Combinatorial RNA interference indicates GLH-4 can compensate for GLH-1; these two P granule components are critical for fertility in C. elegans

Development ◽  
2000 ◽  
Vol 127 (13) ◽  
pp. 2907-2916 ◽  
Author(s):  
K.A. Kuznicki ◽  
P.A. Smith ◽  
W.M. Leung-Chiu ◽  
A.O. Estevez ◽  
H.C. Scott ◽  
...  
Keyword(s):  
Rna Interference ◽  
Caenorhabditis Elegans ◽  
Pattern Formation ◽  
Zinc Fingers ◽  
Polar Granule ◽  
Rna Helicases ◽  
Germline Development ◽  
P Granules ◽  
C Elegans ◽  
Embryonic Pattern Formation

We report that four putative germline RNA helicases, GLHs, are components of the germline-specific P granules in Caenorhabditis elegans. GLH-3 and GLH-4, newly discovered, belong to a multi-gene glh family. Although GLHs are homologous to Drosophila VASA, a polar granule component necessary for oogenesis and embryonic pattern formation, the GLHs are distinguished by containing multiple CCHC zinc fingers. RNA-mediated interference (RNAi) reveals the GLHs are critical for oogenesis. By RNAi at 20 degrees C, when either loss of GLH-1 or GLH-4 alone has no effect, loss of both GLH-1 and GLH-4 results in 97% sterility in the glh-1/4(RNAi) offspring of injected hermaphrodites. glh-1/4(RNAi) germlines are under-proliferated and are without oocytes. glh-1/4(RNAi) animals produce sperm; however, spermatogenesis is delayed and the sperm are defective. P granules are still present in glh-1/4(RNAi) sterile worms as revealed with antibodies against the remaining GLH-2 and GLH-3 proteins, indicating the GLHs function independently in P granule assembly. These studies reveal that C.elegans can use GLH-1 or GLH-4 to promote germline development.

scholarly journals mRNA localization is linked to translation regulation in the Caenorhabditis elegans germ lineage

2020 ◽  
Author(s):  
Dylan M. Parker ◽  
Lindsay P. Winkenbach ◽  
Samuel P. Boyson ◽  
Matthew N. Saxton ◽  
Camryn Daidone ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Regulatory Control ◽  
Translational Repression ◽  
Translation Regulation ◽  
Germline Development ◽  
P Granules ◽  
C Elegans ◽  
Early Embryos

AbstractCaenorhabditis elegans early embryos generate cell-specific transcriptomes despite lacking active transcription. This presents an opportunity to study mechanisms of post-transcriptional regulatory control. In seeking the mechanisms behind this patterning, we discovered that some cell-specific mRNAs accumulate non-homogenously within cells, localizing to membranes, P granules (associated with progenitor germ cells in the P lineage), and P-bodies (associated with RNA processing). Transcripts differed in their dependence on 3’UTRs and RNA Binding Proteins, suggesting diverse regulatory mechanisms. Notably, we found strong but imperfect correlations between low translational status and P granule localization within the progenitor germ lineage. By uncoupling these, we untangled a long-standing question: Are mRNAs directed to P granules for translational repression or do they accumulate there as a downstream step? We found translational repression preceded P granule localization and could occur independent of it. Further, disruption of translation was sufficient to send homogenously distributed mRNAs to P granules. Overall, we show transcripts important for germline development are directed to P granules by translational repression, and this, in turn, directs their accumulation in the progenitor germ lineage where their repression can ultimately be relieved.SummaryMaternally loaded mRNAs localize non-homogeneously within C. elegans early embryos correlating with their translational status and lineage-specific fates.

scholarly journals HCP-4/CENP-C Promotes the Prophase Timing of Centromere Resolution by Enabling the Centromere Association of HCP-6 in Caenorhabditis elegans

2005 ◽  
Vol 25 (7) ◽  
pp. 2583-2592 ◽  
Author(s):  
Landon L. Moore ◽  
Gerald Stanvitch ◽  
Mark B. Roth ◽  
David Rosen
Keyword(s):  
Rna Interference ◽  
Caenorhabditis Elegans ◽  
Holocentric Chromosomes ◽  
Kinetochore Protein ◽  
C Elegans ◽  
Kinetochore Assembly ◽  
Centromere Protein ◽  
Sister Centromere ◽  
Microtubule Capture

