Subject: Mad/Mnt in Drosophila
Dear Dr. Eisenman,
At the Drosophila conference in San Diego last week I was interested in two
posters from your laboratory describing a homolog of the vertebrate MAD
proteins in Drosophila. I talked with one of the presenters, so maybe she has
alerted you to this issue.
I wonder if your Drosophila protein is essentially the same as
GH28809p/ EG:114E2 . If so I believe this is in fact the ortholog of the
vertebrate MNT protein. I believe this because I have undertaken molecular
phylogenetic analyses of these two proteins, MAD and MNT, to determine why a
MAD ortholog we have detected as an EST in honey bees is not in the Drosophila
genome. It is also missing from the mosquito Anopheles gambiae genome that
recently became available, so was apparently lost near the origin of the order
Diptera. Instead both flies have clear orthologs of MNT. This is true both by
sequence comparisons of the alignable regions, plus the Drosophila
GJ28809p/ EG:114E2  proteins have a +/-200aa N-terminal region that fits better
with it being MNT than being MAD (although the annotation of this N-terminus
is not clear so maybe you can help clear that up \- there seem to be two
isoforms with two different N-termini, with ESTs for both \- perhaps these two
isoforms effectively function as both MNT and MAD).
In fact last night I came across a paper by Peyrefitte et al in Mechanisms of
Development last year (104; 99-104) noting that Drosophila MAD is missing and
that the above gene is the apparent ortholog of vertebrate MNT (I'll copy this
message to Rachel Drysdale of FYBASE in Cambridge, asking why this gene is not
yet annotated as Mnt in FLYBASE).
I think using the name to MNT would be better to avoid any confusion in the
future on this issue. In addition this would avoid confusion with the already
named Drosophila gene Mad (Mothers against dpp), which has precedence.
In case you are interested, below is the full-length aa sequence for the bee
MAD ortholog.
MSIAALLQAAEYIERREREAEHGYASTMPMPDDMRTVTKRPKTKKSQGSRTTHNELEKNRRAHLRNCLEKLKVLVPLG
PETSRHTTLGLLTKAKRFIKSLEERERKHAVHKEQLSREQRFLRRRLEQLTNQTGLHGLHGLHGLHGLSSSAPTGSSC
GPGAAAAAALLSKRRSVSECSLGTASSTSSTASSRNSDRSAGSPSVSESDEVDVIGYTSNQSDTDDHSSVQSSSDSGV
TMSTSRLTLSEMMDNL
Hugh
Subject: Re: Mad/Mnt in Drosophila
Hi Hugh,
>(I'll copy this
>message to Rachel Drysdale of FYBASE in Cambridge, asking why this gene is not
>yet annotated as Mnt in FLYBASE)
When we curated
FBrf0137013 == Peyrefitte et al., 2001, Mech. Dev. 104(1-2): 99--104
we noted a mention of  EG:114E2 , and that the authors referred to it at
least once as DmMnt, but did not rename it Mnt.
It seems to me, based on what you have written and what else we have in
the gene record for  EG:114E2 , that there is a good case for renaming
FBgn0023215 Mnt, and I will see to it that the symbol gets changed in
our files. It is the usual practise to overwrite the anonymous genome
project type symbols (such as  EG:114E2 ) with more biological names
when those appear in the literature, as in FBrf0137013. It was
probably just a lapse of concentration that meant that we missed this one.
Rachel.
Subject: Re: Mad/Mnt in Drosophila
Rachel, if you want to include a reference that my phylogenetic analyses
indicate that it is the ortholog of vertebrate MNT that's fine with me.
Hugh M. Robertson, Professor
Department of Entomology, University of Illinois at Urbana-Champaign
320 Morrill Hall, 505 S. Goodwin Ave., Urbana, IL 61801