"In the absence of any hs-
egl-20, the QL and QR descendants are unable to express
mab-5::lacZ in
egl-20(
n585) animals (top panels). After an intermediate dose of hs-
egl-20 (10 min pulse), the QL descendants have turned on
mab-5::lacZ expression, whereas many of the QR descendants have not (middle panels). We never observed animals in which
mab-5::lacZ was expressed in the QR but not QL descendants. At high doses of hs-
egl-20 (30 min pulse),
mab-5::lacZ is expressed in both QL and QR descendants (bottom panels). This
mab-5::lacZ fusion is expressed in all L1 cells in which
mab-5 is predicted to function genetically(Salser and Kenyon, 1992)."