Lethality acts in the first larval instar. Overall morphology of Bolwig's organ and nerve are normal in mutant larvae. Wild type foraging larvae show strong tendency towards photonegativity in a "Darth Vader" light avoidance assay. Homozygous mutants are less photonegative and hemizygous mutants are photoneutral.
Transheterozygotes with βTub60D4 and βTub60DP126 are viable but sterile.
Allelic series of mutations: βTub60D2 > βTub60D3 > βTub60D10 > βTub60D9 = βTub60D6 > βTub60D8 = βTub60D7 > βTub60Dsk > βTub60D11 > βTub60D5 > βTub60D1 > βTub60D4 > βTub60DP126.