Subject: dAPC2 curation
Dear Bill,
I've just donated another allele of dAPC2, d40, to the
Bloomington Stock Center and noticed that the Flybase curation for
both this allele and the first dAPC2 allele, delta-S, was a little
inaccurate. The original allele my lab isolated, delta-S, is
temperature sensitive but even at the restrictive temperature it is
homozygous viable in the first generation. Homozygous mutant flies
mated to each other will produce 100% lethal embryos, all showing the
excess naked cuticle typical of ectopic Wg pathway activity. At 18
degrees, the homozygous mutant (maternal/zygotic) embryos are
essentially wild-type and the flies can be maintained as a homozygous
stock. This is experimentally convenient, but we have since found
that the phenotype at restrictive temperature is not equivalent to a
null phenotype. We've more recently isolated a more severe allele,
d40. This allele is not temperature sensitive, but is still
homozygous viable in the first generation. Homozygous mutant flies
mated together produce embryos showing a more complete excess naked
cuticle phenotype than that produced by the delta-S stock. Thus we
consider this a more severe allele for the locus, although we suspect
it is still not a null since we can detect protein with the dAPC2
antibody. The molecular lesion in d40 is a stop codon replacing
cysteine 677, so it is a fairly late truncation.
I've sent this allele to Eric Wieschaus' lab and shared it
with Mark Peifer in a collaboration. The first published reference
to the d40 allele is:
McCartney, B.M., McEwen, D.G., Grevengoed, E., Maddox, P., Bejsovec,
A., Peifer, M. (2001) Drosophila APC2 and Armadillo participate in
tethering mitotic spindles to cortical actin. Nature Cell Biol.
3(10):933--938
The reference to which Flybase attributes d40 (Ahmed et al.
2002) is a later publication from Eric's lab where they use it to
show that APC1 and APC2 are partially redundant, which accounts for
the F1 viability of the APC2 mutations. Mark's lab has a similar
paper showing this, also using the d40 allele, which has just come
out:
Akong K, Grevengoed E, Price M, McCartney B, Hayden M, DeNofrio J,
Peifer M. (2002) Drosophila APC2 and APC1 play overlapping roles in
Wingless signaling in the embryo and imaginal discs. Dev Biol.
250(1):91 \- 100.
Could the d40 allele entry be updated to include the
molecular data (personal communication from me), the correct primary
reference, an indication that this is the most severe allele
available at the moment, and eventually the Bloomington stock number
when Kevin and Kathy have it ready?
Thanks!
\-- Amy
\--
Amy Bejsovec, Ph.D.
Duke University
Dept. of Biology/DCMB Group
Box 91000
B336 LSRC, Research Dr.
Durham, NC 27708-1000