known to be
> at the 3'end of yellow, and ending with the SalI site used to clone
> into and out of pP{Car20y}. 19bp at the 3'end appear to be derived
> from a polylinker; the first 157bp are identical to sequence located
> 1.7kb downstream from the yellow fragment in cosmid clone DMC125H10
> (accession number AL023873; 21264-21420). Ligation of the yellow
> fragment with the 157bp fragment appears to have occurred at the
> BglII site at the 3' end of yellow and the BglII site at the 5' end
> of the 157bp fragment. A new BamHI site has been created at 163-168.
>
> Sequence:
>
> agatcttgtt tgggtgcagg gaaagttcaa cttaatcgct caatttgaga tcgcctggtc
> gcttgagatt cgactgtaat tgaaattttt gcttttgatc ggagccagac ttcagacggg
> gcaaacaaaa agactttgtt ggtggtaggg taggatccgt tgacctgcag gtcgac
>
> This extra fragment may also be present in mini-yellow and other
> constructs derived from pP{Car20y}.