Figure 10.

Model of the roles of LIN-29 and its target genes in the hypodermis and intestine. In the hypodermis, lin-29 expression is regulated by the heterochronic pathway (HPC) acting through let-7 and lin-41. LIN-29 activates expression of many L4 and adult specific cuticle collagen (col) genes which contribute to the adult cuticle. Cuticle damage in the adult [e.g., in bli-1(RNAi) animals] signals through let-7 to increase expression of lin-29 and col genes. Dashed lines indicate that a mechanism is not yet known. Hypodermal LIN-29 also activates expression of signaling genes (grd-11 and grl-14 are shown as examples), which act to reduce expression of genes involved in fat metabolism in the intestine.