Project description:Whole L1 larvae were collected from GC1459 [naSi2 [pGC550 (mex-5p::mCherry::H2B::nos-2 3'UTR +unc-119(+))] II; unc-119(ed3) III ?; daf-18(ok480) IV] and GC1171 [naSi2 [pGC550 (mex-5p::mCherry::H2B::nos-2 3'UTR +unc-119(+))] II; unc-119(ed3) III] strains up to two hours after hatching without food.
Project description:Animals integrate metabolic, developmental, and environmental information before committing key resources to reproduction. In C. elegans, adult animals reallocate key fat stores from intestinal cells to the germline via lipoproteins to promote reproduction. I identified the evolutionarily conserved homeodomain transcription factor CEH-60/PBX as a potent regulator of lipid homeostasis, longevity, and stress response pathways. To gain a comprehensive view of CEH-60 transcriptional activity, I profiled the transcriptomes of ceh-60 mutants by mRNA-Seq and identified genome-wide CEH-60 binding sites by ChIP-Seq. These approaches revealed that several homeostatic pathways are directly controlled by the CEH-60 transcription factor. CEH-60 functions cooperatively with UNC-62/MEIS in the intestine to directly activate lipoprotein genes while simultaneously repressing genes involved in stress responses, including the innate immune and oxidative stress responses. Thus in wild-type animals, CEH-60 serves as a molecular switch that promotes reproduction (i.e., lipoproteins) while repressing stress response and longevity pathways. This study identifies a new key regulator of fat metabolism, longevity, and stress response pathways during normal C. elegans development.
Project description:Animals integrate metabolic, developmental, and environmental information before committing key resources to reproduction. In C. elegans, adult animals reallocate key fat stores from intestinal cells to the germline via lipoproteins to promote reproduction. I identified the evolutionarily conserved homeodomain transcription factor CEH-60/PBX as a potent regulator of lipid homeostasis, longevity, and stress response pathways. To gain a comprehensive view of CEH-60 transcriptional activity, I profiled the transcriptomes of ceh-60 mutants by mRNA-Seq and identified genome-wide CEH-60 binding sites by ChIP-Seq. These approaches revealed that several homeostatic pathways are directly controlled by the CEH-60 transcription factor. CEH-60 functions cooperatively with UNC-62/MEIS in the intestine to directly activate lipoprotein genes while simultaneously repressing genes involved in stress responses, including the innate immune and oxidative stress responses. Thus in wild-type animals, CEH-60 serves as a molecular switch that promotes reproduction (i.e., lipoproteins) while repressing stress response and longevity pathways. This study identifies a new key regulator of fat metabolism, longevity, and stress response pathways during normal C. elegans development.
Project description:The double-stranded RNA-binding protein Staufen has been implicated in various posttranscriptional gene regulatory processes. Here, we demonstrate that the Caenorhabditis elegans homolog of Staufen, STAU-1, functionally interacts with microRNAs. Loss-of-function mutations of stau-1 significantly suppress phenotypes of let-7 family microRNA mutants, a hypomorphic allele of dicer and a lsy-6 microRNA partial loss-of-function mutant. Furthermore, STAU-1 modulates the activity of lin-14, a target of lin-4 and let-7 family microRNAs, and this modulation is abolished when the 3' untranslated region of lin-14 is removed. Deep sequencing of small RNA cDNA libraries reveals no dramatic change in the levels of microRNAs, or other small RNA populations between wild-type and stau-1 mutants, with the exception of certain endogenous siRNAs in the WAGO pathway. The modulation of microRNA activity by STAU-1 does not seem to be associated with the previously reported enhanced exogenous RNAi (Eri) phenotype of stau-1 mutants, since eri-1 exhibits the opposite effect on microRNA activity. Altogether, our results suggest that STAU-1 negatively modulates microRNA activity downstream of biogenesis, possibly by competing with microRNAs for binding on the 3' untranslated region of target mRNAs
Project description:The double-stranded RNA-binding protein Staufen has been implicated in various posttranscriptional gene regulatory processes. Here, we demonstrate that the Caenorhabditis elegans homolog of Staufen, STAU-1, functionally interacts with microRNAs. Loss-of-function mutations of stau-1 significantly suppress phenotypes of let-7 family microRNA mutants, a hypomorphic allele of dicer and a lsy-6 microRNA partial loss-of-function mutant. Furthermore, STAU-1 modulates the activity of lin-14, a target of lin-4 and let-7 family microRNAs, and this modulation is abolished when the 3' untranslated region of lin-14 is removed. Deep sequencing of small RNA cDNA libraries reveals no dramatic change in the levels of microRNAs, or other small RNA populations between wild-type and stau-1 mutants, with the exception of certain endogenous siRNAs in the WAGO pathway. The modulation of microRNA activity by STAU-1 does not seem to be associated with the previously reported enhanced exogenous RNAi (Eri) phenotype of stau-1 mutants, since eri-1 exhibits the opposite effect on microRNA activity. Altogether, our results suggest that STAU-1 negatively modulates microRNA activity downstream of biogenesis, possibly by competing with microRNAs for binding on the 3' untranslated region of target mRNAs Deep-sequencing was performed on cDNA libraries made from total RNA from young adults populations of two strains: wild-type (N2) and stau-1(tm2266), in three biological replicates each strain.