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.
The longitudinal connectives that normally run through the tritocerebral neuromere are missing or reduced in homozygous embryos. The tritocerebral commissure is completely missing and no longitudinal connectives project through the mutant domain. The frontal connectives project ectopically into more anterior brain neuromeres. The mandibular commissure is present.