%0 Journal Article %A Florian Aeschimann %A Anca Neagu %A Magdalene Rausch %A Helge Großhans %T let-7 coordinates the transition to adulthood through a single primary and four secondary targets %D 2019 %R 10.26508/lsa.201900335 %J Life Science Alliance %P e201900335 %V 2 %N 2 %X The juvenile-to-adult (J/A) transition, or puberty, is a period of extensive changes of animal body morphology and function. The onset of puberty is genetically controlled, and the let-7 miRNA temporally regulates J/A transition events in nematodes and mammals. Here, we uncover the targets and downstream pathways through which Caenorhabditis elegans let-7 controls male and female sexual organ morphogenesis and skin progenitor cell fates. We find that let-7 directs all three processes by silencing a single target, the post-transcriptional regulator lin-41. In turn, the RNA-binding protein LIN41/TRIM71 regulates these processes by silencing only four target mRNAs. Thus, by silencing LIN41, let-7 activates LIN-29a and MAB-10 (an early growth response-type transcription factor and its NAB1/2-orthologous cofactor, respectively) to terminate progenitor cell self-renewal and to promote vulval integrity. By contrast, let-7 promotes development of the male sexual organ by up-regulating DMD-3 and MAB-3, two Doublesex/MAB-3 domain–containing transcription factors. Our results provide mechanistic insight into how a linear chain of post-transcriptional regulators diverges in the control of a small set of transcriptional regulators to achieve a coordinated J/A transition. %U https://www.life-science-alliance.org/content/lsa/2/2/e201900335.full.pdf