ABSTRACT Prior to microtubule capture, sister centromeres resolve from one another, coming to rest on opposite surfaces of the condensing chromosome. Subsequent assembly of sister kinetochores at each sister centromere generates a geometry favorable for equal levels of segregation of chromatids. The holocentric chromosomes of Caenorhabditis elegans are uniquely suited for the study of centromere resolution and subsequent kinetochore assembly. In C. elegans, only two proteins have been identified as being necessary for centromere resolution, the kinase AIR-2 (prophase only) and the centromere protein HCP-4/CENP-C. Here we found that the loss of proteins involved in chromosome cohesion bypassed the requirement for HCP-4/CENP-C but not for AIR-2. Interestingly, the loss of cohesin proteins also restored the localization of HCP-6 to the kinetochore. The loss of the condensin II protein HCP-6 or MIX-1/SMC2 impaired centromere resolution. Furthermore, the loss of HCP-6 or MIX-1/SMC2 resulted in no centromere resolution when either nocodazole or RNA interference (RNAi) of the kinetochore protein KNL-1 perturbed spindle-kinetochore interactions. This result suggests that normal prophase centromere resolution is mediated by condensin II proteins, which are actively recruited to sister centromeres to mediate the process of resolution.

scholarly journals Inducible Systemic RNA Silencing in Caenorhabditis elegans

2003 ◽  
Vol 14 (7) ◽  
pp. 2972-2983 ◽  
Author(s):  
Lisa Timmons ◽  
Hiroaki Tabara ◽  
Craig C. Mello ◽  
Andrew Z. Fire
Keyword(s):  
Rna Interference ◽  
Caenorhabditis Elegans ◽  
Rna Silencing ◽  
Molecular Mechanisms ◽  
Normal Animal ◽  
Cell Types ◽  
Animal Cells ◽  
Tissue Specific ◽  
C Elegans ◽  
Systemic Rna

Introduction of double-stranded RNA (dsRNA) can elicit a gene-specific RNA interference response in a variety of organisms and cell types. In many cases, this response has a systemic character in that silencing of gene expression is observed in cells distal from the site of dsRNA delivery. The molecular mechanisms underlying the mobile nature of RNA silencing are unknown. For example, although cellular entry of dsRNA is possible, cellular exit of dsRNA from normal animal cells has not been directly observed. We provide evidence that transgenic strains of Caenorhabditis elegans transcribing dsRNA from a tissue-specific promoter do not exhibit comprehensive systemic RNA interference phenotypes. In these same animals, modifications of environmental conditions can result in more robust systemic RNA silencing. Additionally, we find that genetic mutations can influence the systemic character of RNA silencing in C. elegans and can separate mechanisms underlying systemic RNA silencing into tissue-specific components. These data suggest that trafficking of RNA silencing signals in C. elegans is regulated by specific physiological and genetic factors.

scholarly journals ATP-binding Cassette Transporters Are Required for Efficient RNA Interference in Caenorhabditis elegans

2006 ◽  
Vol 17 (8) ◽  
pp. 3678-3688 ◽  
Author(s):  
Prema Sundaram ◽  
Benjamin Echalier ◽  
Wang Han ◽  
Dawn Hull ◽  
Lisa Timmons
Keyword(s):  
Rna Interference ◽  
Caenorhabditis Elegans ◽  
Abc Transporters ◽  
Transport Systems ◽  
Atp Binding ◽  
C Elegans ◽  
Steep Concentration Gradient ◽  
Conserved Gene ◽  
Membrane Transport Systems ◽  
Atp Binding Cassette

