Project description:In nature, animals often face feast or famine conditions. We aimed to identify the miRNAs of Caenorhabditis elegans that changed their expression under starvation conditions in stage L4 larvae. Our results highlight 14 miRNAs that show differential expression in starved versus well-fed larvae. In particular, miRNAs of the miR-35-3p/miR-41-3p family were upregulated 6-20 fold upon starvation. We verified the upregulation of miR-35-3p with qPCR. Additionally, we showed that the expression of gld-1, important in ovogenesis, and a validated target of miR-35-3p, was downregulated when the expression of miR-35-3p was higher. This study represents a starting point for a more comprehensive understanding of the role of miRNAs during starvation in C. elegans.
Project description:Transcriptional profiling of N2 (WT) and miR-85(m4117) Caenorhabditis elegans at larval stage 4 (L4) compared at either control temperature (20°C) or after 3hr HS (35°C).
Project description:In nature, animals often face feast or famine conditions. We aimed to identify the miRNAs of Caenorhabditis elegans that changed their expression under starvation conditions in stage L4 larvae. Our results highlight 14 miRNAs that show differential expression in starved versus well-fed larvae. In particular, miRNAs of the miR-35-3p/miR-41-3p family were upregulated 6-20 fold upon starvation. We verified the upregulation of miR-35-3p with qPCR. Additionally, we showed that the expression of gld-1, important in ovogenesis, and a validated target of miR-35-3p, was downregulated when the expression of miR-35-3p was higher. This study represents a starting point for a more comprehensive understanding of the role of miRNAs during starvation in C. elegans. Illumina small RNA sequencing of starved and well-fed L4 worms.
Project description:Gene expression in early animal embryogenesis is in large part controlled post-transcriptionally. Maternally-contributed microRNAs may therefore play important roles in early development. We have elucidated a major biological role of the nematode mir-35 family of maternally-contributed, essential microRNAs. We show that this microRNA family regulates the sex determination pathway at multiple levels, acting both upstream and downstream of her-1 to prevent aberrantly activated male developmental programs in hermaphrodite embryos. The predicted target genes that act downstream of the mir-35 family in this process, sup-26 and nhl-2, both encode RNA binding proteins, thus delineating a previously unknown post-transcriptional regulatory subnetwork within the well-studied sex determination pathway of C. elegans. Repression of nhl-2 by the mir-35 family is not only required for proper sex determination but also for viability, showing that a single microRNA target site can be essential. Since sex determination in C. elegans requires zygotic gene expression to read the sex chromosome karyotype, early embryos must remain gender-naïve; our findings show that the mir-35 family microRNAs act in the early embryo to function as a developmental timer that preserves naïveté and prevents premature deleterious developmental decisions. The mir-35 family of microRNAs is essential for development. The mir-35-41(nDf50) allele deleted 7 of 8 mir-35 family members, and presents a hypomorphic phenotype in which embryonic lethality is temperature sensitive. To characterize the molecular phenotype associated with loss of mir-35 family function, we profiled gene expression in mir-35-41(nDf50) mutant embryos at both permissive (20) and restrictive (25) temperatures. (Refer to A microRNA family exerts maternal control on sex determination in C. elegans)
Project description:Gene expression in early animal embryogenesis is in large part controlled post-transcriptionally. Maternally-contributed microRNAs may therefore play important roles in early development. We have elucidated a major biological role of the nematode mir-35 family of maternally-contributed, essential microRNAs. We show that this microRNA family regulates the sex determination pathway at multiple levels, acting both upstream and downstream of her-1 to prevent aberrantly activated male developmental programs in hermaphrodite embryos. The predicted target genes that act downstream of the mir-35 family in this process, sup-26 and nhl-2, both encode RNA binding proteins, thus delineating a previously unknown post-transcriptional regulatory subnetwork within the well-studied sex determination pathway of C. elegans. Repression of nhl-2 by the mir-35 family is not only required for proper sex determination but also for viability, showing that a single microRNA target site can be essential. Since sex determination in C. elegans requires zygotic gene expression to read the sex chromosome karyotype, early embryos must remain gender-naïve; our findings show that the mir-35 family microRNAs act in the early embryo to function as a developmental timer that preserves naïveté and prevents premature deleterious developmental decisions. The mir-35 family of microRNAs is essential for development. The mir-35-41(nDf50) allele deleted 7 of 8 mir-35 family members, and presents a hypomorphic phenotype in which embryonic lethality is temperature sensitive. To characterize the molecular phenotype associated with loss of mir-35 family function, we profiled gene expression in mir-35-41(nDf50) mutant embryos at both permissive (20) and restrictive (25) temperatures. (Refer to A microRNA family exerts maternal control on sex determination in C. elegans)
Project description:After measuring the transcriptional response to increasing exposure of Caenorhabditis elegans N2 to 35 degrees Celsius, we wondered how recovery from heat-stress would progress. Hence, we exposed populations of the N2 strain to a 2 hour heat-shock of 35 degrees Celsius and took samples from 0 - 7 hours after termination of stress. This experiment was conduced in three biological replicates.
Project description:We compared animals that produce oocytes but no sperm fem-2(b245ts) to animals that produce sperm but no oocytes fem-3(q20ts). Using miRNA microarrays and we found that the mir-35-41 cluster genes were expressed to much greater extent in oogenesis than in spermatogenesis; furthermore, these miRNAs were the only C. elegans miRNAs that showed such differential germline expression.
Project description:The highly conserved DREAM transcriptional repressor complex contains an RB-like pocket protein, an E2F-DP transcription factor heterodimer, and the 5-subunit MuvB complex. Using CRISPR/Cas9 targeted mutagenesis, we disrupted the interaction between the sole Caenorhabditis elegans pocket protein LIN-35 and the MuvB subunit LIN-52. A triple alanine substitution of LIN-52's LxCxE motif (3A) severed LIN-35-MuvB association and caused classical DREAM mutant phenotypes, including synthetic multiple vulvae, high-temperature arrest, and ectopic expression of germline genes in the soma. We performed RNA-seq in lin-52(3A) mutant late embryos (4 replicates) compared to lin-52(WT) wild-type late embryos (4 replicates) to assess the genome-wide effects on gene expression that result from severing LIN-35-MuvB association.