Dear Rachel,
I have been perusing the genes entry for Dichaete in FlyBase and notice
that the designation loD (lethal of Dichaete) is still in use. It is now
absolutely clear that all alleles designated loD (loD3, loD4, loD6,
loD7, loD8, loD10 and loDLG9 are alleles of Dichaete. For the
dominant alleles (3,4,6,7 and 10) these are associated with breaks in 3'
regulatory sequences which result in the tissue specific loss of Dichaete
expression in the embryo. (loD10 = In(3L)D10 70A1-2;70D1-2D). Dr8
is a similar rearrangement with a 3' break but has no dominant phenotype.
All of these alleles are lethal in combination with point alleles of
Dichaete, e.g Dr72 and small deletions which only remove Dichaete
sequences such as Dr513.
The point allele Dr72, near null protein levels, is phenotypically null in
segmentation.
The small deletion Dr513 deletion from p-element P{PZ}rJ375 removes 5' half of
Dichaete transcription unit.
Best wishes
Steve
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Dr Steven Russell
Department of Genetics
University of Cambridge
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