RNA interference (RNAi) is a conserved gene-silencing phenomenon that can be triggered by delivery of double-stranded RNA (dsRNA) to cells and is a widely exploited technology in analyses of gene function. Although a number of proteins that facilitate RNAi have been identified, current descriptions of RNAi and interrelated mechanisms are far from complete. Here, we report that the Caenorhabditis elegans gene haf-6 is required for efficient RNAi. HAF-6 is a member of the ATP-binding cassette (ABC) transporter gene superfamily. ABC transporters use ATP to translocate small molecule substrates across the membranes in which they reside, often against a steep concentration gradient. Collectively, ABC transporters are involved in a variety of activities, including protective or barrier mechanisms that export drugs or toxins from cells, organellar biogenesis, and mechanisms that protect against viral infection. HAF-6 is expressed predominantly in the intestine and germline and is localized to intracellular reticular organelles. We further demonstrate that eight additional ABC genes from diverse subfamilies are each required for efficient RNAi in C. elegans. Thus, the ability to mount a robust RNAi response to dsRNA depends upon the deployment of two ancient systems that respond to environmental assaults: RNAi mechanisms and membrane transport systems that use ABC proteins.

A single histone H1 isoform (H1.1) is essential for chromatin silencing and germline development in Caenorhabditis elegans

Development ◽  
2001 ◽  
Vol 128 (7) ◽  
pp. 1069-1080 ◽  
Author(s):  
M.A. Jedrusik ◽  
E. Schulze
Keyword(s):  
Caenorhabditis Elegans ◽  
Gene Family ◽  
Molecular Mechanisms ◽  
Histone H1 ◽  
Specific Aspect ◽  
Polycomb Group ◽  
Germline Development ◽  
C Elegans ◽  
Proliferation And Differentiation ◽  
Germline Proliferation

In remarkable contrast to somatic cells, the germline of the nematode Caenorhabditis elegans efficiently silences transgenic DNA. The molecular mechanisms responsible for this have been shown to implicate chromatin proteins encoded by the mes genes (Kelly, W. G. and Fire, A. (1998) Development 125, 2451–2456), of which two are the C. elegans homologs of Polycomb Group gene transcriptional repressors. We have analyzed the contribution of the histone H1 gene family to this specific aspect of germ cells in C. elegans. We show with isotype-specific double stranded RNA-mediated interference (RNAi) that a single member of this gene family (H1.1) is essential for the repression of a silenced reporter-transgene in the germline of hermaphrodites and males, whereas no change is found in the somatic expression of this reporter. Additionally, RNA-mediated interference with H1.1 gene expression can cause a phenotype with severe affection of germline proliferation and differentiation in the hermaphrodite, and even sterility (5%-11% penetrance). These and further features observed in histone H1.1 RNAi experiments are also characteristic of the mes phenotype (Garvin, C., Holdeman, R. and Strome, S. (1998) Genetics 148, 167–185), which is believed to result from the desilencing of genes required for somatic differentiation in the germline. Our observations therefore support this interpretation of the mes phenotype and they identify a single histone H1 isoform (H1.1) as a new component specifically involved in chromatin silencing in the germline of C. elegans.

The Polycomb group in Caenorhabditis elegans and maternal control of germline development

Development ◽  
1998 ◽  
Vol 125 (13) ◽  
pp. 2469-2478 ◽  
Author(s):  
I. Korf ◽  
Y. Fan ◽  
S. Strome
Keyword(s):  
Gene Expression ◽  
Caenorhabditis Elegans ◽  
Polycomb Group ◽  
Polycomb Group Proteins ◽  
Polycomb Group Protein ◽  
Maternal Control ◽  
Germline Development ◽  
C Elegans ◽  
Polycomb Group Genes ◽  
Group Protein

Four Caenorhabditis elegans genes, mes-2, mes-3, mes-4 and mes-6, are essential for normal proliferation and viability of the germline. Mutations in these genes cause a maternal-effect sterile (i.e. mes) or grandchildless phenotype. We report that the mes-6 gene is in an unusual operon, the second example of this type of operon in C. elegans, and encodes the nematode homolog of Extra sex combs, a WD-40 protein in the Polycomb group in Drosophila. mes-2 encodes another Polycomb group protein (see paper by Holdeman, R., Nehrt, S. and Strome, S. (1998). Development 125, 2457–2467). Consistent with the known role of Polycomb group proteins in regulating gene expression, MES-6 is a nuclear protein. It is enriched in the germline of larvae and adults and is present in all nuclei of early embryos. Molecular epistasis results predict that the MES proteins, like Polycomb group proteins in Drosophila, function as a complex to regulate gene expression. Database searches reveal that there are considerably fewer Polycomb group genes in C. elegans than in Drosophila or vertebrates, and our studies suggest that their primary function is in controlling gene expression in the germline and ensuring the survival and proliferation of that tissue.

