SynMuv B gene activity is down-regulated during a viral infection to enhance RNA interference.

Small RNA pathways regulate eukaryotic antiviral defense. Many of the mutations that were identified based on their enhanced RNAi, the synMuv B genes, also emerged from unrelated genetic screens for increased growth factor signaling. The dozen synMuv B genes encode homologues of the mammalian dREAM complex found in nearly all animals and plants, which includes the /retinoblastoma oncogene.

Feedback between a retinoid-related nuclear receptor and the microRNAs controls the pace and number of molting cycles in .

Animal development requires coordination among cyclic processes, sequential cell fate specifications, and once-a-lifetime morphogenic events, but the underlying timing mechanisms are not well understood. undergoes four molts at regular 8 to 10 hour intervals. The pace of the cycle is governed by PERIOD/ and other as-yet unknown factors.

daf-16/FOXO blocks adult cell fate in Caenorhabditis elegans dauer larvae via lin-41/TRIM71.

Many tissue-specific stem cells maintain the ability to produce multiple cell types during long periods of non-division, or quiescence. FOXO transcription factors promote quiescence and stem cell maintenance, but the mechanisms by which FOXO proteins promote multipotency during quiescence are still emerging. The single FOXO ortholog in C.

The multifaceted roles of microRNAs in differentiation.

MicroRNAs (miRNAs) are major drivers of cell fate specification and differentiation. The post-transcriptional regulation of key molecular factors by microRNAs contributes to the progression of embryonic and postembryonic development in several organisms. Following the discovery of lin-4 and let-7 in Caenorhabditis elegans and bantam microRNAs in Drosophila melanogaster, microRNAs have emerged as orchestrators of cellular differentiation and developmental timing.

miRISC Composition Determines Target Fates in Time and Space.

MicroRNA-mediated gene silencing can occur by either target mRNA degradation or translational repression. In this issue of Developmental Cell, Dallaire et al. (2018) show in C.