Caspase 3-associated apoptosis is induced by Dad-mediated Dpp signal attenuation.

optix2/3-GAL4; UAS-Dad (“optix>Dad”) eye disc stained for activated caspase 3 (“cas3*”). Abundant cas3* signal is detected in cells anterior to the differentiation wave-front (dashed line). The disc is counterstained with the nuclear marker DAPI. (b, b’) Close-up of a cas3*-positive region. Cas3* signal (b’: arrows) overlaps with pycnotic nuclei stained with DAPI (small, dense DAPI signal), indicating that cells enter an irreversible apoptotic process.

(PDF)