Figure 3.

Perdurance of β-Galactosidase Signal in ryxho25 Cells That Previously Expressed engrailed

Stage 10 embryo stained with anti-engrailed (red) and anti-β-galactosidase (green). In the ryxho25 line, β-galactosidase is expressed from an engrailed promoter and closely follows the engrailed pattern of expression. But because β-galactosidase is a more stable protein, its signal perdures longer than the engrailed signal. Posterior to the engrailed stripes, cells contain β-galactosidase and no detectable engrailed. Notice also cells with a very low level of engrailed signal (arrow). These cells always contain β-galactosidase.