Homozygous embryos exhibit wild type cuticle structures but fail to exhibit muscle contraction waves. Syx1A¹⁷/Syx1A^15ts transheterozygotes produce progeny that exhibit reduced viability, rough eyes (disrupted ommatidial array, ommatidia may be missing, fused, improperly rotated or misaligned) and notching along the posterior margin of the wing.