Hi Rachel (?):
FlyBase persists with a confusion between linotte and derailed, which
should be corrected. Below is an attempt to clarify the issues, which I
also have sent to Interactive Fly.
.
Here's the linotte story as we see it:
1. The linotte transcript is novel (i.e., not derailed), and hs-induced
expression of a lio+ transgene in adults is sufficient to rescue fully the
adult learning defect of lio1 mutants (Bolwig et al.,1995).
2. The original lio1 P element mutation (as described by Dura et al.,
1993) is inserted 800 bp downstream of the linotte transcription unit,
perhaps in the 5'UTR of derailed. In fact, a P element allele of derailed,
isolated by John Thomas' lab, is inserted 6 bp away from our lio1 allele.
Hence, one might expect the lio1 mutation to create some sort of derailed
phenotype.
3. Dura's group has generated an excision-deletion of derailed by
mobilizing lio1. They call this deletion allele, lio2. They have shown
that (i) lio2 molecularly deletes derailed but not linotte and (ii) the
anatomical defects of lio2 are more severe than those of lio1.
4. Most mutant analyses by Dura's group, whether they be anatomical or
especially molecular (i.e. rescue), have been done on lio2, thereby
complicating everything.
5. Lio2 produces a more severe learning defect than lio1. Since the
anatomical defect of lio2 also is more severe than lio2, I assume that the
lower learning score in lio2 is caused not by a mechanistic effect on
learning but rather by and additional effect on the anatomy of mushroom
bodies (and who knows were else).
Hope this helps.
Cheers,
Tim