TheposteriorgutoftheDrosophilaembryo,consistingofhindgutandMalpighiantubules,providesasimple,well-definedsystemwhereitispossibletouseageneticapproachtodefinecomponentsessentialforepithelialmorphogenesis.WereviewheretheadvantagesofDrosophilaasamodelgeneticorganism,themorphogenesisoftheepithelialstructuresoftheposteriorgut,andwhatisknownaboutthegeneticrequirementstoformthesestructures.Inoverview,primordiaarepatternedbyexpressionofhierarchiesoftranscriptionfactors;thisleadstolocalizedexpressionofcellsignalingmolecules,andfinally,totheleastunderstoodstep:modulationofcelladhesionandcellshape.Wedescribeapproachestoidentifyadditionalgenesthatarerequiredformorphogenesisofthesesimpleepithelia,particularlythosethatmightplayastructuralrolebyaffectingcelladhesionandcellshape.
