abdA phenotype

[kovalige at muohio.edu]

I'm looking at the expression of a gene within the midgut epithelium 
and its potential regulation by homeotic genes.  I did an in situ 
using late stage embryos derived from abdA[M1]/TM1, Me parents.  I've 
gotten some odd results that I'm not sure how to interpret.  One of my 
problems is that I'm not certain how to identify abdA[M1] homozygous 
embryos.  I know that abdA mutants lack the second and third midgut 
constrictions, and I can identify mutants at that particular stage.  
What do older or younger mutants look like?  Are there any unambiguous 
features that can be used to identify abdA mutants from wild-type 
embryos in whole mount in situs?  Are mutant embryos very similar to 
wild-type or are they wildly abnormal?  Do TM1 homozygotes have a 
distinctive mutant phenotype, or do they resemble wild-type embryos?  
I would appreciate any information you can give me.  

Gae Kovalick
Department of Zoology
Miami University
Oxford, OH  45056

email: kovalige at muohio.edu