egl-18 is asymmetrically expressed in larval seam division daughters with stronger expression in the posterior seam-fated cells in which the Wnt pathway is activated. All ten seam cells in newly hatched L1 larvae showed strong
egl-18 expression. After their first division,
egl-18::mCherry expression was asymmetric between the daughters, with stronger expression in the posterior daughters that maintain the seam cell fate. Expression in the anterior daughter faded after division, before the hypodermal daughters moved out of the seam cell line. During the L2 stage, several seam cells undergo a symmetric expansion division, generating two seam daughters and increasing the seam cell number from 10 to 16 (Sulston and Horvitz, 1977). In the early L2, strong symmetric expression of
egl-18::mCherry was seen in both seam-fated daughters of these divisions. When these seam-fated daughters underwent their subsequent L2 and L3 stage asymmetric divisions, reporter expression faded in their anterior, hypodermal-fated daughters as observed in the L1 stage. In the adult, differentiated seam cells continue to show strong expression of the
egl-18::mCherry reporter as described previously (Budovskaya et al., 2008).