The snRNA:U6:96Ac promoter drives expression of a guide RNA (gRNA) which targets wls, within the signal sequence.
Most embryos from wlsgRNA.snRNA:U6:96Ac Zzzz\Cas9nos.cPa females arrest at the end of embryogenesis with segment polarity phenotypes.
wlsgRNA.snRNA:U6:96Ac flies which express Zzzz\Cas9Scer\UAS.T:Uuuu\nls6 under the control of Scer\GAL4en.PU from the second larval instar onwards develop into viable adults with pronounced notches in the posterior half of the wing.