Disrupt posterior and dorsoventral patterning in embryos. Disrupt organisation of developing microtubules during stages 8 to 10. Developmental onset of microtubule-dependent ooplasmic streaming is affected causing premature ooplasmic streaming in the mutant ovaries. The progress and termination of streaming is unaffected.

Variable expansion (dorsalization) of dorsal appendages, at expense f main body shell. Absence of polar granules, pole cells and abdominal segments in embryos.

spir²/spir[+] is a non-enhancer of phenotype of ct^L188

spir²/spir[+] is a non-enhancer of phenotype of ct^C145

spir² is a non-enhancer of phenotype of ct^C145