Some embryos lacking both maternal and zygotic sina function have obvious defects in overall morphology, while others have no defects. In embryos with normal morphology but severe defects in the peripheral nervous system, about 75% of the neurons and 60% of the sheath cells in the abdominal segments are missing. In the dorsal-most region of the abdominal hemisegments 90% of es organs are still present, suggesting that the reduction in number of neurons and sheath cells is due to cell fate transformation.

Homozygotes lack R7 cells, and rl^Sem/+;sina^unspecified/sina^unspecified flies have the sina^unspecified mutant phenotype.