Although the cpz-1
transcript is present throughout development, it is least expressed in embryos and during L1 to L2 growth. The level of the cpz-1
transcript increased significantly prior to the L2/L3 molt at 16 h and decreased after the L2/L3 molt (~20 h), and then periodically increased before the L3/L4 molt (~24 h) and the L4/adult molt (~34 h). In addition, a significant increase in its level occurred during the period when the early part of embryogenesis takes place (~40 h after L1). During adulthood there is a 23-h period when the fertilized eggs go through the process of embryogenesis.