Embryos exhibit the class IV phenotype. Expression of two copies causes transformation of T1 to a T2 identity with complete loss of the T1 beard, head segments are also transformed to a T2 identity (all normal head structures are missing and two or three T2-like denticle belts are seen on the head). Embryos also exhibit an absence of Keilin's organs, shortened denticle belts and a failure of germ band retraction.