FlyBase curator comment: this entry is used to capture phenotypic information when the particular allele (or allele combination) used by the author could not be determined but the context of the experiment suggests that the phenotype being described is some kind of loss of function.
Most embryos that are zygotically mutant for Deaf1 hatch and develop to late third instar larvae and form pupae, but they never eclose as adults. Pharate adults have no obvious morphological abnormalities.