Segregation of germ granules in living Caenorhabditis elegans embryos: cell-type-specific mechanisms for cytoplasmic localisation

Development ◽  
1996 ◽  
Vol 122 (4) ◽  
pp. 1303-1312 ◽  
Author(s):  
S.N. Hird ◽  
J.E. Paulsen ◽  
S. Strome
Keyword(s):  
Caenorhabditis Elegans ◽  
Laser Scanning ◽  
Daughter Cell ◽  
Laser Scanning Confocal Microscopy ◽  
P Granules ◽  
C Elegans ◽  
Scanning Confocal Microscopy ◽  
Germ Granules ◽  
Cell Type Specific ◽  
P Cells

Germ granules are ribonucleoprotein particles that are thought to function in germline specification in invertebrates and possibly in vertebrates. In Caenorhabditis elegans, these structures, termed P granules, are partitioned to the germline P cells during the early embryonic divisions. By injecting a fluorescently labelled anti-P-granule antibody into the C. elegans germline syncitium, we followed P-granule segregation in live embryos using laser-scanning confocal microscopy. We show that, in early P cells (P0 and P1), P-granule partitioning is achieved primarily by their migration through the cytoplasm towards the site of formation of the germline daughter cell. A different mechanism appears to operate in later P cells (P2 and P3): P granules associate with the nucleus and move with it toward the site of formation of the germline daughter cell, where they are then deposited. At each division, there is also disassembly or degradation of those P granules that remain in the cytoplasm destined for the somatic daughter cell. Microfilaments, microtubules and the product of the gene mes-1 are required for the normal pattern of P-granule segregation in P2.

Uncover Genetic Interactions in Caenorhabditis elegans by RNA Interference

2005 ◽  
Vol 25 (5-6) ◽  
pp. 299-307 ◽  
Author(s):  
Angelo Fortunato ◽  
Andrew G. Fraser
Keyword(s):  
Rna Interference ◽  
Caenorhabditis Elegans ◽  
Gene Function ◽  
Genetic Interactions ◽  
Loss Of Function ◽  
Future Directions ◽  
C Elegans ◽  
Genomics Tools ◽  
Almost All ◽  
Nematode Worm

RNA-mediated interference (RNAi) has emerged recently as one of the most powerful functional genomics tools. RNAi has been particularly effective in the nematode worm C. elegans where RNAi has been used to analyse the loss-of-function phenotypes of almost all predicted genes. In this review, we illustrate how RNAi has been used to analyse gene function in C. elegans as well as pointing to some future directions for using RNAi to examine genetic interactions in a systematic manner.

scholarly journals Broadly conserved roles of TMEM131 family proteins in intracellular collagen assembly and secretory cargo trafficking

2020 ◽  
Vol 6 (7) ◽  
pp. eaay7667 ◽  
Author(s):  
Zhe Zhang ◽  
Meirong Bai ◽  
Guilherme Oliveira Barbosa ◽  
Andrew Chen ◽  
Yuehua Wei ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Rna Interference ◽  
Caenorhabditis Elegans ◽  
Stress Response ◽  
Er Stress ◽  
C Elegans ◽  
Er Stress Response ◽  
Evolutionarily Conserved ◽  
Human Disorders ◽  
Intracellular Collagen

Collagen is the most abundant protein in animals. Its dysregulation contributes to aging and many human disorders, including pathological tissue fibrosis in major organs. How premature collagen proteins in the endoplasmic reticulum (ER) assemble and route for secretion remains molecularly undefined. From an RNA interference screen, we identified an uncharacterized Caenorhabditis elegans gene tmem-131, deficiency of which impairs collagen production and activates ER stress response. We find that amino termini of human TMEM131 contain bacterial PapD chaperone–like domains, which recruit premature collagen monomers for proper assembly and secretion. Carboxy termini of TMEM131 interact with TRAPPC8, a component of the TRAPP tethering complex, to drive collagen cargo trafficking from ER to the Golgi. We provide evidence that previously undescribed roles of TMEM131 in collagen recruitment and secretion are evolutionarily conserved in C. elegans, Drosophila, and humans.

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